xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision 17bfcd6a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Note on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/math.h>
28 #include <linux/module.h>
29 #include <linux/ioport.h>
30 #include <linux/io.h>
31 #include <linux/platform_device.h>
32 #include <linux/init.h>
33 #include <linux/sysrq.h>
34 #include <linux/console.h>
35 #include <linux/tty.h>
36 #include <linux/tty_flip.h>
37 #include <linux/serial_core.h>
38 #include <linux/serial.h>
39 #include <linux/serial_s3c.h>
40 #include <linux/delay.h>
41 #include <linux/clk.h>
42 #include <linux/cpufreq.h>
43 #include <linux/of.h>
44 #include <asm/irq.h>
45 
46 /* UART name and device definitions */
47 
48 #define S3C24XX_SERIAL_NAME	"ttySAC"
49 #define S3C24XX_SERIAL_MAJOR	204
50 #define S3C24XX_SERIAL_MINOR	64
51 
52 #ifdef CONFIG_ARM64
53 #define UART_NR			12
54 #else
55 #define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
56 #endif
57 
58 #define S3C24XX_TX_PIO			1
59 #define S3C24XX_TX_DMA			2
60 #define S3C24XX_RX_PIO			1
61 #define S3C24XX_RX_DMA			2
62 
63 /* flag to ignore all characters coming in */
64 #define RXSTAT_DUMMY_READ (0x10000000)
65 
66 enum s3c24xx_port_type {
67 	TYPE_S3C24XX,
68 	TYPE_S3C6400,
69 	TYPE_APPLE_S5L,
70 };
71 
72 struct s3c24xx_uart_info {
73 	const char		*name;
74 	enum s3c24xx_port_type	type;
75 	unsigned int		port_type;
76 	unsigned int		fifosize;
77 	unsigned long		rx_fifomask;
78 	unsigned long		rx_fifoshift;
79 	unsigned long		rx_fifofull;
80 	unsigned long		tx_fifomask;
81 	unsigned long		tx_fifoshift;
82 	unsigned long		tx_fifofull;
83 	unsigned int		def_clk_sel;
84 	unsigned long		num_clks;
85 	unsigned long		clksel_mask;
86 	unsigned long		clksel_shift;
87 	unsigned long		ucon_mask;
88 
89 	/* uart port features */
90 
91 	unsigned int		has_divslot:1;
92 };
93 
94 struct s3c24xx_serial_drv_data {
95 	const struct s3c24xx_uart_info	info;
96 	const struct s3c2410_uartcfg	def_cfg;
97 	const unsigned int		fifosize[UART_NR];
98 };
99 
100 struct s3c24xx_uart_dma {
101 	unsigned int			rx_chan_id;
102 	unsigned int			tx_chan_id;
103 
104 	struct dma_slave_config		rx_conf;
105 	struct dma_slave_config		tx_conf;
106 
107 	struct dma_chan			*rx_chan;
108 	struct dma_chan			*tx_chan;
109 
110 	dma_addr_t			rx_addr;
111 	dma_addr_t			tx_addr;
112 
113 	dma_cookie_t			rx_cookie;
114 	dma_cookie_t			tx_cookie;
115 
116 	char				*rx_buf;
117 
118 	dma_addr_t			tx_transfer_addr;
119 
120 	size_t				rx_size;
121 	size_t				tx_size;
122 
123 	struct dma_async_tx_descriptor	*tx_desc;
124 	struct dma_async_tx_descriptor	*rx_desc;
125 
126 	int				tx_bytes_requested;
127 	int				rx_bytes_requested;
128 };
129 
130 struct s3c24xx_uart_port {
131 	unsigned char			rx_claimed;
132 	unsigned char			tx_claimed;
133 	unsigned char			rx_enabled;
134 	unsigned char			tx_enabled;
135 	unsigned int			pm_level;
136 	unsigned long			baudclk_rate;
137 	unsigned int			min_dma_size;
138 
139 	unsigned int			rx_irq;
140 	unsigned int			tx_irq;
141 
142 	unsigned int			tx_in_progress;
143 	unsigned int			tx_mode;
144 	unsigned int			rx_mode;
145 
146 	const struct s3c24xx_uart_info	*info;
147 	struct clk			*clk;
148 	struct clk			*baudclk;
149 	struct uart_port		port;
150 	const struct s3c24xx_serial_drv_data	*drv_data;
151 
152 	/* reference to platform data */
153 	const struct s3c2410_uartcfg	*cfg;
154 
155 	struct s3c24xx_uart_dma		*dma;
156 };
157 
158 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
159 
160 /* conversion functions */
161 
162 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
163 
164 /* register access controls */
165 
166 #define portaddr(port, reg) ((port)->membase + (reg))
167 #define portaddrl(port, reg) \
168 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
169 
170 static u32 rd_reg(const struct uart_port *port, u32 reg)
171 {
172 	switch (port->iotype) {
173 	case UPIO_MEM:
174 		return readb_relaxed(portaddr(port, reg));
175 	case UPIO_MEM32:
176 		return readl_relaxed(portaddr(port, reg));
177 	default:
178 		return 0;
179 	}
180 	return 0;
181 }
182 
183 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
184 
185 static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
186 {
187 	switch (port->iotype) {
188 	case UPIO_MEM:
189 		writeb_relaxed(val, portaddr(port, reg));
190 		break;
191 	case UPIO_MEM32:
192 		writel_relaxed(val, portaddr(port, reg));
193 		break;
194 	}
195 }
196 
197 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
198 
199 /* Byte-order aware bit setting/clearing functions. */
200 
201 static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
202 				   unsigned int reg)
203 {
204 	unsigned long flags;
205 	u32 val;
206 
207 	local_irq_save(flags);
208 	val = rd_regl(port, reg);
209 	val |= (1 << idx);
210 	wr_regl(port, reg, val);
211 	local_irq_restore(flags);
212 }
213 
214 static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
215 				     unsigned int reg)
216 {
217 	unsigned long flags;
218 	u32 val;
219 
220 	local_irq_save(flags);
221 	val = rd_regl(port, reg);
222 	val &= ~(1 << idx);
223 	wr_regl(port, reg, val);
224 	local_irq_restore(flags);
225 }
226 
227 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
228 {
229 	return container_of(port, struct s3c24xx_uart_port, port);
230 }
231 
232 /* translate a port to the device name */
233 
234 static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
235 {
236 	return to_platform_device(port->dev)->name;
237 }
238 
239 static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
240 {
241 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
242 }
243 
244 static void s3c24xx_serial_rx_enable(struct uart_port *port)
245 {
246 	struct s3c24xx_uart_port *ourport = to_ourport(port);
247 	unsigned long flags;
248 	unsigned int ucon, ufcon;
249 	int count = 10000;
250 
251 	spin_lock_irqsave(&port->lock, flags);
252 
253 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
254 		udelay(100);
255 
256 	ufcon = rd_regl(port, S3C2410_UFCON);
257 	ufcon |= S3C2410_UFCON_RESETRX;
258 	wr_regl(port, S3C2410_UFCON, ufcon);
259 
260 	ucon = rd_regl(port, S3C2410_UCON);
261 	ucon |= S3C2410_UCON_RXIRQMODE;
262 	wr_regl(port, S3C2410_UCON, ucon);
263 
264 	ourport->rx_enabled = 1;
265 	spin_unlock_irqrestore(&port->lock, flags);
266 }
267 
268 static void s3c24xx_serial_rx_disable(struct uart_port *port)
269 {
270 	struct s3c24xx_uart_port *ourport = to_ourport(port);
271 	unsigned long flags;
272 	unsigned int ucon;
273 
274 	spin_lock_irqsave(&port->lock, flags);
275 
276 	ucon = rd_regl(port, S3C2410_UCON);
277 	ucon &= ~S3C2410_UCON_RXIRQMODE;
278 	wr_regl(port, S3C2410_UCON, ucon);
279 
280 	ourport->rx_enabled = 0;
281 	spin_unlock_irqrestore(&port->lock, flags);
282 }
283 
284 static void s3c24xx_serial_stop_tx(struct uart_port *port)
285 {
286 	struct s3c24xx_uart_port *ourport = to_ourport(port);
287 	struct s3c24xx_uart_dma *dma = ourport->dma;
288 	struct dma_tx_state state;
289 	int count;
290 
291 	if (!ourport->tx_enabled)
292 		return;
293 
294 	switch (ourport->info->type) {
295 	case TYPE_S3C6400:
296 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
297 		break;
298 	case TYPE_APPLE_S5L:
299 		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
300 		break;
301 	default:
302 		disable_irq_nosync(ourport->tx_irq);
303 		break;
304 	}
305 
306 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
307 		dmaengine_pause(dma->tx_chan);
308 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
309 		dmaengine_terminate_all(dma->tx_chan);
310 		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
311 					dma->tx_transfer_addr, dma->tx_size,
312 					DMA_TO_DEVICE);
313 		async_tx_ack(dma->tx_desc);
314 		count = dma->tx_bytes_requested - state.residue;
315 		uart_xmit_advance(port, count);
316 	}
317 
318 	ourport->tx_enabled = 0;
319 	ourport->tx_in_progress = 0;
320 
321 	if (port->flags & UPF_CONS_FLOW)
322 		s3c24xx_serial_rx_enable(port);
323 
324 	ourport->tx_mode = 0;
325 }
326 
327 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
328 
329 static void s3c24xx_serial_tx_dma_complete(void *args)
330 {
331 	struct s3c24xx_uart_port *ourport = args;
332 	struct uart_port *port = &ourport->port;
333 	struct circ_buf *xmit = &port->state->xmit;
334 	struct s3c24xx_uart_dma *dma = ourport->dma;
335 	struct dma_tx_state state;
336 	unsigned long flags;
337 	int count;
338 
339 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
340 	count = dma->tx_bytes_requested - state.residue;
341 	async_tx_ack(dma->tx_desc);
342 
343 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
344 				dma->tx_transfer_addr, dma->tx_size,
345 				DMA_TO_DEVICE);
346 
347 	spin_lock_irqsave(&port->lock, flags);
348 
349 	uart_xmit_advance(port, count);
350 	ourport->tx_in_progress = 0;
351 
352 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
353 		uart_write_wakeup(port);
354 
355 	s3c24xx_serial_start_next_tx(ourport);
356 	spin_unlock_irqrestore(&port->lock, flags);
357 }
358 
359 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
360 {
361 	const struct uart_port *port = &ourport->port;
362 	u32 ucon;
363 
364 	/* Mask Tx interrupt */
365 	switch (ourport->info->type) {
366 	case TYPE_S3C6400:
367 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
368 		break;
369 	case TYPE_APPLE_S5L:
370 		WARN_ON(1); // No DMA
371 		break;
372 	default:
373 		disable_irq_nosync(ourport->tx_irq);
374 		break;
375 	}
376 
377 	/* Enable tx dma mode */
378 	ucon = rd_regl(port, S3C2410_UCON);
379 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
380 	ucon |= S3C64XX_UCON_TXBURST_1;
381 	ucon |= S3C64XX_UCON_TXMODE_DMA;
382 	wr_regl(port,  S3C2410_UCON, ucon);
383 
384 	ourport->tx_mode = S3C24XX_TX_DMA;
385 }
386 
387 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
388 {
389 	const struct uart_port *port = &ourport->port;
390 	u32 ucon, ufcon;
391 
392 	/* Set ufcon txtrig */
393 	ourport->tx_in_progress = S3C24XX_TX_PIO;
394 	ufcon = rd_regl(port, S3C2410_UFCON);
395 	wr_regl(port,  S3C2410_UFCON, ufcon);
396 
397 	/* Enable tx pio mode */
398 	ucon = rd_regl(port, S3C2410_UCON);
399 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
400 	ucon |= S3C64XX_UCON_TXMODE_CPU;
401 	wr_regl(port,  S3C2410_UCON, ucon);
402 
403 	/* Unmask Tx interrupt */
404 	switch (ourport->info->type) {
405 	case TYPE_S3C6400:
406 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
407 				  S3C64XX_UINTM);
408 		break;
409 	case TYPE_APPLE_S5L:
410 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
411 		wr_regl(port, S3C2410_UCON, ucon);
412 		break;
413 	default:
414 		enable_irq(ourport->tx_irq);
415 		break;
416 	}
417 
418 	ourport->tx_mode = S3C24XX_TX_PIO;
419 
420 	/*
421 	 * The Apple version only has edge triggered TX IRQs, so we need
422 	 * to kick off the process by sending some characters here.
