xref: /linux/drivers/tty/serial/samsung_tty.c (revision 2573c25e2c482b53b6e1142ff3cd28f6de13e659)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Note on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/console.h>
25 #include <linux/clk.h>
26 #include <linux/cpufreq.h>
27 #include <linux/delay.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/dmaengine.h>
30 #include <linux/init.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/math.h>
34 #include <linux/module.h>
35 #include <linux/of.h>
36 #include <linux/platform_device.h>
37 #include <linux/serial.h>
38 #include <linux/serial_core.h>
39 #include <linux/serial_s3c.h>
40 #include <linux/slab.h>
41 #include <linux/sysrq.h>
42 #include <linux/tty.h>
43 #include <linux/tty_flip.h>
44 #include <linux/types.h>
45 
46 #include <asm/irq.h>
47 
48 /* UART name and device definitions */
49 
50 #define S3C24XX_SERIAL_NAME	"ttySAC"
51 #define S3C24XX_SERIAL_MAJOR	204
52 #define S3C24XX_SERIAL_MINOR	64
53 
54 #ifdef CONFIG_ARM64
55 #define UART_NR			12
56 #else
57 #define UART_NR			CONFIG_SERIAL_SAMSUNG_UARTS
58 #endif
59 
60 #define S3C24XX_TX_PIO			1
61 #define S3C24XX_TX_DMA			2
62 #define S3C24XX_RX_PIO			1
63 #define S3C24XX_RX_DMA			2
64 
65 /* flag to ignore all characters coming in */
66 #define RXSTAT_DUMMY_READ (0x10000000)
67 
68 enum s3c24xx_port_type {
69 	TYPE_S3C6400,
70 	TYPE_APPLE_S5L,
71 };
72 
73 struct s3c24xx_uart_info {
74 	const char		*name;
75 	enum s3c24xx_port_type	type;
76 	unsigned int		port_type;
77 	unsigned int		fifosize;
78 	u32			rx_fifomask;
79 	u32			rx_fifoshift;
80 	u32			rx_fifofull;
81 	u32			tx_fifomask;
82 	u32			tx_fifoshift;
83 	u32			tx_fifofull;
84 	u32			clksel_mask;
85 	u32			clksel_shift;
86 	u32			ucon_mask;
87 	u8			def_clk_sel;
88 	u8			num_clks;
89 	u8			iotype;
90 
91 	/* uart port features */
92 	bool			has_divslot;
93 };
94 
95 struct s3c24xx_serial_drv_data {
96 	const struct s3c24xx_uart_info	info;
97 	const struct s3c2410_uartcfg	def_cfg;
98 	const unsigned int		fifosize[UART_NR];
99 };
100 
101 struct s3c24xx_uart_dma {
102 	unsigned int			rx_chan_id;
103 	unsigned int			tx_chan_id;
104 
105 	struct dma_slave_config		rx_conf;
106 	struct dma_slave_config		tx_conf;
107 
108 	struct dma_chan			*rx_chan;
109 	struct dma_chan			*tx_chan;
110 
111 	dma_addr_t			rx_addr;
112 	dma_addr_t			tx_addr;
113 
114 	dma_cookie_t			rx_cookie;
115 	dma_cookie_t			tx_cookie;
116 
117 	char				*rx_buf;
118 
119 	dma_addr_t			tx_transfer_addr;
120 
121 	size_t				rx_size;
122 	size_t				tx_size;
123 
124 	struct dma_async_tx_descriptor	*tx_desc;
125 	struct dma_async_tx_descriptor	*rx_desc;
126 
127 	int				tx_bytes_requested;
128 	int				rx_bytes_requested;
129 };
130 
131 struct s3c24xx_uart_port {
132 	unsigned char			rx_enabled;
133 	unsigned char			tx_enabled;
134 	unsigned int			pm_level;
135 	unsigned long			baudclk_rate;
136 	unsigned int			min_dma_size;
137 
138 	unsigned int			rx_irq;
139 	unsigned int			tx_irq;
140 
141 	unsigned int			tx_in_progress;
142 	unsigned int			tx_mode;
143 	unsigned int			rx_mode;
144 
145 	const struct s3c24xx_uart_info	*info;
146 	struct clk			*clk;
147 	struct clk			*baudclk;
148 	struct uart_port		port;
149 	const struct s3c24xx_serial_drv_data	*drv_data;
150 
151 	/* reference to platform data */
152 	const struct s3c2410_uartcfg	*cfg;
153 
154 	struct s3c24xx_uart_dma		*dma;
155 };
156 
157 static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport);
158 
159 /* conversion functions */
160 
161 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
162 
163 /* register access controls */
164 
165 #define portaddr(port, reg) ((port)->membase + (reg))
166 #define portaddrl(port, reg) \
167 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
168 
169 static u32 rd_reg(const struct uart_port *port, u32 reg)
170 {
171 	switch (port->iotype) {
172 	case UPIO_MEM:
173 		return readb_relaxed(portaddr(port, reg));
174 	case UPIO_MEM32:
175 		return readl_relaxed(portaddr(port, reg));
176 	default:
177 		return 0;
178 	}
179 	return 0;
180 }
181 
182 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
183 
184 static void wr_reg(const struct uart_port *port, u32 reg, u32 val)
185 {
186 	switch (port->iotype) {
187 	case UPIO_MEM:
188 		writeb_relaxed(val, portaddr(port, reg));
189 		break;
190 	case UPIO_MEM32:
191 		writel_relaxed(val, portaddr(port, reg));
192 		break;
193 	}
194 }
195 
196 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
197 
198 /* Byte-order aware bit setting/clearing functions. */
199 
200 static inline void s3c24xx_set_bit(const struct uart_port *port, int idx,
201 				   u32 reg)
202 {
203 	unsigned long flags;
204 	u32 val;
205 
206 	local_irq_save(flags);
207 	val = rd_regl(port, reg);
208 	val |= (1 << idx);
209 	wr_regl(port, reg, val);
210 	local_irq_restore(flags);
211 }
212 
213 static inline void s3c24xx_clear_bit(const struct uart_port *port, int idx,
214 				     u32 reg)
215 {
216 	unsigned long flags;
217 	u32 val;
218 
219 	local_irq_save(flags);
220 	val = rd_regl(port, reg);
221 	val &= ~(1 << idx);
222 	wr_regl(port, reg, val);
223 	local_irq_restore(flags);
224 }
225 
226 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
227 {
228 	return container_of(port, struct s3c24xx_uart_port, port);
229 }
230 
231 /* translate a port to the device name */
232 
233 static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
234 {
