xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision 887069f4)
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 #define S3C24XX_TX_PIO			1
52 #define S3C24XX_TX_DMA			2
53 #define S3C24XX_RX_PIO			1
54 #define S3C24XX_RX_DMA			2
55 
56 /* flag to ignore all characters coming in */
57 #define RXSTAT_DUMMY_READ (0x10000000)
58 
59 enum s3c24xx_port_type {
60 	TYPE_S3C24XX,
61 	TYPE_S3C6400,
62 	TYPE_APPLE_S5L,
63 };
64 
65 struct s3c24xx_uart_info {
66 	char			*name;
67 	enum s3c24xx_port_type	type;
68 	unsigned int		has_usi;
69 	unsigned int		port_type;
70 	unsigned int		fifosize;
71 	unsigned long		rx_fifomask;
72 	unsigned long		rx_fifoshift;
73 	unsigned long		rx_fifofull;
74 	unsigned long		tx_fifomask;
75 	unsigned long		tx_fifoshift;
76 	unsigned long		tx_fifofull;
77 	unsigned int		def_clk_sel;
78 	unsigned long		num_clks;
79 	unsigned long		clksel_mask;
80 	unsigned long		clksel_shift;
81 	unsigned long		ucon_mask;
82 
83 	/* uart port features */
84 
85 	unsigned int		has_divslot:1;
86 };
87 
88 struct s3c24xx_serial_drv_data {
89 	struct s3c24xx_uart_info	*info;
90 	struct s3c2410_uartcfg		*def_cfg;
91 	unsigned int			fifosize[CONFIG_SERIAL_SAMSUNG_UARTS];
92 };
93 
94 struct s3c24xx_uart_dma {
95 	unsigned int			rx_chan_id;
96 	unsigned int			tx_chan_id;
97 
98 	struct dma_slave_config		rx_conf;
99 	struct dma_slave_config		tx_conf;
100 
101 	struct dma_chan			*rx_chan;
102 	struct dma_chan			*tx_chan;
103 
104 	dma_addr_t			rx_addr;
105 	dma_addr_t			tx_addr;
106 
107 	dma_cookie_t			rx_cookie;
108 	dma_cookie_t			tx_cookie;
109 
110 	char				*rx_buf;
111 
112 	dma_addr_t			tx_transfer_addr;
113 
114 	size_t				rx_size;
115 	size_t				tx_size;
116 
117 	struct dma_async_tx_descriptor	*tx_desc;
118 	struct dma_async_tx_descriptor	*rx_desc;
119 
120 	int				tx_bytes_requested;
121 	int				rx_bytes_requested;
122 };
123 
124 struct s3c24xx_uart_port {
125 	unsigned char			rx_claimed;
126 	unsigned char			tx_claimed;
127 	unsigned char			rx_enabled;
128 	unsigned char			tx_enabled;
129 	unsigned int			pm_level;
130 	unsigned long			baudclk_rate;
131 	unsigned int			min_dma_size;
132 
133 	unsigned int			rx_irq;
134 	unsigned int			tx_irq;
135 
136 	unsigned int			tx_in_progress;
137 	unsigned int			tx_mode;
138 	unsigned int			rx_mode;
139 
140 	struct s3c24xx_uart_info	*info;
141 	struct clk			*clk;
142 	struct clk			*baudclk;
143 	struct uart_port		port;
144 	struct s3c24xx_serial_drv_data	*drv_data;
145 
146 	/* reference to platform data */
147 	struct s3c2410_uartcfg		*cfg;
148 
149 	struct s3c24xx_uart_dma		*dma;
150 
151 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
152 	struct notifier_block		freq_transition;
153 #endif
154 };
155 
156 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
157 
158 /* conversion functions */
159 
160 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
161 
162 /* register access controls */
163 
164 #define portaddr(port, reg) ((port)->membase + (reg))
165 #define portaddrl(port, reg) \
166 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
167 
168 static u32 rd_reg(struct uart_port *port, u32 reg)
169 {
170 	switch (port->iotype) {
171 	case UPIO_MEM:
172 		return readb_relaxed(portaddr(port, reg));
173 	case UPIO_MEM32:
174 		return readl_relaxed(portaddr(port, reg));
175 	default:
176 		return 0;
177 	}
178 	return 0;
179 }
180 
181 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
182 
183 static void wr_reg(struct uart_port *port, u32 reg, u32 val)
184 {
185 	switch (port->iotype) {
186 	case UPIO_MEM:
187 		writeb_relaxed(val, portaddr(port, reg));
188 		break;
189 	case UPIO_MEM32:
190 		writel_relaxed(val, portaddr(port, reg));
191 		break;
192 	}
193 }
194 
195 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
196 
197 /* Byte-order aware bit setting/clearing functions. */
198 
199 static inline void s3c24xx_set_bit(struct uart_port *port, int idx,
200 				   unsigned int reg)
201 {
202 	unsigned long flags;
203 	u32 val;
204 
205 	local_irq_save(flags);
206 	val = rd_regl(port, reg);
207 	val |= (1 << idx);
208 	wr_regl(port, reg, val);
209 	local_irq_restore(flags);
210 }
211 
212 static inline void s3c24xx_clear_bit(struct uart_port *port, int idx,
213 				     unsigned int reg)
214 {
215 	unsigned long flags;
216 	u32 val;
217 
218 	local_irq_save(flags);
219 	val = rd_regl(port, reg);
220 	val &= ~(1 << idx);
221 	wr_regl(port, reg, val);
222 	local_irq_restore(flags);
223 }
224 
225 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
226 {
227 	return container_of(port, struct s3c24xx_uart_port, port);
228 }
229 
230 /* translate a port to the device name */
231 
232 static inline const char *s3c24xx_serial_portname(struct uart_port *port)
233 {
234 	return to_platform_device(port->dev)->name;
235 }
236 
237 static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
238 {
239 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
240 }
241 
242 static void s3c24xx_serial_rx_enable(struct uart_port *port)
243 {
244 	struct s3c24xx_uart_port *ourport = to_ourport(port);
245 	unsigned long flags;
246 	unsigned int ucon, ufcon;
247 	int count = 10000;
248 
249 	spin_lock_irqsave(&port->lock, flags);
250 
251 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
252 		udelay(100);
253 
254 	ufcon = rd_regl(port, S3C2410_UFCON);
255 	ufcon |= S3C2410_UFCON_RESETRX;
256 	wr_regl(port, S3C2410_UFCON, ufcon);
257 
258 	ucon = rd_regl(port, S3C2410_UCON);
259 	ucon |= S3C2410_UCON_RXIRQMODE;
260 	wr_regl(port, S3C2410_UCON, ucon);
261 
262 	ourport->rx_enabled = 1;
263 	spin_unlock_irqrestore(&port->lock, flags);
264 }
265 
266 static void s3c24xx_serial_rx_disable(struct uart_port *port)
267 {
268 	struct s3c24xx_uart_port *ourport = to_ourport(port);
269 	unsigned long flags;
270 	unsigned int ucon;
271 
272 	spin_lock_irqsave(&port->lock, flags);
273 
274 	ucon = rd_regl(port, S3C2410_UCON);
275 	ucon &= ~S3C2410_UCON_RXIRQMODE;
276 	wr_regl(port, S3C2410_UCON, ucon);
277 
278 	ourport->rx_enabled = 0;
279 	spin_unlock_irqrestore(&port->lock, flags);
280 }
281 
282 static void s3c24xx_serial_stop_tx(struct uart_port *port)
283 {
284 	struct s3c24xx_uart_port *ourport = to_ourport(port);
285 	struct s3c24xx_uart_dma *dma = ourport->dma;
286 	struct circ_buf *xmit = &port->state->xmit;
287 	struct dma_tx_state state;
288 	int count;
289 
290 	if (!ourport->tx_enabled)
291 		return;
292 
293 	switch (ourport->info->type) {
294 	case TYPE_S3C6400:
295 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
296 		break;
297 	case TYPE_APPLE_S5L:
298 		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
299 		break;
300 	default:
301 		disable_irq_nosync(ourport->tx_irq);
302 		break;
303 	}
304 
305 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
306 		dmaengine_pause(dma->tx_chan);
307 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
308 		dmaengine_terminate_all(dma->tx_chan);
309 		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
310 					dma->tx_transfer_addr, dma->tx_size,
311 					DMA_TO_DEVICE);
312 		async_tx_ack(dma->tx_desc);
313 		count = dma->tx_bytes_requested - state.residue;
314 		xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
315 		port->icount.tx += count;
316 	}
317 
318 	ourport->tx_enabled = 0;
319 	ourport->tx_in_progress = 0;
320 
321 	if (port->flags & UPF_CONS_FLOW)
322 		s3c24xx_serial_rx_enable(port);
323 
324 	ourport->tx_mode = 0;
325 }
326 
327 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
328 
329 static void s3c24xx_serial_tx_dma_complete(void *args)
330 {
331 	struct s3c24xx_uart_port *ourport = args;
332 	struct uart_port *port = &ourport->port;
333 	struct circ_buf *xmit = &port->state->xmit;
334 	struct s3c24xx_uart_dma *dma = ourport->dma;
335 	struct dma_tx_state state;
336 	unsigned long flags;
337 	int count;
338 
339 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
340 	count = dma->tx_bytes_requested - state.residue;
341 	async_tx_ack(dma->tx_desc);
342 
343 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
344 				dma->tx_transfer_addr, dma->tx_size,
345 				DMA_TO_DEVICE);
346 
347 	spin_lock_irqsave(&port->lock, flags);
348 
349 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
350 	port->icount.tx += count;
351 	ourport->tx_in_progress = 0;
352 
353 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
354 		uart_write_wakeup(port);
355 
356 	s3c24xx_serial_start_next_tx(ourport);
357 	spin_unlock_irqrestore(&port->lock, flags);
358 }
359 
360 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
361 {
362 	struct uart_port *port = &ourport->port;
363 	u32 ucon;
364 
365 	/* Mask Tx interrupt */
366 	switch (ourport->info->type) {
367 	case TYPE_S3C6400:
368 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
369 		break;
370 	case TYPE_APPLE_S5L:
371 		WARN_ON(1); // No DMA
372 		break;
373 	default:
374 		disable_irq_nosync(ourport->tx_irq);
375 		break;
376 	}
377 
378 	/* Enable tx dma mode */
379 	ucon = rd_regl(port, S3C2410_UCON);
380 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
381 	ucon |= (dma_get_cache_alignment() >= 16) ?
382 		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
383 	ucon |= S3C64XX_UCON_TXMODE_DMA;
384 	wr_regl(port,  S3C2410_UCON, ucon);
385 
386 	ourport->tx_mode = S3C24XX_TX_DMA;
387 }
388 
389 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
390 {
391 	struct uart_port *port = &ourport->port;
392 	u32 ucon, ufcon;
393 
394 	/* Set ufcon txtrig */
395 	ourport->tx_in_progress = S3C24XX_TX_PIO;
396 	ufcon = rd_regl(port, S3C2410_UFCON);
397 	wr_regl(port,  S3C2410_UFCON, ufcon);
398 
399 	/* Enable tx pio mode */
400 	ucon = rd_regl(port, S3C2410_UCON);
401 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
402 	ucon |= S3C64XX_UCON_TXMODE_CPU;
403 	wr_regl(port,  S3C2410_UCON, ucon);
404 
405 	/* Unmask Tx interrupt */
406 	switch (ourport->info->type) {
407 	case TYPE_S3C6400:
408 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
409 				  S3C64XX_UINTM);
410 		break;
411 	case TYPE_APPLE_S5L:
412 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
413 		wr_regl(port, S3C2410_UCON, ucon);
414 		break;
415 	default:
416 		enable_irq(ourport->tx_irq);
417 		break;
418 	}
419 
420 	ourport->tx_mode = S3C24XX_TX_PIO;
421 
422 	/*
423 	 * The Apple version only has edge triggered TX IRQs, so we need
424 	 * to kick off the process by sending some characters here.
