xref: /linux/drivers/tty/serial/samsung_tty.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
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_S3C6400,
68 	TYPE_APPLE_S5L,
69 };
70 
71 struct s3c24xx_uart_info {
72 	const char		*name;
73 	enum s3c24xx_port_type	type;
74 	unsigned int		port_type;
75 	unsigned int		fifosize;
76 	unsigned long		rx_fifomask;
77 	unsigned long		rx_fifoshift;
78 	unsigned long		rx_fifofull;
79 	unsigned long		tx_fifomask;
80 	unsigned long		tx_fifoshift;
81 	unsigned long		tx_fifofull;
82 	unsigned int		def_clk_sel;
83 	unsigned long		num_clks;
84 	unsigned long		clksel_mask;
85 	unsigned long		clksel_shift;
86 	unsigned long		ucon_mask;
87 
88 	/* uart port features */
89 
90 	unsigned int		has_divslot:1;
91 };
92 
93 struct s3c24xx_serial_drv_data {
94 	const struct s3c24xx_uart_info	info;
95 	const struct s3c2410_uartcfg	def_cfg;
96 	const unsigned int		fifosize[UART_NR];
97 };
98 
99 struct s3c24xx_uart_dma {
100 	unsigned int			rx_chan_id;
101 	unsigned int			tx_chan_id;
102 
103 	struct dma_slave_config		rx_conf;
104 	struct dma_slave_config		tx_conf;
105 
106 	struct dma_chan			*rx_chan;
107 	struct dma_chan			*tx_chan;
108 
109 	dma_addr_t			rx_addr;
110 	dma_addr_t			tx_addr;
111 
112 	dma_cookie_t			rx_cookie;
113 	dma_cookie_t			tx_cookie;
114 
115 	char				*rx_buf;
116 
117 	dma_addr_t			tx_transfer_addr;
118 
119 	size_t				rx_size;
120 	size_t				tx_size;
121 
122 	struct dma_async_tx_descriptor	*tx_desc;
123 	struct dma_async_tx_descriptor	*rx_desc;
124 
125 	int				tx_bytes_requested;
126 	int				rx_bytes_requested;
127 };
128 
129 struct s3c24xx_uart_port {
130 	unsigned char			rx_enabled;
131 	unsigned char			tx_enabled;
132 	unsigned int			pm_level;
133 	unsigned long			baudclk_rate;
134 	unsigned int			min_dma_size;
135 
136 	unsigned int			rx_irq;
137 	unsigned int			tx_irq;
138 
139 	unsigned int			tx_in_progress;
140 	unsigned int			tx_mode;
141 	unsigned int			rx_mode;
142 
143 	const struct s3c24xx_uart_info	*info;
144 	struct clk			*clk;
145 	struct clk			*baudclk;
146 	struct uart_port		port;
147 	const struct s3c24xx_serial_drv_data	*drv_data;
148 
149 	/* reference to platform data */
150 	const struct s3c2410_uartcfg	*cfg;
151 
152 	struct s3c24xx_uart_dma		*dma;
153 };
154 
155 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
156 
157 /* conversion functions */
158 
159 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
160 
161 /* register access controls */
162 
163 #define portaddr(port, reg) ((port)->membase + (reg))
164 #define portaddrl(port, reg) \
165 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
166 
167 static u32 rd_reg(const struct uart_port *port, u32 reg)
168 {
169 	switch (port->iotype) {
170 	case UPIO_MEM:
171 		return readb_relaxed(portaddr(port, reg));
172 	case UPIO_MEM32:
173 		return readl_relaxed(portaddr(port, reg));
174 	default:
175 		return 0;
176 	}
177 	return 0;
178 }
179 
180 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
181 
182 static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
183 {
184 	switch (port->iotype) {
185 	case UPIO_MEM:
186 		writeb_relaxed(val, portaddr(port, reg));
187 		break;
188 	case UPIO_MEM32:
189 		writel_relaxed(val, portaddr(port, reg));
190 		break;
191 	}
192 }
193 
194 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
195 
196 /* Byte-order aware bit setting/clearing functions. */
197 
198 static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
199 				   unsigned int reg)
200 {
201 	unsigned long flags;
202 	u32 val;
203 
204 	local_irq_save(flags);
205 	val = rd_regl(port, reg);
206 	val |= (1 << idx);
207 	wr_regl(port, reg, val);
208 	local_irq_restore(flags);
209 }
210 
211 static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
212 				     unsigned int reg)
213 {
214 	unsigned long flags;
215 	u32 val;
216 
217 	local_irq_save(flags);
218 	val = rd_regl(port, reg);
219 	val &= ~(1 << idx);
220 	wr_regl(port, reg, val);
221 	local_irq_restore(flags);
222 }
223 
224 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
225 {
226 	return container_of(port, struct s3c24xx_uart_port, port);
227 }
228 
229 /* translate a port to the device name */
230 
231 static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
232 {
233 	return to_platform_device(port->dev)->name;
234 }
235 
236 static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
237 {
238 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
239 }
240 
241 static void s3c24xx_serial_rx_enable(struct uart_port *port)
242 {
243 	struct s3c24xx_uart_port *ourport = to_ourport(port);
244 	unsigned long flags;
245 	unsigned int ucon, ufcon;
246 	int count = 10000;
247 
248 	uart_port_lock_irqsave(port, &flags);
249 
250 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
251 		udelay(100);
252 
253 	ufcon = rd_regl(port, S3C2410_UFCON);
254 	ufcon |= S3C2410_UFCON_RESETRX;
255 	wr_regl(port, S3C2410_UFCON, ufcon);
256 
257 	ucon = rd_regl(port, S3C2410_UCON);
258 	ucon |= S3C2410_UCON_RXIRQMODE;
259 	wr_regl(port, S3C2410_UCON, ucon);
260 
261 	ourport->rx_enabled = 1;
262 	uart_port_unlock_irqrestore(port, flags);
263 }
264 
265 static void s3c24xx_serial_rx_disable(struct uart_port *port)
266 {
267 	struct s3c24xx_uart_port *ourport = to_ourport(port);
268 	unsigned long flags;
269 	unsigned int ucon;
270 
271 	uart_port_lock_irqsave(port, &flags);
272 
273 	ucon = rd_regl(port, S3C2410_UCON);
274 	ucon &= ~S3C2410_UCON_RXIRQMODE;
275 	wr_regl(port, S3C2410_UCON, ucon);
276 
277 	ourport->rx_enabled = 0;
278 	uart_port_unlock_irqrestore(port, flags);
279 }
280 
281 static void s3c24xx_serial_stop_tx(struct uart_port *port)
282 {
283 	struct s3c24xx_uart_port *ourport = to_ourport(port);
284 	struct s3c24xx_uart_dma *dma = ourport->dma;
285 	struct dma_tx_state state;
286 	int count;
287 
288 	if (!ourport->tx_enabled)
289 		return;
290 
291 	switch (ourport->info->type) {
292 	case TYPE_S3C6400:
293 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
294 		break;
295 	case TYPE_APPLE_S5L:
296 		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
297 		break;
298 	default:
299 		disable_irq_nosync(ourport->tx_irq);
300 		break;
301 	}
302 
303 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
304 		dmaengine_pause(dma->tx_chan);
305 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
306 		dmaengine_terminate_all(dma->tx_chan);
307 		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
308 					dma->tx_transfer_addr, dma->tx_size,
309 					DMA_TO_DEVICE);
310 		async_tx_ack(dma->tx_desc);
311 		count = dma->tx_bytes_requested - state.residue;
312 		uart_xmit_advance(port, count);
313 	}
314 
315 	ourport->tx_enabled = 0;
316 	ourport->tx_in_progress = 0;
317 
318 	if (port->flags & UPF_CONS_FLOW)
319 		s3c24xx_serial_rx_enable(port);
320 
321 	ourport->tx_mode = 0;
322 }
323 
324 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
325 
326 static void s3c24xx_serial_tx_dma_complete(void *args)
327 {
328 	struct s3c24xx_uart_port *ourport = args;
329 	struct uart_port *port = &ourport->port;
330 	struct circ_buf *xmit = &port->state->xmit;
331 	struct s3c24xx_uart_dma *dma = ourport->dma;
332 	struct dma_tx_state state;
333 	unsigned long flags;
334 	int count;
335 
336 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
337 	count = dma->tx_bytes_requested - state.residue;
338 	async_tx_ack(dma->tx_desc);
339 
340 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
341 				dma->tx_transfer_addr, dma->tx_size,
342 				DMA_TO_DEVICE);
343 
344 	uart_port_lock_irqsave(port, &flags);
345 
346 	uart_xmit_advance(port, count);
347 	ourport->tx_in_progress = 0;
348 
349 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
350 		uart_write_wakeup(port);
351 
352 	s3c24xx_serial_start_next_tx(ourport);
353 	uart_port_unlock_irqrestore(port, flags);
354 }
355 
356 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
357 {
358 	const struct uart_port *port = &ourport->port;
359 	u32 ucon;
360 
361 	/* Mask Tx interrupt */
362 	switch (ourport->info->type) {
363 	case TYPE_S3C6400:
364 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
365 		break;
366 	case TYPE_APPLE_S5L:
367 		WARN_ON(1); // No DMA
368 		break;
369 	default:
370 		disable_irq_nosync(ourport->tx_irq);
371 		break;
372 	}
373 
374 	/* Enable tx dma mode */
375 	ucon = rd_regl(port, S3C2410_UCON);
376 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
377 	ucon |= S3C64XX_UCON_TXBURST_1;
378 	ucon |= S3C64XX_UCON_TXMODE_DMA;
379 	wr_regl(port,  S3C2410_UCON, ucon);
380 
381 	ourport->tx_mode = S3C24XX_TX_DMA;
382 }
383 
384 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
385 {
386 	const struct uart_port *port = &ourport->port;
387 	u32 ucon, ufcon;
388 
389 	/* Set ufcon txtrig */
390 	ourport->tx_in_progress = S3C24XX_TX_PIO;
391 	ufcon = rd_regl(port, S3C2410_UFCON);
392 	wr_regl(port,  S3C2410_UFCON, ufcon);
393 
394 	/* Enable tx pio mode */
395 	ucon = rd_regl(port, S3C2410_UCON);
396 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
397 	ucon |= S3C64XX_UCON_TXMODE_CPU;
398 	wr_regl(port,  S3C2410_UCON, ucon);
399 
400 	/* Unmask Tx interrupt */
401 	switch (ourport->info->type) {
402 	case TYPE_S3C6400:
403 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
404 				  S3C64XX_UINTM);
405 		break;
406 	case TYPE_APPLE_S5L:
407 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
408 		wr_regl(port, S3C2410_UCON, ucon);
409 		break;
410 	default:
411 		enable_irq(ourport->tx_irq);
412 		break;
413 	}
414 
415 	ourport->tx_mode = S3C24XX_TX_PIO;
416 
417 	/*
418 	 * The Apple version only has edge triggered TX IRQs, so we need
419 	 * to kick off the process by sending some characters here.