235 	return to_platform_device(port->dev)->name;
236 }
237 
238 static bool s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
239 {
240 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
241 }
242 
243 static void s3c24xx_serial_rx_enable(struct uart_port *port)
244 {
245 	struct s3c24xx_uart_port *ourport = to_ourport(port);
246 	unsigned long flags;
247 	int count = 10000;
248 	u32 ucon, ufcon;
249 
250 	uart_port_lock_irqsave(port, &flags);
251 
252 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
253 		udelay(100);
254 
255 	ufcon = rd_regl(port, S3C2410_UFCON);
256 	ufcon |= S3C2410_UFCON_RESETRX;
257 	wr_regl(port, S3C2410_UFCON, ufcon);
258 
259 	ucon = rd_regl(port, S3C2410_UCON);
260 	ucon |= S3C2410_UCON_RXIRQMODE;
261 	wr_regl(port, S3C2410_UCON, ucon);
262 
263 	ourport->rx_enabled = 1;
264 	uart_port_unlock_irqrestore(port, flags);
265 }
266 
267 static void s3c24xx_serial_rx_disable(struct uart_port *port)
268 {
269 	struct s3c24xx_uart_port *ourport = to_ourport(port);
270 	unsigned long flags;
271 	u32 ucon;
272 
273 	uart_port_lock_irqsave(port, &flags);
274 
275 	ucon = rd_regl(port, S3C2410_UCON);
276 	ucon &= ~S3C2410_UCON_RXIRQMODE;
277 	wr_regl(port, S3C2410_UCON, ucon);
278 
279 	ourport->rx_enabled = 0;
280 	uart_port_unlock_irqrestore(port, flags);
281 }
282 
283 static void s3c24xx_serial_stop_tx(struct uart_port *port)
284 {
285 	struct s3c24xx_uart_port *ourport = to_ourport(port);
286 	struct s3c24xx_uart_dma *dma = ourport->dma;
287 	struct dma_tx_state state;
288 	int count;
289 
290 	if (!ourport->tx_enabled)
291 		return;
292 
293 	switch (ourport->info->type) {
294 	case TYPE_S3C6400:
295 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
296 		break;
297 	case TYPE_APPLE_S5L:
298 		s3c24xx_clear_bit(port, APPLE_S5L_UCON_TXTHRESH_ENA, S3C2410_UCON);
299 		break;
300 	default:
301 		disable_irq_nosync(ourport->tx_irq);
302 		break;
303 	}
304 
305 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
306 		dmaengine_pause(dma->tx_chan);
307 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
308 		dmaengine_terminate_all(dma->tx_chan);
309 		dma_sync_single_for_cpu(dma->tx_chan->device->dev,
310 					dma->tx_transfer_addr, dma->tx_size,
311 					DMA_TO_DEVICE);
312 		async_tx_ack(dma->tx_desc);
313 		count = dma->tx_bytes_requested - state.residue;
314 		uart_xmit_advance(port, count);
315 	}
316 
317 	ourport->tx_enabled = 0;
318 	ourport->tx_in_progress = 0;
319 
320 	if (port->flags & UPF_CONS_FLOW)
321 		s3c24xx_serial_rx_enable(port);
322 
323 	ourport->tx_mode = 0;
324 }
325 
326 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
327 
328 static void s3c24xx_serial_tx_dma_complete(void *args)
329 {
330 	struct s3c24xx_uart_port *ourport = args;
331 	struct uart_port *port = &ourport->port;
332 	struct circ_buf *xmit = &port->state->xmit;
333 	struct s3c24xx_uart_dma *dma = ourport->dma;
334 	struct dma_tx_state state;
335 	unsigned long flags;
336 	int count;
337 
338 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
339 	count = dma->tx_bytes_requested - state.residue;
340 	async_tx_ack(dma->tx_desc);
341 
342 	dma_sync_single_for_cpu(dma->tx_chan->device->dev,
343 				dma->tx_transfer_addr, dma->tx_size,
344 				DMA_TO_DEVICE);
345 
346 	uart_port_lock_irqsave(port, &flags);
347 
348 	uart_xmit_advance(port, count);
349 	ourport->tx_in_progress = 0;
350 
351 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
352 		uart_write_wakeup(port);
353 
354 	s3c24xx_serial_start_next_tx(ourport);
355 	uart_port_unlock_irqrestore(port, flags);
356 }
357 
358 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
359 {
360 	const struct uart_port *port = &ourport->port;
361 	u32 ucon;
362 
363 	/* Mask Tx interrupt */
364 	switch (ourport->info->type) {
365 	case TYPE_S3C6400:
366 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
367 		break;
368 	case TYPE_APPLE_S5L:
369 		WARN_ON(1); // No DMA
370 		break;
371 	default:
372 		disable_irq_nosync(ourport->tx_irq);
373 		break;
374 	}
375 
376 	/* Enable tx dma mode */
377 	ucon = rd_regl(port, S3C2410_UCON);
378 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
379 	ucon |= S3C64XX_UCON_TXBURST_1;
380 	ucon |= S3C64XX_UCON_TXMODE_DMA;
381 	wr_regl(port,  S3C2410_UCON, ucon);
382 
383 	ourport->tx_mode = S3C24XX_TX_DMA;
384 }
385 
386 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
387 {
388 	const struct uart_port *port = &ourport->port;
389 	u32 ucon, ufcon;
390 
391 	/* Set ufcon txtrig */
392 	ourport->tx_in_progress = S3C24XX_TX_PIO;
393 	ufcon = rd_regl(port, S3C2410_UFCON);
394 	wr_regl(port,  S3C2410_UFCON, ufcon);
395 
396 	/* Enable tx pio mode */
397 	ucon = rd_regl(port, S3C2410_UCON);
398 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
399 	ucon |= S3C64XX_UCON_TXMODE_CPU;
400 	wr_regl(port,  S3C2410_UCON, ucon);
401 
402 	/* Unmask Tx interrupt */
403 	switch (ourport->info->type) {
404 	case TYPE_S3C6400:
405 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
406 				  S3C64XX_UINTM);
407 		break;
408 	case TYPE_APPLE_S5L:
409 		ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
410 		wr_regl(port, S3C2410_UCON, ucon);
411 		break;
412 	default:
413 		enable_irq(ourport->tx_irq);
414 		break;
415 	}
416 
417 	ourport->tx_mode = S3C24XX_TX_PIO;
418 
419 	/*
420 	 * The Apple version only has edge triggered TX IRQs, so we need
421 	 * to kick off the process by sending some characters here.