423 	 */
424 	if (ourport->info->type == TYPE_APPLE_S5L)
425 		s3c24xx_serial_tx_chars(ourport);
426 }
427 
428 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
429 {
430 	if (ourport->tx_mode != S3C24XX_TX_PIO)
431 		enable_tx_pio(ourport);
432 }
433 
434 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
435 				      unsigned int count)
436 {
437 	struct uart_port *port = &ourport->port;
438 	struct circ_buf *xmit = &port->state->xmit;
439 	struct s3c24xx_uart_dma *dma = ourport->dma;
440 
441 	if (ourport->tx_mode != S3C24XX_TX_DMA)
442 		enable_tx_dma(ourport);
443 
444 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
445 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
446 
447 	dma_sync_single_for_device(dma->tx_chan->device->dev,
448 				   dma->tx_transfer_addr, dma->tx_size,
449 				   DMA_TO_DEVICE);
450 
451 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
452 				dma->tx_transfer_addr, dma->tx_size,
453 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
454 	if (!dma->tx_desc) {
455 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
456 		return -EIO;
457 	}
458 
459 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
460 	dma->tx_desc->callback_param = ourport;
461 	dma->tx_bytes_requested = dma->tx_size;
462 
463 	ourport->tx_in_progress = S3C24XX_TX_DMA;
464 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
465 	dma_async_issue_pending(dma->tx_chan);
466 	return 0;
467 }
468 
469 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
470 {
471 	struct uart_port *port = &ourport->port;
472 	struct circ_buf *xmit = &port->state->xmit;
473 	unsigned long count;
474 
475 	/* Get data size up to the end of buffer */
476 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
477 
478 	if (!count) {
479 		s3c24xx_serial_stop_tx(port);
480 		return;
481 	}
482 
483 	if (!ourport->dma || !ourport->dma->tx_chan ||
484 	    count < ourport->min_dma_size ||
485 	    xmit->tail & (dma_get_cache_alignment() - 1))
486 		s3c24xx_serial_start_tx_pio(ourport);
487 	else
488 		s3c24xx_serial_start_tx_dma(ourport, count);
489 }
490 
491 static void s3c24xx_serial_start_tx(struct uart_port *port)
492 {
493 	struct s3c24xx_uart_port *ourport = to_ourport(port);
494 	struct circ_buf *xmit = &port->state->xmit;
495 
496 	if (!ourport->tx_enabled) {
497 		if (port->flags & UPF_CONS_FLOW)
498 			s3c24xx_serial_rx_disable(port);
499 
500 		ourport->tx_enabled = 1;
501 		if (!ourport->dma || !ourport->dma->tx_chan)
502 			s3c24xx_serial_start_tx_pio(ourport);
503 	}
504 
505 	if (ourport->dma && ourport->dma->tx_chan) {
506 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
507 			s3c24xx_serial_start_next_tx(ourport);
508 	}
509 }
510 
511 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
512 		struct tty_port *tty, int count)
513 {
514 	struct s3c24xx_uart_dma *dma = ourport->dma;
515 	int copied;
516 
517 	if (!count)
518 		return;
519 
520 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
521 				dma->rx_size, DMA_FROM_DEVICE);
522 
523 	ourport->port.icount.rx += count;
524 	if (!tty) {
525 		dev_err(ourport->port.dev, "No tty port\n");
526 		return;
527 	}
528 	copied = tty_insert_flip_string(tty,
529 			((unsigned char *)(ourport->dma->rx_buf)), count);
530 	if (copied != count) {
531 		WARN_ON(1);
532 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
533 	}
534 }
535 
536 static void s3c24xx_serial_stop_rx(struct uart_port *port)
537 {
538 	struct s3c24xx_uart_port *ourport = to_ourport(port);
539 	struct s3c24xx_uart_dma *dma = ourport->dma;
540 	struct tty_port *t = &port->state->port;
541 	struct dma_tx_state state;
542 	enum dma_status dma_status;
543 	unsigned int received;
544 
545 	if (ourport->rx_enabled) {
546 		dev_dbg(port->dev, "stopping rx\n");
547 		switch (ourport->info->type) {
548 		case TYPE_S3C6400:
549 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
550 					S3C64XX_UINTM);
551 			break;
552 		case TYPE_APPLE_S5L:
553 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
554 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
555 			break;
556 		default:
557 			disable_irq_nosync(ourport->rx_irq);
558 			break;
559 		}
560 		ourport->rx_enabled = 0;
561 	}
562 	if (dma && dma->rx_chan) {
563 		dmaengine_pause(dma->tx_chan);
564 		dma_status = dmaengine_tx_status(dma->rx_chan,
565 				dma->rx_cookie, &state);
566 		if (dma_status == DMA_IN_PROGRESS ||
567 			dma_status == DMA_PAUSED) {
568 			received = dma->rx_bytes_requested - state.residue;
569 			dmaengine_terminate_all(dma->rx_chan);
570 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
571 		}
572 	}
573 }
574 
575 static inline const struct s3c24xx_uart_info
576 	*s3c24xx_port_to_info(struct uart_port *port)
577 {
578 	return to_ourport(port)->info;
579 }
580 
581 static inline const struct s3c2410_uartcfg
582 	*s3c24xx_port_to_cfg(const struct uart_port *port)
583 {
584 	const struct s3c24xx_uart_port *ourport;
585 
586 	if (port->dev == NULL)
587 		return NULL;
588 
589 	ourport = container_of(port, struct s3c24xx_uart_port, port);
590 	return ourport->cfg;
591 }
592 
593 static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
594 				     unsigned long ufstat)
595 {
596 	const struct s3c24xx_uart_info *info = ourport->info;
597 
598 	if (ufstat & info->rx_fifofull)
599 		return ourport->port.fifosize;
600 
601 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
602 }
603 
604 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
605 static void s3c24xx_serial_rx_dma_complete(void *args)
606 {
607 	struct s3c24xx_uart_port *ourport = args;
608 	struct uart_port *port = &ourport->port;
609 
610 	struct s3c24xx_uart_dma *dma = ourport->dma;
611 	struct tty_port *t = &port->state->port;
612 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
613 
614 	struct dma_tx_state state;
615 	unsigned long flags;
616 	int received;
617 
618 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
619 	received  = dma->rx_bytes_requested - state.residue;
620 	async_tx_ack(dma->rx_desc);
621 
622 	spin_lock_irqsave(&port->lock, flags);
623 
624 	if (received)
625 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
626 
627 	if (tty) {
628 		tty_flip_buffer_push(t);
629 		tty_kref_put(tty);
630 	}
631 
632 	s3c64xx_start_rx_dma(ourport);
633 
634 	spin_unlock_irqrestore(&port->lock, flags);
635 }
636 
637 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
638 {
639 	struct s3c24xx_uart_dma *dma = ourport->dma;
640 
641 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
642 				   dma->rx_size, DMA_FROM_DEVICE);
643 
644 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
645 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
646 				DMA_PREP_INTERRUPT);
647 	if (!dma->rx_desc) {
648 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
649 		return;
650 	}
651 
652 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
653 	dma->rx_desc->callback_param = ourport;
654 	dma->rx_bytes_requested = dma->rx_size;
655 
656 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
657 	dma_async_issue_pending(dma->rx_chan);
658 }
659 
660 /* ? - where has parity gone?? */
661 #define S3C2410_UERSTAT_PARITY (0x1000)
662 
663 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
664 {
665 	struct uart_port *port = &ourport->port;
666 	unsigned int ucon;
667 
668 	/* set Rx mode to DMA mode */
669 	ucon = rd_regl(port, S3C2410_UCON);
670 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
671 			S3C64XX_UCON_TIMEOUT_MASK |
672 			S3C64XX_UCON_EMPTYINT_EN |
673 			S3C64XX_UCON_DMASUS_EN |
674 			S3C64XX_UCON_TIMEOUT_EN |
675 			S3C64XX_UCON_RXMODE_MASK);
676 	ucon |= S3C64XX_UCON_RXBURST_1 |
677 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
678 			S3C64XX_UCON_EMPTYINT_EN |
679 			S3C64XX_UCON_TIMEOUT_EN |
680 			S3C64XX_UCON_RXMODE_DMA;
681 	wr_regl(port, S3C2410_UCON, ucon);
682 
683 	ourport->rx_mode = S3C24XX_RX_DMA;
684 }
685 
686 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
687 {
688 	struct uart_port *port = &ourport->port;
689 	unsigned int ucon;
690 
691 	/* set Rx mode to DMA mode */
692 	ucon = rd_regl(port, S3C2410_UCON);
693 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
694 	ucon |= S3C64XX_UCON_RXMODE_CPU;
695 
696 	/* Apple types use these bits for IRQ masks */
697 	if (ourport->info->type != TYPE_APPLE_S5L) {
698 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
699 				S3C64XX_UCON_EMPTYINT_EN |
700 				S3C64XX_UCON_DMASUS_EN |
701 				S3C64XX_UCON_TIMEOUT_EN);
702 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
703 				S3C64XX_UCON_TIMEOUT_EN;
704 	}
705 	wr_regl(port, S3C2410_UCON, ucon);
706 
707 	ourport->rx_mode = S3C24XX_RX_PIO;
708 }
709 
710 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
711 
712 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
713 {
714 	unsigned int utrstat, received;
715 	struct s3c24xx_uart_port *ourport = dev_id;
716 	struct uart_port *port = &ourport->port;
717 	struct s3c24xx_uart_dma *dma = ourport->dma;
718 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
719 	struct tty_port *t = &port->state->port;
720 	struct dma_tx_state state;
721 
722 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
723 	rd_regl(port, S3C2410_UFSTAT);
724 
725 	spin_lock(&port->lock);
726 
727 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
728 		s3c64xx_start_rx_dma(ourport);
729 		if (ourport->rx_mode == S3C24XX_RX_PIO)
730 			enable_rx_dma(ourport);
731 		goto finish;
732 	}
733 
734 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
735 		dmaengine_pause(dma->rx_chan);
736 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
737 		dmaengine_terminate_all(dma->rx_chan);