420 	 */
421 	if (ourport->info->type == TYPE_APPLE_S5L)
422 		s3c24xx_serial_tx_chars(ourport);
423 }
424 
425 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
426 {
427 	if (ourport->tx_mode != S3C24XX_TX_PIO)
428 		enable_tx_pio(ourport);
429 }
430 
431 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
432 				      unsigned int count)
433 {
434 	struct uart_port *port = &ourport->port;
435 	struct circ_buf *xmit = &port->state->xmit;
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 + xmit->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 circ_buf *xmit = &port->state->xmit;
470 	unsigned long count;
471 
472 	/* Get data size up to the end of buffer */
473 	count = CIRC_CNT_TO_END(xmit->head, xmit->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 	    xmit->tail & (dma_get_cache_alignment() - 1))
483 		s3c24xx_serial_start_tx_pio(ourport);
484 	else
485 		s3c24xx_serial_start_tx_dma(ourport, count);
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 circ_buf *xmit = &port->state->xmit;
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 (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
504 			s3c24xx_serial_start_next_tx(ourport);
505 	}
506 }
507 
508 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
509 		struct tty_port *tty, int count)
510 {
511 	struct s3c24xx_uart_dma *dma = ourport->dma;
512 	int copied;
513 
514 	if (!count)
515 		return;
516 
517 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
518 				dma->rx_size, DMA_FROM_DEVICE);
519 
520 	ourport->port.icount.rx += count;
521 	if (!tty) {
522 		dev_err(ourport->port.dev, "No tty port\n");
523 		return;
524 	}
525 	copied = tty_insert_flip_string(tty,
526 			((unsigned char *)(ourport->dma->rx_buf)), count);
527 	if (copied != count) {
528 		WARN_ON(1);
529 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
530 	}
531 }
532 
533 static void s3c24xx_serial_stop_rx(struct uart_port *port)
534 {
535 	struct s3c24xx_uart_port *ourport = to_ourport(port);
536 	struct s3c24xx_uart_dma *dma = ourport->dma;
537 	struct tty_port *t = &port->state->port;
538 	struct dma_tx_state state;
539 	enum dma_status dma_status;
540 	unsigned int received;
541 
542 	if (ourport->rx_enabled) {
543 		dev_dbg(port->dev, "stopping rx\n");
544 		switch (ourport->info->type) {
545 		case TYPE_S3C6400:
546 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
547 					S3C64XX_UINTM);
548 			break;
549 		case TYPE_APPLE_S5L:
550 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
551 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
552 			break;
553 		default:
554 			disable_irq_nosync(ourport->rx_irq);
555 			break;
556 		}
557 		ourport->rx_enabled = 0;
558 	}
559 	if (dma && dma->rx_chan) {
560 		dmaengine_pause(dma->tx_chan);
561 		dma_status = dmaengine_tx_status(dma->rx_chan,
562 				dma->rx_cookie, &state);
563 		if (dma_status == DMA_IN_PROGRESS ||
564 			dma_status == DMA_PAUSED) {
565 			received = dma->rx_bytes_requested - state.residue;
566 			dmaengine_terminate_all(dma->rx_chan);
567 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
568 		}
569 	}
570 }
571 
572 static inline const struct s3c24xx_uart_info
573 	*s3c24xx_port_to_info(struct uart_port *port)
574 {
575 	return to_ourport(port)->info;
576 }
577 
578 static inline const struct s3c2410_uartcfg
579 	*s3c24xx_port_to_cfg(const struct uart_port *port)
580 {
581 	const struct s3c24xx_uart_port *ourport;
582 
583 	if (port->dev == NULL)
584 		return NULL;
585 
586 	ourport = container_of(port, struct s3c24xx_uart_port, port);
587 	return ourport->cfg;
588 }
589 
590 static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
591 				     unsigned long ufstat)
592 {
593 	const struct s3c24xx_uart_info *info = ourport->info;
594 
595 	if (ufstat & info->rx_fifofull)
596 		return ourport->port.fifosize;
597 
598 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
599 }
600 
601 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
602 static void s3c24xx_serial_rx_dma_complete(void *args)
603 {
604 	struct s3c24xx_uart_port *ourport = args;
605 	struct uart_port *port = &ourport->port;
606 
607 	struct s3c24xx_uart_dma *dma = ourport->dma;
608 	struct tty_port *t = &port->state->port;
609 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
610 
611 	struct dma_tx_state state;
612 	unsigned long flags;
613 	int received;
614 
615 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
616 	received  = dma->rx_bytes_requested - state.residue;
617 	async_tx_ack(dma->rx_desc);
618 
619 	uart_port_lock_irqsave(port, &flags);
620 
621 	if (received)
622 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
623 
624 	if (tty) {
625 		tty_flip_buffer_push(t);
626 		tty_kref_put(tty);
627 	}
628 
629 	s3c64xx_start_rx_dma(ourport);
630 
631 	uart_port_unlock_irqrestore(port, flags);
632 }
633 
634 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
635 {
636 	struct s3c24xx_uart_dma *dma = ourport->dma;
637 
638 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
639 				   dma->rx_size, DMA_FROM_DEVICE);
640 
641 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
642 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
643 				DMA_PREP_INTERRUPT);
644 	if (!dma->rx_desc) {
645 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
646 		return;
647 	}
648 
649 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
650 	dma->rx_desc->callback_param = ourport;
651 	dma->rx_bytes_requested = dma->rx_size;
652 
653 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
654 	dma_async_issue_pending(dma->rx_chan);
655 }
656 
657 /* ? - where has parity gone?? */
658 #define S3C2410_UERSTAT_PARITY (0x1000)
659 
660 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
661 {
662 	struct uart_port *port = &ourport->port;
663 	unsigned int ucon;
664 
665 	/* set Rx mode to DMA mode */
666 	ucon = rd_regl(port, S3C2410_UCON);
667 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
668 			S3C64XX_UCON_TIMEOUT_MASK |
669 			S3C64XX_UCON_EMPTYINT_EN |
670 			S3C64XX_UCON_DMASUS_EN |
671 			S3C64XX_UCON_TIMEOUT_EN |
672 			S3C64XX_UCON_RXMODE_MASK);
673 	ucon |= S3C64XX_UCON_RXBURST_1 |
674 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
675 			S3C64XX_UCON_EMPTYINT_EN |
676 			S3C64XX_UCON_TIMEOUT_EN |
677 			S3C64XX_UCON_RXMODE_DMA;
678 	wr_regl(port, S3C2410_UCON, ucon);
679 
680 	ourport->rx_mode = S3C24XX_RX_DMA;
681 }
682 
683 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
684 {
685 	struct uart_port *port = &ourport->port;
686 	unsigned int ucon;
687 
688 	/* set Rx mode to DMA mode */
689 	ucon = rd_regl(port, S3C2410_UCON);
690 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
691 	ucon |= S3C64XX_UCON_RXMODE_CPU;
692 
693 	/* Apple types use these bits for IRQ masks */
694 	if (ourport->info->type != TYPE_APPLE_S5L) {
695 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
696 				S3C64XX_UCON_EMPTYINT_EN |
697 				S3C64XX_UCON_DMASUS_EN |
698 				S3C64XX_UCON_TIMEOUT_EN);
699 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
700 				S3C64XX_UCON_TIMEOUT_EN;
701 	}
702 	wr_regl(port, S3C2410_UCON, ucon);
703 
704 	ourport->rx_mode = S3C24XX_RX_PIO;
705 }
706 
707 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
708 
709 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
710 {
711 	unsigned int utrstat, received;
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 
719 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
720 	rd_regl(port, S3C2410_UFSTAT);
721 
722 	uart_port_lock(port);
723 
724 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
725 		s3c64xx_start_rx_dma(ourport);
726 		if (ourport->rx_mode == S3C24XX_RX_PIO)
727 			enable_rx_dma(ourport);
728 		goto finish;
729 	}
730 
731 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
732 		dmaengine_pause(dma->rx_chan);
733 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
734 		dmaengine_terminate_all(dma->rx_chan);
735 		received = dma->rx_bytes_requested - state.residue;
736 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
737 
738 		enable_rx_pio(ourport);
739 	}
740 
741 	s3c24xx_serial_rx_drain_fifo(ourport);
742 
743 	if (tty) {
744 		tty_flip_buffer_push(t);
745 		tty_kref_put(tty);
746 	}
747 
748 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
749 
750 finish:
751 	uart_port_unlock(port);
752 
753 	return IRQ_HANDLED;
754 }
755 
756 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
757 {
758 	struct uart_port *port = &ourport->port;
759 	unsigned int ufcon, ufstat, uerstat;
760 	unsigned int fifocnt = 0;
761 	int max_count = port->fifosize;
762 	u8 ch, flag;
763 
764 	while (max_count-- > 0) {
765 		/*
766 		 * Receive all characters known to be in FIFO
767 		 * before reading FIFO level again
768 		 */
769 		if (fifocnt == 0) {
770 			ufstat = rd_regl(port, S3C2410_UFSTAT);
771 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
772 			if (fifocnt == 0)
773 				break;
774 		}
775 		fifocnt--;
776 
777 		uerstat = rd_regl(port, S3C2410_UERSTAT);
778 		ch = rd_reg(port, S3C2410_URXH);
779 
780 		if (port->flags & UPF_CONS_FLOW) {
781 			int txe = s3c24xx_serial_txempty_nofifo(port);
782 
783 			if (ourport->rx_enabled) {
784 				if (!txe) {
785 					ourport->rx_enabled = 0;
786 					continue;
787 				}
788 			} else {
789 				if (txe) {
790 					ufcon = rd_regl(port, S3C2410_UFCON);
791 					ufcon |= S3C2410_UFCON_RESETRX;
792 					wr_regl(port, S3C2410_UFCON, ufcon);
793 					ourport->rx_enabled = 1;
794 					return;
795 				}
796 				continue;
797 			}
798 		}
799 
800 		/* insert the character into the buffer */
801 
802 		flag = TTY_NORMAL;
803 		port->icount.rx++;
804 
805 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
806 			dev_dbg(port->dev,