422 	 */
423 	if (ourport->info->type == TYPE_APPLE_S5L)
424 		s3c24xx_serial_tx_chars(ourport);
425 }
426 
427 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
428 {
429 	if (ourport->tx_mode != S3C24XX_TX_PIO)
430 		enable_tx_pio(ourport);
431 }
432 
433 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
434 				      unsigned int count)
435 {
436 	struct uart_port *port = &ourport->port;
437 	struct circ_buf *xmit = &port->state->xmit;
438 	struct s3c24xx_uart_dma *dma = ourport->dma;
439 
440 	if (ourport->tx_mode != S3C24XX_TX_DMA)
441 		enable_tx_dma(ourport);
442 
443 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
444 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
445 
446 	dma_sync_single_for_device(dma->tx_chan->device->dev,
447 				   dma->tx_transfer_addr, dma->tx_size,
448 				   DMA_TO_DEVICE);
449 
450 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
451 				dma->tx_transfer_addr, dma->tx_size,
452 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
453 	if (!dma->tx_desc) {
454 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
455 		return -EIO;
456 	}
457 
458 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
459 	dma->tx_desc->callback_param = ourport;
460 	dma->tx_bytes_requested = dma->tx_size;
461 
462 	ourport->tx_in_progress = S3C24XX_TX_DMA;
463 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
464 	dma_async_issue_pending(dma->tx_chan);
465 	return 0;
466 }
467 
468 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
469 {
470 	struct uart_port *port = &ourport->port;
471 	struct circ_buf *xmit = &port->state->xmit;
472 	unsigned long count;
473 
474 	/* Get data size up to the end of buffer */
475 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
476 
477 	if (!count) {
478 		s3c24xx_serial_stop_tx(port);
479 		return;
480 	}
481 
482 	if (!ourport->dma || !ourport->dma->tx_chan ||
483 	    count < ourport->min_dma_size ||
484 	    xmit->tail & (dma_get_cache_alignment() - 1))
485 		s3c24xx_serial_start_tx_pio(ourport);
486 	else
487 		s3c24xx_serial_start_tx_dma(ourport, count);
488 }
489 
490 static void s3c24xx_serial_start_tx(struct uart_port *port)
491 {
492 	struct s3c24xx_uart_port *ourport = to_ourport(port);
493 	struct circ_buf *xmit = &port->state->xmit;
494 
495 	if (!ourport->tx_enabled) {
496 		if (port->flags & UPF_CONS_FLOW)
497 			s3c24xx_serial_rx_disable(port);
498 
499 		ourport->tx_enabled = 1;
500 		if (!ourport->dma || !ourport->dma->tx_chan)
501 			s3c24xx_serial_start_tx_pio(ourport);
502 	}
503 
504 	if (ourport->dma && ourport->dma->tx_chan) {
505 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
506 			s3c24xx_serial_start_next_tx(ourport);
507 	}
508 }
509 
510 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
511 		struct tty_port *tty, int count)
512 {
513 	struct s3c24xx_uart_dma *dma = ourport->dma;
514 	int copied;
515 
516 	if (!count)
517 		return;
518 
519 	dma_sync_single_for_cpu(dma->rx_chan->device->dev, dma->rx_addr,
520 				dma->rx_size, DMA_FROM_DEVICE);
521 
522 	ourport->port.icount.rx += count;
523 	if (!tty) {
524 		dev_err(ourport->port.dev, "No tty port\n");
525 		return;
526 	}
527 	copied = tty_insert_flip_string(tty,
528 			((unsigned char *)(ourport->dma->rx_buf)), count);
529 	if (copied != count) {
530 		WARN_ON(1);
531 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
532 	}
533 }
534 
535 static void s3c24xx_serial_stop_rx(struct uart_port *port)
536 {
537 	struct s3c24xx_uart_port *ourport = to_ourport(port);
538 	struct s3c24xx_uart_dma *dma = ourport->dma;
539 	struct tty_port *t = &port->state->port;
540 	struct dma_tx_state state;
541 	enum dma_status dma_status;
542 	unsigned int received;
543 
544 	if (ourport->rx_enabled) {
545 		dev_dbg(port->dev, "stopping rx\n");
546 		switch (ourport->info->type) {
547 		case TYPE_S3C6400:
548 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
549 					S3C64XX_UINTM);
550 			break;
551 		case TYPE_APPLE_S5L:
552 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
553 			s3c24xx_clear_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
554 			break;
555 		default:
556 			disable_irq_nosync(ourport->rx_irq);
557 			break;
558 		}
559 		ourport->rx_enabled = 0;
560 	}
561 	if (dma && dma->rx_chan) {
562 		dmaengine_pause(dma->tx_chan);
563 		dma_status = dmaengine_tx_status(dma->rx_chan,
564 				dma->rx_cookie, &state);
565 		if (dma_status == DMA_IN_PROGRESS ||
566 			dma_status == DMA_PAUSED) {
567 			received = dma->rx_bytes_requested - state.residue;
568 			dmaengine_terminate_all(dma->rx_chan);
569 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
570 		}
571 	}
572 }
573 
574 static inline const struct s3c24xx_uart_info
575 	*s3c24xx_port_to_info(struct uart_port *port)
576 {
577 	return to_ourport(port)->info;
578 }
579 
580 static inline const struct s3c2410_uartcfg
581 	*s3c24xx_port_to_cfg(const struct uart_port *port)
582 {
583 	const struct s3c24xx_uart_port *ourport;
584 
585 	if (port->dev == NULL)
586 		return NULL;
587 
588 	ourport = container_of(port, struct s3c24xx_uart_port, port);
589 	return ourport->cfg;
590 }
591 
592 static unsigned int
593 s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport, u32 ufstat)
594 {
595 	const struct s3c24xx_uart_info *info = ourport->info;
596 
597 	if (ufstat & info->rx_fifofull)
598 		return ourport->port.fifosize;
599 
600 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
601 }
602 
603 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
604 static void s3c24xx_serial_rx_dma_complete(void *args)
605 {
606 	struct s3c24xx_uart_port *ourport = args;
607 	struct uart_port *port = &ourport->port;
608 
609 	struct s3c24xx_uart_dma *dma = ourport->dma;
610 	struct tty_port *t = &port->state->port;
611 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
612 
613 	struct dma_tx_state state;
614 	unsigned long flags;
615 	int received;
616 
617 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
618 	received  = dma->rx_bytes_requested - state.residue;
619 	async_tx_ack(dma->rx_desc);
620 
621 	uart_port_lock_irqsave(port, &flags);
622 
623 	if (received)
