xref: /linux/drivers/tty/serial/samsung_tty.c (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
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/console.h>
25 #include <linux/clk.h>
26 #include <linux/cpufreq.h>
27 #include <linux/delay.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/dmaengine.h>
30 #include <linux/init.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/math.h>
34 #include <linux/module.h>
35 #include <linux/of.h>
36 #include <linux/platform_device.h>
37 #include <linux/serial.h>
38 #include <linux/serial_core.h>
39 #include <linux/serial_s3c.h>
40 #include <linux/slab.h>
41 #include <linux/sysrq.h>
42 #include <linux/tty.h>
43 #include <linux/tty_flip.h>
44 #include <linux/types.h>
45 
46 #include <asm/irq.h>
47 
48 /* UART name and device definitions */
49 
50 #define S3C24XX_SERIAL_NAME	"ttySAC"
51 #define S3C24XX_SERIAL_MAJOR	204
52 #define S3C24XX_SERIAL_MINOR	64
53 
54 #ifdef CONFIG_ARM64
55 #define UART_NR			12
56 #else
57 #define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
58 #endif
59 
60 #define S3C24XX_TX_PIO			1
61 #define S3C24XX_TX_DMA			2
62 #define S3C24XX_RX_PIO			1
63 #define S3C24XX_RX_DMA			2
64 
65 /* flag to ignore all characters coming in */
66 #define RXSTAT_DUMMY_READ (0x10000000)
67 
68 enum s3c24xx_port_type {
69 	TYPE_S3C6400,
70 	TYPE_APPLE_S5L,
71 };
72 
73 struct s3c24xx_uart_info {
74 	const char		*name;
75 	enum s3c24xx_port_type	type;
76 	unsigned int		port_type;
77 	unsigned int		fifosize;
78 	u32			rx_fifomask;
79 	u32			rx_fifoshift;
80 	u32			rx_fifofull;
81 	u32			tx_fifomask;
82 	u32			tx_fifoshift;
83 	u32			tx_fifofull;
84 	u32			clksel_mask;
85 	u32			clksel_shift;
86 	u32			ucon_mask;
87 	u8			def_clk_sel;
88 	u8			num_clks;
89 	u8			iotype;
90 
91 	/* uart port features */
92 	bool			has_divslot;
93 };
94 
95 struct s3c24xx_serial_drv_data {
96 	const struct s3c24xx_uart_info	info;
97 	const struct s3c2410_uartcfg	def_cfg;
98 	const unsigned int		fifosize[UART_NR];
99 };
100 
101 struct s3c24xx_uart_dma {
102 	unsigned int			rx_chan_id;
103 	unsigned int			tx_chan_id;
104 
105 	struct dma_slave_config		rx_conf;
106 	struct dma_slave_config		tx_conf;
107 
108 	struct dma_chan			*rx_chan;
109 	struct dma_chan			*tx_chan;
110 
111 	dma_addr_t			rx_addr;
112 	dma_addr_t			tx_addr;
113 
114 	dma_cookie_t			rx_cookie;
115 	dma_cookie_t			tx_cookie;
116 
117 	char				*rx_buf;
118 
119 	dma_addr_t			tx_transfer_addr;
120 
121 	size_t				rx_size;
122 	size_t				tx_size;
123 
124 	struct dma_async_tx_descriptor	*tx_desc;
125 	struct dma_async_tx_descriptor	*rx_desc;
126 
127 	int				tx_bytes_requested;
128 	int				rx_bytes_requested;
129 };
130 
131 struct s3c24xx_uart_port {
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 				   u32 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 				     u32 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 bool 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 	int count = 10000;
248 	u32 ucon, ufcon;
249 
250 	uart_port_lock_irqsave(port, &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 	uart_port_unlock_irqrestore(port, 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 	u32 ucon;
272 
273 	uart_port_lock_irqsave(port, &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 	uart_port_unlock_irqrestore(port, 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 tty_port *tport = &port->state->port;
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 	uart_port_lock_irqsave(port, &flags);
347 
348 	uart_xmit_advance(port, count);
349 	ourport->tx_in_progress = 0;
350 
351 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
352 		uart_write_wakeup(port);
353 
354 	s3c24xx_serial_start_next_tx(ourport);
355 	uart_port_unlock_irqrestore(port, 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, unsigned int tail)
435 {
436 	struct s3c24xx_uart_dma *dma = ourport->dma;
437 
438 	if (ourport->tx_mode != S3C24XX_TX_DMA)
439 		enable_tx_dma(ourport);
440 
441 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
442 	dma->tx_transfer_addr = dma->tx_addr + tail;
443 
444 	dma_sync_single_for_device(dma->tx_chan->device->dev,
445 				   dma->tx_transfer_addr, dma->tx_size,
446 				   DMA_TO_DEVICE);
447 
448 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
449 				dma->tx_transfer_addr, dma->tx_size,
450 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
451 	if (!dma->tx_desc) {
452 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
453 		return -EIO;
454 	}
455 
456 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
457 	dma->tx_desc->callback_param = ourport;
458 	dma->tx_bytes_requested = dma->tx_size;
459 
460 	ourport->tx_in_progress = S3C24XX_TX_DMA;
461 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
462 	dma_async_issue_pending(dma->tx_chan);
463 	return 0;
464 }
465 
466 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
467 {
468 	struct uart_port *port = &ourport->port;
469 	struct tty_port *tport = &port->state->port;
470 	unsigned int count, tail;
471 
472 	/* Get data size up to the end of buffer */
473 	count = kfifo_out_linear(&tport->xmit_fifo, &tail, UART_XMIT_SIZE);
474 
475 	if (!count) {
476 		s3c24xx_serial_stop_tx(port);
477 		return;
478 	}
479 
480 	if (!ourport->dma || !ourport->dma->tx_chan ||
481 	    count < ourport->min_dma_size ||
482 	    tail & (dma_get_cache_alignment() - 1))
483 		s3c24xx_serial_start_tx_pio(ourport);
484 	else
485 		s3c24xx_serial_start_tx_dma(ourport, count, tail);
486 }
487 
488 static void s3c24xx_serial_start_tx(struct uart_port *port)
489 {
490 	struct s3c24xx_uart_port *ourport = to_ourport(port);
491 	struct tty_port *tport = &port->state->port;
492 
493 	if (!ourport->tx_enabled) {
494 		if (port->flags & UPF_CONS_FLOW)
495 			s3c24xx_serial_rx_disable(port);
496 
497 		ourport->tx_enabled = 1;
498 		if (!ourport->dma || !ourport->dma->tx_chan)
499 			s3c24xx_serial_start_tx_pio(ourport);
500 	}
501 
502 	if (ourport->dma && ourport->dma->tx_chan) {
503 		if (!kfifo_is_empty(&tport->xmit_fifo) &&
504 				!ourport->tx_in_progress)
505 			s3c24xx_serial_start_next_tx(ourport);
506 	}
507 }
508 
509 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
510 		struct tty_port *tty, int count)
511 {
512 	struct s3c24xx_uart_dma *dma = ourport->dma;
513 	int copied;
514 
515 	if (!count)
516 		return;
517 
518 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
519 				dma->rx_size, DMA_FROM_DEVICE);
520 
521 	ourport->port.icount.rx += count;
522 	if (!tty) {
523 		dev_err(ourport->port.dev, "No tty port\n");
524 		return;
525 	}
526 	copied = tty_insert_flip_string(tty,
527 			((unsigned char *)(ourport->dma->rx_buf)), count);
528 	if (copied != count) {
529 		WARN_ON(1);
530 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
531 	}
532 }
533 
534 static void s3c24xx_serial_stop_rx(struct uart_port *port)
535 {
536 	struct s3c24xx_uart_port *ourport = to_ourport(port);
537 	struct s3c24xx_uart_dma *dma = ourport->dma;
538 	struct tty_port *t = &port->state->port;
539 	struct dma_tx_state state;
540 	enum dma_status dma_status;
541 	unsigned int received;
542 
543 	if (ourport->rx_enabled) {
544 		dev_dbg(port->dev, "stopping rx\n");
545 		switch (ourport->info->type) {
546 		case TYPE_S3C6400:
547 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
548 					S3C64XX_UINTM);
549 			break;
550 		case TYPE_APPLE_S5L:
551 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
552 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
553 			break;
554 		default:
555 			disable_irq_nosync(ourport->rx_irq);
556 			break;
557 		}
558 		ourport->rx_enabled = 0;
559 	}
560 	if (dma && dma->rx_chan) {
561 		dmaengine_pause(dma->tx_chan);
562 		dma_status = dmaengine_tx_status(dma->rx_chan,
563 				dma->rx_cookie, &state);
564 		if (dma_status == DMA_IN_PROGRESS ||
565 			dma_status == DMA_PAUSED) {
566 			received = dma->rx_bytes_requested - state.residue;
567 			dmaengine_terminate_all(dma->rx_chan);
568 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
569 		}
570 	}
571 }
572 
573 static inline const struct s3c24xx_uart_info
574 	*s3c24xx_port_to_info(struct uart_port *port)
575 {
576 	return to_ourport(port)->info;
577 }
578 
579 static inline const struct s3c2410_uartcfg
580 	*s3c24xx_port_to_cfg(const struct uart_port *port)
581 {
582 	const struct s3c24xx_uart_port *ourport;
583 
584 	if (port->dev == NULL)
585 		return NULL;
586 
587 	ourport = container_of(port, struct s3c24xx_uart_port, port);
588 	return ourport->cfg;
589 }
590 
591 static unsigned int
592 s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport, u32 ufstat)
593 {
594 	const struct s3c24xx_uart_info *info = ourport->info;
595 
596 	if (ufstat & info->rx_fifofull)
597 		return ourport->port.fifosize;
598 
599 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
600 }
601 
602 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
603 static void s3c24xx_serial_rx_dma_complete(void *args)
604 {
605 	struct s3c24xx_uart_port *ourport = args;
606 	struct uart_port *port = &ourport->port;
607 
608 	struct s3c24xx_uart_dma *dma = ourport->dma;
609 	struct tty_port *t = &port->state->port;
610 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
611 
612 	struct dma_tx_state state;
613 	unsigned long flags;
614 	int received;
615 
616 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
617 	received  = dma->rx_bytes_requested - state.residue;
618 	async_tx_ack(dma->rx_desc);
619 
620 	uart_port_lock_irqsave(port, &flags);
621 
622 	if (received)
623 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
624 
625 	if (tty) {
626 		tty_flip_buffer_push(t);
627 		tty_kref_put(tty);
628 	}
629 
630 	s3c64xx_start_rx_dma(ourport);
631 