807 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
808 				ch, uerstat);
809 
810 			/* check for break */
811 			if (uerstat & S3C2410_UERSTAT_BREAK) {
812 				dev_dbg(port->dev, "break!\n");
813 				port->icount.brk++;
814 				if (uart_handle_break(port))
815 					continue; /* Ignore character */
816 			}
817 
818 			if (uerstat & S3C2410_UERSTAT_FRAME)
819 				port->icount.frame++;
820 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
821 				port->icount.overrun++;
822 
823 			uerstat &= port->read_status_mask;
824 
825 			if (uerstat & S3C2410_UERSTAT_BREAK)
826 				flag = TTY_BREAK;
827 			else if (uerstat & S3C2410_UERSTAT_PARITY)
828 				flag = TTY_PARITY;
829 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
830 					    S3C2410_UERSTAT_OVERRUN))
831 				flag = TTY_FRAME;
832 		}
833 
834 		if (uart_handle_sysrq_char(port, ch))
835 			continue; /* Ignore character */
836 
837 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
838 				 ch, flag);
839 	}
840 
841 	tty_flip_buffer_push(&port->state->port);
842 }
843 
844 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
845 {
846 	struct s3c24xx_uart_port *ourport = dev_id;
847 	struct uart_port *port = &ourport->port;
848 
849 	uart_port_lock(port);
850 	s3c24xx_serial_rx_drain_fifo(ourport);
851 	uart_port_unlock(port);
852 
853 	return IRQ_HANDLED;
854 }
855 
856 static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id)
857 {
858 	struct s3c24xx_uart_port *ourport = dev_id;
859 
860 	if (ourport->dma && ourport->dma->rx_chan)
861 		return s3c24xx_serial_rx_chars_dma(dev_id);
862 	return s3c24xx_serial_rx_chars_pio(dev_id);
863 }
864 
865 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport)
866 {
867 	struct uart_port *port = &ourport->port;
868 	struct circ_buf *xmit = &port->state->xmit;
869 	int count, dma_count = 0;
870 
871 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
872 
873 	if (ourport->dma && ourport->dma->tx_chan &&
874 	    count >= ourport->min_dma_size) {
875 		int align = dma_get_cache_alignment() -
876 			(xmit->tail & (dma_get_cache_alignment() - 1));
877 		if (count - align >= ourport->min_dma_size) {
878 			dma_count = count - align;
879 			count = align;
880 		}
881 	}
882 
883 	if (port->x_char) {
884 		wr_reg(port, S3C2410_UTXH, port->x_char);
885 		port->icount.tx++;
886 		port->x_char = 0;
887 		return;
888 	}
889 
890 	/* if there isn't anything more to transmit, or the uart is now
891 	 * stopped, disable the uart and exit
892 	 */
893 
894 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
895 		s3c24xx_serial_stop_tx(port);
896 		return;
897 	}
898 
899 	/* try and drain the buffer... */
900 
901 	if (count > port->fifosize) {
902 		count = port->fifosize;
903 		dma_count = 0;
904 	}
905 
906 	while (!uart_circ_empty(xmit) && count > 0) {
907 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
908 			break;
909 
910 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
911 		uart_xmit_advance(port, 1);
912 		count--;
913 	}
914 
915 	if (!count && dma_count) {
916 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
917 		return;
918 	}
919 
920 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
921 		uart_write_wakeup(port);
922 
923 	if (uart_circ_empty(xmit))
924 		s3c24xx_serial_stop_tx(port);
925 }
926 
927 static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
928 {
929 	struct s3c24xx_uart_port *ourport = id;
930 	struct uart_port *port = &ourport->port;
931 
932 	uart_port_lock(port);
933 
934 	s3c24xx_serial_tx_chars(ourport);
935 
936 	uart_port_unlock(port);
937 	return IRQ_HANDLED;
938 }
939 
940 /* interrupt handler for s3c64xx and later SoC's.*/
941 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
942 {
943 	const struct s3c24xx_uart_port *ourport = id;
944 	const struct uart_port *port = &ourport->port;
945 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
946 	irqreturn_t ret = IRQ_HANDLED;
947 
948 	if (pend & S3C64XX_UINTM_RXD_MSK) {
949 		ret = s3c24xx_serial_rx_irq(irq, id);
950 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
951 	}
952 	if (pend & S3C64XX_UINTM_TXD_MSK) {
953 		ret = s3c24xx_serial_tx_irq(irq, id);
954 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
955 	}
956 	return ret;
957 }
958 
959 /* interrupt handler for Apple SoC's.*/
960 static irqreturn_t apple_serial_handle_irq(int irq, void *id)
961 {
962 	const struct s3c24xx_uart_port *ourport = id;
963 	const struct uart_port *port = &ourport->port;
964 	unsigned int pend = rd_regl(port, S3C2410_UTRSTAT);
965 	irqreturn_t ret = IRQ_NONE;
966 
967 	if (pend & (APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO)) {
968 		wr_regl(port, S3C2410_UTRSTAT,
969 			APPLE_S5L_UTRSTAT_RXTHRESH | APPLE_S5L_UTRSTAT_RXTO);
970 		ret = s3c24xx_serial_rx_irq(irq, id);
971 	}
972 	if (pend & APPLE_S5L_UTRSTAT_TXTHRESH) {
973 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_TXTHRESH);
974 		ret = s3c24xx_serial_tx_irq(irq, id);
975 	}
976 
977 	return ret;
978 }
979 
980 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
981 {
982 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
983 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
984 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
985 
986 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
987 		if ((ufstat & info->tx_fifomask) != 0 ||
988 		    (ufstat & info->tx_fifofull))
989 			return 0;
990 
991 		return 1;
992 	}
993 
994 	return s3c24xx_serial_txempty_nofifo(port);
995 }
996 
997 /* no modem control lines */
998 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
999 {
1000 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
1001 
1002 	if (umstat & S3C2410_UMSTAT_CTS)
1003 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1004 	else
1005 		return TIOCM_CAR | TIOCM_DSR;
1006 }
1007 
1008 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1009 {
1010 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
1011 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
1012 
1013 	if (mctrl & TIOCM_RTS)
1014 		umcon |= S3C2410_UMCOM_RTS_LOW;
1015 	else
1016 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1017 
1018 	wr_regl(port, S3C2410_UMCON, umcon);
1019 
1020 	if (mctrl & TIOCM_LOOP)
1021 		ucon |= S3C2410_UCON_LOOPBACK;
1022 	else
1023 		ucon &= ~S3C2410_UCON_LOOPBACK;
1024 
1025 	wr_regl(port, S3C2410_UCON, ucon);
1026 }
1027 
1028 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1029 {
1030 	unsigned long flags;
1031 	unsigned int ucon;
1032 
1033 	uart_port_lock_irqsave(port, &flags);
1034 
1035 	ucon = rd_regl(port, S3C2410_UCON);
1036 
1037 	if (break_state)
1038 		ucon |= S3C2410_UCON_SBREAK;
1039 	else
1040 		ucon &= ~S3C2410_UCON_SBREAK;
1041 
1042 	wr_regl(port, S3C2410_UCON, ucon);
1043 
1044 	uart_port_unlock_irqrestore(port, flags);
1045 }
1046 
1047 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1048 {
1049 	struct s3c24xx_uart_dma	*dma = p->dma;
1050 	struct dma_slave_caps dma_caps;
1051 	const char *reason = NULL;
1052 	int ret;
1053 
1054 	/* Default slave configuration parameters */
1055 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1056 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1057 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1058 	dma->rx_conf.src_maxburst	= 1;
1059 
1060 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1061 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1062 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1063 	dma->tx_conf.dst_maxburst	= 1;
1064 
1065 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1066 
1067 	if (IS_ERR(dma->rx_chan)) {
1068 		reason = "DMA RX channel request failed";
1069 		ret = PTR_ERR(dma->rx_chan);
1070 		goto err_warn;
1071 	}
1072 
1073 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1074 	if (ret < 0 ||
1075 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1076 		reason = "insufficient DMA RX engine capabilities";
1077 		ret = -EOPNOTSUPP;
1078 		goto err_release_rx;
1079 	}
1080 
1081 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1082 
1083 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1084 	if (IS_ERR(dma->tx_chan)) {
1085 		reason = "DMA TX channel request failed";
1086 		ret = PTR_ERR(dma->tx_chan);
1087 		goto err_release_rx;
1088 	}
1089 
1090 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1091 	if (ret < 0 ||
1092 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1093 		reason = "insufficient DMA TX engine capabilities";
1094 		ret = -EOPNOTSUPP;
1095 		goto err_release_tx;
1096 	}
1097 
1098 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1099 
1100 	/* RX buffer */
1101 	dma->rx_size = PAGE_SIZE;
1102 
1103 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1104 	if (!dma->rx_buf) {
1105 		ret = -ENOMEM;
1106 		goto err_release_tx;
1107 	}
1108 
1109 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1110 				      dma->rx_size, DMA_FROM_DEVICE);
1111 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1112 		reason = "DMA mapping error for RX buffer";
1113 		ret = -EIO;
1114 		goto err_free_rx;
1115 	}
1116 
1117 	/* TX buffer */
1118 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1119 				      p->port.state->xmit.buf, UART_XMIT_SIZE,
1120 				      DMA_TO_DEVICE);
1121 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1122 		reason = "DMA mapping error for TX buffer";
1123 		ret = -EIO;
1124 		goto err_unmap_rx;
1125 	}
1126 
1127 	return 0;
1128 
1129 err_unmap_rx:
1130 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1131 			 dma->rx_size, DMA_FROM_DEVICE);
1132 err_free_rx:
1133 	kfree(dma->rx_buf);
1134 err_release_tx:
1135 	dma_release_channel(dma->tx_chan);
1136 err_release_rx:
1137 	dma_release_channel(dma->rx_chan);
1138 err_warn:
1139 	if (reason)