624 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
625 
626 	if (tty) {
627 		tty_flip_buffer_push(t);
628 		tty_kref_put(tty);
629 	}
630 
631 	s3c64xx_start_rx_dma(ourport);
632 
633 	uart_port_unlock_irqrestore(port, flags);
634 }
635 
636 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
637 {
638 	struct s3c24xx_uart_dma *dma = ourport->dma;
639 
640 	dma_sync_single_for_device(dma->rx_chan->device->dev, dma->rx_addr,
641 				   dma->rx_size, DMA_FROM_DEVICE);
642 
643 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
644 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
645 				DMA_PREP_INTERRUPT);
646 	if (!dma->rx_desc) {
647 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
648 		return;
649 	}
650 
651 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
652 	dma->rx_desc->callback_param = ourport;
653 	dma->rx_bytes_requested = dma->rx_size;
654 
655 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
656 	dma_async_issue_pending(dma->rx_chan);
657 }
658 
659 /* ? - where has parity gone?? */
660 #define S3C2410_UERSTAT_PARITY (0x1000)
661 
662 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
663 {
664 	struct uart_port *port = &ourport->port;
665 	u32 ucon;
666 
667 	/* set Rx mode to DMA mode */
668 	ucon = rd_regl(port, S3C2410_UCON);
669 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
670 			S3C64XX_UCON_TIMEOUT_MASK |
671 			S3C64XX_UCON_EMPTYINT_EN |
672 			S3C64XX_UCON_DMASUS_EN |
673 			S3C64XX_UCON_TIMEOUT_EN |
674 			S3C64XX_UCON_RXMODE_MASK);
675 	ucon |= S3C64XX_UCON_RXBURST_1 |
676 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
677 			S3C64XX_UCON_EMPTYINT_EN |
678 			S3C64XX_UCON_TIMEOUT_EN |
679 			S3C64XX_UCON_RXMODE_DMA;
680 	wr_regl(port, S3C2410_UCON, ucon);
681 
682 	ourport->rx_mode = S3C24XX_RX_DMA;
683 }
684 
685 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
686 {
687 	struct uart_port *port = &ourport->port;
688 	u32 ucon;
689 
690 	/* set Rx mode to DMA mode */
691 	ucon = rd_regl(port, S3C2410_UCON);
692 	ucon &= ~S3C64XX_UCON_RXMODE_MASK;
693 	ucon |= S3C64XX_UCON_RXMODE_CPU;
694 
695 	/* Apple types use these bits for IRQ masks */
696 	if (ourport->info->type != TYPE_APPLE_S5L) {
697 		ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
698 				S3C64XX_UCON_EMPTYINT_EN |
699 				S3C64XX_UCON_DMASUS_EN |
700 				S3C64XX_UCON_TIMEOUT_EN);
701 		ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
702 				S3C64XX_UCON_TIMEOUT_EN;
703 	}
704 	wr_regl(port, S3C2410_UCON, ucon);
705 
706 	ourport->rx_mode = S3C24XX_RX_PIO;
707 }
708 
709 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
710 
711 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
712 {
713 	struct s3c24xx_uart_port *ourport = dev_id;
714 	struct uart_port *port = &ourport->port;
715 	struct s3c24xx_uart_dma *dma = ourport->dma;
716 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
717 	struct tty_port *t = &port->state->port;
718 	struct dma_tx_state state;
719 	unsigned int received;
720 	u32 utrstat;
721 
722 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
723 	rd_regl(port, S3C2410_UFSTAT);
724 
725 	uart_port_lock(port);
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 	uart_port_unlock(port);
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 max_count = port->fifosize;
763 	unsigned int fifocnt = 0;
764 	u32 ufcon, ufstat, uerstat;
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 			bool 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 	uart_port_lock(port);
853 	s3c24xx_serial_rx_drain_fifo(ourport);
854 	uart_port_unlock(port);
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 	uart_port_lock(port);
936 
937 	s3c24xx_serial_tx_chars(ourport);
938 
939 	uart_port_unlock(port);
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 	u32 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 	u32 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 	u32 ufstat = rd_regl(port, S3C2410_UFSTAT);
987 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
988 
989 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
990 		if ((ufstat & info->tx_fifomask) ||
991 		    (ufstat & info->tx_fifofull))
992 			return 0;
993 		return TIOCSER_TEMT;
994 	}
995 
996 	return s3c24xx_serial_txempty_nofifo(port) ? TIOCSER_TEMT : 0;
997 }
998 
999 /* no modem control lines */
1000 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
1001 {
1002 	u32 umstat = rd_reg(port, S3C2410_UMSTAT);
1003 
1004 	if (umstat & S3C2410_UMSTAT_CTS)
1005 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
1006 	else
1007 		return TIOCM_CAR | TIOCM_DSR;
1008 }
1009 
1010 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
1011 {
1012 	u32 umcon = rd_regl(port, S3C2410_UMCON);
1013 	u32 ucon = rd_regl(port, S3C2410_UCON);
1014 
1015 	if (mctrl & TIOCM_RTS)
1016 		umcon |= S3C2410_UMCOM_RTS_LOW;
1017 	else
1018 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
1019 
1020 	wr_regl(port, S3C2410_UMCON, umcon);
1021 
1022 	if (mctrl & TIOCM_LOOP)
1023 		ucon |= S3C2410_UCON_LOOPBACK;
1024 	else
1025 		ucon &= ~S3C2410_UCON_LOOPBACK;
1026 
1027 	wr_regl(port, S3C2410_UCON, ucon);
1028 }
1029 
1030 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
1031 {
1032 	unsigned long flags;
1033 	u32 ucon;
1034 
1035 	uart_port_lock_irqsave(port, &flags);
1036 
1037 	ucon = rd_regl(port, S3C2410_UCON);
1038 
1039 	if (break_state)
1040 		ucon |= S3C2410_UCON_SBREAK;
1041 	else
1042 		ucon &= ~S3C2410_UCON_SBREAK;
1043 
1044 	wr_regl(port, S3C2410_UCON, ucon);
1045 
1046 	uart_port_unlock_irqrestore(port, flags);
1047 }
1048 
1049 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
1050 {
1051 	struct s3c24xx_uart_dma	*dma = p->dma;
1052 	struct dma_slave_caps dma_caps;
1053 	const char *reason = NULL;
1054 	int ret;
1055 
1056 	/* Default slave configuration parameters */
1057 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
1058 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1059 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
1060 	dma->rx_conf.src_maxburst	= 1;
1061 
1062 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