632 	uart_port_unlock_irqrestore(port, flags);
633 }
634 
635 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
636 {
637 	struct s3c24xx_uart_dma *dma = ourport->dma;
638 
639 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
640 				   dma->rx_size, DMA_FROM_DEVICE);
641 
642 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
643 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
644 				DMA_PREP_INTERRUPT);
645 	if (!dma->rx_desc) {
646 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
647 		return;
648 	}
649 
650 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
651 	dma->rx_desc->callback_param = ourport;
652 	dma->rx_bytes_requested = dma->rx_size;
653 
654 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
655 	dma_async_issue_pending(dma->rx_chan);
656 }
657 
658 /* ? - where has parity gone?? */
659 #define S3C2410_UERSTAT_PARITY (0x1000)
660 
661 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
662 {
663 	struct uart_port *port = &ourport->port;
664 	u32 ucon;
665 
666 	/* set Rx mode to DMA mode */
667 	ucon = rd_regl(port, S3C2410_UCON);
668 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
669 			S3C64XX_UCON_TIMEOUT_MASK |
670 			S3C64XX_UCON_EMPTYINT_EN |
671 			S3C64XX_UCON_DMASUS_EN |
672 			S3C64XX_UCON_TIMEOUT_EN |
673 			S3C64XX_UCON_RXMODE_MASK);
674 	ucon |= S3C64XX_UCON_RXBURST_1 |
675 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
676 			S3C64XX_UCON_EMPTYINT_EN |
677 			S3C64XX_UCON_TIMEOUT_EN |
678 			S3C64XX_UCON_RXMODE_DMA;
679 	wr_regl(port, S3C2410_UCON, ucon);
680 
681 	ourport->rx_mode = S3C24XX_RX_DMA;
682 }
683 
684 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
685 {
686 	struct uart_port *port = &ourport->port;
687 	u32 ucon;
688 
689 	/* set Rx mode to DMA mode */
690 	ucon = rd_regl(port, S3C2410_UCON);
691 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
692 	ucon |= S3C64XX_UCON_RXMODE_CPU;
693 
694 	/* Apple types use these bits for IRQ masks */
695 	if (ourport->info->type != TYPE_APPLE_S5L) {
696 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
697 				S3C64XX_UCON_EMPTYINT_EN |
698 				S3C64XX_UCON_DMASUS_EN |
699 				S3C64XX_UCON_TIMEOUT_EN);
700 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
701 				S3C64XX_UCON_TIMEOUT_EN;
702 	}
703 	wr_regl(port, S3C2410_UCON, ucon);
704 
705 	ourport->rx_mode = S3C24XX_RX_PIO;
706 }
707 
708 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
709 
710 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
711 {
712 	struct s3c24xx_uart_port *ourport = dev_id;
713 	struct uart_port *port = &ourport->port;
714 	struct s3c24xx_uart_dma *dma = ourport->dma;
715 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
716 	struct tty_port *t = &port->state->port;
717 	struct dma_tx_state state;
718 	unsigned int received;
719 	u32 utrstat;
720 
721 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
722 	rd_regl(port, S3C2410_UFSTAT);
723 
724 	uart_port_lock(port);
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 	uart_port_unlock(port);
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 max_count = port->fifosize;
762 	unsigned int fifocnt = 0;
763 	u32 ufcon, ufstat, uerstat;
764 	u8 ch, flag;
765 
766 	while (max_count-- > 0) {
767 		/*
768 		 * Receive all characters known to be in FIFO
769 		 * before reading FIFO level again
770 		 */
771 		if (fifocnt == 0) {
772 			ufstat = rd_regl(port, S3C2410_UFSTAT);
773 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
774 			if (fifocnt == 0)
775 				break;
776 		}
777 		fifocnt--;
778 
779 		uerstat = rd_regl(port, S3C2410_UERSTAT);
780 		ch = rd_reg(port, S3C2410_URXH);
781 
782 		if (port->flags & UPF_CONS_FLOW) {
783 			bool txe = s3c24xx_serial_txempty_nofifo(port);
784 
785 			if (ourport->rx_enabled) {
786 				if (!txe) {
787 					ourport->rx_enabled = 0;
788 					continue;
789 				}
790 			} else {
791 				if (txe) {
792 					ufcon = rd_regl(port, S3C2410_UFCON);
793 					ufcon |= S3C2410_UFCON_RESETRX;
794 					wr_regl(port, S3C2410_UFCON, ufcon);
795 					ourport->rx_enabled = 1;
796 					return;
797 				}
798 				continue;
799 			}
800 		}
801 
802 		/* insert the character into the buffer */
803 
804 		flag = TTY_NORMAL;
805 		port->icount.rx++;
806 
807 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
808 			dev_dbg(port->dev,
809 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
810 				ch, uerstat);
811 
812 			/* check for break */
813 			if (uerstat & S3C2410_UERSTAT_BREAK) {
814 				dev_dbg(port->dev, "break!\n");
815 				port->icount.brk++;
816 				if (uart_handle_break(port))
817 					continue; /* Ignore character */
818 			}
819 
820 			if (uerstat & S3C2410_UERSTAT_FRAME)
821 				port->icount.frame++;
822 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
823 				port->icount.overrun++;
824 
825 			uerstat &= port->read_status_mask;
826 
827 			if (uerstat & S3C2410_UERSTAT_BREAK)
828 				flag = TTY_BREAK;
829 			else if (uerstat & S3C2410_UERSTAT_PARITY)
830 				flag = TTY_PARITY;
831 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
832 					    S3C2410_UERSTAT_OVERRUN))
833 				flag = TTY_FRAME;
834 		}
835 
836 		if (uart_handle_sysrq_char(port, ch))
837 			continue; /* Ignore character */
838 
839 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
840 				 ch, flag);
841 	}
842 
843 	tty_flip_buffer_push(&port->state->port);
844 }
845 
846 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
847 {
848 	struct s3c24xx_uart_port *ourport = dev_id;
849 	struct uart_port *port = &ourport->port;
850 
851 	uart_port_lock(port);
852 	s3c24xx_serial_rx_drain_fifo(ourport);
853 	uart_port_unlock(port);
854 
855 	return IRQ_HANDLED;
856 }
857 
858 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
859 {
860 	struct s3c24xx_uart_port *ourport = dev_id;
861 
862 	if (ourport->dma && ourport->dma->rx_chan)
863 		return s3c24xx_serial_rx_chars_dma(dev_id);
864 	return s3c24xx_serial_rx_chars_pio(dev_id);
865 }
866 
867 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
868 {
869 	struct uart_port *port = &ourport->port;
870 	struct tty_port *tport = &port->state->port;
871 	unsigned int count, dma_count = 0, tail;
872 
873 	count = kfifo_out_linear(&tport->xmit_fifo, &tail, UART_XMIT_SIZE);
874 
875 	if (ourport->dma && ourport->dma->tx_chan &&
876 	    count >= ourport->min_dma_size) {
877 		int align = dma_get_cache_alignment() -
878 			(tail & (dma_get_cache_alignment() - 1));
879 		if (count - align >= ourport->min_dma_size) {
880 			dma_count = count - align;
881 			count = align;
882 			tail += align;
883 		}
884 	}
885 
886 	if (port->x_char) {
887 		wr_reg(port, S3C2410_UTXH, port->x_char);
888 		port->icount.tx++;
889 		port->x_char = 0;
890 		return;
891 	}
892 
893 	/* if there isn't anything more to transmit, or the uart is now
894 	 * stopped, disable the uart and exit
895 	 */
896 
897 	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
898 		s3c24xx_serial_stop_tx(port);
899 		return;
900 	}
901 
902 	/* try and drain the buffer... */
903 
904 	if (count > port->fifosize) {
905 		count = port->fifosize;
906 		dma_count = 0;
907 	}
908 
909 	while (!(rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)) {
910 		unsigned char ch;
911 
912 		if (!uart_fifo_get(port, &ch))
913 			break;
914 
915 		wr_reg(port, S3C2410_UTXH, ch);
916 		count--;
917 	}
918 
919 	if (!count && dma_count) {
920 		s3c24xx_serial_start_tx_dma(ourport, dma_count, tail);
921 		return;
922 	}
923 
924 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
925 		uart_write_wakeup(port);
926 
927 	if (kfifo_is_empty(&tport->xmit_fifo))
928 		s3c24xx_serial_stop_tx(port);
929 }
930 
931 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
932 {
933 	struct s3c24xx_uart_port *ourport = id;
934 	struct uart_port *port = &ourport->port;
935 
936 	uart_port_lock(port);
937 
938 	s3c24xx_serial_tx_chars(ourport);
939 
940 	uart_port_unlock(port);
941 	return IRQ_HANDLED;
942 }
943 
944 /* interrupt handler for s3c64xx and later SoC's.*/
945 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
946 {
947 	const struct s3c24xx_uart_port *ourport = id;
948 	const struct uart_port *port = &ourport->port;
949 	u32 pend = rd_regl(port, S3C64XX_UINTP);
950 	irqreturn_t ret = IRQ_HANDLED;
951 
952 	if (pend & S3C64XX_UINTM_RXD_MSK) {
953 		ret = s3c24xx_serial_rx_irq(irq, id);
954 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
955 	}
956 	if (pend & S3C64XX_UINTM_TXD_MSK) {
957 		ret = s3c24xx_serial_tx_irq(irq, id);
958 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
959 	}
960 	return ret;
961 }
962 
963 /* interrupt handler for Apple SoC's.*/
964 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
965 {
966 	const struct s3c24xx_uart_port *ourport = id;
967 	const struct uart_port *port = &ourport->port;
968 	u32 pend = rd_regl(port, S3C2410_UTRSTAT);
969 	irqreturn_t ret = IRQ_NONE;
970 
971 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
972 		wr_regl(port, S3C2410_UTRSTAT,
973 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
974 		ret = s3c24xx_serial_rx_irq(irq, id);
975 	}
976 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
977 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
978 		ret = s3c24xx_serial_tx_irq(irq, id);
979 	}
980 
981 	return ret;
982 }
983 
984 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
985 {
986 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
987 	u32 ufstat = rd_regl(port, S3C2410_UFSTAT);
988 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
989 
990 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
991 		if ((ufstat & info->tx_fifomask) ||
992 		    (ufstat & info->tx_fifofull))
993 			return 0;
994 		return TIOCSER_TEMT;
995 	}
996 