1140 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1141 	return ret;
1142 }
1143 
1144 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1145 {
1146 	struct s3c24xx_uart_dma	*dma = p->dma;
1147 
1148 	if (dma->rx_chan) {
1149 		dmaengine_terminate_all(dma->rx_chan);
1150 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1151 				 dma->rx_size, DMA_FROM_DEVICE);
1152 		kfree(dma->rx_buf);
1153 		dma_release_channel(dma->rx_chan);
1154 		dma->rx_chan = NULL;
1155 	}
1156 
1157 	if (dma->tx_chan) {
1158 		dmaengine_terminate_all(dma->tx_chan);
1159 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1160 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1161 		dma_release_channel(dma->tx_chan);
1162 		dma->tx_chan = NULL;
1163 	}
1164 }
1165 
1166 static void s3c64xx_serial_shutdown(struct uart_port *port)
1167 {
1168 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1169 
1170 	ourport->tx_enabled = 0;
1171 	ourport->tx_mode = 0;
1172 	ourport->rx_enabled = 0;
1173 
1174 	free_irq(port->irq, ourport);
1175 
1176 	wr_regl(port, S3C64XX_UINTP, 0xf);
1177 	wr_regl(port, S3C64XX_UINTM, 0xf);
1178 
1179 	if (ourport->dma)
1180 		s3c24xx_serial_release_dma(ourport);
1181 
1182 	ourport->tx_in_progress = 0;
1183 }
1184 
1185 static void apple_s5l_serial_shutdown(struct uart_port *port)
1186 {
1187 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1188 
1189 	unsigned int ucon;
1190 
1191 	ucon = rd_regl(port, S3C2410_UCON);
1192 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1193 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1194 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1195 	wr_regl(port, S3C2410_UCON, ucon);
1196 
1197 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1198 
1199 	free_irq(port->irq, ourport);
1200 
1201 	ourport->tx_enabled = 0;
1202 	ourport->tx_mode = 0;
1203 	ourport->rx_enabled = 0;
1204 
1205 	if (ourport->dma)
1206 		s3c24xx_serial_release_dma(ourport);
1207 
1208 	ourport->tx_in_progress = 0;
1209 }
1210 
1211 static int s3c64xx_serial_startup(struct uart_port *port)
1212 {
1213 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1214 	unsigned long flags;
1215 	unsigned int ufcon;
1216 	int ret;
1217 
1218 	wr_regl(port, S3C64XX_UINTM, 0xf);
1219 	if (ourport->dma) {
1220 		ret = s3c24xx_serial_request_dma(ourport);
1221 		if (ret < 0) {
1222 			devm_kfree(port->dev, ourport->dma);
1223 			ourport->dma = NULL;
1224 		}
1225 	}
1226 
1227 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1228 			  s3c24xx_serial_portname(port), ourport);
1229 	if (ret) {
1230 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1231 		return ret;
1232 	}
1233 
1234 	/* For compatibility with s3c24xx Soc's */
1235 	ourport->rx_enabled = 1;
1236 	ourport->tx_enabled = 0;
1237 
1238 	uart_port_lock_irqsave(port, &flags);
1239 
1240 	ufcon = rd_regl(port, S3C2410_UFCON);
1241 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1242 	if (!uart_console(port))
1243 		ufcon |= S3C2410_UFCON_RESETTX;
1244 	wr_regl(port, S3C2410_UFCON, ufcon);
1245 
1246 	enable_rx_pio(ourport);
1247 
1248 	uart_port_unlock_irqrestore(port, flags);
1249 
1250 	/* Enable Rx Interrupt */
1251 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1252 
1253 	return ret;
1254 }
1255 
1256 static int apple_s5l_serial_startup(struct uart_port *port)
1257 {
1258 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1259 	unsigned long flags;
1260 	unsigned int ufcon;
1261 	int ret;
1262 
1263 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1264 
1265 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1266 			  s3c24xx_serial_portname(port), ourport);
1267 	if (ret) {
1268 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1269 		return ret;
1270 	}
1271 
1272 	/* For compatibility with s3c24xx Soc's */
1273 	ourport->rx_enabled = 1;
1274 	ourport->tx_enabled = 0;
1275 
1276 	uart_port_lock_irqsave(port, &flags);
1277 
1278 	ufcon = rd_regl(port, S3C2410_UFCON);
1279 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1280 	if (!uart_console(port))
1281 		ufcon |= S3C2410_UFCON_RESETTX;
1282 	wr_regl(port, S3C2410_UFCON, ufcon);
1283 
1284 	enable_rx_pio(ourport);
1285 
1286 	uart_port_unlock_irqrestore(port, flags);
1287 
1288 	/* Enable Rx Interrupt */
1289 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1290 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1291 
1292 	return ret;
1293 }
1294 
1295 /* power power management control */
1296 
1297 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1298 			      unsigned int old)
1299 {
1300 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1301 	int timeout = 10000;
1302 
1303 	ourport->pm_level = level;
1304 
1305 	switch (level) {
1306 	case 3:
1307 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1308 			udelay(100);
1309 
1310 		if (!IS_ERR(ourport->baudclk))
1311 			clk_disable_unprepare(ourport->baudclk);
1312 
1313 		clk_disable_unprepare(ourport->clk);
1314 		break;
1315 
1316 	case 0:
1317 		clk_prepare_enable(ourport->clk);
1318 
1319 		if (!IS_ERR(ourport->baudclk))
1320 			clk_prepare_enable(ourport->baudclk);
1321 		break;
1322 	default:
1323 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1324 	}
1325 }
1326 
1327 /* baud rate calculation
1328  *
1329  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1330  * of different sources, including the peripheral clock ("pclk") and an
1331  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1332  * with a programmable extra divisor.
1333  *
1334  * The following code goes through the clock sources, and calculates the
1335  * baud clocks (and the resultant actual baud rates) and then tries to
1336  * pick the closest one and select that.
1337  *
1338  */
1339 
1340 #define MAX_CLK_NAME_LENGTH 15
1341 
1342 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1343 {
1344 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1345 	unsigned int ucon;
1346 
1347 	if (info->num_clks == 1)
1348 		return 0;
1349 
1350 	ucon = rd_regl(port, S3C2410_UCON);
1351 	ucon &= info->clksel_mask;
1352 	return ucon >> info->clksel_shift;
1353 }
1354 
1355 static void s3c24xx_serial_setsource(struct uart_port *port,
1356 			unsigned int clk_sel)
1357 {
1358 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1359 	unsigned int ucon;
1360 
1361 	if (info->num_clks == 1)
1362 		return;
1363 
1364 	ucon = rd_regl(port, S3C2410_UCON);
1365 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1366 		return;
1367 
1368 	ucon &= ~info->clksel_mask;
1369 	ucon |= clk_sel << info->clksel_shift;
1370 	wr_regl(port, S3C2410_UCON, ucon);
1371 }
1372 
1373 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1374 			unsigned int req_baud, struct clk **best_clk,
1375 			unsigned int *clk_num)
1376 {
1377 	const struct s3c24xx_uart_info *info = ourport->info;
1378 	struct clk *clk;
1379 	unsigned long rate;
1380 	unsigned int cnt, baud, quot, best_quot = 0;
1381 	char clkname[MAX_CLK_NAME_LENGTH];
1382 	int calc_deviation, deviation = (1 << 30) - 1;
1383 
1384 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1385 		/* Keep selected clock if provided */
1386 		if (ourport->cfg->clk_sel &&
1387 			!(ourport->cfg->clk_sel & (1 << cnt)))
1388 			continue;
1389 
1390 		sprintf(clkname, "clk_uart_baud%d", cnt);
1391 		clk = clk_get(ourport->port.dev, clkname);
1392 		if (IS_ERR(clk))
1393 			continue;
1394 
1395 		rate = clk_get_rate(clk);
1396 		if (!rate) {
1397 			dev_err(ourport->port.dev,
1398 				"Failed to get clock rate for %s.\n", clkname);
1399 			clk_put(clk);
1400 			continue;
1401 		}
1402 
1403 		if (ourport->info->has_divslot) {
1404 			unsigned long div = rate / req_baud;
1405 
1406 			/* The UDIVSLOT register on the newer UARTs allows us to
1407 			 * get a divisor adjustment of 1/16th on the baud clock.
1408 			 *
1409 			 * We don't keep the UDIVSLOT value (the 16ths we
1410 			 * calculated by not multiplying the baud by 16) as it
1411 			 * is easy enough to recalculate.
1412 			 */
1413 
1414 			quot = div / 16;
1415 			baud = rate / div;
1416 		} else {
1417 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1418 			baud = rate / (quot * 16);
1419 		}
1420 		quot--;
1421 
1422 		calc_deviation = abs(req_baud - baud);
1423 
1424 		if (calc_deviation < deviation) {
1425 			/*
1426 			 * If we find a better clk, release the previous one, if
1427 			 * any.
1428 			 */
1429 			if (!IS_ERR(*best_clk))
1430 				clk_put(*best_clk);
1431 			*best_clk = clk;
1432 			best_quot = quot;
1433 			*clk_num = cnt;
1434 			deviation = calc_deviation;
1435 		} else {
1436 			clk_put(clk);
1437 		}
1438 	}
1439 
1440 	return best_quot;
1441 }
1442 
1443 /* udivslot_table[]
1444  *
1445  * This table takes the fractional value of the baud divisor and gives
1446  * the recommended setting for the UDIVSLOT register.
1447  */
1448 static const u16 udivslot_table[16] = {
1449 	[0] = 0x0000,
1450 	[1] = 0x0080,
1451 	[2] = 0x0808,
1452 	[3] = 0x0888,
1453 	[4] = 0x2222,
1454 	[5] = 0x4924,
1455 	[6] = 0x4A52,
1456 	[7] = 0x54AA,
1457 	[8] = 0x5555,
1458 	[9] = 0xD555,
1459 	[10] = 0xD5D5,
1460 	[11] = 0xDDD5,
1461 	[12] = 0xDDDD,
1462 	[13] = 0xDFDD,
1463 	[14] = 0xDFDF,
1464 	[15] = 0xFFDF,
1465 };
1466 
1467 static void s3c24xx_serial_set_termios(struct uart_port *port,
1468 				       struct ktermios *termios,
1469 				       const struct ktermios *old)
1470 {
1471 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1472 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1473 	struct clk *clk = ERR_PTR(-EINVAL);
1474 	unsigned long flags;
1475 	unsigned int baud, quot, clk_sel = 0;
1476 	unsigned int ulcon;
1477 	unsigned int umcon;
1478 	unsigned int udivslot = 0;
1479 
1480 	/*
1481 	 * We don't support modem control lines.
