xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision ae6385af)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Note on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/ioport.h>
29 #include <linux/io.h>
30 #include <linux/platform_device.h>
31 #include <linux/init.h>
32 #include <linux/sysrq.h>
33 #include <linux/console.h>
34 #include <linux/tty.h>
35 #include <linux/tty_flip.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
38 #include <linux/serial_s3c.h>
39 #include <linux/delay.h>
40 #include <linux/clk.h>
41 #include <linux/cpufreq.h>
42 #include <linux/of.h>
43 #include <asm/irq.h>
44 
45 /* UART name and device definitions */
46 
47 #define S3C24XX_SERIAL_NAME	"ttySAC"
48 #define S3C24XX_SERIAL_MAJOR	204
49 #define S3C24XX_SERIAL_MINOR	64
50 
51 #ifdef CONFIG_ARM64
52 #define UART_NR			12
53 #else
54 #define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
55 #endif
56 
57 #define S3C24XX_TX_PIO			1
58 #define S3C24XX_TX_DMA			2
59 #define S3C24XX_RX_PIO			1
60 #define S3C24XX_RX_DMA			2
61 
62 /* flag to ignore all characters coming in */
63 #define RXSTAT_DUMMY_READ (0x10000000)
64 
65 enum s3c24xx_port_type {
66 	TYPE_S3C24XX,
67 	TYPE_S3C6400,
68 	TYPE_APPLE_S5L,
69 };
70 
71 struct s3c24xx_uart_info {
72 	const char		*name;
73 	enum s3c24xx_port_type	type;
74 	unsigned int		port_type;
75 	unsigned int		fifosize;
76 	unsigned long		rx_fifomask;
77 	unsigned long		rx_fifoshift;
78 	unsigned long		rx_fifofull;
79 	unsigned long		tx_fifomask;
80 	unsigned long		tx_fifoshift;
81 	unsigned long		tx_fifofull;
82 	unsigned int		def_clk_sel;
83 	unsigned long		num_clks;
84 	unsigned long		clksel_mask;
85 	unsigned long		clksel_shift;
86 	unsigned long		ucon_mask;
87 
88 	/* uart port features */
89 
90 	unsigned int		has_divslot:1;
91 };
92 
93 struct s3c24xx_serial_drv_data {
94 	const struct s3c24xx_uart_info	info;
95 	const struct s3c2410_uartcfg	def_cfg;
96 	const unsigned int		fifosize[UART_NR];
97 };
98 
99 struct s3c24xx_uart_dma {
100 	unsigned int			rx_chan_id;
101 	unsigned int			tx_chan_id;
102 
103 	struct dma_slave_config		rx_conf;
104 	struct dma_slave_config		tx_conf;
105 
106 	struct dma_chan			*rx_chan;
107 	struct dma_chan			*tx_chan;
108 
109 	dma_addr_t			rx_addr;
110 	dma_addr_t			tx_addr;
111 
112 	dma_cookie_t			rx_cookie;
113 	dma_cookie_t			tx_cookie;
114 
115 	char				*rx_buf;
116 
117 	dma_addr_t			tx_transfer_addr;
118 
119 	size_t				rx_size;
120 	size_t				tx_size;
121 
122 	struct dma_async_tx_descriptor	*tx_desc;
123 	struct dma_async_tx_descriptor	*rx_desc;
124 
125 	int				tx_bytes_requested;
126 	int				rx_bytes_requested;
127 };
128 
129 struct s3c24xx_uart_port {
130 	unsigned char			rx_claimed;
131 	unsigned char			tx_claimed;
132 	unsigned char			rx_enabled;
133 	unsigned char			tx_enabled;
134 	unsigned int			pm_level;
135 	unsigned long			baudclk_rate;
136 	unsigned int			min_dma_size;
137 
138 	unsigned int			rx_irq;
139 	unsigned int			tx_irq;
140 
141 	unsigned int			tx_in_progress;
142 	unsigned int			tx_mode;
143 	unsigned int			rx_mode;
144 
145 	const struct s3c24xx_uart_info	*info;
146 	struct clk			*clk;
147 	struct clk			*baudclk;
148 	struct uart_port		port;
149 	const struct s3c24xx_serial_drv_data	*drv_data;
150 
151 	/* reference to platform data */
152 	const struct s3c2410_uartcfg	*cfg;
153 
154 	struct s3c24xx_uart_dma		*dma;
155 };
156 
157 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
158 
159 /* conversion functions */
160 
161 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
162 
163 /* register access controls */
164 
165 #define portaddr(port, reg) ((port)->membase + (reg))
166 #define portaddrl(port, reg) \
167 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
168 
169 static u32 rd_reg(const struct uart_port *port, u32 reg)
170 {
171 	switch (port->iotype) {
172 	case UPIO_MEM:
173 		return readb_relaxed(portaddr(port, reg));
174 	case UPIO_MEM32:
175 		return readl_relaxed(portaddr(port, reg));
176 	default:
177 		return 0;
178 	}
179 	return 0;
180 }
181 
182 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
183 
184 static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
185 {
186 	switch (port->iotype) {
187 	case UPIO_MEM:
188 		writeb_relaxed(val, portaddr(port, reg));
189 		break;
190 	case UPIO_MEM32:
191 		writel_relaxed(val, portaddr(port, reg));
192 		break;
193 	}
194 }
195 
196 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
197 
198 /* Byte-order aware bit setting/clearing functions. */
199 
200 static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
201 				   unsigned int reg)
202 {
203 	unsigned long flags;
204 	u32 val;
205 
206 	local_irq_save(flags);
207 	val = rd_regl(port, reg);
208 	val |= (1 << idx);
209 	wr_regl(port, reg, val);
210 	local_irq_restore(flags);
211 }
212 
213 static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
214 				     unsigned int reg)
215 {
216 	unsigned long flags;
217 	u32 val;
218 
219 	local_irq_save(flags);
220 	val = rd_regl(port, reg);
221 	val &= ~(1 << idx);
222 	wr_regl(port, reg, val);
223 	local_irq_restore(flags);
224 }
225 
226 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
227 {
228 	return container_of(port, struct s3c24xx_uart_port, port);
229 }
230 
231 /* translate a port to the device name */
232 
233 static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
234 {
235 	return to_platform_device(port->dev)->name;
236 }
237 
238 static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
239 {
240 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
241 }
242 
243 static void s3c24xx_serial_rx_enable(struct uart_port *port)
244 {
245 	struct s3c24xx_uart_port *ourport = to_ourport(port);
246 	unsigned long flags;
247 	unsigned int ucon, ufcon;
248 	int count = 10000;
249 
250 	spin_lock_irqsave(&port->lock, flags);
251 
252 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
253 		udelay(100);
254 
255 	ufcon = rd_regl(port, S3C2410_UFCON);
256 	ufcon |= S3C2410_UFCON_RESETRX;
257 	wr_regl(port, S3C2410_UFCON, ufcon);
258 
259 	ucon = rd_regl(port, S3C2410_UCON);
260 	ucon |= S3C2410_UCON_RXIRQMODE;
261 	wr_regl(port, S3C2410_UCON, ucon);
262 
263 	ourport->rx_enabled = 1;
264 	spin_unlock_irqrestore(&port->lock, flags);
265 }
266 
267 static void s3c24xx_serial_rx_disable(struct uart_port *port)
268 {
269 	struct s3c24xx_uart_port *ourport = to_ourport(port);
270 	unsigned long flags;
271 	unsigned int ucon;
272 
273 	spin_lock_irqsave(&port->lock, flags);
274 
275 	ucon = rd_regl(port, S3C2410_UCON);
276 	ucon &= ~S3C2410_UCON_RXIRQMODE;
277 	wr_regl(port, S3C2410_UCON, ucon);
278 
279 	ourport->rx_enabled = 0;
280 	spin_unlock_irqrestore(&port->lock, flags);
281 }
282 
283 static void s3c24xx_serial_stop_tx(struct uart_port *port)
284 {
285 	struct s3c24xx_uart_port *ourport = to_ourport(port);
286 	struct s3c24xx_uart_dma *dma = ourport->dma;
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 		uart_xmit_advance(port, count);
315 	}
316 
317 	ourport->tx_enabled = 0;
318 	ourport->tx_in_progress = 0;
319 
320 	if (port->flags & UPF_CONS_FLOW)
321 		s3c24xx_serial_rx_enable(port);
322 
323 	ourport->tx_mode = 0;
324 }
325 
326 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
327 
328 static void s3c24xx_serial_tx_dma_complete(void *args)
329 {
330 	struct s3c24xx_uart_port *ourport = args;
331 	struct uart_port *port = &ourport->port;
332 	struct circ_buf *xmit = &port->state->xmit;
333 	struct s3c24xx_uart_dma *dma = ourport->dma;
334 	struct dma_tx_state state;
335 	unsigned long flags;
336 	int count;
337 
338 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
339 	count = dma->tx_bytes_requested - state.residue;
340 	async_tx_ack(dma->tx_desc);
341 
342 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
343 				dma->tx_transfer_addr, dma->tx_size,
344 				DMA_TO_DEVICE);
345 
346 	spin_lock_irqsave(&port->lock, flags);
347 
348 	uart_xmit_advance(port, count);
349 	ourport->tx_in_progress = 0;
350 
351 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
352 		uart_write_wakeup(port);
353 
354 	s3c24xx_serial_start_next_tx(ourport);
355 	spin_unlock_irqrestore(&port->lock, flags);
356 }
357 
358 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
359 {
360 	const struct uart_port *port = &ourport->port;
361 	u32 ucon;
362 
363 	/* Mask Tx interrupt */
364 	switch (ourport->info->type) {
365 	case TYPE_S3C6400:
366 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
367 		break;
368 	case TYPE_APPLE_S5L:
369 		WARN_ON(1); // No DMA
370 		break;
371 	default:
372 		disable_irq_nosync(ourport->tx_irq);
373 		break;
374 	}
375 
376 	/* Enable tx dma mode */
377 	ucon = rd_regl(port, S3C2410_UCON);
378 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
379 	ucon |= S3C64XX_UCON_TXBURST_1;
380 	ucon |= S3C64XX_UCON_TXMODE_DMA;
381 	wr_regl(port,  S3C2410_UCON, ucon);
382 
383 	ourport->tx_mode = S3C24XX_TX_DMA;
384 }
385 
386 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
387 {
388 	const struct uart_port *port = &ourport->port;
389 	u32 ucon, ufcon;
390 
391 	/* Set ufcon txtrig */
392 	ourport->tx_in_progress = S3C24XX_TX_PIO;
393 	ufcon = rd_regl(port, S3C2410_UFCON);
394 	wr_regl(port,  S3C2410_UFCON, ufcon);
395 
396 	/* Enable tx pio mode */
397 	ucon = rd_regl(port, S3C2410_UCON);
398 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
399 	ucon |= S3C64XX_UCON_TXMODE_CPU;
400 	wr_regl(port,  S3C2410_UCON, ucon);
401 
402 	/* Unmask Tx interrupt */
403 	switch (ourport->info->type) {
404 	case TYPE_S3C6400:
405 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
406 				  S3C64XX_UINTM);
407 		break;
408 	case TYPE_APPLE_S5L:
409 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
410 		wr_regl(port, S3C2410_UCON, ucon);
411 		break;
412 	default:
413 		enable_irq(ourport->tx_irq);
414 		break;
415 	}
416 
417 	ourport->tx_mode = S3C24XX_TX_PIO;
418 
419 	/*
420 	 * The Apple version only has edge triggered TX IRQs, so we need
421 	 * to kick off the process by sending some characters here.