1063 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
1064 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
1065 	dma->tx_conf.dst_maxburst	= 1;
1066 
1067 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1068 
1069 	if (IS_ERR(dma->rx_chan)) {
1070 		reason = "DMA RX channel request failed";
1071 		ret = PTR_ERR(dma->rx_chan);
1072 		goto err_warn;
1073 	}
1074 
1075 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1076 	if (ret < 0 ||
1077 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1078 		reason = "insufficient DMA RX engine capabilities";
1079 		ret = -EOPNOTSUPP;
1080 		goto err_release_rx;
1081 	}
1082 
1083 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1084 
1085 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1086 	if (IS_ERR(dma->tx_chan)) {
1087 		reason = "DMA TX channel request failed";
1088 		ret = PTR_ERR(dma->tx_chan);
1089 		goto err_release_rx;
1090 	}
1091 
1092 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1093 	if (ret < 0 ||
1094 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1095 		reason = "insufficient DMA TX engine capabilities";
1096 		ret = -EOPNOTSUPP;
1097 		goto err_release_tx;
1098 	}
1099 
1100 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1101 
1102 	/* RX buffer */
1103 	dma->rx_size = PAGE_SIZE;
1104 
1105 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1106 	if (!dma->rx_buf) {
1107 		ret = -ENOMEM;
1108 		goto err_release_tx;
1109 	}
1110 
1111 	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
1112 				      dma->rx_size, DMA_FROM_DEVICE);
1113 	if (dma_mapping_error(dma->rx_chan->device->dev, dma->rx_addr)) {
1114 		reason = "DMA mapping error for RX buffer";
1115 		ret = -EIO;
1116 		goto err_free_rx;
1117 	}
1118 
1119 	/* TX buffer */
1120 	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
1121 				      p->port.state->xmit.buf, UART_XMIT_SIZE,
1122 				      DMA_TO_DEVICE);
1123 	if (dma_mapping_error(dma->tx_chan->device->dev, dma->tx_addr)) {
1124 		reason = "DMA mapping error for TX buffer";
1125 		ret = -EIO;
1126 		goto err_unmap_rx;
1127 	}
1128 
1129 	return 0;
1130 
1131 err_unmap_rx:
1132 	dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1133 			 dma->rx_size, DMA_FROM_DEVICE);
1134 err_free_rx:
1135 	kfree(dma->rx_buf);
1136 err_release_tx:
1137 	dma_release_channel(dma->tx_chan);
1138 err_release_rx:
1139 	dma_release_channel(dma->rx_chan);
1140 err_warn:
1141 	if (reason)
1142 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1143 	return ret;
1144 }
1145 
1146 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1147 {
1148 	struct s3c24xx_uart_dma	*dma = p->dma;
1149 
1150 	if (dma->rx_chan) {
1151 		dmaengine_terminate_all(dma->rx_chan);
1152 		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
1153 				 dma->rx_size, DMA_FROM_DEVICE);
1154 		kfree(dma->rx_buf);
1155 		dma_release_channel(dma->rx_chan);
1156 		dma->rx_chan = NULL;
1157 	}
1158 
1159 	if (dma->tx_chan) {
1160 		dmaengine_terminate_all(dma->tx_chan);
1161 		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
1162 				 UART_XMIT_SIZE, DMA_TO_DEVICE);
1163 		dma_release_channel(dma->tx_chan);
1164 		dma->tx_chan = NULL;
1165 	}
1166 }
1167 
1168 static void s3c64xx_serial_shutdown(struct uart_port *port)
1169 {
1170 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1171 
1172 	ourport->tx_enabled = 0;
1173 	ourport->tx_mode = 0;
1174 	ourport->rx_enabled = 0;
1175 
1176 	free_irq(port->irq, ourport);
1177 
1178 	wr_regl(port, S3C64XX_UINTP, 0xf);
1179 	wr_regl(port, S3C64XX_UINTM, 0xf);
1180 
1181 	if (ourport->dma)
1182 		s3c24xx_serial_release_dma(ourport);
1183 
1184 	ourport->tx_in_progress = 0;
1185 }
1186 
1187 static void apple_s5l_serial_shutdown(struct uart_port *port)
1188 {
1189 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1190 
1191 	u32 ucon;
1192 
1193 	ucon = rd_regl(port, S3C2410_UCON);
1194 	ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1195 		  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1196 		  APPLE_S5L_UCON_RXTO_ENA_MSK);
1197 	wr_regl(port, S3C2410_UCON, ucon);
1198 
1199 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1200 
1201 	free_irq(port->irq, ourport);
1202 
1203 	ourport->tx_enabled = 0;
1204 	ourport->tx_mode = 0;
1205 	ourport->rx_enabled = 0;
1206 
1207 	if (ourport->dma)
1208 		s3c24xx_serial_release_dma(ourport);
1209 
1210 	ourport->tx_in_progress = 0;
1211 }
1212 
1213 static int s3c64xx_serial_startup(struct uart_port *port)
1214 {
1215 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1216 	unsigned long flags;
1217 	u32 ufcon;
1218 	int ret;
1219 
1220 	wr_regl(port, S3C64XX_UINTM, 0xf);
1221 	if (ourport->dma) {
1222 		ret = s3c24xx_serial_request_dma(ourport);
1223 		if (ret < 0) {
1224 			devm_kfree(port->dev, ourport->dma);
1225 			ourport->dma = NULL;
1226 		}
1227 	}
1228 
1229 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1230 			  s3c24xx_serial_portname(port), ourport);
1231 	if (ret) {
1232 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1233 		return ret;
1234 	}
1235 
1236 	/* For compatibility with s3c24xx Soc's */
1237 	ourport->rx_enabled = 1;
1238 	ourport->tx_enabled = 0;
1239 
1240 	uart_port_lock_irqsave(port, &flags);
1241 
1242 	ufcon = rd_regl(port, S3C2410_UFCON);
1243 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1244 	if (!uart_console(port))
1245 		ufcon |= S3C2410_UFCON_RESETTX;
1246 	wr_regl(port, S3C2410_UFCON, ufcon);
1247 
1248 	enable_rx_pio(ourport);
1249 
1250 	uart_port_unlock_irqrestore(port, flags);
1251 
1252 	/* Enable Rx Interrupt */
1253 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1254 
1255 	return ret;
1256 }
1257 
1258 static int apple_s5l_serial_startup(struct uart_port *port)
1259 {
1260 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1261 	unsigned long flags;
1262 	u32 ufcon;
1263 	int ret;
1264 
1265 	wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1266 
1267 	ret = request_irq(port->irq, apple_serial_handle_irq, 0,
1268 			  s3c24xx_serial_portname(port), ourport);
1269 	if (ret) {
1270 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1271 		return ret;
1272 	}