1482 	 */
1483 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1484 	termios->c_cflag |= CLOCAL;
1485 
1486 	/*
1487 	 * Ask the core to calculate the divisor for us.
1488 	 */
1489 
1490 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1491 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1492 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1493 		quot = port->custom_divisor;
1494 	if (IS_ERR(clk))
1495 		return;
1496 
1497 	/* check to see if we need  to change clock source */
1498 
1499 	if (ourport->baudclk != clk) {
1500 		clk_prepare_enable(clk);
1501 
1502 		s3c24xx_serial_setsource(port, clk_sel);
1503 
1504 		if (!IS_ERR(ourport->baudclk)) {
1505 			clk_disable_unprepare(ourport->baudclk);
1506 			ourport->baudclk = ERR_PTR(-EINVAL);
1507 		}
1508 
1509 		ourport->baudclk = clk;
1510 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1511 	}
1512 
1513 	if (ourport->info->has_divslot) {
1514 		unsigned int div = ourport->baudclk_rate / baud;
1515 
1516 		if (cfg->has_fracval) {
1517 			udivslot = (div & 15);
1518 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1519 		} else {
1520 			udivslot = udivslot_table[div & 15];
1521 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1522 				udivslot, div & 15);
1523 		}
1524 	}
1525 
1526 	switch (termios->c_cflag & CSIZE) {
1527 	case CS5:
1528 		dev_dbg(port->dev, "config: 5bits/char\n");
1529 		ulcon = S3C2410_LCON_CS5;
1530 		break;
1531 	case CS6:
1532 		dev_dbg(port->dev, "config: 6bits/char\n");
1533 		ulcon = S3C2410_LCON_CS6;
1534 		break;
1535 	case CS7:
1536 		dev_dbg(port->dev, "config: 7bits/char\n");
1537 		ulcon = S3C2410_LCON_CS7;
1538 		break;
1539 	case CS8:
1540 	default:
1541 		dev_dbg(port->dev, "config: 8bits/char\n");
1542 		ulcon = S3C2410_LCON_CS8;
1543 		break;
1544 	}
1545 
1546 	/* preserve original lcon IR settings */
1547 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1548 
1549 	if (termios->c_cflag & CSTOPB)
1550 		ulcon |= S3C2410_LCON_STOPB;
1551 
1552 	if (termios->c_cflag & PARENB) {
1553 		if (termios->c_cflag & PARODD)
1554 			ulcon |= S3C2410_LCON_PODD;
1555 		else
1556 			ulcon |= S3C2410_LCON_PEVEN;
1557 	} else {
1558 		ulcon |= S3C2410_LCON_PNONE;
1559 	}
1560 
1561 	uart_port_lock_irqsave(port, &flags);
1562 
1563 	dev_dbg(port->dev,
1564 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1565 		ulcon, quot, udivslot);
1566 
1567 	wr_regl(port, S3C2410_ULCON, ulcon);
1568 	wr_regl(port, S3C2410_UBRDIV, quot);
1569 
1570 	port->status &= ~UPSTAT_AUTOCTS;
1571 
1572 	umcon = rd_regl(port, S3C2410_UMCON);
1573 	if (termios->c_cflag & CRTSCTS) {
1574 		umcon |= S3C2410_UMCOM_AFC;
1575 		/* Disable RTS when RX FIFO contains 63 bytes */
1576 		umcon &= ~S3C2412_UMCON_AFC_8;
1577 		port->status = UPSTAT_AUTOCTS;
1578 	} else {
1579 		umcon &= ~S3C2410_UMCOM_AFC;
1580 	}
1581 	wr_regl(port, S3C2410_UMCON, umcon);
1582 
1583 	if (ourport->info->has_divslot)
1584 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1585 
1586 	dev_dbg(port->dev,
1587 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1588 		rd_regl(port, S3C2410_ULCON),
1589 		rd_regl(port, S3C2410_UCON),
1590 		rd_regl(port, S3C2410_UFCON));
1591 
1592 	/*
1593 	 * Update the per-port timeout.
1594 	 */
1595 	uart_update_timeout(port, termios->c_cflag, baud);
1596 
1597 	/*
1598 	 * Which character status flags are we interested in?
1599 	 */
1600 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1601 	if (termios->c_iflag & INPCK)
1602 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1603 			S3C2410_UERSTAT_PARITY;
1604 	/*
1605 	 * Which character status flags should we ignore?
1606 	 */
1607 	port->ignore_status_mask = 0;
1608 	if (termios->c_iflag & IGNPAR)
1609 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1610 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1611 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1612 
1613 	/*
1614 	 * Ignore all characters if CREAD is not set.
1615 	 */
1616 	if ((termios->c_cflag & CREAD) == 0)
1617 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1618 
1619 	uart_port_unlock_irqrestore(port, flags);
1620 }
1621 
1622 static const char *s3c24xx_serial_type(struct uart_port *port)
1623 {
1624 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
1625 
1626 	switch (ourport->info->type) {
1627 	case TYPE_S3C6400:
1628 		return "S3C6400/10";
1629 	case TYPE_APPLE_S5L:
1630 		return "APPLE S5L";
1631 	default:
1632 		return NULL;
1633 	}
1634 }
1635 
1636 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1637 {
1638 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1639 
1640 	if (flags & UART_CONFIG_TYPE)
1641 		port->type = info->port_type;
1642 }
1643 
1644 /*
1645  * verify the new serial_struct (for TIOCSSERIAL).
1646  */
1647 static int
1648 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1649 {
1650 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1651 
1652 	if (ser->type != PORT_UNKNOWN && ser->type != info->port_type)
1653 		return -EINVAL;
1654 
1655 	return 0;
1656 }
1657 
1658 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1659 
1660 static struct console s3c24xx_serial_console;
1661 
1662 static void __init s3c24xx_serial_register_console(void)
1663 {
1664 	register_console(&s3c24xx_serial_console);
1665 }
1666 
1667 static void s3c24xx_serial_unregister_console(void)
1668 {
1669 	if (console_is_registered(&s3c24xx_serial_console))
1670 		unregister_console(&s3c24xx_serial_console);
1671 }
1672 
1673 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1674 #else
1675 static inline void s3c24xx_serial_register_console(void) { }
1676 static inline void s3c24xx_serial_unregister_console(void) { }
1677 #define S3C24XX_SERIAL_CONSOLE NULL
1678 #endif
1679 
1680 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1681 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1682 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1683 			 unsigned char c);
1684 #endif
1685 
1686 static const struct uart_ops s3c64xx_serial_ops = {
1687 	.pm		= s3c24xx_serial_pm,
1688 	.tx_empty	= s3c24xx_serial_tx_empty,
1689 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1690 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1691 	.stop_tx	= s3c24xx_serial_stop_tx,
1692 	.start_tx	= s3c24xx_serial_start_tx,
1693 	.stop_rx	= s3c24xx_serial_stop_rx,
1694 	.break_ctl	= s3c24xx_serial_break_ctl,
1695 	.startup	= s3c64xx_serial_startup,
1696 	.shutdown	= s3c64xx_serial_shutdown,
1697 	.set_termios	= s3c24xx_serial_set_termios,
1698 	.type		= s3c24xx_serial_type,
1699 	.config_port	= s3c24xx_serial_config_port,
1700 	.verify_port	= s3c24xx_serial_verify_port,
1701 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1702 	.poll_get_char = s3c24xx_serial_get_poll_char,
1703 	.poll_put_char = s3c24xx_serial_put_poll_char,
1704 #endif
1705 };
1706 
1707 static const struct uart_ops apple_s5l_serial_ops = {
1708 	.pm		= s3c24xx_serial_pm,
1709 	.tx_empty	= s3c24xx_serial_tx_empty,
1710 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1711 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1712 	.stop_tx	= s3c24xx_serial_stop_tx,
1713 	.start_tx	= s3c24xx_serial_start_tx,
1714 	.stop_rx	= s3c24xx_serial_stop_rx,
1715 	.break_ctl	= s3c24xx_serial_break_ctl,
1716 	.startup	= apple_s5l_serial_startup,
1717 	.shutdown	= apple_s5l_serial_shutdown,
1718 	.set_termios	= s3c24xx_serial_set_termios,
1719 	.type		= s3c24xx_serial_type,
1720 	.config_port	= s3c24xx_serial_config_port,
1721 	.verify_port	= s3c24xx_serial_verify_port,
1722 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1723 	.poll_get_char = s3c24xx_serial_get_poll_char,
1724 	.poll_put_char = s3c24xx_serial_put_poll_char,
1725 #endif
1726 };
1727 
1728 static struct uart_driver s3c24xx_uart_drv = {
1729 	.owner		= THIS_MODULE,
1730 	.driver_name	= "s3c2410_serial",
1731 	.nr		= UART_NR,
1732 	.cons		= S3C24XX_SERIAL_CONSOLE,
1733 	.dev_name	= S3C24XX_SERIAL_NAME,
1734 	.major		= S3C24XX_SERIAL_MAJOR,
1735 	.minor		= S3C24XX_SERIAL_MINOR,
1736 };
1737 
1738 static struct s3c24xx_uart_port s3c24xx_serial_ports[UART_NR];
1739 
1740 static void s3c24xx_serial_init_port_default(int index) {
1741 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1742 
1743 	spin_lock_init(&port->lock);
1744 
1745 	port->iotype = UPIO_MEM;
1746 	port->uartclk = 0;
1747 	port->fifosize = 16;
1748 	port->flags = UPF_BOOT_AUTOCONF;
1749 	port->line = index;
1750 }
1751 
1752 /* s3c24xx_serial_resetport
1753  *
1754  * reset the fifos and other the settings.
