xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision 07cc2c93)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Note on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/ioport.h>
29 #include <linux/io.h>
30 #include <linux/platform_device.h>
31 #include <linux/init.h>
32 #include <linux/sysrq.h>
33 #include <linux/console.h>
34 #include <linux/tty.h>
35 #include <linux/tty_flip.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
38 #include <linux/serial_s3c.h>
39 #include <linux/delay.h>
40 #include <linux/clk.h>
41 #include <linux/cpufreq.h>
42 #include <linux/of.h>
43 #include <asm/irq.h>
44 
45 /* UART name and device definitions */
46 
47 #define S3C24XX_SERIAL_NAME	"ttySAC"
48 #define S3C24XX_SERIAL_MAJOR	204
49 #define S3C24XX_SERIAL_MINOR	64
50 
51 #ifdef CONFIG_ARM64
52 #define UART_NR			12
53 #else
54 #define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
55 #endif
56 
57 #define S3C24XX_TX_PIO			1
58 #define S3C24XX_TX_DMA			2
59 #define S3C24XX_RX_PIO			1
60 #define S3C24XX_RX_DMA			2
61 
62 /* flag to ignore all characters coming in */
63 #define RXSTAT_DUMMY_READ (0x10000000)
64 
65 enum s3c24xx_port_type {
66 	TYPE_S3C24XX,
67 	TYPE_S3C6400,
68 	TYPE_APPLE_S5L,
69 };
70 
71 struct s3c24xx_uart_info {
72 	const char		*name;
73 	enum s3c24xx_port_type	type;
74 	unsigned int		port_type;
75 	unsigned int		fifosize;
76 	unsigned long		rx_fifomask;
77 	unsigned long		rx_fifoshift;
78 	unsigned long		rx_fifofull;
79 	unsigned long		tx_fifomask;
80 	unsigned long		tx_fifoshift;
81 	unsigned long		tx_fifofull;
82 	unsigned int		def_clk_sel;
83 	unsigned long		num_clks;
84 	unsigned long		clksel_mask;
85 	unsigned long		clksel_shift;
86 	unsigned long		ucon_mask;
87 
88 	/* uart port features */
89 
90 	unsigned int		has_divslot:1;
91 };
92 
93 struct s3c24xx_serial_drv_data {
94 	const struct s3c24xx_uart_info	info;
95 	const struct s3c2410_uartcfg	def_cfg;
96 	const unsigned int		fifosize[UART_NR];
97 };
98 
99 struct s3c24xx_uart_dma {
100 	unsigned int			rx_chan_id;
101 	unsigned int			tx_chan_id;
102 
103 	struct dma_slave_config		rx_conf;
104 	struct dma_slave_config		tx_conf;
105 
106 	struct dma_chan			*rx_chan;
107 	struct dma_chan			*tx_chan;
108 
109 	dma_addr_t			rx_addr;
110 	dma_addr_t			tx_addr;
111 
112 	dma_cookie_t			rx_cookie;
113 	dma_cookie_t			tx_cookie;
114 
115 	char				*rx_buf;
116 
117 	dma_addr_t			tx_transfer_addr;
118 
119 	size_t				rx_size;
120 	size_t				tx_size;
121 
122 	struct dma_async_tx_descriptor	*tx_desc;
123 	struct dma_async_tx_descriptor	*rx_desc;
124 
125 	int				tx_bytes_requested;
126 	int				rx_bytes_requested;
127 };
128 
129 struct s3c24xx_uart_port {
130 	unsigned char			rx_claimed;
131 	unsigned char			tx_claimed;
132 	unsigned char			rx_enabled;
133 	unsigned char			tx_enabled;
134 	unsigned int			pm_level;
135 	unsigned long			baudclk_rate;
136 	unsigned int			min_dma_size;
137 
138 	unsigned int			rx_irq;
139 	unsigned int			tx_irq;
140 
141 	unsigned int			tx_in_progress;
142 	unsigned int			tx_mode;
143 	unsigned int			rx_mode;
144 
145 	const struct s3c24xx_uart_info	*info;
146 	struct clk			*clk;
147 	struct clk			*baudclk;
148 	struct uart_port		port;
149 	const struct s3c24xx_serial_drv_data	*drv_data;
150 
151 	/* reference to platform data */
152 	const struct s3c2410_uartcfg	*cfg;
153 
154 	struct s3c24xx_uart_dma		*dma;
155 
156 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
157 	struct notifier_block		freq_transition;
158 #endif
159 };
160 
161 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
162 
163 /* conversion functions */
164 
165 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
166 
167 /* register access controls */
168 
169 #define portaddr(port, reg) ((port)->membase + (reg))
170 #define portaddrl(port, reg) \
171 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
172 
173 static u32 rd_reg(const struct uart_port *port, u32 reg)
174 {
175 	switch (port->iotype) {
176 	case UPIO_MEM:
177 		return readb_relaxed(portaddr(port, reg));
178 	case UPIO_MEM32:
179 		return readl_relaxed(portaddr(port, reg));
180 	default:
181 		return 0;
182 	}
183 	return 0;
184 }
185 
186 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
187 
188 static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
189 {
190 	switch (port->iotype) {
191 	case UPIO_MEM:
192 		writeb_relaxed(val, portaddr(port, reg));
193 		break;
194 	case UPIO_MEM32:
195 		writel_relaxed(val, portaddr(port, reg));
196 		break;
197 	}
198 }
199 
200 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
201 
202 /* Byte-order aware bit setting/clearing functions. */
203 
204 static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
205 				   unsigned int reg)
206 {
207 	unsigned long flags;
208 	u32 val;
209 
210 	local_irq_save(flags);
211 	val = rd_regl(port, reg);
212 	val |= (1 << idx);
213 	wr_regl(port, reg, val);
214 	local_irq_restore(flags);
215 }
216 
217 static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
218 				     unsigned int reg)
219 {
220 	unsigned long flags;
221 	u32 val;
222 
223 	local_irq_save(flags);
224 	val = rd_regl(port, reg);
225 	val &= ~(1 << idx);
226 	wr_regl(port, reg, val);
227 	local_irq_restore(flags);
228 }
229 
230 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
231 {
232 	return container_of(port, struct s3c24xx_uart_port, port);
233 }
234 
235 /* translate a port to the device name */
236 
237 static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
238 {
239 	return to_platform_device(port->dev)->name;
240 }
241 
242 static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
243 {
244 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
245 }
246 
247 static void s3c24xx_serial_rx_enable(struct uart_port *port)
248 {
249 	struct s3c24xx_uart_port *ourport = to_ourport(port);
250 	unsigned long flags;
251 	unsigned int ucon, ufcon;
252 	int count = 10000;
253 
254 	spin_lock_irqsave(&port->lock, flags);
255 
256 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
257 		udelay(100);
258 
259 	ufcon = rd_regl(port, S3C2410_UFCON);
260 	ufcon |= S3C2410_UFCON_RESETRX;
261 	wr_regl(port, S3C2410_UFCON, ufcon);
262 
263 	ucon = rd_regl(port, S3C2410_UCON);
264 	ucon |= S3C2410_UCON_RXIRQMODE;
265 	wr_regl(port, S3C2410_UCON, ucon);
266 
267 	ourport->rx_enabled = 1;
268 	spin_unlock_irqrestore(&port->lock, flags);
269 }
270 
271 static void s3c24xx_serial_rx_disable(struct uart_port *port)
272 {
273 	struct s3c24xx_uart_port *ourport = to_ourport(port);
274 	unsigned long flags;
275 	unsigned int ucon;
276 
277 	spin_lock_irqsave(&port->lock, flags);
278 
279 	ucon = rd_regl(port, S3C2410_UCON);
280 	ucon &= ~S3C2410_UCON_RXIRQMODE;
281 	wr_regl(port, S3C2410_UCON, ucon);
282 
283 	ourport->rx_enabled = 0;
284 	spin_unlock_irqrestore(&port->lock, flags);
285 }
286 
287 static void s3c24xx_serial_stop_tx(struct uart_port *port)
288 {
289 	struct s3c24xx_uart_port *ourport = to_ourport(port);
290 	struct s3c24xx_uart_dma *dma = ourport->dma;
291 	struct dma_tx_state state;
292 	int count;
293 
294 	if (!ourport->tx_enabled)
295 		return;
296 
297 	switch (ourport->info->type) {
298 	case TYPE_S3C6400:
299 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
300 		break;
301 	case TYPE_APPLE_S5L:
302 		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
303 		break;
304 	default:
305 		disable_irq_nosync(ourport->tx_irq);
306 		break;
307 	}
308 
309 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
310 		dmaengine_pause(dma->tx_chan);
311 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
312 		dmaengine_terminate_all(dma->tx_chan);
313 		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
314 					dma->tx_transfer_addr, dma->tx_size,
315 					DMA_TO_DEVICE);
316 		async_tx_ack(dma->tx_desc);
317 		count = dma->tx_bytes_requested - state.residue;
318 		uart_xmit_advance(port, count);
319 	}
320 
321 	ourport->tx_enabled = 0;
322 	ourport->tx_in_progress = 0;
323 
324 	if (port->flags & UPF_CONS_FLOW)
325 		s3c24xx_serial_rx_enable(port);
326 
327 	ourport->tx_mode = 0;
328 }
329 
330 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
331 
332 static void s3c24xx_serial_tx_dma_complete(void *args)
333 {
334 	struct s3c24xx_uart_port *ourport = args;
335 	struct uart_port *port = &ourport->port;
336 	struct circ_buf *xmit = &port->state->xmit;
337 	struct s3c24xx_uart_dma *dma = ourport->dma;
338 	struct dma_tx_state state;
339 	unsigned long flags;
340 	int count;
341 
342 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
343 	count = dma->tx_bytes_requested - state.residue;
344 	async_tx_ack(dma->tx_desc);
345 
346 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
347 				dma->tx_transfer_addr, dma->tx_size,
348 				DMA_TO_DEVICE);
349 
350 	spin_lock_irqsave(&port->lock, flags);
351 
352 	uart_xmit_advance(port, count);
353 	ourport->tx_in_progress = 0;
354 
355 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
356 		uart_write_wakeup(port);
357 
358 	s3c24xx_serial_start_next_tx(ourport);
359 	spin_unlock_irqrestore(&port->lock, flags);
360 }
361 
362 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
363 {
364 	const struct uart_port *port = &ourport->port;
365 	u32 ucon;
366 
367 	/* Mask Tx interrupt */
368 	switch (ourport->info->type) {
369 	case TYPE_S3C6400:
370 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
371 		break;
372 	case TYPE_APPLE_S5L:
373 		WARN_ON(1); // No DMA
374 		break;
375 	default:
376 		disable_irq_nosync(ourport->tx_irq);
377 		break;
378 	}
379 
380 	/* Enable tx dma mode */
381 	ucon = rd_regl(port, S3C2410_UCON);
382 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
383 	ucon |= S3C64XX_UCON_TXBURST_1;
384 	ucon |= S3C64XX_UCON_TXMODE_DMA;
385 	wr_regl(port,  S3C2410_UCON, ucon);
386 
387 	ourport->tx_mode = S3C24XX_TX_DMA;
388 }
389 
390 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
391 {
392 	const struct uart_port *port = &ourport->port;
393 	u32 ucon, ufcon;
394 
395 	/* Set ufcon txtrig */
396 	ourport->tx_in_progress = S3C24XX_TX_PIO;
397 	ufcon = rd_regl(port, S3C2410_UFCON);
398 	wr_regl(port,  S3C2410_UFCON, ufcon);
399 
400 	/* Enable tx pio mode */
401 	ucon = rd_regl(port, S3C2410_UCON);
402 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
403 	ucon |= S3C64XX_UCON_TXMODE_CPU;
404 	wr_regl(port,  S3C2410_UCON, ucon);
405 
406 	/* Unmask Tx interrupt */
407 	switch (ourport->info->type) {
408 	case TYPE_S3C6400:
409 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
410 				  S3C64XX_UINTM);
411 		break;
412 	case TYPE_APPLE_S5L:
413 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
414 		wr_regl(port, S3C2410_UCON, ucon);
415 		break;
416 	default:
417 		enable_irq(ourport->tx_irq);
418 		break;
419 	}
420 
421 	ourport->tx_mode = S3C24XX_TX_PIO;
422 
423 	/*
424 	 * The Apple version only has edge triggered TX IRQs, so we need
425 	 * to kick off the process by sending some characters here.