1273 
1274 	/* For compatibility with s3c24xx Soc's */
1275 	ourport->rx_enabled = 1;
1276 	ourport->tx_enabled = 0;
1277 
1278 	uart_port_lock_irqsave(port, &flags);
1279 
1280 	ufcon = rd_regl(port, S3C2410_UFCON);
1281 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1282 	if (!uart_console(port))
1283 		ufcon |= S3C2410_UFCON_RESETTX;
1284 	wr_regl(port, S3C2410_UFCON, ufcon);
1285 
1286 	enable_rx_pio(ourport);
1287 
1288 	uart_port_unlock_irqrestore(port, flags);
1289 
1290 	/* Enable Rx Interrupt */
1291 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
1292 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTO_ENA, S3C2410_UCON);
1293 
1294 	return ret;
1295 }
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 u8 s3c24xx_serial_getsource(struct uart_port *port)
1343 {
1344 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1345 	u32 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, u8 clk_sel)
1356 {
1357 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1358 	u32 ucon;
1359 
1360 	if (info->num_clks == 1)
1361 		return;
1362 
1363 	ucon = rd_regl(port, S3C2410_UCON);
1364 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1365 		return;
1366 
1367 	ucon &= ~info->clksel_mask;
1368 	ucon |= clk_sel << info->clksel_shift;
1369 	wr_regl(port, S3C2410_UCON, ucon);
1370 }
1371 
1372 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1373 			unsigned int req_baud, struct clk **best_clk,
1374 			u8 *clk_num)
1375 {
1376 	const struct s3c24xx_uart_info *info = ourport->info;
1377 	struct clk *clk;
1378 	unsigned long rate;
1379 	unsigned int baud, quot, best_quot = 0;
1380 	char clkname[MAX_CLK_NAME_LENGTH];
1381 	int calc_deviation, deviation = (1 << 30) - 1;
1382 	u8 cnt;
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;
1476 	unsigned int udivslot = 0;
1477 	u32 ulcon, umcon;
1478 	u8 clk_sel = 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 {
1742 	struct uart_port *port = &s3c24xx_serial_ports[index].port;
1743 
1744 	spin_lock_init(&port->lock);
1745 
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 	u32 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 	struct clk *clk;
1780 	int ret;
1781 	u8 clk_sel, clk_num;
1782 
1783 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1784 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1785 		if (!(clk_sel & (1 << clk_num)))
1786 			continue;
1787 
1788 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1789 		clk = clk_get(dev, clk_name);
1790 		if (IS_ERR(clk))
1791 			continue;
1792 
1793 		ret = clk_prepare_enable(clk);
1794 		if (ret) {
1795 			clk_put(clk);
1796 			continue;
1797 		}
1798 
1799 		ourport->baudclk = clk;
1800 		ourport->baudclk_rate = clk_get_rate(clk);
1801 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1802 
1803 		return 0;
1804 	}
1805 
1806 	return -EINVAL;
1807 }
1808 
1809 /* s3c24xx_serial_init_port
1810  *
1811  * initialise a single serial port from the platform device given
1812  */
1813 
1814 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1815 				    struct platform_device *platdev)
1816 {
1817 	struct uart_port *port = &ourport->port;
1818 	const struct s3c2410_uartcfg *cfg = ourport->cfg;
1819 	struct resource *res;
1820 	int ret;
1821 
1822 	if (platdev == NULL)
1823 		return -ENODEV;
1824 
1825 	if (port->mapbase != 0)
1826 		return -EINVAL;
1827 
1828 	/* setup info for port */
1829 	port->dev	= &platdev->dev;
1830 
1831 	port->uartclk = 1;
1832 
1833 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1834 		dev_dbg(port->dev, "enabling flow control\n");
1835 		port->flags |= UPF_CONS_FLOW;
1836 	}
1837 
1838 	/* sort our the physical and virtual addresses for each UART */
1839 
1840 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1841 	if (res == NULL) {
1842 		dev_err(port->dev, "failed to find memory resource for uart\n");
1843 		return -EINVAL;
1844 	}
1845 
1846 	dev_dbg(port->dev, "resource %pR)\n", res);
1847 
1848 	port->membase = devm_ioremap_resource(port->dev, res);
1849 	if (IS_ERR(port->membase)) {
1850 		dev_err(port->dev, "failed to remap controller address\n");
1851 		return -EBUSY;
1852 	}
1853 
1854 	port->mapbase = res->start;
1855 	ret = platform_get_irq(platdev, 0);
1856 	if (ret < 0) {
1857 		port->irq = 0;
1858 	} else {
1859 		port->irq = ret;
1860 		ourport->rx_irq = ret;
1861 		ourport->tx_irq = ret + 1;
1862 	}
1863 
1864 	/*
1865 	 * DMA is currently supported only on DT platforms, if DMA properties
1866 	 * are specified.
1867 	 */
1868 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1869 						     "dmas", NULL)) {
1870 		ourport->dma = devm_kzalloc(port->dev,
1871 					    sizeof(*ourport->dma),
1872 					    GFP_KERNEL);
1873 		if (!ourport->dma) {
1874 			ret = -ENOMEM;
1875 			goto err;
1876 		}
1877 	}
1878 
1879 	ourport->clk	= clk_get(&platdev->dev, "uart");
1880 	if (IS_ERR(ourport->clk)) {
1881 		pr_err("%s: Controller clock not found\n",
1882 				dev_name(&platdev->dev));
1883 		ret = PTR_ERR(ourport->clk);
1884 		goto err;
1885 	}
1886 
1887 	ret = clk_prepare_enable(ourport->clk);
1888 	if (ret) {
1889 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1890 		clk_put(ourport->clk);
1891 		goto err;
1892 	}
1893 
1894 	ret = s3c24xx_serial_enable_baudclk(ourport);
1895 	if (ret)
1896 		pr_warn("uart: failed to enable baudclk\n");
1897 
1898 	/* Keep all interrupts masked and cleared */
1899 	switch (ourport->info->type) {
1900 	case TYPE_S3C6400:
1901 		wr_regl(port, S3C64XX_UINTM, 0xf);
1902 		wr_regl(port, S3C64XX_UINTP, 0xf);
1903 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1904 		break;
1905 	case TYPE_APPLE_S5L: {
1906 		u32 ucon;
1907 
1908 		ucon = rd_regl(port, S3C2410_UCON);
1909 		ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
1910 			APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
1911 			APPLE_S5L_UCON_RXTO_ENA_MSK);
1912 		wr_regl(port, S3C2410_UCON, ucon);
1913 
1914 		wr_regl(port, S3C2410_UTRSTAT, APPLE_S5L_UTRSTAT_ALL_FLAGS);
1915 		break;
1916 	}
1917 	default:
1918 		break;
1919 	}
1920 
1921 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1922 		&port->mapbase, port->membase, port->irq,