425 	 */
426 	if (ourport->info->type == TYPE_APPLE_S5L)
427 		s3c24xx_serial_tx_chars(ourport);
428 }
429 
430 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
431 {
432 	if (ourport->tx_mode != S3C24XX_TX_PIO)
433 		enable_tx_pio(ourport);
434 }
435 
436 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
437 				      unsigned int count)
438 {
439 	struct uart_port *port = &ourport->port;
440 	struct circ_buf *xmit = &port->state->xmit;
441 	struct s3c24xx_uart_dma *dma = ourport->dma;
442 
443 	if (ourport->tx_mode != S3C24XX_TX_DMA)
444 		enable_tx_dma(ourport);
445 
446 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
447 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
448 
449 	dma_sync_single_for_device(dma->tx_chan->device->dev,
450 				   dma->tx_transfer_addr, dma->tx_size,
451 				   DMA_TO_DEVICE);
452 
453 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
454 				dma->tx_transfer_addr, dma->tx_size,
455 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
456 	if (!dma->tx_desc) {
457 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
458 		return -EIO;
459 	}
460 
461 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
462 	dma->tx_desc->callback_param = ourport;
463 	dma->tx_bytes_requested = dma->tx_size;
464 
465 	ourport->tx_in_progress = S3C24XX_TX_DMA;
466 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
467 	dma_async_issue_pending(dma->tx_chan);
468 	return 0;
469 }
470 
471 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
472 {
473 	struct uart_port *port = &ourport->port;
474 	struct circ_buf *xmit = &port->state->xmit;
475 	unsigned long count;
476 
477 	/* Get data size up to the end of buffer */
478 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
479 
480 	if (!count) {
481 		s3c24xx_serial_stop_tx(port);
482 		return;
483 	}
484 
485 	if (!ourport->dma || !ourport->dma->tx_chan ||
486 	    count < ourport->min_dma_size ||
487 	    xmit->tail & (dma_get_cache_alignment() - 1))
488 		s3c24xx_serial_start_tx_pio(ourport);
489 	else
490 		s3c24xx_serial_start_tx_dma(ourport, count);
491 }
492 
493 static void s3c24xx_serial_start_tx(struct uart_port *port)
494 {
495 	struct s3c24xx_uart_port *ourport = to_ourport(port);
496 	struct circ_buf *xmit = &port->state->xmit;
497 
498 	if (!ourport->tx_enabled) {
499 		if (port->flags & UPF_CONS_FLOW)
500 			s3c24xx_serial_rx_disable(port);
501 
502 		ourport->tx_enabled = 1;
503 		if (!ourport->dma || !ourport->dma->tx_chan)
504 			s3c24xx_serial_start_tx_pio(ourport);
505 	}
506 
507 	if (ourport->dma && ourport->dma->tx_chan) {
508 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
509 			s3c24xx_serial_start_next_tx(ourport);
510 	}
511 }
512 
513 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
514 		struct tty_port *tty, int count)
515 {
516 	struct s3c24xx_uart_dma *dma = ourport->dma;
517 	int copied;
518 
519 	if (!count)
520 		return;
521 
522 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
523 				dma->rx_size, DMA_FROM_DEVICE);
524 
525 	ourport->port.icount.rx += count;
526 	if (!tty) {
527 		dev_err(ourport->port.dev, "No tty port\n");
528 		return;
529 	}
530 	copied = tty_insert_flip_string(tty,
531 			((unsigned char *)(ourport->dma->rx_buf)), count);
532 	if (copied != count) {
533 		WARN_ON(1);
534 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
535 	}
536 }
537 
538 static void s3c24xx_serial_stop_rx(struct uart_port *port)
539 {
540 	struct s3c24xx_uart_port *ourport = to_ourport(port);
541 	struct s3c24xx_uart_dma *dma = ourport->dma;
542 	struct tty_port *t = &port->state->port;
543 	struct dma_tx_state state;
544 	enum dma_status dma_status;
545 	unsigned int received;
546 
547 	if (ourport->rx_enabled) {
548 		dev_dbg(port->dev, "stopping rx\n");
549 		switch (ourport->info->type) {
550 		case TYPE_S3C6400:
551 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
552 					S3C64XX_UINTM);
553 			break;
554 		case TYPE_APPLE_S5L:
555 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
556 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
557 			break;
558 		default:
559 			disable_irq_nosync(ourport->rx_irq);
560 			break;
561 		}
562 		ourport->rx_enabled = 0;
563 	}
564 	if (dma && dma->rx_chan) {
565 		dmaengine_pause(dma->tx_chan);
566 		dma_status = dmaengine_tx_status(dma->rx_chan,
567 				dma->rx_cookie, &state);
568 		if (dma_status == DMA_IN_PROGRESS ||
569 			dma_status == DMA_PAUSED) {
570 			received = dma->rx_bytes_requested - state.residue;
571 			dmaengine_terminate_all(dma->rx_chan);
572 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
573 		}
574 	}
575 }
576 
577 static inline struct s3c24xx_uart_info
578 	*s3c24xx_port_to_info(struct uart_port *port)
579 {
580 	return to_ourport(port)->info;
581 }
582 
583 static inline struct s3c2410_uartcfg
584 	*s3c24xx_port_to_cfg(struct uart_port *port)
585 {
586 	struct s3c24xx_uart_port *ourport;
587 
588 	if (port->dev == NULL)
589 		return NULL;
590 
591 	ourport = container_of(port, struct s3c24xx_uart_port, port);
592 	return ourport->cfg;
593 }
594 
595 static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
596 				     unsigned long ufstat)
597 {
598 	struct s3c24xx_uart_info *info = ourport->info;
599 
600 	if (ufstat & info->rx_fifofull)
601 		return ourport->port.fifosize;
602 
603 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
604 }
605 
606 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
607 static void s3c24xx_serial_rx_dma_complete(void *args)
608 {
609 	struct s3c24xx_uart_port *ourport = args;
610 	struct uart_port *port = &ourport->port;
611 
612 	struct s3c24xx_uart_dma *dma = ourport->dma;
613 	struct tty_port *t = &port->state->port;
614 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
615 
616 	struct dma_tx_state state;
617 	unsigned long flags;
618 	int received;
619 
620 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
621 	received  = dma->rx_bytes_requested - state.residue;
622 	async_tx_ack(dma->rx_desc);
623 
624 	spin_lock_irqsave(&port->lock, flags);
625 
626 	if (received)
627 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
628 
629 	if (tty) {
630 		tty_flip_buffer_push(t);
631 		tty_kref_put(tty);
632 	}
633 
634 	s3c64xx_start_rx_dma(ourport);
635 
636 	spin_unlock_irqrestore(&port->lock, flags);
637 }
638 
639 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
640 {
641 	struct s3c24xx_uart_dma *dma = ourport->dma;
642 
643 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
644 				   dma->rx_size, DMA_FROM_DEVICE);
645 
646 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
647 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
648 				DMA_PREP_INTERRUPT);
649 	if (!dma->rx_desc) {
650 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
651 		return;
652 	}
653 
654 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
655 	dma->rx_desc->callback_param = ourport;
656 	dma->rx_bytes_requested = dma->rx_size;
657 
658 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
659 	dma_async_issue_pending(dma->rx_chan);
660 }
661 
662 /* ? - where has parity gone?? */
663 #define S3C2410_UERSTAT_PARITY (0x1000)
664 
665 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
666 {
667 	struct uart_port *port = &ourport->port;
668 	unsigned int ucon;
669 
670 	/* set Rx mode to DMA mode */
671 	ucon = rd_regl(port, S3C2410_UCON);
672 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
673 			S3C64XX_UCON_TIMEOUT_MASK |
674 			S3C64XX_UCON_EMPTYINT_EN |
675 			S3C64XX_UCON_DMASUS_EN |
676 			S3C64XX_UCON_TIMEOUT_EN |
677 			S3C64XX_UCON_RXMODE_MASK);
678 	ucon |= S3C64XX_UCON_RXBURST_16 |
679 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
680 			S3C64XX_UCON_EMPTYINT_EN |
681 			S3C64XX_UCON_TIMEOUT_EN |
682 			S3C64XX_UCON_RXMODE_DMA;
683 	wr_regl(port, S3C2410_UCON, ucon);
684 
685 	ourport->rx_mode = S3C24XX_RX_DMA;
686 }
687 
688 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
689 {
690 	struct uart_port *port = &ourport->port;
691 	unsigned int ucon;
692 
693 	/* set Rx mode to DMA mode */
694 	ucon = rd_regl(port, S3C2410_UCON);
695 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
696 	ucon |= S3C64XX_UCON_RXMODE_CPU;
697 
698 	/* Apple types use these bits for IRQ masks */
699 	if (ourport->info->type != TYPE_APPLE_S5L) {
700 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
701 				S3C64XX_UCON_EMPTYINT_EN |
702 				S3C64XX_UCON_DMASUS_EN |
703 				S3C64XX_UCON_TIMEOUT_EN);
704 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
705 				S3C64XX_UCON_TIMEOUT_EN;
706 	}
707 	wr_regl(port, S3C2410_UCON, ucon);
708 
709 	ourport->rx_mode = S3C24XX_RX_PIO;
710 }
711 
712 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
713 
714 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
715 {
716 	unsigned int utrstat, received;
717 	struct s3c24xx_uart_port *ourport = dev_id;
718 	struct uart_port *port = &ourport->port;
719 	struct s3c24xx_uart_dma *dma = ourport->dma;
720 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
721 	struct tty_port *t = &port->state->port;
722 	struct dma_tx_state state;
723 
724 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
725 	rd_regl(port, S3C2410_UFSTAT);
726 
727 	spin_lock(&port->lock);
728 
729 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
730 		s3c64xx_start_rx_dma(ourport);
731 		if (ourport->rx_mode == S3C24XX_RX_PIO)
732 			enable_rx_dma(ourport);
733 		goto finish;
734 	}
735 
736 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
737 		dmaengine_pause(dma->rx_chan);
738 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
739 		dmaengine_terminate_all(dma->rx_chan);
740 		received = dma->rx_bytes_requested - state.residue;
741 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
742 
743 		enable_rx_pio(ourport);
744 	}
745 
746 	s3c24xx_serial_rx_drain_fifo(ourport);
747 
748 	if (tty) {
749 		tty_flip_buffer_push(t);
750 		tty_kref_put(tty);
751 	}
752 
753 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
754 
755 finish:
756 	spin_unlock(&port->lock);
757 
758 	return IRQ_HANDLED;
759 }
760 
761 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
762 {
763 	struct uart_port *port = &ourport->port;
764 	unsigned int ufcon, ch, flag, ufstat, uerstat;
765 	unsigned int fifocnt = 0;
766 	int max_count = port->fifosize;
767 
768 	while (max_count-- > 0) {
769 		/*
770 		 * Receive all characters known to be in FIFO
771 		 * before reading FIFO level again
772 		 */
773 		if (fifocnt == 0) {
774 			ufstat = rd_regl(port, S3C2410_UFSTAT);
775 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
776 			if (fifocnt == 0)
777 				break;
778 		}
779 		fifocnt--;
780 
781 		uerstat = rd_regl(port, S3C2410_UERSTAT);
782 		ch = rd_reg(port, S3C2410_URXH);
783 
784 		if (port->flags & UPF_CONS_FLOW) {
785 			int txe = s3c24xx_serial_txempty_nofifo(port);
786 
787 			if (ourport->rx_enabled) {
788 				if (!txe) {
789 					ourport->rx_enabled = 0;
790 					continue;