738 		received = dma->rx_bytes_requested - state.residue;
739 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
740 
741 		enable_rx_pio(ourport);
742 	}
743 
744 	s3c24xx_serial_rx_drain_fifo(ourport);
745 
746 	if (tty) {
747 		tty_flip_buffer_push(t);
748 		tty_kref_put(tty);
749 	}
750 
751 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
752 
753 finish:
754 	spin_unlock(&port->lock);
755 
756 	return IRQ_HANDLED;
757 }
758 
759 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
760 {
761 	struct uart_port *port = &ourport->port;
762 	unsigned int ufcon, ufstat, uerstat;
763 	unsigned int fifocnt = 0;
764 	int max_count = port->fifosize;
765 	u8 ch, flag;
766 
767 	while (max_count-- > 0) {
768 		/*
769 		 * Receive all characters known to be in FIFO
770 		 * before reading FIFO level again
771 		 */
772 		if (fifocnt == 0) {
773 			ufstat = rd_regl(port, S3C2410_UFSTAT);
774 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
775 			if (fifocnt == 0)
776 				break;
777 		}
778 		fifocnt--;
779 
780 		uerstat = rd_regl(port, S3C2410_UERSTAT);
781 		ch = rd_reg(port, S3C2410_URXH);
782 
783 		if (port->flags & UPF_CONS_FLOW) {
784 			int txe = s3c24xx_serial_txempty_nofifo(port);
785 
786 			if (ourport->rx_enabled) {
787 				if (!txe) {
788 					ourport->rx_enabled = 0;
789 					continue;
790 				}
791 			} else {
792 				if (txe) {
793 					ufcon = rd_regl(port, S3C2410_UFCON);
794 					ufcon |= S3C2410_UFCON_RESETRX;
795 					wr_regl(port, S3C2410_UFCON, ufcon);
796 					ourport->rx_enabled = 1;
797 					return;
798 				}
799 				continue;
800 			}
801 		}
802 
803 		/* insert the character into the buffer */
804 
805 		flag = TTY_NORMAL;
806 		port->icount.rx++;
807 
808 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
809 			dev_dbg(port->dev,
810 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
811 				ch, uerstat);
812 
813 			/* check for break */
814 			if (uerstat & S3C2410_UERSTAT_BREAK) {
815 				dev_dbg(port->dev, "break!\n");
816 				port->icount.brk++;
817 				if (uart_handle_break(port))
818 					continue; /* Ignore character */
819 			}
820 
821 			if (uerstat & S3C2410_UERSTAT_FRAME)
822 				port->icount.frame++;
823 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
824 				port->icount.overrun++;
825 
826 			uerstat &= port->read_status_mask;
827 
828 			if (uerstat & S3C2410_UERSTAT_BREAK)
829 				flag = TTY_BREAK;
830 			else if (uerstat & S3C2410_UERSTAT_PARITY)
831 				flag = TTY_PARITY;
832 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
833 					    S3C2410_UERSTAT_OVERRUN))
834 				flag = TTY_FRAME;
835 		}
836 
837 		if (uart_handle_sysrq_char(port, ch))
838 			continue; /* Ignore character */
839 
840 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
841 				 ch, flag);
842 	}
843 
844 	tty_flip_buffer_push(&port->state->port);
845 }
846 
847 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
848 {
849 	struct s3c24xx_uart_port *ourport = dev_id;
850 	struct uart_port *port = &ourport->port;
851 
852 	spin_lock(&port->lock);
853 	s3c24xx_serial_rx_drain_fifo(ourport);
854 	spin_unlock(&port->lock);
855 
856 	return IRQ_HANDLED;
857 }
858 
859 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
860 {
861 	struct s3c24xx_uart_port *ourport = dev_id;
862 
863 	if (ourport->dma && ourport->dma->rx_chan)
864 		return s3c24xx_serial_rx_chars_dma(dev_id);
865 	return s3c24xx_serial_rx_chars_pio(dev_id);
866 }
867 
868 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
869 {
870 	struct uart_port *port = &ourport->port;
871 	struct circ_buf *xmit = &port->state->xmit;
872 	int count, dma_count = 0;
873 
874 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
875 
876 	if (ourport->dma && ourport->dma->tx_chan &&
877 	    count >= ourport->min_dma_size) {
878 		int align = dma_get_cache_alignment() -
879 			(xmit->tail & (dma_get_cache_alignment() - 1));
880 		if (count - align >= ourport->min_dma_size) {
881 			dma_count = count - align;
882 			count = 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 (uart_circ_empty(xmit) || 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 (!uart_circ_empty(xmit) && count > 0) {
910 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
911 			break;
912 
913 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
914 		uart_xmit_advance(port, 1);
915 		count--;
916 	}
917 
918 	if (!count && dma_count) {
919 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
920 		return;
921 	}
922 
923 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
924 		uart_write_wakeup(port);
925 
926 	if (uart_circ_empty(xmit))
927 		s3c24xx_serial_stop_tx(port);
928 }
929 
930 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
931 {
932 	struct s3c24xx_uart_port *ourport = id;
933 	struct uart_port *port = &ourport->port;
934 
935 	spin_lock(&port->lock);
936 
937 	s3c24xx_serial_tx_chars(ourport);
938 
939 	spin_unlock(&port->lock);
940 	return IRQ_HANDLED;
941 }
942 
943 /* interrupt handler for s3c64xx and later SoC's.*/
944 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
945 {
946 	const struct s3c24xx_uart_port *ourport = id;
947 	const struct uart_port *port = &ourport->port;
948 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
949 	irqreturn_t ret = IRQ_HANDLED;
950 
951 	if (pend & S3C64XX_UINTM_RXD_MSK) {
952 		ret = s3c24xx_serial_rx_irq(irq, id);
953 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
954 	}
955 	if (pend & S3C64XX_UINTM_TXD_MSK) {
956 		ret = s3c24xx_serial_tx_irq(irq, id);
957 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
958 	}
959 	return ret;
960 }
961 
962 /* interrupt handler for Apple SoC's.*/
963 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
964 {
965 	const struct s3c24xx_uart_port *ourport = id;
966 	const struct uart_port *port = &ourport->port;
967 	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
968 	irqreturn_t ret = IRQ_NONE;
969 
970 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
971 		wr_regl(port, S3C2410_UTRSTAT,
972 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
973 		ret = s3c24xx_serial_rx_irq(irq, id);
974 	}
975 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
976 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
977 		ret = s3c24xx_serial_tx_irq(irq, id);
978 	}
979 
980 	return ret;
981 }
982 
983 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
984 {
985 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
986 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
987 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
988 
989 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
990 		if ((ufstat & info->tx_fifomask) != 0 ||
991 		    (ufstat & info->tx_fifofull))
992 			return 0;
993 
994 		return 1;
995 	}
996 
997 	return s3c24xx_serial_txempty_nofifo(port);
998 }
999 
1000 /* no modem control lines */
1001 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1002 {
1003 	unsigned int 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 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
1014 	unsigned int 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 	unsigned int ucon;
1035 
1036 	spin_lock_irqsave(&port->lock, 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 	spin_unlock_irqrestore(&port->lock, 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->xmit.buf, UART_XMIT_SIZE,
1123 				      DMA_TO_DEVICE);
1124 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1125 		reason = "DMA mapping error for TX buffer";
1126 		ret = -EIO;
1127 		goto err_unmap_rx;
1128 	}
1129 
1130 	return 0;
1131 
1132 err_unmap_rx:
1133 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1134 			 dma->rx_size, DMA_FROM_DEVICE);
1135 err_free_rx:
1136 	kfree(dma->rx_buf);
1137 err_release_tx:
1138 	dma_release_channel(dma->tx_chan);
1139 err_release_rx:
1140 	dma_release_channel(dma->rx_chan);
1141 err_warn:
1142 	if (reason)
1143 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1144 	return ret;
1145 }
1146 
1147 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1148 {
1149 	struct s3c24xx_uart_dma	*dma = p->dma;
1150 
1151 	if (dma->rx_chan) {
1152 		dmaengine_terminate_all(dma->rx_chan);
1153 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1154 				 dma->rx_size, DMA_FROM_DEVICE);
1155 		kfree(dma->rx_buf);
1156 		dma_release_channel(dma->rx_chan);
1157 		dma->rx_chan = NULL;
1158 	}
1159 
1160 	if (dma->tx_chan) {
1161 		dmaengine_terminate_all(dma->tx_chan);
1162 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1163 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1164 		dma_release_channel(dma->tx_chan);
1165 		dma->tx_chan = NULL;
1166 	}
1167 }
1168 
1169 static void s3c24xx_serial_shutdown(struct uart_port *port)
1170 {
1171 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1172 
1173 	if (ourport->tx_claimed) {
1174 		free_irq(ourport->tx_irq, ourport);
1175 		ourport->tx_enabled = 0;
1176 		ourport->tx_claimed = 0;
1177 		ourport->tx_mode = 0;
1178 	}
1179 
1180 	if (ourport->rx_claimed) {
1181 		free_irq(ourport->rx_irq, ourport);
1182 		ourport->rx_claimed = 0;
1183 		ourport->rx_enabled = 0;
1184 	}
1185 
1186 	if (ourport->dma)
1187 		s3c24xx_serial_release_dma(ourport);
1188 
1189 	ourport->tx_in_progress = 0;
1190 }
1191 
1192 static void s3c64xx_serial_shutdown(struct uart_port *port)
1193 {
1194 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1195 
1196 	ourport->tx_enabled = 0;
1197 	ourport->tx_mode = 0;
1198 	ourport->rx_enabled = 0;
1199 
1200 	free_irq(port->irq, ourport);
1201 
1202 	wr_regl(port, S3C64XX_UINTP, 0xf);
1203 	wr_regl(port, S3C64XX_UINTM, 0xf);
1204 