422 	 */
423 	if (ourport->info->type == TYPE_APPLE_S5L)
424 		s3c24xx_serial_tx_chars(ourport);
425 }
426 
427 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
428 {
429 	if (ourport->tx_mode != S3C24XX_TX_PIO)
430 		enable_tx_pio(ourport);
431 }
432 
433 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
434 				      unsigned int count)
435 {
436 	struct uart_port *port = &ourport->port;
437 	struct circ_buf *xmit = &port->state->xmit;
438 	struct s3c24xx_uart_dma *dma = ourport->dma;
439 
440 	if (ourport->tx_mode != S3C24XX_TX_DMA)
441 		enable_tx_dma(ourport);
442 
443 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
444 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
445 
446 	dma_sync_single_for_device(dma->tx_chan->device->dev,
447 				   dma->tx_transfer_addr, dma->tx_size,
448 				   DMA_TO_DEVICE);
449 
450 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
451 				dma->tx_transfer_addr, dma->tx_size,
452 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
453 	if (!dma->tx_desc) {
454 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
455 		return -EIO;
456 	}
457 
458 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
459 	dma->tx_desc->callback_param = ourport;
460 	dma->tx_bytes_requested = dma->tx_size;
461 
462 	ourport->tx_in_progress = S3C24XX_TX_DMA;
463 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
464 	dma_async_issue_pending(dma->tx_chan);
465 	return 0;
466 }
467 
468 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
469 {
470 	struct uart_port *port = &ourport->port;
471 	struct circ_buf *xmit = &port->state->xmit;
472 	unsigned long count;
473 
474 	/* Get data size up to the end of buffer */
475 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
476 
477 	if (!count) {
478 		s3c24xx_serial_stop_tx(port);
479 		return;
480 	}
481 
482 	if (!ourport->dma || !ourport->dma->tx_chan ||
483 	    count < ourport->min_dma_size ||
484 	    xmit->tail & (dma_get_cache_alignment() - 1))
485 		s3c24xx_serial_start_tx_pio(ourport);
486 	else
487 		s3c24xx_serial_start_tx_dma(ourport, count);
488 }
489 
490 static void s3c24xx_serial_start_tx(struct uart_port *port)
491 {
492 	struct s3c24xx_uart_port *ourport = to_ourport(port);
493 	struct circ_buf *xmit = &port->state->xmit;
494 
495 	if (!ourport->tx_enabled) {
496 		if (port->flags & UPF_CONS_FLOW)
497 			s3c24xx_serial_rx_disable(port);
498 
499 		ourport->tx_enabled = 1;
500 		if (!ourport->dma || !ourport->dma->tx_chan)
501 			s3c24xx_serial_start_tx_pio(ourport);
502 	}
503 
504 	if (ourport->dma && ourport->dma->tx_chan) {
505 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
506 			s3c24xx_serial_start_next_tx(ourport);
507 	}
508 }
509 
510 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
511 		struct tty_port *tty, int count)
512 {
513 	struct s3c24xx_uart_dma *dma = ourport->dma;
514 	int copied;
515 
516 	if (!count)
517 		return;
518 
519 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
520 				dma->rx_size, DMA_FROM_DEVICE);
521 
522 	ourport->port.icount.rx += count;
523 	if (!tty) {
524 		dev_err(ourport->port.dev, "No tty port\n");
525 		return;
526 	}
527 	copied = tty_insert_flip_string(tty,
528 			((unsigned char *)(ourport->dma->rx_buf)), count);
529 	if (copied != count) {
530 		WARN_ON(1);
531 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
532 	}
533 }
534 
535 static void s3c24xx_serial_stop_rx(struct uart_port *port)
536 {
537 	struct s3c24xx_uart_port *ourport = to_ourport(port);
538 	struct s3c24xx_uart_dma *dma = ourport->dma;
539 	struct tty_port *t = &port->state->port;
540 	struct dma_tx_state state;
541 	enum dma_status dma_status;
542 	unsigned int received;
543 
544 	if (ourport->rx_enabled) {
545 		dev_dbg(port->dev, "stopping rx\n");
546 		switch (ourport->info->type) {
547 		case TYPE_S3C6400:
548 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
549 					S3C64XX_UINTM);
550 			break;
551 		case TYPE_APPLE_S5L:
552 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
553 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
554 			break;
555 		default:
556 			disable_irq_nosync(ourport->rx_irq);
557 			break;
558 		}
559 		ourport->rx_enabled = 0;
560 	}
561 	if (dma && dma->rx_chan) {
562 		dmaengine_pause(dma->tx_chan);
563 		dma_status = dmaengine_tx_status(dma->rx_chan,
564 				dma->rx_cookie, &state);
565 		if (dma_status == DMA_IN_PROGRESS ||
566 			dma_status == DMA_PAUSED) {
567 			received = dma->rx_bytes_requested - state.residue;
568 			dmaengine_terminate_all(dma->rx_chan);
569 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
570 		}
571 	}
572 }
573 
574 static inline const struct s3c24xx_uart_info
575 	*s3c24xx_port_to_info(struct uart_port *port)
576 {
577 	return to_ourport(port)->info;
578 }
579 
580 static inline const struct s3c2410_uartcfg
581 	*s3c24xx_port_to_cfg(const struct uart_port *port)
582 {
583 	const struct s3c24xx_uart_port *ourport;
584 
585 	if (port->dev == NULL)
586 		return NULL;
587 
588 	ourport = container_of(port, struct s3c24xx_uart_port, port);
589 	return ourport->cfg;
590 }
591 
592 static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
593 				     unsigned long ufstat)
594 {
595 	const struct s3c24xx_uart_info *info = ourport->info;
596 
597 	if (ufstat & info->rx_fifofull)
598 		return ourport->port.fifosize;
599 
600 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
601 }
602 
603 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
604 static void s3c24xx_serial_rx_dma_complete(void *args)
605 {
606 	struct s3c24xx_uart_port *ourport = args;
607 	struct uart_port *port = &ourport->port;
608 
609 	struct s3c24xx_uart_dma *dma = ourport->dma;
610 	struct tty_port *t = &port->state->port;
611 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
612 
613 	struct dma_tx_state state;
614 	unsigned long flags;
615 	int received;
616 
617 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
618 	received  = dma->rx_bytes_requested - state.residue;
619 	async_tx_ack(dma->rx_desc);
620 
621 	spin_lock_irqsave(&port->lock, flags);
622 
623 	if (received)
624 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
625 
626 	if (tty) {
627 		tty_flip_buffer_push(t);
628 		tty_kref_put(tty);
629 	}
630 
631 	s3c64xx_start_rx_dma(ourport);
632 
633 	spin_unlock_irqrestore(&port->lock, flags);
634 }
635 
636 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
637 {
638 	struct s3c24xx_uart_dma *dma = ourport->dma;
639 
640 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
641 				   dma->rx_size, DMA_FROM_DEVICE);
642 
643 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
644 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
645 				DMA_PREP_INTERRUPT);
646 	if (!dma->rx_desc) {
647 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
648 		return;
649 	}
650 
651 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
652 	dma->rx_desc->callback_param = ourport;
653 	dma->rx_bytes_requested = dma->rx_size;
654 
655 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
656 	dma_async_issue_pending(dma->rx_chan);
657 }
658 
659 /* ? - where has parity gone?? */
660 #define S3C2410_UERSTAT_PARITY (0x1000)
661 
662 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
663 {
664 	struct uart_port *port = &ourport->port;
665 	unsigned int ucon;
666 
667 	/* set Rx mode to DMA mode */
668 	ucon = rd_regl(port, S3C2410_UCON);
669 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
670 			S3C64XX_UCON_TIMEOUT_MASK |
671 			S3C64XX_UCON_EMPTYINT_EN |
672 			S3C64XX_UCON_DMASUS_EN |
673 			S3C64XX_UCON_TIMEOUT_EN |
674 			S3C64XX_UCON_RXMODE_MASK);
675 	ucon |= S3C64XX_UCON_RXBURST_1 |
676 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
677 			S3C64XX_UCON_EMPTYINT_EN |
678 			S3C64XX_UCON_TIMEOUT_EN |
679 			S3C64XX_UCON_RXMODE_DMA;
680 	wr_regl(port, S3C2410_UCON, ucon);
681 
682 	ourport->rx_mode = S3C24XX_RX_DMA;
683 }
684 
685 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
686 {
687 	struct uart_port *port = &ourport->port;
688 	unsigned int ucon;
689 
690 	/* set Rx mode to DMA mode */
691 	ucon = rd_regl(port, S3C2410_UCON);
692 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
693 	ucon |= S3C64XX_UCON_RXMODE_CPU;
694 
695 	/* Apple types use these bits for IRQ masks */
696 	if (ourport->info->type != TYPE_APPLE_S5L) {
697 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
698 				S3C64XX_UCON_EMPTYINT_EN |
699 				S3C64XX_UCON_DMASUS_EN |
700 				S3C64XX_UCON_TIMEOUT_EN);
701 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
702 				S3C64XX_UCON_TIMEOUT_EN;
703 	}
704 	wr_regl(port, S3C2410_UCON, ucon);
705 
706 	ourport->rx_mode = S3C24XX_RX_PIO;
707 }
708 
709 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
710 
711 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
712 {
713 	unsigned int utrstat, received;
714 	struct s3c24xx_uart_port *ourport = dev_id;
715 	struct uart_port *port = &ourport->port;
716 	struct s3c24xx_uart_dma *dma = ourport->dma;
717 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
718 	struct tty_port *t = &port->state->port;
719 	struct dma_tx_state state;
720 
721 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
722 	rd_regl(port, S3C2410_UFSTAT);
723 
724 	spin_lock(&port->lock);
725 
726 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
727 		s3c64xx_start_rx_dma(ourport);
728 		if (ourport->rx_mode == S3C24XX_RX_PIO)
729 			enable_rx_dma(ourport);
730 		goto finish;
731 	}
732 
733 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
734 		dmaengine_pause(dma->rx_chan);
735 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
736 		dmaengine_terminate_all(dma->rx_chan);
737 		received = dma->rx_bytes_requested - state.residue;
738 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
739 
740 		enable_rx_pio(ourport);
741 	}
742 
743 	s3c24xx_serial_rx_drain_fifo(ourport);
744 
745 	if (tty) {
746 		tty_flip_buffer_push(t);
747 		tty_kref_put(tty);
748 	}
749 
750 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
751 
752 finish:
753 	spin_unlock(&port->lock);
754 
755 	return IRQ_HANDLED;
756 }
757 
758 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
759 {
760 	struct uart_port *port = &ourport->port;
