xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision 5388b581)
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 /* Hote 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 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
25 #define SUPPORT_SYSRQ
26 #endif
27 
28 #include <linux/dmaengine.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/slab.h>
31 #include <linux/module.h>
32 #include <linux/ioport.h>
33 #include <linux/io.h>
34 #include <linux/platform_device.h>
35 #include <linux/init.h>
36 #include <linux/sysrq.h>
37 #include <linux/console.h>
38 #include <linux/tty.h>
39 #include <linux/tty_flip.h>
40 #include <linux/serial_core.h>
41 #include <linux/serial.h>
42 #include <linux/serial_s3c.h>
43 #include <linux/delay.h>
44 #include <linux/clk.h>
45 #include <linux/cpufreq.h>
46 #include <linux/of.h>
47 
48 #include <asm/irq.h>
49 
50 #include "samsung.h"
51 
52 #if	defined(CONFIG_SERIAL_SAMSUNG_DEBUG) &&	\
53 	!defined(MODULE)
54 
55 extern void printascii(const char *);
56 
57 __printf(1, 2)
58 static void dbg(const char *fmt, ...)
59 {
60 	va_list va;
61 	char buff[256];
62 
63 	va_start(va, fmt);
64 	vscnprintf(buff, sizeof(buff), fmt, va);
65 	va_end(va);
66 
67 	printascii(buff);
68 }
69 
70 #else
71 #define dbg(fmt, ...) do { if (0) no_printk(fmt, ##__VA_ARGS__); } while (0)
72 #endif
73 
74 /* UART name and device definitions */
75 
76 #define S3C24XX_SERIAL_NAME	"ttySAC"
77 #define S3C24XX_SERIAL_MAJOR	204
78 #define S3C24XX_SERIAL_MINOR	64
79 
80 #define S3C24XX_TX_PIO			1
81 #define S3C24XX_TX_DMA			2
82 #define S3C24XX_RX_PIO			1
83 #define S3C24XX_RX_DMA			2
84 /* macros to change one thing to another */
85 
86 #define tx_enabled(port) ((port)->unused[0])
87 #define rx_enabled(port) ((port)->unused[1])
88 
89 /* flag to ignore all characters coming in */
90 #define RXSTAT_DUMMY_READ (0x10000000)
91 
92 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
93 {
94 	return container_of(port, struct s3c24xx_uart_port, port);
95 }
96 
97 /* translate a port to the device name */
98 
99 static inline const char *s3c24xx_serial_portname(struct uart_port *port)
100 {
101 	return to_platform_device(port->dev)->name;
102 }
103 
104 static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
105 {
106 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
107 }
108 
109 /*
110  * s3c64xx and later SoC's include the interrupt mask and status registers in
111  * the controller itself, unlike the s3c24xx SoC's which have these registers
112  * in the interrupt controller. Check if the port type is s3c64xx or higher.
113  */
114 static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
115 {
116 	return to_ourport(port)->info->type == PORT_S3C6400;
117 }
118 
119 static void s3c24xx_serial_rx_enable(struct uart_port *port)
120 {
121 	unsigned long flags;
122 	unsigned int ucon, ufcon;
123 	int count = 10000;
124 
125 	spin_lock_irqsave(&port->lock, flags);
126 
127 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
128 		udelay(100);
129 
130 	ufcon = rd_regl(port, S3C2410_UFCON);
131 	ufcon |= S3C2410_UFCON_RESETRX;
132 	wr_regl(port, S3C2410_UFCON, ufcon);
133 
134 	ucon = rd_regl(port, S3C2410_UCON);
135 	ucon |= S3C2410_UCON_RXIRQMODE;
136 	wr_regl(port, S3C2410_UCON, ucon);
137 
138 	rx_enabled(port) = 1;
139 	spin_unlock_irqrestore(&port->lock, flags);
140 }
141 
142 static void s3c24xx_serial_rx_disable(struct uart_port *port)
143 {
144 	unsigned long flags;
145 	unsigned int ucon;
146 
147 	spin_lock_irqsave(&port->lock, flags);
148 
149 	ucon = rd_regl(port, S3C2410_UCON);
150 	ucon &= ~S3C2410_UCON_RXIRQMODE;
151 	wr_regl(port, S3C2410_UCON, ucon);
152 
153 	rx_enabled(port) = 0;
154 	spin_unlock_irqrestore(&port->lock, flags);
155 }
156 
157 static void s3c24xx_serial_stop_tx(struct uart_port *port)
158 {
159 	struct s3c24xx_uart_port *ourport = to_ourport(port);
160 	struct s3c24xx_uart_dma *dma = ourport->dma;
161 	struct circ_buf *xmit = &port->state->xmit;
162 	struct dma_tx_state state;
163 	int count;
164 
165 	if (!tx_enabled(port))
166 		return;
167 
168 	if (s3c24xx_serial_has_interrupt_mask(port))
169 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
170 	else
171 		disable_irq_nosync(ourport->tx_irq);
172 
173 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
174 		dmaengine_pause(dma->tx_chan);
175 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
176 		dmaengine_terminate_all(dma->tx_chan);
177 		dma_sync_single_for_cpu(ourport->port.dev,
178 			dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE);
179 		async_tx_ack(dma->tx_desc);
180 		count = dma->tx_bytes_requested - state.residue;
181 		xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
182 		port->icount.tx += count;
183 	}
184 
185 	tx_enabled(port) = 0;
186 	ourport->tx_in_progress = 0;
187 
188 	if (port->flags & UPF_CONS_FLOW)
189 		s3c24xx_serial_rx_enable(port);
190 
191 	ourport->tx_mode = 0;
192 }
193 
194 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
195 
196 static void s3c24xx_serial_tx_dma_complete(void *args)
197 {
198 	struct s3c24xx_uart_port *ourport = args;
199 	struct uart_port *port = &ourport->port;
200 	struct circ_buf *xmit = &port->state->xmit;
201 	struct s3c24xx_uart_dma *dma = ourport->dma;
202 	struct dma_tx_state state;
203 	unsigned long flags;
204 	int count;
205 
206 
207 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
208 	count = dma->tx_bytes_requested - state.residue;
209 	async_tx_ack(dma->tx_desc);
210 
211 	dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr,
212 				dma->tx_size, DMA_TO_DEVICE);
213 
214 	spin_lock_irqsave(&port->lock, flags);
215 
216 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
217 	port->icount.tx += count;
218 	ourport->tx_in_progress = 0;
219 
220 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
221 		uart_write_wakeup(port);
222 
223 	s3c24xx_serial_start_next_tx(ourport);
224 	spin_unlock_irqrestore(&port->lock, flags);
225 }
226 
227 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
228 {
229 	struct uart_port *port = &ourport->port;
230 	u32 ucon;
231 
232 	/* Mask Tx interrupt */
233 	if (s3c24xx_serial_has_interrupt_mask(port))
234 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
235 	else
236 		disable_irq_nosync(ourport->tx_irq);
237 
238 	/* Enable tx dma mode */
239 	ucon = rd_regl(port, S3C2410_UCON);
240 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
241 	ucon |= (dma_get_cache_alignment() >= 16) ?
242 		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
243 	ucon |= S3C64XX_UCON_TXMODE_DMA;
244 	wr_regl(port,  S3C2410_UCON, ucon);
245 
246 	ourport->tx_mode = S3C24XX_TX_DMA;
247 }
248 
249 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
250 {
251 	struct uart_port *port = &ourport->port;
252 	u32 ucon, ufcon;
253 
254 	/* Set ufcon txtrig */
255 	ourport->tx_in_progress = S3C24XX_TX_PIO;
256 	ufcon = rd_regl(port, S3C2410_UFCON);
257 	wr_regl(port,  S3C2410_UFCON, ufcon);
258 
259 	/* Enable tx pio mode */
260 	ucon = rd_regl(port, S3C2410_UCON);
261 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
262 	ucon |= S3C64XX_UCON_TXMODE_CPU;
263 	wr_regl(port,  S3C2410_UCON, ucon);
264 
265 	/* Unmask Tx interrupt */
266 	if (s3c24xx_serial_has_interrupt_mask(port))
267 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
268 				  S3C64XX_UINTM);
269 	else
270 		enable_irq(ourport->tx_irq);
271 
272 	ourport->tx_mode = S3C24XX_TX_PIO;
273 }
274 
275 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
276 {
277 	if (ourport->tx_mode != S3C24XX_TX_PIO)
278 		enable_tx_pio(ourport);
279 }
280 
281 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
282 				      unsigned int count)
283 {
284 	struct uart_port *port = &ourport->port;
285 	struct circ_buf *xmit = &port->state->xmit;
286 	struct s3c24xx_uart_dma *dma = ourport->dma;
287 
288 
289 	if (ourport->tx_mode != S3C24XX_TX_DMA)
290 		enable_tx_dma(ourport);
291 
292 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
293 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
294 
295 	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
296 				dma->tx_size, DMA_TO_DEVICE);
297 
298 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
299 				dma->tx_transfer_addr, dma->tx_size,
300 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
301 	if (!dma->tx_desc) {
302 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
303 		return -EIO;
304 	}
305 
306 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
307 	dma->tx_desc->callback_param = ourport;
308 	dma->tx_bytes_requested = dma->tx_size;
309 
310 	ourport->tx_in_progress = S3C24XX_TX_DMA;
311 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
312 	dma_async_issue_pending(dma->tx_chan);
313 	return 0;
314 }
315 
316 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
317 {
318 	struct uart_port *port = &ourport->port;
319 	struct circ_buf *xmit = &port->state->xmit;
320 	unsigned long count;
321 
322 	/* Get data size up to the end of buffer */
323 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
324 
325 	if (!count) {
326 		s3c24xx_serial_stop_tx(port);
327 		return;
328 	}
329 
330 	if (!ourport->dma || !ourport->dma->tx_chan ||