1205 	if (ourport->dma)
1206 		s3c24xx_serial_release_dma(ourport);
1207 
1208 	ourport->tx_in_progress = 0;
1209 }
1210 
1211 static void apple_s5l_serial_shutdown(struct uart_port *port)
1212 {
1213 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1214 
1215 	unsigned int ucon;
1216 
1217 	ucon = rd_regl(port, S3C2410_UCON);
1218 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1219 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1220 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1221 	wr_regl(port, S3C2410_UCON, ucon);
1222 
1223 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1224 
1225 	free_irq(port->irq, ourport);
1226 
1227 	ourport->tx_enabled = 0;
1228 	ourport->tx_mode = 0;
1229 	ourport->rx_enabled = 0;
1230 
1231 	if (ourport->dma)
1232 		s3c24xx_serial_release_dma(ourport);
1233 
1234 	ourport->tx_in_progress = 0;
1235 }
1236 
1237 static int s3c24xx_serial_startup(struct uart_port *port)
1238 {
1239 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1240 	int ret;
1241 
1242 	ourport->rx_enabled = 1;
1243 
1244 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
1245 			  s3c24xx_serial_portname(port), ourport);
1246 
1247 	if (ret != 0) {
1248 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1249 		return ret;
1250 	}
1251 
1252 	ourport->rx_claimed = 1;
1253 
1254 	dev_dbg(port->dev, "requesting tx irq...\n");
1255 
1256 	ourport->tx_enabled = 1;
1257 
1258 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
1259 			  s3c24xx_serial_portname(port), ourport);
1260 
1261 	if (ret) {
1262 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1263 		goto err;
1264 	}
1265 
1266 	ourport->tx_claimed = 1;
1267 
1268 	/* the port reset code should have done the correct
1269 	 * register setup for the port controls
1270 	 */
1271 
1272 	return ret;
1273 
1274 err:
1275 	s3c24xx_serial_shutdown(port);
1276 	return ret;
1277 }
1278 
1279 static int s3c64xx_serial_startup(struct uart_port *port)
1280 {
1281 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1282 	unsigned long flags;
1283 	unsigned int ufcon;
1284 	int ret;
1285 
1286 	wr_regl(port, S3C64XX_UINTM, 0xf);
1287 	if (ourport->dma) {
1288 		ret = s3c24xx_serial_request_dma(ourport);
1289 		if (ret < 0) {
1290 			devm_kfree(port->dev, ourport->dma);
1291 			ourport->dma = NULL;
1292 		}
1293 	}
1294 
1295 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1296 			  s3c24xx_serial_portname(port), ourport);
1297 	if (ret) {
1298 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1299 		return ret;
1300 	}
1301 
1302 	/* For compatibility with s3c24xx Soc's */
1303 	ourport->rx_enabled = 1;
1304 	ourport->tx_enabled = 0;
1305 
1306 	spin_lock_irqsave(&port->lock, flags);
1307 
1308 	ufcon = rd_regl(port, S3C2410_UFCON);
1309 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1310 	if (!uart_console(port))
1311 		ufcon |= S3C2410_UFCON_RESETTX;
1312 	wr_regl(port, S3C2410_UFCON, ufcon);
1313 
1314 	enable_rx_pio(ourport);
1315 
1316 	spin_unlock_irqrestore(&port->lock, flags);
1317 
1318 	/* Enable Rx Interrupt */
1319 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1320 
1321 	return ret;
1322 }
1323 
1324 static int apple_s5l_serial_startup(struct uart_port *port)
1325 {
1326 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1327 	unsigned long flags;
1328 	unsigned int ufcon;
1329 	int ret;
1330 
1331 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1332 
1333 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1334 			  s3c24xx_serial_portname(port), ourport);
1335 	if (ret) {
1336 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1337 		return ret;
1338 	}
1339 
1340 	/* For compatibility with s3c24xx Soc's */
1341 	ourport->rx_enabled = 1;
1342 	ourport->tx_enabled = 0;
1343 
1344 	spin_lock_irqsave(&port->lock, flags);
1345 
1346 	ufcon = rd_regl(port, S3C2410_UFCON);
1347 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1348 	if (!uart_console(port))
1349 		ufcon |= S3C2410_UFCON_RESETTX;
1350 	wr_regl(port, S3C2410_UFCON, ufcon);
1351 
1352 	enable_rx_pio(ourport);
1353 
1354 	spin_unlock_irqrestore(&port->lock, flags);
1355 
1356 	/* Enable Rx Interrupt */
1357 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1358 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1359 
1360 	return ret;
1361 }
1362 
1363 /* power power management control */
1364 
1365 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1366 			      unsigned int old)
1367 {
1368 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1369 	int timeout = 10000;
1370 
1371 	ourport->pm_level = level;
1372 
1373 	switch (level) {
1374 	case 3:
1375 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1376 			udelay(100);
1377 
1378 		if (!IS_ERR(ourport->baudclk))
1379 			clk_disable_unprepare(ourport->baudclk);
1380 
1381 		clk_disable_unprepare(ourport->clk);
1382 		break;
1383 
1384 	case 0:
1385 		clk_prepare_enable(ourport->clk);
1386 
1387 		if (!IS_ERR(ourport->baudclk))
1388 			clk_prepare_enable(ourport->baudclk);
1389 		break;
1390 	default:
1391 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1392 	}
1393 }
1394 
1395 /* baud rate calculation
1396  *
1397  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1398  * of different sources, including the peripheral clock ("pclk") and an
1399  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1400  * with a programmable extra divisor.
1401  *
1402  * The following code goes through the clock sources, and calculates the
1403  * baud clocks (and the resultant actual baud rates) and then tries to
1404  * pick the closest one and select that.
1405  *
1406  */
1407 
1408 #define MAX_CLK_NAME_LENGTH 15
1409 
1410 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1411 {
1412 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1413 	unsigned int ucon;
1414 
1415 	if (info->num_clks == 1)
1416 		return 0;
1417 
1418 	ucon = rd_regl(port, S3C2410_UCON);
1419 	ucon &= info->clksel_mask;
1420 	return ucon >> info->clksel_shift;
1421 }
1422 
1423 static void s3c24xx_serial_setsource(struct uart_port *port,
1424 			unsigned int clk_sel)
1425 {
1426 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1427 	unsigned int ucon;
1428 
1429 	if (info->num_clks == 1)
1430 		return;
1431 
1432 	ucon = rd_regl(port, S3C2410_UCON);
1433 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1434 		return;
1435 
1436 	ucon &= ~info->clksel_mask;
1437 	ucon |= clk_sel << info->clksel_shift;
1438 	wr_regl(port, S3C2410_UCON, ucon);
1439 }
1440 
1441 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1442 			unsigned int req_baud, struct clk **best_clk,
1443 			unsigned int *clk_num)
1444 {
1445 	const struct s3c24xx_uart_info *info = ourport->info;
1446 	struct clk *clk;
1447 	unsigned long rate;
1448 	unsigned int cnt, baud, quot, best_quot = 0;
1449 	char clkname[MAX_CLK_NAME_LENGTH];
1450 	int calc_deviation, deviation = (1 << 30) - 1;
1451 
1452 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1453 		/* Keep selected clock if provided */
1454 		if (ourport->cfg->clk_sel &&
1455 			!(ourport->cfg->clk_sel & (1 << cnt)))
1456 			continue;
1457 
1458 		sprintf(clkname, "clk_uart_baud%d", cnt);
1459 		clk = clk_get(ourport->port.dev, clkname);
1460 		if (IS_ERR(clk))
1461 			continue;
1462 
1463 		rate = clk_get_rate(clk);
1464 		if (!rate) {
1465 			dev_err(ourport->port.dev,
1466 				"Failed to get clock rate for %s.\n", clkname);
1467 			clk_put(clk);
1468 			continue;
1469 		}
1470 
1471 		if (ourport->info->has_divslot) {
1472 			unsigned long div = rate / req_baud;
1473 
1474 			/* The UDIVSLOT register on the newer UARTs allows us to
1475 			 * get a divisor adjustment of 1/16th on the baud clock.
1476 			 *
1477 			 * We don't keep the UDIVSLOT value (the 16ths we
1478 			 * calculated by not multiplying the baud by 16) as it
1479 			 * is easy enough to recalculate.
1480 			 */
1481 
1482 			quot = div / 16;
1483 			baud = rate / div;
1484 		} else {
1485 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1486 			baud = rate / (quot * 16);
1487 		}
1488 		quot--;
1489 
1490 		calc_deviation = abs(req_baud - baud);
1491 
1492 		if (calc_deviation < deviation) {
1493 			/*
1494 			 * If we find a better clk, release the previous one, if
1495 			 * any.
1496 			 */
1497 			if (!IS_ERR(*best_clk))
1498 				clk_put(*best_clk);
1499 			*best_clk = clk;
1500 			best_quot = quot;
1501 			*clk_num = cnt;
1502 			deviation = calc_deviation;
1503 		} else {
1504 			clk_put(clk);
1505 		}
1506 	}
1507 
1508 	return best_quot;
1509 }
1510 
1511 /* udivslot_table[]
1512  *
1513  * This table takes the fractional value of the baud divisor and gives
1514  * the recommended setting for the UDIVSLOT register.
1515  */
1516 static const u16 udivslot_table[16] = {
1517 	[0] = 0x0000,
1518 	[1] = 0x0080,
1519 	[2] = 0x0808,
1520 	[3] = 0x0888,
1521 	[4] = 0x2222,
1522 	[5] = 0x4924,
1523 	[6] = 0x4A52,
1524 	[7] = 0x54AA,
1525 	[8] = 0x5555,
1526 	[9] = 0xD555,
1527 	[10] = 0xD5D5,
1528 	[11] = 0xDDD5,
1529 	[12] = 0xDDDD,
1530 	[13] = 0xDFDD,
1531 	[14] = 0xDFDF,
1532 	[15] = 0xFFDF,
1533 };
1534 
1535 static void s3c24xx_serial_set_termios(struct uart_port *port,
1536 				       struct ktermios *termios,
1537 				       const struct ktermios *old)
1538 {
1539 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1540 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1541 	struct clk *clk = ERR_PTR(-EINVAL);
1542 	unsigned long flags;
1543 	unsigned int baud, quot, clk_sel = 0;
1544 	unsigned int ulcon;
1545 	unsigned int umcon;
1546 	unsigned int udivslot = 0;
1547 
1548 	/*
1549 	 * We don't support modem control lines.