791 				}
792 			} else {
793 				if (txe) {
794 					ufcon = rd_regl(port, S3C2410_UFCON);
795 					ufcon |= S3C2410_UFCON_RESETRX;
796 					wr_regl(port, S3C2410_UFCON, ufcon);
797 					ourport->rx_enabled = 1;
798 					return;
799 				}
800 				continue;
801 			}
802 		}
803 
804 		/* insert the character into the buffer */
805 
806 		flag = TTY_NORMAL;
807 		port->icount.rx++;
808 
809 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
810 			dev_dbg(port->dev,
811 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
812 				ch, uerstat);
813 
814 			/* check for break */
815 			if (uerstat & S3C2410_UERSTAT_BREAK) {
816 				dev_dbg(port->dev, "break!\n");
817 				port->icount.brk++;
818 				if (uart_handle_break(port))
819 					continue; /* Ignore character */
820 			}
821 
822 			if (uerstat & S3C2410_UERSTAT_FRAME)
823 				port->icount.frame++;
824 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
825 				port->icount.overrun++;
826 
827 			uerstat &= port->read_status_mask;
828 
829 			if (uerstat & S3C2410_UERSTAT_BREAK)
830 				flag = TTY_BREAK;
831 			else if (uerstat & S3C2410_UERSTAT_PARITY)
832 				flag = TTY_PARITY;
833 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
834 					    S3C2410_UERSTAT_OVERRUN))
835 				flag = TTY_FRAME;
836 		}
837 
838 		if (uart_handle_sysrq_char(port, ch))
839 			continue; /* Ignore character */
840 
841 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
842 				 ch, flag);
843 	}
844 
845 	tty_flip_buffer_push(&port->state->port);
846 }
847 
848 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
849 {
850 	struct s3c24xx_uart_port *ourport = dev_id;
851 	struct uart_port *port = &ourport->port;
852 
853 	spin_lock(&port->lock);
854 	s3c24xx_serial_rx_drain_fifo(ourport);
855 	spin_unlock(&port->lock);
856 
857 	return IRQ_HANDLED;
858 }
859 
860 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
861 {
862 	struct s3c24xx_uart_port *ourport = dev_id;
863 
864 	if (ourport->dma && ourport->dma->rx_chan)
865 		return s3c24xx_serial_rx_chars_dma(dev_id);
866 	return s3c24xx_serial_rx_chars_pio(dev_id);
867 }
868 
869 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
870 {
871 	struct uart_port *port = &ourport->port;
872 	struct circ_buf *xmit = &port->state->xmit;
873 	int count, dma_count = 0;
874 
875 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
876 
877 	if (ourport->dma && ourport->dma->tx_chan &&
878 	    count >= ourport->min_dma_size) {
879 		int align = dma_get_cache_alignment() -
880 			(xmit->tail & (dma_get_cache_alignment() - 1));
881 		if (count - align >= ourport->min_dma_size) {
882 			dma_count = count - align;
883 			count = align;
884 		}
885 	}
886 
887 	if (port->x_char) {
888 		wr_reg(port, S3C2410_UTXH, port->x_char);
889 		port->icount.tx++;
890 		port->x_char = 0;
891 		return;
892 	}
893 
894 	/* if there isn't anything more to transmit, or the uart is now
895 	 * stopped, disable the uart and exit
896 	 */
897 
898 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
899 		s3c24xx_serial_stop_tx(port);
900 		return;
901 	}
902 
903 	/* try and drain the buffer... */
904 
905 	if (count > port->fifosize) {
906 		count = port->fifosize;
907 		dma_count = 0;
908 	}
909 
910 	while (!uart_circ_empty(xmit) && count > 0) {
911 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
912 			break;
913 
914 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
915 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
916 		port->icount.tx++;
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 		spin_unlock(&port->lock);
927 		uart_write_wakeup(port);
928 		spin_lock(&port->lock);
929 	}
930 
931 	if (uart_circ_empty(xmit))
932 		s3c24xx_serial_stop_tx(port);
933 }
934 
935 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
936 {
937 	struct s3c24xx_uart_port *ourport = id;
938 	struct uart_port *port = &ourport->port;
939 
940 	spin_lock(&port->lock);
941 
942 	s3c24xx_serial_tx_chars(ourport);
943 
944 	spin_unlock(&port->lock);
945 	return IRQ_HANDLED;
946 }
947 
948 /* interrupt handler for s3c64xx and later SoC's.*/
949 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
950 {
951 	struct s3c24xx_uart_port *ourport = id;
952 	struct uart_port *port = &ourport->port;
953 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
954 	irqreturn_t ret = IRQ_HANDLED;
955 
956 	if (pend & S3C64XX_UINTM_RXD_MSK) {
957 		ret = s3c24xx_serial_rx_irq(irq, id);
958 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
959 	}
960 	if (pend & S3C64XX_UINTM_TXD_MSK) {
961 		ret = s3c24xx_serial_tx_irq(irq, id);
962 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
963 	}
964 	return ret;
965 }
966 
967 /* interrupt handler for Apple SoC's.*/
968 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
969 {
970 	struct s3c24xx_uart_port *ourport = id;
971 	struct uart_port *port = &ourport->port;
972 	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
973 	irqreturn_t ret = IRQ_NONE;
974 
975 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
976 		wr_regl(port, S3C2410_UTRSTAT,
977 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
978 		ret = s3c24xx_serial_rx_irq(irq, id);
979 	}
980 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
981 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
982 		ret = s3c24xx_serial_tx_irq(irq, id);
983 	}
984 
985 	return ret;
986 }
987 
988 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
989 {
990 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
991 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
992 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
993 
994 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
995 		if ((ufstat & info->tx_fifomask) != 0 ||
996 		    (ufstat & info->tx_fifofull))
997 			return 0;
998 
999 		return 1;
1000 	}
1001 
1002 	return s3c24xx_serial_txempty_nofifo(port);
1003 }
1004 
1005 /* no modem control lines */
1006 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1007 {
1008 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
1009 
1010 	if (umstat & S3C2410_UMSTAT_CTS)
1011 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1012 	else
1013 		return TIOCM_CAR | TIOCM_DSR;
1014 }
1015 
1016 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1017 {
1018 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
1019 
1020 	if (mctrl & TIOCM_RTS)
1021 		umcon |= S3C2410_UMCOM_RTS_LOW;
1022 	else
1023 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1024 
1025 	wr_regl(port, S3C2410_UMCON, umcon);
1026 }
1027 
1028 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1029 {
1030 	unsigned long flags;
1031 	unsigned int ucon;
1032 
1033 	spin_lock_irqsave(&port->lock, flags);
1034 
1035 	ucon = rd_regl(port, S3C2410_UCON);
1036 
1037 	if (break_state)
1038 		ucon |= S3C2410_UCON_SBREAK;
1039 	else
1040 		ucon &= ~S3C2410_UCON_SBREAK;
1041 
1042 	wr_regl(port, S3C2410_UCON, ucon);
1043 
1044 	spin_unlock_irqrestore(&port->lock, flags);
1045 }
1046 
1047 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1048 {
1049 	struct s3c24xx_uart_dma	*dma = p->dma;
1050 	struct dma_slave_caps dma_caps;
1051 	const char *reason = NULL;
1052 	int ret;
1053 
1054 	/* Default slave configuration parameters */
1055 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1056 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1057 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1058 	dma->rx_conf.src_maxburst	= 1;
1059 
1060 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1061 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1062 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1063 	dma->tx_conf.dst_maxburst	= 1;
1064 
1065 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1066 
1067 	if (IS_ERR(dma->rx_chan)) {
1068 		reason = "DMA RX channel request failed";
1069 		ret = PTR_ERR(dma->rx_chan);
1070 		goto err_warn;
1071 	}
1072 
1073 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1074 	if (ret < 0 ||
1075 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1076 		reason = "insufficient DMA RX engine capabilities";
1077 		ret = -EOPNOTSUPP;
1078 		goto err_release_rx;
1079 	}
1080 
1081 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1082 
1083 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1084 	if (IS_ERR(dma->tx_chan)) {
1085 		reason = "DMA TX channel request failed";
1086 		ret = PTR_ERR(dma->tx_chan);
1087 		goto err_release_rx;
1088 	}
1089 
1090 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1091 	if (ret < 0 ||
1092 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1093 		reason = "insufficient DMA TX engine capabilities";
1094 		ret = -EOPNOTSUPP;
1095 		goto err_release_tx;
1096 	}
1097 
1098 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1099 
1100 	/* RX buffer */
1101 	dma->rx_size = PAGE_SIZE;
1102 
1103 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1104 	if (!dma->rx_buf) {
1105 		ret = -ENOMEM;
1106 		goto err_release_tx;
1107 	}
1108 
1109 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1110 				      dma->rx_size, DMA_FROM_DEVICE);
1111 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1112 		reason = "DMA mapping error for RX buffer";
1113 		ret = -EIO;
1114 		goto err_free_rx;
1115 	}
1116 
1117 	/* TX buffer */
1118 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1119 				      p->port.state->xmit.buf, UART_XMIT_SIZE,
1120 				      DMA_TO_DEVICE);
1121 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1122 		reason = "DMA mapping error for TX buffer";
1123 		ret = -EIO;
1124 		goto err_unmap_rx;
1125 	}
1126 
1127 	return 0;
1128 
1129 err_unmap_rx:
1130 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1131 			 dma->rx_size, DMA_FROM_DEVICE);
1132 err_free_rx:
1133 	kfree(dma->rx_buf);
1134 err_release_tx:
1135 	dma_release_channel(dma->tx_chan);
1136 err_release_rx:
1137 	dma_release_channel(dma->rx_chan);
1138 err_warn:
1139 	if (reason)
1140 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1141 	return ret;
1142 }
1143 
1144 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1145 {
1146 	struct s3c24xx_uart_dma	*dma = p->dma;
1147 
1148 	if (dma->rx_chan) {
1149 		dmaengine_terminate_all(dma->rx_chan);
1150 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1151 				 dma->rx_size, DMA_FROM_DEVICE);
1152 		kfree(dma->rx_buf);
1153 		dma_release_channel(dma->rx_chan);
1154 		dma->rx_chan = NULL;
1155 	}
1156 
1157 	if (dma->tx_chan) {
1158 		dmaengine_terminate_all(dma->tx_chan);
1159 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1160 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1161 		dma_release_channel(dma->tx_chan);
1162 		dma->tx_chan = NULL;
1163 	}
1164 }
1165 
1166 static void s3c24xx_serial_shutdown(struct uart_port *port)
1167 {
1168 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1169 
1170 	if (ourport->tx_claimed) {
1171 		free_irq(ourport->tx_irq, ourport);
1172 		ourport->tx_enabled = 0;
1173 		ourport->tx_claimed = 0;