331 	    count < ourport->min_dma_size ||
332 	    xmit->tail & (dma_get_cache_alignment() - 1))
333 		s3c24xx_serial_start_tx_pio(ourport);
334 	else
335 		s3c24xx_serial_start_tx_dma(ourport, count);
336 }
337 
338 static void s3c24xx_serial_start_tx(struct uart_port *port)
339 {
340 	struct s3c24xx_uart_port *ourport = to_ourport(port);
341 	struct circ_buf *xmit = &port->state->xmit;
342 
343 	if (!tx_enabled(port)) {
344 		if (port->flags & UPF_CONS_FLOW)
345 			s3c24xx_serial_rx_disable(port);
346 
347 		tx_enabled(port) = 1;
348 		if (!ourport->dma || !ourport->dma->tx_chan)
349 			s3c24xx_serial_start_tx_pio(ourport);
350 	}
351 
352 	if (ourport->dma && ourport->dma->tx_chan) {
353 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
354 			s3c24xx_serial_start_next_tx(ourport);
355 	}
356 }
357 
358 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
359 		struct tty_port *tty, int count)
360 {
361 	struct s3c24xx_uart_dma *dma = ourport->dma;
362 	int copied;
363 
364 	if (!count)
365 		return;
366 
367 	dma_sync_single_for_cpu(ourport->port.dev, dma->rx_addr,
368 				dma->rx_size, DMA_FROM_DEVICE);
369 
370 	ourport->port.icount.rx += count;
371 	if (!tty) {
372 		dev_err(ourport->port.dev, "No tty port\n");
373 		return;
374 	}
375 	copied = tty_insert_flip_string(tty,
376 			((unsigned char *)(ourport->dma->rx_buf)), count);
377 	if (copied != count) {
378 		WARN_ON(1);
379 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
380 	}
381 }
382 
383 static void s3c24xx_serial_stop_rx(struct uart_port *port)
384 {
385 	struct s3c24xx_uart_port *ourport = to_ourport(port);
386 	struct s3c24xx_uart_dma *dma = ourport->dma;
387 	struct tty_port *t = &port->state->port;
388 	struct dma_tx_state state;
389 	enum dma_status dma_status;
390 	unsigned int received;
391 
392 	if (rx_enabled(port)) {
393 		dbg("s3c24xx_serial_stop_rx: port=%p\n", port);
394 		if (s3c24xx_serial_has_interrupt_mask(port))
395 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
396 					S3C64XX_UINTM);
397 		else
398 			disable_irq_nosync(ourport->rx_irq);
399 		rx_enabled(port) = 0;
400 	}
401 	if (dma && dma->rx_chan) {
402 		dmaengine_pause(dma->tx_chan);
403 		dma_status = dmaengine_tx_status(dma->rx_chan,
404 				dma->rx_cookie, &state);
405 		if (dma_status == DMA_IN_PROGRESS ||
406 			dma_status == DMA_PAUSED) {
407 			received = dma->rx_bytes_requested - state.residue;
408 			dmaengine_terminate_all(dma->rx_chan);
409 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
410 		}
411 	}
412 }
413 
414 static inline struct s3c24xx_uart_info
415 	*s3c24xx_port_to_info(struct uart_port *port)
416 {
417 	return to_ourport(port)->info;
418 }
419 
420 static inline struct s3c2410_uartcfg
421 	*s3c24xx_port_to_cfg(struct uart_port *port)
422 {
423 	struct s3c24xx_uart_port *ourport;
424 
425 	if (port->dev == NULL)
426 		return NULL;
427 
428 	ourport = container_of(port, struct s3c24xx_uart_port, port);
429 	return ourport->cfg;
430 }
431 
432 static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
433 				     unsigned long ufstat)
434 {
435 	struct s3c24xx_uart_info *info = ourport->info;
436 
437 	if (ufstat & info->rx_fifofull)
438 		return ourport->port.fifosize;
439 
440 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
441 }
442 
443 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
444 static void s3c24xx_serial_rx_dma_complete(void *args)
445 {
446 	struct s3c24xx_uart_port *ourport = args;
447 	struct uart_port *port = &ourport->port;
448 
449 	struct s3c24xx_uart_dma *dma = ourport->dma;
450 	struct tty_port *t = &port->state->port;
451 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
452 
453 	struct dma_tx_state state;
454 	unsigned long flags;
455 	int received;
456 
457 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
458 	received  = dma->rx_bytes_requested - state.residue;
459 	async_tx_ack(dma->rx_desc);
460 
461 	spin_lock_irqsave(&port->lock, flags);
462 
463 	if (received)
464 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
465 
466 	if (tty) {
467 		tty_flip_buffer_push(t);
468 		tty_kref_put(tty);
469 	}
470 
471 	s3c64xx_start_rx_dma(ourport);
472 
473 	spin_unlock_irqrestore(&port->lock, flags);
474 }
475 
476 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
477 {
478 	struct s3c24xx_uart_dma *dma = ourport->dma;
479 
480 	dma_sync_single_for_device(ourport->port.dev, dma->rx_addr,
481 				dma->rx_size, DMA_FROM_DEVICE);
482 
483 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
484 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
485 				DMA_PREP_INTERRUPT);
486 	if (!dma->rx_desc) {
487 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
488 		return;
489 	}
490 
491 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
492 	dma->rx_desc->callback_param = ourport;
493 	dma->rx_bytes_requested = dma->rx_size;
494 
495 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
496 	dma_async_issue_pending(dma->rx_chan);
497 }
498 
499 /* ? - where has parity gone?? */
500 #define S3C2410_UERSTAT_PARITY (0x1000)
501 
502 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
503 {
504 	struct uart_port *port = &ourport->port;
505 	unsigned int ucon;
506 
507 	/* set Rx mode to DMA mode */
508 	ucon = rd_regl(port, S3C2410_UCON);
509 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
510 			S3C64XX_UCON_TIMEOUT_MASK |
511 			S3C64XX_UCON_EMPTYINT_EN |
512 			S3C64XX_UCON_DMASUS_EN |
513 			S3C64XX_UCON_TIMEOUT_EN |
514 			S3C64XX_UCON_RXMODE_MASK);
515 	ucon |= S3C64XX_UCON_RXBURST_16 |
516 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
517 			S3C64XX_UCON_EMPTYINT_EN |
518 			S3C64XX_UCON_TIMEOUT_EN |
519 			S3C64XX_UCON_RXMODE_DMA;
520 	wr_regl(port, S3C2410_UCON, ucon);
521 
522 	ourport->rx_mode = S3C24XX_RX_DMA;
523 }
524 
525 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
526 {
527 	struct uart_port *port = &ourport->port;
528 	unsigned int ucon;
529 
530 	/* set Rx mode to DMA mode */
531 	ucon = rd_regl(port, S3C2410_UCON);
532 	ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
533 			S3C64XX_UCON_EMPTYINT_EN |
534 			S3C64XX_UCON_DMASUS_EN |
535 			S3C64XX_UCON_TIMEOUT_EN |
536 			S3C64XX_UCON_RXMODE_MASK);
537 	ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
538 			S3C64XX_UCON_TIMEOUT_EN |
539 			S3C64XX_UCON_RXMODE_CPU;
540 	wr_regl(port, S3C2410_UCON, ucon);
541 
542 	ourport->rx_mode = S3C24XX_RX_PIO;
543 }
544 
545 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
546 
547 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
548 {
549 	unsigned int utrstat, ufstat, received;
550 	struct s3c24xx_uart_port *ourport = dev_id;
551 	struct uart_port *port = &ourport->port;
552 	struct s3c24xx_uart_dma *dma = ourport->dma;
553 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
554 	struct tty_port *t = &port->state->port;
555 	unsigned long flags;
556 	struct dma_tx_state state;
557 
558 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
559 	ufstat = rd_regl(port, S3C2410_UFSTAT);
560 
561 	spin_lock_irqsave(&port->lock, flags);
562 
563 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
564 		s3c64xx_start_rx_dma(ourport);
565 		if (ourport->rx_mode == S3C24XX_RX_PIO)
566 			enable_rx_dma(ourport);
567 		goto finish;
568 	}
569 
570 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
571 		dmaengine_pause(dma->rx_chan);
572 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
573 		dmaengine_terminate_all(dma->rx_chan);
574 		received = dma->rx_bytes_requested - state.residue;
575 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
576 
577 		enable_rx_pio(ourport);
578 	}
579 
580 	s3c24xx_serial_rx_drain_fifo(ourport);
581 
582 	if (tty) {
583 		tty_flip_buffer_push(t);
584 		tty_kref_put(tty);
585 	}
586 
587 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
588 
589 finish:
590 	spin_unlock_irqrestore(&port->lock, flags);
591 
592 	return IRQ_HANDLED;
593 }
594 
595 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
596 {
597 	struct uart_port *port = &ourport->port;
598 	unsigned int ufcon, ch, flag, ufstat, uerstat;
599 	unsigned int fifocnt = 0;
600 	int max_count = port->fifosize;
601 
602 	while (max_count-- > 0) {
603 		/*
604 		 * Receive all characters known to be in FIFO
605 		 * before reading FIFO level again
606 		 */
607 		if (fifocnt == 0) {
608 			ufstat = rd_regl(port, S3C2410_UFSTAT);
609 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
610 			if (fifocnt == 0)
611 				break;
612 		}
613 		fifocnt--;
614 
615 		uerstat = rd_regl(port, S3C2410_UERSTAT);
616 		ch = rd_regb(port, S3C2410_URXH);
617 
618 		if (port->flags & UPF_CONS_FLOW) {
619 			int txe = s3c24xx_serial_txempty_nofifo(port);
620 
621 			if (rx_enabled(port)) {
622 				if (!txe) {
623 					rx_enabled(port) = 0;
624 					continue;
625 				}
626 			} else {
627 				if (txe) {
628 					ufcon = rd_regl(port, S3C2410_UFCON);
629 					ufcon |= S3C2410_UFCON_RESETRX;
630 					wr_regl(port, S3C2410_UFCON, ufcon);
631 					rx_enabled(port) = 1;
632 					return;
633 				}
634 				continue;
635 			}
636 		}
637 
638 		/* insert the character into the buffer */
639 
640 		flag = TTY_NORMAL;