1550 	 */
1551 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1552 	termios->c_cflag |= CLOCAL;
1553 
1554 	/*
1555 	 * Ask the core to calculate the divisor for us.
1556 	 */
1557 
1558 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1559 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1560 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1561 		quot = port->custom_divisor;
1562 	if (IS_ERR(clk))
1563 		return;
1564 
1565 	/* check to see if we need  to change clock source */
1566 
1567 	if (ourport->baudclk != clk) {
1568 		clk_prepare_enable(clk);
1569 
1570 		s3c24xx_serial_setsource(port, clk_sel);
1571 
1572 		if (!IS_ERR(ourport->baudclk)) {
1573 			clk_disable_unprepare(ourport->baudclk);
1574 			ourport->baudclk = ERR_PTR(-EINVAL);
1575 		}
1576 
1577 		ourport->baudclk = clk;
1578 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1579 	}
1580 
1581 	if (ourport->info->has_divslot) {
1582 		unsigned int div = ourport->baudclk_rate / baud;
1583 
1584 		if (cfg->has_fracval) {
1585 			udivslot = (div & 15);
1586 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1587 		} else {
1588 			udivslot = udivslot_table[div & 15];
1589 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1590 				udivslot, div & 15);
1591 		}
1592 	}
1593 
1594 	switch (termios->c_cflag & CSIZE) {
1595 	case CS5:
1596 		dev_dbg(port->dev, "config: 5bits/char\n");
1597 		ulcon = S3C2410_LCON_CS5;
1598 		break;
1599 	case CS6:
1600 		dev_dbg(port->dev, "config: 6bits/char\n");
1601 		ulcon = S3C2410_LCON_CS6;
1602 		break;
1603 	case CS7:
1604 		dev_dbg(port->dev, "config: 7bits/char\n");
1605 		ulcon = S3C2410_LCON_CS7;
1606 		break;
1607 	case CS8:
1608 	default:
1609 		dev_dbg(port->dev, "config: 8bits/char\n");
1610 		ulcon = S3C2410_LCON_CS8;
1611 		break;
1612 	}
1613 
1614 	/* preserve original lcon IR settings */
1615 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1616 
1617 	if (termios->c_cflag & CSTOPB)
1618 		ulcon |= S3C2410_LCON_STOPB;
1619 
1620 	if (termios->c_cflag & PARENB) {
1621 		if (termios->c_cflag & PARODD)
1622 			ulcon |= S3C2410_LCON_PODD;
1623 		else
1624 			ulcon |= S3C2410_LCON_PEVEN;
1625 	} else {
1626 		ulcon |= S3C2410_LCON_PNONE;
1627 	}
1628 
1629 	spin_lock_irqsave(&port->lock, flags);
1630 
1631 	dev_dbg(port->dev,
1632 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1633 		ulcon, quot, udivslot);
1634 
1635 	wr_regl(port, S3C2410_ULCON, ulcon);
1636 	wr_regl(port, S3C2410_UBRDIV, quot);
1637 
1638 	port->status &= ~UPSTAT_AUTOCTS;
1639 
1640 	umcon = rd_regl(port, S3C2410_UMCON);
1641 	if (termios->c_cflag & CRTSCTS) {
1642 		umcon |= S3C2410_UMCOM_AFC;
1643 		/* Disable RTS when RX FIFO contains 63 bytes */
1644 		umcon &= ~S3C2412_UMCON_AFC_8;
1645 		port->status = UPSTAT_AUTOCTS;
1646 	} else {
1647 		umcon &= ~S3C2410_UMCOM_AFC;
1648 	}
1649 	wr_regl(port, S3C2410_UMCON, umcon);
1650 
1651 	if (ourport->info->has_divslot)
1652 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1653 
1654 	dev_dbg(port->dev,
1655 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1656 		rd_regl(port, S3C2410_ULCON),
1657 		rd_regl(port, S3C2410_UCON),
1658 		rd_regl(port, S3C2410_UFCON));
1659 
1660 	/*
1661 	 * Update the per-port timeout.
1662 	 */
1663 	uart_update_timeout(port, termios->c_cflag, baud);
1664 
1665 	/*
1666 	 * Which character status flags are we interested in?
1667 	 */
1668 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1669 	if (termios->c_iflag & INPCK)
1670 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1671 			S3C2410_UERSTAT_PARITY;
1672 	/*
1673 	 * Which character status flags should we ignore?
1674 	 */
1675 	port->ignore_status_mask = 0;
1676 	if (termios->c_iflag & IGNPAR)
1677 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1678 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1679 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1680 
1681 	/*
1682 	 * Ignore all characters if CREAD is not set.
1683 	 */
1684 	if ((termios->c_cflag & CREAD) == 0)
1685 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1686 
1687 	spin_unlock_irqrestore(&port->lock, flags);
1688 }
1689 
1690 static const char *s3c24xx_serial_type(struct uart_port *port)
1691 {
1692 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
1693 
1694 	switch (ourport->info->type) {
1695 	case TYPE_S3C24XX:
1696 		return "S3C24XX";
1697 	case TYPE_S3C6400:
1698 		return "S3C6400/10";
1699 	case TYPE_APPLE_S5L:
1700 		return "APPLE S5L";
1701 	default:
1702 		return NULL;
1703 	}
1704 }
1705 
1706 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1707 {
1708 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1709 
1710 	if (flags & UART_CONFIG_TYPE)
1711 		port->type = info->port_type;
1712 }
1713 
1714 /*
1715  * verify the new serial_struct (for TIOCSSERIAL).
1716  */
1717 static int
1718 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1719 {
1720 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1721 
1722 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1723 		return -EINVAL;
1724 
1725 	return 0;
1726 }
1727 
1728 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1729 
1730 static struct console s3c24xx_serial_console;
1731 
1732 static void __init s3c24xx_serial_register_console(void)
1733 {
1734 	register_console(&s3c24xx_serial_console);
1735 }
1736 
1737 static void s3c24xx_serial_unregister_console(void)
1738 {
1739 	if (console_is_registered(&s3c24xx_serial_console))
1740 		unregister_console(&s3c24xx_serial_console);
1741 }
1742 
1743 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1744 #else
1745 static inline void s3c24xx_serial_register_console(void) { }
1746 static inline void s3c24xx_serial_unregister_console(void) { }
1747 #define S3C24XX_SERIAL_CONSOLE NULL
1748 #endif
1749 
1750 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1751 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1752 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1753 			 unsigned char c);
1754 #endif
1755 
1756 static const struct uart_ops s3c24xx_serial_ops = {
1757 	.pm		= s3c24xx_serial_pm,
1758 	.tx_empty	= s3c24xx_serial_tx_empty,
1759 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1760 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1761 	.stop_tx	= s3c24xx_serial_stop_tx,
1762 	.start_tx	= s3c24xx_serial_start_tx,
1763 	.stop_rx	= s3c24xx_serial_stop_rx,
1764 	.break_ctl	= s3c24xx_serial_break_ctl,
1765 	.startup	= s3c24xx_serial_startup,
1766 	.shutdown	= s3c24xx_serial_shutdown,
1767 	.set_termios	= s3c24xx_serial_set_termios,
1768 	.type		= s3c24xx_serial_type,
1769 	.config_port	= s3c24xx_serial_config_port,
1770 	.verify_port	= s3c24xx_serial_verify_port,
1771 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1772 	.poll_get_char = s3c24xx_serial_get_poll_char,
1773 	.poll_put_char = s3c24xx_serial_put_poll_char,
1774 #endif
1775 };
1776 
1777 static const struct uart_ops s3c64xx_serial_ops = {
1778 	.pm		= s3c24xx_serial_pm,
1779 	.tx_empty	= s3c24xx_serial_tx_empty,
1780 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1781 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1782 	.stop_tx	= s3c24xx_serial_stop_tx,
1783 	.start_tx	= s3c24xx_serial_start_tx,
1784 	.stop_rx	= s3c24xx_serial_stop_rx,
1785 	.break_ctl	= s3c24xx_serial_break_ctl,
1786 	.startup	= s3c64xx_serial_startup,
1787 	.shutdown	= s3c64xx_serial_shutdown,
1788 	.set_termios	= s3c24xx_serial_set_termios,
1789 	.type		= s3c24xx_serial_type,
1790 	.config_port	= s3c24xx_serial_config_port,
1791 	.verify_port	= s3c24xx_serial_verify_port,
1792 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1793 	.poll_get_char = s3c24xx_serial_get_poll_char,
1794 	.poll_put_char = s3c24xx_serial_put_poll_char,
1795 #endif
1796 };
1797 
1798 static const struct uart_ops apple_s5l_serial_ops = {
1799 	.pm		= s3c24xx_serial_pm,
1800 	.tx_empty	= s3c24xx_serial_tx_empty,
1801 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1802 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1803 	.stop_tx	= s3c24xx_serial_stop_tx,
1804 	.start_tx	= s3c24xx_serial_start_tx,
1805 	.stop_rx	= s3c24xx_serial_stop_rx,
1806 	.break_ctl	= s3c24xx_serial_break_ctl,
1807 	.startup	= apple_s5l_serial_startup,
1808 	.shutdown	= apple_s5l_serial_shutdown,
1809 	.set_termios	= s3c24xx_serial_set_termios,
1810 	.type		= s3c24xx_serial_type,
1811 	.config_port	= s3c24xx_serial_config_port,
1812 	.verify_port	= s3c24xx_serial_verify_port,
1813 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1814 	.poll_get_char = s3c24xx_serial_get_poll_char,
1815 	.poll_put_char = s3c24xx_serial_put_poll_char,
1816 #endif
1817 };
1818 
1819 static struct uart_driver s3c24xx_uart_drv = {
1820 	.owner		= THIS_MODULE,
1821 	.driver_name	= "s3c2410_serial",
1822 	.nr		= UART_NR,
1823 	.cons		= S3C24XX_SERIAL_CONSOLE,
1824 	.dev_name	= S3C24XX_SERIAL_NAME,
1825 	.major		= S3C24XX_SERIAL_MAJOR,
1826 	.minor		= S3C24XX_SERIAL_MINOR,
1827 };
1828 
1829 static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
1830 
1831 static void s3c24xx_serial_init_port_default(int index) {
1832 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1833 
1834 	spin_lock_init(&port->lock);
1835 
1836 	port->iotype = UPIO_MEM;
1837 	port->uartclk = 0;
1838 	port->fifosize = 16;
1839 	port->ops = &s3c24xx_serial_ops;
1840 	port->flags = UPF_BOOT_AUTOCONF;
1841 	port->line = index;
1842 }
1843 
1844 /* s3c24xx_serial_resetport
1845  *
1846  * reset the fifos and other the settings.