426 	 */
427 	if (ourport->info->type == TYPE_APPLE_S5L)
428 		s3c24xx_serial_tx_chars(ourport);
429 }
430 
431 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
432 {
433 	if (ourport->tx_mode != S3C24XX_TX_PIO)
434 		enable_tx_pio(ourport);
435 }
436 
437 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
438 				      unsigned int count)
439 {
440 	struct uart_port *port = &ourport->port;
441 	struct circ_buf *xmit = &port->state->xmit;
442 	struct s3c24xx_uart_dma *dma = ourport->dma;
443 
444 	if (ourport->tx_mode != S3C24XX_TX_DMA)
445 		enable_tx_dma(ourport);
446 
447 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
448 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
449 
450 	dma_sync_single_for_device(dma->tx_chan->device->dev,
451 				   dma->tx_transfer_addr, dma->tx_size,
452 				   DMA_TO_DEVICE);
453 
454 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
455 				dma->tx_transfer_addr, dma->tx_size,
456 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
457 	if (!dma->tx_desc) {
458 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
459 		return -EIO;
460 	}
461 
462 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
463 	dma->tx_desc->callback_param = ourport;
464 	dma->tx_bytes_requested = dma->tx_size;
465 
466 	ourport->tx_in_progress = S3C24XX_TX_DMA;
467 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
468 	dma_async_issue_pending(dma->tx_chan);
469 	return 0;
470 }
471 
472 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
473 {
474 	struct uart_port *port = &ourport->port;
475 	struct circ_buf *xmit = &port->state->xmit;
476 	unsigned long count;
477 
478 	/* Get data size up to the end of buffer */
479 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
480 
481 	if (!count) {
482 		s3c24xx_serial_stop_tx(port);
483 		return;
484 	}
485 
486 	if (!ourport->dma || !ourport->dma->tx_chan ||
487 	    count < ourport->min_dma_size ||
488 	    xmit->tail & (dma_get_cache_alignment() - 1))
489 		s3c24xx_serial_start_tx_pio(ourport);
490 	else
491 		s3c24xx_serial_start_tx_dma(ourport, count);
492 }
493 
494 static void s3c24xx_serial_start_tx(struct uart_port *port)
495 {
496 	struct s3c24xx_uart_port *ourport = to_ourport(port);
497 	struct circ_buf *xmit = &port->state->xmit;
498 
499 	if (!ourport->tx_enabled) {
500 		if (port->flags & UPF_CONS_FLOW)
501 			s3c24xx_serial_rx_disable(port);
502 
503 		ourport->tx_enabled = 1;
504 		if (!ourport->dma || !ourport->dma->tx_chan)
505 			s3c24xx_serial_start_tx_pio(ourport);
506 	}
507 
508 	if (ourport->dma && ourport->dma->tx_chan) {
509 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
510 			s3c24xx_serial_start_next_tx(ourport);
511 	}
512 }
513 
514 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
515 		struct tty_port *tty, int count)
516 {
517 	struct s3c24xx_uart_dma *dma = ourport->dma;
518 	int copied;
519 
520 	if (!count)
521 		return;
522 
523 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
524 				dma->rx_size, DMA_FROM_DEVICE);
525 
526 	ourport->port.icount.rx += count;
527 	if (!tty) {
528 		dev_err(ourport->port.dev, "No tty port\n");
529 		return;
530 	}
531 	copied = tty_insert_flip_string(tty,
532 			((unsigned char *)(ourport->dma->rx_buf)), count);
533 	if (copied != count) {
534 		WARN_ON(1);
535 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
536 	}
537 }
538 
539 static void s3c24xx_serial_stop_rx(struct uart_port *port)
540 {
541 	struct s3c24xx_uart_port *ourport = to_ourport(port);
542 	struct s3c24xx_uart_dma *dma = ourport->dma;
543 	struct tty_port *t = &port->state->port;
544 	struct dma_tx_state state;
545 	enum dma_status dma_status;
546 	unsigned int received;
547 
548 	if (ourport->rx_enabled) {
549 		dev_dbg(port->dev, "stopping rx\n");
550 		switch (ourport->info->type) {
551 		case TYPE_S3C6400:
552 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
553 					S3C64XX_UINTM);
554 			break;
555 		case TYPE_APPLE_S5L:
556 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
557 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
558 			break;
559 		default:
560 			disable_irq_nosync(ourport->rx_irq);
561 			break;
562 		}
563 		ourport->rx_enabled = 0;
564 	}
565 	if (dma && dma->rx_chan) {
566 		dmaengine_pause(dma->tx_chan);
567 		dma_status = dmaengine_tx_status(dma->rx_chan,
568 				dma->rx_cookie, &state);
569 		if (dma_status == DMA_IN_PROGRESS ||
570 			dma_status == DMA_PAUSED) {
571 			received = dma->rx_bytes_requested - state.residue;
572 			dmaengine_terminate_all(dma->rx_chan);
573 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
574 		}
575 	}
576 }
577 
578 static inline const struct s3c24xx_uart_info
579 	*s3c24xx_port_to_info(struct uart_port *port)
580 {
581 	return to_ourport(port)->info;
582 }
583 
584 static inline const struct s3c2410_uartcfg
585 	*s3c24xx_port_to_cfg(const struct uart_port *port)
586 {
587 	const struct s3c24xx_uart_port *ourport;
588 
589 	if (port->dev == NULL)
590 		return NULL;
591 
592 	ourport = container_of(port, struct s3c24xx_uart_port, port);
593 	return ourport->cfg;
594 }
595 
596 static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
597 				     unsigned long ufstat)
598 {
599 	const struct s3c24xx_uart_info *info = ourport->info;
600 
601 	if (ufstat & info->rx_fifofull)
602 		return ourport->port.fifosize;
603 
604 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
605 }
606 
607 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
608 static void s3c24xx_serial_rx_dma_complete(void *args)
609 {
610 	struct s3c24xx_uart_port *ourport = args;
611 	struct uart_port *port = &ourport->port;
612 
613 	struct s3c24xx_uart_dma *dma = ourport->dma;
614 	struct tty_port *t = &port->state->port;
615 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
616 
617 	struct dma_tx_state state;
618 	unsigned long flags;
619 	int received;
620 
621 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
622 	received  = dma->rx_bytes_requested - state.residue;
623 	async_tx_ack(dma->rx_desc);
624 
625 	spin_lock_irqsave(&port->lock, flags);
626 
627 	if (received)
628 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
629 
630 	if (tty) {
631 		tty_flip_buffer_push(t);
632 		tty_kref_put(tty);
633 	}
634 
635 	s3c64xx_start_rx_dma(ourport);
636 
637 	spin_unlock_irqrestore(&port->lock, flags);
638 }
639 
640 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
641 {
642 	struct s3c24xx_uart_dma *dma = ourport->dma;
643 
644 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
645 				   dma->rx_size, DMA_FROM_DEVICE);
646 
647 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
648 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
649 				DMA_PREP_INTERRUPT);
650 	if (!dma->rx_desc) {
651 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
652 		return;
653 	}
654 
655 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
656 	dma->rx_desc->callback_param = ourport;
657 	dma->rx_bytes_requested = dma->rx_size;
658 
659 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
660 	dma_async_issue_pending(dma->rx_chan);
661 }
662 
663 /* ? - where has parity gone?? */
664 #define S3C2410_UERSTAT_PARITY (0x1000)
665 
666 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
667 {
668 	struct uart_port *port = &ourport->port;
669 	unsigned int ucon;
670 
671 	/* set Rx mode to DMA mode */
672 	ucon = rd_regl(port, S3C2410_UCON);
673 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
674 			S3C64XX_UCON_TIMEOUT_MASK |
675 			S3C64XX_UCON_EMPTYINT_EN |
676 			S3C64XX_UCON_DMASUS_EN |
677 			S3C64XX_UCON_TIMEOUT_EN |
678 			S3C64XX_UCON_RXMODE_MASK);
679 	ucon |= S3C64XX_UCON_RXBURST_1 |
680 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
681 			S3C64XX_UCON_EMPTYINT_EN |
682 			S3C64XX_UCON_TIMEOUT_EN |
683 			S3C64XX_UCON_RXMODE_DMA;
684 	wr_regl(port, S3C2410_UCON, ucon);
685 
686 	ourport->rx_mode = S3C24XX_RX_DMA;
687 }
688 
689 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
690 {
691 	struct uart_port *port = &ourport->port;
692 	unsigned int ucon;
693 
694 	/* set Rx mode to DMA mode */
695 	ucon = rd_regl(port, S3C2410_UCON);
696 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
697 	ucon |= S3C64XX_UCON_RXMODE_CPU;
698 
699 	/* Apple types use these bits for IRQ masks */
700 	if (ourport->info->type != TYPE_APPLE_S5L) {
701 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
702 				S3C64XX_UCON_EMPTYINT_EN |
703 				S3C64XX_UCON_DMASUS_EN |
704 				S3C64XX_UCON_TIMEOUT_EN);
705 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
706 				S3C64XX_UCON_TIMEOUT_EN;
707 	}
708 	wr_regl(port, S3C2410_UCON, ucon);
709 
710 	ourport->rx_mode = S3C24XX_RX_PIO;
711 }
712 
713 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
714 
715 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
716 {
717 	unsigned int utrstat, received;
718 	struct s3c24xx_uart_port *ourport = dev_id;
719 	struct uart_port *port = &ourport->port;
720 	struct s3c24xx_uart_dma *dma = ourport->dma;
721 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
722 	struct tty_port *t = &port->state->port;
723 	struct dma_tx_state state;
724 
725 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
726 	rd_regl(port, S3C2410_UFSTAT);
727 
728 	spin_lock(&port->lock);
729 
730 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
731 		s3c64xx_start_rx_dma(ourport);
732 		if (ourport->rx_mode == S3C24XX_RX_PIO)
733 			enable_rx_dma(ourport);
734 		goto finish;
735 	}
736 
737 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
738 		dmaengine_pause(dma->rx_chan);
739 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
740 		dmaengine_terminate_all(dma->rx_chan);
741 		received = dma->rx_bytes_requested - state.residue;
742 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
743 
744 		enable_rx_pio(ourport);
745 	}
746 
747 	s3c24xx_serial_rx_drain_fifo(ourport);
748 
749 	if (tty) {
750 		tty_flip_buffer_push(t);
751 		tty_kref_put(tty);
752 	}
753 
754 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
755 
756 finish:
757 	spin_unlock(&port->lock);
758 
759 	return IRQ_HANDLED;
760 }
761 
762 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
763 {
764 	struct uart_port *port = &ourport->port;
765 	unsigned int ufcon, ch, flag, ufstat, uerstat;
766 	unsigned int fifocnt = 0;
767 	int max_count = port->fifosize;
768 
769 	while (max_count-- > 0) {
770 		/*
771 		 * Receive all characters known to be in FIFO
772 		 * before reading FIFO level again
773 		 */
774 		if (fifocnt == 0) {
775 			ufstat = rd_regl(port, S3C2410_UFSTAT);
776 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
777 			if (fifocnt == 0)
778 				break;
779 		}
780 		fifocnt--;
781 
782 		uerstat = rd_regl(port, S3C2410_UERSTAT);
783 		ch = rd_reg(port, S3C2410_URXH);
784 
785 		if (port->flags & UPF_CONS_FLOW) {