641 		port->icount.rx++;
642 
643 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
644 			dbg("rxerr: port ch=0x%02x, rxs=0x%08x\n",
645 			    ch, uerstat);
646 
647 			/* check for break */
648 			if (uerstat & S3C2410_UERSTAT_BREAK) {
649 				dbg("break!\n");
650 				port->icount.brk++;
651 				if (uart_handle_break(port))
652 					continue; /* Ignore character */
653 			}
654 
655 			if (uerstat & S3C2410_UERSTAT_FRAME)
656 				port->icount.frame++;
657 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
658 				port->icount.overrun++;
659 
660 			uerstat &= port->read_status_mask;
661 
662 			if (uerstat & S3C2410_UERSTAT_BREAK)
663 				flag = TTY_BREAK;
664 			else if (uerstat & S3C2410_UERSTAT_PARITY)
665 				flag = TTY_PARITY;
666 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
667 					    S3C2410_UERSTAT_OVERRUN))
668 				flag = TTY_FRAME;
669 		}
670 
671 		if (uart_handle_sysrq_char(port, ch))
672 			continue; /* Ignore character */
673 
674 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
675 				 ch, flag);
676 	}
677 
678 	tty_flip_buffer_push(&port->state->port);
679 }
680 
681 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
682 {
683 	struct s3c24xx_uart_port *ourport = dev_id;
684 	struct uart_port *port = &ourport->port;
685 	unsigned long flags;
686 
687 	spin_lock_irqsave(&port->lock, flags);
688 	s3c24xx_serial_rx_drain_fifo(ourport);
689 	spin_unlock_irqrestore(&port->lock, flags);
690 
691 	return IRQ_HANDLED;
692 }
693 
694 
695 static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id)
696 {
697 	struct s3c24xx_uart_port *ourport = dev_id;
698 
699 	if (ourport->dma && ourport->dma->rx_chan)
700 		return s3c24xx_serial_rx_chars_dma(dev_id);
701 	return s3c24xx_serial_rx_chars_pio(dev_id);
702 }
703 
704 static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
705 {
706 	struct s3c24xx_uart_port *ourport = id;
707 	struct uart_port *port = &ourport->port;
708 	struct circ_buf *xmit = &port->state->xmit;
709 	unsigned long flags;
710 	int count, dma_count = 0;
711 
712 	spin_lock_irqsave(&port->lock, flags);
713 
714 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
715 
716 	if (ourport->dma && ourport->dma->tx_chan &&
717 	    count >= ourport->min_dma_size) {
718 		int align = dma_get_cache_alignment() -
719 			(xmit->tail & (dma_get_cache_alignment() - 1));
720 		if (count-align >= ourport->min_dma_size) {
721 			dma_count = count-align;
722 			count = align;
723 		}
724 	}
725 
726 	if (port->x_char) {
727 		wr_regb(port, S3C2410_UTXH, port->x_char);
728 		port->icount.tx++;
729 		port->x_char = 0;
730 		goto out;
731 	}
732 
733 	/* if there isn't anything more to transmit, or the uart is now
734 	 * stopped, disable the uart and exit
735 	*/
736 
737 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
738 		s3c24xx_serial_stop_tx(port);
739 		goto out;
740 	}
741 
742 	/* try and drain the buffer... */
743 
744 	if (count > port->fifosize) {
745 		count = port->fifosize;
746 		dma_count = 0;
747 	}
748 
749 	while (!uart_circ_empty(xmit) && count > 0) {
750 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
751 			break;
752 
753 		wr_regb(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
754 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
755 		port->icount.tx++;
756 		count--;
757 	}
758 
759 	if (!count && dma_count) {
760 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
761 		goto out;
762 	}
763 
764 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
765 		spin_unlock(&port->lock);
766 		uart_write_wakeup(port);
767 		spin_lock(&port->lock);
768 	}
769 
770 	if (uart_circ_empty(xmit))
771 		s3c24xx_serial_stop_tx(port);
772 
773 out:
774 	spin_unlock_irqrestore(&port->lock, flags);
775 	return IRQ_HANDLED;
776 }
777 
778 /* interrupt handler for s3c64xx and later SoC's.*/
779 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
780 {
781 	struct s3c24xx_uart_port *ourport = id;
782 	struct uart_port *port = &ourport->port;
783 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
784 	irqreturn_t ret = IRQ_HANDLED;
785 
786 	if (pend & S3C64XX_UINTM_RXD_MSK) {
787 		ret = s3c24xx_serial_rx_chars(irq, id);
788 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
789 	}
790 	if (pend & S3C64XX_UINTM_TXD_MSK) {
791 		ret = s3c24xx_serial_tx_chars(irq, id);
792 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
793 	}
794 	return ret;
795 }
796 
797 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
798 {
799 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
800 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
801 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
802 
803 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
804 		if ((ufstat & info->tx_fifomask) != 0 ||
805 		    (ufstat & info->tx_fifofull))
806 			return 0;
807 
808 		return 1;
809 	}
810 
811 	return s3c24xx_serial_txempty_nofifo(port);
812 }
813 
814 /* no modem control lines */
815 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
816 {
817 	unsigned int umstat = rd_regb(port, S3C2410_UMSTAT);
818 
819 	if (umstat & S3C2410_UMSTAT_CTS)
820 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
821 	else
822 		return TIOCM_CAR | TIOCM_DSR;
823 }
824 
825 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
826 {
827 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
828 
829 	if (mctrl & TIOCM_RTS)
830 		umcon |= S3C2410_UMCOM_RTS_LOW;
831 	else
832 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
833 
834 	wr_regl(port, S3C2410_UMCON, umcon);
835 }
836 
837 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
838 {
839 	unsigned long flags;
840 	unsigned int ucon;
841 
842 	spin_lock_irqsave(&port->lock, flags);
843 
844 	ucon = rd_regl(port, S3C2410_UCON);
845 
846 	if (break_state)
847 		ucon |= S3C2410_UCON_SBREAK;
848 	else
849 		ucon &= ~S3C2410_UCON_SBREAK;
850 
851 	wr_regl(port, S3C2410_UCON, ucon);
852 
853 	spin_unlock_irqrestore(&port->lock, flags);
854 }
855 
856 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
857 {
858 	struct s3c24xx_uart_dma	*dma = p->dma;
859 	struct dma_slave_caps dma_caps;
860 	const char *reason = NULL;
861 	int ret;
862 
863 	/* Default slave configuration parameters */
864 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
865 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
866 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
867 	dma->rx_conf.src_maxburst	= 1;
868 
869 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
870 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
871 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
872 	dma->tx_conf.dst_maxburst	= 1;
873 
874 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
875 
876 	if (IS_ERR(dma->rx_chan)) {
877 		reason = "DMA RX channel request failed";
878 		ret = PTR_ERR(dma->rx_chan);
879 		goto err_warn;
880 	}
881 
882 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
883 	if (ret < 0 ||
884 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
885 		reason = "insufficient DMA RX engine capabilities";
886 		ret = -EOPNOTSUPP;
887 		goto err_release_rx;
888 	}
889 
890 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
891 
892 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
893 	if (IS_ERR(dma->tx_chan)) {
894 		reason = "DMA TX channel request failed";
895 		ret = PTR_ERR(dma->tx_chan);
896 		goto err_release_rx;
897 	}
898 
899 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
900 	if (ret < 0 ||
901 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
902 		reason = "insufficient DMA TX engine capabilities";
903 		ret = -EOPNOTSUPP;
904 		goto err_release_tx;
905 	}
906 
907 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
908 
909 	/* RX buffer */
910 	dma->rx_size = PAGE_SIZE;
911 
912 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
913 	if (!dma->rx_buf) {
914 		ret = -ENOMEM;
915 		goto err_release_tx;
916 	}
917 
918 	dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf,
919 				dma->rx_size, DMA_FROM_DEVICE);
920 	if (dma_mapping_error(p->port.dev, dma->rx_addr)) {
921 		reason = "DMA mapping error for RX buffer";
922 		ret = -EIO;
923 		goto err_free_rx;
924 	}
925 
926 	/* TX buffer */
927 	dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf,
928 				UART_XMIT_SIZE, DMA_TO_DEVICE);
929 	if (dma_mapping_error(p->port.dev, dma->tx_addr)) {
930 		reason = "DMA mapping error for TX buffer";
931 		ret = -EIO;
932 		goto err_unmap_rx;
933 	}
934 
935 	return 0;
936 
937 err_unmap_rx:
938 	dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size,
939 			 DMA_FROM_DEVICE);
940 err_free_rx:
941 	kfree(dma->rx_buf);
942 err_release_tx:
943 	dma_release_channel(dma->tx_chan);
944 err_release_rx:
945 	dma_release_channel(dma->rx_chan);
946 err_warn:
947 	if (reason)
948 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
949 	return ret;
950 }
951 
952 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
953 {
954 	struct s3c24xx_uart_dma	*dma = p->dma;
955 
956 	if (dma->rx_chan) {
957 		dmaengine_terminate_all(dma->rx_chan);
958 		dma_unmap_single(p->port.dev, dma->rx_addr,
959 				dma->rx_size, DMA_FROM_DEVICE);
960 		kfree(dma->rx_buf);