1847  */
1848 
1849 static void s3c24xx_serial_resetport(struct uart_port *port,
1850 				     const struct s3c2410_uartcfg *cfg)
1851 {
1852 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1853 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1854 
1855 	ucon &= (info->clksel_mask | info->ucon_mask);
1856 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1857 
1858 	/* reset both fifos */
1859 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1860 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1861 
1862 	/* some delay is required after fifo reset */
1863 	udelay(1);
1864 }
1865 
1866 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1867 {
1868 	struct device *dev = ourport->port.dev;
1869 	const struct s3c24xx_uart_info *info = ourport->info;
1870 	char clk_name[MAX_CLK_NAME_LENGTH];
1871 	unsigned int clk_sel;
1872 	struct clk *clk;
1873 	int clk_num;
1874 	int ret;
1875 
1876 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1877 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1878 		if (!(clk_sel & (1 << clk_num)))
1879 			continue;
1880 
1881 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1882 		clk = clk_get(dev, clk_name);
1883 		if (IS_ERR(clk))
1884 			continue;
1885 
1886 		ret = clk_prepare_enable(clk);
1887 		if (ret) {
1888 			clk_put(clk);
1889 			continue;
1890 		}
1891 
1892 		ourport->baudclk = clk;
1893 		ourport->baudclk_rate = clk_get_rate(clk);
1894 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1895 
1896 		return 0;
1897 	}
1898 
1899 	return -EINVAL;
1900 }
1901 
1902 /* s3c24xx_serial_init_port
1903  *
1904  * initialise a single serial port from the platform device given
1905  */
1906 
1907 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1908 				    struct platform_device *platdev)
1909 {
1910 	struct uart_port *port = &ourport->port;
1911 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1912 	struct resource *res;
1913 	int ret;
1914 
1915 	if (platdev == NULL)
1916 		return -ENODEV;
1917 
1918 	if (port->mapbase != 0)
1919 		return -EINVAL;
1920 
1921 	/* setup info for port */
1922 	port->dev	= &platdev->dev;
1923 
1924 	port->uartclk = 1;
1925 
1926 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1927 		dev_dbg(port->dev, "enabling flow control\n");
1928 		port->flags |= UPF_CONS_FLOW;
1929 	}
1930 
1931 	/* sort our the physical and virtual addresses for each UART */
1932 
1933 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1934 	if (res == NULL) {
1935 		dev_err(port->dev, "failed to find memory resource for uart\n");
1936 		return -EINVAL;
1937 	}
1938 
1939 	dev_dbg(port->dev, "resource %pR)\n", res);
1940 
1941 	port->membase = devm_ioremap_resource(port->dev, res);
1942 	if (IS_ERR(port->membase)) {
1943 		dev_err(port->dev, "failed to remap controller address\n");
1944 		return -EBUSY;
1945 	}
1946 
1947 	port->mapbase = res->start;
1948 	ret = platform_get_irq(platdev, 0);
1949 	if (ret < 0) {
1950 		port->irq = 0;
1951 	} else {
1952 		port->irq = ret;
1953 		ourport->rx_irq = ret;
1954 		ourport->tx_irq = ret + 1;
1955 	}
1956 
1957 	switch (ourport->info->type) {
1958 	case TYPE_S3C24XX:
1959 		ret = platform_get_irq(platdev, 1);
1960 		if (ret > 0)
1961 			ourport->tx_irq = ret;
1962 		break;
1963 	default:
1964 		break;
1965 	}
1966 
1967 	/*
1968 	 * DMA is currently supported only on DT platforms, if DMA properties
1969 	 * are specified.
1970 	 */
1971 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1972 						     "dmas", NULL)) {
1973 		ourport->dma = devm_kzalloc(port->dev,
1974 					    sizeof(*ourport->dma),
1975 					    GFP_KERNEL);
1976 		if (!ourport->dma) {
1977 			ret = -ENOMEM;
1978 			goto err;
1979 		}
1980 	}
1981 
1982 	ourport->clk	= clk_get(&platdev->dev, "uart");
1983 	if (IS_ERR(ourport->clk)) {
1984 		pr_err("%s: Controller clock not found\n",
1985 				dev_name(&platdev->dev));
1986 		ret = PTR_ERR(ourport->clk);
1987 		goto err;
1988 	}
1989 
1990 	ret = clk_prepare_enable(ourport->clk);
1991 	if (ret) {
1992 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1993 		clk_put(ourport->clk);
1994 		goto err;
1995 	}
1996 
1997 	ret = s3c24xx_serial_enable_baudclk(ourport);
1998 	if (ret)
1999 		pr_warn("uart: failed to enable baudclk\n");
2000 
2001 	/* Keep all interrupts masked and cleared */
2002 	switch (ourport->info->type) {
2003 	case TYPE_S3C6400:
2004 		wr_regl(port, S3C64XX_UINTM, 0xf);
2005 		wr_regl(port, S3C64XX_UINTP, 0xf);
2006 		wr_regl(port, S3C64XX_UINTSP, 0xf);
2007 		break;
2008 	case TYPE_APPLE_S5L: {
2009 		unsigned int ucon;
2010 
2011 		ucon = rd_regl(port, S3C2410_UCON);
2012 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2013 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2014 			APPLE_S5L_UCON_RXTO_ENA_MSK);
2015 		wr_regl(port, S3C2410_UCON, ucon);
2016 
2017 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
2018 		break;
2019 	}
2020 	default:
2021 		break;
2022 	}
2023 
2024 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
2025 		&port->mapbase, port->membase, port->irq,
2026 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
2027 
2028 	/* reset the fifos (and setup the uart) */
2029 	s3c24xx_serial_resetport(port, cfg);
2030 
2031 	return 0;
2032 
2033 err:
2034 	port->mapbase = 0;
2035 	return ret;
2036 }
2037 
2038 /* Device driver serial port probe */
2039 
2040 static int probe_index;
2041 
2042 static inline const struct s3c24xx_serial_drv_data *
2043 s3c24xx_get_driver_data(struct platform_device *pdev)
2044 {
2045 	if (dev_of_node(&pdev->dev))
2046 		return of_device_get_match_data(&pdev->dev);
2047 
2048 	return (struct s3c24xx_serial_drv_data *)
2049 			platform_get_device_id(pdev)->driver_data;
2050 }
2051 
2052 static int s3c24xx_serial_probe(struct platform_device *pdev)
2053 {
2054 	struct device_node *np = pdev->dev.of_node;
2055 	struct s3c24xx_uart_port *ourport;
2056 	int index = probe_index;
2057 	int ret, prop = 0;
2058 
2059 	if (np) {
2060 		ret = of_alias_get_id(np, "serial");
2061 		if (ret >= 0)
2062 			index = ret;
2063 	}
2064 
2065 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2066 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2067 		return -EINVAL;
2068 	}
2069 	ourport = &s3c24xx_serial_ports[index];
2070 
2071 	s3c24xx_serial_init_port_default(index);
2072 
2073 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2074 	if (!ourport->drv_data) {
2075 		dev_err(&pdev->dev, "could not find driver data\n");
2076 		return -ENODEV;
2077 	}
2078 
2079 	ourport->baudclk = ERR_PTR(-EINVAL);
2080 	ourport->info = &ourport->drv_data->info;
2081 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2082 			dev_get_platdata(&pdev->dev) :
2083 			&ourport->drv_data->def_cfg;
2084 
2085 	switch (ourport->info->type) {
2086 	case TYPE_S3C24XX:
2087 		ourport->port.ops = &s3c24xx_serial_ops;
2088 		break;
2089 	case TYPE_S3C6400:
2090 		ourport->port.ops = &s3c64xx_serial_ops;
2091 		break;
2092 	case TYPE_APPLE_S5L:
2093 		ourport->port.ops = &apple_s5l_serial_ops;
2094 		break;
2095 	}
2096 
2097 	if (np) {
2098 		of_property_read_u32(np,
2099 			"samsung,uart-fifosize", &ourport->port.fifosize);
2100 
2101 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2102 			switch (prop) {
2103 			case 1:
2104 				ourport->port.iotype = UPIO_MEM;
2105 				break;
2106 			case 4:
2107 				ourport->port.iotype = UPIO_MEM32;
2108 				break;
2109 			default:
2110 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2111 						prop);
2112 				return -EINVAL;
2113 			}
2114 		}
2115 	}
2116 
2117 	if (ourport->drv_data->fifosize[index])
2118 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2119 	else if (ourport->info->fifosize)
2120 		ourport->port.fifosize = ourport->info->fifosize;
2121 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2122 
2123 	/*
2124 	 * DMA transfers must be aligned at least to cache line size,
2125 	 * so find minimal transfer size suitable for DMA mode
2126 	 */
2127 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2128 				    dma_get_cache_alignment());
2129 
2130 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2131 
2132 	ret = s3c24xx_serial_init_port(ourport, pdev);
2133 	if (ret < 0)
2134 		return ret;
2135 
2136 	if (!s3c24xx_uart_drv.state) {
2137 		ret = uart_register_driver(&s3c24xx_uart_drv);
2138 		if (ret < 0) {
2139 			pr_err("Failed to register Samsung UART driver\n");
2140 			return ret;
2141 		}
2142 	}
2143 
2144 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2145 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2146 	platform_set_drvdata(pdev, &ourport->port);
2147 
2148 	/*
2149 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2150 	 * so that a potential re-enablement through the pm-callback overlaps
2151 	 * and keeps the clock enabled in this case.