786 			int txe = s3c24xx_serial_txempty_nofifo(port);
787 
788 			if (ourport->rx_enabled) {
789 				if (!txe) {
790 					ourport->rx_enabled = 0;
791 					continue;
792 				}
793 			} else {
794 				if (txe) {
795 					ufcon = rd_regl(port, S3C2410_UFCON);
796 					ufcon |= S3C2410_UFCON_RESETRX;
797 					wr_regl(port, S3C2410_UFCON, ufcon);
798 					ourport->rx_enabled = 1;
799 					return;
800 				}
801 				continue;
802 			}
803 		}
804 
805 		/* insert the character into the buffer */
806 
807 		flag = TTY_NORMAL;
808 		port->icount.rx++;
809 
810 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
811 			dev_dbg(port->dev,
812 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
813 				ch, uerstat);
814 
815 			/* check for break */
816 			if (uerstat & S3C2410_UERSTAT_BREAK) {
817 				dev_dbg(port->dev, "break!\n");
818 				port->icount.brk++;
819 				if (uart_handle_break(port))
820 					continue; /* Ignore character */
821 			}
822 
823 			if (uerstat & S3C2410_UERSTAT_FRAME)
824 				port->icount.frame++;
825 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
826 				port->icount.overrun++;
827 
828 			uerstat &= port->read_status_mask;
829 
830 			if (uerstat & S3C2410_UERSTAT_BREAK)
831 				flag = TTY_BREAK;
832 			else if (uerstat & S3C2410_UERSTAT_PARITY)
833 				flag = TTY_PARITY;
834 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
835 					    S3C2410_UERSTAT_OVERRUN))
836 				flag = TTY_FRAME;
837 		}
838 
839 		if (uart_handle_sysrq_char(port, ch))
840 			continue; /* Ignore character */
841 
842 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
843 				 ch, flag);
844 	}
845 
846 	tty_flip_buffer_push(&port->state->port);
847 }
848 
849 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
850 {
851 	struct s3c24xx_uart_port *ourport = dev_id;
852 	struct uart_port *port = &ourport->port;
853 
854 	spin_lock(&port->lock);
855 	s3c24xx_serial_rx_drain_fifo(ourport);
856 	spin_unlock(&port->lock);
857 
858 	return IRQ_HANDLED;
859 }
860 
861 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
862 {
863 	struct s3c24xx_uart_port *ourport = dev_id;
864 
865 	if (ourport->dma && ourport->dma->rx_chan)
866 		return s3c24xx_serial_rx_chars_dma(dev_id);
867 	return s3c24xx_serial_rx_chars_pio(dev_id);
868 }
869 
870 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
871 {
872 	struct uart_port *port = &ourport->port;
873 	struct circ_buf *xmit = &port->state->xmit;
874 	int count, dma_count = 0;
875 
876 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
877 
878 	if (ourport->dma && ourport->dma->tx_chan &&
879 	    count >= ourport->min_dma_size) {
880 		int align = dma_get_cache_alignment() -
881 			(xmit->tail & (dma_get_cache_alignment() - 1));
882 		if (count - align >= ourport->min_dma_size) {
883 			dma_count = count - align;
884 			count = align;
885 		}
886 	}
887 
888 	if (port->x_char) {
889 		wr_reg(port, S3C2410_UTXH, port->x_char);
890 		port->icount.tx++;
891 		port->x_char = 0;
892 		return;
893 	}
894 
895 	/* if there isn't anything more to transmit, or the uart is now
896 	 * stopped, disable the uart and exit
897 	 */
898 
899 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
900 		s3c24xx_serial_stop_tx(port);
901 		return;
902 	}
903 
904 	/* try and drain the buffer... */
905 
906 	if (count > port->fifosize) {
907 		count = port->fifosize;
908 		dma_count = 0;
909 	}
910 
911 	while (!uart_circ_empty(xmit) && count > 0) {
912 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
913 			break;
914 
915 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
916 		uart_xmit_advance(port, 1);
917 		count--;
918 	}
919 
920 	if (!count && dma_count) {
921 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
922 		return;
923 	}
924 
925 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
926 		uart_write_wakeup(port);
927 
928 	if (uart_circ_empty(xmit))
929 		s3c24xx_serial_stop_tx(port);
930 }
931 
932 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
933 {
934 	struct s3c24xx_uart_port *ourport = id;
935 	struct uart_port *port = &ourport->port;
936 
937 	spin_lock(&port->lock);
938 
939 	s3c24xx_serial_tx_chars(ourport);
940 
941 	spin_unlock(&port->lock);
942 	return IRQ_HANDLED;
943 }
944 
945 /* interrupt handler for s3c64xx and later SoC's.*/
946 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
947 {
948 	const struct s3c24xx_uart_port *ourport = id;
949 	const struct uart_port *port = &ourport->port;
950 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
951 	irqreturn_t ret = IRQ_HANDLED;
952 
953 	if (pend & S3C64XX_UINTM_RXD_MSK) {
954 		ret = s3c24xx_serial_rx_irq(irq, id);
955 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
956 	}
957 	if (pend & S3C64XX_UINTM_TXD_MSK) {
958 		ret = s3c24xx_serial_tx_irq(irq, id);
959 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
960 	}
961 	return ret;
962 }
963 
964 /* interrupt handler for Apple SoC's.*/
965 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
966 {
967 	const struct s3c24xx_uart_port *ourport = id;
968 	const struct uart_port *port = &ourport->port;
969 	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
970 	irqreturn_t ret = IRQ_NONE;
971 
972 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
973 		wr_regl(port, S3C2410_UTRSTAT,
974 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
975 		ret = s3c24xx_serial_rx_irq(irq, id);
976 	}
977 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
978 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
979 		ret = s3c24xx_serial_tx_irq(irq, id);
980 	}
981 
982 	return ret;
983 }
984 
985 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
986 {
987 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
988 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
989 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
990 
991 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
992 		if ((ufstat & info->tx_fifomask) != 0 ||
993 		    (ufstat & info->tx_fifofull))
994 			return 0;
995 
996 		return 1;
997 	}
998 
999 	return s3c24xx_serial_txempty_nofifo(port);
1000 }
1001 
1002 /* no modem control lines */
1003 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1004 {
1005 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
1006 
1007 	if (umstat & S3C2410_UMSTAT_CTS)
1008 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1009 	else
1010 		return TIOCM_CAR | TIOCM_DSR;
1011 }
1012 
1013 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1014 {
1015 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
1016 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
1017 
1018 	if (mctrl & TIOCM_RTS)
1019 		umcon |= S3C2410_UMCOM_RTS_LOW;
1020 	else
1021 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1022 
1023 	wr_regl(port, S3C2410_UMCON, umcon);
1024 
1025 	if (mctrl & TIOCM_LOOP)
1026 		ucon |= S3C2410_UCON_LOOPBACK;
1027 	else
1028 		ucon &= ~S3C2410_UCON_LOOPBACK;
1029 
1030 	wr_regl(port, S3C2410_UCON, ucon);
1031 }
1032 
1033 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1034 {
1035 	unsigned long flags;
1036 	unsigned int ucon;
1037 
1038 	spin_lock_irqsave(&port->lock, flags);
1039 
1040 	ucon = rd_regl(port, S3C2410_UCON);
1041 
1042 	if (break_state)
1043 		ucon |= S3C2410_UCON_SBREAK;
1044 	else
1045 		ucon &= ~S3C2410_UCON_SBREAK;
1046 
1047 	wr_regl(port, S3C2410_UCON, ucon);
1048 
1049 	spin_unlock_irqrestore(&port->lock, flags);
1050 }
1051 
1052 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1053 {
1054 	struct s3c24xx_uart_dma	*dma = p->dma;
1055 	struct dma_slave_caps dma_caps;
1056 	const char *reason = NULL;
1057 	int ret;
1058 
1059 	/* Default slave configuration parameters */
1060 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1061 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1062 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1063 	dma->rx_conf.src_maxburst	= 1;
1064 
1065 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1066 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1067 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1068 	dma->tx_conf.dst_maxburst	= 1;
1069 
1070 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1071 
1072 	if (IS_ERR(dma->rx_chan)) {
1073 		reason = "DMA RX channel request failed";
1074 		ret = PTR_ERR(dma->rx_chan);
1075 		goto err_warn;
1076 	}
1077 
1078 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1079 	if (ret < 0 ||
1080 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1081 		reason = "insufficient DMA RX engine capabilities";
1082 		ret = -EOPNOTSUPP;
1083 		goto err_release_rx;
1084 	}
1085 
1086 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1087 
1088 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1089 	if (IS_ERR(dma->tx_chan)) {
1090 		reason = "DMA TX channel request failed";
1091 		ret = PTR_ERR(dma->tx_chan);
1092 		goto err_release_rx;
1093 	}
1094 
1095 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1096 	if (ret < 0 ||
1097 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1098 		reason = "insufficient DMA TX engine capabilities";
1099 		ret = -EOPNOTSUPP;
1100 		goto err_release_tx;
1101 	}
1102 
1103 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1104 
1105 	/* RX buffer */
1106 	dma->rx_size = PAGE_SIZE;
1107 
1108 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1109 	if (!dma->rx_buf) {
1110 		ret = -ENOMEM;
1111 		goto err_release_tx;
1112 	}
1113 
1114 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1115 				      dma->rx_size, DMA_FROM_DEVICE);
1116 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1117 		reason = "DMA mapping error for RX buffer";
1118 		ret = -EIO;
1119 		goto err_free_rx;
1120 	}
1121 
1122 	/* TX buffer */
1123 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1124 				      p->port.state->xmit.buf, UART_XMIT_SIZE,
1125 				      DMA_TO_DEVICE);
1126 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1127 		reason = "DMA mapping error for TX buffer";
1128 		ret = -EIO;
1129 		goto err_unmap_rx;
1130 	}
1131 
1132 	return 0;
1133 
1134 err_unmap_rx:
1135 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1136 			 dma->rx_size, DMA_FROM_DEVICE);
1137 err_free_rx:
1138 	kfree(dma->rx_buf);
1139 err_release_tx:
1140 	dma_release_channel(dma->tx_chan);
1141 err_release_rx:
1142 	dma_release_channel(dma->rx_chan);
1143 err_warn:
1144 	if (reason)
1145 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1146 	return ret;
1147 }
1148 
1149 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1150 {
1151 	struct s3c24xx_uart_dma	*dma = p->dma;
1152 
1153 	if (dma->rx_chan) {
1154 		dmaengine_terminate_all(dma->rx_chan);
1155 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1156 				 dma->rx_size, DMA_FROM_DEVICE);
1157 		kfree(dma->rx_buf);
1158 		dma_release_channel(dma->rx_chan);
1159 		dma->rx_chan = NULL;