761 	unsigned int ufcon, ch, flag, ufstat, uerstat;
762 	unsigned int fifocnt = 0;
763 	int max_count = port->fifosize;
764 
765 	while (max_count-- > 0) {
766 		/*
767 		 * Receive all characters known to be in FIFO
768 		 * before reading FIFO level again
769 		 */
770 		if (fifocnt == 0) {
771 			ufstat = rd_regl(port, S3C2410_UFSTAT);
772 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
773 			if (fifocnt == 0)
774 				break;
775 		}
776 		fifocnt--;
777 
778 		uerstat = rd_regl(port, S3C2410_UERSTAT);
779 		ch = rd_reg(port, S3C2410_URXH);
780 
781 		if (port->flags & UPF_CONS_FLOW) {
782 			int txe = s3c24xx_serial_txempty_nofifo(port);
783 
784 			if (ourport->rx_enabled) {
785 				if (!txe) {
786 					ourport->rx_enabled = 0;
787 					continue;
788 				}
789 			} else {
790 				if (txe) {
791 					ufcon = rd_regl(port, S3C2410_UFCON);
792 					ufcon |= S3C2410_UFCON_RESETRX;
793 					wr_regl(port, S3C2410_UFCON, ufcon);
794 					ourport->rx_enabled = 1;
795 					return;
796 				}
797 				continue;
798 			}
799 		}
800 
801 		/* insert the character into the buffer */
802 
803 		flag = TTY_NORMAL;
804 		port->icount.rx++;
805 
806 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
807 			dev_dbg(port->dev,
808 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
809 				ch, uerstat);
810 
811 			/* check for break */
812 			if (uerstat & S3C2410_UERSTAT_BREAK) {
813 				dev_dbg(port->dev, "break!\n");
814 				port->icount.brk++;
815 				if (uart_handle_break(port))
816 					continue; /* Ignore character */
817 			}
818 
819 			if (uerstat & S3C2410_UERSTAT_FRAME)
820 				port->icount.frame++;
821 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
822 				port->icount.overrun++;
823 
824 			uerstat &= port->read_status_mask;
825 
826 			if (uerstat & S3C2410_UERSTAT_BREAK)
827 				flag = TTY_BREAK;
828 			else if (uerstat & S3C2410_UERSTAT_PARITY)
829 				flag = TTY_PARITY;
830 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
831 					    S3C2410_UERSTAT_OVERRUN))
832 				flag = TTY_FRAME;
833 		}
834 
835 		if (uart_handle_sysrq_char(port, ch))
836 			continue; /* Ignore character */
837 
838 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
839 				 ch, flag);
840 	}
841 
842 	tty_flip_buffer_push(&port->state->port);
843 }
844 
845 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
846 {
847 	struct s3c24xx_uart_port *ourport = dev_id;
848 	struct uart_port *port = &ourport->port;
849 
850 	spin_lock(&port->lock);
851 	s3c24xx_serial_rx_drain_fifo(ourport);
852 	spin_unlock(&port->lock);
853 
854 	return IRQ_HANDLED;
855 }
856 
857 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
858 {
859 	struct s3c24xx_uart_port *ourport = dev_id;
860 
861 	if (ourport->dma && ourport->dma->rx_chan)
862 		return s3c24xx_serial_rx_chars_dma(dev_id);
863 	return s3c24xx_serial_rx_chars_pio(dev_id);
864 }
865 
866 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
867 {
868 	struct uart_port *port = &ourport->port;
869 	struct circ_buf *xmit = &port->state->xmit;
870 	int count, dma_count = 0;
871 
872 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
873 
874 	if (ourport->dma && ourport->dma->tx_chan &&
875 	    count >= ourport->min_dma_size) {
876 		int align = dma_get_cache_alignment() -
877 			(xmit->tail & (dma_get_cache_alignment() - 1));
878 		if (count - align >= ourport->min_dma_size) {
879 			dma_count = count - align;
880 			count = align;
881 		}
882 	}
883 
884 	if (port->x_char) {
885 		wr_reg(port, S3C2410_UTXH, port->x_char);
886 		port->icount.tx++;
887 		port->x_char = 0;
888 		return;
889 	}
890 
891 	/* if there isn't anything more to transmit, or the uart is now
892 	 * stopped, disable the uart and exit
893 	 */
894 
895 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
896 		s3c24xx_serial_stop_tx(port);
897 		return;
898 	}
899 
900 	/* try and drain the buffer... */
901 
902 	if (count > port->fifosize) {
903 		count = port->fifosize;
904 		dma_count = 0;
905 	}
906 
907 	while (!uart_circ_empty(xmit) && count > 0) {
908 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
909 			break;
910 
911 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
912 		uart_xmit_advance(port, 1);
913 		count--;
914 	}
915 
916 	if (!count && dma_count) {
917 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
918 		return;
919 	}
920 
921 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
922 		uart_write_wakeup(port);
923 
924 	if (uart_circ_empty(xmit))
925 		s3c24xx_serial_stop_tx(port);
926 }
927 
928 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
929 {
930 	struct s3c24xx_uart_port *ourport = id;
931 	struct uart_port *port = &ourport->port;
932 
933 	spin_lock(&port->lock);
934 
935 	s3c24xx_serial_tx_chars(ourport);
936 
937 	spin_unlock(&port->lock);
938 	return IRQ_HANDLED;
939 }
940 
941 /* interrupt handler for s3c64xx and later SoC's.*/
942 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
943 {
944 	const struct s3c24xx_uart_port *ourport = id;
945 	const struct uart_port *port = &ourport->port;
946 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
947 	irqreturn_t ret = IRQ_HANDLED;
948 
949 	if (pend & S3C64XX_UINTM_RXD_MSK) {
950 		ret = s3c24xx_serial_rx_irq(irq, id);
951 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
952 	}
953 	if (pend & S3C64XX_UINTM_TXD_MSK) {
954 		ret = s3c24xx_serial_tx_irq(irq, id);
955 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
956 	}
957 	return ret;
958 }
959 
960 /* interrupt handler for Apple SoC's.*/
961 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
962 {
963 	const struct s3c24xx_uart_port *ourport = id;
964 	const struct uart_port *port = &ourport->port;
965 	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
966 	irqreturn_t ret = IRQ_NONE;
967 
968 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
969 		wr_regl(port, S3C2410_UTRSTAT,
970 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
971 		ret = s3c24xx_serial_rx_irq(irq, id);
972 	}
973 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
974 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
975 		ret = s3c24xx_serial_tx_irq(irq, id);
976 	}
977 
978 	return ret;
979 }
980 
981 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
982 {
983 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
984 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
985 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
986 
987 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
988 		if ((ufstat & info->tx_fifomask) != 0 ||
989 		    (ufstat & info->tx_fifofull))
990 			return 0;
991 
992 		return 1;
993 	}
994 
995 	return s3c24xx_serial_txempty_nofifo(port);
996 }
997 
998 /* no modem control lines */
999 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1000 {
1001 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
1002 
1003 	if (umstat & S3C2410_UMSTAT_CTS)
1004 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1005 	else
1006 		return TIOCM_CAR | TIOCM_DSR;
1007 }
1008 
1009 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1010 {
1011 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
1012 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
1013 
1014 	if (mctrl & TIOCM_RTS)
1015 		umcon |= S3C2410_UMCOM_RTS_LOW;
1016 	else
1017 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1018 
1019 	wr_regl(port, S3C2410_UMCON, umcon);
1020 
1021 	if (mctrl & TIOCM_LOOP)
1022 		ucon |= S3C2410_UCON_LOOPBACK;
1023 	else
1024 		ucon &= ~S3C2410_UCON_LOOPBACK;
1025 
1026 	wr_regl(port, S3C2410_UCON, ucon);
1027 }
1028 
1029 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1030 {
1031 	unsigned long flags;
1032 	unsigned int ucon;
1033 
1034 	spin_lock_irqsave(&port->lock, flags);
1035 
1036 	ucon = rd_regl(port, S3C2410_UCON);
1037 
1038 	if (break_state)
1039 		ucon |= S3C2410_UCON_SBREAK;
1040 	else
1041 		ucon &= ~S3C2410_UCON_SBREAK;
1042 
1043 	wr_regl(port, S3C2410_UCON, ucon);
1044 
1045 	spin_unlock_irqrestore(&port->lock, flags);
1046 }
1047 
1048 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1049 {
1050 	struct s3c24xx_uart_dma	*dma = p->dma;
1051 	struct dma_slave_caps dma_caps;
1052 	const char *reason = NULL;
1053 	int ret;
1054 
1055 	/* Default slave configuration parameters */
1056 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1057 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1058 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1059 	dma->rx_conf.src_maxburst	= 1;
1060 
1061 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1062 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1063 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1064 	dma->tx_conf.dst_maxburst	= 1;
1065 
1066 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1067 
1068 	if (IS_ERR(dma->rx_chan)) {
1069 		reason = "DMA RX channel request failed";
1070 		ret = PTR_ERR(dma->rx_chan);
1071 		goto err_warn;
1072 	}
1073 
1074 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1075 	if (ret < 0 ||
1076 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1077 		reason = "insufficient DMA RX engine capabilities";
1078 		ret = -EOPNOTSUPP;
1079 		goto err_release_rx;
1080 	}
1081 
1082 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1083 
1084 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1085 	if (IS_ERR(dma->tx_chan)) {
1086 		reason = "DMA TX channel request failed";
1087 		ret = PTR_ERR(dma->tx_chan);
1088 		goto err_release_rx;
1089 	}
1090 
1091 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1092 	if (ret < 0 ||
1093 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1094 		reason = "insufficient DMA TX engine capabilities";
1095 		ret = -EOPNOTSUPP;
1096 		goto err_release_tx;
1097 	}
1098 
1099 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1100 
1101 	/* RX buffer */
1102 	dma->rx_size = PAGE_SIZE;
1103 
1104 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1105 	if (!dma->rx_buf) {
1106 		ret = -ENOMEM;
1107 		goto err_release_tx;
1108 	}
1109 
1110 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1111 				      dma->rx_size, DMA_FROM_DEVICE);
1112 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1113 		reason = "DMA mapping error for RX buffer";