2152 	 */
2153 	clk_disable_unprepare(ourport->clk);
2154 	if (!IS_ERR(ourport->baudclk))
2155 		clk_disable_unprepare(ourport->baudclk);
2156 
2157 	probe_index++;
2158 
2159 	return 0;
2160 }
2161 
2162 static int s3c24xx_serial_remove(struct platform_device *dev)
2163 {
2164 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2165 
2166 	if (port) {
2167 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2168 	}
2169 
2170 	uart_unregister_driver(&s3c24xx_uart_drv);
2171 
2172 	return 0;
2173 }
2174 
2175 /* UART power management code */
2176 #ifdef CONFIG_PM_SLEEP
2177 static int s3c24xx_serial_suspend(struct device *dev)
2178 {
2179 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2180 
2181 	if (port)
2182 		uart_suspend_port(&s3c24xx_uart_drv, port);
2183 
2184 	return 0;
2185 }
2186 
2187 static int s3c24xx_serial_resume(struct device *dev)
2188 {
2189 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2190 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2191 
2192 	if (port) {
2193 		clk_prepare_enable(ourport->clk);
2194 		if (!IS_ERR(ourport->baudclk))
2195 			clk_prepare_enable(ourport->baudclk);
2196 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2197 		if (!IS_ERR(ourport->baudclk))
2198 			clk_disable_unprepare(ourport->baudclk);
2199 		clk_disable_unprepare(ourport->clk);
2200 
2201 		uart_resume_port(&s3c24xx_uart_drv, port);
2202 	}
2203 
2204 	return 0;
2205 }
2206 
2207 static int s3c24xx_serial_resume_noirq(struct device *dev)
2208 {
2209 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2210 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2211 
2212 	if (port) {
2213 		/* restore IRQ mask */
2214 		switch (ourport->info->type) {
2215 		case TYPE_S3C6400: {
2216 			unsigned int uintm = 0xf;
2217 
2218 			if (ourport->tx_enabled)
2219 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2220 			if (ourport->rx_enabled)
2221 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2222 			clk_prepare_enable(ourport->clk);
2223 			if (!IS_ERR(ourport->baudclk))
2224 				clk_prepare_enable(ourport->baudclk);
2225 			wr_regl(port, S3C64XX_UINTM, uintm);
2226 			if (!IS_ERR(ourport->baudclk))
2227 				clk_disable_unprepare(ourport->baudclk);
2228 			clk_disable_unprepare(ourport->clk);
2229 			break;
2230 		}
2231 		case TYPE_APPLE_S5L: {
2232 			unsigned int ucon;
2233 			int ret;
2234 
2235 			ret = clk_prepare_enable(ourport->clk);
2236 			if (ret) {
2237 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2238 				return ret;
2239 			}
2240 			if (!IS_ERR(ourport->baudclk)) {
2241 				ret = clk_prepare_enable(ourport->baudclk);
2242 				if (ret) {
2243 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2244 					clk_disable_unprepare(ourport->clk);
2245 					return ret;
2246 				}
2247 			}
2248 
2249 			ucon = rd_regl(port, S3C2410_UCON);
2250 
2251 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2252 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2253 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2254 
2255 			if (ourport->tx_enabled)
2256 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2257 			if (ourport->rx_enabled)
2258 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2259 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2260 
2261 			wr_regl(port, S3C2410_UCON, ucon);
2262 
2263 			if (!IS_ERR(ourport->baudclk))
2264 				clk_disable_unprepare(ourport->baudclk);
2265 			clk_disable_unprepare(ourport->clk);
2266 			break;
2267 		}
2268 		default:
2269 			break;
2270 		}
2271 	}
2272 
2273 	return 0;
2274 }
2275 
2276 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2277 	SET_SYSTEM_SLEEP_PM_OPS(s3c24xx_serial_suspend, s3c24xx_serial_resume)
2278 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, s3c24xx_serial_resume_noirq)
2279 };
2280 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2281 
2282 #else /* !CONFIG_PM_SLEEP */
2283 
2284 #define SERIAL_SAMSUNG_PM_OPS	NULL
2285 #endif /* CONFIG_PM_SLEEP */
2286 
2287 /* Console code */
2288 
2289 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2290 
2291 static struct uart_port *cons_uart;
2292 
2293 static int
2294 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2295 {
2296 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2297 	unsigned long ufstat, utrstat;
2298 
2299 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2300 		/* fifo mode - check amount of data in fifo registers... */
2301 
2302 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2303 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2304 	}
2305 
2306 	/* in non-fifo mode, we go and use the tx buffer empty */
2307 
2308 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2309 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2310 }
2311 
2312 static bool
2313 s3c24xx_port_configured(unsigned int ucon)
2314 {
2315 	/* consider the serial port configured if the tx/rx mode set */
2316 	return (ucon & 0xf) != 0;
2317 }
2318 
2319 #ifdef CONFIG_CONSOLE_POLL
2320 /*
2321  * Console polling routines for writing and reading from the uart while
2322  * in an interrupt or debug context.
2323  */
2324 
2325 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2326 {
2327 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2328 	unsigned int ufstat;
2329 
2330 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2331 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2332 		return NO_POLL_CHAR;
2333 
2334 	return rd_reg(port, S3C2410_URXH);
2335 }
2336 
2337 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2338 		unsigned char c)
2339 {
2340 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2341 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2342 
2343 	/* not possible to xmit on unconfigured port */
2344 	if (!s3c24xx_port_configured(ucon))
2345 		return;
2346 
2347 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2348 		cpu_relax();
2349 	wr_reg(port, S3C2410_UTXH, c);
2350 }
2351 
2352 #endif /* CONFIG_CONSOLE_POLL */
2353 
2354 static void
2355 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2356 {
2357 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2358 
2359 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2360 		cpu_relax();
2361 	wr_reg(port, S3C2410_UTXH, ch);
2362 }
2363 
2364 static void
2365 s3c24xx_serial_console_write(struct console *co, const char *s,
2366 			     unsigned int count)
2367 {
2368 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2369 	unsigned long flags;
2370 	bool locked = true;
2371 
2372 	/* not possible to xmit on unconfigured port */
2373 	if (!s3c24xx_port_configured(ucon))
2374 		return;
2375 
2376 	if (cons_uart->sysrq)
2377 		locked = false;
2378 	else if (oops_in_progress)
2379 		locked = spin_trylock_irqsave(&cons_uart->lock, flags);
2380 	else
2381 		spin_lock_irqsave(&cons_uart->lock, flags);
2382 
2383 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2384 
2385 	if (locked)
2386 		spin_unlock_irqrestore(&cons_uart->lock, flags);
2387 }
2388 
2389 /* Shouldn't be __init, as it can be instantiated from other module */
2390 static void
2391 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2392 			   int *parity, int *bits)
2393 {
2394 	struct clk *clk;
2395 	unsigned int ulcon;
2396 	unsigned int ucon;
2397 	unsigned int ubrdiv;
2398 	unsigned long rate;
2399 	unsigned int clk_sel;
2400 	char clk_name[MAX_CLK_NAME_LENGTH];
2401 
2402 	ulcon  = rd_regl(port, S3C2410_ULCON);
2403 	ucon   = rd_regl(port, S3C2410_UCON);
2404 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2405 
2406 	if (s3c24xx_port_configured(ucon)) {
2407 		switch (ulcon & S3C2410_LCON_CSMASK) {
2408 		case S3C2410_LCON_CS5:
2409 			*bits = 5;
2410 			break;
2411 		case S3C2410_LCON_CS6:
2412 			*bits = 6;
2413 			break;
2414 		case S3C2410_LCON_CS7:
2415 			*bits = 7;
2416 			break;
2417 		case S3C2410_LCON_CS8:
2418 		default:
2419 			*bits = 8;
2420 			break;
2421 		}
2422 
2423 		switch (ulcon & S3C2410_LCON_PMASK) {
2424 		case S3C2410_LCON_PEVEN:
2425 			*parity = 'e';
2426 			break;
2427 
2428 		case S3C2410_LCON_PODD:
2429 			*parity = 'o';
2430 			break;
2431 
2432 		case S3C2410_LCON_PNONE:
2433 		default:
2434 			*parity = 'n';
2435 		}
2436 
2437 		/* now calculate the baud rate */
2438 
2439 		clk_sel = s3c24xx_serial_getsource(port);
2440 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2441 
2442 		clk = clk_get(port->dev, clk_name);
2443 		if (!IS_ERR(clk))
2444 			rate = clk_get_rate(clk);
2445 		else
2446 			rate = 1;
2447 
2448 		*baud = rate / (16 * (ubrdiv + 1));
2449 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2450 	}
2451 }
2452 
2453 /* Shouldn't be __init, as it can be instantiated from other module */
2454 static int
2455 s3c24xx_serial_console_setup(struct console *co, char *options)
2456 {
2457 	struct uart_port *port;
2458 	int baud = 9600;
2459 	int bits = 8;
2460 	int parity = 'n';
2461 	int flow = 'n';
2462 
2463 	/* is this a valid port */
2464 
2465 	if (co->index == -1 || co->index >= UART_NR)
2466 		co->index = 0;
2467 
2468 	port = &s3c24xx_serial_ports[co->index].port;
2469 
2470 	/* is the port configured? */
2471 
2472 	if (port->mapbase == 0x0)
2473 		return -ENODEV;
2474 
2475 	cons_uart = port;
2476 
2477 	/*
2478 	 * Check whether an invalid uart number has been specified, and
2479 	 * if so, search for the first available port that does have
2480 	 * console support.