1160 	}
1161 
1162 	if (dma->tx_chan) {
1163 		dmaengine_terminate_all(dma->tx_chan);
1164 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1165 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1166 		dma_release_channel(dma->tx_chan);
1167 		dma->tx_chan = NULL;
1168 	}
1169 }
1170 
1171 static void s3c24xx_serial_shutdown(struct uart_port *port)
1172 {
1173 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1174 
1175 	if (ourport->tx_claimed) {
1176 		free_irq(ourport->tx_irq, ourport);
1177 		ourport->tx_enabled = 0;
1178 		ourport->tx_claimed = 0;
1179 		ourport->tx_mode = 0;
1180 	}
1181 
1182 	if (ourport->rx_claimed) {
1183 		free_irq(ourport->rx_irq, ourport);
1184 		ourport->rx_claimed = 0;
1185 		ourport->rx_enabled = 0;
1186 	}
1187 
1188 	if (ourport->dma)
1189 		s3c24xx_serial_release_dma(ourport);
1190 
1191 	ourport->tx_in_progress = 0;
1192 }
1193 
1194 static void s3c64xx_serial_shutdown(struct uart_port *port)
1195 {
1196 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1197 
1198 	ourport->tx_enabled = 0;
1199 	ourport->tx_mode = 0;
1200 	ourport->rx_enabled = 0;
1201 
1202 	free_irq(port->irq, ourport);
1203 
1204 	wr_regl(port, S3C64XX_UINTP, 0xf);
1205 	wr_regl(port, S3C64XX_UINTM, 0xf);
1206 
1207 	if (ourport->dma)
1208 		s3c24xx_serial_release_dma(ourport);
1209 
1210 	ourport->tx_in_progress = 0;
1211 }
1212 
1213 static void apple_s5l_serial_shutdown(struct uart_port *port)
1214 {
1215 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1216 
1217 	unsigned int ucon;
1218 
1219 	ucon = rd_regl(port, S3C2410_UCON);
1220 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1221 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1222 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1223 	wr_regl(port, S3C2410_UCON, ucon);
1224 
1225 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1226 
1227 	free_irq(port->irq, ourport);
1228 
1229 	ourport->tx_enabled = 0;
1230 	ourport->tx_mode = 0;
1231 	ourport->rx_enabled = 0;
1232 
1233 	if (ourport->dma)
1234 		s3c24xx_serial_release_dma(ourport);
1235 
1236 	ourport->tx_in_progress = 0;
1237 }
1238 
1239 static int s3c24xx_serial_startup(struct uart_port *port)
1240 {
1241 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1242 	int ret;
1243 
1244 	ourport->rx_enabled = 1;
1245 
1246 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
1247 			  s3c24xx_serial_portname(port), ourport);
1248 
1249 	if (ret != 0) {
1250 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1251 		return ret;
1252 	}
1253 
1254 	ourport->rx_claimed = 1;
1255 
1256 	dev_dbg(port->dev, "requesting tx irq...\n");
1257 
1258 	ourport->tx_enabled = 1;
1259 
1260 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
1261 			  s3c24xx_serial_portname(port), ourport);
1262 
1263 	if (ret) {
1264 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1265 		goto err;
1266 	}
1267 
1268 	ourport->tx_claimed = 1;
1269 
1270 	/* the port reset code should have done the correct
1271 	 * register setup for the port controls
1272 	 */
1273 
1274 	return ret;
1275 
1276 err:
1277 	s3c24xx_serial_shutdown(port);
1278 	return ret;
1279 }
1280 
1281 static int s3c64xx_serial_startup(struct uart_port *port)
1282 {
1283 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1284 	unsigned long flags;
1285 	unsigned int ufcon;
1286 	int ret;
1287 
1288 	wr_regl(port, S3C64XX_UINTM, 0xf);
1289 	if (ourport->dma) {
1290 		ret = s3c24xx_serial_request_dma(ourport);
1291 		if (ret < 0) {
1292 			devm_kfree(port->dev, ourport->dma);
1293 			ourport->dma = NULL;
1294 		}
1295 	}
1296 
1297 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1298 			  s3c24xx_serial_portname(port), ourport);
1299 	if (ret) {
1300 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1301 		return ret;
1302 	}
1303 
1304 	/* For compatibility with s3c24xx Soc's */
1305 	ourport->rx_enabled = 1;
1306 	ourport->tx_enabled = 0;
1307 
1308 	spin_lock_irqsave(&port->lock, flags);
1309 
1310 	ufcon = rd_regl(port, S3C2410_UFCON);
1311 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1312 	if (!uart_console(port))
1313 		ufcon |= S3C2410_UFCON_RESETTX;
1314 	wr_regl(port, S3C2410_UFCON, ufcon);
1315 
1316 	enable_rx_pio(ourport);
1317 
1318 	spin_unlock_irqrestore(&port->lock, flags);
1319 
1320 	/* Enable Rx Interrupt */
1321 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1322 
1323 	return ret;
1324 }
1325 
1326 static int apple_s5l_serial_startup(struct uart_port *port)
1327 {
1328 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1329 	unsigned long flags;
1330 	unsigned int ufcon;
1331 	int ret;
1332 
1333 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1334 
1335 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1336 			  s3c24xx_serial_portname(port), ourport);
1337 	if (ret) {
1338 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1339 		return ret;
1340 	}
1341 
1342 	/* For compatibility with s3c24xx Soc's */
1343 	ourport->rx_enabled = 1;
1344 	ourport->tx_enabled = 0;
1345 
1346 	spin_lock_irqsave(&port->lock, flags);
1347 
1348 	ufcon = rd_regl(port, S3C2410_UFCON);
1349 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1350 	if (!uart_console(port))
1351 		ufcon |= S3C2410_UFCON_RESETTX;
1352 	wr_regl(port, S3C2410_UFCON, ufcon);
1353 
1354 	enable_rx_pio(ourport);
1355 
1356 	spin_unlock_irqrestore(&port->lock, flags);
1357 
1358 	/* Enable Rx Interrupt */
1359 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1360 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1361 
1362 	return ret;
1363 }
1364 
1365 /* power power management control */
1366 
1367 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1368 			      unsigned int old)
1369 {
1370 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1371 	int timeout = 10000;
1372 
1373 	ourport->pm_level = level;
1374 
1375 	switch (level) {
1376 	case 3:
1377 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1378 			udelay(100);
1379 
1380 		if (!IS_ERR(ourport->baudclk))
1381 			clk_disable_unprepare(ourport->baudclk);
1382 
1383 		clk_disable_unprepare(ourport->clk);
1384 		break;
1385 
1386 	case 0:
1387 		clk_prepare_enable(ourport->clk);
1388 
1389 		if (!IS_ERR(ourport->baudclk))
1390 			clk_prepare_enable(ourport->baudclk);
1391 		break;
1392 	default:
1393 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1394 	}
1395 }
1396 
1397 /* baud rate calculation
1398  *
1399  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1400  * of different sources, including the peripheral clock ("pclk") and an
1401  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1402  * with a programmable extra divisor.
1403  *
1404  * The following code goes through the clock sources, and calculates the
1405  * baud clocks (and the resultant actual baud rates) and then tries to
1406  * pick the closest one and select that.
1407  *
1408  */
1409 
1410 #define MAX_CLK_NAME_LENGTH 15
1411 
1412 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1413 {
1414 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1415 	unsigned int ucon;
1416 
1417 	if (info->num_clks == 1)
1418 		return 0;
1419 
1420 	ucon = rd_regl(port, S3C2410_UCON);
1421 	ucon &= info->clksel_mask;
1422 	return ucon >> info->clksel_shift;
1423 }
1424 
1425 static void s3c24xx_serial_setsource(struct uart_port *port,
1426 			unsigned int clk_sel)
1427 {
1428 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1429 	unsigned int ucon;
1430 
1431 	if (info->num_clks == 1)
1432 		return;
1433 
1434 	ucon = rd_regl(port, S3C2410_UCON);
1435 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1436 		return;
1437 
1438 	ucon &= ~info->clksel_mask;
1439 	ucon |= clk_sel << info->clksel_shift;
1440 	wr_regl(port, S3C2410_UCON, ucon);
1441 }
1442 
1443 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1444 			unsigned int req_baud, struct clk **best_clk,
1445 			unsigned int *clk_num)
1446 {
1447 	const struct s3c24xx_uart_info *info = ourport->info;
1448 	struct clk *clk;
1449 	unsigned long rate;
1450 	unsigned int cnt, baud, quot, best_quot = 0;
1451 	char clkname[MAX_CLK_NAME_LENGTH];
1452 	int calc_deviation, deviation = (1 << 30) - 1;
1453 
1454 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1455 		/* Keep selected clock if provided */
1456 		if (ourport->cfg->clk_sel &&
1457 			!(ourport->cfg->clk_sel & (1 << cnt)))
1458 			continue;
1459 
1460 		sprintf(clkname, "clk_uart_baud%d", cnt);
1461 		clk = clk_get(ourport->port.dev, clkname);
1462 		if (IS_ERR(clk))
1463 			continue;
1464 
1465 		rate = clk_get_rate(clk);
1466 		if (!rate)
1467 			continue;
1468 
1469 		if (ourport->info->has_divslot) {
1470 			unsigned long div = rate / req_baud;
1471 
1472 			/* The UDIVSLOT register on the newer UARTs allows us to
1473 			 * get a divisor adjustment of 1/16th on the baud clock.
1474 			 *
1475 			 * We don't keep the UDIVSLOT value (the 16ths we
1476 			 * calculated by not multiplying the baud by 16) as it
1477 			 * is easy enough to recalculate.
1478 			 */
1479 
1480 			quot = div / 16;
1481 			baud = rate / div;
1482 		} else {
1483 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1484 			baud = rate / (quot * 16);
1485 		}
1486 		quot--;
1487 
1488 		calc_deviation = req_baud - baud;
1489 		if (calc_deviation < 0)
1490 			calc_deviation = -calc_deviation;
1491 
1492 		if (calc_deviation < deviation) {
1493 			*best_clk = clk;
1494 			best_quot = quot;
1495 			*clk_num = cnt;
1496 			deviation = calc_deviation;
1497 		}
1498 	}
1499 
1500 	return best_quot;
1501 }
1502 
1503 /* udivslot_table[]
1504  *
1505  * This table takes the fractional value of the baud divisor and gives
1506  * the recommended setting for the UDIVSLOT register.
1507  */
1508 static const u16 udivslot_table[16] = {
1509 	[0] = 0x0000,
1510 	[1] = 0x0080,
1511 	[2] = 0x0808,
1512 	[3] = 0x0888,
1513 	[4] = 0x2222,
1514 	[5] = 0x4924,
1515 	[6] = 0x4A52,
1516 	[7] = 0x54AA,
1517 	[8] = 0x5555,
1518 	[9] = 0xD555,
1519 	[10] = 0xD5D5,
1520 	[11] = 0xDDD5,
1521 	[12] = 0xDDDD,
1522 	[13] = 0xDFDD,
1523 	[14] = 0xDFDF,
1524 	[15] = 0xFFDF,
1525 };
1526 
1527 static void s3c24xx_serial_set_termios(struct uart_port *port,
1528 				       struct ktermios *termios,
1529 				       const struct ktermios *old)
1530 {
1531 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1532 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1533 	struct clk *clk = ERR_PTR(-EINVAL);
1534 	unsigned long flags;
1535 	unsigned int baud, quot, clk_sel = 0;
1536 	unsigned int ulcon;
1537 	unsigned int umcon;
1538 	unsigned int udivslot = 0;
1539 
1540 	/*
1541 	 * We don't support modem control lines.
1542 	 */
1543 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1544 	termios->c_cflag |= CLOCAL;
1545 
1546 	/*
1547 	 * Ask the core to calculate the divisor for us.