1114 		ret = -EIO;
1115 		goto err_free_rx;
1116 	}
1117 
1118 	/* TX buffer */
1119 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1120 				      p->port.state->xmit.buf, UART_XMIT_SIZE,
1121 				      DMA_TO_DEVICE);
1122 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1123 		reason = "DMA mapping error for TX buffer";
1124 		ret = -EIO;
1125 		goto err_unmap_rx;
1126 	}
1127 
1128 	return 0;
1129 
1130 err_unmap_rx:
1131 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1132 			 dma->rx_size, DMA_FROM_DEVICE);
1133 err_free_rx:
1134 	kfree(dma->rx_buf);
1135 err_release_tx:
1136 	dma_release_channel(dma->tx_chan);
1137 err_release_rx:
1138 	dma_release_channel(dma->rx_chan);
1139 err_warn:
1140 	if (reason)
1141 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1142 	return ret;
1143 }
1144 
1145 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1146 {
1147 	struct s3c24xx_uart_dma	*dma = p->dma;
1148 
1149 	if (dma->rx_chan) {
1150 		dmaengine_terminate_all(dma->rx_chan);
1151 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1152 				 dma->rx_size, DMA_FROM_DEVICE);
1153 		kfree(dma->rx_buf);
1154 		dma_release_channel(dma->rx_chan);
1155 		dma->rx_chan = NULL;
1156 	}
1157 
1158 	if (dma->tx_chan) {
1159 		dmaengine_terminate_all(dma->tx_chan);
1160 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1161 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1162 		dma_release_channel(dma->tx_chan);
1163 		dma->tx_chan = NULL;
1164 	}
1165 }
1166 
1167 static void s3c24xx_serial_shutdown(struct uart_port *port)
1168 {
1169 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1170 
1171 	if (ourport->tx_claimed) {
1172 		free_irq(ourport->tx_irq, ourport);
1173 		ourport->tx_enabled = 0;
1174 		ourport->tx_claimed = 0;
1175 		ourport->tx_mode = 0;
1176 	}
1177 
1178 	if (ourport->rx_claimed) {
1179 		free_irq(ourport->rx_irq, ourport);
1180 		ourport->rx_claimed = 0;
1181 		ourport->rx_enabled = 0;
1182 	}
1183 
1184 	if (ourport->dma)
1185 		s3c24xx_serial_release_dma(ourport);
1186 
1187 	ourport->tx_in_progress = 0;
1188 }
1189 
1190 static void s3c64xx_serial_shutdown(struct uart_port *port)
1191 {
1192 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1193 
1194 	ourport->tx_enabled = 0;
1195 	ourport->tx_mode = 0;
1196 	ourport->rx_enabled = 0;
1197 
1198 	free_irq(port->irq, ourport);
1199 
1200 	wr_regl(port, S3C64XX_UINTP, 0xf);
1201 	wr_regl(port, S3C64XX_UINTM, 0xf);
1202 
1203 	if (ourport->dma)
1204 		s3c24xx_serial_release_dma(ourport);
1205 
1206 	ourport->tx_in_progress = 0;
1207 }
1208 
1209 static void apple_s5l_serial_shutdown(struct uart_port *port)
1210 {
1211 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1212 
1213 	unsigned int ucon;
1214 
1215 	ucon = rd_regl(port, S3C2410_UCON);
1216 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1217 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1218 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1219 	wr_regl(port, S3C2410_UCON, ucon);
1220 
1221 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1222 
1223 	free_irq(port->irq, ourport);
1224 
1225 	ourport->tx_enabled = 0;
1226 	ourport->tx_mode = 0;
1227 	ourport->rx_enabled = 0;
1228 
1229 	if (ourport->dma)
1230 		s3c24xx_serial_release_dma(ourport);
1231 
1232 	ourport->tx_in_progress = 0;
1233 }
1234 
1235 static int s3c24xx_serial_startup(struct uart_port *port)
1236 {
1237 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1238 	int ret;
1239 
1240 	ourport->rx_enabled = 1;
1241 
1242 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
1243 			  s3c24xx_serial_portname(port), ourport);
1244 
1245 	if (ret != 0) {
1246 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1247 		return ret;
1248 	}
1249 
1250 	ourport->rx_claimed = 1;
1251 
1252 	dev_dbg(port->dev, "requesting tx irq...\n");
1253 
1254 	ourport->tx_enabled = 1;
1255 
1256 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
1257 			  s3c24xx_serial_portname(port), ourport);
1258 
1259 	if (ret) {
1260 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1261 		goto err;
1262 	}
1263 
1264 	ourport->tx_claimed = 1;
1265 
1266 	/* the port reset code should have done the correct
1267 	 * register setup for the port controls
1268 	 */
1269 
1270 	return ret;
1271 
1272 err:
1273 	s3c24xx_serial_shutdown(port);
1274 	return ret;
1275 }
1276 
1277 static int s3c64xx_serial_startup(struct uart_port *port)
1278 {
1279 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1280 	unsigned long flags;
1281 	unsigned int ufcon;
1282 	int ret;
1283 
1284 	wr_regl(port, S3C64XX_UINTM, 0xf);
1285 	if (ourport->dma) {
1286 		ret = s3c24xx_serial_request_dma(ourport);
1287 		if (ret < 0) {
1288 			devm_kfree(port->dev, ourport->dma);
1289 			ourport->dma = NULL;
1290 		}
1291 	}
1292 
1293 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1294 			  s3c24xx_serial_portname(port), ourport);
1295 	if (ret) {
1296 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1297 		return ret;
1298 	}
1299 
1300 	/* For compatibility with s3c24xx Soc's */
1301 	ourport->rx_enabled = 1;
1302 	ourport->tx_enabled = 0;
1303 
1304 	spin_lock_irqsave(&port->lock, flags);
1305 
1306 	ufcon = rd_regl(port, S3C2410_UFCON);
1307 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1308 	if (!uart_console(port))
1309 		ufcon |= S3C2410_UFCON_RESETTX;
1310 	wr_regl(port, S3C2410_UFCON, ufcon);
1311 
1312 	enable_rx_pio(ourport);
1313 
1314 	spin_unlock_irqrestore(&port->lock, flags);
1315 
1316 	/* Enable Rx Interrupt */
1317 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1318 
1319 	return ret;
1320 }
1321 
1322 static int apple_s5l_serial_startup(struct uart_port *port)
1323 {
1324 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1325 	unsigned long flags;
1326 	unsigned int ufcon;
1327 	int ret;
1328 
1329 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1330 
1331 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1332 			  s3c24xx_serial_portname(port), ourport);
1333 	if (ret) {
1334 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1335 		return ret;
1336 	}
1337 
1338 	/* For compatibility with s3c24xx Soc's */
1339 	ourport->rx_enabled = 1;
1340 	ourport->tx_enabled = 0;
1341 
1342 	spin_lock_irqsave(&port->lock, flags);
1343 
1344 	ufcon = rd_regl(port, S3C2410_UFCON);
1345 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1346 	if (!uart_console(port))
1347 		ufcon |= S3C2410_UFCON_RESETTX;
1348 	wr_regl(port, S3C2410_UFCON, ufcon);
1349 
1350 	enable_rx_pio(ourport);
1351 
1352 	spin_unlock_irqrestore(&port->lock, flags);
1353 
1354 	/* Enable Rx Interrupt */
1355 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1356 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1357 
1358 	return ret;
1359 }
1360 
1361 /* power power management control */
1362 
1363 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1364 			      unsigned int old)
1365 {
1366 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1367 	int timeout = 10000;
1368 
1369 	ourport->pm_level = level;
1370 
1371 	switch (level) {
1372 	case 3:
1373 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1374 			udelay(100);
1375 
1376 		if (!IS_ERR(ourport->baudclk))
1377 			clk_disable_unprepare(ourport->baudclk);
1378 
1379 		clk_disable_unprepare(ourport->clk);
1380 		break;
1381 
1382 	case 0:
1383 		clk_prepare_enable(ourport->clk);
1384 
1385 		if (!IS_ERR(ourport->baudclk))
1386 			clk_prepare_enable(ourport->baudclk);
1387 		break;
1388 	default:
1389 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1390 	}
1391 }
1392 
1393 /* baud rate calculation
1394  *
1395  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1396  * of different sources, including the peripheral clock ("pclk") and an
1397  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1398  * with a programmable extra divisor.
1399  *
1400  * The following code goes through the clock sources, and calculates the
1401  * baud clocks (and the resultant actual baud rates) and then tries to
1402  * pick the closest one and select that.
1403  *
1404  */
1405 
1406 #define MAX_CLK_NAME_LENGTH 15
1407 
1408 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1409 {
1410 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1411 	unsigned int ucon;
1412 
1413 	if (info->num_clks == 1)
1414 		return 0;
1415 
1416 	ucon = rd_regl(port, S3C2410_UCON);
1417 	ucon &= info->clksel_mask;
1418 	return ucon >> info->clksel_shift;
1419 }
1420 
1421 static void s3c24xx_serial_setsource(struct uart_port *port,
1422 			unsigned int clk_sel)
1423 {
1424 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1425 	unsigned int ucon;
1426 
1427 	if (info->num_clks == 1)
1428 		return;
1429 
1430 	ucon = rd_regl(port, S3C2410_UCON);
1431 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1432 		return;
1433 
1434 	ucon &= ~info->clksel_mask;
1435 	ucon |= clk_sel << info->clksel_shift;
1436 	wr_regl(port, S3C2410_UCON, ucon);
1437 }
1438 
1439 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1440 			unsigned int req_baud, struct clk **best_clk,
1441 			unsigned int *clk_num)
1442 {
1443 	const struct s3c24xx_uart_info *info = ourport->info;
1444 	struct clk *clk;
1445 	unsigned long rate;
1446 	unsigned int cnt, baud, quot, best_quot = 0;
1447 	char clkname[MAX_CLK_NAME_LENGTH];
1448 	int calc_deviation, deviation = (1 << 30) - 1;
1449 
1450 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1451 		/* Keep selected clock if provided */
1452 		if (ourport->cfg->clk_sel &&
1453 			!(ourport->cfg->clk_sel & (1 << cnt)))
1454 			continue;
1455 
1456 		sprintf(clkname, "clk_uart_baud%d", cnt);
1457 		clk = clk_get(ourport->port.dev, clkname);
1458 		if (IS_ERR(clk))
1459 			continue;
1460 
1461 		rate = clk_get_rate(clk);
1462 		if (!rate)
1463 			continue;
1464 
1465 		if (ourport->info->has_divslot) {
1466 			unsigned long div = rate / req_baud;
1467 
1468 			/* The UDIVSLOT register on the newer UARTs allows us to
1469 			 * get a divisor adjustment of 1/16th on the baud clock.
1470 			 *
1471 			 * We don't keep the UDIVSLOT value (the 16ths we
1472 			 * calculated by not multiplying the baud by 16) as it
1473 			 * is easy enough to recalculate.