1755  */
1756 
1757 static void s3c24xx_serial_resetport(struct uart_port *port,
1758 				     const struct s3c2410_uartcfg *cfg)
1759 {
1760 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1761 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1762 
1763 	ucon &= (info->clksel_mask | info->ucon_mask);
1764 	wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
1765 
1766 	/* reset both fifos */
1767 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1768 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1769 
1770 	/* some delay is required after fifo reset */
1771 	udelay(1);
1772 }
1773 
1774 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1775 {
1776 	struct device *dev = ourport->port.dev;
1777 	const struct s3c24xx_uart_info *info = ourport->info;
1778 	char clk_name[MAX_CLK_NAME_LENGTH];
1779 	unsigned int clk_sel;
1780 	struct clk *clk;
1781 	int clk_num;
1782 	int ret;
1783 
1784 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1785 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1786 		if (!(clk_sel & (1 << clk_num)))
1787 			continue;
1788 
1789 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1790 		clk = clk_get(dev, clk_name);
1791 		if (IS_ERR(clk))
1792 			continue;
1793 
1794 		ret = clk_prepare_enable(clk);
1795 		if (ret) {
1796 			clk_put(clk);
1797 			continue;
1798 		}
1799 
1800 		ourport->baudclk = clk;
1801 		ourport->baudclk_rate = clk_get_rate(clk);
1802 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1803 
1804 		return 0;
1805 	}
1806 
1807 	return -EINVAL;
1808 }
1809 
1810 /* s3c24xx_serial_init_port
1811  *
1812  * initialise a single serial port from the platform device given
1813  */
1814 
1815 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1816 				    struct platform_device *platdev)
1817 {
1818 	struct uart_port *port = &ourport->port;
1819 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1820 	struct resource *res;
1821 	int ret;
1822 
1823 	if (platdev == NULL)
1824 		return -ENODEV;
1825 
1826 	if (port->mapbase != 0)
1827 		return -EINVAL;
1828 
1829 	/* setup info for port */
1830 	port->dev	= &platdev->dev;
1831 
1832 	port->uartclk = 1;
1833 
1834 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1835 		dev_dbg(port->dev, "enabling flow control\n");
1836 		port->flags |= UPF_CONS_FLOW;
1837 	}
1838 
1839 	/* sort our the physical and virtual addresses for each UART */
1840 
1841 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1842 	if (res == NULL) {
1843 		dev_err(port->dev, "failed to find memory resource for uart\n");
1844 		return -EINVAL;
1845 	}
1846 
1847 	dev_dbg(port->dev, "resource %pR)\n", res);
1848 
1849 	port->membase = devm_ioremap_resource(port->dev, res);
1850 	if (IS_ERR(port->membase)) {
1851 		dev_err(port->dev, "failed to remap controller address\n");
1852 		return -EBUSY;
1853 	}
1854 
1855 	port->mapbase = res->start;
1856 	ret = platform_get_irq(platdev, 0);
1857 	if (ret < 0) {
1858 		port->irq = 0;
1859 	} else {
1860 		port->irq = ret;
1861 		ourport->rx_irq = ret;
1862 		ourport->tx_irq = ret + 1;
1863 	}
1864 
1865 	/*
1866 	 * DMA is currently supported only on DT platforms, if DMA properties
1867 	 * are specified.
1868 	 */
1869 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1870 						     "dmas", NULL)) {
1871 		ourport->dma = devm_kzalloc(port->dev,
1872 					    sizeof(*ourport->dma),
1873 					    GFP_KERNEL);
1874 		if (!ourport->dma) {
1875 			ret = -ENOMEM;
1876 			goto err;
1877 		}
1878 	}
1879 
1880 	ourport->clk	= clk_get(&platdev->dev, "uart");
1881 	if (IS_ERR(ourport->clk)) {
1882 		pr_err("%s: Controller clock not found\n",
1883 				dev_name(&platdev->dev));
1884 		ret = PTR_ERR(ourport->clk);
1885 		goto err;
1886 	}
1887 
1888 	ret = clk_prepare_enable(ourport->clk);
1889 	if (ret) {
1890 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1891 		clk_put(ourport->clk);
1892 		goto err;
1893 	}
1894 
1895 	ret = s3c24xx_serial_enable_baudclk(ourport);
1896 	if (ret)
1897 		pr_warn("uart: failed to enable baudclk\n");
1898 
1899 	/* Keep all interrupts masked and cleared */
1900 	switch (ourport->info->type) {
1901 	case TYPE_S3C6400:
1902 		wr_regl(port, S3C64XX_UINTM, 0xf);
1903 		wr_regl(port, S3C64XX_UINTP, 0xf);
1904 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1905 		break;
1906 	case TYPE_APPLE_S5L: {
1907 		unsigned int ucon;
1908 
1909 		ucon = rd_regl(port, S3C2410_UCON);
1910 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1911 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1912 			APPLE_S5L_UCON_RXTO_ENA_MSK);
1913 		wr_regl(port, S3C2410_UCON, ucon);
1914 
1915 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1916 		break;
1917 	}
1918 	default:
1919 		break;
1920 	}
1921 
1922 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1923 		&port->mapbase, port->membase, port->irq,
1924 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
1925 
1926 	/* reset the fifos (and setup the uart) */
1927 	s3c24xx_serial_resetport(port, cfg);
1928 
1929 	return 0;
1930 
1931 err:
1932 	port->mapbase = 0;
1933 	return ret;
1934 }
1935 
1936 /* Device driver serial port probe */
1937 
1938 static int probe_index;
1939 
1940 static inline const struct s3c24xx_serial_drv_data *
1941 s3c24xx_get_driver_data(struct platform_device *pdev)
1942 {
1943 	if (dev_of_node(&pdev->dev))
1944 		return of_device_get_match_data(&pdev->dev);
1945 
1946 	return (struct s3c24xx_serial_drv_data *)
1947 			platform_get_device_id(pdev)->driver_data;
1948 }
1949 
1950 static int s3c24xx_serial_probe(struct platform_device *pdev)
1951 {
1952 	struct device_node *np = pdev->dev.of_node;
1953 	struct s3c24xx_uart_port *ourport;
1954 	int index = probe_index;
1955 	int ret, prop = 0;
1956 
1957 	if (np) {
1958 		ret = of_alias_get_id(np, "serial");
1959 		if (ret >= 0)
1960 			index = ret;
1961 	}
1962 
1963 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
1964 		dev_err(&pdev->dev, "serial%d out of range\n", index);
1965 		return -EINVAL;
1966 	}
1967 	ourport = &s3c24xx_serial_ports[index];
1968 
1969 	s3c24xx_serial_init_port_default(index);
1970 
1971 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
1972 	if (!ourport->drv_data) {
1973 		dev_err(&pdev->dev, "could not find driver data\n");
1974 		return -ENODEV;
1975 	}
1976 
1977 	ourport->baudclk = ERR_PTR(-EINVAL);
1978 	ourport->info = &ourport->drv_data->info;
1979 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1980 			dev_get_platdata(&pdev->dev) :
1981 			&ourport->drv_data->def_cfg;
1982 
1983 	switch (ourport->info->type) {
1984 	case TYPE_S3C6400:
1985 		ourport->port.ops = &s3c64xx_serial_ops;
1986 		break;
1987 	case TYPE_APPLE_S5L:
1988 		ourport->port.ops = &apple_s5l_serial_ops;
1989 		break;
1990 	}
1991 
1992 	if (np) {
1993 		of_property_read_u32(np,
1994 			"samsung,uart-fifosize", &ourport->port.fifosize);
1995 
1996 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
1997 			switch (prop) {
1998 			case 1:
1999 				ourport->port.iotype = UPIO_MEM;
2000 				break;
2001 			case 4:
2002 				ourport->port.iotype = UPIO_MEM32;
2003 				break;
2004 			default:
2005 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2006 						prop);
2007 				return -EINVAL;
2008 			}
2009 		}
2010 	}
2011 
2012 	if (ourport->drv_data->fifosize[index])
2013 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2014 	else if (ourport->info->fifosize)
2015 		ourport->port.fifosize = ourport->info->fifosize;
2016 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2017 
2018 	/*
2019 	 * DMA transfers must be aligned at least to cache line size,
2020 	 * so find minimal transfer size suitable for DMA mode
2021 	 */
2022 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2023 				    dma_get_cache_alignment());
2024 
2025 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2026 
2027 	ret = s3c24xx_serial_init_port(ourport, pdev);
2028 	if (ret < 0)
2029 		return ret;
2030 
2031 	if (!s3c24xx_uart_drv.state) {
2032 		ret = uart_register_driver(&s3c24xx_uart_drv);
2033 		if (ret < 0) {
2034 			pr_err("Failed to register Samsung UART driver\n");
2035 			return ret;
2036 		}
2037 	}
2038 
2039 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2040 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2041 	platform_set_drvdata(pdev, &ourport->port);
2042 
2043 	/*
2044 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2045 	 * so that a potential re-enablement through the pm-callback overlaps
2046 	 * and keeps the clock enabled in this case.