1548 	 */
1549 
1550 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1551 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1552 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1553 		quot = port->custom_divisor;
1554 	if (IS_ERR(clk))
1555 		return;
1556 
1557 	/* check to see if we need  to change clock source */
1558 
1559 	if (ourport->baudclk != clk) {
1560 		clk_prepare_enable(clk);
1561 
1562 		s3c24xx_serial_setsource(port, clk_sel);
1563 
1564 		if (!IS_ERR(ourport->baudclk)) {
1565 			clk_disable_unprepare(ourport->baudclk);
1566 			ourport->baudclk = ERR_PTR(-EINVAL);
1567 		}
1568 
1569 		ourport->baudclk = clk;
1570 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1571 	}
1572 
1573 	if (ourport->info->has_divslot) {
1574 		unsigned int div = ourport->baudclk_rate / baud;
1575 
1576 		if (cfg->has_fracval) {
1577 			udivslot = (div & 15);
1578 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1579 		} else {
1580 			udivslot = udivslot_table[div & 15];
1581 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1582 				udivslot, div & 15);
1583 		}
1584 	}
1585 
1586 	switch (termios->c_cflag & CSIZE) {
1587 	case CS5:
1588 		dev_dbg(port->dev, "config: 5bits/char\n");
1589 		ulcon = S3C2410_LCON_CS5;
1590 		break;
1591 	case CS6:
1592 		dev_dbg(port->dev, "config: 6bits/char\n");
1593 		ulcon = S3C2410_LCON_CS6;
1594 		break;
1595 	case CS7:
1596 		dev_dbg(port->dev, "config: 7bits/char\n");
1597 		ulcon = S3C2410_LCON_CS7;
1598 		break;
1599 	case CS8:
1600 	default:
1601 		dev_dbg(port->dev, "config: 8bits/char\n");
1602 		ulcon = S3C2410_LCON_CS8;
1603 		break;
1604 	}
1605 
1606 	/* preserve original lcon IR settings */
1607 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1608 
1609 	if (termios->c_cflag & CSTOPB)
1610 		ulcon |= S3C2410_LCON_STOPB;
1611 
1612 	if (termios->c_cflag & PARENB) {
1613 		if (termios->c_cflag & PARODD)
1614 			ulcon |= S3C2410_LCON_PODD;
1615 		else
1616 			ulcon |= S3C2410_LCON_PEVEN;
1617 	} else {
1618 		ulcon |= S3C2410_LCON_PNONE;
1619 	}
1620 
1621 	spin_lock_irqsave(&port->lock, flags);
1622 
1623 	dev_dbg(port->dev,
1624 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1625 		ulcon, quot, udivslot);
1626 
1627 	wr_regl(port, S3C2410_ULCON, ulcon);
1628 	wr_regl(port, S3C2410_UBRDIV, quot);
1629 
1630 	port->status &= ~UPSTAT_AUTOCTS;
1631 
1632 	umcon = rd_regl(port, S3C2410_UMCON);
1633 	if (termios->c_cflag & CRTSCTS) {
1634 		umcon |= S3C2410_UMCOM_AFC;
1635 		/* Disable RTS when RX FIFO contains 63 bytes */
1636 		umcon &= ~S3C2412_UMCON_AFC_8;
1637 		port->status = UPSTAT_AUTOCTS;
1638 	} else {
1639 		umcon &= ~S3C2410_UMCOM_AFC;
1640 	}
1641 	wr_regl(port, S3C2410_UMCON, umcon);
1642 
1643 	if (ourport->info->has_divslot)
1644 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1645 
1646 	dev_dbg(port->dev,
1647 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1648 		rd_regl(port, S3C2410_ULCON),
1649 		rd_regl(port, S3C2410_UCON),
1650 		rd_regl(port, S3C2410_UFCON));
1651 
1652 	/*
1653 	 * Update the per-port timeout.
1654 	 */
1655 	uart_update_timeout(port, termios->c_cflag, baud);
1656 
1657 	/*
1658 	 * Which character status flags are we interested in?
1659 	 */
1660 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1661 	if (termios->c_iflag & INPCK)
1662 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1663 			S3C2410_UERSTAT_PARITY;
1664 	/*
1665 	 * Which character status flags should we ignore?
1666 	 */
1667 	port->ignore_status_mask = 0;
1668 	if (termios->c_iflag & IGNPAR)
1669 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1670 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1671 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1672 
1673 	/*
1674 	 * Ignore all characters if CREAD is not set.
1675 	 */
1676 	if ((termios->c_cflag & CREAD) == 0)
1677 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1678 
1679 	spin_unlock_irqrestore(&port->lock, flags);
1680 }
1681 
1682 static const char *s3c24xx_serial_type(struct uart_port *port)
1683 {
1684 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
1685 
1686 	switch (ourport->info->type) {
1687 	case TYPE_S3C24XX:
1688 		return "S3C24XX";
1689 	case TYPE_S3C6400:
1690 		return "S3C6400/10";
1691 	case TYPE_APPLE_S5L:
1692 		return "APPLE S5L";
1693 	default:
1694 		return NULL;
1695 	}
1696 }
1697 
1698 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1699 {
1700 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1701 
1702 	if (flags & UART_CONFIG_TYPE)
1703 		port->type = info->port_type;
1704 }
1705 
1706 /*
1707  * verify the new serial_struct (for TIOCSSERIAL).
1708  */
1709 static int
1710 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1711 {
1712 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1713 
1714 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1715 		return -EINVAL;
1716 
1717 	return 0;
1718 }
1719 
1720 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1721 
1722 static struct console s3c24xx_serial_console;
1723 
1724 static void __init s3c24xx_serial_register_console(void)
1725 {
1726 	register_console(&s3c24xx_serial_console);
1727 }
1728 
1729 static void s3c24xx_serial_unregister_console(void)
1730 {
1731 	if (console_is_registered(&s3c24xx_serial_console))
1732 		unregister_console(&s3c24xx_serial_console);
1733 }
1734 
1735 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1736 #else
1737 static inline void s3c24xx_serial_register_console(void) { }
1738 static inline void s3c24xx_serial_unregister_console(void) { }
1739 #define S3C24XX_SERIAL_CONSOLE NULL
1740 #endif
1741 
1742 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1743 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1744 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1745 			 unsigned char c);
1746 #endif
1747 
1748 static const struct uart_ops s3c24xx_serial_ops = {
1749 	.pm		= s3c24xx_serial_pm,
1750 	.tx_empty	= s3c24xx_serial_tx_empty,
1751 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1752 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1753 	.stop_tx	= s3c24xx_serial_stop_tx,
1754 	.start_tx	= s3c24xx_serial_start_tx,
1755 	.stop_rx	= s3c24xx_serial_stop_rx,
1756 	.break_ctl	= s3c24xx_serial_break_ctl,
1757 	.startup	= s3c24xx_serial_startup,
1758 	.shutdown	= s3c24xx_serial_shutdown,
1759 	.set_termios	= s3c24xx_serial_set_termios,
1760 	.type		= s3c24xx_serial_type,
1761 	.config_port	= s3c24xx_serial_config_port,
1762 	.verify_port	= s3c24xx_serial_verify_port,
1763 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1764 	.poll_get_char = s3c24xx_serial_get_poll_char,
1765 	.poll_put_char = s3c24xx_serial_put_poll_char,
1766 #endif
1767 };
1768 
1769 static const struct uart_ops s3c64xx_serial_ops = {
1770 	.pm		= s3c24xx_serial_pm,
1771 	.tx_empty	= s3c24xx_serial_tx_empty,
1772 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1773 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1774 	.stop_tx	= s3c24xx_serial_stop_tx,
1775 	.start_tx	= s3c24xx_serial_start_tx,
1776 	.stop_rx	= s3c24xx_serial_stop_rx,
1777 	.break_ctl	= s3c24xx_serial_break_ctl,
1778 	.startup	= s3c64xx_serial_startup,
1779 	.shutdown	= s3c64xx_serial_shutdown,
1780 	.set_termios	= s3c24xx_serial_set_termios,
1781 	.type		= s3c24xx_serial_type,
1782 	.config_port	= s3c24xx_serial_config_port,
1783 	.verify_port	= s3c24xx_serial_verify_port,
1784 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1785 	.poll_get_char = s3c24xx_serial_get_poll_char,
1786 	.poll_put_char = s3c24xx_serial_put_poll_char,
1787 #endif
1788 };
1789 
1790 static const struct uart_ops apple_s5l_serial_ops = {
1791 	.pm		= s3c24xx_serial_pm,
1792 	.tx_empty	= s3c24xx_serial_tx_empty,
1793 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1794 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1795 	.stop_tx	= s3c24xx_serial_stop_tx,
1796 	.start_tx	= s3c24xx_serial_start_tx,
1797 	.stop_rx	= s3c24xx_serial_stop_rx,
1798 	.break_ctl	= s3c24xx_serial_break_ctl,
1799 	.startup	= apple_s5l_serial_startup,
1800 	.shutdown	= apple_s5l_serial_shutdown,
1801 	.set_termios	= s3c24xx_serial_set_termios,
1802 	.type		= s3c24xx_serial_type,
1803 	.config_port	= s3c24xx_serial_config_port,
1804 	.verify_port	= s3c24xx_serial_verify_port,
1805 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1806 	.poll_get_char = s3c24xx_serial_get_poll_char,
1807 	.poll_put_char = s3c24xx_serial_put_poll_char,
1808 #endif
1809 };
1810 
1811 static struct uart_driver s3c24xx_uart_drv = {
1812 	.owner		= THIS_MODULE,
1813 	.driver_name	= "s3c2410_serial",
1814 	.nr		= UART_NR,
1815 	.cons		= S3C24XX_SERIAL_CONSOLE,
1816 	.dev_name	= S3C24XX_SERIAL_NAME,
1817 	.major		= S3C24XX_SERIAL_MAJOR,
1818 	.minor		= S3C24XX_SERIAL_MINOR,
1819 };
1820 
1821 static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
1822 
1823 static void s3c24xx_serial_init_port_default(int index) {
1824 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1825 
1826 	spin_lock_init(&port->lock);
1827 
1828 	port->iotype = UPIO_MEM;
1829 	port->uartclk = 0;
1830 	port->fifosize = 16;
1831 	port->ops = &s3c24xx_serial_ops;
1832 	port->flags = UPF_BOOT_AUTOCONF;
1833 	port->line = index;
1834 }
1835 
1836 /* s3c24xx_serial_resetport
1837  *
1838  * reset the fifos and other the settings.
1839  */
1840 
1841 static void s3c24xx_serial_resetport(struct uart_port *port,
1842 				     const struct s3c2410_uartcfg *cfg)
1843 {
1844 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1845 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1846 
1847 	ucon &= (info->clksel_mask | info->ucon_mask);
1848 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1849 
1850 	/* reset both fifos */
1851 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1852 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1853 
1854 	/* some delay is required after fifo reset */
1855 	udelay(1);
1856 }
1857 
1858 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1859 
1860 static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1861 					     unsigned long val, void *data)
1862 {
1863 	struct s3c24xx_uart_port *port;
1864 	struct uart_port *uport;
1865 
1866 	port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1867 	uport = &port->port;
1868 
1869 	/* check to see if port is enabled */
1870 
1871 	if (port->pm_level != 0)
1872 		return 0;
1873 
1874 	/* try and work out if the baudrate is changing, we can detect
1875 	 * a change in rate, but we do not have support for detecting
1876 	 * a disturbance in the clock-rate over the change.
1877 	 */
1878 
1879 	if (IS_ERR(port->baudclk))
1880 		goto exit;
1881 
1882 	if (port->baudclk_rate == clk_get_rate(port->baudclk))
1883 		goto exit;
1884 
1885 	if (val == CPUFREQ_PRECHANGE) {
1886 		/* we should really shut the port down whilst the
1887 		 * frequency change is in progress.