1474 			 */
1475 
1476 			quot = div / 16;
1477 			baud = rate / div;
1478 		} else {
1479 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1480 			baud = rate / (quot * 16);
1481 		}
1482 		quot--;
1483 
1484 		calc_deviation = req_baud - baud;
1485 		if (calc_deviation < 0)
1486 			calc_deviation = -calc_deviation;
1487 
1488 		if (calc_deviation < deviation) {
1489 			*best_clk = clk;
1490 			best_quot = quot;
1491 			*clk_num = cnt;
1492 			deviation = calc_deviation;
1493 		}
1494 	}
1495 
1496 	return best_quot;
1497 }
1498 
1499 /* udivslot_table[]
1500  *
1501  * This table takes the fractional value of the baud divisor and gives
1502  * the recommended setting for the UDIVSLOT register.
1503  */
1504 static const u16 udivslot_table[16] = {
1505 	[0] = 0x0000,
1506 	[1] = 0x0080,
1507 	[2] = 0x0808,
1508 	[3] = 0x0888,
1509 	[4] = 0x2222,
1510 	[5] = 0x4924,
1511 	[6] = 0x4A52,
1512 	[7] = 0x54AA,
1513 	[8] = 0x5555,
1514 	[9] = 0xD555,
1515 	[10] = 0xD5D5,
1516 	[11] = 0xDDD5,
1517 	[12] = 0xDDDD,
1518 	[13] = 0xDFDD,
1519 	[14] = 0xDFDF,
1520 	[15] = 0xFFDF,
1521 };
1522 
1523 static void s3c24xx_serial_set_termios(struct uart_port *port,
1524 				       struct ktermios *termios,
1525 				       const struct ktermios *old)
1526 {
1527 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1528 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1529 	struct clk *clk = ERR_PTR(-EINVAL);
1530 	unsigned long flags;
1531 	unsigned int baud, quot, clk_sel = 0;
1532 	unsigned int ulcon;
1533 	unsigned int umcon;
1534 	unsigned int udivslot = 0;
1535 
1536 	/*
1537 	 * We don't support modem control lines.
1538 	 */
1539 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1540 	termios->c_cflag |= CLOCAL;
1541 
1542 	/*
1543 	 * Ask the core to calculate the divisor for us.
1544 	 */
1545 
1546 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1547 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1548 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1549 		quot = port->custom_divisor;
1550 	if (IS_ERR(clk))
1551 		return;
1552 
1553 	/* check to see if we need  to change clock source */
1554 
1555 	if (ourport->baudclk != clk) {
1556 		clk_prepare_enable(clk);
1557 
1558 		s3c24xx_serial_setsource(port, clk_sel);
1559 
1560 		if (!IS_ERR(ourport->baudclk)) {
1561 			clk_disable_unprepare(ourport->baudclk);
1562 			ourport->baudclk = ERR_PTR(-EINVAL);
1563 		}
1564 
1565 		ourport->baudclk = clk;
1566 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1567 	}
1568 
1569 	if (ourport->info->has_divslot) {
1570 		unsigned int div = ourport->baudclk_rate / baud;
1571 
1572 		if (cfg->has_fracval) {
1573 			udivslot = (div & 15);
1574 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1575 		} else {
1576 			udivslot = udivslot_table[div & 15];
1577 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1578 				udivslot, div & 15);
1579 		}
1580 	}
1581 
1582 	switch (termios->c_cflag & CSIZE) {
1583 	case CS5:
1584 		dev_dbg(port->dev, "config: 5bits/char\n");
1585 		ulcon = S3C2410_LCON_CS5;
1586 		break;
1587 	case CS6:
1588 		dev_dbg(port->dev, "config: 6bits/char\n");
1589 		ulcon = S3C2410_LCON_CS6;
1590 		break;
1591 	case CS7:
1592 		dev_dbg(port->dev, "config: 7bits/char\n");
1593 		ulcon = S3C2410_LCON_CS7;
1594 		break;
1595 	case CS8:
1596 	default:
1597 		dev_dbg(port->dev, "config: 8bits/char\n");
1598 		ulcon = S3C2410_LCON_CS8;
1599 		break;
1600 	}
1601 
1602 	/* preserve original lcon IR settings */
1603 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1604 
1605 	if (termios->c_cflag & CSTOPB)
1606 		ulcon |= S3C2410_LCON_STOPB;
1607 
1608 	if (termios->c_cflag & PARENB) {
1609 		if (termios->c_cflag & PARODD)
1610 			ulcon |= S3C2410_LCON_PODD;
1611 		else
1612 			ulcon |= S3C2410_LCON_PEVEN;
1613 	} else {
1614 		ulcon |= S3C2410_LCON_PNONE;
1615 	}
1616 
1617 	spin_lock_irqsave(&port->lock, flags);
1618 
1619 	dev_dbg(port->dev,
1620 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1621 		ulcon, quot, udivslot);
1622 
1623 	wr_regl(port, S3C2410_ULCON, ulcon);
1624 	wr_regl(port, S3C2410_UBRDIV, quot);
1625 
1626 	port->status &= ~UPSTAT_AUTOCTS;
1627 
1628 	umcon = rd_regl(port, S3C2410_UMCON);
1629 	if (termios->c_cflag & CRTSCTS) {
1630 		umcon |= S3C2410_UMCOM_AFC;
1631 		/* Disable RTS when RX FIFO contains 63 bytes */
1632 		umcon &= ~S3C2412_UMCON_AFC_8;
1633 		port->status = UPSTAT_AUTOCTS;
1634 	} else {
1635 		umcon &= ~S3C2410_UMCOM_AFC;
1636 	}
1637 	wr_regl(port, S3C2410_UMCON, umcon);
1638 
1639 	if (ourport->info->has_divslot)
1640 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1641 
1642 	dev_dbg(port->dev,
1643 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1644 		rd_regl(port, S3C2410_ULCON),
1645 		rd_regl(port, S3C2410_UCON),
1646 		rd_regl(port, S3C2410_UFCON));
1647 
1648 	/*
1649 	 * Update the per-port timeout.
1650 	 */
1651 	uart_update_timeout(port, termios->c_cflag, baud);
1652 
1653 	/*
1654 	 * Which character status flags are we interested in?
1655 	 */
1656 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1657 	if (termios->c_iflag & INPCK)
1658 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1659 			S3C2410_UERSTAT_PARITY;
1660 	/*
1661 	 * Which character status flags should we ignore?
1662 	 */
1663 	port->ignore_status_mask = 0;
1664 	if (termios->c_iflag & IGNPAR)
1665 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1666 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1667 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1668 
1669 	/*
1670 	 * Ignore all characters if CREAD is not set.
1671 	 */
1672 	if ((termios->c_cflag & CREAD) == 0)
1673 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1674 
1675 	spin_unlock_irqrestore(&port->lock, flags);
1676 }
1677 
1678 static const char *s3c24xx_serial_type(struct uart_port *port)
1679 {
1680 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
1681 
1682 	switch (ourport->info->type) {
1683 	case TYPE_S3C24XX:
1684 		return "S3C24XX";
1685 	case TYPE_S3C6400:
1686 		return "S3C6400/10";
1687 	case TYPE_APPLE_S5L:
1688 		return "APPLE S5L";
1689 	default:
1690 		return NULL;
1691 	}
1692 }
1693 
1694 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1695 {
1696 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1697 
1698 	if (flags & UART_CONFIG_TYPE)
1699 		port->type = info->port_type;
1700 }
1701 
1702 /*
1703  * verify the new serial_struct (for TIOCSSERIAL).
1704  */
1705 static int
1706 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1707 {
1708 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1709 
1710 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1711 		return -EINVAL;
1712 
1713 	return 0;
1714 }
1715 
1716 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1717 
1718 static struct console s3c24xx_serial_console;
1719 
1720 static void __init s3c24xx_serial_register_console(void)
1721 {
1722 	register_console(&s3c24xx_serial_console);
1723 }
1724 
1725 static void s3c24xx_serial_unregister_console(void)
1726 {
1727 	if (console_is_registered(&s3c24xx_serial_console))
1728 		unregister_console(&s3c24xx_serial_console);
1729 }
1730 
1731 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1732 #else
1733 static inline void s3c24xx_serial_register_console(void) { }
1734 static inline void s3c24xx_serial_unregister_console(void) { }
1735 #define S3C24XX_SERIAL_CONSOLE NULL
1736 #endif
1737 
1738 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1739 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1740 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1741 			 unsigned char c);
1742 #endif
1743 
1744 static const struct uart_ops s3c24xx_serial_ops = {
1745 	.pm		= s3c24xx_serial_pm,
1746 	.tx_empty	= s3c24xx_serial_tx_empty,
1747 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1748 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1749 	.stop_tx	= s3c24xx_serial_stop_tx,
1750 	.start_tx	= s3c24xx_serial_start_tx,
1751 	.stop_rx	= s3c24xx_serial_stop_rx,
1752 	.break_ctl	= s3c24xx_serial_break_ctl,
1753 	.startup	= s3c24xx_serial_startup,
1754 	.shutdown	= s3c24xx_serial_shutdown,
1755 	.set_termios	= s3c24xx_serial_set_termios,
1756 	.type		= s3c24xx_serial_type,
1757 	.config_port	= s3c24xx_serial_config_port,
1758 	.verify_port	= s3c24xx_serial_verify_port,
1759 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1760 	.poll_get_char = s3c24xx_serial_get_poll_char,
1761 	.poll_put_char = s3c24xx_serial_put_poll_char,
1762 #endif
1763 };
1764 
1765 static const struct uart_ops s3c64xx_serial_ops = {
1766 	.pm		= s3c24xx_serial_pm,
1767 	.tx_empty	= s3c24xx_serial_tx_empty,
1768 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1769 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1770 	.stop_tx	= s3c24xx_serial_stop_tx,
1771 	.start_tx	= s3c24xx_serial_start_tx,
1772 	.stop_rx	= s3c24xx_serial_stop_rx,
1773 	.break_ctl	= s3c24xx_serial_break_ctl,
1774 	.startup	= s3c64xx_serial_startup,
1775 	.shutdown	= s3c64xx_serial_shutdown,
1776 	.set_termios	= s3c24xx_serial_set_termios,
1777 	.type		= s3c24xx_serial_type,
1778 	.config_port	= s3c24xx_serial_config_port,
1779 	.verify_port	= s3c24xx_serial_verify_port,
1780 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1781 	.poll_get_char = s3c24xx_serial_get_poll_char,
1782 	.poll_put_char = s3c24xx_serial_put_poll_char,
1783 #endif
1784 };
1785 
1786 static const struct uart_ops apple_s5l_serial_ops = {
1787 	.pm		= s3c24xx_serial_pm,
1788 	.tx_empty	= s3c24xx_serial_tx_empty,
1789 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1790 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1791 	.stop_tx	= s3c24xx_serial_stop_tx,
1792 	.start_tx	= s3c24xx_serial_start_tx,
1793 	.stop_rx	= s3c24xx_serial_stop_rx,
1794 	.break_ctl	= s3c24xx_serial_break_ctl,
1795 	.startup	= apple_s5l_serial_startup,
1796 	.shutdown	= apple_s5l_serial_shutdown,
1797 	.set_termios	= s3c24xx_serial_set_termios,
1798 	.type		= s3c24xx_serial_type,
1799 	.config_port	= s3c24xx_serial_config_port,
1800 	.verify_port	= s3c24xx_serial_verify_port,
1801 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1802 	.poll_get_char = s3c24xx_serial_get_poll_char,
1803 	.poll_put_char = s3c24xx_serial_put_poll_char,
1804 #endif
1805 };
1806 
1807 static struct uart_driver s3c24xx_uart_drv = {
1808 	.owner		= THIS_MODULE,
1809 	.driver_name	= "s3c2410_serial",
1810 	.nr		= UART_NR,
1811 	.cons		= S3C24XX_SERIAL_CONSOLE,
1812 	.dev_name	= S3C24XX_SERIAL_NAME,
1813 	.major		= S3C24XX_SERIAL_MAJOR,
1814 	.minor		= S3C24XX_SERIAL_MINOR,
1815 };
1816 
1817 static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
1818 
1819 static void s3c24xx_serial_init_port_default(int index) {
1820 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1821 
1822 	spin_lock_init(&port->lock);
1823 
1824 	port->iotype = UPIO_MEM;
1825 	port->uartclk = 0;
1826 	port->fifosize = 16;
1827 	port->ops = &s3c24xx_serial_ops;
1828 	port->flags = UPF_BOOT_AUTOCONF;
1829 	port->line = index;
1830 }
1831 
1832 /* s3c24xx_serial_resetport
1833  *
1834  * reset the fifos and other the settings.