2047 	 */
2048 	clk_disable_unprepare(ourport->clk);
2049 	if (!IS_ERR(ourport->baudclk))
2050 		clk_disable_unprepare(ourport->baudclk);
2051 
2052 	probe_index++;
2053 
2054 	return 0;
2055 }
2056 
2057 static void s3c24xx_serial_remove(struct platform_device *dev)
2058 {
2059 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2060 
2061 	if (port) {
2062 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2063 	}
2064 
2065 	uart_unregister_driver(&s3c24xx_uart_drv);
2066 }
2067 
2068 /* UART power management code */
2069 #ifdef CONFIG_PM_SLEEP
2070 static int s3c24xx_serial_suspend(struct device *dev)
2071 {
2072 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2073 
2074 	if (port)
2075 		uart_suspend_port(&s3c24xx_uart_drv, port);
2076 
2077 	return 0;
2078 }
2079 
2080 static int s3c24xx_serial_resume(struct device *dev)
2081 {
2082 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2083 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2084 
2085 	if (port) {
2086 		clk_prepare_enable(ourport->clk);
2087 		if (!IS_ERR(ourport->baudclk))
2088 			clk_prepare_enable(ourport->baudclk);
2089 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2090 		if (!IS_ERR(ourport->baudclk))
2091 			clk_disable_unprepare(ourport->baudclk);
2092 		clk_disable_unprepare(ourport->clk);
2093 
2094 		uart_resume_port(&s3c24xx_uart_drv, port);
2095 	}
2096 
2097 	return 0;
2098 }
2099 
2100 static int s3c24xx_serial_resume_noirq(struct device *dev)
2101 {
2102 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2103 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2104 
2105 	if (port) {
2106 		/* restore IRQ mask */
2107 		switch (ourport->info->type) {
2108 		case TYPE_S3C6400: {
2109 			unsigned int uintm = 0xf;
2110 
2111 			if (ourport->tx_enabled)
2112 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2113 			if (ourport->rx_enabled)
2114 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2115 			clk_prepare_enable(ourport->clk);
2116 			if (!IS_ERR(ourport->baudclk))
2117 				clk_prepare_enable(ourport->baudclk);
2118 			wr_regl(port, S3C64XX_UINTM, uintm);
2119 			if (!IS_ERR(ourport->baudclk))
2120 				clk_disable_unprepare(ourport->baudclk);
2121 			clk_disable_unprepare(ourport->clk);
2122 			break;
2123 		}
2124 		case TYPE_APPLE_S5L: {
2125 			unsigned int ucon;
2126 			int ret;
2127 
2128 			ret = clk_prepare_enable(ourport->clk);
2129 			if (ret) {
2130 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2131 				return ret;
2132 			}
2133 			if (!IS_ERR(ourport->baudclk)) {
2134 				ret = clk_prepare_enable(ourport->baudclk);
2135 				if (ret) {
2136 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2137 					clk_disable_unprepare(ourport->clk);
2138 					return ret;
2139 				}
2140 			}
2141 
2142 			ucon = rd_regl(port, S3C2410_UCON);
2143 
2144 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2145 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2146 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2147 
2148 			if (ourport->tx_enabled)
2149 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2150 			if (ourport->rx_enabled)
2151 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2152 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2153 
2154 			wr_regl(port, S3C2410_UCON, ucon);
2155 
2156 			if (!IS_ERR(ourport->baudclk))
2157 				clk_disable_unprepare(ourport->baudclk);
2158 			clk_disable_unprepare(ourport->clk);
2159 			break;
2160 		}
2161 		default:
2162 			break;
2163 		}
2164 	}
2165 
2166 	return 0;
2167 }
2168 
2169 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2170 	SET_SYSTEM_SLEEP_PM_OPS(s3c24xx_serial_suspend, s3c24xx_serial_resume)
2171 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, s3c24xx_serial_resume_noirq)
2172 };
2173 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2174 
2175 #else /* !CONFIG_PM_SLEEP */
2176 
2177 #define SERIAL_SAMSUNG_PM_OPS	NULL
2178 #endif /* CONFIG_PM_SLEEP */
2179 
2180 /* Console code */
2181 
2182 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2183 
2184 static struct uart_port *cons_uart;
2185 
2186 static int
2187 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2188 {
2189 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2190 	unsigned long ufstat, utrstat;
2191 
2192 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2193 		/* fifo mode - check amount of data in fifo registers... */
2194 
2195 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2196 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2197 	}
2198 
2199 	/* in non-fifo mode, we go and use the tx buffer empty */
2200 
2201 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2202 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2203 }
2204 
2205 static bool
2206 s3c24xx_port_configured(unsigned int ucon)
2207 {
2208 	/* consider the serial port configured if the tx/rx mode set */
2209 	return (ucon & 0xf) != 0;
2210 }
2211 
2212 #ifdef CONFIG_CONSOLE_POLL
2213 /*
2214  * Console polling routines for writing and reading from the uart while
2215  * in an interrupt or debug context.
2216  */
2217 
2218 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2219 {
2220 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2221 	unsigned int ufstat;
2222 
2223 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2224 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2225 		return NO_POLL_CHAR;
2226 
2227 	return rd_reg(port, S3C2410_URXH);
2228 }
2229 
2230 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2231 		unsigned char c)
2232 {
2233 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2234 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2235 
2236 	/* not possible to xmit on unconfigured port */
2237 	if (!s3c24xx_port_configured(ucon))
2238 		return;
2239 
2240 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2241 		cpu_relax();
2242 	wr_reg(port, S3C2410_UTXH, c);
2243 }
2244 
2245 #endif /* CONFIG_CONSOLE_POLL */
2246 
2247 static void
2248 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2249 {
2250 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2251 
2252 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2253 		cpu_relax();
2254 	wr_reg(port, S3C2410_UTXH, ch);
2255 }
2256 
2257 static void
2258 s3c24xx_serial_console_write(struct console *co, const char *s,
2259 			     unsigned int count)
2260 {
2261 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2262 	unsigned long flags;
2263 	bool locked = true;
2264 
2265 	/* not possible to xmit on unconfigured port */
2266 	if (!s3c24xx_port_configured(ucon))
2267 		return;
2268 
2269 	if (cons_uart->sysrq)
2270 		locked = false;
2271 	else if (oops_in_progress)
2272 		locked = uart_port_trylock_irqsave(cons_uart, &flags);
2273 	else
2274 		uart_port_lock_irqsave(cons_uart, &flags);
2275 
2276 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2277 
2278 	if (locked)
2279 		uart_port_unlock_irqrestore(cons_uart, flags);
2280 }
2281 
2282 /* Shouldn't be __init, as it can be instantiated from other module */
2283 static void
2284 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2285 			   int *parity, int *bits)
2286 {
2287 	struct clk *clk;
2288 	unsigned int ulcon;
2289 	unsigned int ucon;
2290 	unsigned int ubrdiv;
2291 	unsigned long rate;
2292 	unsigned int clk_sel;
2293 	char clk_name[MAX_CLK_NAME_LENGTH];
2294 
2295 	ulcon  = rd_regl(port, S3C2410_ULCON);
2296 	ucon   = rd_regl(port, S3C2410_UCON);
2297 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2298 
2299 	if (s3c24xx_port_configured(ucon)) {
2300 		switch (ulcon & S3C2410_LCON_CSMASK) {
2301 		case S3C2410_LCON_CS5:
2302 			*bits = 5;
2303 			break;
2304 		case S3C2410_LCON_CS6:
2305 			*bits = 6;
2306 			break;
2307 		case S3C2410_LCON_CS7:
2308 			*bits = 7;
2309 			break;
2310 		case S3C2410_LCON_CS8:
2311 		default:
2312 			*bits = 8;
2313 			break;
2314 		}
2315 
2316 		switch (ulcon & S3C2410_LCON_PMASK) {
2317 		case S3C2410_LCON_PEVEN:
2318 			*parity = 'e';
2319 			break;
2320 
2321 		case S3C2410_LCON_PODD:
2322 			*parity = 'o';
2323 			break;
2324 
2325 		case S3C2410_LCON_PNONE:
2326 		default:
2327 			*parity = 'n';
2328 		}
2329 
2330 		/* now calculate the baud rate */
2331 
2332 		clk_sel = s3c24xx_serial_getsource(port);
2333 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2334 
2335 		clk = clk_get(port->dev, clk_name);
2336 		if (!IS_ERR(clk))
2337 			rate = clk_get_rate(clk);
2338 		else
2339 			rate = 1;
2340 
2341 		*baud = rate / (16 * (ubrdiv + 1));
2342 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2343 	}
2344 }
2345 
2346 /* Shouldn't be __init, as it can be instantiated from other module */
2347 static int
2348 s3c24xx_serial_console_setup(struct console *co, char *options)
2349 {
2350 	struct uart_port *port;
2351 	int baud = 9600;
2352 	int bits = 8;
2353 	int parity = 'n';
2354 	int flow = 'n';
2355 
2356 	/* is this a valid port */
2357 
2358 	if (co->index == -1 || co->index >= UART_NR)
2359 		co->index = 0;
2360 
2361 	port = &s3c24xx_serial_ports[co->index].port;
2362 
2363 	/* is the port configured? */
2364 
2365 	if (port->mapbase == 0x0)
2366 		return -ENODEV;
2367 
2368 	cons_uart = port;
2369 
2370 	/*
2371 	 * Check whether an invalid uart number has been specified, and
2372 	 * if so, search for the first available port that does have
2373 	 * console support.
2374 	 */
2375 	if (options)
2376 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2377 	else
2378 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2379 
2380 	dev_dbg(port->dev, "baud %d\n", baud);
2381 
2382 	return uart_set_options(port, co, baud, parity, bits, flow);
2383 }
2384 
2385 static struct console s3c24xx_serial_console = {
2386 	.name		= S3C24XX_SERIAL_NAME,
2387 	.device		= uart_console_device,
2388 	.flags		= CON_PRINTBUFFER,
2389 	.index		= -1,
2390 	.write		= s3c24xx_serial_console_write,
2391 	.setup		= s3c24xx_serial_console_setup,
2392 	.data		= &s3c24xx_uart_drv,
2393 };
2394 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2395 
2396 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2397 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2398 	.info = {
2399 		.name		= "Samsung S3C6400 UART",
2400 		.type		= TYPE_S3C6400,
2401 		.port_type	= PORT_S3C6400,
2402 		.fifosize	= 64,
2403 		.has_divslot	= 1,
2404 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2405 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2406 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2407 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2408 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2409 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2410 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2411 		.num_clks	= 4,
2412 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2413 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2414 	},
2415 	.def_cfg = {
2416 		.ucon		= S3C2410_UCON_DEFAULT,
2417 		.ufcon		= S3C2410_UFCON_DEFAULT,
2418 	},
2419 };
2420 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2421 #else
2422 #define S3C6400_SERIAL_DRV_DATA NULL
2423 #endif
2424 
2425 #ifdef CONFIG_CPU_S5PV210
2426 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2427 	.info = {
2428 		.name		= "Samsung S5PV210 UART",
2429 		.type		= TYPE_S3C6400,
2430 		.port_type	= PORT_S3C6400,
2431 		.has_divslot	= 1,
2432 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2433 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2434 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2435 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2436 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2437 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2438 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2439 		.num_clks	= 2,
2440 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2441 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2442 	},
2443 	.def_cfg = {
2444 		.ucon		= S5PV210_UCON_DEFAULT,
2445 		.ufcon		= S5PV210_UFCON_DEFAULT,
2446 	},
2447 	.fifosize = { 256, 64, 16, 16 },
2448 };
2449 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2450 #else
2451 #define S5PV210_SERIAL_DRV_DATA	NULL
2452 #endif
2453 
2454 #if defined(CONFIG_ARCH_EXYNOS)
2455 #define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
2456 	.info = {						\
2457 		.name		= "Samsung Exynos UART",	\
2458 		.type		= TYPE_S3C6400,			\
2459 		.port_type	= PORT_S3C6400,			\
2460 		.has_divslot	= 1,				\
2461 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2462 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2463 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2464 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2465 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2466 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2467 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2468 		.num_clks	= 1,				\
2469 		.clksel_mask	= 0,				\
2470 		.clksel_shift	= 0,				\
2471 	},							\
2472 	.def_cfg = {						\
2473 		.ucon		= S5PV210_UCON_DEFAULT,		\
2474 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2475 		.has_fracval	= 1,				\
2476 	}							\
2477 
2478 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2479 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2480 	.fifosize = { 256, 64, 16, 16 },
2481 };
2482 
2483 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2484 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2485 	.fifosize = { 64, 256, 16, 256 },
2486 };
2487 
2488 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2489 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2490 	.fifosize = { 256, 64, 64, 64 },
2491 };
2492 
2493 /*
2494  * Common drv_data struct for platforms that specify samsung,uart-fifosize in
2495  * device tree.