1888 		 */
1889 
1890 	} else if (val == CPUFREQ_POSTCHANGE) {
1891 		struct ktermios *termios;
1892 		struct tty_struct *tty;
1893 
1894 		if (uport->state == NULL)
1895 			goto exit;
1896 
1897 		tty = uport->state->port.tty;
1898 
1899 		if (tty == NULL)
1900 			goto exit;
1901 
1902 		termios = &tty->termios;
1903 
1904 		if (termios == NULL) {
1905 			dev_warn(uport->dev, "%s: no termios?\n", __func__);
1906 			goto exit;
1907 		}
1908 
1909 		s3c24xx_serial_set_termios(uport, termios, NULL);
1910 	}
1911 
1912 exit:
1913 	return 0;
1914 }
1915 
1916 static inline int
1917 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1918 {
1919 	port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1920 
1921 	return cpufreq_register_notifier(&port->freq_transition,
1922 					 CPUFREQ_TRANSITION_NOTIFIER);
1923 }
1924 
1925 static inline void
1926 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1927 {
1928 	cpufreq_unregister_notifier(&port->freq_transition,
1929 				    CPUFREQ_TRANSITION_NOTIFIER);
1930 }
1931 
1932 #else
1933 static inline int
1934 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1935 {
1936 	return 0;
1937 }
1938 
1939 static inline void
1940 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1941 {
1942 }
1943 #endif
1944 
1945 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1946 {
1947 	struct device *dev = ourport->port.dev;
1948 	const struct s3c24xx_uart_info *info = ourport->info;
1949 	char clk_name[MAX_CLK_NAME_LENGTH];
1950 	unsigned int clk_sel;
1951 	struct clk *clk;
1952 	int clk_num;
1953 	int ret;
1954 
1955 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1956 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1957 		if (!(clk_sel & (1 << clk_num)))
1958 			continue;
1959 
1960 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1961 		clk = clk_get(dev, clk_name);
1962 		if (IS_ERR(clk))
1963 			continue;
1964 
1965 		ret = clk_prepare_enable(clk);
1966 		if (ret) {
1967 			clk_put(clk);
1968 			continue;
1969 		}
1970 
1971 		ourport->baudclk = clk;
1972 		ourport->baudclk_rate = clk_get_rate(clk);
1973 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1974 
1975 		return 0;
1976 	}
1977 
1978 	return -EINVAL;
1979 }
1980 
1981 /* s3c24xx_serial_init_port
1982  *
1983  * initialise a single serial port from the platform device given
1984  */
1985 
1986 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1987 				    struct platform_device *platdev)
1988 {
1989 	struct uart_port *port = &ourport->port;
1990 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1991 	struct resource *res;
1992 	int ret;
1993 
1994 	if (platdev == NULL)
1995 		return -ENODEV;
1996 
1997 	if (port->mapbase != 0)
1998 		return -EINVAL;
1999 
2000 	/* setup info for port */
2001 	port->dev	= &platdev->dev;
2002 
2003 	port->uartclk = 1;
2004 
2005 	if (cfg->uart_flags & UPF_CONS_FLOW) {
2006 		dev_dbg(port->dev, "enabling flow control\n");
2007 		port->flags |= UPF_CONS_FLOW;
2008 	}
2009 
2010 	/* sort our the physical and virtual addresses for each UART */
2011 
2012 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
2013 	if (res == NULL) {
2014 		dev_err(port->dev, "failed to find memory resource for uart\n");
2015 		return -EINVAL;
2016 	}
2017 
2018 	dev_dbg(port->dev, "resource %pR)\n", res);
2019 
2020 	port->membase = devm_ioremap_resource(port->dev, res);
2021 	if (IS_ERR(port->membase)) {
2022 		dev_err(port->dev, "failed to remap controller address\n");
2023 		return -EBUSY;
2024 	}
2025 
2026 	port->mapbase = res->start;
2027 	ret = platform_get_irq(platdev, 0);
2028 	if (ret < 0) {
2029 		port->irq = 0;
2030 	} else {
2031 		port->irq = ret;
2032 		ourport->rx_irq = ret;
2033 		ourport->tx_irq = ret + 1;
2034 	}
2035 
2036 	switch (ourport->info->type) {
2037 	case TYPE_S3C24XX:
2038 		ret = platform_get_irq(platdev, 1);
2039 		if (ret > 0)
2040 			ourport->tx_irq = ret;
2041 		break;
2042 	default:
2043 		break;
2044 	}
2045 
2046 	/*
2047 	 * DMA is currently supported only on DT platforms, if DMA properties
2048 	 * are specified.
2049 	 */
2050 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
2051 						     "dmas", NULL)) {
2052 		ourport->dma = devm_kzalloc(port->dev,
2053 					    sizeof(*ourport->dma),
2054 					    GFP_KERNEL);
2055 		if (!ourport->dma) {
2056 			ret = -ENOMEM;
2057 			goto err;
2058 		}
2059 	}
2060 
2061 	ourport->clk	= clk_get(&platdev->dev, "uart");
2062 	if (IS_ERR(ourport->clk)) {
2063 		pr_err("%s: Controller clock not found\n",
2064 				dev_name(&platdev->dev));
2065 		ret = PTR_ERR(ourport->clk);
2066 		goto err;
2067 	}
2068 
2069 	ret = clk_prepare_enable(ourport->clk);
2070 	if (ret) {
2071 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
2072 		clk_put(ourport->clk);
2073 		goto err;
2074 	}
2075 
2076 	ret = s3c24xx_serial_enable_baudclk(ourport);
2077 	if (ret)
2078 		pr_warn("uart: failed to enable baudclk\n");
2079 
2080 	/* Keep all interrupts masked and cleared */
2081 	switch (ourport->info->type) {
2082 	case TYPE_S3C6400:
2083 		wr_regl(port, S3C64XX_UINTM, 0xf);
2084 		wr_regl(port, S3C64XX_UINTP, 0xf);
2085 		wr_regl(port, S3C64XX_UINTSP, 0xf);
2086 		break;
2087 	case TYPE_APPLE_S5L: {
2088 		unsigned int ucon;
2089 
2090 		ucon = rd_regl(port, S3C2410_UCON);
2091 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2092 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2093 			APPLE_S5L_UCON_RXTO_ENA_MSK);
2094 		wr_regl(port, S3C2410_UCON, ucon);
2095 
2096 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
2097 		break;
2098 	}
2099 	default:
2100 		break;
2101 	}
2102 
2103 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
2104 		&port->mapbase, port->membase, port->irq,
2105 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
2106 
2107 	/* reset the fifos (and setup the uart) */
2108 	s3c24xx_serial_resetport(port, cfg);
2109 
2110 	return 0;
2111 
2112 err:
2113 	port->mapbase = 0;
2114 	return ret;
2115 }
2116 
2117 /* Device driver serial port probe */
2118 
2119 static int probe_index;
2120 
2121 static inline const struct s3c24xx_serial_drv_data *
2122 s3c24xx_get_driver_data(struct platform_device *pdev)
2123 {
2124 	if (dev_of_node(&pdev->dev))
2125 		return of_device_get_match_data(&pdev->dev);
2126 
2127 	return (struct s3c24xx_serial_drv_data *)
2128 			platform_get_device_id(pdev)->driver_data;
2129 }
2130 
2131 static int s3c24xx_serial_probe(struct platform_device *pdev)
2132 {
2133 	struct device_node *np = pdev->dev.of_node;
2134 	struct s3c24xx_uart_port *ourport;
2135 	int index = probe_index;
2136 	int ret, prop = 0;
2137 
2138 	if (np) {
2139 		ret = of_alias_get_id(np, "serial");
2140 		if (ret >= 0)
2141 			index = ret;
2142 	}
2143 
2144 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2145 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2146 		return -EINVAL;
2147 	}
2148 	ourport = &s3c24xx_serial_ports[index];
2149 
2150 	s3c24xx_serial_init_port_default(index);
2151 
2152 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2153 	if (!ourport->drv_data) {
2154 		dev_err(&pdev->dev, "could not find driver data\n");
2155 		return -ENODEV;
2156 	}
2157 
2158 	ourport->baudclk = ERR_PTR(-EINVAL);
2159 	ourport->info = &ourport->drv_data->info;
2160 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2161 			dev_get_platdata(&pdev->dev) :
2162 			&ourport->drv_data->def_cfg;
2163 
2164 	switch (ourport->info->type) {
2165 	case TYPE_S3C24XX:
2166 		ourport->port.ops = &s3c24xx_serial_ops;
2167 		break;
2168 	case TYPE_S3C6400:
2169 		ourport->port.ops = &s3c64xx_serial_ops;
2170 		break;
2171 	case TYPE_APPLE_S5L:
2172 		ourport->port.ops = &apple_s5l_serial_ops;
2173 		break;
2174 	}
2175 
2176 	if (np) {
2177 		of_property_read_u32(np,
2178 			"samsung,uart-fifosize", &ourport->port.fifosize);
2179 
2180 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2181 			switch (prop) {
2182 			case 1:
2183 				ourport->port.iotype = UPIO_MEM;
2184 				break;
2185 			case 4:
2186 				ourport->port.iotype = UPIO_MEM32;
2187 				break;
2188 			default:
2189 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2190 						prop);
2191 				return -EINVAL;
2192 			}
2193 		}
2194 	}
2195 
2196 	if (ourport->drv_data->fifosize[index])
2197 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2198 	else if (ourport->info->fifosize)
2199 		ourport->port.fifosize = ourport->info->fifosize;
2200 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2201 
2202 	/*
2203 	 * DMA transfers must be aligned at least to cache line size,
2204 	 * so find minimal transfer size suitable for DMA mode
2205 	 */
2206 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2207 				    dma_get_cache_alignment());
2208 
2209 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2210 
2211 	ret = s3c24xx_serial_init_port(ourport, pdev);
2212 	if (ret < 0)
2213 		return ret;
2214 
2215 	if (!s3c24xx_uart_drv.state) {
2216 		ret = uart_register_driver(&s3c24xx_uart_drv);
2217 		if (ret < 0) {
2218 			pr_err("Failed to register Samsung UART driver\n");
2219 			return ret;
2220 		}
2221 	}
2222 
2223 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2224 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2225 	platform_set_drvdata(pdev, &ourport->port);
2226 
2227 	/*
2228 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2229 	 * so that a potential re-enablement through the pm-callback overlaps
2230 	 * and keeps the clock enabled in this case.