1835  */
1836 
1837 static void s3c24xx_serial_resetport(struct uart_port *port,
1838 				     const struct s3c2410_uartcfg *cfg)
1839 {
1840 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1841 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1842 
1843 	ucon &= (info->clksel_mask | info->ucon_mask);
1844 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1845 
1846 	/* reset both fifos */
1847 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1848 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1849 
1850 	/* some delay is required after fifo reset */
1851 	udelay(1);
1852 }
1853 
1854 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1855 {
1856 	struct device *dev = ourport->port.dev;
1857 	const struct s3c24xx_uart_info *info = ourport->info;
1858 	char clk_name[MAX_CLK_NAME_LENGTH];
1859 	unsigned int clk_sel;
1860 	struct clk *clk;
1861 	int clk_num;
1862 	int ret;
1863 
1864 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1865 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1866 		if (!(clk_sel & (1 << clk_num)))
1867 			continue;
1868 
1869 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1870 		clk = clk_get(dev, clk_name);
1871 		if (IS_ERR(clk))
1872 			continue;
1873 
1874 		ret = clk_prepare_enable(clk);
1875 		if (ret) {
1876 			clk_put(clk);
1877 			continue;
1878 		}
1879 
1880 		ourport->baudclk = clk;
1881 		ourport->baudclk_rate = clk_get_rate(clk);
1882 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1883 
1884 		return 0;
1885 	}
1886 
1887 	return -EINVAL;
1888 }
1889 
1890 /* s3c24xx_serial_init_port
1891  *
1892  * initialise a single serial port from the platform device given
1893  */
1894 
1895 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1896 				    struct platform_device *platdev)
1897 {
1898 	struct uart_port *port = &ourport->port;
1899 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1900 	struct resource *res;
1901 	int ret;
1902 
1903 	if (platdev == NULL)
1904 		return -ENODEV;
1905 
1906 	if (port->mapbase != 0)
1907 		return -EINVAL;
1908 
1909 	/* setup info for port */
1910 	port->dev	= &platdev->dev;
1911 
1912 	port->uartclk = 1;
1913 
1914 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1915 		dev_dbg(port->dev, "enabling flow control\n");
1916 		port->flags |= UPF_CONS_FLOW;
1917 	}
1918 
1919 	/* sort our the physical and virtual addresses for each UART */
1920 
1921 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1922 	if (res == NULL) {
1923 		dev_err(port->dev, "failed to find memory resource for uart\n");
1924 		return -EINVAL;
1925 	}
1926 
1927 	dev_dbg(port->dev, "resource %pR)\n", res);
1928 
1929 	port->membase = devm_ioremap_resource(port->dev, res);
1930 	if (IS_ERR(port->membase)) {
1931 		dev_err(port->dev, "failed to remap controller address\n");
1932 		return -EBUSY;
1933 	}
1934 
1935 	port->mapbase = res->start;
1936 	ret = platform_get_irq(platdev, 0);
1937 	if (ret < 0) {
1938 		port->irq = 0;
1939 	} else {
1940 		port->irq = ret;
1941 		ourport->rx_irq = ret;
1942 		ourport->tx_irq = ret + 1;
1943 	}
1944 
1945 	switch (ourport->info->type) {
1946 	case TYPE_S3C24XX:
1947 		ret = platform_get_irq(platdev, 1);
1948 		if (ret > 0)
1949 			ourport->tx_irq = ret;
1950 		break;
1951 	default:
1952 		break;
1953 	}
1954 
1955 	/*
1956 	 * DMA is currently supported only on DT platforms, if DMA properties
1957 	 * are specified.
1958 	 */
1959 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1960 						     "dmas", NULL)) {
1961 		ourport->dma = devm_kzalloc(port->dev,
1962 					    sizeof(*ourport->dma),
1963 					    GFP_KERNEL);
1964 		if (!ourport->dma) {
1965 			ret = -ENOMEM;
1966 			goto err;
1967 		}
1968 	}
1969 
1970 	ourport->clk	= clk_get(&platdev->dev, "uart");
1971 	if (IS_ERR(ourport->clk)) {
1972 		pr_err("%s: Controller clock not found\n",
1973 				dev_name(&platdev->dev));
1974 		ret = PTR_ERR(ourport->clk);
1975 		goto err;
1976 	}
1977 
1978 	ret = clk_prepare_enable(ourport->clk);
1979 	if (ret) {
1980 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1981 		clk_put(ourport->clk);
1982 		goto err;
1983 	}
1984 
1985 	ret = s3c24xx_serial_enable_baudclk(ourport);
1986 	if (ret)
1987 		pr_warn("uart: failed to enable baudclk\n");
1988 
1989 	/* Keep all interrupts masked and cleared */
1990 	switch (ourport->info->type) {
1991 	case TYPE_S3C6400:
1992 		wr_regl(port, S3C64XX_UINTM, 0xf);
1993 		wr_regl(port, S3C64XX_UINTP, 0xf);
1994 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1995 		break;
1996 	case TYPE_APPLE_S5L: {
1997 		unsigned int ucon;
1998 
1999 		ucon = rd_regl(port, S3C2410_UCON);
2000 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2001 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2002 			APPLE_S5L_UCON_RXTO_ENA_MSK);
2003 		wr_regl(port, S3C2410_UCON, ucon);
2004 
2005 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
2006 		break;
2007 	}
2008 	default:
2009 		break;
2010 	}
2011 
2012 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
2013 		&port->mapbase, port->membase, port->irq,
2014 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
2015 
2016 	/* reset the fifos (and setup the uart) */
2017 	s3c24xx_serial_resetport(port, cfg);
2018 
2019 	return 0;
2020 
2021 err:
2022 	port->mapbase = 0;
2023 	return ret;
2024 }
2025 
2026 /* Device driver serial port probe */
2027 
2028 static int probe_index;
2029 
2030 static inline const struct s3c24xx_serial_drv_data *
2031 s3c24xx_get_driver_data(struct platform_device *pdev)
2032 {
2033 	if (dev_of_node(&pdev->dev))
2034 		return of_device_get_match_data(&pdev->dev);
2035 
2036 	return (struct s3c24xx_serial_drv_data *)
2037 			platform_get_device_id(pdev)->driver_data;
2038 }
2039 
2040 static int s3c24xx_serial_probe(struct platform_device *pdev)
2041 {
2042 	struct device_node *np = pdev->dev.of_node;
2043 	struct s3c24xx_uart_port *ourport;
2044 	int index = probe_index;
2045 	int ret, prop = 0;
2046 
2047 	if (np) {
2048 		ret = of_alias_get_id(np, "serial");
2049 		if (ret >= 0)
2050 			index = ret;
2051 	}
2052 
2053 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2054 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2055 		return -EINVAL;
2056 	}
2057 	ourport = &s3c24xx_serial_ports[index];
2058 
2059 	s3c24xx_serial_init_port_default(index);
2060 
2061 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2062 	if (!ourport->drv_data) {
2063 		dev_err(&pdev->dev, "could not find driver data\n");
2064 		return -ENODEV;
2065 	}
2066 
2067 	ourport->baudclk = ERR_PTR(-EINVAL);
2068 	ourport->info = &ourport->drv_data->info;
2069 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2070 			dev_get_platdata(&pdev->dev) :
2071 			&ourport->drv_data->def_cfg;
2072 
2073 	switch (ourport->info->type) {
2074 	case TYPE_S3C24XX:
2075 		ourport->port.ops = &s3c24xx_serial_ops;
2076 		break;
2077 	case TYPE_S3C6400:
2078 		ourport->port.ops = &s3c64xx_serial_ops;
2079 		break;
2080 	case TYPE_APPLE_S5L:
2081 		ourport->port.ops = &apple_s5l_serial_ops;
2082 		break;
2083 	}
2084 
2085 	if (np) {
2086 		of_property_read_u32(np,
2087 			"samsung,uart-fifosize", &ourport->port.fifosize);
2088 
2089 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2090 			switch (prop) {
2091 			case 1:
2092 				ourport->port.iotype = UPIO_MEM;
2093 				break;
2094 			case 4:
2095 				ourport->port.iotype = UPIO_MEM32;
2096 				break;
2097 			default:
2098 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2099 						prop);
2100 				return -EINVAL;
2101 			}
2102 		}
2103 	}
2104 
2105 	if (ourport->drv_data->fifosize[index])
2106 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2107 	else if (ourport->info->fifosize)
2108 		ourport->port.fifosize = ourport->info->fifosize;
2109 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2110 
2111 	/*
2112 	 * DMA transfers must be aligned at least to cache line size,
2113 	 * so find minimal transfer size suitable for DMA mode
2114 	 */
2115 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2116 				    dma_get_cache_alignment());
2117 
2118 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2119 
2120 	ret = s3c24xx_serial_init_port(ourport, pdev);
2121 	if (ret < 0)
2122 		return ret;
2123 
2124 	if (!s3c24xx_uart_drv.state) {
2125 		ret = uart_register_driver(&s3c24xx_uart_drv);
2126 		if (ret < 0) {
2127 			pr_err("Failed to register Samsung UART driver\n");
2128 			return ret;
2129 		}
2130 	}
2131 
2132 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2133 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2134 	platform_set_drvdata(pdev, &ourport->port);
2135 
2136 	/*
2137 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2138 	 * so that a potential re-enablement through the pm-callback overlaps
2139 	 * and keeps the clock enabled in this case.