1923 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
1924 
1925 	/* reset the fifos (and setup the uart) */
1926 	s3c24xx_serial_resetport(port, cfg);
1927 
1928 	return 0;
1929 
1930 err:
1931 	port->mapbase = 0;
1932 	return ret;
1933 }
1934 
1935 /* Device driver serial port probe */
1936 
1937 static int probe_index;
1938 
1939 static inline const struct s3c24xx_serial_drv_data *
1940 s3c24xx_get_driver_data(struct platform_device *pdev)
1941 {
1942 	if (dev_of_node(&pdev->dev))
1943 		return of_device_get_match_data(&pdev->dev);
1944 
1945 	return (struct s3c24xx_serial_drv_data *)
1946 			platform_get_device_id(pdev)->driver_data;
1947 }
1948 
1949 static int s3c24xx_serial_probe(struct platform_device *pdev)
1950 {
1951 	struct device_node *np = pdev->dev.of_node;
1952 	struct s3c24xx_uart_port *ourport;
1953 	int index = probe_index;
1954 	int ret, prop = 0, fifosize_prop = 1;
1955 
1956 	if (np) {
1957 		ret = of_alias_get_id(np, "serial");
1958 		if (ret >= 0)
1959 			index = ret;
1960 	}
1961 
1962 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
1963 		dev_err(&pdev->dev, "serial%d out of range\n", index);
1964 		return -EINVAL;
1965 	}
1966 	ourport = &s3c24xx_serial_ports[index];
1967 
1968 	s3c24xx_serial_init_port_default(index);
1969 
1970 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
1971 	if (!ourport->drv_data) {
1972 		dev_err(&pdev->dev, "could not find driver data\n");
1973 		return -ENODEV;
1974 	}
1975 
1976 	ourport->baudclk = ERR_PTR(-EINVAL);
1977 	ourport->info = &ourport->drv_data->info;
1978 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
1979 			dev_get_platdata(&pdev->dev) :
1980 			&ourport->drv_data->def_cfg;
1981 
1982 	switch (ourport->info->type) {
1983 	case TYPE_S3C6400:
1984 		ourport->port.ops = &s3c64xx_serial_ops;
1985 		break;
1986 	case TYPE_APPLE_S5L:
1987 		ourport->port.ops = &apple_s5l_serial_ops;
1988 		break;
1989 	}
1990 
1991 	ourport->port.iotype = ourport->info->iotype;
1992 
1993 	if (np) {
1994 		fifosize_prop = of_property_read_u32(np, "samsung,uart-fifosize",
1995 				&ourport->port.fifosize);
1996 
1997 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
1998 			switch (prop) {
1999 			case 1:
2000 				ourport->port.iotype = UPIO_MEM;
2001 				break;
2002 			case 4:
2003 				ourport->port.iotype = UPIO_MEM32;
2004 				break;
2005 			default:
2006 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2007 						prop);
2008 				return -EINVAL;
2009 			}
2010 		}
2011 	}
2012 
2013 	if (fifosize_prop) {
2014 		if (ourport->drv_data->fifosize[index])
2015 			ourport->port.fifosize = ourport->drv_data->fifosize[index];
2016 		else if (ourport->info->fifosize)
2017 			ourport->port.fifosize = ourport->info->fifosize;
2018 	}
2019 
2020 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2021 
2022 	/*
2023 	 * DMA transfers must be aligned at least to cache line size,
2024 	 * so find minimal transfer size suitable for DMA mode
2025 	 */
2026 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2027 				    dma_get_cache_alignment());
2028 
2029 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2030 
2031 	ret = s3c24xx_serial_init_port(ourport, pdev);
2032 	if (ret < 0)
2033 		return ret;
2034 
2035 	if (!s3c24xx_uart_drv.state) {
2036 		ret = uart_register_driver(&s3c24xx_uart_drv);
2037 		if (ret < 0) {
2038 			pr_err("Failed to register Samsung UART driver\n");
2039 			return ret;
2040 		}
2041 	}
2042 
2043 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2044 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2045 	platform_set_drvdata(pdev, &ourport->port);
2046 
2047 	/*
2048 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2049 	 * so that a potential re-enablement through the pm-callback overlaps
2050 	 * and keeps the clock enabled in this case.
2051 	 */
2052 	clk_disable_unprepare(ourport->clk);
2053 	if (!IS_ERR(ourport->baudclk))
2054 		clk_disable_unprepare(ourport->baudclk);
2055 
2056 	probe_index++;
2057 
2058 	return 0;
2059 }
2060 
2061 static void s3c24xx_serial_remove(struct platform_device *dev)
2062 {
2063 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2064 
2065 	if (port)
2066 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2067 
2068 	uart_unregister_driver(&s3c24xx_uart_drv);
2069 }
2070 
2071 /* UART power management code */
2072 #ifdef CONFIG_PM_SLEEP
2073 static int s3c24xx_serial_suspend(struct device *dev)
2074 {
2075 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2076 
2077 	if (port)
2078 		uart_suspend_port(&s3c24xx_uart_drv, port);
2079 
2080 	return 0;
2081 }
2082 
2083 static int s3c24xx_serial_resume(struct device *dev)
2084 {
2085 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2086 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2087 
2088 	if (port) {
2089 		clk_prepare_enable(ourport->clk);
2090 		if (!IS_ERR(ourport->baudclk))
2091 			clk_prepare_enable(ourport->baudclk);
2092 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2093 		if (!IS_ERR(ourport->baudclk))
2094 			clk_disable_unprepare(ourport->baudclk);
2095 		clk_disable_unprepare(ourport->clk);
2096 
2097 		uart_resume_port(&s3c24xx_uart_drv, port);
2098 	}
2099 
2100 	return 0;
2101 }
2102 
2103 static int s3c24xx_serial_resume_noirq(struct device *dev)
2104 {
2105 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2106 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2107 
2108 	if (port) {
2109 		/* restore IRQ mask */
2110 		switch (ourport->info->type) {
2111 		case TYPE_S3C6400: {
2112 			u32 uintm = 0xf;
2113 
2114 			if (ourport->tx_enabled)
2115 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2116 			if (ourport->rx_enabled)
2117 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2118 			clk_prepare_enable(ourport->clk);
2119 			if (!IS_ERR(ourport->baudclk))
2120 				clk_prepare_enable(ourport->baudclk);
2121 			wr_regl(port, S3C64XX_UINTM, uintm);
2122 			if (!IS_ERR(ourport->baudclk))
2123 				clk_disable_unprepare(ourport->baudclk);
2124 			clk_disable_unprepare(ourport->clk);
2125 			break;
2126 		}
2127 		case TYPE_APPLE_S5L: {