1174 		ourport->tx_mode = 0;
1175 	}
1176 
1177 	if (ourport->rx_claimed) {
1178 		free_irq(ourport->rx_irq, ourport);
1179 		ourport->rx_claimed = 0;
1180 		ourport->rx_enabled = 0;
1181 	}
1182 
1183 	if (ourport->dma)
1184 		s3c24xx_serial_release_dma(ourport);
1185 
1186 	ourport->tx_in_progress = 0;
1187 }
1188 
1189 static void s3c64xx_serial_shutdown(struct uart_port *port)
1190 {
1191 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1192 
1193 	ourport->tx_enabled = 0;
1194 	ourport->tx_mode = 0;
1195 	ourport->rx_enabled = 0;
1196 
1197 	free_irq(port->irq, ourport);
1198 
1199 	wr_regl(port, S3C64XX_UINTP, 0xf);
1200 	wr_regl(port, S3C64XX_UINTM, 0xf);
1201 
1202 	if (ourport->dma)
1203 		s3c24xx_serial_release_dma(ourport);
1204 
1205 	ourport->tx_in_progress = 0;
1206 }
1207 
1208 static void apple_s5l_serial_shutdown(struct uart_port *port)
1209 {
1210 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1211 
1212 	unsigned int ucon;
1213 
1214 	ucon = rd_regl(port, S3C2410_UCON);
1215 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1216 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1217 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1218 	wr_regl(port, S3C2410_UCON, ucon);
1219 
1220 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1221 
1222 	free_irq(port->irq, ourport);
1223 
1224 	ourport->tx_enabled = 0;
1225 	ourport->tx_mode = 0;
1226 	ourport->rx_enabled = 0;
1227 
1228 	if (ourport->dma)
1229 		s3c24xx_serial_release_dma(ourport);
1230 
1231 	ourport->tx_in_progress = 0;
1232 }
1233 
1234 static int s3c24xx_serial_startup(struct uart_port *port)
1235 {
1236 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1237 	int ret;
1238 
1239 	ourport->rx_enabled = 1;
1240 
1241 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
1242 			  s3c24xx_serial_portname(port), ourport);
1243 
1244 	if (ret != 0) {
1245 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1246 		return ret;
1247 	}
1248 
1249 	ourport->rx_claimed = 1;
1250 
1251 	dev_dbg(port->dev, "requesting tx irq...\n");
1252 
1253 	ourport->tx_enabled = 1;
1254 
1255 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
1256 			  s3c24xx_serial_portname(port), ourport);
1257 
1258 	if (ret) {
1259 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1260 		goto err;
1261 	}
1262 
1263 	ourport->tx_claimed = 1;
1264 
1265 	/* the port reset code should have done the correct
1266 	 * register setup for the port controls
1267 	 */
1268 
1269 	return ret;
1270 
1271 err:
1272 	s3c24xx_serial_shutdown(port);
1273 	return ret;
1274 }
1275 
1276 static int s3c64xx_serial_startup(struct uart_port *port)
1277 {
1278 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1279 	unsigned long flags;
1280 	unsigned int ufcon;
1281 	int ret;
1282 
1283 	wr_regl(port, S3C64XX_UINTM, 0xf);
1284 	if (ourport->dma) {
1285 		ret = s3c24xx_serial_request_dma(ourport);
1286 		if (ret < 0) {
1287 			devm_kfree(port->dev, ourport->dma);
1288 			ourport->dma = NULL;
1289 		}
1290 	}
1291 
1292 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1293 			  s3c24xx_serial_portname(port), ourport);
1294 	if (ret) {
1295 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1296 		return ret;
1297 	}
1298 
1299 	/* For compatibility with s3c24xx Soc's */
1300 	ourport->rx_enabled = 1;
1301 	ourport->tx_enabled = 0;
1302 
1303 	spin_lock_irqsave(&port->lock, flags);
1304 
1305 	ufcon = rd_regl(port, S3C2410_UFCON);
1306 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1307 	if (!uart_console(port))
1308 		ufcon |= S3C2410_UFCON_RESETTX;
1309 	wr_regl(port, S3C2410_UFCON, ufcon);
1310 
1311 	enable_rx_pio(ourport);
1312 
1313 	spin_unlock_irqrestore(&port->lock, flags);
1314 
1315 	/* Enable Rx Interrupt */
1316 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1317 
1318 	return ret;
1319 }
1320 
1321 static int apple_s5l_serial_startup(struct uart_port *port)
1322 {
1323 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1324 	unsigned long flags;
1325 	unsigned int ufcon;
1326 	int ret;
1327 
1328 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1329 
1330 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1331 			  s3c24xx_serial_portname(port), ourport);
1332 	if (ret) {
1333 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1334 		return ret;
1335 	}
1336 
1337 	/* For compatibility with s3c24xx Soc's */
1338 	ourport->rx_enabled = 1;
1339 	ourport->tx_enabled = 0;
1340 
1341 	spin_lock_irqsave(&port->lock, flags);
1342 
1343 	ufcon = rd_regl(port, S3C2410_UFCON);
1344 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1345 	if (!uart_console(port))
1346 		ufcon |= S3C2410_UFCON_RESETTX;
1347 	wr_regl(port, S3C2410_UFCON, ufcon);
1348 
1349 	enable_rx_pio(ourport);
1350 
1351 	spin_unlock_irqrestore(&port->lock, flags);
1352 
1353 	/* Enable Rx Interrupt */
1354 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1355 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1356 
1357 	return ret;
1358 }
1359 
1360 static void exynos_usi_init(struct uart_port *port)
1361 {
1362 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1363 	struct s3c24xx_uart_info *info = ourport->info;
1364 	unsigned int val;
1365 
1366 	if (!info->has_usi)
1367 		return;
1368 
1369 	/* Clear the software reset of USI block (it's set at startup) */
1370 	val = rd_regl(port, USI_CON);
1371 	val &= ~USI_CON_RESET_MASK;
1372 	wr_regl(port, USI_CON, val);
1373 	udelay(1);
1374 
1375 	/* Continuously provide the clock to USI IP w/o gating (for Rx mode) */
1376 	val = rd_regl(port, USI_OPTION);
1377 	val &= ~USI_OPTION_HWACG_MASK;
1378 	val |= USI_OPTION_HWACG_CLKREQ_ON;
1379 	wr_regl(port, USI_OPTION, val);
1380 }
1381 
1382 /* power power management control */
1383 
1384 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1385 			      unsigned int old)
1386 {
1387 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1388 	int timeout = 10000;
1389 
1390 	ourport->pm_level = level;
1391 
1392 	switch (level) {
1393 	case 3:
1394 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1395 			udelay(100);
1396 
1397 		if (!IS_ERR(ourport->baudclk))
1398 			clk_disable_unprepare(ourport->baudclk);
1399 
1400 		clk_disable_unprepare(ourport->clk);
1401 		break;
1402 
1403 	case 0:
1404 		clk_prepare_enable(ourport->clk);
1405 
1406 		if (!IS_ERR(ourport->baudclk))
1407 			clk_prepare_enable(ourport->baudclk);
1408 
1409 		exynos_usi_init(port);
1410 		break;
1411 	default:
1412 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1413 	}
1414 }
1415 
1416 /* baud rate calculation
1417  *
1418  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1419  * of different sources, including the peripheral clock ("pclk") and an
1420  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1421  * with a programmable extra divisor.
1422  *
1423  * The following code goes through the clock sources, and calculates the
1424  * baud clocks (and the resultant actual baud rates) and then tries to
1425  * pick the closest one and select that.
1426  *
1427  */
1428 
1429 #define MAX_CLK_NAME_LENGTH 15
1430 
1431 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1432 {
1433 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1434 	unsigned int ucon;
1435 
1436 	if (info->num_clks == 1)
1437 		return 0;
1438 
1439 	ucon = rd_regl(port, S3C2410_UCON);
1440 	ucon &= info->clksel_mask;
1441 	return ucon >> info->clksel_shift;
1442 }
1443 
1444 static void s3c24xx_serial_setsource(struct uart_port *port,
1445 			unsigned int clk_sel)
1446 {
1447 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1448 	unsigned int ucon;
1449 
1450 	if (info->num_clks == 1)
1451 		return;
1452 
1453 	ucon = rd_regl(port, S3C2410_UCON);
1454 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1455 		return;
1456 
1457 	ucon &= ~info->clksel_mask;
1458 	ucon |= clk_sel << info->clksel_shift;
1459 	wr_regl(port, S3C2410_UCON, ucon);
1460 }
1461 
1462 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1463 			unsigned int req_baud, struct clk **best_clk,
1464 			unsigned int *clk_num)
1465 {
1466 	struct s3c24xx_uart_info *info = ourport->info;
1467 	struct clk *clk;
1468 	unsigned long rate;
1469 	unsigned int cnt, baud, quot, best_quot = 0;
1470 	char clkname[MAX_CLK_NAME_LENGTH];
1471 	int calc_deviation, deviation = (1 << 30) - 1;
1472 
1473 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1474 		/* Keep selected clock if provided */
1475 		if (ourport->cfg->clk_sel &&
1476 			!(ourport->cfg->clk_sel & (1 << cnt)))
1477 			continue;
1478 
1479 		sprintf(clkname, "clk_uart_baud%d", cnt);
1480 		clk = clk_get(ourport->port.dev, clkname);
1481 		if (IS_ERR(clk))
1482 			continue;
1483 
1484 		rate = clk_get_rate(clk);
1485 		if (!rate)
1486 			continue;
1487 
1488 		if (ourport->info->has_divslot) {
1489 			unsigned long div = rate / req_baud;
1490 
1491 			/* The UDIVSLOT register on the newer UARTs allows us to
1492 			 * get a divisor adjustment of 1/16th on the baud clock.
1493 			 *
1494 			 * We don't keep the UDIVSLOT value (the 16ths we
1495 			 * calculated by not multiplying the baud by 16) as it
1496 			 * is easy enough to recalculate.
1497 			 */
1498 
1499 			quot = div / 16;
1500 			baud = rate / div;
1501 		} else {
1502 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1503 			baud = rate / (quot * 16);
1504 		}
1505 		quot--;
1506 
1507 		calc_deviation = req_baud - baud;
1508 		if (calc_deviation < 0)
1509 			calc_deviation = -calc_deviation;
1510 
1511 		if (calc_deviation < deviation) {
1512 			*best_clk = clk;
1513 			best_quot = quot;
1514 			*clk_num = cnt;
1515 			deviation = calc_deviation;
1516 		}
1517 	}
1518 
1519 	return best_quot;
1520 }
1521 
1522 /* udivslot_table[]
1523  *
1524  * This table takes the fractional value of the baud divisor and gives
1525  * the recommended setting for the UDIVSLOT register.
1526  */
1527 static u16 udivslot_table[16] = {
1528 	[0] = 0x0000,
1529 	[1] = 0x0080,
1530 	[2] = 0x0808,
1531 	[3] = 0x0888,
1532 	[4] = 0x2222,
1533 	[5] = 0x4924,
1534 	[6] = 0x4A52,
1535 	[7] = 0x54AA,
1536 	[8] = 0x5555,
1537 	[9] = 0xD555,
1538 	[10] = 0xD5D5,
1539 	[11] = 0xDDD5,
1540 	[12] = 0xDDDD,
1541 	[13] = 0xDFDD,
1542 	[14] = 0xDFDF,
1543 	[15] = 0xFFDF,
1544 };
1545 
1546 static void s3c24xx_serial_set_termios(struct uart_port *port,
1547 				       struct ktermios *termios,
1548 				       struct ktermios *old)
1549 {
1550 	struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1551 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1552 	struct clk *clk = ERR_PTR(-EINVAL);
1553 	unsigned long flags;
1554 	unsigned int baud, quot, clk_sel = 0;
1555 	unsigned int ulcon;
1556 	unsigned int umcon;
1557 	unsigned int udivslot = 0;
1558 
1559 	/*
1560 	 * We don't support modem control lines.
1561 	 */
1562 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1563 	termios->c_cflag |= CLOCAL;
1564 
1565 	/*
1566 	 * Ask the core to calculate the divisor for us.