2140 	 */
2141 	clk_disable_unprepare(ourport->clk);
2142 	if (!IS_ERR(ourport->baudclk))
2143 		clk_disable_unprepare(ourport->baudclk);
2144 
2145 	probe_index++;
2146 
2147 	return 0;
2148 }
2149 
2150 static int s3c24xx_serial_remove(struct platform_device *dev)
2151 {
2152 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2153 
2154 	if (port) {
2155 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2156 	}
2157 
2158 	uart_unregister_driver(&s3c24xx_uart_drv);
2159 
2160 	return 0;
2161 }
2162 
2163 /* UART power management code */
2164 #ifdef CONFIG_PM_SLEEP
2165 static int s3c24xx_serial_suspend(struct device *dev)
2166 {
2167 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2168 
2169 	if (port)
2170 		uart_suspend_port(&s3c24xx_uart_drv, port);
2171 
2172 	return 0;
2173 }
2174 
2175 static int s3c24xx_serial_resume(struct device *dev)
2176 {
2177 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2178 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2179 
2180 	if (port) {
2181 		clk_prepare_enable(ourport->clk);
2182 		if (!IS_ERR(ourport->baudclk))
2183 			clk_prepare_enable(ourport->baudclk);
2184 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2185 		if (!IS_ERR(ourport->baudclk))
2186 			clk_disable_unprepare(ourport->baudclk);
2187 		clk_disable_unprepare(ourport->clk);
2188 
2189 		uart_resume_port(&s3c24xx_uart_drv, port);
2190 	}
2191 
2192 	return 0;
2193 }
2194 
2195 static int s3c24xx_serial_resume_noirq(struct device *dev)
2196 {
2197 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2198 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2199 
2200 	if (port) {
2201 		/* restore IRQ mask */
2202 		switch (ourport->info->type) {
2203 		case TYPE_S3C6400: {
2204 			unsigned int uintm = 0xf;
2205 
2206 			if (ourport->tx_enabled)
2207 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2208 			if (ourport->rx_enabled)
2209 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2210 			clk_prepare_enable(ourport->clk);
2211 			if (!IS_ERR(ourport->baudclk))
2212 				clk_prepare_enable(ourport->baudclk);
2213 			wr_regl(port, S3C64XX_UINTM, uintm);
2214 			if (!IS_ERR(ourport->baudclk))
2215 				clk_disable_unprepare(ourport->baudclk);
2216 			clk_disable_unprepare(ourport->clk);
2217 			break;
2218 		}
2219 		case TYPE_APPLE_S5L: {
2220 			unsigned int ucon;
2221 			int ret;
2222 
2223 			ret = clk_prepare_enable(ourport->clk);
2224 			if (ret) {
2225 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2226 				return ret;
2227 			}
2228 			if (!IS_ERR(ourport->baudclk)) {
2229 				ret = clk_prepare_enable(ourport->baudclk);
2230 				if (ret) {
2231 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2232 					clk_disable_unprepare(ourport->clk);
2233 					return ret;
2234 				}
2235 			}
2236 
2237 			ucon = rd_regl(port, S3C2410_UCON);
2238 
2239 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2240 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2241 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2242 
2243 			if (ourport->tx_enabled)
2244 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2245 			if (ourport->rx_enabled)
2246 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2247 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2248 
2249 			wr_regl(port, S3C2410_UCON, ucon);
2250 
2251 			if (!IS_ERR(ourport->baudclk))
2252 				clk_disable_unprepare(ourport->baudclk);
2253 			clk_disable_unprepare(ourport->clk);
2254 			break;
2255 		}
2256 		default:
2257 			break;
2258 		}
2259 	}
2260 
2261 	return 0;
2262 }
2263 
2264 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2265 	.suspend = s3c24xx_serial_suspend,
2266 	.resume = s3c24xx_serial_resume,
2267 	.resume_noirq = s3c24xx_serial_resume_noirq,
2268 };
2269 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2270 
2271 #else /* !CONFIG_PM_SLEEP */
2272 
2273 #define SERIAL_SAMSUNG_PM_OPS	NULL
2274 #endif /* CONFIG_PM_SLEEP */
2275 
2276 /* Console code */
2277 
2278 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2279 
2280 static struct uart_port *cons_uart;
2281 
2282 static int
2283 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2284 {
2285 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2286 	unsigned long ufstat, utrstat;
2287 
2288 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2289 		/* fifo mode - check amount of data in fifo registers... */
2290 
2291 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2292 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2293 	}
2294 
2295 	/* in non-fifo mode, we go and use the tx buffer empty */
2296 
2297 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2298 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2299 }
2300 
2301 static bool
2302 s3c24xx_port_configured(unsigned int ucon)
2303 {
2304 	/* consider the serial port configured if the tx/rx mode set */
2305 	return (ucon & 0xf) != 0;
2306 }
2307 
2308 #ifdef CONFIG_CONSOLE_POLL
2309 /*
2310  * Console polling routines for writing and reading from the uart while
2311  * in an interrupt or debug context.
2312  */
2313 
2314 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2315 {
2316 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2317 	unsigned int ufstat;
2318 
2319 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2320 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2321 		return NO_POLL_CHAR;
2322 
2323 	return rd_reg(port, S3C2410_URXH);
2324 }
2325 
2326 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2327 		unsigned char c)
2328 {
2329 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2330 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2331 
2332 	/* not possible to xmit on unconfigured port */
2333 	if (!s3c24xx_port_configured(ucon))
2334 		return;
2335 
2336 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2337 		cpu_relax();
2338 	wr_reg(port, S3C2410_UTXH, c);
2339 }
2340 
2341 #endif /* CONFIG_CONSOLE_POLL */
2342 
2343 static void
2344 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2345 {
2346 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2347 
2348 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2349 		cpu_relax();
2350 	wr_reg(port, S3C2410_UTXH, ch);
2351 }
2352 
2353 static void
2354 s3c24xx_serial_console_write(struct console *co, const char *s,
2355 			     unsigned int count)
2356 {
2357 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2358 	unsigned long flags;
2359 	bool locked = true;
2360 
2361 	/* not possible to xmit on unconfigured port */
2362 	if (!s3c24xx_port_configured(ucon))
2363 		return;
2364 
2365 	if (cons_uart->sysrq)
2366 		locked = false;
2367 	else if (oops_in_progress)
2368 		locked = spin_trylock_irqsave(&cons_uart->lock, flags);
2369 	else
2370 		spin_lock_irqsave(&cons_uart->lock, flags);
2371 
2372 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2373 
2374 	if (locked)
2375 		spin_unlock_irqrestore(&cons_uart->lock, flags);
2376 }
2377 
2378 /* Shouldn't be __init, as it can be instantiated from other module */
2379 static void
2380 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2381 			   int *parity, int *bits)
2382 {
2383 	struct clk *clk;
2384 	unsigned int ulcon;
2385 	unsigned int ucon;
2386 	unsigned int ubrdiv;
2387 	unsigned long rate;
2388 	unsigned int clk_sel;
2389 	char clk_name[MAX_CLK_NAME_LENGTH];
2390 
2391 	ulcon  = rd_regl(port, S3C2410_ULCON);
2392 	ucon   = rd_regl(port, S3C2410_UCON);
2393 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2394 
2395 	if (s3c24xx_port_configured(ucon)) {
2396 		switch (ulcon & S3C2410_LCON_CSMASK) {
2397 		case S3C2410_LCON_CS5:
2398 			*bits = 5;
2399 			break;
2400 		case S3C2410_LCON_CS6:
2401 			*bits = 6;
2402 			break;
2403 		case S3C2410_LCON_CS7:
2404 			*bits = 7;
2405 			break;
2406 		case S3C2410_LCON_CS8:
2407 		default:
2408 			*bits = 8;
2409 			break;
2410 		}
2411 
2412 		switch (ulcon & S3C2410_LCON_PMASK) {
2413 		case S3C2410_LCON_PEVEN:
2414 			*parity = 'e';
2415 			break;
2416 
2417 		case S3C2410_LCON_PODD:
2418 			*parity = 'o';
2419 			break;
2420 
2421 		case S3C2410_LCON_PNONE:
2422 		default:
2423 			*parity = 'n';
2424 		}
2425 
2426 		/* now calculate the baud rate */
2427 
2428 		clk_sel = s3c24xx_serial_getsource(port);
2429 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2430 
2431 		clk = clk_get(port->dev, clk_name);
2432 		if (!IS_ERR(clk))
2433 			rate = clk_get_rate(clk);
2434 		else
2435 			rate = 1;
2436 
2437 		*baud = rate / (16 * (ubrdiv + 1));
2438 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2439 	}
2440 }
2441 
2442 /* Shouldn't be __init, as it can be instantiated from other module */
2443 static int
2444 s3c24xx_serial_console_setup(struct console *co, char *options)
2445 {
2446 	struct uart_port *port;
2447 	int baud = 9600;
2448 	int bits = 8;
2449 	int parity = 'n';
2450 	int flow = 'n';
2451 
2452 	/* is this a valid port */
2453 
2454 	if (co->index == -1 || co->index >= UART_NR)
2455 		co->index = 0;
2456 
2457 	port = &s3c24xx_serial_ports[co->index].port;
2458 
2459 	/* is the port configured? */
2460 
2461 	if (port->mapbase == 0x0)
2462 		return -ENODEV;
2463 
2464 	cons_uart = port;
2465 
2466 	/*
2467 	 * Check whether an invalid uart number has been specified, and
2468 	 * if so, search for the first available port that does have
2469 	 * console support.