2231 	 */
2232 	clk_disable_unprepare(ourport->clk);
2233 	if (!IS_ERR(ourport->baudclk))
2234 		clk_disable_unprepare(ourport->baudclk);
2235 
2236 	ret = s3c24xx_serial_cpufreq_register(ourport);
2237 	if (ret < 0)
2238 		dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
2239 
2240 	probe_index++;
2241 
2242 	return 0;
2243 }
2244 
2245 static int s3c24xx_serial_remove(struct platform_device *dev)
2246 {
2247 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2248 
2249 	if (port) {
2250 		s3c24xx_serial_cpufreq_deregister(to_ourport(port));
2251 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2252 	}
2253 
2254 	uart_unregister_driver(&s3c24xx_uart_drv);
2255 
2256 	return 0;
2257 }
2258 
2259 /* UART power management code */
2260 #ifdef CONFIG_PM_SLEEP
2261 static int s3c24xx_serial_suspend(struct device *dev)
2262 {
2263 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2264 
2265 	if (port)
2266 		uart_suspend_port(&s3c24xx_uart_drv, port);
2267 
2268 	return 0;
2269 }
2270 
2271 static int s3c24xx_serial_resume(struct device *dev)
2272 {
2273 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2274 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2275 
2276 	if (port) {
2277 		clk_prepare_enable(ourport->clk);
2278 		if (!IS_ERR(ourport->baudclk))
2279 			clk_prepare_enable(ourport->baudclk);
2280 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2281 		if (!IS_ERR(ourport->baudclk))
2282 			clk_disable_unprepare(ourport->baudclk);
2283 		clk_disable_unprepare(ourport->clk);
2284 
2285 		uart_resume_port(&s3c24xx_uart_drv, port);
2286 	}
2287 
2288 	return 0;
2289 }
2290 
2291 static int s3c24xx_serial_resume_noirq(struct device *dev)
2292 {
2293 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2294 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2295 
2296 	if (port) {
2297 		/* restore IRQ mask */
2298 		switch (ourport->info->type) {
2299 		case TYPE_S3C6400: {
2300 			unsigned int uintm = 0xf;
2301 
2302 			if (ourport->tx_enabled)
2303 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2304 			if (ourport->rx_enabled)
2305 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2306 			clk_prepare_enable(ourport->clk);
2307 			if (!IS_ERR(ourport->baudclk))
2308 				clk_prepare_enable(ourport->baudclk);
2309 			wr_regl(port, S3C64XX_UINTM, uintm);
2310 			if (!IS_ERR(ourport->baudclk))
2311 				clk_disable_unprepare(ourport->baudclk);
2312 			clk_disable_unprepare(ourport->clk);
2313 			break;
2314 		}
2315 		case TYPE_APPLE_S5L: {
2316 			unsigned int ucon;
2317 			int ret;
2318 
2319 			ret = clk_prepare_enable(ourport->clk);
2320 			if (ret) {
2321 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2322 				return ret;
2323 			}
2324 			if (!IS_ERR(ourport->baudclk)) {
2325 				ret = clk_prepare_enable(ourport->baudclk);
2326 				if (ret) {
2327 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2328 					clk_disable_unprepare(ourport->clk);
2329 					return ret;
2330 				}
2331 			}
2332 
2333 			ucon = rd_regl(port, S3C2410_UCON);
2334 
2335 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2336 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2337 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2338 
2339 			if (ourport->tx_enabled)
2340 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2341 			if (ourport->rx_enabled)
2342 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2343 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2344 
2345 			wr_regl(port, S3C2410_UCON, ucon);
2346 
2347 			if (!IS_ERR(ourport->baudclk))
2348 				clk_disable_unprepare(ourport->baudclk);
2349 			clk_disable_unprepare(ourport->clk);
2350 			break;
2351 		}
2352 		default:
2353 			break;
2354 		}
2355 	}
2356 
2357 	return 0;
2358 }
2359 
2360 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2361 	.suspend = s3c24xx_serial_suspend,
2362 	.resume = s3c24xx_serial_resume,
2363 	.resume_noirq = s3c24xx_serial_resume_noirq,
2364 };
2365 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2366 
2367 #else /* !CONFIG_PM_SLEEP */
2368 
2369 #define SERIAL_SAMSUNG_PM_OPS	NULL
2370 #endif /* CONFIG_PM_SLEEP */
2371 
2372 /* Console code */
2373 
2374 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2375 
2376 static struct uart_port *cons_uart;
2377 
2378 static int
2379 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2380 {
2381 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2382 	unsigned long ufstat, utrstat;
2383 
2384 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2385 		/* fifo mode - check amount of data in fifo registers... */
2386 
2387 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2388 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2389 	}
2390 
2391 	/* in non-fifo mode, we go and use the tx buffer empty */
2392 
2393 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2394 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2395 }
2396 
2397 static bool
2398 s3c24xx_port_configured(unsigned int ucon)
2399 {
2400 	/* consider the serial port configured if the tx/rx mode set */
2401 	return (ucon & 0xf) != 0;
2402 }
2403 
2404 #ifdef CONFIG_CONSOLE_POLL
2405 /*
2406  * Console polling routines for writing and reading from the uart while
2407  * in an interrupt or debug context.
2408  */
2409 
2410 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2411 {
2412 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2413 	unsigned int ufstat;
2414 
2415 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2416 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2417 		return NO_POLL_CHAR;
2418 
2419 	return rd_reg(port, S3C2410_URXH);
2420 }
2421 
2422 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2423 		unsigned char c)
2424 {
2425 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2426 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2427 
2428 	/* not possible to xmit on unconfigured port */
2429 	if (!s3c24xx_port_configured(ucon))
2430 		return;
2431 
2432 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2433 		cpu_relax();
2434 	wr_reg(port, S3C2410_UTXH, c);
2435 }
2436 
2437 #endif /* CONFIG_CONSOLE_POLL */
2438 
2439 static void
2440 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2441 {
2442 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2443 
2444 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2445 		cpu_relax();
2446 	wr_reg(port, S3C2410_UTXH, ch);
2447 }
2448 
2449 static void
2450 s3c24xx_serial_console_write(struct console *co, const char *s,
2451 			     unsigned int count)
2452 {
2453 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2454 	unsigned long flags;
2455 	bool locked = true;
2456 
2457 	/* not possible to xmit on unconfigured port */
2458 	if (!s3c24xx_port_configured(ucon))
2459 		return;
2460 
2461 	if (cons_uart->sysrq)
2462 		locked = false;
2463 	else if (oops_in_progress)
2464 		locked = spin_trylock_irqsave(&cons_uart->lock, flags);
2465 	else
2466 		spin_lock_irqsave(&cons_uart->lock, flags);
2467 
2468 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2469 
2470 	if (locked)
2471 		spin_unlock_irqrestore(&cons_uart->lock, flags);
2472 }
2473 
2474 /* Shouldn't be __init, as it can be instantiated from other module */
2475 static void
2476 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2477 			   int *parity, int *bits)
2478 {
2479 	struct clk *clk;
2480 	unsigned int ulcon;
2481 	unsigned int ucon;
2482 	unsigned int ubrdiv;
2483 	unsigned long rate;
2484 	unsigned int clk_sel;
2485 	char clk_name[MAX_CLK_NAME_LENGTH];
2486 
2487 	ulcon  = rd_regl(port, S3C2410_ULCON);
2488 	ucon   = rd_regl(port, S3C2410_UCON);
2489 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2490 
2491 	if (s3c24xx_port_configured(ucon)) {
2492 		switch (ulcon & S3C2410_LCON_CSMASK) {
2493 		case S3C2410_LCON_CS5:
2494 			*bits = 5;
2495 			break;
2496 		case S3C2410_LCON_CS6:
2497 			*bits = 6;
2498 			break;
2499 		case S3C2410_LCON_CS7:
2500 			*bits = 7;
2501 			break;
2502 		case S3C2410_LCON_CS8:
2503 		default:
2504 			*bits = 8;
2505 			break;
2506 		}
2507 
2508 		switch (ulcon & S3C2410_LCON_PMASK) {
2509 		case S3C2410_LCON_PEVEN:
2510 			*parity = 'e';
2511 			break;
2512 
2513 		case S3C2410_LCON_PODD:
2514 			*parity = 'o';
2515 			break;
2516 
2517 		case S3C2410_LCON_PNONE:
2518 		default:
2519 			*parity = 'n';
2520 		}
2521 
2522 		/* now calculate the baud rate */
2523 
2524 		clk_sel = s3c24xx_serial_getsource(port);
2525 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2526 
2527 		clk = clk_get(port->dev, clk_name);
2528 		if (!IS_ERR(clk))
2529 			rate = clk_get_rate(clk);
2530 		else
2531 			rate = 1;
2532 
2533 		*baud = rate / (16 * (ubrdiv + 1));
2534 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2535 	}
2536 }
2537 
2538 /* Shouldn't be __init, as it can be instantiated from other module */
2539 static int
2540 s3c24xx_serial_console_setup(struct console *co, char *options)
2541 {
2542 	struct uart_port *port;
2543 	int baud = 9600;
2544 	int bits = 8;
2545 	int parity = 'n';
2546 	int flow = 'n';
2547 
2548 	/* is this a valid port */
2549 
2550 	if (co->index == -1 || co->index >= UART_NR)
2551 		co->index = 0;
2552 
2553 	port = &s3c24xx_serial_ports[co->index].port;
2554 
2555 	/* is the port configured? */
2556 
2557 	if (port->mapbase == 0x0)
2558 		return -ENODEV;
2559 
2560 	cons_uart = port;
2561 
2562 	/*
2563 	 * Check whether an invalid uart number has been specified, and
2564 	 * if so, search for the first available port that does have
2565 	 * console support.
2566 	 */
2567 	if (options)
2568 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2569 	else
2570 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2571 
2572 	dev_dbg(port->dev, "baud %d\n", baud);
2573 
2574 	return uart_set_options(port, co, baud, parity, bits, flow);
2575 }
2576 
2577 static struct console s3c24xx_serial_console = {
2578 	.name		= S3C24XX_SERIAL_NAME,
2579 	.device		= uart_console_device,
2580 	.flags		= CON_PRINTBUFFER,
2581 	.index		= -1,
2582 	.write		= s3c24xx_serial_console_write,
2583 	.setup		= s3c24xx_serial_console_setup,
2584 	.data		= &s3c24xx_uart_drv,
2585 };
2586 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2587 
2588 #ifdef CONFIG_CPU_S3C2410
2589 static const struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
2590 	.info = {
2591 		.name		= "Samsung S3C2410 UART",
2592 		.type		= TYPE_S3C24XX,
2593 		.port_type	= PORT_S3C2410,
2594 		.fifosize	= 16,
2595 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2596 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2597 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2598 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2599 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2600 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2601 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2602 		.num_clks	= 2,
2603 		.clksel_mask	= S3C2410_UCON_CLKMASK,
2604 		.clksel_shift	= S3C2410_UCON_CLKSHIFT,
2605 	},
2606 	.def_cfg = {
2607 		.ucon		= S3C2410_UCON_DEFAULT,
2608 		.ufcon		= S3C2410_UFCON_DEFAULT,
2609 	},
2610 };
2611 #define S3C2410_SERIAL_DRV_DATA (&s3c2410_serial_drv_data)
2612 #else
2613 #define S3C2410_SERIAL_DRV_DATA NULL
2614 #endif
2615 
2616 #ifdef CONFIG_CPU_S3C2412
2617 static const struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
2618 	.info = {
2619 		.name		= "Samsung S3C2412 UART",
2620 		.type		= TYPE_S3C24XX,
2621 		.port_type	= PORT_S3C2412,
2622 		.fifosize	= 64,
2623 		.has_divslot	= 1,
2624 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2625 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2626 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2627 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2628 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2629 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2630 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2631 		.num_clks	= 4,
2632 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2633 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2634 	},
2635 	.def_cfg = {
2636 		.ucon		= S3C2410_UCON_DEFAULT,
2637 		.ufcon		= S3C2410_UFCON_DEFAULT,
2638 	},
2639 };
2640 #define S3C2412_SERIAL_DRV_DATA (&s3c2412_serial_drv_data)
2641 #else
2642 #define S3C2412_SERIAL_DRV_DATA NULL
2643 #endif
2644 
2645 #if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
2646 	defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
2647 static const struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
2648 	.info = {
2649 		.name		= "Samsung S3C2440 UART",
2650 		.type		= TYPE_S3C24XX,
2651 		.port_type	= PORT_S3C2440,
2652 		.fifosize	= 64,
2653 		.has_divslot	= 1,
2654 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2655 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2656 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2657 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2658 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2659 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2660 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2661 		.num_clks	= 4,
2662 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2663 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2664 		.ucon_mask	= S3C2440_UCON0_DIVMASK,
2665 	},
2666 	.def_cfg = {
2667 		.ucon		= S3C2410_UCON_DEFAULT,
2668 		.ufcon		= S3C2410_UFCON_DEFAULT,
2669 	},
2670 };
2671 #define S3C2440_SERIAL_DRV_DATA (&s3c2440_serial_drv_data)
2672 #else
2673 #define S3C2440_SERIAL_DRV_DATA NULL
2674 #endif
2675 
2676 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2677 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2678 	.info = {
2679 		.name		= "Samsung S3C6400 UART",
2680 		.type		= TYPE_S3C6400,
2681 		.port_type	= PORT_S3C6400,
2682 		.fifosize	= 64,
2683 		.has_divslot	= 1,