1567 	 */
1568 
1569 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1570 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1571 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1572 		quot = port->custom_divisor;
1573 	if (IS_ERR(clk))
1574 		return;
1575 
1576 	/* check to see if we need  to change clock source */
1577 
1578 	if (ourport->baudclk != clk) {
1579 		clk_prepare_enable(clk);
1580 
1581 		s3c24xx_serial_setsource(port, clk_sel);
1582 
1583 		if (!IS_ERR(ourport->baudclk)) {
1584 			clk_disable_unprepare(ourport->baudclk);
1585 			ourport->baudclk = ERR_PTR(-EINVAL);
1586 		}
1587 
1588 		ourport->baudclk = clk;
1589 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1590 	}
1591 
1592 	if (ourport->info->has_divslot) {
1593 		unsigned int div = ourport->baudclk_rate / baud;
1594 
1595 		if (cfg->has_fracval) {
1596 			udivslot = (div & 15);
1597 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1598 		} else {
1599 			udivslot = udivslot_table[div & 15];
1600 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1601 				udivslot, div & 15);
1602 		}
1603 	}
1604 
1605 	switch (termios->c_cflag & CSIZE) {
1606 	case CS5:
1607 		dev_dbg(port->dev, "config: 5bits/char\n");
1608 		ulcon = S3C2410_LCON_CS5;
1609 		break;
1610 	case CS6:
1611 		dev_dbg(port->dev, "config: 6bits/char\n");
1612 		ulcon = S3C2410_LCON_CS6;
1613 		break;
1614 	case CS7:
1615 		dev_dbg(port->dev, "config: 7bits/char\n");
1616 		ulcon = S3C2410_LCON_CS7;
1617 		break;
1618 	case CS8:
1619 	default:
1620 		dev_dbg(port->dev, "config: 8bits/char\n");
1621 		ulcon = S3C2410_LCON_CS8;
1622 		break;
1623 	}
1624 
1625 	/* preserve original lcon IR settings */
1626 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1627 
1628 	if (termios->c_cflag & CSTOPB)
1629 		ulcon |= S3C2410_LCON_STOPB;
1630 
1631 	if (termios->c_cflag & PARENB) {
1632 		if (termios->c_cflag & PARODD)
1633 			ulcon |= S3C2410_LCON_PODD;
1634 		else
1635 			ulcon |= S3C2410_LCON_PEVEN;
1636 	} else {
1637 		ulcon |= S3C2410_LCON_PNONE;
1638 	}
1639 
1640 	spin_lock_irqsave(&port->lock, flags);
1641 
1642 	dev_dbg(port->dev,
1643 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1644 		ulcon, quot, udivslot);
1645 
1646 	wr_regl(port, S3C2410_ULCON, ulcon);
1647 	wr_regl(port, S3C2410_UBRDIV, quot);
1648 
1649 	port->status &= ~UPSTAT_AUTOCTS;
1650 
1651 	umcon = rd_regl(port, S3C2410_UMCON);
1652 	if (termios->c_cflag & CRTSCTS) {
1653 		umcon |= S3C2410_UMCOM_AFC;
1654 		/* Disable RTS when RX FIFO contains 63 bytes */
1655 		umcon &= ~S3C2412_UMCON_AFC_8;
1656 		port->status = UPSTAT_AUTOCTS;
1657 	} else {
1658 		umcon &= ~S3C2410_UMCOM_AFC;
1659 	}
1660 	wr_regl(port, S3C2410_UMCON, umcon);
1661 
1662 	if (ourport->info->has_divslot)
1663 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1664 
1665 	dev_dbg(port->dev,
1666 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1667 		rd_regl(port, S3C2410_ULCON),
1668 		rd_regl(port, S3C2410_UCON),
1669 		rd_regl(port, S3C2410_UFCON));
1670 
1671 	/*
1672 	 * Update the per-port timeout.
1673 	 */
1674 	uart_update_timeout(port, termios->c_cflag, baud);
1675 
1676 	/*
1677 	 * Which character status flags are we interested in?
1678 	 */
1679 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1680 	if (termios->c_iflag & INPCK)
1681 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1682 			S3C2410_UERSTAT_PARITY;
1683 	/*
1684 	 * Which character status flags should we ignore?
1685 	 */
1686 	port->ignore_status_mask = 0;
1687 	if (termios->c_iflag & IGNPAR)
1688 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1689 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1690 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1691 
1692 	/*
1693 	 * Ignore all characters if CREAD is not set.
1694 	 */
1695 	if ((termios->c_cflag & CREAD) == 0)
1696 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1697 
1698 	spin_unlock_irqrestore(&port->lock, flags);
1699 }
1700 
1701 static const char *s3c24xx_serial_type(struct uart_port *port)
1702 {
1703 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1704 
1705 	switch (ourport->info->type) {
1706 	case TYPE_S3C24XX:
1707 		return "S3C24XX";
1708 	case TYPE_S3C6400:
1709 		return "S3C6400/10";
1710 	case TYPE_APPLE_S5L:
1711 		return "APPLE S5L";
1712 	default:
1713 		return NULL;
1714 	}
1715 }
1716 
1717 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1718 {
1719 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1720 
1721 	if (flags & UART_CONFIG_TYPE)
1722 		port->type = info->port_type;
1723 }
1724 
1725 /*
1726  * verify the new serial_struct (for TIOCSSERIAL).
1727  */
1728 static int
1729 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1730 {
1731 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1732 
1733 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1734 		return -EINVAL;
1735 
1736 	return 0;
1737 }
1738 
1739 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1740 
1741 static struct console s3c24xx_serial_console;
1742 
1743 static int __init s3c24xx_serial_console_init(void)
1744 {
1745 	register_console(&s3c24xx_serial_console);
1746 	return 0;
1747 }
1748 console_initcall(s3c24xx_serial_console_init);
1749 
1750 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1751 #else
1752 #define S3C24XX_SERIAL_CONSOLE NULL
1753 #endif
1754 
1755 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1756 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1757 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1758 			 unsigned char c);
1759 #endif
1760 
1761 static const struct uart_ops s3c24xx_serial_ops = {
1762 	.pm		= s3c24xx_serial_pm,
1763 	.tx_empty	= s3c24xx_serial_tx_empty,
1764 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1765 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1766 	.stop_tx	= s3c24xx_serial_stop_tx,
1767 	.start_tx	= s3c24xx_serial_start_tx,
1768 	.stop_rx	= s3c24xx_serial_stop_rx,
1769 	.break_ctl	= s3c24xx_serial_break_ctl,
1770 	.startup	= s3c24xx_serial_startup,
1771 	.shutdown	= s3c24xx_serial_shutdown,
1772 	.set_termios	= s3c24xx_serial_set_termios,
1773 	.type		= s3c24xx_serial_type,
1774 	.config_port	= s3c24xx_serial_config_port,
1775 	.verify_port	= s3c24xx_serial_verify_port,
1776 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1777 	.poll_get_char = s3c24xx_serial_get_poll_char,
1778 	.poll_put_char = s3c24xx_serial_put_poll_char,
1779 #endif
1780 };
1781 
1782 static const struct uart_ops s3c64xx_serial_ops = {
1783 	.pm		= s3c24xx_serial_pm,
1784 	.tx_empty	= s3c24xx_serial_tx_empty,
1785 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1786 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1787 	.stop_tx	= s3c24xx_serial_stop_tx,
1788 	.start_tx	= s3c24xx_serial_start_tx,
1789 	.stop_rx	= s3c24xx_serial_stop_rx,
1790 	.break_ctl	= s3c24xx_serial_break_ctl,
1791 	.startup	= s3c64xx_serial_startup,
1792 	.shutdown	= s3c64xx_serial_shutdown,
1793 	.set_termios	= s3c24xx_serial_set_termios,
1794 	.type		= s3c24xx_serial_type,
1795 	.config_port	= s3c24xx_serial_config_port,
1796 	.verify_port	= s3c24xx_serial_verify_port,
1797 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1798 	.poll_get_char = s3c24xx_serial_get_poll_char,
1799 	.poll_put_char = s3c24xx_serial_put_poll_char,
1800 #endif
1801 };
1802 
1803 static const struct uart_ops apple_s5l_serial_ops = {
1804 	.pm		= s3c24xx_serial_pm,
1805 	.tx_empty	= s3c24xx_serial_tx_empty,
1806 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1807 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1808 	.stop_tx	= s3c24xx_serial_stop_tx,
1809 	.start_tx	= s3c24xx_serial_start_tx,
1810 	.stop_rx	= s3c24xx_serial_stop_rx,
1811 	.break_ctl	= s3c24xx_serial_break_ctl,
1812 	.startup	= apple_s5l_serial_startup,
1813 	.shutdown	= apple_s5l_serial_shutdown,
1814 	.set_termios	= s3c24xx_serial_set_termios,
1815 	.type		= s3c24xx_serial_type,
1816 	.config_port	= s3c24xx_serial_config_port,
1817 	.verify_port	= s3c24xx_serial_verify_port,
1818 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1819 	.poll_get_char = s3c24xx_serial_get_poll_char,
1820 	.poll_put_char = s3c24xx_serial_put_poll_char,
1821 #endif
1822 };
1823 
1824 static struct uart_driver s3c24xx_uart_drv = {
1825 	.owner		= THIS_MODULE,
1826 	.driver_name	= "s3c2410_serial",
1827 	.nr		= CONFIG_SERIAL_SAMSUNG_UARTS,
1828 	.cons		= S3C24XX_SERIAL_CONSOLE,
1829 	.dev_name	= S3C24XX_SERIAL_NAME,
1830 	.major		= S3C24XX_SERIAL_MAJOR,
1831 	.minor		= S3C24XX_SERIAL_MINOR,
1832 };
1833 
1834 #define __PORT_LOCK_UNLOCKED(i) \
1835 	__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[i].port.lock)
1836 static struct s3c24xx_uart_port
1837 s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
1838 	[0] = {
1839 		.port = {
1840 			.lock		= __PORT_LOCK_UNLOCKED(0),
1841 			.iotype		= UPIO_MEM,
1842 			.uartclk	= 0,
1843 			.fifosize	= 16,
1844 			.ops		= &s3c24xx_serial_ops,
1845 			.flags		= UPF_BOOT_AUTOCONF,
1846 			.line		= 0,
1847 		}
1848 	},
1849 	[1] = {
1850 		.port = {
1851 			.lock		= __PORT_LOCK_UNLOCKED(1),
1852 			.iotype		= UPIO_MEM,
1853 			.uartclk	= 0,
1854 			.fifosize	= 16,
1855 			.ops		= &s3c24xx_serial_ops,
1856 			.flags		= UPF_BOOT_AUTOCONF,
1857 			.line		= 1,
1858 		}
1859 	},
1860 #if CONFIG_SERIAL_SAMSUNG_UARTS > 2
1861 	[2] = {
1862 		.port = {
1863 			.lock		= __PORT_LOCK_UNLOCKED(2),
1864 			.iotype		= UPIO_MEM,
1865 			.uartclk	= 0,
1866 			.fifosize	= 16,
1867 			.ops		= &s3c24xx_serial_ops,
1868 			.flags		= UPF_BOOT_AUTOCONF,
1869 			.line		= 2,
1870 		}
1871 	},
1872 #endif
1873 #if CONFIG_SERIAL_SAMSUNG_UARTS > 3
1874 	[3] = {
1875 		.port = {
1876 			.lock		= __PORT_LOCK_UNLOCKED(3),
1877 			.iotype		= UPIO_MEM,
1878 			.uartclk	= 0,
1879 			.fifosize	= 16,
1880 			.ops		= &s3c24xx_serial_ops,
1881 			.flags		= UPF_BOOT_AUTOCONF,
1882 			.line		= 3,
1883 		}
1884 	}
1885 #endif
1886 };
1887 #undef __PORT_LOCK_UNLOCKED
1888 
1889 /* s3c24xx_serial_resetport
1890  *
1891  * reset the fifos and other the settings.
1892  */
1893 
1894 static void s3c24xx_serial_resetport(struct uart_port *port,
1895 				   struct s3c2410_uartcfg *cfg)
1896 {
1897 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1898 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1899 
1900 	ucon &= (info->clksel_mask | info->ucon_mask);
1901 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1902 
1903 	/* reset both fifos */
1904 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1905 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1906 
1907 	/* some delay is required after fifo reset */
1908 	udelay(1);
1909 }
1910 
1911 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1912 
1913 static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1914 					     unsigned long val, void *data)
1915 {
1916 	struct s3c24xx_uart_port *port;
1917 	struct uart_port *uport;
1918 
1919 	port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1920 	uport = &port->port;
1921 
1922 	/* check to see if port is enabled */
1923 
1924 	if (port->pm_level != 0)
1925 		return 0;
1926 
1927 	/* try and work out if the baudrate is changing, we can detect
1928 	 * a change in rate, but we do not have support for detecting
1929 	 * a disturbance in the clock-rate over the change.