997 	return s3c24xx_serial_txempty_nofifo(port) ? TIOCSER_TEMT : 0;
998 }
999 
1000 /* no modem control lines */
1001 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1002 {
1003 	u32 umstat = rd_reg(port, S3C2410_UMSTAT);
1004 
1005 	if (umstat & S3C2410_UMSTAT_CTS)
1006 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1007 	else
1008 		return TIOCM_CAR | TIOCM_DSR;
1009 }
1010 
1011 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1012 {
1013 	u32 umcon = rd_regl(port, S3C2410_UMCON);
1014 	u32 ucon = rd_regl(port, S3C2410_UCON);
1015 
1016 	if (mctrl & TIOCM_RTS)
1017 		umcon |= S3C2410_UMCOM_RTS_LOW;
1018 	else
1019 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1020 
1021 	wr_regl(port, S3C2410_UMCON, umcon);
1022 
1023 	if (mctrl & TIOCM_LOOP)
1024 		ucon |= S3C2410_UCON_LOOPBACK;
1025 	else
1026 		ucon &= ~S3C2410_UCON_LOOPBACK;
1027 
1028 	wr_regl(port, S3C2410_UCON, ucon);
1029 }
1030 
1031 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1032 {
1033 	unsigned long flags;
1034 	u32 ucon;
1035 
1036 	uart_port_lock_irqsave(port, &flags);
1037 
1038 	ucon = rd_regl(port, S3C2410_UCON);
1039 
1040 	if (break_state)
1041 		ucon |= S3C2410_UCON_SBREAK;
1042 	else
1043 		ucon &= ~S3C2410_UCON_SBREAK;
1044 
1045 	wr_regl(port, S3C2410_UCON, ucon);
1046 
1047 	uart_port_unlock_irqrestore(port, flags);
1048 }
1049 
1050 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1051 {
1052 	struct s3c24xx_uart_dma	*dma = p->dma;
1053 	struct dma_slave_caps dma_caps;
1054 	const char *reason = NULL;
1055 	int ret;
1056 
1057 	/* Default slave configuration parameters */
1058 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1059 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1060 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1061 	dma->rx_conf.src_maxburst	= 1;
1062 
1063 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1064 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1065 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1066 	dma->tx_conf.dst_maxburst	= 1;
1067 
1068 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1069 
1070 	if (IS_ERR(dma->rx_chan)) {
1071 		reason = "DMA RX channel request failed";
1072 		ret = PTR_ERR(dma->rx_chan);
1073 		goto err_warn;
1074 	}
1075 
1076 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1077 	if (ret < 0 ||
1078 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1079 		reason = "insufficient DMA RX engine capabilities";
1080 		ret = -EOPNOTSUPP;
1081 		goto err_release_rx;
1082 	}
1083 
1084 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1085 
1086 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1087 	if (IS_ERR(dma->tx_chan)) {
1088 		reason = "DMA TX channel request failed";
1089 		ret = PTR_ERR(dma->tx_chan);
1090 		goto err_release_rx;
1091 	}
1092 
1093 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1094 	if (ret < 0 ||
1095 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1096 		reason = "insufficient DMA TX engine capabilities";
1097 		ret = -EOPNOTSUPP;
1098 		goto err_release_tx;
1099 	}
1100 
1101 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1102 
1103 	/* RX buffer */
1104 	dma->rx_size = PAGE_SIZE;
1105 
1106 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1107 	if (!dma->rx_buf) {
1108 		ret = -ENOMEM;
1109 		goto err_release_tx;
1110 	}
1111 
1112 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1113 				      dma->rx_size, DMA_FROM_DEVICE);
1114 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1115 		reason = "DMA mapping error for RX buffer";
1116 		ret = -EIO;
1117 		goto err_free_rx;
1118 	}
1119 
1120 	/* TX buffer */
1121 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1122 				      p->port.state->port.xmit_buf,
1123 				      UART_XMIT_SIZE,
1124 				      DMA_TO_DEVICE);
1125 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1126 		reason = "DMA mapping error for TX buffer";
1127 		ret = -EIO;
1128 		goto err_unmap_rx;
1129 	}
1130 
1131 	return 0;
1132 
1133 err_unmap_rx:
1134 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1135 			 dma->rx_size, DMA_FROM_DEVICE);
1136 err_free_rx:
1137 	kfree(dma->rx_buf);
1138 err_release_tx:
1139 	dma_release_channel(dma->tx_chan);
1140 err_release_rx:
1141 	dma_release_channel(dma->rx_chan);
1142 err_warn:
1143 	if (reason)
1144 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1145 	return ret;
1146 }
1147 
1148 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1149 {
1150 	struct s3c24xx_uart_dma	*dma = p->dma;
1151 
1152 	if (dma->rx_chan) {
1153 		dmaengine_terminate_all(dma->rx_chan);
1154 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1155 				 dma->rx_size, DMA_FROM_DEVICE);
1156 		kfree(dma->rx_buf);
1157 		dma_release_channel(dma->rx_chan);
1158 		dma->rx_chan = NULL;
1159 	}
1160 
1161 	if (dma->tx_chan) {
1162 		dmaengine_terminate_all(dma->tx_chan);
1163 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1164 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1165 		dma_release_channel(dma->tx_chan);
1166 		dma->tx_chan = NULL;
1167 	}
1168 }
1169 
1170 static void s3c64xx_serial_shutdown(struct uart_port *port)
1171 {
1172 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1173 
1174 	ourport->tx_enabled = 0;
1175 	ourport->tx_mode = 0;
1176 	ourport->rx_enabled = 0;
1177 
1178 	free_irq(port->irq, ourport);
1179 
1180 	wr_regl(port, S3C64XX_UINTP, 0xf);
1181 	wr_regl(port, S3C64XX_UINTM, 0xf);
1182 
1183 	if (ourport->dma)
1184 		s3c24xx_serial_release_dma(ourport);
1185 
1186 	ourport->tx_in_progress = 0;
1187 }
1188 
1189 static void apple_s5l_serial_shutdown(struct uart_port *port)
1190 {
1191 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1192 
1193 	u32 ucon;
1194 
1195 	ucon = rd_regl(port, S3C2410_UCON);
1196 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1197 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1198 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1199 	wr_regl(port, S3C2410_UCON, ucon);
1200 
1201 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1202 
1203 	free_irq(port->irq, ourport);
1204 
1205 	ourport->tx_enabled = 0;
1206 	ourport->tx_mode = 0;
1207 	ourport->rx_enabled = 0;
1208 
1209 	if (ourport->dma)
1210 		s3c24xx_serial_release_dma(ourport);
1211 
1212 	ourport->tx_in_progress = 0;
1213 }
1214 
1215 static int s3c64xx_serial_startup(struct uart_port *port)
1216 {
1217 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1218 	unsigned long flags;
1219 	u32 ufcon;
1220 	int ret;
1221 
1222 	wr_regl(port, S3C64XX_UINTM, 0xf);
1223 	if (ourport->dma) {
1224 		ret = s3c24xx_serial_request_dma(ourport);
1225 		if (ret < 0) {
1226 			devm_kfree(port->dev, ourport->dma);
1227 			ourport->dma = NULL;
1228 		}
1229 	}
1230 
1231 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1232 			  s3c24xx_serial_portname(port), ourport);
1233 	if (ret) {
1234 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1235 		return ret;
1236 	}
1237 
1238 	/* For compatibility with s3c24xx Soc's */
1239 	ourport->rx_enabled = 1;
1240 	ourport->tx_enabled = 0;
1241 
1242 	uart_port_lock_irqsave(port, &flags);
1243 
1244 	ufcon = rd_regl(port, S3C2410_UFCON);
1245 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1246 	if (!uart_console(port))
1247 		ufcon |= S3C2410_UFCON_RESETTX;
1248 	wr_regl(port, S3C2410_UFCON, ufcon);
1249 
1250 	enable_rx_pio(ourport);
1251 
1252 	uart_port_unlock_irqrestore(port, flags);
1253 
1254 	/* Enable Rx Interrupt */
1255 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1256 
1257 	return ret;
1258 }
1259 
1260 static int apple_s5l_serial_startup(struct uart_port *port)
1261 {
1262 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1263 	unsigned long flags;
1264 	u32 ufcon;
1265 	int ret;
1266 
1267 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1268 
1269 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1270 			  s3c24xx_serial_portname(port), ourport);
1271 	if (ret) {
1272 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1273 		return ret;
1274 	}
1275 
1276 	/* For compatibility with s3c24xx Soc's */
1277 	ourport->rx_enabled = 1;
1278 	ourport->tx_enabled = 0;
1279 
1280 	uart_port_lock_irqsave(port, &flags);
1281 
1282 	ufcon = rd_regl(port, S3C2410_UFCON);
1283 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1284 	if (!uart_console(port))
1285 		ufcon |= S3C2410_UFCON_RESETTX;
1286 	wr_regl(port, S3C2410_UFCON, ufcon);
1287 
1288 	enable_rx_pio(ourport);
1289 
1290 	uart_port_unlock_irqrestore(port, flags);
1291 
1292 	/* Enable Rx Interrupt */
1293 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1294 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1295 
1296 	return ret;
1297 }
1298 
1299 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1300 			      unsigned int old)
1301 {
1302 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1303 	int timeout = 10000;
1304 
1305 	ourport->pm_level = level;
1306 
1307 	switch (level) {
1308 	case 3:
1309 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1310 			udelay(100);
1311 
1312 		if (!IS_ERR(ourport->baudclk))
1313 			clk_disable_unprepare(ourport->baudclk);
1314 
1315 		clk_disable_unprepare(ourport->clk);
1316 		break;
1317 
1318 	case 0:
1319 		clk_prepare_enable(ourport->clk);
1320 
1321 		if (!IS_ERR(ourport->baudclk))
1322 			clk_prepare_enable(ourport->baudclk);
1323 		break;
1324 	default:
1325 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1326 	}
1327 }
1328 
1329 /* baud rate calculation
1330  *
1331  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1332  * of different sources, including the peripheral clock ("pclk") and an
1333  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1334  * with a programmable extra divisor.