2684 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2685 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2686 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2687 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2688 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2689 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2690 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2691 		.num_clks	= 4,
2692 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2693 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2694 	},
2695 	.def_cfg = {
2696 		.ucon		= S3C2410_UCON_DEFAULT,
2697 		.ufcon		= S3C2410_UFCON_DEFAULT,
2698 	},
2699 };
2700 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2701 #else
2702 #define S3C6400_SERIAL_DRV_DATA NULL
2703 #endif
2704 
2705 #ifdef CONFIG_CPU_S5PV210
2706 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2707 	.info = {
2708 		.name		= "Samsung S5PV210 UART",
2709 		.type		= TYPE_S3C6400,
2710 		.port_type	= PORT_S3C6400,
2711 		.has_divslot	= 1,
2712 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2713 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2714 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2715 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2716 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2717 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2718 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2719 		.num_clks	= 2,
2720 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2721 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2722 	},
2723 	.def_cfg = {
2724 		.ucon		= S5PV210_UCON_DEFAULT,
2725 		.ufcon		= S5PV210_UFCON_DEFAULT,
2726 	},
2727 	.fifosize = { 256, 64, 16, 16 },
2728 };
2729 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2730 #else
2731 #define S5PV210_SERIAL_DRV_DATA	NULL
2732 #endif
2733 
2734 #if defined(CONFIG_ARCH_EXYNOS)
2735 #define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
2736 	.info = {						\
2737 		.name		= "Samsung Exynos UART",	\
2738 		.type		= TYPE_S3C6400,			\
2739 		.port_type	= PORT_S3C6400,			\
2740 		.has_divslot	= 1,				\
2741 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2742 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2743 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2744 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2745 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2746 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2747 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2748 		.num_clks	= 1,				\
2749 		.clksel_mask	= 0,				\
2750 		.clksel_shift	= 0,				\
2751 	},							\
2752 	.def_cfg = {						\
2753 		.ucon		= S5PV210_UCON_DEFAULT,		\
2754 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2755 		.has_fracval	= 1,				\
2756 	}							\
2757 
2758 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2759 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2760 	.fifosize = { 256, 64, 16, 16 },
2761 };
2762 
2763 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2764 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2765 	.fifosize = { 64, 256, 16, 256 },
2766 };
2767 
2768 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2769 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2770 	.fifosize = { 256, 64, 64, 64 },
2771 };
2772 
2773 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2774 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2775 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2776 
2777 #else
2778 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2779 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2780 #define EXYNOS850_SERIAL_DRV_DATA NULL
2781 #endif
2782 
2783 #ifdef CONFIG_ARCH_APPLE
2784 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2785 	.info = {
2786 		.name		= "Apple S5L UART",
2787 		.type		= TYPE_APPLE_S5L,
2788 		.port_type	= PORT_8250,
2789 		.fifosize	= 16,
2790 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2791 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2792 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2793 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2794 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2795 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2796 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2797 		.num_clks	= 1,
2798 		.clksel_mask	= 0,
2799 		.clksel_shift	= 0,
2800 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2801 	},
2802 	.def_cfg = {
2803 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2804 		.ufcon		= S3C2410_UFCON_DEFAULT,
2805 	},
2806 };
2807 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2808 #else
2809 #define S5L_SERIAL_DRV_DATA NULL
2810 #endif
2811 
2812 #if defined(CONFIG_ARCH_ARTPEC)
2813 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2814 	.info = {
2815 		.name		= "Axis ARTPEC-8 UART",
2816 		.type		= TYPE_S3C6400,
2817 		.port_type	= PORT_S3C6400,
2818 		.fifosize	= 64,
2819 		.has_divslot	= 1,
2820 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2821 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2822 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2823 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2824 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2825 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2826 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2827 		.num_clks	= 1,
2828 		.clksel_mask	= 0,
2829 		.clksel_shift	= 0,
2830 	},
2831 	.def_cfg = {
2832 		.ucon		= S5PV210_UCON_DEFAULT,
2833 		.ufcon		= S5PV210_UFCON_DEFAULT,
2834 		.has_fracval	= 1,
2835 	}
2836 };
2837 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2838 #else
2839 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2840 #endif
2841 
2842 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2843 	{
2844 		.name		= "s3c2410-uart",
2845 		.driver_data	= (kernel_ulong_t)S3C2410_SERIAL_DRV_DATA,
2846 	}, {
2847 		.name		= "s3c2412-uart",
2848 		.driver_data	= (kernel_ulong_t)S3C2412_SERIAL_DRV_DATA,
2849 	}, {
2850 		.name		= "s3c2440-uart",
2851 		.driver_data	= (kernel_ulong_t)S3C2440_SERIAL_DRV_DATA,
2852 	}, {
2853 		.name		= "s3c6400-uart",
2854 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2855 	}, {
2856 		.name		= "s5pv210-uart",
2857 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2858 	}, {
2859 		.name		= "exynos4210-uart",
2860 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2861 	}, {
2862 		.name		= "exynos5433-uart",
2863 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2864 	}, {
2865 		.name		= "s5l-uart",
2866 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2867 	}, {
2868 		.name		= "exynos850-uart",
2869 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2870 	}, {
2871 		.name		= "artpec8-uart",
2872 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2873 	},
2874 	{ },
2875 };
2876 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2877 
2878 #ifdef CONFIG_OF
2879 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2880 	{ .compatible = "samsung,s3c2410-uart",
2881 		.data = S3C2410_SERIAL_DRV_DATA },
2882 	{ .compatible = "samsung,s3c2412-uart",
2883 		.data = S3C2412_SERIAL_DRV_DATA },
2884 	{ .compatible = "samsung,s3c2440-uart",
2885 		.data = S3C2440_SERIAL_DRV_DATA },
2886 	{ .compatible = "samsung,s3c6400-uart",
2887 		.data = S3C6400_SERIAL_DRV_DATA },
2888 	{ .compatible = "samsung,s5pv210-uart",
2889 		.data = S5PV210_SERIAL_DRV_DATA },
2890 	{ .compatible = "samsung,exynos4210-uart",
2891 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2892 	{ .compatible = "samsung,exynos5433-uart",
2893 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2894 	{ .compatible = "apple,s5l-uart",
2895 		.data = S5L_SERIAL_DRV_DATA },
2896 	{ .compatible = "samsung,exynos850-uart",
2897 		.data = EXYNOS850_SERIAL_DRV_DATA },
2898 	{ .compatible = "axis,artpec8-uart",
2899 		.data = ARTPEC8_SERIAL_DRV_DATA },
2900 	{},
2901 };
2902 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2903 #endif
2904 
2905 static struct platform_driver samsung_serial_driver = {
2906 	.probe		= s3c24xx_serial_probe,
2907 	.remove		= s3c24xx_serial_remove,
2908 	.id_table	= s3c24xx_serial_driver_ids,
2909 	.driver		= {
2910 		.name	= "samsung-uart",
2911 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2912 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2913 	},
2914 };
2915 
2916 static int __init samsung_serial_init(void)
2917 {
2918 	int ret;
2919 
2920 	s3c24xx_serial_register_console();
2921 
2922 	ret = platform_driver_register(&samsung_serial_driver);
2923 	if (ret) {
2924 		s3c24xx_serial_unregister_console();
2925 		return ret;
2926 	}
2927 
2928 	return 0;
2929 }
2930 
2931 static void __exit samsung_serial_exit(void)
2932 {
2933 	platform_driver_unregister(&samsung_serial_driver);
2934 	s3c24xx_serial_unregister_console();
2935 }
2936 
2937 module_init(samsung_serial_init);
2938 module_exit(samsung_serial_exit);
2939 
2940 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2941 /*
2942  * Early console.
2943  */
2944 
2945 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2946 {
2947 	switch (port->iotype) {
2948 	case UPIO_MEM:
2949 		writeb(val, portaddr(port, reg));
2950 		break;
2951 	case UPIO_MEM32:
2952 		writel(val, portaddr(port, reg));
2953 		break;
2954 	}
2955 }
2956 
2957 struct samsung_early_console_data {
2958 	u32 txfull_mask;
2959 	u32 rxfifo_mask;
2960 };
2961 
2962 static void samsung_early_busyuart(const struct uart_port *port)
2963 {
2964 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2965 		;
2966 }
2967 
2968 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2969 {
2970 	const struct samsung_early_console_data *data = port->private_data;
2971 
2972 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2973 		;
2974 }
2975 
2976 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2977 {
2978 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2979 		samsung_early_busyuart_fifo(port);
2980 	else
2981 		samsung_early_busyuart(port);
2982 
2983 	wr_reg_barrier(port, S3C2410_UTXH, c);
2984 }
2985 
2986 static void samsung_early_write(struct console *con, const char *s,
2987 				unsigned int n)
2988 {
2989 	struct earlycon_device *dev = con->data;
2990 
2991 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2992 }
2993 
2994 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2995 {
2996 	struct earlycon_device *dev = con->data;
2997 	const struct samsung_early_console_data *data = dev->port.private_data;
2998 	int ch, ufstat, num_read = 0;
2999 
3000 	while (num_read < n) {
3001 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
3002 		if (!(ufstat & data->rxfifo_mask))
3003 			break;
3004 		ch = rd_reg(&dev->port, S3C2410_URXH);
3005 		if (ch == NO_POLL_CHAR)
3006 			break;
3007 
3008 		s[num_read++] = ch;
3009 	}
3010 
3011 	return num_read;
3012 }
3013 
3014 static int __init samsung_early_console_setup(struct earlycon_device *device,
3015 					      const char *opt)
3016 {
3017 	if (!device->port.membase)
3018 		return -ENODEV;
3019 
3020 	device->con->write = samsung_early_write;
3021 	device->con->read = samsung_early_read;
3022 	return 0;
3023 }
3024 
3025 /* S3C2410 */
3026 static struct samsung_early_console_data s3c2410_early_console_data = {
3027 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
3028 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
3029 };
3030 
3031 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
3032 					      const char *opt)
3033 {
3034 	device->port.private_data = &s3c2410_early_console_data;
3035 	return samsung_early_console_setup(device, opt);
3036 }
3037 
3038 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
3039 			s3c2410_early_console_setup);
3040 
3041 /* S3C2412, S3C2440, S3C64xx */
3042 static struct samsung_early_console_data s3c2440_early_console_data = {
3043 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
3044 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
3045 };
3046 
3047 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
3048 					      const char *opt)
3049 {
3050 	device->port.private_data = &s3c2440_early_console_data;
3051 	return samsung_early_console_setup(device, opt);
3052 }
3053 
3054 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
3055 			s3c2440_early_console_setup);
3056 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
3057 			s3c2440_early_console_setup);
3058 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
3059 			s3c2440_early_console_setup);
3060 
3061 /* S5PV210, Exynos */
3062 static struct samsung_early_console_data s5pv210_early_console_data = {
3063 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
3064 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
3065 };
3066 
3067 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
3068 					      const char *opt)
3069 {
3070 	device->port.private_data = &s5pv210_early_console_data;
3071 	return samsung_early_console_setup(device, opt);
3072 }
3073 
3074 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
3075 			s5pv210_early_console_setup);
3076 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
3077 			s5pv210_early_console_setup);
3078 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
3079 			s5pv210_early_console_setup);
3080 
3081 /* Apple S5L */
3082 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
3083 						const char *opt)
3084 {
3085 	/* Close enough to S3C2410 for earlycon... */
3086 	device->port.private_data = &s3c2410_early_console_data;
3087 
3088 #ifdef CONFIG_ARM64
3089 	/* ... but we need to override the existing fixmap entry as nGnRnE */
3090 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
3091 		     __pgprot(PROT_DEVICE_nGnRnE));
3092 #endif
3093 	return samsung_early_console_setup(device, opt);
3094 }
3095 
3096 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
3097 #endif
3098 
3099 MODULE_ALIAS("platform:samsung-uart");
3100 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
3101 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
3102 MODULE_LICENSE("GPL v2");
3103