1930 	 */
1931 
1932 	if (IS_ERR(port->baudclk))
1933 		goto exit;
1934 
1935 	if (port->baudclk_rate == clk_get_rate(port->baudclk))
1936 		goto exit;
1937 
1938 	if (val == CPUFREQ_PRECHANGE) {
1939 		/* we should really shut the port down whilst the
1940 		 * frequency change is in progress.
1941 		 */
1942 
1943 	} else if (val == CPUFREQ_POSTCHANGE) {
1944 		struct ktermios *termios;
1945 		struct tty_struct *tty;
1946 
1947 		if (uport->state == NULL)
1948 			goto exit;
1949 
1950 		tty = uport->state->port.tty;
1951 
1952 		if (tty == NULL)
1953 			goto exit;
1954 
1955 		termios = &tty->termios;
1956 
1957 		if (termios == NULL) {
1958 			dev_warn(uport->dev, "%s: no termios?\n", __func__);
1959 			goto exit;
1960 		}
1961 
1962 		s3c24xx_serial_set_termios(uport, termios, NULL);
1963 	}
1964 
1965 exit:
1966 	return 0;
1967 }
1968 
1969 static inline int
1970 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1971 {
1972 	port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1973 
1974 	return cpufreq_register_notifier(&port->freq_transition,
1975 					 CPUFREQ_TRANSITION_NOTIFIER);
1976 }
1977 
1978 static inline void
1979 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1980 {
1981 	cpufreq_unregister_notifier(&port->freq_transition,
1982 				    CPUFREQ_TRANSITION_NOTIFIER);
1983 }
1984 
1985 #else
1986 static inline int
1987 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1988 {
1989 	return 0;
1990 }
1991 
1992 static inline void
1993 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1994 {
1995 }
1996 #endif
1997 
1998 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1999 {
2000 	struct device *dev = ourport->port.dev;
2001 	struct s3c24xx_uart_info *info = ourport->info;
2002 	char clk_name[MAX_CLK_NAME_LENGTH];
2003 	unsigned int clk_sel;
2004 	struct clk *clk;
2005 	int clk_num;
2006 	int ret;
2007 
2008 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
2009 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
2010 		if (!(clk_sel & (1 << clk_num)))
2011 			continue;
2012 
2013 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
2014 		clk = clk_get(dev, clk_name);
2015 		if (IS_ERR(clk))
2016 			continue;
2017 
2018 		ret = clk_prepare_enable(clk);
2019 		if (ret) {
2020 			clk_put(clk);
2021 			continue;
2022 		}
2023 
2024 		ourport->baudclk = clk;
2025 		ourport->baudclk_rate = clk_get_rate(clk);
2026 		s3c24xx_serial_setsource(&ourport->port, clk_num);
2027 
2028 		return 0;
2029 	}
2030 
2031 	return -EINVAL;
2032 }
2033 
2034 /* s3c24xx_serial_init_port
2035  *
2036  * initialise a single serial port from the platform device given
2037  */
2038 
2039 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
2040 				    struct platform_device *platdev)
2041 {
2042 	struct uart_port *port = &ourport->port;
2043 	struct s3c2410_uartcfg *cfg = ourport->cfg;
2044 	struct resource *res;
2045 	int ret;
2046 
2047 	if (platdev == NULL)
2048 		return -ENODEV;
2049 
2050 	if (port->mapbase != 0)
2051 		return -EINVAL;
2052 
2053 	/* setup info for port */
2054 	port->dev	= &platdev->dev;
2055 
2056 	port->uartclk = 1;
2057 
2058 	if (cfg->uart_flags & UPF_CONS_FLOW) {
2059 		dev_dbg(port->dev, "enabling flow control\n");
2060 		port->flags |= UPF_CONS_FLOW;
2061 	}
2062 
2063 	/* sort our the physical and virtual addresses for each UART */
2064 
2065 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
2066 	if (res == NULL) {
2067 		dev_err(port->dev, "failed to find memory resource for uart\n");
2068 		return -EINVAL;
2069 	}
2070 
2071 	dev_dbg(port->dev, "resource %pR)\n", res);
2072 
2073 	port->membase = devm_ioremap_resource(port->dev, res);
2074 	if (IS_ERR(port->membase)) {
2075 		dev_err(port->dev, "failed to remap controller address\n");
2076 		return -EBUSY;
2077 	}
2078 
2079 	port->mapbase = res->start;
2080 	ret = platform_get_irq(platdev, 0);
2081 	if (ret < 0) {
2082 		port->irq = 0;
2083 	} else {
2084 		port->irq = ret;
2085 		ourport->rx_irq = ret;
2086 		ourport->tx_irq = ret + 1;
2087 	}
2088 
2089 	switch (ourport->info->type) {
2090 	case TYPE_S3C24XX:
2091 		ret = platform_get_irq(platdev, 1);
2092 		if (ret > 0)
2093 			ourport->tx_irq = ret;
2094 		break;
2095 	default:
2096 		break;
2097 	}
2098 
2099 	/*
2100 	 * DMA is currently supported only on DT platforms, if DMA properties
2101 	 * are specified.
2102 	 */
2103 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
2104 						     "dmas", NULL)) {
2105 		ourport->dma = devm_kzalloc(port->dev,
2106 					    sizeof(*ourport->dma),
2107 					    GFP_KERNEL);
2108 		if (!ourport->dma) {
2109 			ret = -ENOMEM;
2110 			goto err;
2111 		}
2112 	}
2113 
2114 	ourport->clk	= clk_get(&platdev->dev, "uart");
2115 	if (IS_ERR(ourport->clk)) {
2116 		pr_err("%s: Controller clock not found\n",
2117 				dev_name(&platdev->dev));
2118 		ret = PTR_ERR(ourport->clk);
2119 		goto err;
2120 	}
2121 
2122 	ret = clk_prepare_enable(ourport->clk);
2123 	if (ret) {
2124 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
2125 		clk_put(ourport->clk);
2126 		goto err;
2127 	}
2128 
2129 	ret = s3c24xx_serial_enable_baudclk(ourport);
2130 	if (ret)
2131 		pr_warn("uart: failed to enable baudclk\n");
2132 
2133 	exynos_usi_init(port);
2134 
2135 	/* Keep all interrupts masked and cleared */
2136 	switch (ourport->info->type) {
2137 	case TYPE_S3C6400:
2138 		wr_regl(port, S3C64XX_UINTM, 0xf);
2139 		wr_regl(port, S3C64XX_UINTP, 0xf);
2140 		wr_regl(port, S3C64XX_UINTSP, 0xf);
2141 		break;
2142 	case TYPE_APPLE_S5L: {
2143 		unsigned int ucon;
2144 
2145 		ucon = rd_regl(port, S3C2410_UCON);
2146 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2147 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2148 			APPLE_S5L_UCON_RXTO_ENA_MSK);
2149 		wr_regl(port, S3C2410_UCON, ucon);
2150 
2151 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
2152 		break;
2153 	}
2154 	default:
2155 		break;
2156 	}
2157 
2158 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
2159 		&port->mapbase, port->membase, port->irq,
2160 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
2161 
2162 	/* reset the fifos (and setup the uart) */
2163 	s3c24xx_serial_resetport(port, cfg);
2164 
2165 	return 0;
2166 
2167 err:
2168 	port->mapbase = 0;
2169 	return ret;
2170 }
2171 
2172 /* Device driver serial port probe */
2173 
2174 #ifdef CONFIG_OF
2175 static const struct of_device_id s3c24xx_uart_dt_match[];
2176 #endif
2177 
2178 static int probe_index;
2179 
2180 static inline struct s3c24xx_serial_drv_data *
2181 s3c24xx_get_driver_data(struct platform_device *pdev)
2182 {
2183 #ifdef CONFIG_OF
2184 	if (pdev->dev.of_node) {
2185 		const struct of_device_id *match;
2186 
2187 		match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
2188 		return (struct s3c24xx_serial_drv_data *)match->data;
2189 	}
2190 #endif
2191 	return (struct s3c24xx_serial_drv_data *)
2192 			platform_get_device_id(pdev)->driver_data;
2193 }
2194 
2195 static int s3c24xx_serial_probe(struct platform_device *pdev)
2196 {
2197 	struct device_node *np = pdev->dev.of_node;
2198 	struct s3c24xx_uart_port *ourport;
2199 	int index = probe_index;
2200 	int ret, prop = 0;
2201 
2202 	if (np) {
2203 		ret = of_alias_get_id(np, "serial");
2204 		if (ret >= 0)
2205 			index = ret;
2206 	}
2207 
2208 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2209 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2210 		return -EINVAL;
2211 	}
2212 	ourport = &s3c24xx_serial_ports[index];
2213 
2214 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2215 	if (!ourport->drv_data) {
2216 		dev_err(&pdev->dev, "could not find driver data\n");
2217 		return -ENODEV;
2218 	}
2219 
2220 	ourport->baudclk = ERR_PTR(-EINVAL);
2221 	ourport->info = ourport->drv_data->info;
2222 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2223 			dev_get_platdata(&pdev->dev) :
2224 			ourport->drv_data->def_cfg;
2225 
2226 	switch (ourport->info->type) {
2227 	case TYPE_S3C24XX:
2228 		ourport->port.ops = &s3c24xx_serial_ops;
2229 		break;
2230 	case TYPE_S3C6400:
2231 		ourport->port.ops = &s3c64xx_serial_ops;
2232 		break;
2233 	case TYPE_APPLE_S5L:
2234 		ourport->port.ops = &apple_s5l_serial_ops;
2235 		break;
2236 	}
2237 
2238 	if (np) {
2239 		of_property_read_u32(np,
2240 			"samsung,uart-fifosize", &ourport->port.fifosize);
2241 
2242 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2243 			switch (prop) {
2244 			case 1:
2245 				ourport->port.iotype = UPIO_MEM;
2246 				break;
2247 			case 4:
2248 				ourport->port.iotype = UPIO_MEM32;
2249 				break;
2250 			default:
2251 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2252 						prop);
2253 				return -EINVAL;
2254 			}
2255 		}
2256 	}
2257 
2258 	if (ourport->drv_data->fifosize[index])
2259 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2260 	else if (ourport->info->fifosize)
2261 		ourport->port.fifosize = ourport->info->fifosize;
2262 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2263 
2264 	/*
2265 	 * DMA transfers must be aligned at least to cache line size,
2266 	 * so find minimal transfer size suitable for DMA mode
2267 	 */
2268 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2269 				    dma_get_cache_alignment());
2270 
2271 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2272 
2273 	ret = s3c24xx_serial_init_port(ourport, pdev);
2274 	if (ret < 0)
2275 		return ret;
2276 
2277 	if (!s3c24xx_uart_drv.state) {
2278 		ret = uart_register_driver(&s3c24xx_uart_drv);
2279 		if (ret < 0) {
2280 			pr_err("Failed to register Samsung UART driver\n");
2281 			return ret;
2282 		}
2283 	}
2284 
2285 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2286 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2287 	platform_set_drvdata(pdev, &ourport->port);
2288 
2289 	/*
2290 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2291 	 * so that a potential re-enablement through the pm-callback overlaps
2292 	 * and keeps the clock enabled in this case.