961 		dma_release_channel(dma->rx_chan);
962 		dma->rx_chan = NULL;
963 	}
964 
965 	if (dma->tx_chan) {
966 		dmaengine_terminate_all(dma->tx_chan);
967 		dma_unmap_single(p->port.dev, dma->tx_addr,
968 				UART_XMIT_SIZE, DMA_TO_DEVICE);
969 		dma_release_channel(dma->tx_chan);
970 		dma->tx_chan = NULL;
971 	}
972 }
973 
974 static void s3c24xx_serial_shutdown(struct uart_port *port)
975 {
976 	struct s3c24xx_uart_port *ourport = to_ourport(port);
977 
978 	if (ourport->tx_claimed) {
979 		if (!s3c24xx_serial_has_interrupt_mask(port))
980 			free_irq(ourport->tx_irq, ourport);
981 		tx_enabled(port) = 0;
982 		ourport->tx_claimed = 0;
983 		ourport->tx_mode = 0;
984 	}
985 
986 	if (ourport->rx_claimed) {
987 		if (!s3c24xx_serial_has_interrupt_mask(port))
988 			free_irq(ourport->rx_irq, ourport);
989 		ourport->rx_claimed = 0;
990 		rx_enabled(port) = 0;
991 	}
992 
993 	/* Clear pending interrupts and mask all interrupts */
994 	if (s3c24xx_serial_has_interrupt_mask(port)) {
995 		free_irq(port->irq, ourport);
996 
997 		wr_regl(port, S3C64XX_UINTP, 0xf);
998 		wr_regl(port, S3C64XX_UINTM, 0xf);
999 	}
1000 
1001 	if (ourport->dma)
1002 		s3c24xx_serial_release_dma(ourport);
1003 
1004 	ourport->tx_in_progress = 0;
1005 }
1006 
1007 static int s3c24xx_serial_startup(struct uart_port *port)
1008 {
1009 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1010 	int ret;
1011 
1012 	dbg("s3c24xx_serial_startup: port=%p (%08llx,%p)\n",
1013 	    port, (unsigned long long)port->mapbase, port->membase);
1014 
1015 	rx_enabled(port) = 1;
1016 
1017 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
1018 			  s3c24xx_serial_portname(port), ourport);
1019 
1020 	if (ret != 0) {
1021 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1022 		return ret;
1023 	}
1024 
1025 	ourport->rx_claimed = 1;
1026 
1027 	dbg("requesting tx irq...\n");
1028 
1029 	tx_enabled(port) = 1;
1030 
1031 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
1032 			  s3c24xx_serial_portname(port), ourport);
1033 
1034 	if (ret) {
1035 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1036 		goto err;
1037 	}
1038 
1039 	ourport->tx_claimed = 1;
1040 
1041 	dbg("s3c24xx_serial_startup ok\n");
1042 
1043 	/* the port reset code should have done the correct
1044 	 * register setup for the port controls */
1045 
1046 	return ret;
1047 
1048 err:
1049 	s3c24xx_serial_shutdown(port);
1050 	return ret;
1051 }
1052 
1053 static int s3c64xx_serial_startup(struct uart_port *port)
1054 {
1055 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1056 	unsigned long flags;
1057 	unsigned int ufcon;
1058 	int ret;
1059 
1060 	dbg("s3c64xx_serial_startup: port=%p (%08llx,%p)\n",
1061 	    port, (unsigned long long)port->mapbase, port->membase);
1062 
1063 	wr_regl(port, S3C64XX_UINTM, 0xf);
1064 	if (ourport->dma) {
1065 		ret = s3c24xx_serial_request_dma(ourport);
1066 		if (ret < 0) {
1067 			devm_kfree(port->dev, ourport->dma);
1068 			ourport->dma = NULL;
1069 		}
1070 	}
1071 
1072 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1073 			  s3c24xx_serial_portname(port), ourport);
1074 	if (ret) {
1075 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1076 		return ret;
1077 	}
1078 
1079 	/* For compatibility with s3c24xx Soc's */
1080 	rx_enabled(port) = 1;
1081 	ourport->rx_claimed = 1;
1082 	tx_enabled(port) = 0;
1083 	ourport->tx_claimed = 1;
1084 
1085 	spin_lock_irqsave(&port->lock, flags);
1086 
1087 	ufcon = rd_regl(port, S3C2410_UFCON);
1088 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1089 	if (!uart_console(port))
1090 		ufcon |= S3C2410_UFCON_RESETTX;
1091 	wr_regl(port, S3C2410_UFCON, ufcon);
1092 
1093 	enable_rx_pio(ourport);
1094 
1095 	spin_unlock_irqrestore(&port->lock, flags);
1096 
1097 	/* Enable Rx Interrupt */
1098 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1099 
1100 	dbg("s3c64xx_serial_startup ok\n");
1101 	return ret;
1102 }
1103 
1104 /* power power management control */
1105 
1106 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1107 			      unsigned int old)
1108 {
1109 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1110 	int timeout = 10000;
1111 
1112 	ourport->pm_level = level;
1113 
1114 	switch (level) {
1115 	case 3:
1116 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1117 			udelay(100);
1118 
1119 		if (!IS_ERR(ourport->baudclk))
1120 			clk_disable_unprepare(ourport->baudclk);
1121 
1122 		clk_disable_unprepare(ourport->clk);
1123 		break;
1124 
1125 	case 0:
1126 		clk_prepare_enable(ourport->clk);
1127 
1128 		if (!IS_ERR(ourport->baudclk))
1129 			clk_prepare_enable(ourport->baudclk);
1130 
1131 		break;
1132 	default:
1133 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1134 	}
1135 }
1136 
1137 /* baud rate calculation
1138  *
1139  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1140  * of different sources, including the peripheral clock ("pclk") and an
1141  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1142  * with a programmable extra divisor.
1143  *
1144  * The following code goes through the clock sources, and calculates the
1145  * baud clocks (and the resultant actual baud rates) and then tries to
1146  * pick the closest one and select that.
1147  *
1148 */
1149 
1150 #define MAX_CLK_NAME_LENGTH 15
1151 
1152 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1153 {
1154 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1155 	unsigned int ucon;
1156 
1157 	if (info->num_clks == 1)
1158 		return 0;
1159 
1160 	ucon = rd_regl(port, S3C2410_UCON);
1161 	ucon &= info->clksel_mask;
1162 	return ucon >> info->clksel_shift;
1163 }
1164 
1165 static void s3c24xx_serial_setsource(struct uart_port *port,
1166 			unsigned int clk_sel)
1167 {
1168 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1169 	unsigned int ucon;
1170 
1171 	if (info->num_clks == 1)
1172 		return;
1173 
1174 	ucon = rd_regl(port, S3C2410_UCON);
1175 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1176 		return;
1177 
1178 	ucon &= ~info->clksel_mask;
1179 	ucon |= clk_sel << info->clksel_shift;
1180 	wr_regl(port, S3C2410_UCON, ucon);
1181 }
1182 
1183 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1184 			unsigned int req_baud, struct clk **best_clk,
1185 			unsigned int *clk_num)
1186 {
1187 	struct s3c24xx_uart_info *info = ourport->info;
1188 	struct clk *clk;
1189 	unsigned long rate;
1190 	unsigned int cnt, baud, quot, clk_sel, best_quot = 0;
1191 	char clkname[MAX_CLK_NAME_LENGTH];
1192 	int calc_deviation, deviation = (1 << 30) - 1;
1193 
1194 	clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel :
1195 			ourport->info->def_clk_sel;
1196 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1197 		if (!(clk_sel & (1 << cnt)))
1198 			continue;
1199 
1200 		sprintf(clkname, "clk_uart_baud%d", cnt);
1201 		clk = clk_get(ourport->port.dev, clkname);
1202 		if (IS_ERR(clk))
1203 			continue;
1204 
1205 		rate = clk_get_rate(clk);
1206 		if (!rate)
1207 			continue;
1208 
1209 		if (ourport->info->has_divslot) {
1210 			unsigned long div = rate / req_baud;
1211 
1212 			/* The UDIVSLOT register on the newer UARTs allows us to
1213 			 * get a divisor adjustment of 1/16th on the baud clock.
1214 			 *
1215 			 * We don't keep the UDIVSLOT value (the 16ths we
1216 			 * calculated by not multiplying the baud by 16) as it
1217 			 * is easy enough to recalculate.
1218 			 */
1219 
1220 			quot = div / 16;
1221 			baud = rate / div;
1222 		} else {
1223 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1224 			baud = rate / (quot * 16);
1225 		}
1226 		quot--;
1227 
1228 		calc_deviation = req_baud - baud;
1229 		if (calc_deviation < 0)
1230 			calc_deviation = -calc_deviation;
1231 
1232 		if (calc_deviation < deviation) {
1233 			*best_clk = clk;
1234 			best_quot = quot;
1235 			*clk_num = cnt;
1236 			deviation = calc_deviation;
1237 		}
1238 	}
1239 
1240 	return best_quot;
1241 }
1242 
1243 /* udivslot_table[]
1244  *
1245  * This table takes the fractional value of the baud divisor and gives
1246  * the recommended setting for the UDIVSLOT register.
1247  */
1248 static u16 udivslot_table[16] = {
1249 	[0] = 0x0000,
1250 	[1] = 0x0080,
1251 	[2] = 0x0808,
1252 	[3] = 0x0888,
1253 	[4] = 0x2222,
1254 	[5] = 0x4924,
1255 	[6] = 0x4A52,
1256 	[7] = 0x54AA,
1257 	[8] = 0x5555,
1258 	[9] = 0xD555,
1259 	[10] = 0xD5D5,
1260 	[11] = 0xDDD5,
1261 	[12] = 0xDDDD,
1262 	[13] = 0xDFDD,
1263 	[14] = 0xDFDF,
1264 	[15] = 0xFFDF,
1265 };
1266 
1267 static void s3c24xx_serial_set_termios(struct uart_port *port,
1268 				       struct ktermios *termios,
1269 				       struct ktermios *old)
1270 {
1271 	struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1272 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1273 	struct clk *clk = ERR_PTR(-EINVAL);
1274 	unsigned long flags;
1275 	unsigned int baud, quot, clk_sel = 0;
1276 	unsigned int ulcon;
1277 	unsigned int umcon;
1278 	unsigned int udivslot = 0;
1279 
1280 	/*
1281 	 * We don't support modem control lines.
1282 	 */
1283 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1284 	termios->c_cflag |= CLOCAL;
1285 
1286 	/*
1287 	 * Ask the core to calculate the divisor for us.