1335  *
1336  * The following code goes through the clock sources, and calculates the
1337  * baud clocks (and the resultant actual baud rates) and then tries to
1338  * pick the closest one and select that.
1339  *
1340  */
1341 
1342 #define MAX_CLK_NAME_LENGTH 15
1343 
1344 static inline u8 s3c24xx_serial_getsource(struct uart_port *port)
1345 {
1346 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1347 	u32 ucon;
1348 
1349 	if (info->num_clks == 1)
1350 		return 0;
1351 
1352 	ucon = rd_regl(port, S3C2410_UCON);
1353 	ucon &= info->clksel_mask;
1354 	return ucon >> info->clksel_shift;
1355 }
1356 
1357 static void s3c24xx_serial_setsource(struct uart_port *port, u8 clk_sel)
1358 {
1359 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1360 	u32 ucon;
1361 
1362 	if (info->num_clks == 1)
1363 		return;
1364 
1365 	ucon = rd_regl(port, S3C2410_UCON);
1366 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1367 		return;
1368 
1369 	ucon &= ~info->clksel_mask;
1370 	ucon |= clk_sel << info->clksel_shift;
1371 	wr_regl(port, S3C2410_UCON, ucon);
1372 }
1373 
1374 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1375 			unsigned int req_baud, struct clk **best_clk,
1376 			u8 *clk_num)
1377 {
1378 	const struct s3c24xx_uart_info *info = ourport->info;
1379 	struct clk *clk;
1380 	unsigned long rate;
1381 	unsigned int baud, quot, best_quot = 0;
1382 	char clkname[MAX_CLK_NAME_LENGTH];
1383 	int calc_deviation, deviation = (1 << 30) - 1;
1384 	u8 cnt;
1385 
1386 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1387 		/* Keep selected clock if provided */
1388 		if (ourport->cfg->clk_sel &&
1389 			!(ourport->cfg->clk_sel & (1 << cnt)))
1390 			continue;
1391 
1392 		sprintf(clkname, "clk_uart_baud%d", cnt);
1393 		clk = clk_get(ourport->port.dev, clkname);
1394 		if (IS_ERR(clk))
1395 			continue;
1396 
1397 		rate = clk_get_rate(clk);
1398 		if (!rate) {
1399 			dev_err(ourport->port.dev,
1400 				"Failed to get clock rate for %s.\n", clkname);
1401 			clk_put(clk);
1402 			continue;
1403 		}
1404 
1405 		if (ourport->info->has_divslot) {
1406 			unsigned long div = rate / req_baud;
1407 
1408 			/* The UDIVSLOT register on the newer UARTs allows us to
1409 			 * get a divisor adjustment of 1/16th on the baud clock.
1410 			 *
1411 			 * We don't keep the UDIVSLOT value (the 16ths we
1412 			 * calculated by not multiplying the baud by 16) as it
1413 			 * is easy enough to recalculate.
1414 			 */
1415 
1416 			quot = div / 16;
1417 			baud = rate / div;
1418 		} else {
1419 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1420 			baud = rate / (quot * 16);
1421 		}
1422 		quot--;
1423 
1424 		calc_deviation = abs(req_baud - baud);
1425 
1426 		if (calc_deviation < deviation) {
1427 			/*
1428 			 * If we find a better clk, release the previous one, if
1429 			 * any.
1430 			 */
1431 			if (!IS_ERR(*best_clk))
1432 				clk_put(*best_clk);
1433 			*best_clk = clk;
1434 			best_quot = quot;
1435 			*clk_num = cnt;
1436 			deviation = calc_deviation;
1437 		} else {
1438 			clk_put(clk);
1439 		}
1440 	}
1441 
1442 	return best_quot;
1443 }
1444 
1445 /* udivslot_table[]
1446  *
1447  * This table takes the fractional value of the baud divisor and gives
1448  * the recommended setting for the UDIVSLOT register.
1449  */
1450 static const u16 udivslot_table[16] = {
1451 	[0] = 0x0000,
1452 	[1] = 0x0080,
1453 	[2] = 0x0808,
1454 	[3] = 0x0888,
1455 	[4] = 0x2222,
1456 	[5] = 0x4924,
1457 	[6] = 0x4A52,
1458 	[7] = 0x54AA,
1459 	[8] = 0x5555,
1460 	[9] = 0xD555,
1461 	[10] = 0xD5D5,
1462 	[11] = 0xDDD5,
1463 	[12] = 0xDDDD,
1464 	[13] = 0xDFDD,
1465 	[14] = 0xDFDF,
1466 	[15] = 0xFFDF,
1467 };
1468 
1469 static void s3c24xx_serial_set_termios(struct uart_port *port,
1470 				       struct ktermios *termios,
1471 				       const struct ktermios *old)
1472 {
1473 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1474 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1475 	struct clk *clk = ERR_PTR(-EINVAL);
1476 	unsigned long flags;
1477 	unsigned int baud, quot;
1478 	unsigned int udivslot = 0;
1479 	u32 ulcon, umcon;
1480 	u8 clk_sel = 0;
1481 
1482 	/*
1483 	 * We don't support modem control lines.
1484 	 */
1485 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1486 	termios->c_cflag |= CLOCAL;
1487 
1488 	/*
1489 	 * Ask the core to calculate the divisor for us.
1490 	 */
1491 
1492 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1493 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1494 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1495 		quot = port->custom_divisor;
1496 	if (IS_ERR(clk))
1497 		return;
1498 
1499 	/* check to see if we need  to change clock source */
1500 
1501 	if (ourport->baudclk != clk) {
1502 		clk_prepare_enable(clk);
1503 
1504 		s3c24xx_serial_setsource(port, clk_sel);
1505 
1506 		if (!IS_ERR(ourport->baudclk)) {
1507 			clk_disable_unprepare(ourport->baudclk);
1508 			ourport->baudclk = ERR_PTR(-EINVAL);
1509 		}
1510 
1511 		ourport->baudclk = clk;
1512 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1513 	}
1514 
1515 	if (ourport->info->has_divslot) {
1516 		unsigned int div = ourport->baudclk_rate / baud;
1517 
1518 		if (cfg->has_fracval) {
1519 			udivslot = (div & 15);
1520 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1521 		} else {
1522 			udivslot = udivslot_table[div & 15];
1523 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1524 				udivslot, div & 15);
1525 		}
1526 	}
1527 
1528 	switch (termios->c_cflag & CSIZE) {
1529 	case CS5:
1530 		dev_dbg(port->dev, "config: 5bits/char\n");
1531 		ulcon = S3C2410_LCON_CS5;
1532 		break;
1533 	case CS6:
1534 		dev_dbg(port->dev, "config: 6bits/char\n");
1535 		ulcon = S3C2410_LCON_CS6;
1536 		break;
1537 	case CS7:
1538 		dev_dbg(port->dev, "config: 7bits/char\n");
1539 		ulcon = S3C2410_LCON_CS7;
1540 		break;
1541 	case CS8:
1542 	default:
1543 		dev_dbg(port->dev, "config: 8bits/char\n");
1544 		ulcon = S3C2410_LCON_CS8;
1545 		break;
1546 	}
1547 
1548 	/* preserve original lcon IR settings */
1549 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1550 
1551 	if (termios->c_cflag & CSTOPB)
1552 		ulcon |= S3C2410_LCON_STOPB;
1553 
1554 	if (termios->c_cflag & PARENB) {
1555 		if (termios->c_cflag & PARODD)
1556 			ulcon |= S3C2410_LCON_PODD;
1557 		else
1558 			ulcon |= S3C2410_LCON_PEVEN;
1559 	} else {
1560 		ulcon |= S3C2410_LCON_PNONE;
1561 	}
1562 
1563 	uart_port_lock_irqsave(port, &flags);
1564 
1565 	dev_dbg(port->dev,
1566 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1567 		ulcon, quot, udivslot);
1568 
1569 	wr_regl(port, S3C2410_ULCON, ulcon);
1570 	wr_regl(port, S3C2410_UBRDIV, quot);
1571 
1572 	port->status &= ~UPSTAT_AUTOCTS;
1573 
1574 	umcon = rd_regl(port, S3C2410_UMCON);
1575 	if (termios->c_cflag & CRTSCTS) {
1576 		umcon |= S3C2410_UMCOM_AFC;
1577 		/* Disable RTS when RX FIFO contains 63 bytes */
1578 		umcon &= ~S3C2412_UMCON_AFC_8;
1579 		port->status = UPSTAT_AUTOCTS;
1580 	} else {
1581 		umcon &= ~S3C2410_UMCOM_AFC;
1582 	}
1583 	wr_regl(port, S3C2410_UMCON, umcon);
1584 
1585 	if (ourport->info->has_divslot)
1586 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1587 
1588 	dev_dbg(port->dev,
1589 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1590 		rd_regl(port, S3C2410_ULCON),
1591 		rd_regl(port, S3C2410_UCON),
1592 		rd_regl(port, S3C2410_UFCON));
1593 
1594 	/*
1595 	 * Update the per-port timeout.