2293 	 */
2294 	clk_disable_unprepare(ourport->clk);
2295 	if (!IS_ERR(ourport->baudclk))
2296 		clk_disable_unprepare(ourport->baudclk);
2297 
2298 	ret = s3c24xx_serial_cpufreq_register(ourport);
2299 	if (ret < 0)
2300 		dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
2301 
2302 	probe_index++;
2303 
2304 	return 0;
2305 }
2306 
2307 static int s3c24xx_serial_remove(struct platform_device *dev)
2308 {
2309 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2310 
2311 	if (port) {
2312 		s3c24xx_serial_cpufreq_deregister(to_ourport(port));
2313 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2314 	}
2315 
2316 	uart_unregister_driver(&s3c24xx_uart_drv);
2317 
2318 	return 0;
2319 }
2320 
2321 /* UART power management code */
2322 #ifdef CONFIG_PM_SLEEP
2323 static int s3c24xx_serial_suspend(struct device *dev)
2324 {
2325 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2326 
2327 	if (port)
2328 		uart_suspend_port(&s3c24xx_uart_drv, port);
2329 
2330 	return 0;
2331 }
2332 
2333 static int s3c24xx_serial_resume(struct device *dev)
2334 {
2335 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2336 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2337 
2338 	if (port) {
2339 		clk_prepare_enable(ourport->clk);
2340 		if (!IS_ERR(ourport->baudclk))
2341 			clk_prepare_enable(ourport->baudclk);
2342 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2343 		if (!IS_ERR(ourport->baudclk))
2344 			clk_disable_unprepare(ourport->baudclk);
2345 		clk_disable_unprepare(ourport->clk);
2346 
2347 		uart_resume_port(&s3c24xx_uart_drv, port);
2348 	}
2349 
2350 	return 0;
2351 }
2352 
2353 static int s3c24xx_serial_resume_noirq(struct device *dev)
2354 {
2355 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2356 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2357 
2358 	if (port) {
2359 		/* restore IRQ mask */
2360 		switch (ourport->info->type) {
2361 		case TYPE_S3C6400: {
2362 			unsigned int uintm = 0xf;
2363 
2364 			if (ourport->tx_enabled)
2365 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2366 			if (ourport->rx_enabled)
2367 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2368 			clk_prepare_enable(ourport->clk);
2369 			if (!IS_ERR(ourport->baudclk))
2370 				clk_prepare_enable(ourport->baudclk);
2371 			wr_regl(port, S3C64XX_UINTM, uintm);
2372 			if (!IS_ERR(ourport->baudclk))
2373 				clk_disable_unprepare(ourport->baudclk);
2374 			clk_disable_unprepare(ourport->clk);
2375 			break;
2376 		}
2377 		case TYPE_APPLE_S5L: {
2378 			unsigned int ucon;
2379 			int ret;
2380 
2381 			ret = clk_prepare_enable(ourport->clk);
2382 			if (ret) {
2383 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2384 				return ret;
2385 			}
2386 			if (!IS_ERR(ourport->baudclk)) {
2387 				ret = clk_prepare_enable(ourport->baudclk);
2388 				if (ret) {
2389 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2390 					clk_disable_unprepare(ourport->clk);
2391 					return ret;
2392 				}
2393 			}
2394 
2395 			ucon = rd_regl(port, S3C2410_UCON);
2396 
2397 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2398 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2399 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2400 
2401 			if (ourport->tx_enabled)
2402 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2403 			if (ourport->rx_enabled)
2404 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2405 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2406 
2407 			wr_regl(port, S3C2410_UCON, ucon);
2408 
2409 			if (!IS_ERR(ourport->baudclk))
2410 				clk_disable_unprepare(ourport->baudclk);
2411 			clk_disable_unprepare(ourport->clk);
2412 			break;
2413 		}
2414 		default:
2415 			break;
2416 		}
2417 	}
2418 
2419 	return 0;
2420 }
2421 
2422 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2423 	.suspend = s3c24xx_serial_suspend,
2424 	.resume = s3c24xx_serial_resume,
2425 	.resume_noirq = s3c24xx_serial_resume_noirq,
2426 };
2427 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2428 
2429 #else /* !CONFIG_PM_SLEEP */
2430 
2431 #define SERIAL_SAMSUNG_PM_OPS	NULL
2432 #endif /* CONFIG_PM_SLEEP */
2433 
2434 /* Console code */
2435 
2436 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2437 
2438 static struct uart_port *cons_uart;
2439 
2440 static int
2441 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2442 {
2443 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2444 	unsigned long ufstat, utrstat;
2445 
2446 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2447 		/* fifo mode - check amount of data in fifo registers... */
2448 
2449 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2450 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2451 	}
2452 
2453 	/* in non-fifo mode, we go and use the tx buffer empty */
2454 
2455 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2456 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2457 }
2458 
2459 static bool
2460 s3c24xx_port_configured(unsigned int ucon)
2461 {
2462 	/* consider the serial port configured if the tx/rx mode set */
2463 	return (ucon & 0xf) != 0;
2464 }
2465 
2466 #ifdef CONFIG_CONSOLE_POLL
2467 /*
2468  * Console polling routines for writing and reading from the uart while
2469  * in an interrupt or debug context.
2470  */
2471 
2472 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2473 {
2474 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2475 	unsigned int ufstat;
2476 
2477 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2478 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2479 		return NO_POLL_CHAR;
2480 
2481 	return rd_reg(port, S3C2410_URXH);
2482 }
2483 
2484 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2485 		unsigned char c)
2486 {
2487 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2488 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2489 
2490 	/* not possible to xmit on unconfigured port */
2491 	if (!s3c24xx_port_configured(ucon))
2492 		return;
2493 
2494 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2495 		cpu_relax();
2496 	wr_reg(port, S3C2410_UTXH, c);
2497 }
2498 
2499 #endif /* CONFIG_CONSOLE_POLL */
2500 
2501 static void
2502 s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
2503 {
2504 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2505 
2506 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2507 		cpu_relax();
2508 	wr_reg(port, S3C2410_UTXH, ch);
2509 }
2510 
2511 static void
2512 s3c24xx_serial_console_write(struct console *co, const char *s,
2513 			     unsigned int count)
2514 {
2515 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2516 
2517 	/* not possible to xmit on unconfigured port */
2518 	if (!s3c24xx_port_configured(ucon))
2519 		return;
2520 
2521 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2522 }
2523 
2524 static void __init
2525 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2526 			   int *parity, int *bits)
2527 {
2528 	struct clk *clk;
2529 	unsigned int ulcon;
2530 	unsigned int ucon;
2531 	unsigned int ubrdiv;
2532 	unsigned long rate;
2533 	unsigned int clk_sel;
2534 	char clk_name[MAX_CLK_NAME_LENGTH];
2535 
2536 	ulcon  = rd_regl(port, S3C2410_ULCON);
2537 	ucon   = rd_regl(port, S3C2410_UCON);
2538 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2539 
2540 	if (s3c24xx_port_configured(ucon)) {
2541 		switch (ulcon & S3C2410_LCON_CSMASK) {
2542 		case S3C2410_LCON_CS5:
2543 			*bits = 5;
2544 			break;
2545 		case S3C2410_LCON_CS6:
2546 			*bits = 6;
2547 			break;
2548 		case S3C2410_LCON_CS7:
2549 			*bits = 7;
2550 			break;
2551 		case S3C2410_LCON_CS8:
2552 		default:
2553 			*bits = 8;
2554 			break;
2555 		}
2556 
2557 		switch (ulcon & S3C2410_LCON_PMASK) {
2558 		case S3C2410_LCON_PEVEN:
2559 			*parity = 'e';
2560 			break;
2561 
2562 		case S3C2410_LCON_PODD:
2563 			*parity = 'o';
2564 			break;
2565 
2566 		case S3C2410_LCON_PNONE:
2567 		default:
2568 			*parity = 'n';
2569 		}
2570 
2571 		/* now calculate the baud rate */
2572 
2573 		clk_sel = s3c24xx_serial_getsource(port);
2574 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2575 
2576 		clk = clk_get(port->dev, clk_name);
2577 		if (!IS_ERR(clk))
2578 			rate = clk_get_rate(clk);
2579 		else
2580 			rate = 1;
2581 
2582 		*baud = rate / (16 * (ubrdiv + 1));
2583 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2584 	}
2585 }
2586 
2587 static int __init
2588 s3c24xx_serial_console_setup(struct console *co, char *options)
2589 {
2590 	struct uart_port *port;
2591 	int baud = 9600;
2592 	int bits = 8;
2593 	int parity = 'n';
2594 	int flow = 'n';
2595 
2596 	/* is this a valid port */
2597 
2598 	if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
2599 		co->index = 0;
2600 
2601 	port = &s3c24xx_serial_ports[co->index].port;
2602 
2603 	/* is the port configured? */
2604 
2605 	if (port->mapbase == 0x0)
2606 		return -ENODEV;
2607 
2608 	cons_uart = port;
2609 
2610 	/*
2611 	 * Check whether an invalid uart number has been specified, and
2612 	 * if so, search for the first available port that does have
2613 	 * console support.