1288 	 */
1289 
1290 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1291 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1292 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1293 		quot = port->custom_divisor;
1294 	if (IS_ERR(clk))
1295 		return;
1296 
1297 	/* check to see if we need  to change clock source */
1298 
1299 	if (ourport->baudclk != clk) {
1300 		clk_prepare_enable(clk);
1301 
1302 		s3c24xx_serial_setsource(port, clk_sel);
1303 
1304 		if (!IS_ERR(ourport->baudclk)) {
1305 			clk_disable_unprepare(ourport->baudclk);
1306 			ourport->baudclk = ERR_PTR(-EINVAL);
1307 		}
1308 
1309 		ourport->baudclk = clk;
1310 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1311 	}
1312 
1313 	if (ourport->info->has_divslot) {
1314 		unsigned int div = ourport->baudclk_rate / baud;
1315 
1316 		if (cfg->has_fracval) {
1317 			udivslot = (div & 15);
1318 			dbg("fracval = %04x\n", udivslot);
1319 		} else {
1320 			udivslot = udivslot_table[div & 15];
1321 			dbg("udivslot = %04x (div %d)\n", udivslot, div & 15);
1322 		}
1323 	}
1324 
1325 	switch (termios->c_cflag & CSIZE) {
1326 	case CS5:
1327 		dbg("config: 5bits/char\n");
1328 		ulcon = S3C2410_LCON_CS5;
1329 		break;
1330 	case CS6:
1331 		dbg("config: 6bits/char\n");
1332 		ulcon = S3C2410_LCON_CS6;
1333 		break;
1334 	case CS7:
1335 		dbg("config: 7bits/char\n");
1336 		ulcon = S3C2410_LCON_CS7;
1337 		break;
1338 	case CS8:
1339 	default:
1340 		dbg("config: 8bits/char\n");
1341 		ulcon = S3C2410_LCON_CS8;
1342 		break;
1343 	}
1344 
1345 	/* preserve original lcon IR settings */
1346 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1347 
1348 	if (termios->c_cflag & CSTOPB)
1349 		ulcon |= S3C2410_LCON_STOPB;
1350 
1351 	if (termios->c_cflag & PARENB) {
1352 		if (termios->c_cflag & PARODD)
1353 			ulcon |= S3C2410_LCON_PODD;
1354 		else
1355 			ulcon |= S3C2410_LCON_PEVEN;
1356 	} else {
1357 		ulcon |= S3C2410_LCON_PNONE;
1358 	}
1359 
1360 	spin_lock_irqsave(&port->lock, flags);
1361 
1362 	dbg("setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1363 	    ulcon, quot, udivslot);
1364 
1365 	wr_regl(port, S3C2410_ULCON, ulcon);
1366 	wr_regl(port, S3C2410_UBRDIV, quot);
1367 
1368 	port->status &= ~UPSTAT_AUTOCTS;
1369 
1370 	umcon = rd_regl(port, S3C2410_UMCON);
1371 	if (termios->c_cflag & CRTSCTS) {
1372 		umcon |= S3C2410_UMCOM_AFC;
1373 		/* Disable RTS when RX FIFO contains 63 bytes */
1374 		umcon &= ~S3C2412_UMCON_AFC_8;
1375 		port->status = UPSTAT_AUTOCTS;
1376 	} else {
1377 		umcon &= ~S3C2410_UMCOM_AFC;
1378 	}
1379 	wr_regl(port, S3C2410_UMCON, umcon);
1380 
1381 	if (ourport->info->has_divslot)
1382 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1383 
1384 	dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1385 	    rd_regl(port, S3C2410_ULCON),
1386 	    rd_regl(port, S3C2410_UCON),
1387 	    rd_regl(port, S3C2410_UFCON));
1388 
1389 	/*
1390 	 * Update the per-port timeout.
1391 	 */
1392 	uart_update_timeout(port, termios->c_cflag, baud);
1393 
1394 	/*
1395 	 * Which character status flags are we interested in?
1396 	 */
1397 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1398 	if (termios->c_iflag & INPCK)
1399 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1400 			S3C2410_UERSTAT_PARITY;
1401 	/*
1402 	 * Which character status flags should we ignore?
1403 	 */
1404 	port->ignore_status_mask = 0;
1405 	if (termios->c_iflag & IGNPAR)
1406 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1407 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1408 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1409 
1410 	/*
1411 	 * Ignore all characters if CREAD is not set.
1412 	 */
1413 	if ((termios->c_cflag & CREAD) == 0)
1414 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1415 
1416 	spin_unlock_irqrestore(&port->lock, flags);
1417 }
1418 
1419 static const char *s3c24xx_serial_type(struct uart_port *port)
1420 {
1421 	switch (port->type) {
1422 	case PORT_S3C2410:
1423 		return "S3C2410";
1424 	case PORT_S3C2440:
1425 		return "S3C2440";
1426 	case PORT_S3C2412:
1427 		return "S3C2412";
1428 	case PORT_S3C6400:
1429 		return "S3C6400/10";
1430 	default:
1431 		return NULL;
1432 	}
1433 }
1434 
1435 #define MAP_SIZE (0x100)
1436 
1437 static void s3c24xx_serial_release_port(struct uart_port *port)
1438 {
1439 	release_mem_region(port->mapbase, MAP_SIZE);
1440 }
1441 
1442 static int s3c24xx_serial_request_port(struct uart_port *port)
1443 {
1444 	const char *name = s3c24xx_serial_portname(port);
1445 	return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
1446 }
1447 
1448 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1449 {
1450 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1451 
1452 	if (flags & UART_CONFIG_TYPE &&
1453 	    s3c24xx_serial_request_port(port) == 0)
1454 		port->type = info->type;
1455 }
1456 
1457 /*
1458  * verify the new serial_struct (for TIOCSSERIAL).
1459  */
1460 static int
1461 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1462 {
1463 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1464 
1465 	if (ser->type != PORT_UNKNOWN && ser->type != info->type)
1466 		return -EINVAL;
1467 
1468 	return 0;
1469 }
1470 
1471 
1472 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1473 
1474 static struct console s3c24xx_serial_console;
1475 
1476 static int __init s3c24xx_serial_console_init(void)
1477 {
1478 	register_console(&s3c24xx_serial_console);
1479 	return 0;
1480 }
1481 console_initcall(s3c24xx_serial_console_init);
1482 
1483 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1484 #else
1485 #define S3C24XX_SERIAL_CONSOLE NULL
1486 #endif
1487 
1488 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1489 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1490 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1491 			 unsigned char c);
1492 #endif
1493 
1494 static struct uart_ops s3c24xx_serial_ops = {
1495 	.pm		= s3c24xx_serial_pm,
1496 	.tx_empty	= s3c24xx_serial_tx_empty,
1497 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1498 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1499 	.stop_tx	= s3c24xx_serial_stop_tx,
1500 	.start_tx	= s3c24xx_serial_start_tx,
1501 	.stop_rx	= s3c24xx_serial_stop_rx,
1502 	.break_ctl	= s3c24xx_serial_break_ctl,
1503 	.startup	= s3c24xx_serial_startup,
1504 	.shutdown	= s3c24xx_serial_shutdown,
1505 	.set_termios	= s3c24xx_serial_set_termios,
1506 	.type		= s3c24xx_serial_type,
1507 	.release_port	= s3c24xx_serial_release_port,
1508 	.request_port	= s3c24xx_serial_request_port,
1509 	.config_port	= s3c24xx_serial_config_port,
1510 	.verify_port	= s3c24xx_serial_verify_port,
1511 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1512 	.poll_get_char = s3c24xx_serial_get_poll_char,
1513 	.poll_put_char = s3c24xx_serial_put_poll_char,
1514 #endif
1515 };
1516 
1517 static struct uart_driver s3c24xx_uart_drv = {
1518 	.owner		= THIS_MODULE,
1519 	.driver_name	= "s3c2410_serial",
1520 	.nr		= CONFIG_SERIAL_SAMSUNG_UARTS,
1521 	.cons		= S3C24XX_SERIAL_CONSOLE,
1522 	.dev_name	= S3C24XX_SERIAL_NAME,
1523 	.major		= S3C24XX_SERIAL_MAJOR,
1524 	.minor		= S3C24XX_SERIAL_MINOR,
1525 };
1526 
1527 #define __PORT_LOCK_UNLOCKED(i) \
1528 	__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[i].port.lock)
1529 static struct s3c24xx_uart_port
1530 s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
1531 	[0] = {
1532 		.port = {
1533 			.lock		= __PORT_LOCK_UNLOCKED(0),
1534 			.iotype		= UPIO_MEM,
1535 			.uartclk	= 0,
1536 			.fifosize	= 16,
1537 			.ops		= &s3c24xx_serial_ops,
1538 			.flags		= UPF_BOOT_AUTOCONF,
1539 			.line		= 0,
1540 		}
1541 	},
1542 	[1] = {
1543 		.port = {
1544 			.lock		= __PORT_LOCK_UNLOCKED(1),
1545 			.iotype		= UPIO_MEM,
1546 			.uartclk	= 0,
1547 			.fifosize	= 16,
1548 			.ops		= &s3c24xx_serial_ops,
1549 			.flags		= UPF_BOOT_AUTOCONF,
1550 			.line		= 1,
1551 		}
1552 	},
1553 #if CONFIG_SERIAL_SAMSUNG_UARTS > 2
1554 
1555 	[2] = {
1556 		.port = {
1557 			.lock		= __PORT_LOCK_UNLOCKED(2),
1558 			.iotype		= UPIO_MEM,
1559 			.uartclk	= 0,
1560 			.fifosize	= 16,
1561 			.ops		= &s3c24xx_serial_ops,
1562 			.flags		= UPF_BOOT_AUTOCONF,
1563 			.line		= 2,
1564 		}
1565 	},
1566 #endif
1567 #if CONFIG_SERIAL_SAMSUNG_UARTS > 3
1568 	[3] = {
1569 		.port = {
1570 			.lock		= __PORT_LOCK_UNLOCKED(3),
1571 			.iotype		= UPIO_MEM,
1572 			.uartclk	= 0,
1573 			.fifosize	= 16,
1574 			.ops		= &s3c24xx_serial_ops,
1575 			.flags		= UPF_BOOT_AUTOCONF,
1576 			.line		= 3,
1577 		}
1578 	}
1579 #endif
1580 };
1581 #undef __PORT_LOCK_UNLOCKED
1582 
1583 /* s3c24xx_serial_resetport
1584  *
1585  * reset the fifos and other the settings.
1586 */
1587 
1588 static void s3c24xx_serial_resetport(struct uart_port *port,
1589 				   struct s3c2410_uartcfg *cfg)
1590 {
1591 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1592 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1593 	unsigned int ucon_mask;
1594 
1595 	ucon_mask = info->clksel_mask;
1596 	if (info->type == PORT_S3C2440)
1597 		ucon_mask |= S3C2440_UCON0_DIVMASK;
1598 
1599 	ucon &= ucon_mask;
1600 	wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
1601 
1602 	/* reset both fifos */
1603 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1604 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1605 
1606 	/* some delay is required after fifo reset */
1607 	udelay(1);
1608 }
1609 
1610 
1611 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1612 
1613 static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1614 					     unsigned long val, void *data)
1615 {
1616 	struct s3c24xx_uart_port *port;
1617 	struct uart_port *uport;
1618 
1619 	port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1620 	uport = &port->port;
1621 
1622 	/* check to see if port is enabled */
1623 
1624 	if (port->pm_level != 0)
1625 		return 0;
1626 
1627 	/* try and work out if the baudrate is changing, we can detect
1628 	 * a change in rate, but we do not have support for detecting
1629 	 * a disturbance in the clock-rate over the change.