1596 	 */
1597 	uart_update_timeout(port, termios->c_cflag, baud);
1598 
1599 	/*
1600 	 * Which character status flags are we interested in?
1601 	 */
1602 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1603 	if (termios->c_iflag & INPCK)
1604 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1605 			S3C2410_UERSTAT_PARITY;
1606 	/*
1607 	 * Which character status flags should we ignore?
1608 	 */
1609 	port->ignore_status_mask = 0;
1610 	if (termios->c_iflag & IGNPAR)
1611 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1612 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1613 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1614 
1615 	/*
1616 	 * Ignore all characters if CREAD is not set.
1617 	 */
1618 	if ((termios->c_cflag & CREAD) == 0)
1619 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1620 
1621 	uart_port_unlock_irqrestore(port, flags);
1622 }
1623 
1624 static const char *s3c24xx_serial_type(struct uart_port *port)
1625 {
1626 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
1627 
1628 	switch (ourport->info->type) {
1629 	case TYPE_S3C6400:
1630 		return "S3C6400/10";
1631 	case TYPE_APPLE_S5L:
1632 		return "APPLE S5L";
1633 	default:
1634 		return NULL;
1635 	}
1636 }
1637 
1638 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1639 {
1640 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1641 
1642 	if (flags & UART_CONFIG_TYPE)
1643 		port->type = info->port_type;
1644 }
1645 
1646 /*
1647  * verify the new serial_struct (for TIOCSSERIAL).
1648  */
1649 static int
1650 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1651 {
1652 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1653 
1654 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1655 		return -EINVAL;
1656 
1657 	return 0;
1658 }
1659 
1660 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1661 
1662 static struct console s3c24xx_serial_console;
1663 
1664 static void __init s3c24xx_serial_register_console(void)
1665 {
1666 	register_console(&s3c24xx_serial_console);
1667 }
1668 
1669 static void s3c24xx_serial_unregister_console(void)
1670 {
1671 	if (console_is_registered(&s3c24xx_serial_console))
1672 		unregister_console(&s3c24xx_serial_console);
1673 }
1674 
1675 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1676 #else
1677 static inline void s3c24xx_serial_register_console(void) { }
1678 static inline void s3c24xx_serial_unregister_console(void) { }
1679 #define S3C24XX_SERIAL_CONSOLE NULL
1680 #endif
1681 
1682 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1683 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1684 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1685 			 unsigned char c);
1686 #endif
1687 
1688 static const struct uart_ops s3c64xx_serial_ops = {
1689 	.pm		= s3c24xx_serial_pm,
1690 	.tx_empty	= s3c24xx_serial_tx_empty,
1691 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1692 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1693 	.stop_tx	= s3c24xx_serial_stop_tx,
1694 	.start_tx	= s3c24xx_serial_start_tx,
1695 	.stop_rx	= s3c24xx_serial_stop_rx,
1696 	.break_ctl	= s3c24xx_serial_break_ctl,
1697 	.startup	= s3c64xx_serial_startup,
1698 	.shutdown	= s3c64xx_serial_shutdown,
1699 	.set_termios	= s3c24xx_serial_set_termios,
1700 	.type		= s3c24xx_serial_type,
1701 	.config_port	= s3c24xx_serial_config_port,
1702 	.verify_port	= s3c24xx_serial_verify_port,
1703 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1704 	.poll_get_char = s3c24xx_serial_get_poll_char,
1705 	.poll_put_char = s3c24xx_serial_put_poll_char,
1706 #endif
1707 };
1708 
1709 static const struct uart_ops apple_s5l_serial_ops = {
1710 	.pm		= s3c24xx_serial_pm,
1711 	.tx_empty	= s3c24xx_serial_tx_empty,
1712 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1713 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1714 	.stop_tx	= s3c24xx_serial_stop_tx,
1715 	.start_tx	= s3c24xx_serial_start_tx,
1716 	.stop_rx	= s3c24xx_serial_stop_rx,
1717 	.break_ctl	= s3c24xx_serial_break_ctl,
1718 	.startup	= apple_s5l_serial_startup,
1719 	.shutdown	= apple_s5l_serial_shutdown,
1720 	.set_termios	= s3c24xx_serial_set_termios,
1721 	.type		= s3c24xx_serial_type,
1722 	.config_port	= s3c24xx_serial_config_port,
1723 	.verify_port	= s3c24xx_serial_verify_port,
1724 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1725 	.poll_get_char = s3c24xx_serial_get_poll_char,
1726 	.poll_put_char = s3c24xx_serial_put_poll_char,
1727 #endif
1728 };
1729 
1730 static struct uart_driver s3c24xx_uart_drv = {
1731 	.owner		= THIS_MODULE,
1732 	.driver_name	= "s3c2410_serial",
1733 	.nr		= UART_NR,
1734 	.cons		= S3C24XX_SERIAL_CONSOLE,
1735 	.dev_name	= S3C24XX_SERIAL_NAME,
1736 	.major		= S3C24XX_SERIAL_MAJOR,
1737 	.minor		= S3C24XX_SERIAL_MINOR,
1738 };
1739 
1740 static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
1741 
1742 static void s3c24xx_serial_init_port_default(int index)
1743 {
1744 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1745 
1746 	spin_lock_init(&port->lock);
1747 
1748 	port->uartclk = 0;
1749 	port->fifosize = 16;
1750 	port->flags = UPF_BOOT_AUTOCONF;
1751 	port->line = index;
1752 }
1753 
1754 /* s3c24xx_serial_resetport
1755  *
1756  * reset the fifos and other the settings.
1757  */
1758 
1759 static void s3c24xx_serial_resetport(struct uart_port *port,
1760 				     const struct s3c2410_uartcfg *cfg)
1761 {
1762 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1763 	u32 ucon = rd_regl(port, S3C2410_UCON);
1764 
1765 	ucon &= (info->clksel_mask | info->ucon_mask);
1766 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1767 
1768 	/* reset both fifos */
1769 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1770 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1771 
1772 	/* some delay is required after fifo reset */
1773 	udelay(1);
1774 }
1775 
1776 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1777 {
1778 	struct device *dev = ourport->port.dev;
1779 	const struct s3c24xx_uart_info *info = ourport->info;
1780 	char clk_name[MAX_CLK_NAME_LENGTH];
1781 	struct clk *clk;
1782 	int ret;
1783 	u8 clk_sel, clk_num;
1784 
1785 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1786 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1787 		if (!(clk_sel & (1 << clk_num)))
1788 			continue;
1789 
1790 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1791 		clk = clk_get(dev, clk_name);
1792 		if (IS_ERR(clk))
1793 			continue;
1794 
1795 		ret = clk_prepare_enable(clk);
1796 		if (ret) {
1797 			clk_put(clk);
1798 			continue;
1799 		}
1800 
1801 		ourport->baudclk = clk;
1802 		ourport->baudclk_rate = clk_get_rate(clk);
1803 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1804 
1805 		return 0;
1806 	}
1807 
1808 	return -EINVAL;
1809 }
1810 
1811 /* s3c24xx_serial_init_port
1812  *
1813  * initialise a single serial port from the platform device given
1814  */
1815 
1816 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1817 				    struct platform_device *platdev)
1818 {
1819 	struct uart_port *port = &ourport->port;
1820 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1821 	struct resource *res;
1822 	int ret;
1823 
1824 	if (platdev == NULL)
1825 		return -ENODEV;
1826 
1827 	if (port->mapbase != 0)
1828 		return -EINVAL;
1829 
1830 	/* setup info for port */
1831 	port->dev	= &platdev->dev;
1832 
1833 	port->uartclk = 1;
1834 
1835 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1836 		dev_dbg(port->dev, "enabling flow control\n");
1837 		port->flags |= UPF_CONS_FLOW;
1838 	}
1839 
1840 	/* sort our the physical and virtual addresses for each UART */
1841 
1842 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1843 	if (res == NULL) {
1844 		dev_err(port->dev, "failed to find memory resource for uart\n");
1845 		return -EINVAL;
1846 	}
1847 
1848 	dev_dbg(port->dev, "resource %pR)\n", res);
1849 
1850 	port->membase = devm_ioremap_resource(port->dev, res);
1851 	if (IS_ERR(port->membase)) {
1852 		dev_err(port->dev, "failed to remap controller address\n");
1853 		return -EBUSY;
1854 	}
1855 
1856 	port->mapbase = res->start;
1857 	ret = platform_get_irq(platdev, 0);
1858 	if (ret < 0) {
1859 		port->irq = 0;
1860 	} else {
1861 		port->irq = ret;
1862 		ourport->rx_irq = ret;
1863 		ourport->tx_irq = ret + 1;
1864 	}
1865 
1866 	/*
1867 	 * DMA is currently supported only on DT platforms, if DMA properties
1868 	 * are specified.