2496  */
2497 static const struct s3c24xx_serial_drv_data exynos_fifoszdt_serial_drv_data = {
2498 	EXYNOS_COMMON_SERIAL_DRV_DATA(),
2499 	.fifosize = { 0 },
2500 };
2501 
2502 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2503 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2504 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2505 #define EXYNOS_FIFOSZDT_DRV_DATA (&exynos_fifoszdt_serial_drv_data)
2506 
2507 #else
2508 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2509 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2510 #define EXYNOS850_SERIAL_DRV_DATA NULL
2511 #define EXYNOS_FIFOSZDT_DRV_DATA NULL
2512 #endif
2513 
2514 #ifdef CONFIG_ARCH_APPLE
2515 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2516 	.info = {
2517 		.name		= "Apple S5L UART",
2518 		.type		= TYPE_APPLE_S5L,
2519 		.port_type	= PORT_8250,
2520 		.fifosize	= 16,
2521 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2522 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2523 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2524 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2525 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2526 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2527 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2528 		.num_clks	= 1,
2529 		.clksel_mask	= 0,
2530 		.clksel_shift	= 0,
2531 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2532 	},
2533 	.def_cfg = {
2534 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2535 		.ufcon		= S3C2410_UFCON_DEFAULT,
2536 	},
2537 };
2538 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2539 #else
2540 #define S5L_SERIAL_DRV_DATA NULL
2541 #endif
2542 
2543 #if defined(CONFIG_ARCH_ARTPEC)
2544 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2545 	.info = {
2546 		.name		= "Axis ARTPEC-8 UART",
2547 		.type		= TYPE_S3C6400,
2548 		.port_type	= PORT_S3C6400,
2549 		.fifosize	= 64,
2550 		.has_divslot	= 1,
2551 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2552 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2553 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2554 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2555 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2556 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2557 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2558 		.num_clks	= 1,
2559 		.clksel_mask	= 0,
2560 		.clksel_shift	= 0,
2561 	},
2562 	.def_cfg = {
2563 		.ucon		= S5PV210_UCON_DEFAULT,
2564 		.ufcon		= S5PV210_UFCON_DEFAULT,
2565 		.has_fracval	= 1,
2566 	}
2567 };
2568 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2569 #else
2570 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2571 #endif
2572 
2573 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2574 	{
2575 		.name		= "s3c6400-uart",
2576 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2577 	}, {
2578 		.name		= "s5pv210-uart",
2579 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2580 	}, {
2581 		.name		= "exynos4210-uart",
2582 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2583 	}, {
2584 		.name		= "exynos5433-uart",
2585 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2586 	}, {
2587 		.name		= "s5l-uart",
2588 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2589 	}, {
2590 		.name		= "exynos850-uart",
2591 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2592 	}, {
2593 		.name		= "artpec8-uart",
2594 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2595 	}, {
2596 		.name		= "gs101-uart",
2597 		.driver_data	= (kernel_ulong_t)EXYNOS_FIFOSZDT_DRV_DATA,
2598 	},
2599 	{ },
2600 };
2601 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2602 
2603 #ifdef CONFIG_OF
2604 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2605 	{ .compatible = "samsung,s3c6400-uart",
2606 		.data = S3C6400_SERIAL_DRV_DATA },
2607 	{ .compatible = "samsung,s5pv210-uart",
2608 		.data = S5PV210_SERIAL_DRV_DATA },
2609 	{ .compatible = "samsung,exynos4210-uart",
2610 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2611 	{ .compatible = "samsung,exynos5433-uart",
2612 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2613 	{ .compatible = "apple,s5l-uart",
2614 		.data = S5L_SERIAL_DRV_DATA },
2615 	{ .compatible = "samsung,exynos850-uart",
2616 		.data = EXYNOS850_SERIAL_DRV_DATA },
2617 	{ .compatible = "axis,artpec8-uart",
2618 		.data = ARTPEC8_SERIAL_DRV_DATA },
2619 	{ .compatible = "google,gs101-uart",
2620 		.data = EXYNOS_FIFOSZDT_DRV_DATA },
2621 	{},
2622 };
2623 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2624 #endif
2625 
2626 static struct platform_driver samsung_serial_driver = {
2627 	.probe		= s3c24xx_serial_probe,
2628 	.remove_new	= s3c24xx_serial_remove,
2629 	.id_table	= s3c24xx_serial_driver_ids,
2630 	.driver		= {
2631 		.name	= "samsung-uart",
2632 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2633 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2634 	},
2635 };
2636 
2637 static int __init samsung_serial_init(void)
2638 {
2639 	int ret;
2640 
2641 	s3c24xx_serial_register_console();
2642 
2643 	ret = platform_driver_register(&samsung_serial_driver);
2644 	if (ret) {
2645 		s3c24xx_serial_unregister_console();
2646 		return ret;
2647 	}
2648 
2649 	return 0;
2650 }
2651 
2652 static void __exit samsung_serial_exit(void)
2653 {
2654 	platform_driver_unregister(&samsung_serial_driver);
2655 	s3c24xx_serial_unregister_console();
2656 }
2657 
2658 module_init(samsung_serial_init);
2659 module_exit(samsung_serial_exit);
2660 
2661 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2662 /*
2663  * Early console.
2664  */
2665 
2666 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2667 {
2668 	switch (port->iotype) {
2669 	case UPIO_MEM:
2670 		writeb(val, portaddr(port, reg));
2671 		break;
2672 	case UPIO_MEM32:
2673 		writel(val, portaddr(port, reg));
2674 		break;
2675 	}
2676 }
2677 
2678 struct samsung_early_console_data {
2679 	u32 txfull_mask;
2680 	u32 rxfifo_mask;
2681 };
2682 
2683 static void samsung_early_busyuart(const struct uart_port *port)
2684 {
2685 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2686 		;
2687 }
2688 
2689 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2690 {
2691 	const struct samsung_early_console_data *data = port->private_data;
2692 
2693 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2694 		;
2695 }
2696 
2697 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2698 {
2699 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2700 		samsung_early_busyuart_fifo(port);
2701 	else
2702 		samsung_early_busyuart(port);
2703 
2704 	wr_reg_barrier(port, S3C2410_UTXH, c);
2705 }
2706 
2707 static void samsung_early_write(struct console *con, const char *s,
2708 				unsigned int n)
2709 {
2710 	struct earlycon_device *dev = con->data;
2711 
2712 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2713 }
2714 
2715 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2716 {
2717 	struct earlycon_device *dev = con->data;
2718 	const struct samsung_early_console_data *data = dev->port.private_data;
2719 	int ch, ufstat, num_read = 0;
2720 
2721 	while (num_read < n) {
2722 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
2723 		if (!(ufstat & data->rxfifo_mask))
2724 			break;
2725 		ch = rd_reg(&dev->port, S3C2410_URXH);
2726 		if (ch == NO_POLL_CHAR)
2727 			break;
2728 
2729 		s[num_read++] = ch;
2730 	}
2731 
2732 	return num_read;
2733 }
2734 
2735 static int __init samsung_early_console_setup(struct earlycon_device *device,
2736 					      const char *opt)
2737 {
2738 	if (!device->port.membase)
2739 		return -ENODEV;
2740 
2741 	device->con->write = samsung_early_write;
2742 	device->con->read = samsung_early_read;
2743 	return 0;
2744 }
2745 
2746 /* S3C2410 */
2747 static struct samsung_early_console_data s3c2410_early_console_data = {
2748 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2749 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
2750 };
2751 
2752 /* S3C64xx */
2753 static struct samsung_early_console_data s3c2440_early_console_data = {
2754 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2755 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
2756 };
2757 
2758 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2759 					      const char *opt)
2760 {
2761 	device->port.private_data = &s3c2440_early_console_data;
2762 	return samsung_early_console_setup(device, opt);
2763 }
2764 
2765 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2766 			s3c2440_early_console_setup);
2767 
2768 /* S5PV210, Exynos */
2769 static struct samsung_early_console_data s5pv210_early_console_data = {
2770 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2771 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
2772 };
2773 
2774 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2775 					      const char *opt)
2776 {
2777 	device->port.private_data = &s5pv210_early_console_data;
2778 	return samsung_early_console_setup(device, opt);
2779 }
2780 
2781 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2782 			s5pv210_early_console_setup);
2783 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2784 			s5pv210_early_console_setup);
2785 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
2786 			s5pv210_early_console_setup);
2787 
2788 /* Apple S5L */
2789 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
2790 						const char *opt)
2791 {
2792 	/* Close enough to S3C2410 for earlycon... */
2793 	device->port.private_data = &s3c2410_early_console_data;
2794 
2795 #ifdef CONFIG_ARM64
2796 	/* ... but we need to override the existing fixmap entry as nGnRnE */
2797 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
2798 		     __pgprot(PROT_DEVICE_nGnRnE));
2799 #endif
2800 	return samsung_early_console_setup(device, opt);
2801 }
2802 
2803 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
2804 #endif
2805 
2806 MODULE_ALIAS("platform:samsung-uart");
2807 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2808 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2809 MODULE_LICENSE("GPL v2");
2810