1630 	 */
1631 
1632 	if (IS_ERR(port->baudclk))
1633 		goto exit;
1634 
1635 	if (port->baudclk_rate == clk_get_rate(port->baudclk))
1636 		goto exit;
1637 
1638 	if (val == CPUFREQ_PRECHANGE) {
1639 		/* we should really shut the port down whilst the
1640 		 * frequency change is in progress. */
1641 
1642 	} else if (val == CPUFREQ_POSTCHANGE) {
1643 		struct ktermios *termios;
1644 		struct tty_struct *tty;
1645 
1646 		if (uport->state == NULL)
1647 			goto exit;
1648 
1649 		tty = uport->state->port.tty;
1650 
1651 		if (tty == NULL)
1652 			goto exit;
1653 
1654 		termios = &tty->termios;
1655 
1656 		if (termios == NULL) {
1657 			dev_warn(uport->dev, "%s: no termios?\n", __func__);
1658 			goto exit;
1659 		}
1660 
1661 		s3c24xx_serial_set_termios(uport, termios, NULL);
1662 	}
1663 
1664 exit:
1665 	return 0;
1666 }
1667 
1668 static inline int
1669 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1670 {
1671 	port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1672 
1673 	return cpufreq_register_notifier(&port->freq_transition,
1674 					 CPUFREQ_TRANSITION_NOTIFIER);
1675 }
1676 
1677 static inline void
1678 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1679 {
1680 	cpufreq_unregister_notifier(&port->freq_transition,
1681 				    CPUFREQ_TRANSITION_NOTIFIER);
1682 }
1683 
1684 #else
1685 static inline int
1686 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1687 {
1688 	return 0;
1689 }
1690 
1691 static inline void
1692 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1693 {
1694 }
1695 #endif
1696 
1697 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1698 {
1699 	struct device *dev = ourport->port.dev;
1700 	struct s3c24xx_uart_info *info = ourport->info;
1701 	char clk_name[MAX_CLK_NAME_LENGTH];
1702 	unsigned int clk_sel;
1703 	struct clk *clk;
1704 	int clk_num;
1705 	int ret;
1706 
1707 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1708 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1709 		if (!(clk_sel & (1 << clk_num)))
1710 			continue;
1711 
1712 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1713 		clk = clk_get(dev, clk_name);
1714 		if (IS_ERR(clk))
1715 			continue;
1716 
1717 		ret = clk_prepare_enable(clk);
1718 		if (ret) {
1719 			clk_put(clk);
1720 			continue;
1721 		}
1722 
1723 		ourport->baudclk = clk;
1724 		ourport->baudclk_rate = clk_get_rate(clk);
1725 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1726 
1727 		return 0;
1728 	}
1729 
1730 	return -EINVAL;
1731 }
1732 
1733 /* s3c24xx_serial_init_port
1734  *
1735  * initialise a single serial port from the platform device given
1736  */
1737 
1738 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1739 				    struct platform_device *platdev)
1740 {
1741 	struct uart_port *port = &ourport->port;
1742 	struct s3c2410_uartcfg *cfg = ourport->cfg;
1743 	struct resource *res;
1744 	int ret;
1745 
1746 	dbg("s3c24xx_serial_init_port: port=%p, platdev=%p\n", port, platdev);
1747 
1748 	if (platdev == NULL)
1749 		return -ENODEV;
1750 
1751 	if (port->mapbase != 0)
1752 		return -EINVAL;
1753 
1754 	/* setup info for port */
1755 	port->dev	= &platdev->dev;
1756 
1757 	/* Startup sequence is different for s3c64xx and higher SoC's */
1758 	if (s3c24xx_serial_has_interrupt_mask(port))
1759 		s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
1760 
1761 	port->uartclk = 1;
1762 
1763 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1764 		dbg("s3c24xx_serial_init_port: enabling flow control\n");
1765 		port->flags |= UPF_CONS_FLOW;
1766 	}
1767 
1768 	/* sort our the physical and virtual addresses for each UART */
1769 
1770 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1771 	if (res == NULL) {
1772 		dev_err(port->dev, "failed to find memory resource for uart\n");
1773 		return -EINVAL;
1774 	}
1775 
1776 	dbg("resource %pR)\n", res);
1777 
1778 	port->membase = devm_ioremap(port->dev, res->start, resource_size(res));
1779 	if (!port->membase) {
1780 		dev_err(port->dev, "failed to remap controller address\n");
1781 		return -EBUSY;
1782 	}
1783 
1784 	port->mapbase = res->start;
1785 	ret = platform_get_irq(platdev, 0);
1786 	if (ret < 0)
1787 		port->irq = 0;
1788 	else {
1789 		port->irq = ret;
1790 		ourport->rx_irq = ret;
1791 		ourport->tx_irq = ret + 1;
1792 	}
1793 
1794 	ret = platform_get_irq(platdev, 1);
1795 	if (ret > 0)
1796 		ourport->tx_irq = ret;
1797 	/*
1798 	 * DMA is currently supported only on DT platforms, if DMA properties
1799 	 * are specified.
1800 	 */
1801 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1802 						     "dmas", NULL)) {
1803 		ourport->dma = devm_kzalloc(port->dev,
1804 					    sizeof(*ourport->dma),
1805 					    GFP_KERNEL);
1806 		if (!ourport->dma) {
1807 			ret = -ENOMEM;
1808 			goto err;
1809 		}
1810 	}
1811 
1812 	ourport->clk	= clk_get(&platdev->dev, "uart");
1813 	if (IS_ERR(ourport->clk)) {
1814 		pr_err("%s: Controller clock not found\n",
1815 				dev_name(&platdev->dev));
1816 		ret = PTR_ERR(ourport->clk);
1817 		goto err;
1818 	}
1819 
1820 	ret = clk_prepare_enable(ourport->clk);
1821 	if (ret) {
1822 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1823 		clk_put(ourport->clk);
1824 		goto err;
1825 	}
1826 
1827 	ret = s3c24xx_serial_enable_baudclk(ourport);
1828 	if (ret)
1829 		pr_warn("uart: failed to enable baudclk\n");
1830 
1831 	/* Keep all interrupts masked and cleared */
1832 	if (s3c24xx_serial_has_interrupt_mask(port)) {
1833 		wr_regl(port, S3C64XX_UINTM, 0xf);
1834 		wr_regl(port, S3C64XX_UINTP, 0xf);
1835 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1836 	}
1837 
1838 	dbg("port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1839 	    &port->mapbase, port->membase, port->irq,
1840 	    ourport->rx_irq, ourport->tx_irq, port->uartclk);
1841 
1842 	/* reset the fifos (and setup the uart) */
1843 	s3c24xx_serial_resetport(port, cfg);
1844 
1845 	return 0;
1846 
1847 err:
1848 	port->mapbase = 0;
1849 	return ret;
1850 }
1851 
1852 /* Device driver serial port probe */
1853 
1854 static const struct of_device_id s3c24xx_uart_dt_match[];
1855 static int probe_index;
1856 
1857 static inline struct s3c24xx_serial_drv_data *s3c24xx_get_driver_data(
1858 			struct platform_device *pdev)
1859 {
1860 #ifdef CONFIG_OF
1861 	if (pdev->dev.of_node) {
1862 		const struct of_device_id *match;
1863 		match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
1864 		return (struct s3c24xx_serial_drv_data *)match->data;
1865 	}
1866 #endif
1867 	return (struct s3c24xx_serial_drv_data *)
1868 			platform_get_device_id(pdev)->driver_data;
1869 }
1870 
1871 static int s3c24xx_serial_probe(struct platform_device *pdev)
1872 {
1873 	struct device_node *np = pdev->dev.of_node;
1874 	struct s3c24xx_uart_port *ourport;
1875 	int index = probe_index;
1876 	int ret;
1877 
1878 	if (np) {
1879 		ret = of_alias_get_id(np, "serial");
1880 		if (ret >= 0)
1881 			index = ret;
1882 	}
1883 
1884 	dbg("s3c24xx_serial_probe(%p) %d\n", pdev, index);
1885 
1886 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
1887 		dev_err(&pdev->dev, "serial%d out of range\n", index);
1888 		return -EINVAL;
1889 	}
1890 	ourport = &s3c24xx_serial_ports[index];
1891 
1892 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
1893 	if (!ourport->drv_data) {
1894 		dev_err(&pdev->dev, "could not find driver data\n");
1895 		return -ENODEV;
1896 	}
1897 
1898 	ourport->baudclk = ERR_PTR(-EINVAL);
1899 	ourport->info = ourport->drv_data->info;
1900 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1901 			dev_get_platdata(&pdev->dev) :
1902 			ourport->drv_data->def_cfg;
1903 
1904 	if (np)
1905 		of_property_read_u32(np,
1906 			"samsung,uart-fifosize", &ourport->port.fifosize);
1907 
1908 	if (ourport->drv_data->fifosize[index])
1909 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
1910 	else if (ourport->info->fifosize)
1911 		ourport->port.fifosize = ourport->info->fifosize;
1912 
1913 	/*
1914 	 * DMA transfers must be aligned at least to cache line size,
1915 	 * so find minimal transfer size suitable for DMA mode
1916 	 */
1917 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
1918 				    dma_get_cache_alignment());
1919 
1920 	dbg("%s: initialising port %p...\n", __func__, ourport);
1921 
1922 	ret = s3c24xx_serial_init_port(ourport, pdev);
1923 	if (ret < 0)
1924 		return ret;
1925 
1926 	if (!s3c24xx_uart_drv.state) {
1927 		ret = uart_register_driver(&s3c24xx_uart_drv);
1928 		if (ret < 0) {
1929 			pr_err("Failed to register Samsung UART driver\n");
1930 			return ret;
1931 		}
1932 	}
1933 
1934 	dbg("%s: adding port\n", __func__);
1935 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
1936 	platform_set_drvdata(pdev, &ourport->port);
1937 
1938 	/*
1939 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
1940 	 * so that a potential re-enablement through the pm-callback overlaps
1941 	 * and keeps the clock enabled in this case.