2614 	 */
2615 	if (options)
2616 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2617 	else
2618 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2619 
2620 	dev_dbg(port->dev, "baud %d\n", baud);
2621 
2622 	return uart_set_options(port, co, baud, parity, bits, flow);
2623 }
2624 
2625 static struct console s3c24xx_serial_console = {
2626 	.name		= S3C24XX_SERIAL_NAME,
2627 	.device		= uart_console_device,
2628 	.flags		= CON_PRINTBUFFER,
2629 	.index		= -1,
2630 	.write		= s3c24xx_serial_console_write,
2631 	.setup		= s3c24xx_serial_console_setup,
2632 	.data		= &s3c24xx_uart_drv,
2633 };
2634 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2635 
2636 #ifdef CONFIG_CPU_S3C2410
2637 static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
2638 	.info = &(struct s3c24xx_uart_info) {
2639 		.name		= "Samsung S3C2410 UART",
2640 		.type		= TYPE_S3C24XX,
2641 		.port_type	= PORT_S3C2410,
2642 		.fifosize	= 16,
2643 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2644 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2645 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2646 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2647 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2648 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2649 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2650 		.num_clks	= 2,
2651 		.clksel_mask	= S3C2410_UCON_CLKMASK,
2652 		.clksel_shift	= S3C2410_UCON_CLKSHIFT,
2653 	},
2654 	.def_cfg = &(struct s3c2410_uartcfg) {
2655 		.ucon		= S3C2410_UCON_DEFAULT,
2656 		.ufcon		= S3C2410_UFCON_DEFAULT,
2657 	},
2658 };
2659 #define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
2660 #else
2661 #define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2662 #endif
2663 
2664 #ifdef CONFIG_CPU_S3C2412
2665 static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
2666 	.info = &(struct s3c24xx_uart_info) {
2667 		.name		= "Samsung S3C2412 UART",
2668 		.type		= TYPE_S3C24XX,
2669 		.port_type	= PORT_S3C2412,
2670 		.fifosize	= 64,
2671 		.has_divslot	= 1,
2672 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2673 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2674 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2675 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2676 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2677 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2678 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2679 		.num_clks	= 4,
2680 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2681 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2682 	},
2683 	.def_cfg = &(struct s3c2410_uartcfg) {
2684 		.ucon		= S3C2410_UCON_DEFAULT,
2685 		.ufcon		= S3C2410_UFCON_DEFAULT,
2686 	},
2687 };
2688 #define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
2689 #else
2690 #define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2691 #endif
2692 
2693 #if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
2694 	defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
2695 static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
2696 	.info = &(struct s3c24xx_uart_info) {
2697 		.name		= "Samsung S3C2440 UART",
2698 		.type		= TYPE_S3C24XX,
2699 		.port_type	= PORT_S3C2440,
2700 		.fifosize	= 64,
2701 		.has_divslot	= 1,
2702 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2703 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2704 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2705 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2706 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2707 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2708 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2709 		.num_clks	= 4,
2710 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2711 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2712 		.ucon_mask	= S3C2440_UCON0_DIVMASK,
2713 	},
2714 	.def_cfg = &(struct s3c2410_uartcfg) {
2715 		.ucon		= S3C2410_UCON_DEFAULT,
2716 		.ufcon		= S3C2410_UFCON_DEFAULT,
2717 	},
2718 };
2719 #define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
2720 #else
2721 #define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2722 #endif
2723 
2724 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2725 static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2726 	.info = &(struct s3c24xx_uart_info) {
2727 		.name		= "Samsung S3C6400 UART",
2728 		.type		= TYPE_S3C6400,
2729 		.port_type	= PORT_S3C6400,
2730 		.fifosize	= 64,
2731 		.has_divslot	= 1,
2732 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2733 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2734 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2735 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2736 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2737 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2738 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2739 		.num_clks	= 4,
2740 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2741 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2742 	},
2743 	.def_cfg = &(struct s3c2410_uartcfg) {
2744 		.ucon		= S3C2410_UCON_DEFAULT,
2745 		.ufcon		= S3C2410_UFCON_DEFAULT,
2746 	},
2747 };
2748 #define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
2749 #else
2750 #define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2751 #endif
2752 
2753 #ifdef CONFIG_CPU_S5PV210
2754 static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2755 	.info = &(struct s3c24xx_uart_info) {
2756 		.name		= "Samsung S5PV210 UART",
2757 		.type		= TYPE_S3C6400,
2758 		.port_type	= PORT_S3C6400,
2759 		.has_divslot	= 1,
2760 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2761 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2762 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2763 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2764 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2765 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2766 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2767 		.num_clks	= 2,
2768 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2769 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2770 	},
2771 	.def_cfg = &(struct s3c2410_uartcfg) {
2772 		.ucon		= S5PV210_UCON_DEFAULT,
2773 		.ufcon		= S5PV210_UFCON_DEFAULT,
2774 	},
2775 	.fifosize = { 256, 64, 16, 16 },
2776 };
2777 #define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
2778 #else
2779 #define S5PV210_SERIAL_DRV_DATA	(kernel_ulong_t)NULL
2780 #endif
2781 
2782 #if defined(CONFIG_ARCH_EXYNOS)
2783 #define EXYNOS_COMMON_SERIAL_DRV_DATA_USI(_has_usi)		\
2784 	.info = &(struct s3c24xx_uart_info) {			\
2785 		.name		= "Samsung Exynos UART",	\
2786 		.type		= TYPE_S3C6400,			\
2787 		.has_usi	= _has_usi,			\
2788 		.port_type	= PORT_S3C6400,			\
2789 		.has_divslot	= 1,				\
2790 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2791 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2792 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2793 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2794 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2795 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2796 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2797 		.num_clks	= 1,				\
2798 		.clksel_mask	= 0,				\
2799 		.clksel_shift	= 0,				\
2800 	},							\
2801 	.def_cfg = &(struct s3c2410_uartcfg) {			\
2802 		.ucon		= S5PV210_UCON_DEFAULT,		\
2803 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2804 		.has_fracval	= 1,				\
2805 	}							\
2806 
2807 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2808 	EXYNOS_COMMON_SERIAL_DRV_DATA_USI(0)
2809 
2810 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2811 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2812 	.fifosize = { 256, 64, 16, 16 },
2813 };
2814 
2815 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2816 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2817 	.fifosize = { 64, 256, 16, 256 },
2818 };
2819 
2820 static struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2821 	EXYNOS_COMMON_SERIAL_DRV_DATA_USI(1),
2822 	.fifosize = { 256, 64, 64, 64 },
2823 };
2824 
2825 #define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
2826 #define EXYNOS5433_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos5433_serial_drv_data)
2827 #define EXYNOS850_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos850_serial_drv_data)
2828 
2829 #else
2830 #define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)NULL)
2831 #define EXYNOS5433_SERIAL_DRV_DATA ((kernel_ulong_t)NULL)
2832 #define EXYNOS850_SERIAL_DRV_DATA ((kernel_ulong_t)NULL)
2833 #endif
2834 
2835 #ifdef CONFIG_ARCH_APPLE
2836 static struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2837 	.info = &(struct s3c24xx_uart_info) {
2838 		.name		= "Apple S5L UART",
2839 		.type		= TYPE_APPLE_S5L,
2840 		.port_type	= PORT_8250,
2841 		.fifosize	= 16,
2842 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2843 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2844 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2845 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2846 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2847 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2848 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2849 		.num_clks	= 1,
2850 		.clksel_mask	= 0,
2851 		.clksel_shift	= 0,
2852 	},
2853 	.def_cfg = &(struct s3c2410_uartcfg) {
2854 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2855 		.ufcon		= S3C2410_UFCON_DEFAULT,
2856 	},
2857 };
2858 #define S5L_SERIAL_DRV_DATA ((kernel_ulong_t)&s5l_serial_drv_data)
2859 #else
2860 #define S5L_SERIAL_DRV_DATA ((kernel_ulong_t)NULL)
2861 #endif
2862 
2863 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2864 	{
2865 		.name		= "s3c2410-uart",
2866 		.driver_data	= S3C2410_SERIAL_DRV_DATA,
2867 	}, {
2868 		.name		= "s3c2412-uart",
2869 		.driver_data	= S3C2412_SERIAL_DRV_DATA,
2870 	}, {
2871 		.name		= "s3c2440-uart",
2872 		.driver_data	= S3C2440_SERIAL_DRV_DATA,
2873 	}, {
2874 		.name		= "s3c6400-uart",
2875 		.driver_data	= S3C6400_SERIAL_DRV_DATA,
2876 	}, {
2877 		.name		= "s5pv210-uart",
2878 		.driver_data	= S5PV210_SERIAL_DRV_DATA,
2879 	}, {
2880 		.name		= "exynos4210-uart",
2881 		.driver_data	= EXYNOS4210_SERIAL_DRV_DATA,
2882 	}, {
2883 		.name		= "exynos5433-uart",
2884 		.driver_data	= EXYNOS5433_SERIAL_DRV_DATA,
2885 	}, {
2886 		.name		= "s5l-uart",
2887 		.driver_data	= S5L_SERIAL_DRV_DATA,
2888 	}, {
2889 		.name		= "exynos850-uart",
2890 		.driver_data	= EXYNOS850_SERIAL_DRV_DATA,
2891 	},
2892 	{ },
2893 };
2894 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2895 
2896 #ifdef CONFIG_OF
2897 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2898 	{ .compatible = "samsung,s3c2410-uart",
2899 		.data = (void *)S3C2410_SERIAL_DRV_DATA },
2900 	{ .compatible = "samsung,s3c2412-uart",
2901 		.data = (void *)S3C2412_SERIAL_DRV_DATA },
2902 	{ .compatible = "samsung,s3c2440-uart",
2903 		.data = (void *)S3C2440_SERIAL_DRV_DATA },
2904 	{ .compatible = "samsung,s3c6400-uart",
2905 		.data = (void *)S3C6400_SERIAL_DRV_DATA },
2906 	{ .compatible = "samsung,s5pv210-uart",
2907 		.data = (void *)S5PV210_SERIAL_DRV_DATA },
2908 	{ .compatible = "samsung,exynos4210-uart",
2909 		.data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
2910 	{ .compatible = "samsung,exynos5433-uart",
2911 		.data = (void *)EXYNOS5433_SERIAL_DRV_DATA },
2912 	{ .compatible = "apple,s5l-uart",
2913 		.data = (void *)S5L_SERIAL_DRV_DATA },
2914 	{ .compatible = "samsung,exynos850-uart",
2915 		.data = (void *)EXYNOS850_SERIAL_DRV_DATA },
2916 	{},
2917 };
2918 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2919 #endif
2920 
2921 static struct platform_driver samsung_serial_driver = {
2922 	.probe		= s3c24xx_serial_probe,
2923 	.remove		= s3c24xx_serial_remove,
2924 	.id_table	= s3c24xx_serial_driver_ids,
2925 	.driver		= {
2926 		.name	= "samsung-uart",
2927 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2928 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2929 	},
2930 };
2931 
2932 module_platform_driver(samsung_serial_driver);
2933 
2934 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2935 /*
2936  * Early console.
2937  */
2938 
2939 static void wr_reg_barrier(struct uart_port *port, u32 reg, u32 val)
2940 {
2941 	switch (port->iotype) {
2942 	case UPIO_MEM:
2943 		writeb(val, portaddr(port, reg));
2944 		break;
2945 	case UPIO_MEM32:
2946 		writel(val, portaddr(port, reg));
2947 		break;
2948 	}
2949 }
2950 
2951 struct samsung_early_console_data {
2952 	u32 txfull_mask;
2953 };
2954 
2955 static void samsung_early_busyuart(struct uart_port *port)
2956 {
2957 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2958 		;
2959 }
2960 
2961 static void samsung_early_busyuart_fifo(struct uart_port *port)
2962 {
2963 	struct samsung_early_console_data *data = port->private_data;
2964 
2965 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2966 		;
2967 }
2968 
2969 static void samsung_early_putc(struct uart_port *port, int c)
2970 {
2971 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2972 		samsung_early_busyuart_fifo(port);
2973 	else
2974 		samsung_early_busyuart(port);
2975 
2976 	wr_reg_barrier(port, S3C2410_UTXH, c);
2977 }
2978 
2979 static void samsung_early_write(struct console *con, const char *s,
2980 				unsigned int n)
2981 {
2982 	struct earlycon_device *dev = con->data;
2983 
2984 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2985 }
2986 
2987 static int __init samsung_early_console_setup(struct earlycon_device *device,
2988 					      const char *opt)
2989 {
2990 	if (!device->port.membase)
2991 		return -ENODEV;
2992 
2993 	device->con->write = samsung_early_write;
2994 	return 0;
2995 }
2996 
2997 /* S3C2410 */
2998 static struct samsung_early_console_data s3c2410_early_console_data = {
2999 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
3000 };
3001 
3002 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
3003 					      const char *opt)
3004 {
3005 	device->port.private_data = &s3c2410_early_console_data;
3006 	return samsung_early_console_setup(device, opt);
3007 }
3008 
3009 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
3010 			s3c2410_early_console_setup);
3011 
3012 /* S3C2412, S3C2440, S3C64xx */
3013 static struct samsung_early_console_data s3c2440_early_console_data = {
3014 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
3015 };
3016 
3017 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
3018 					      const char *opt)
3019 {
3020 	device->port.private_data = &s3c2440_early_console_data;
3021 	return samsung_early_console_setup(device, opt);
3022 }
3023 
3024 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
3025 			s3c2440_early_console_setup);
3026 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
3027 			s3c2440_early_console_setup);
3028 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
3029 			s3c2440_early_console_setup);
3030 
3031 /* S5PV210, Exynos */
3032 static struct samsung_early_console_data s5pv210_early_console_data = {
3033 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
3034 };
3035 
3036 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
3037 					      const char *opt)
3038 {
3039 	device->port.private_data = &s5pv210_early_console_data;
3040 	return samsung_early_console_setup(device, opt);
3041 }
3042 
3043 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
3044 			s5pv210_early_console_setup);
3045 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
3046 			s5pv210_early_console_setup);
3047 
3048 /* Apple S5L */
3049 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
3050 						const char *opt)
3051 {
3052 	/* Close enough to S3C2410 for earlycon... */
3053 	device->port.private_data = &s3c2410_early_console_data;
3054 
3055 #ifdef CONFIG_ARM64
3056 	/* ... but we need to override the existing fixmap entry as nGnRnE */
3057 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
3058 		     __pgprot(PROT_DEVICE_nGnRnE));
3059 #endif
3060 	return samsung_early_console_setup(device, opt);
3061 }
3062 
3063 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
3064 #endif
3065 
3066 MODULE_ALIAS("platform:samsung-uart");
3067 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
3068 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
3069 MODULE_LICENSE("GPL v2");
3070