2470 	 */
2471 	if (options)
2472 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2473 	else
2474 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2475 
2476 	dev_dbg(port->dev, "baud %d\n", baud);
2477 
2478 	return uart_set_options(port, co, baud, parity, bits, flow);
2479 }
2480 
2481 static struct console s3c24xx_serial_console = {
2482 	.name		= S3C24XX_SERIAL_NAME,
2483 	.device		= uart_console_device,
2484 	.flags		= CON_PRINTBUFFER,
2485 	.index		= -1,
2486 	.write		= s3c24xx_serial_console_write,
2487 	.setup		= s3c24xx_serial_console_setup,
2488 	.data		= &s3c24xx_uart_drv,
2489 };
2490 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2491 
2492 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2493 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2494 	.info = {
2495 		.name		= "Samsung S3C6400 UART",
2496 		.type		= TYPE_S3C6400,
2497 		.port_type	= PORT_S3C6400,
2498 		.fifosize	= 64,
2499 		.has_divslot	= 1,
2500 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2501 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2502 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2503 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2504 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2505 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2506 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2507 		.num_clks	= 4,
2508 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2509 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2510 	},
2511 	.def_cfg = {
2512 		.ucon		= S3C2410_UCON_DEFAULT,
2513 		.ufcon		= S3C2410_UFCON_DEFAULT,
2514 	},
2515 };
2516 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2517 #else
2518 #define S3C6400_SERIAL_DRV_DATA NULL
2519 #endif
2520 
2521 #ifdef CONFIG_CPU_S5PV210
2522 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2523 	.info = {
2524 		.name		= "Samsung S5PV210 UART",
2525 		.type		= TYPE_S3C6400,
2526 		.port_type	= PORT_S3C6400,
2527 		.has_divslot	= 1,
2528 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2529 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2530 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2531 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2532 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2533 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2534 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2535 		.num_clks	= 2,
2536 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2537 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2538 	},
2539 	.def_cfg = {
2540 		.ucon		= S5PV210_UCON_DEFAULT,
2541 		.ufcon		= S5PV210_UFCON_DEFAULT,
2542 	},
2543 	.fifosize = { 256, 64, 16, 16 },
2544 };
2545 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2546 #else
2547 #define S5PV210_SERIAL_DRV_DATA	NULL
2548 #endif
2549 
2550 #if defined(CONFIG_ARCH_EXYNOS)
2551 #define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
2552 	.info = {						\
2553 		.name		= "Samsung Exynos UART",	\
2554 		.type		= TYPE_S3C6400,			\
2555 		.port_type	= PORT_S3C6400,			\
2556 		.has_divslot	= 1,				\
2557 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2558 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2559 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2560 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2561 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2562 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2563 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2564 		.num_clks	= 1,				\
2565 		.clksel_mask	= 0,				\
2566 		.clksel_shift	= 0,				\
2567 	},							\
2568 	.def_cfg = {						\
2569 		.ucon		= S5PV210_UCON_DEFAULT,		\
2570 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2571 		.has_fracval	= 1,				\
2572 	}							\
2573 
2574 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2575 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2576 	.fifosize = { 256, 64, 16, 16 },
2577 };
2578 
2579 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2580 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2581 	.fifosize = { 64, 256, 16, 256 },
2582 };
2583 
2584 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2585 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2586 	.fifosize = { 256, 64, 64, 64 },
2587 };
2588 
2589 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2590 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2591 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2592 
2593 #else
2594 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2595 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2596 #define EXYNOS850_SERIAL_DRV_DATA NULL
2597 #endif
2598 
2599 #ifdef CONFIG_ARCH_APPLE
2600 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2601 	.info = {
2602 		.name		= "Apple S5L UART",
2603 		.type		= TYPE_APPLE_S5L,
2604 		.port_type	= PORT_8250,
2605 		.fifosize	= 16,
2606 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2607 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2608 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2609 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2610 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2611 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2612 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2613 		.num_clks	= 1,
2614 		.clksel_mask	= 0,
2615 		.clksel_shift	= 0,
2616 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2617 	},
2618 	.def_cfg = {
2619 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2620 		.ufcon		= S3C2410_UFCON_DEFAULT,
2621 	},
2622 };
2623 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2624 #else
2625 #define S5L_SERIAL_DRV_DATA NULL
2626 #endif
2627 
2628 #if defined(CONFIG_ARCH_ARTPEC)
2629 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2630 	.info = {
2631 		.name		= "Axis ARTPEC-8 UART",
2632 		.type		= TYPE_S3C6400,
2633 		.port_type	= PORT_S3C6400,
2634 		.fifosize	= 64,
2635 		.has_divslot	= 1,
2636 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2637 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2638 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2639 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2640 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2641 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2642 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2643 		.num_clks	= 1,
2644 		.clksel_mask	= 0,
2645 		.clksel_shift	= 0,
2646 	},
2647 	.def_cfg = {
2648 		.ucon		= S5PV210_UCON_DEFAULT,
2649 		.ufcon		= S5PV210_UFCON_DEFAULT,
2650 		.has_fracval	= 1,
2651 	}
2652 };
2653 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2654 #else
2655 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2656 #endif
2657 
2658 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2659 	{
2660 		.name		= "s3c6400-uart",
2661 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2662 	}, {
2663 		.name		= "s5pv210-uart",
2664 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2665 	}, {
2666 		.name		= "exynos4210-uart",
2667 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2668 	}, {
2669 		.name		= "exynos5433-uart",
2670 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2671 	}, {
2672 		.name		= "s5l-uart",
2673 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2674 	}, {
2675 		.name		= "exynos850-uart",
2676 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2677 	}, {
2678 		.name		= "artpec8-uart",
2679 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2680 	},
2681 	{ },
2682 };
2683 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2684 
2685 #ifdef CONFIG_OF
2686 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2687 	{ .compatible = "samsung,s3c6400-uart",
2688 		.data = S3C6400_SERIAL_DRV_DATA },
2689 	{ .compatible = "samsung,s5pv210-uart",
2690 		.data = S5PV210_SERIAL_DRV_DATA },
2691 	{ .compatible = "samsung,exynos4210-uart",
2692 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2693 	{ .compatible = "samsung,exynos5433-uart",
2694 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2695 	{ .compatible = "apple,s5l-uart",
2696 		.data = S5L_SERIAL_DRV_DATA },
2697 	{ .compatible = "samsung,exynos850-uart",
2698 		.data = EXYNOS850_SERIAL_DRV_DATA },
2699 	{ .compatible = "axis,artpec8-uart",
2700 		.data = ARTPEC8_SERIAL_DRV_DATA },
2701 	{},
2702 };
2703 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2704 #endif
2705 
2706 static struct platform_driver samsung_serial_driver = {
2707 	.probe		= s3c24xx_serial_probe,
2708 	.remove		= s3c24xx_serial_remove,
2709 	.id_table	= s3c24xx_serial_driver_ids,
2710 	.driver		= {
2711 		.name	= "samsung-uart",
2712 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2713 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2714 	},
2715 };
2716 
2717 static int __init samsung_serial_init(void)
2718 {
2719 	int ret;
2720 
2721 	s3c24xx_serial_register_console();
2722 
2723 	ret = platform_driver_register(&samsung_serial_driver);
2724 	if (ret) {
2725 		s3c24xx_serial_unregister_console();
2726 		return ret;
2727 	}
2728 
2729 	return 0;
2730 }
2731 
2732 static void __exit samsung_serial_exit(void)
2733 {
2734 	platform_driver_unregister(&samsung_serial_driver);
2735 	s3c24xx_serial_unregister_console();
2736 }
2737 
2738 module_init(samsung_serial_init);
2739 module_exit(samsung_serial_exit);
2740 
2741 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2742 /*
2743  * Early console.
2744  */
2745 
2746 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2747 {
2748 	switch (port->iotype) {
2749 	case UPIO_MEM:
2750 		writeb(val, portaddr(port, reg));
2751 		break;
2752 	case UPIO_MEM32:
2753 		writel(val, portaddr(port, reg));
2754 		break;
2755 	}
2756 }
2757 
2758 struct samsung_early_console_data {
2759 	u32 txfull_mask;
2760 	u32 rxfifo_mask;
2761 };
2762 
2763 static void samsung_early_busyuart(const struct uart_port *port)
2764 {
2765 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2766 		;
2767 }
2768 
2769 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2770 {
2771 	const struct samsung_early_console_data *data = port->private_data;
2772 
2773 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2774 		;
2775 }
2776 
2777 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2778 {
2779 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2780 		samsung_early_busyuart_fifo(port);
2781 	else
2782 		samsung_early_busyuart(port);
2783 
2784 	wr_reg_barrier(port, S3C2410_UTXH, c);
2785 }
2786 
2787 static void samsung_early_write(struct console *con, const char *s,
2788 				unsigned int n)
2789 {
2790 	struct earlycon_device *dev = con->data;
2791 
2792 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2793 }
2794 
2795 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2796 {
2797 	struct earlycon_device *dev = con->data;
2798 	const struct samsung_early_console_data *data = dev->port.private_data;
2799 	int ch, ufstat, num_read = 0;
2800 
2801 	while (num_read < n) {
2802 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
2803 		if (!(ufstat & data->rxfifo_mask))
2804 			break;
2805 		ch = rd_reg(&dev->port, S3C2410_URXH);
2806 		if (ch == NO_POLL_CHAR)
2807 			break;
2808 
2809 		s[num_read++] = ch;
2810 	}
2811 
2812 	return num_read;
2813 }
2814 
2815 static int __init samsung_early_console_setup(struct earlycon_device *device,
2816 					      const char *opt)
2817 {
2818 	if (!device->port.membase)
2819 		return -ENODEV;
2820 
2821 	device->con->write = samsung_early_write;
2822 	device->con->read = samsung_early_read;
2823 	return 0;
2824 }
2825 
2826 /* S3C2410 */
2827 static struct samsung_early_console_data s3c2410_early_console_data = {
2828 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2829 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
2830 };
2831 
2832 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
2833 					      const char *opt)
2834 {
2835 	device->port.private_data = &s3c2410_early_console_data;
2836 	return samsung_early_console_setup(device, opt);
2837 }
2838 
2839 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
2840 			s3c2410_early_console_setup);
2841 
2842 /* S3C2412, S3C2440, S3C64xx */
2843 static struct samsung_early_console_data s3c2440_early_console_data = {
2844 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2845 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
2846 };
2847 
2848 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2849 					      const char *opt)
2850 {
2851 	device->port.private_data = &s3c2440_early_console_data;
2852 	return samsung_early_console_setup(device, opt);
2853 }
2854 
2855 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
2856 			s3c2440_early_console_setup);
2857 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
2858 			s3c2440_early_console_setup);
2859 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2860 			s3c2440_early_console_setup);
2861 
2862 /* S5PV210, Exynos */
2863 static struct samsung_early_console_data s5pv210_early_console_data = {
2864 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2865 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
2866 };
2867 
2868 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2869 					      const char *opt)
2870 {
2871 	device->port.private_data = &s5pv210_early_console_data;
2872 	return samsung_early_console_setup(device, opt);
2873 }
2874 
2875 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2876 			s5pv210_early_console_setup);
2877 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2878 			s5pv210_early_console_setup);
2879 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
2880 			s5pv210_early_console_setup);
2881 
2882 /* Apple S5L */
2883 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
2884 						const char *opt)
2885 {
2886 	/* Close enough to S3C2410 for earlycon... */
2887 	device->port.private_data = &s3c2410_early_console_data;
2888 
2889 #ifdef CONFIG_ARM64
2890 	/* ... but we need to override the existing fixmap entry as nGnRnE */
2891 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
2892 		     __pgprot(PROT_DEVICE_nGnRnE));
2893 #endif
2894 	return samsung_early_console_setup(device, opt);
2895 }
2896 
2897 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
2898 #endif
2899 
2900 MODULE_ALIAS("platform:samsung-uart");
2901 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2902 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2903 MODULE_LICENSE("GPL v2");
2904