1942 	 */
1943 	clk_disable_unprepare(ourport->clk);
1944 	if (!IS_ERR(ourport->baudclk))
1945 		clk_disable_unprepare(ourport->baudclk);
1946 
1947 	ret = s3c24xx_serial_cpufreq_register(ourport);
1948 	if (ret < 0)
1949 		dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
1950 
1951 	probe_index++;
1952 
1953 	return 0;
1954 }
1955 
1956 static int s3c24xx_serial_remove(struct platform_device *dev)
1957 {
1958 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
1959 
1960 	if (port) {
1961 		s3c24xx_serial_cpufreq_deregister(to_ourport(port));
1962 		uart_remove_one_port(&s3c24xx_uart_drv, port);
1963 	}
1964 
1965 	uart_unregister_driver(&s3c24xx_uart_drv);
1966 
1967 	return 0;
1968 }
1969 
1970 /* UART power management code */
1971 #ifdef CONFIG_PM_SLEEP
1972 static int s3c24xx_serial_suspend(struct device *dev)
1973 {
1974 	struct uart_port *port = s3c24xx_dev_to_port(dev);
1975 
1976 	if (port)
1977 		uart_suspend_port(&s3c24xx_uart_drv, port);
1978 
1979 	return 0;
1980 }
1981 
1982 static int s3c24xx_serial_resume(struct device *dev)
1983 {
1984 	struct uart_port *port = s3c24xx_dev_to_port(dev);
1985 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1986 
1987 	if (port) {
1988 		clk_prepare_enable(ourport->clk);
1989 		if (!IS_ERR(ourport->baudclk))
1990 			clk_prepare_enable(ourport->baudclk);
1991 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
1992 		if (!IS_ERR(ourport->baudclk))
1993 			clk_disable_unprepare(ourport->baudclk);
1994 		clk_disable_unprepare(ourport->clk);
1995 
1996 		uart_resume_port(&s3c24xx_uart_drv, port);
1997 	}
1998 
1999 	return 0;
2000 }
2001 
2002 static int s3c24xx_serial_resume_noirq(struct device *dev)
2003 {
2004 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2005 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2006 
2007 	if (port) {
2008 		/* restore IRQ mask */
2009 		if (s3c24xx_serial_has_interrupt_mask(port)) {
2010 			unsigned int uintm = 0xf;
2011 			if (tx_enabled(port))
2012 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2013 			if (rx_enabled(port))
2014 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2015 			clk_prepare_enable(ourport->clk);
2016 			if (!IS_ERR(ourport->baudclk))
2017 				clk_prepare_enable(ourport->baudclk);
2018 			wr_regl(port, S3C64XX_UINTM, uintm);
2019 			if (!IS_ERR(ourport->baudclk))
2020 				clk_disable_unprepare(ourport->baudclk);
2021 			clk_disable_unprepare(ourport->clk);
2022 		}
2023 	}
2024 
2025 	return 0;
2026 }
2027 
2028 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2029 	.suspend = s3c24xx_serial_suspend,
2030 	.resume = s3c24xx_serial_resume,
2031 	.resume_noirq = s3c24xx_serial_resume_noirq,
2032 };
2033 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2034 
2035 #else /* !CONFIG_PM_SLEEP */
2036 
2037 #define SERIAL_SAMSUNG_PM_OPS	NULL
2038 #endif /* CONFIG_PM_SLEEP */
2039 
2040 /* Console code */
2041 
2042 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2043 
2044 static struct uart_port *cons_uart;
2045 
2046 static int
2047 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2048 {
2049 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2050 	unsigned long ufstat, utrstat;
2051 
2052 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2053 		/* fifo mode - check amount of data in fifo registers... */
2054 
2055 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2056 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2057 	}
2058 
2059 	/* in non-fifo mode, we go and use the tx buffer empty */
2060 
2061 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2062 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2063 }
2064 
2065 static bool
2066 s3c24xx_port_configured(unsigned int ucon)
2067 {
2068 	/* consider the serial port configured if the tx/rx mode set */
2069 	return (ucon & 0xf) != 0;
2070 }
2071 
2072 #ifdef CONFIG_CONSOLE_POLL
2073 /*
2074  * Console polling routines for writing and reading from the uart while
2075  * in an interrupt or debug context.
2076  */
2077 
2078 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2079 {
2080 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2081 	unsigned int ufstat;
2082 
2083 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2084 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2085 		return NO_POLL_CHAR;
2086 
2087 	return rd_regb(port, S3C2410_URXH);
2088 }
2089 
2090 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2091 		unsigned char c)
2092 {
2093 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2094 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2095 
2096 	/* not possible to xmit on unconfigured port */
2097 	if (!s3c24xx_port_configured(ucon))
2098 		return;
2099 
2100 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2101 		cpu_relax();
2102 	wr_regb(port, S3C2410_UTXH, c);
2103 }
2104 
2105 #endif /* CONFIG_CONSOLE_POLL */
2106 
2107 static void
2108 s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
2109 {
2110 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2111 
2112 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2113 		cpu_relax();
2114 	wr_regb(port, S3C2410_UTXH, ch);
2115 }
2116 
2117 static void
2118 s3c24xx_serial_console_write(struct console *co, const char *s,
2119 			     unsigned int count)
2120 {
2121 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2122 
2123 	/* not possible to xmit on unconfigured port */
2124 	if (!s3c24xx_port_configured(ucon))
2125 		return;
2126 
2127 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2128 }
2129 
2130 static void __init
2131 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2132 			   int *parity, int *bits)
2133 {
2134 	struct clk *clk;
2135 	unsigned int ulcon;
2136 	unsigned int ucon;
2137 	unsigned int ubrdiv;
2138 	unsigned long rate;
2139 	unsigned int clk_sel;
2140 	char clk_name[MAX_CLK_NAME_LENGTH];
2141 
2142 	ulcon  = rd_regl(port, S3C2410_ULCON);
2143 	ucon   = rd_regl(port, S3C2410_UCON);
2144 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2145 
2146 	dbg("s3c24xx_serial_get_options: port=%p\n"
2147 	    "registers: ulcon=%08x, ucon=%08x, ubdriv=%08x\n",
2148 	    port, ulcon, ucon, ubrdiv);
2149 
2150 	if (s3c24xx_port_configured(ucon)) {
2151 		switch (ulcon & S3C2410_LCON_CSMASK) {
2152 		case S3C2410_LCON_CS5:
2153 			*bits = 5;
2154 			break;
2155 		case S3C2410_LCON_CS6:
2156 			*bits = 6;
2157 			break;
2158 		case S3C2410_LCON_CS7:
2159 			*bits = 7;
2160 			break;
2161 		case S3C2410_LCON_CS8:
2162 		default:
2163 			*bits = 8;
2164 			break;
2165 		}
2166 
2167 		switch (ulcon & S3C2410_LCON_PMASK) {
2168 		case S3C2410_LCON_PEVEN:
2169 			*parity = 'e';
2170 			break;
2171 
2172 		case S3C2410_LCON_PODD:
2173 			*parity = 'o';
2174 			break;
2175 
2176 		case S3C2410_LCON_PNONE:
2177 		default:
2178 			*parity = 'n';
2179 		}
2180 
2181 		/* now calculate the baud rate */
2182 
2183 		clk_sel = s3c24xx_serial_getsource(port);
2184 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2185 
2186 		clk = clk_get(port->dev, clk_name);
2187 		if (!IS_ERR(clk))
2188 			rate = clk_get_rate(clk);
2189 		else
2190 			rate = 1;
2191 
2192 		*baud = rate / (16 * (ubrdiv + 1));
2193 		dbg("calculated baud %d\n", *baud);
2194 	}
2195 
2196 }
2197 
2198 static int __init
2199 s3c24xx_serial_console_setup(struct console *co, char *options)
2200 {
2201 	struct uart_port *port;
2202 	int baud = 9600;
2203 	int bits = 8;
2204 	int parity = 'n';
2205 	int flow = 'n';
2206 
2207 	dbg("s3c24xx_serial_console_setup: co=%p (%d), %s\n",
2208 	    co, co->index, options);
2209 
2210 	/* is this a valid port */
2211 
2212 	if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
2213 		co->index = 0;
2214 
2215 	port = &s3c24xx_serial_ports[co->index].port;
2216 
2217 	/* is the port configured? */
2218 
2219 	if (port->mapbase == 0x0)
2220 		return -ENODEV;
2221 
2222 	cons_uart = port;
2223 
2224 	dbg("s3c24xx_serial_console_setup: port=%p (%d)\n", port, co->index);
2225 
2226 	/*
2227 	 * Check whether an invalid uart number has been specified, and
2228 	 * if so, search for the first available port that does have
2229 	 * console support.