1869 	 */
1870 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1871 						     "dmas", NULL)) {
1872 		ourport->dma = devm_kzalloc(port->dev,
1873 					    sizeof(*ourport->dma),
1874 					    GFP_KERNEL);
1875 		if (!ourport->dma) {
1876 			ret = -ENOMEM;
1877 			goto err;
1878 		}
1879 	}
1880 
1881 	ourport->clk	= clk_get(&platdev->dev, "uart");
1882 	if (IS_ERR(ourport->clk)) {
1883 		pr_err("%s: Controller clock not found\n",
1884 				dev_name(&platdev->dev));
1885 		ret = PTR_ERR(ourport->clk);
1886 		goto err;
1887 	}
1888 
1889 	ret = clk_prepare_enable(ourport->clk);
1890 	if (ret) {
1891 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1892 		clk_put(ourport->clk);
1893 		goto err;
1894 	}
1895 
1896 	ret = s3c24xx_serial_enable_baudclk(ourport);
1897 	if (ret)
1898 		pr_warn("uart: failed to enable baudclk\n");
1899 
1900 	/* Keep all interrupts masked and cleared */
1901 	switch (ourport->info->type) {
1902 	case TYPE_S3C6400:
1903 		wr_regl(port, S3C64XX_UINTM, 0xf);
1904 		wr_regl(port, S3C64XX_UINTP, 0xf);
1905 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1906 		break;
1907 	case TYPE_APPLE_S5L: {
1908 		u32 ucon;
1909 
1910 		ucon = rd_regl(port, S3C2410_UCON);
1911 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1912 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1913 			APPLE_S5L_UCON_RXTO_ENA_MSK);
1914 		wr_regl(port, S3C2410_UCON, ucon);
1915 
1916 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1917 		break;
1918 	}
1919 	default:
1920 		break;
1921 	}
1922 
1923 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1924 		&port->mapbase, port->membase, port->irq,
1925 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
1926 
1927 	/* reset the fifos (and setup the uart) */
1928 	s3c24xx_serial_resetport(port, cfg);
1929 
1930 	return 0;
1931 
1932 err:
1933 	port->mapbase = 0;
1934 	return ret;
1935 }
1936 
1937 /* Device driver serial port probe */
1938 
1939 static int probe_index;
1940 
1941 static inline const struct s3c24xx_serial_drv_data *
1942 s3c24xx_get_driver_data(struct platform_device *pdev)
1943 {
1944 	if (dev_of_node(&pdev->dev))
1945 		return of_device_get_match_data(&pdev->dev);
1946 
1947 	return (struct s3c24xx_serial_drv_data *)
1948 			platform_get_device_id(pdev)->driver_data;
1949 }
1950 
1951 static int s3c24xx_serial_probe(struct platform_device *pdev)
1952 {
1953 	struct device_node *np = pdev->dev.of_node;
1954 	struct s3c24xx_uart_port *ourport;
1955 	int index = probe_index;
1956 	int ret, prop = 0, fifosize_prop = 1;
1957 
1958 	if (np) {
1959 		ret = of_alias_get_id(np, "serial");
1960 		if (ret >= 0)
1961 			index = ret;
1962 	}
1963 
1964 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
1965 		dev_err(&pdev->dev, "serial%d out of range\n", index);
1966 		return -EINVAL;
1967 	}
1968 	ourport = &s3c24xx_serial_ports[index];
1969 
1970 	s3c24xx_serial_init_port_default(index);
1971 
1972 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
1973 	if (!ourport->drv_data) {
1974 		dev_err(&pdev->dev, "could not find driver data\n");
1975 		return -ENODEV;
1976 	}
1977 
1978 	ourport->baudclk = ERR_PTR(-EINVAL);
1979 	ourport->info = &ourport->drv_data->info;
1980 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1981 			dev_get_platdata(&pdev->dev) :
1982 			&ourport->drv_data->def_cfg;
1983 
1984 	switch (ourport->info->type) {
1985 	case TYPE_S3C6400:
1986 		ourport->port.ops = &s3c64xx_serial_ops;
1987 		break;
1988 	case TYPE_APPLE_S5L:
1989 		ourport->port.ops = &apple_s5l_serial_ops;
1990 		break;
1991 	}
1992 
1993 	ourport->port.iotype = ourport->info->iotype;
1994 
1995 	if (np) {
1996 		fifosize_prop = of_property_read_u32(np, "samsung,uart-fifosize",
1997 				&ourport->port.fifosize);
1998 
1999 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2000 			switch (prop) {
2001 			case 1:
2002 				ourport->port.iotype = UPIO_MEM;
2003 				break;
2004 			case 4:
2005 				ourport->port.iotype = UPIO_MEM32;
2006 				break;
2007 			default:
2008 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2009 						prop);
2010 				return -EINVAL;
2011 			}
2012 		}
2013 	}
2014 
2015 	if (fifosize_prop) {
2016 		if (ourport->drv_data->fifosize[index])
2017 			ourport->port.fifosize = ourport->drv_data->fifosize[index];
2018 		else if (ourport->info->fifosize)
2019 			ourport->port.fifosize = ourport->info->fifosize;
2020 	}
2021 
2022 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2023 
2024 	/*
2025 	 * DMA transfers must be aligned at least to cache line size,
2026 	 * so find minimal transfer size suitable for DMA mode
2027 	 */
2028 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2029 				    dma_get_cache_alignment());
2030 
2031 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2032 
2033 	ret = s3c24xx_serial_init_port(ourport, pdev);
2034 	if (ret < 0)
2035 		return ret;
2036 
2037 	if (!s3c24xx_uart_drv.state) {
2038 		ret = uart_register_driver(&s3c24xx_uart_drv);
2039 		if (ret < 0) {
2040 			pr_err("Failed to register Samsung UART driver\n");
2041 			return ret;
2042 		}
2043 	}
2044 
2045 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2046 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2047 	platform_set_drvdata(pdev, &ourport->port);
2048 
2049 	/*
2050 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2051 	 * so that a potential re-enablement through the pm-callback overlaps
2052 	 * and keeps the clock enabled in this case.
2053 	 */
2054 	clk_disable_unprepare(ourport->clk);
2055 	if (!IS_ERR(ourport->baudclk))
2056 		clk_disable_unprepare(ourport->baudclk);
2057 
2058 	probe_index++;
2059 
2060 	return 0;
2061 }
2062 
2063 static void s3c24xx_serial_remove(struct platform_device *dev)
2064 {
2065 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2066 
2067 	if (port)
2068 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2069 
2070 	uart_unregister_driver(&s3c24xx_uart_drv);
2071 }
2072 
2073 /* UART power management code */
2074 #ifdef CONFIG_PM_SLEEP
2075 static int s3c24xx_serial_suspend(struct device *dev)
2076 {
2077 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2078 
2079 	if (port)
2080 		uart_suspend_port(&s3c24xx_uart_drv, port);
2081 
2082 	return 0;
2083 }
2084 
2085 static int s3c24xx_serial_resume(struct device *dev)
2086 {
2087 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2088 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2089 
2090 	if (port) {
2091 		clk_prepare_enable(ourport->clk);
2092 		if (!IS_ERR(ourport->baudclk))
2093 			clk_prepare_enable(ourport->baudclk);
2094 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2095 		if (!IS_ERR(ourport->baudclk))
2096 			clk_disable_unprepare(ourport->baudclk);
2097 		clk_disable_unprepare(ourport->clk);
2098 
2099 		uart_resume_port(&s3c24xx_uart_drv, port);
2100 	}
2101 
2102 	return 0;
2103 }
2104 
2105 static int s3c24xx_serial_resume_noirq(struct device *dev)
2106 {
2107 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2108 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2109 
2110 	if (port) {
2111 		/* restore IRQ mask */
2112 		switch (ourport->info->type) {
2113 		case TYPE_S3C6400: {
2114 			u32 uintm = 0xf;
2115 
2116 			if (ourport->tx_enabled)
2117 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2118 			if (ourport->rx_enabled)
2119 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2120 			clk_prepare_enable(ourport->clk);
2121 			if (!IS_ERR(ourport->baudclk))
2122 				clk_prepare_enable(ourport->baudclk);
2123 			wr_regl(port, S3C64XX_UINTM, uintm);
2124 			if (!IS_ERR(ourport->baudclk))
2125 				clk_disable_unprepare(ourport->baudclk);
2126 			clk_disable_unprepare(ourport->clk);
2127 			break;
2128 		}
2129 		case TYPE_APPLE_S5L: {
2130 			u32 ucon;
2131 			int ret;
2132 
2133 			ret = clk_prepare_enable(ourport->clk);
2134 			if (ret) {
2135 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2136 				return ret;
2137 			}
2138 			if (!IS_ERR(ourport->baudclk)) {
2139 				ret = clk_prepare_enable(ourport->baudclk);
2140 				if (ret) {
2141 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2142 					clk_disable_unprepare(ourport->clk);
2143 					return ret;
2144 				}
2145 			}
2146 
2147 			ucon = rd_regl(port, S3C2410_UCON);
2148 
2149 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2150 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2151 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2152 
2153 			if (ourport->tx_enabled)
2154 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2155 			if (ourport->rx_enabled)
2156 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2157 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2158 
2159 			wr_regl(port, S3C2410_UCON, ucon);
2160 
2161 			if (!IS_ERR(ourport->baudclk))
2162 				clk_disable_unprepare(ourport->baudclk);
2163 			clk_disable_unprepare(ourport->clk);
2164 			break;
2165 		}
2166 		default:
2167 			break;
2168 		}
2169 	}
2170 
2171 	return 0;
2172 }
2173 
2174 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2175 	SET_SYSTEM_SLEEP_PM_OPS(s3c24xx_serial_suspend, s3c24xx_serial_resume)
2176 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, s3c24xx_serial_resume_noirq)
2177 };
2178 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2179 
2180 #else /* !CONFIG_PM_SLEEP */
2181 
2182 #define SERIAL_SAMSUNG_PM_OPS	NULL
2183 #endif /* CONFIG_PM_SLEEP */
2184 
2185 /* Console code */
2186 
2187 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2188 
2189 static struct uart_port *cons_uart;
2190 
2191 static bool
2192 s3c24xx_serial_console_txrdy(struct uart_port *port, u32 ufcon)
2193 {
2194 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2195 	u32 ufstat, utrstat;
2196 
2197 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2198 		/* fifo mode - check amount of data in fifo registers... */
2199 
2200 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2201 		return !(ufstat & info->tx_fifofull);
2202 	}
2203 
2204 	/* in non-fifo mode, we go and use the tx buffer empty */
2205 
2206 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2207 	return utrstat & S3C2410_UTRSTAT_TXE;
2208 }
2209 
2210 static bool
2211 s3c24xx_port_configured(u32 ucon)
2212 {
2213 	/* consider the serial port configured if the tx/rx mode set */
2214 	return (ucon & 0xf) != 0;
2215 }
2216 
2217 #ifdef CONFIG_CONSOLE_POLL
2218 /*
2219  * Console polling routines for writing and reading from the uart while
2220  * in an interrupt or debug context.