2481 	 */
2482 	if (options)
2483 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2484 	else
2485 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2486 
2487 	dev_dbg(port->dev, "baud %d\n", baud);
2488 
2489 	return uart_set_options(port, co, baud, parity, bits, flow);
2490 }
2491 
2492 static struct console s3c24xx_serial_console = {
2493 	.name		= S3C24XX_SERIAL_NAME,
2494 	.device		= uart_console_device,
2495 	.flags		= CON_PRINTBUFFER,
2496 	.index		= -1,
2497 	.write		= s3c24xx_serial_console_write,
2498 	.setup		= s3c24xx_serial_console_setup,
2499 	.data		= &s3c24xx_uart_drv,
2500 };
2501 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2502 
2503 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2504 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2505 	.info = {
2506 		.name		= "Samsung S3C6400 UART",
2507 		.type		= TYPE_S3C6400,
2508 		.port_type	= PORT_S3C6400,
2509 		.fifosize	= 64,
2510 		.has_divslot	= 1,
2511 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2512 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2513 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2514 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2515 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2516 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2517 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2518 		.num_clks	= 4,
2519 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2520 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2521 	},
2522 	.def_cfg = {
2523 		.ucon		= S3C2410_UCON_DEFAULT,
2524 		.ufcon		= S3C2410_UFCON_DEFAULT,
2525 	},
2526 };
2527 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2528 #else
2529 #define S3C6400_SERIAL_DRV_DATA NULL
2530 #endif
2531 
2532 #ifdef CONFIG_CPU_S5PV210
2533 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2534 	.info = {
2535 		.name		= "Samsung S5PV210 UART",
2536 		.type		= TYPE_S3C6400,
2537 		.port_type	= PORT_S3C6400,
2538 		.has_divslot	= 1,
2539 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2540 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2541 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2542 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2543 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2544 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2545 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2546 		.num_clks	= 2,
2547 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2548 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2549 	},
2550 	.def_cfg = {
2551 		.ucon		= S5PV210_UCON_DEFAULT,
2552 		.ufcon		= S5PV210_UFCON_DEFAULT,
2553 	},
2554 	.fifosize = { 256, 64, 16, 16 },
2555 };
2556 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2557 #else
2558 #define S5PV210_SERIAL_DRV_DATA	NULL
2559 #endif
2560 
2561 #if defined(CONFIG_ARCH_EXYNOS)
2562 #define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
2563 	.info = {						\
2564 		.name		= "Samsung Exynos UART",	\
2565 		.type		= TYPE_S3C6400,			\
2566 		.port_type	= PORT_S3C6400,			\
2567 		.has_divslot	= 1,				\
2568 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2569 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2570 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2571 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2572 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2573 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2574 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2575 		.num_clks	= 1,				\
2576 		.clksel_mask	= 0,				\
2577 		.clksel_shift	= 0,				\
2578 	},							\
2579 	.def_cfg = {						\
2580 		.ucon		= S5PV210_UCON_DEFAULT,		\
2581 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2582 		.has_fracval	= 1,				\
2583 	}							\
2584 
2585 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2586 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2587 	.fifosize = { 256, 64, 16, 16 },
2588 };
2589 
2590 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2591 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2592 	.fifosize = { 64, 256, 16, 256 },
2593 };
2594 
2595 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2596 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2597 	.fifosize = { 256, 64, 64, 64 },
2598 };
2599 
2600 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2601 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2602 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2603 
2604 #else
2605 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2606 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2607 #define EXYNOS850_SERIAL_DRV_DATA NULL
2608 #endif
2609 
2610 #ifdef CONFIG_ARCH_APPLE
2611 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2612 	.info = {
2613 		.name		= "Apple S5L UART",
2614 		.type		= TYPE_APPLE_S5L,
2615 		.port_type	= PORT_8250,
2616 		.fifosize	= 16,
2617 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2618 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2619 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2620 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2621 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2622 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2623 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2624 		.num_clks	= 1,
2625 		.clksel_mask	= 0,
2626 		.clksel_shift	= 0,
2627 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2628 	},
2629 	.def_cfg = {
2630 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2631 		.ufcon		= S3C2410_UFCON_DEFAULT,
2632 	},
2633 };
2634 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2635 #else
2636 #define S5L_SERIAL_DRV_DATA NULL
2637 #endif
2638 
2639 #if defined(CONFIG_ARCH_ARTPEC)
2640 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2641 	.info = {
2642 		.name		= "Axis ARTPEC-8 UART",
2643 		.type		= TYPE_S3C6400,
2644 		.port_type	= PORT_S3C6400,
2645 		.fifosize	= 64,
2646 		.has_divslot	= 1,
2647 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2648 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2649 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2650 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2651 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2652 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2653 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2654 		.num_clks	= 1,
2655 		.clksel_mask	= 0,
2656 		.clksel_shift	= 0,
2657 	},
2658 	.def_cfg = {
2659 		.ucon		= S5PV210_UCON_DEFAULT,
2660 		.ufcon		= S5PV210_UFCON_DEFAULT,
2661 		.has_fracval	= 1,
2662 	}
2663 };
2664 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2665 #else
2666 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2667 #endif
2668 
2669 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2670 	{
2671 		.name		= "s3c6400-uart",
2672 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2673 	}, {
2674 		.name		= "s5pv210-uart",
2675 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2676 	}, {
2677 		.name		= "exynos4210-uart",
2678 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2679 	}, {
2680 		.name		= "exynos5433-uart",
2681 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2682 	}, {
2683 		.name		= "s5l-uart",
2684 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2685 	}, {
2686 		.name		= "exynos850-uart",
2687 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2688 	}, {
2689 		.name		= "artpec8-uart",
2690 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2691 	},
2692 	{ },
2693 };
2694 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2695 
2696 #ifdef CONFIG_OF
2697 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2698 	{ .compatible = "samsung,s3c6400-uart",
2699 		.data = S3C6400_SERIAL_DRV_DATA },
2700 	{ .compatible = "samsung,s5pv210-uart",
2701 		.data = S5PV210_SERIAL_DRV_DATA },
2702 	{ .compatible = "samsung,exynos4210-uart",
2703 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2704 	{ .compatible = "samsung,exynos5433-uart",
2705 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2706 	{ .compatible = "apple,s5l-uart",
2707 		.data = S5L_SERIAL_DRV_DATA },
2708 	{ .compatible = "samsung,exynos850-uart",
2709 		.data = EXYNOS850_SERIAL_DRV_DATA },
2710 	{ .compatible = "axis,artpec8-uart",
2711 		.data = ARTPEC8_SERIAL_DRV_DATA },
2712 	{},
2713 };
2714 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2715 #endif
2716 
2717 static struct platform_driver samsung_serial_driver = {
2718 	.probe		= s3c24xx_serial_probe,
2719 	.remove		= s3c24xx_serial_remove,
2720 	.id_table	= s3c24xx_serial_driver_ids,
2721 	.driver		= {
2722 		.name	= "samsung-uart",
2723 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2724 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2725 	},
2726 };
2727 
2728 static int __init samsung_serial_init(void)
2729 {
2730 	int ret;
2731 
2732 	s3c24xx_serial_register_console();
2733 
2734 	ret = platform_driver_register(&samsung_serial_driver);
2735 	if (ret) {
2736 		s3c24xx_serial_unregister_console();
2737 		return ret;
2738 	}
2739 
2740 	return 0;
2741 }
2742 
2743 static void __exit samsung_serial_exit(void)
2744 {
2745 	platform_driver_unregister(&samsung_serial_driver);
2746 	s3c24xx_serial_unregister_console();
2747 }
2748 
2749 module_init(samsung_serial_init);
2750 module_exit(samsung_serial_exit);
2751 
2752 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2753 /*
2754  * Early console.
2755  */
2756 
2757 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2758 {
2759 	switch (port->iotype) {
2760 	case UPIO_MEM:
2761 		writeb(val, portaddr(port, reg));
2762 		break;
2763 	case UPIO_MEM32:
2764 		writel(val, portaddr(port, reg));
2765 		break;
2766 	}
2767 }
2768 
2769 struct samsung_early_console_data {
2770 	u32 txfull_mask;
2771 	u32 rxfifo_mask;
2772 };
2773 
2774 static void samsung_early_busyuart(const struct uart_port *port)
2775 {
2776 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2777 		;
2778 }
2779 
2780 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2781 {
2782 	const struct samsung_early_console_data *data = port->private_data;
2783 
2784 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2785 		;
2786 }
2787 
2788 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2789 {
2790 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2791 		samsung_early_busyuart_fifo(port);
2792 	else
2793 		samsung_early_busyuart(port);
2794 
2795 	wr_reg_barrier(port, S3C2410_UTXH, c);
2796 }
2797 
2798 static void samsung_early_write(struct console *con, const char *s,
2799 				unsigned int n)
2800 {
2801 	struct earlycon_device *dev = con->data;
2802 
2803 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2804 }
2805 
2806 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2807 {
2808 	struct earlycon_device *dev = con->data;
2809 	const struct samsung_early_console_data *data = dev->port.private_data;
2810 	int ch, ufstat, num_read = 0;
2811 
2812 	while (num_read < n) {
2813 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
2814 		if (!(ufstat & data->rxfifo_mask))
2815 			break;
2816 		ch = rd_reg(&dev->port, S3C2410_URXH);
2817 		if (ch == NO_POLL_CHAR)
2818 			break;
2819 
2820 		s[num_read++] = ch;
2821 	}
2822 
2823 	return num_read;
2824 }
2825 
2826 static int __init samsung_early_console_setup(struct earlycon_device *device,
2827 					      const char *opt)
2828 {
2829 	if (!device->port.membase)
2830 		return -ENODEV;
2831 
2832 	device->con->write = samsung_early_write;
2833 	device->con->read = samsung_early_read;
2834 	return 0;
2835 }
2836 
2837 /* S3C2410 */
2838 static struct samsung_early_console_data s3c2410_early_console_data = {
2839 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2840 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
2841 };
2842 
2843 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
2844 					      const char *opt)
2845 {
2846 	device->port.private_data = &s3c2410_early_console_data;
2847 	return samsung_early_console_setup(device, opt);
2848 }
2849 
2850 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
2851 			s3c2410_early_console_setup);
2852 
2853 /* S3C2412, S3C2440, S3C64xx */
2854 static struct samsung_early_console_data s3c2440_early_console_data = {
2855 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2856 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
2857 };
2858 
2859 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2860 					      const char *opt)
2861 {
2862 	device->port.private_data = &s3c2440_early_console_data;
2863 	return samsung_early_console_setup(device, opt);
2864 }
2865 
2866 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
2867 			s3c2440_early_console_setup);
2868 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
2869 			s3c2440_early_console_setup);
2870 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2871 			s3c2440_early_console_setup);
2872 
2873 /* S5PV210, Exynos */
2874 static struct samsung_early_console_data s5pv210_early_console_data = {
2875 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2876 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
2877 };
2878 
2879 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2880 					      const char *opt)
2881 {
2882 	device->port.private_data = &s5pv210_early_console_data;
2883 	return samsung_early_console_setup(device, opt);
2884 }
2885 
2886 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2887 			s5pv210_early_console_setup);
2888 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2889 			s5pv210_early_console_setup);
2890 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
2891 			s5pv210_early_console_setup);
2892 
2893 /* Apple S5L */
2894 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
2895 						const char *opt)
2896 {
2897 	/* Close enough to S3C2410 for earlycon... */
2898 	device->port.private_data = &s3c2410_early_console_data;
2899 
2900 #ifdef CONFIG_ARM64
2901 	/* ... but we need to override the existing fixmap entry as nGnRnE */
2902 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
2903 		     __pgprot(PROT_DEVICE_nGnRnE));
2904 #endif
2905 	return samsung_early_console_setup(device, opt);
2906 }
2907 
2908 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
2909 #endif
2910 
2911 MODULE_ALIAS("platform:samsung-uart");
2912 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2913 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2914 MODULE_LICENSE("GPL v2");
2915