2230 	 */
2231 	if (options)
2232 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2233 	else
2234 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2235 
2236 	dbg("s3c24xx_serial_console_setup: baud %d\n", baud);
2237 
2238 	return uart_set_options(port, co, baud, parity, bits, flow);
2239 }
2240 
2241 static struct console s3c24xx_serial_console = {
2242 	.name		= S3C24XX_SERIAL_NAME,
2243 	.device		= uart_console_device,
2244 	.flags		= CON_PRINTBUFFER,
2245 	.index		= -1,
2246 	.write		= s3c24xx_serial_console_write,
2247 	.setup		= s3c24xx_serial_console_setup,
2248 	.data		= &s3c24xx_uart_drv,
2249 };
2250 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2251 
2252 #ifdef CONFIG_CPU_S3C2410
2253 static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
2254 	.info = &(struct s3c24xx_uart_info) {
2255 		.name		= "Samsung S3C2410 UART",
2256 		.type		= PORT_S3C2410,
2257 		.fifosize	= 16,
2258 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2259 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2260 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2261 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2262 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2263 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2264 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2265 		.num_clks	= 2,
2266 		.clksel_mask	= S3C2410_UCON_CLKMASK,
2267 		.clksel_shift	= S3C2410_UCON_CLKSHIFT,
2268 	},
2269 	.def_cfg = &(struct s3c2410_uartcfg) {
2270 		.ucon		= S3C2410_UCON_DEFAULT,
2271 		.ufcon		= S3C2410_UFCON_DEFAULT,
2272 	},
2273 };
2274 #define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
2275 #else
2276 #define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2277 #endif
2278 
2279 #ifdef CONFIG_CPU_S3C2412
2280 static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
2281 	.info = &(struct s3c24xx_uart_info) {
2282 		.name		= "Samsung S3C2412 UART",
2283 		.type		= PORT_S3C2412,
2284 		.fifosize	= 64,
2285 		.has_divslot	= 1,
2286 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2287 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2288 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2289 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2290 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2291 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2292 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2293 		.num_clks	= 4,
2294 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2295 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2296 	},
2297 	.def_cfg = &(struct s3c2410_uartcfg) {
2298 		.ucon		= S3C2410_UCON_DEFAULT,
2299 		.ufcon		= S3C2410_UFCON_DEFAULT,
2300 	},
2301 };
2302 #define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
2303 #else
2304 #define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2305 #endif
2306 
2307 #if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
2308 	defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
2309 static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
2310 	.info = &(struct s3c24xx_uart_info) {
2311 		.name		= "Samsung S3C2440 UART",
2312 		.type		= PORT_S3C2440,
2313 		.fifosize	= 64,
2314 		.has_divslot	= 1,
2315 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2316 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2317 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2318 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2319 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2320 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2321 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2322 		.num_clks	= 4,
2323 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2324 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2325 	},
2326 	.def_cfg = &(struct s3c2410_uartcfg) {
2327 		.ucon		= S3C2410_UCON_DEFAULT,
2328 		.ufcon		= S3C2410_UFCON_DEFAULT,
2329 	},
2330 };
2331 #define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
2332 #else
2333 #define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2334 #endif
2335 
2336 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2337 static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2338 	.info = &(struct s3c24xx_uart_info) {
2339 		.name		= "Samsung S3C6400 UART",
2340 		.type		= PORT_S3C6400,
2341 		.fifosize	= 64,
2342 		.has_divslot	= 1,
2343 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2344 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2345 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2346 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2347 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2348 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2349 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2350 		.num_clks	= 4,
2351 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2352 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2353 	},
2354 	.def_cfg = &(struct s3c2410_uartcfg) {
2355 		.ucon		= S3C2410_UCON_DEFAULT,
2356 		.ufcon		= S3C2410_UFCON_DEFAULT,
2357 	},
2358 };
2359 #define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
2360 #else
2361 #define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2362 #endif
2363 
2364 #ifdef CONFIG_CPU_S5PV210
2365 static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2366 	.info = &(struct s3c24xx_uart_info) {
2367 		.name		= "Samsung S5PV210 UART",
2368 		.type		= PORT_S3C6400,
2369 		.has_divslot	= 1,
2370 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2371 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2372 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2373 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2374 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2375 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2376 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2377 		.num_clks	= 2,
2378 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2379 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2380 	},
2381 	.def_cfg = &(struct s3c2410_uartcfg) {
2382 		.ucon		= S5PV210_UCON_DEFAULT,
2383 		.ufcon		= S5PV210_UFCON_DEFAULT,
2384 	},
2385 	.fifosize = { 256, 64, 16, 16 },
2386 };
2387 #define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
2388 #else
2389 #define S5PV210_SERIAL_DRV_DATA	(kernel_ulong_t)NULL
2390 #endif
2391 
2392 #if defined(CONFIG_ARCH_EXYNOS)
2393 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2394 	.info = &(struct s3c24xx_uart_info) {			\
2395 		.name		= "Samsung Exynos UART",	\
2396 		.type		= PORT_S3C6400,			\
2397 		.has_divslot	= 1,				\
2398 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2399 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2400 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2401 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2402 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2403 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2404 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2405 		.num_clks	= 1,				\
2406 		.clksel_mask	= 0,				\
2407 		.clksel_shift	= 0,				\
2408 	},							\
2409 	.def_cfg = &(struct s3c2410_uartcfg) {			\
2410 		.ucon		= S5PV210_UCON_DEFAULT,		\
2411 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2412 		.has_fracval	= 1,				\
2413 	}							\
2414 
2415 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2416 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2417 	.fifosize = { 256, 64, 16, 16 },
2418 };
2419 
2420 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2421 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2422 	.fifosize = { 64, 256, 16, 256 },
2423 };
2424 
2425 #define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
2426 #define EXYNOS5433_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos5433_serial_drv_data)
2427 #else
2428 #define EXYNOS4210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2429 #define EXYNOS5433_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2430 #endif
2431 
2432 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2433 	{
2434 		.name		= "s3c2410-uart",
2435 		.driver_data	= S3C2410_SERIAL_DRV_DATA,
2436 	}, {
2437 		.name		= "s3c2412-uart",
2438 		.driver_data	= S3C2412_SERIAL_DRV_DATA,
2439 	}, {
2440 		.name		= "s3c2440-uart",
2441 		.driver_data	= S3C2440_SERIAL_DRV_DATA,
2442 	}, {
2443 		.name		= "s3c6400-uart",
2444 		.driver_data	= S3C6400_SERIAL_DRV_DATA,
2445 	}, {
2446 		.name		= "s5pv210-uart",
2447 		.driver_data	= S5PV210_SERIAL_DRV_DATA,
2448 	}, {
2449 		.name		= "exynos4210-uart",
2450 		.driver_data	= EXYNOS4210_SERIAL_DRV_DATA,
2451 	}, {
2452 		.name		= "exynos5433-uart",
2453 		.driver_data	= EXYNOS5433_SERIAL_DRV_DATA,
2454 	},
2455 	{ },
2456 };
2457 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2458 
2459 #ifdef CONFIG_OF
2460 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2461 	{ .compatible = "samsung,s3c2410-uart",
2462 		.data = (void *)S3C2410_SERIAL_DRV_DATA },
2463 	{ .compatible = "samsung,s3c2412-uart",
2464 		.data = (void *)S3C2412_SERIAL_DRV_DATA },
2465 	{ .compatible = "samsung,s3c2440-uart",
2466 		.data = (void *)S3C2440_SERIAL_DRV_DATA },
2467 	{ .compatible = "samsung,s3c6400-uart",
2468 		.data = (void *)S3C6400_SERIAL_DRV_DATA },
2469 	{ .compatible = "samsung,s5pv210-uart",
2470 		.data = (void *)S5PV210_SERIAL_DRV_DATA },
2471 	{ .compatible = "samsung,exynos4210-uart",
2472 		.data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
2473 	{ .compatible = "samsung,exynos5433-uart",
2474 		.data = (void *)EXYNOS5433_SERIAL_DRV_DATA },
2475 	{},
2476 };
2477 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2478 #endif
2479 
2480 static struct platform_driver samsung_serial_driver = {
2481 	.probe		= s3c24xx_serial_probe,
2482 	.remove		= s3c24xx_serial_remove,
2483 	.id_table	= s3c24xx_serial_driver_ids,
2484 	.driver		= {
2485 		.name	= "samsung-uart",
2486 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2487 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2488 	},
2489 };
2490 
2491 module_platform_driver(samsung_serial_driver);
2492 
2493 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2494 /*
2495  * Early console.
2496  */
2497 
2498 struct samsung_early_console_data {
2499 	u32 txfull_mask;
2500 };
2501 
2502 static void samsung_early_busyuart(struct uart_port *port)
2503 {
2504 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2505 		;
2506 }
2507 
2508 static void samsung_early_busyuart_fifo(struct uart_port *port)
2509 {
2510 	struct samsung_early_console_data *data = port->private_data;
2511 
2512 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2513 		;
2514 }
2515 
2516 static void samsung_early_putc(struct uart_port *port, int c)
2517 {
2518 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2519 		samsung_early_busyuart_fifo(port);
2520 	else
2521 		samsung_early_busyuart(port);
2522 
2523 	writeb(c, port->membase + S3C2410_UTXH);
2524 }
2525 
2526 static void samsung_early_write(struct console *con, const char *s, unsigned n)
2527 {
2528 	struct earlycon_device *dev = con->data;
2529 
2530 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2531 }
2532 
2533 static int __init samsung_early_console_setup(struct earlycon_device *device,
2534 					      const char *opt)
2535 {
2536 	if (!device->port.membase)
2537 		return -ENODEV;
2538 
2539 	device->con->write = samsung_early_write;
2540 	return 0;
2541 }
2542 
2543 /* S3C2410 */
2544 static struct samsung_early_console_data s3c2410_early_console_data = {
2545 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2546 };
2547 
2548 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
2549 					      const char *opt)
2550 {
2551 	device->port.private_data = &s3c2410_early_console_data;
2552 	return samsung_early_console_setup(device, opt);
2553 }
2554 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
2555 			s3c2410_early_console_setup);
2556 
2557 /* S3C2412, S3C2440, S3C64xx */
2558 static struct samsung_early_console_data s3c2440_early_console_data = {
2559 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2560 };
2561 
2562 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2563 					      const char *opt)
2564 {
2565 	device->port.private_data = &s3c2440_early_console_data;
2566 	return samsung_early_console_setup(device, opt);
2567 }
2568 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
2569 			s3c2440_early_console_setup);
2570 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
2571 			s3c2440_early_console_setup);
2572 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2573 			s3c2440_early_console_setup);
2574 
2575 /* S5PV210, EXYNOS */
2576 static struct samsung_early_console_data s5pv210_early_console_data = {
2577 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2578 };
2579 
2580 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2581 					      const char *opt)
2582 {
2583 	device->port.private_data = &s5pv210_early_console_data;
2584 	return samsung_early_console_setup(device, opt);
2585 }
2586 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2587 			s5pv210_early_console_setup);
2588 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2589 			s5pv210_early_console_setup);
2590 #endif
2591 
2592 MODULE_ALIAS("platform:samsung-uart");
2593 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2594 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2595 MODULE_LICENSE("GPL v2");
2596