2221  */
2222 
2223 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2224 {
2225 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2226 	u32 ufstat;
2227 
2228 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2229 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2230 		return NO_POLL_CHAR;
2231 
2232 	return rd_reg(port, S3C2410_URXH);
2233 }
2234 
2235 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2236 		unsigned char c)
2237 {
2238 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
2239 	u32 ucon = rd_regl(port, S3C2410_UCON);
2240 
2241 	/* not possible to xmit on unconfigured port */
2242 	if (!s3c24xx_port_configured(ucon))
2243 		return;
2244 
2245 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2246 		cpu_relax();
2247 	wr_reg(port, S3C2410_UTXH, c);
2248 }
2249 
2250 #endif /* CONFIG_CONSOLE_POLL */
2251 
2252 static void
2253 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2254 {
2255 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
2256 
2257 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2258 		cpu_relax();
2259 	wr_reg(port, S3C2410_UTXH, ch);
2260 }
2261 
2262 static void
2263 s3c24xx_serial_console_write(struct console *co, const char *s,
2264 			     unsigned int count)
2265 {
2266 	u32 ucon = rd_regl(cons_uart, S3C2410_UCON);
2267 	unsigned long flags;
2268 	bool locked = true;
2269 
2270 	/* not possible to xmit on unconfigured port */
2271 	if (!s3c24xx_port_configured(ucon))
2272 		return;
2273 
2274 	if (cons_uart->sysrq)
2275 		locked = false;
2276 	else if (oops_in_progress)
2277 		locked = uart_port_trylock_irqsave(cons_uart, &flags);
2278 	else
2279 		uart_port_lock_irqsave(cons_uart, &flags);
2280 
2281 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2282 
2283 	if (locked)
2284 		uart_port_unlock_irqrestore(cons_uart, flags);
2285 }
2286 
2287 /* Shouldn't be __init, as it can be instantiated from other module */
2288 static void
2289 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2290 			   int *parity, int *bits)
2291 {
2292 	struct clk *clk;
2293 	unsigned long rate;
2294 	u32 ulcon, ucon, ubrdiv;
2295 	char clk_name[MAX_CLK_NAME_LENGTH];
2296 	u8 clk_sel;
2297 
2298 	ulcon  = rd_regl(port, S3C2410_ULCON);
2299 	ucon   = rd_regl(port, S3C2410_UCON);
2300 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2301 
2302 	if (s3c24xx_port_configured(ucon)) {
2303 		switch (ulcon & S3C2410_LCON_CSMASK) {
2304 		case S3C2410_LCON_CS5:
2305 			*bits = 5;
2306 			break;
2307 		case S3C2410_LCON_CS6:
2308 			*bits = 6;
2309 			break;
2310 		case S3C2410_LCON_CS7:
2311 			*bits = 7;
2312 			break;
2313 		case S3C2410_LCON_CS8:
2314 		default:
2315 			*bits = 8;
2316 			break;
2317 		}
2318 
2319 		switch (ulcon & S3C2410_LCON_PMASK) {
2320 		case S3C2410_LCON_PEVEN:
2321 			*parity = 'e';
2322 			break;
2323 
2324 		case S3C2410_LCON_PODD:
2325 			*parity = 'o';
2326 			break;
2327 
2328 		case S3C2410_LCON_PNONE:
2329 		default:
2330 			*parity = 'n';
2331 		}
2332 
2333 		/* now calculate the baud rate */
2334 
2335 		clk_sel = s3c24xx_serial_getsource(port);
2336 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2337 
2338 		clk = clk_get(port->dev, clk_name);
2339 		if (!IS_ERR(clk))
2340 			rate = clk_get_rate(clk);
2341 		else
2342 			rate = 1;
2343 
2344 		*baud = rate / (16 * (ubrdiv + 1));
2345 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2346 	}
2347 }
2348 
2349 /* Shouldn't be __init, as it can be instantiated from other module */
2350 static int
2351 s3c24xx_serial_console_setup(struct console *co, char *options)
2352 {
2353 	struct uart_port *port;
2354 	int baud = 9600;
2355 	int bits = 8;
2356 	int parity = 'n';
2357 	int flow = 'n';
2358 
2359 	/* is this a valid port */
2360 
2361 	if (co->index == -1 || co->index >= UART_NR)
2362 		co->index = 0;
2363 
2364 	port = &s3c24xx_serial_ports[co->index].port;
2365 
2366 	/* is the port configured? */
2367 
2368 	if (port->mapbase == 0x0)
2369 		return -ENODEV;
2370 
2371 	cons_uart = port;
2372 
2373 	/*
2374 	 * Check whether an invalid uart number has been specified, and
2375 	 * if so, search for the first available port that does have
2376 	 * console support.
2377 	 */
2378 	if (options)
2379 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2380 	else
2381 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2382 
2383 	dev_dbg(port->dev, "baud %d\n", baud);
2384 
2385 	return uart_set_options(port, co, baud, parity, bits, flow);
2386 }
2387 
2388 static struct console s3c24xx_serial_console = {
2389 	.name		= S3C24XX_SERIAL_NAME,
2390 	.device		= uart_console_device,
2391 	.flags		= CON_PRINTBUFFER,
2392 	.index		= -1,
2393 	.write		= s3c24xx_serial_console_write,
2394 	.setup		= s3c24xx_serial_console_setup,
2395 	.data		= &s3c24xx_uart_drv,
2396 };
2397 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2398 
2399 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2400 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2401 	.info = {
2402 		.name		= "Samsung S3C6400 UART",
2403 		.type		= TYPE_S3C6400,
2404 		.port_type	= PORT_S3C6400,
2405 		.iotype		= UPIO_MEM,
2406 		.fifosize	= 64,
2407 		.has_divslot	= true,
2408 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2409 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2410 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2411 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2412 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2413 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2414 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2415 		.num_clks	= 4,
2416 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2417 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2418 	},
2419 	.def_cfg = {
2420 		.ucon		= S3C2410_UCON_DEFAULT,
2421 		.ufcon		= S3C2410_UFCON_DEFAULT,
2422 	},
2423 };
2424 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2425 #else
2426 #define S3C6400_SERIAL_DRV_DATA NULL
2427 #endif
2428 
2429 #ifdef CONFIG_CPU_S5PV210
2430 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2431 	.info = {
2432 		.name		= "Samsung S5PV210 UART",
2433 		.type		= TYPE_S3C6400,
2434 		.port_type	= PORT_S3C6400,
2435 		.iotype		= UPIO_MEM,
2436 		.has_divslot	= true,
2437 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2438 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2439 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2440 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2441 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2442 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2443 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2444 		.num_clks	= 2,
2445 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2446 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2447 	},
2448 	.def_cfg = {
2449 		.ucon		= S5PV210_UCON_DEFAULT,
2450 		.ufcon		= S5PV210_UFCON_DEFAULT,
2451 	},
2452 	.fifosize = { 256, 64, 16, 16 },
2453 };
2454 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2455 #else
2456 #define S5PV210_SERIAL_DRV_DATA	NULL
2457 #endif
2458 
2459 #if defined(CONFIG_ARCH_EXYNOS)
2460 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2461 	.info = {						\
2462 		.name		= "Samsung Exynos UART",	\
2463 		.type		= TYPE_S3C6400,			\
2464 		.port_type	= PORT_S3C6400,			\
2465 		.iotype		= UPIO_MEM,			\
2466 		.has_divslot	= true,				\
2467 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2468 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2469 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2470 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2471 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2472 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2473 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2474 		.num_clks	= 1,				\
2475 		.clksel_mask	= 0,				\
2476 		.clksel_shift	= 0,				\
2477 	},							\
2478 	.def_cfg = {						\
2479 		.ucon		= S5PV210_UCON_DEFAULT,		\
2480 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2481 		.has_fracval	= 1,				\
2482 	}							\
2483 
2484 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2485 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2486 	.fifosize = { 256, 64, 16, 16 },
2487 };
2488 
2489 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2490 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2491 	.fifosize = { 64, 256, 16, 256 },
2492 };
2493 
2494 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2495 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2496 	.fifosize = { 256, 64, 64, 64 },
2497 };
2498 
2499 static const struct s3c24xx_serial_drv_data gs101_serial_drv_data = {
2500 	.info = {
2501 		.name		= "Google GS101 UART",
2502 		.type		= TYPE_S3C6400,
2503 		.port_type	= PORT_S3C6400,
2504 		.iotype		= UPIO_MEM32,
2505 		.has_divslot	= true,
2506 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2507 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2508 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2509 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2510 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2511 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2512 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2513 		.num_clks	= 1,
2514 		.clksel_mask	= 0,
2515 		.clksel_shift	= 0,
2516 	},
2517 	.def_cfg = {
2518 		.ucon		= S5PV210_UCON_DEFAULT,
2519 		.ufcon		= S5PV210_UFCON_DEFAULT,
2520 		.has_fracval	= 1,
2521 	},
2522 	/* samsung,uart-fifosize must be specified in the device tree. */
2523 	.fifosize = { 0 },
2524 };
2525 
2526 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2527 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2528 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2529 #define GS101_SERIAL_DRV_DATA (&gs101_serial_drv_data)
2530 
2531 #else
2532 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2533 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2534 #define EXYNOS850_SERIAL_DRV_DATA NULL
2535 #define GS101_SERIAL_DRV_DATA NULL
2536 #endif
2537 
2538 #ifdef CONFIG_ARCH_APPLE
2539 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2540 	.info = {
2541 		.name		= "Apple S5L UART",
2542 		.type		= TYPE_APPLE_S5L,
2543 		.port_type	= PORT_8250,
2544 		.iotype		= UPIO_MEM,
2545 		.fifosize	= 16,
2546 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2547 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2548 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2549 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2550 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2551 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2552 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2553 		.num_clks	= 1,
2554 		.clksel_mask	= 0,
2555 		.clksel_shift	= 0,
2556 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2557 	},
2558 	.def_cfg = {
2559 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2560 		.ufcon		= S3C2410_UFCON_DEFAULT,
2561 	},
2562 };
2563 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2564 #else
2565 #define S5L_SERIAL_DRV_DATA NULL
2566 #endif
2567 
2568 #if defined(CONFIG_ARCH_ARTPEC)
2569 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2570 	.info = {
2571 		.name		= "Axis ARTPEC-8 UART",
2572 		.type		= TYPE_S3C6400,
2573 		.port_type	= PORT_S3C6400,
2574 		.iotype		= UPIO_MEM,
2575 		.fifosize	= 64,
2576 		.has_divslot	= true,
2577 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2578 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2579 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2580 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2581 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2582 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2583 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2584 		.num_clks	= 1,
2585 		.clksel_mask	= 0,
2586 		.clksel_shift	= 0,
2587 	},
2588 	.def_cfg = {
2589 		.ucon		= S5PV210_UCON_DEFAULT,
2590 		.ufcon		= S5PV210_UFCON_DEFAULT,
2591 		.has_fracval	= 1,
2592 	}
2593 };
2594 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2595 #else
2596 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2597 #endif
2598 
2599 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2600 	{
2601 		.name		= "s3c6400-uart",
2602 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2603 	}, {
2604 		.name		= "s5pv210-uart",
2605 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2606 	}, {
2607 		.name		= "exynos4210-uart",
2608 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2609 	}, {
2610 		.name		= "exynos5433-uart",
2611 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2612 	}, {
2613 		.name		= "s5l-uart",
2614 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2615 	}, {
2616 		.name		= "exynos850-uart",
2617 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2618 	}, {
2619 		.name		= "artpec8-uart",
2620 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2621 	}, {
2622 		.name		= "gs101-uart",
2623 		.driver_data	= (kernel_ulong_t)GS101_SERIAL_DRV_DATA,
2624 	},
2625 	{ },
2626 };
2627 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2628 
2629 #ifdef CONFIG_OF
2630 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2631 	{ .compatible = "samsung,s3c6400-uart",
2632 		.data = S3C6400_SERIAL_DRV_DATA },
2633 	{ .compatible = "samsung,s5pv210-uart",
2634 		.data = S5PV210_SERIAL_DRV_DATA },
2635 	{ .compatible = "samsung,exynos4210-uart",
2636 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2637 	{ .compatible = "samsung,exynos5433-uart",
2638 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2639 	{ .compatible = "apple,s5l-uart",
2640 		.data = S5L_SERIAL_DRV_DATA },
2641 	{ .compatible = "samsung,exynos850-uart",
2642 		.data = EXYNOS850_SERIAL_DRV_DATA },
2643 	{ .compatible = "axis,artpec8-uart",
2644 		.data = ARTPEC8_SERIAL_DRV_DATA },
2645 	{ .compatible = "google,gs101-uart",
2646 		.data = GS101_SERIAL_DRV_DATA },
2647 	{},
2648 };
2649 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2650 #endif
2651 
2652 static struct platform_driver samsung_serial_driver = {
2653 	.probe		= s3c24xx_serial_probe,
2654 	.remove_new	= s3c24xx_serial_remove,
2655 	.id_table	= s3c24xx_serial_driver_ids,
2656 	.driver		= {
2657 		.name	= "samsung-uart",
2658 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2659 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2660 	},
2661 };
2662 
2663 static int __init samsung_serial_init(void)
2664 {
2665 	int ret;
2666 
2667 	s3c24xx_serial_register_console();
2668 
2669 	ret = platform_driver_register(&samsung_serial_driver);
2670 	if (ret) {
2671 		s3c24xx_serial_unregister_console();
2672 		return ret;
2673 	}
2674 
2675 	return 0;
2676 }
2677 
2678 static void __exit samsung_serial_exit(void)
2679 {
2680 	platform_driver_unregister(&samsung_serial_driver);
2681 	s3c24xx_serial_unregister_console();
2682 }
2683 
2684 module_init(samsung_serial_init);
2685 module_exit(samsung_serial_exit);
2686 
2687 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2688 /*
2689  * Early console.
2690  */
2691 
2692 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2693 {
2694 	switch (port->iotype) {
2695 	case UPIO_MEM:
2696 		writeb(val, portaddr(port, reg));
2697 		break;
2698 	case UPIO_MEM32:
2699 		writel(val, portaddr(port, reg));
2700 		break;
2701 	}
2702 }
2703 
2704 struct samsung_early_console_data {
2705 	u32 txfull_mask;
2706 	u32 rxfifo_mask;
2707 };
2708 
2709 static void samsung_early_busyuart(const struct uart_port *port)
2710 {
2711 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2712 		;
2713 }
2714 
2715 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2716 {
2717 	const struct samsung_early_console_data *data = port->private_data;
2718 
2719 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2720 		;
2721 }
2722 
2723 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2724 {
2725 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2726 		samsung_early_busyuart_fifo(port);
2727 	else
2728 		samsung_early_busyuart(port);
2729 
2730 	wr_reg_barrier(port, S3C2410_UTXH, c);
2731 }
2732 
2733 static void samsung_early_write(struct console *con, const char *s,
2734 				unsigned int n)
2735 {
2736 	struct earlycon_device *dev = con->data;
2737 
2738 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2739 }
2740 
2741 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2742 {
2743 	struct earlycon_device *dev = con->data;
2744 	const struct samsung_early_console_data *data = dev->port.private_data;
2745 	int num_read = 0;
2746 	u32 ch, ufstat;
2747 
2748 	while (num_read < n) {
2749 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
2750 		if (!(ufstat & data->rxfifo_mask))
2751 			break;
2752 		ch = rd_reg(&dev->port, S3C2410_URXH);
2753 		if (ch == NO_POLL_CHAR)
2754 			break;
2755 
2756 		s[num_read++] = ch;
2757 	}
2758 
2759 	return num_read;
2760 }
2761 
2762 static int __init samsung_early_console_setup(struct earlycon_device *device,
2763 					      const char *opt)
2764 {
2765 	if (!device->port.membase)
2766 		return -ENODEV;
2767 
2768 	device->con->write = samsung_early_write;
2769 	device->con->read = samsung_early_read;
2770 	return 0;
2771 }
2772 
2773 /* S3C2410 */
2774 static struct samsung_early_console_data s3c2410_early_console_data = {
2775 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2776 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
2777 };
2778 
2779 /* S3C64xx */
2780 static struct samsung_early_console_data s3c2440_early_console_data = {
2781 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2782 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
2783 };
2784 
2785 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2786 					      const char *opt)
2787 {
2788 	device->port.private_data = &s3c2440_early_console_data;
2789 	return samsung_early_console_setup(device, opt);
2790 }
2791 
2792 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2793 			s3c2440_early_console_setup);
2794 
2795 /* S5PV210, Exynos */
2796 static struct samsung_early_console_data s5pv210_early_console_data = {
2797 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2798 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
2799 };
2800 
2801 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2802 					      const char *opt)
2803 {
2804 	device->port.private_data = &s5pv210_early_console_data;
2805 	return samsung_early_console_setup(device, opt);
2806 }
2807 
2808 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2809 			s5pv210_early_console_setup);
2810 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2811 			s5pv210_early_console_setup);
2812 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
2813 			s5pv210_early_console_setup);
2814 
2815 static int __init gs101_early_console_setup(struct earlycon_device *device,
2816 					    const char *opt)
2817 {
2818 	/* gs101 always expects MMIO32 register accesses. */
2819 	device->port.iotype = UPIO_MEM32;
2820 
2821 	return s5pv210_early_console_setup(device, opt);
2822 }
2823 
2824 OF_EARLYCON_DECLARE(gs101, "google,gs101-uart", gs101_early_console_setup);
2825 
2826 /* Apple S5L */
2827 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
2828 						const char *opt)
2829 {
2830 	/* Close enough to S3C2410 for earlycon... */
2831 	device->port.private_data = &s3c2410_early_console_data;
2832 
2833 #ifdef CONFIG_ARM64
2834 	/* ... but we need to override the existing fixmap entry as nGnRnE */
2835 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
2836 		     __pgprot(PROT_DEVICE_nGnRnE));
2837 #endif
2838 	return samsung_early_console_setup(device, opt);
2839 }
2840 
2841 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
2842 #endif
2843 
2844 MODULE_ALIAS("platform:samsung-uart");
2845 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2846 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2847 MODULE_LICENSE("GPL v2");
2848