2128 			u32 ucon;
2129 			int ret;
2130 
2131 			ret = clk_prepare_enable(ourport->clk);
2132 			if (ret) {
2133 				dev_err(dev, "clk_enable clk failed: %d\n", ret);
2134 				return ret;
2135 			}
2136 			if (!IS_ERR(ourport->baudclk)) {
2137 				ret = clk_prepare_enable(ourport->baudclk);
2138 				if (ret) {
2139 					dev_err(dev, "clk_enable baudclk failed: %d\n", ret);
2140 					clk_disable_unprepare(ourport->clk);
2141 					return ret;
2142 				}
2143 			}
2144 
2145 			ucon = rd_regl(port, S3C2410_UCON);
2146 
2147 			ucon &= ~(APPLE_S5L_UCON_TXTHRESH_ENA_MSK |
2148 				  APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2149 				  APPLE_S5L_UCON_RXTO_ENA_MSK);
2150 
2151 			if (ourport->tx_enabled)
2152 				ucon |= APPLE_S5L_UCON_TXTHRESH_ENA_MSK;
2153 			if (ourport->rx_enabled)
2154 				ucon |= APPLE_S5L_UCON_RXTHRESH_ENA_MSK |
2155 					APPLE_S5L_UCON_RXTO_ENA_MSK;
2156 
2157 			wr_regl(port, S3C2410_UCON, ucon);
2158 
2159 			if (!IS_ERR(ourport->baudclk))
2160 				clk_disable_unprepare(ourport->baudclk);
2161 			clk_disable_unprepare(ourport->clk);
2162 			break;
2163 		}
2164 		default:
2165 			break;
2166 		}
2167 	}
2168 
2169 	return 0;
2170 }
2171 
2172 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2173 	SET_SYSTEM_SLEEP_PM_OPS(s3c24xx_serial_suspend, s3c24xx_serial_resume)
2174 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, s3c24xx_serial_resume_noirq)
2175 };
2176 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2177 
2178 #else /* !CONFIG_PM_SLEEP */
2179 
2180 #define SERIAL_SAMSUNG_PM_OPS	NULL
2181 #endif /* CONFIG_PM_SLEEP */
2182 
2183 /* Console code */
2184 
2185 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2186 
2187 static struct uart_port *cons_uart;
2188 
2189 static bool
2190 s3c24xx_serial_console_txrdy(struct uart_port *port, u32 ufcon)
2191 {
2192 	const struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2193 	u32 ufstat, utrstat;
2194 
2195 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2196 		/* fifo mode - check amount of data in fifo registers... */
2197 
2198 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2199 		return !(ufstat & info->tx_fifofull);
2200 	}
2201 
2202 	/* in non-fifo mode, we go and use the tx buffer empty */
2203 
2204 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2205 	return utrstat & S3C2410_UTRSTAT_TXE;
2206 }
2207 
2208 static bool
2209 s3c24xx_port_configured(u32 ucon)
2210 {
2211 	/* consider the serial port configured if the tx/rx mode set */
2212 	return (ucon & 0xf) != 0;
2213 }
2214 
2215 #ifdef CONFIG_CONSOLE_POLL
2216 /*
2217  * Console polling routines for writing and reading from the uart while
2218  * in an interrupt or debug context.
2219  */
2220 
2221 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2222 {
2223 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
2224 	u32 ufstat;
2225 
2226 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2227 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2228 		return NO_POLL_CHAR;
2229 
2230 	return rd_reg(port, S3C2410_URXH);
2231 }
2232 
2233 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2234 		unsigned char c)
2235 {
2236 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
2237 	u32 ucon = rd_regl(port, S3C2410_UCON);
2238 
2239 	/* not possible to xmit on unconfigured port */
2240 	if (!s3c24xx_port_configured(ucon))
2241 		return;
2242 
2243 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2244 		cpu_relax();
2245 	wr_reg(port, S3C2410_UTXH, c);
2246 }
2247 
2248 #endif /* CONFIG_CONSOLE_POLL */
2249 
2250 static void
2251 s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char ch)
2252 {
2253 	u32 ufcon = rd_regl(port, S3C2410_UFCON);
2254 
2255 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2256 		cpu_relax();
2257 	wr_reg(port, S3C2410_UTXH, ch);
2258 }
2259 
2260 static void
2261 s3c24xx_serial_console_write(struct console *co, const char *s,
2262 			     unsigned int count)
2263 {
2264 	u32 ucon = rd_regl(cons_uart, S3C2410_UCON);
2265 	unsigned long flags;
2266 	bool locked = true;
2267 
2268 	/* not possible to xmit on unconfigured port */
2269 	if (!s3c24xx_port_configured(ucon))
2270 		return;
2271 
2272 	if (cons_uart->sysrq)
2273 		locked = false;
2274 	else if (oops_in_progress)
2275 		locked = uart_port_trylock_irqsave(cons_uart, &flags);
2276 	else
2277 		uart_port_lock_irqsave(cons_uart, &flags);
2278 
2279 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2280 
2281 	if (locked)
2282 		uart_port_unlock_irqrestore(cons_uart, flags);
2283 }
2284 
2285 /* Shouldn't be __init, as it can be instantiated from other module */
2286 static void
2287 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2288 			   int *parity, int *bits)
2289 {
2290 	struct clk *clk;
2291 	unsigned long rate;
2292 	u32 ulcon, ucon, ubrdiv;
2293 	char clk_name[MAX_CLK_NAME_LENGTH];
2294 	u8 clk_sel;
2295 
2296 	ulcon  = rd_regl(port, S3C2410_ULCON);
2297 	ucon   = rd_regl(port, S3C2410_UCON);
2298 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2299 
2300 	if (s3c24xx_port_configured(ucon)) {
2301 		switch (ulcon & S3C2410_LCON_CSMASK) {
2302 		case S3C2410_LCON_CS5:
2303 			*bits = 5;
2304 			break;
2305 		case S3C2410_LCON_CS6:
2306 			*bits = 6;
2307 			break;
2308 		case S3C2410_LCON_CS7:
2309 			*bits = 7;
2310 			break;
2311 		case S3C2410_LCON_CS8:
2312 		default:
2313 			*bits = 8;
2314 			break;
2315 		}
2316 
2317 		switch (ulcon & S3C2410_LCON_PMASK) {
2318 		case S3C2410_LCON_PEVEN:
2319 			*parity = 'e';
2320 			break;
2321 
2322 		case S3C2410_LCON_PODD:
2323 			*parity = 'o';
2324 			break;
2325 
2326 		case S3C2410_LCON_PNONE:
2327 		default:
2328 			*parity = 'n';
2329 		}
2330 
2331 		/* now calculate the baud rate */
2332 
2333 		clk_sel = s3c24xx_serial_getsource(port);
2334 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2335 
2336 		clk = clk_get(port->dev, clk_name);
2337 		if (!IS_ERR(clk))
2338 			rate = clk_get_rate(clk);
2339 		else
2340 			rate = 1;
2341 
2342 		*baud = rate / (16 * (ubrdiv + 1));
2343 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2344 	}
2345 }
2346 
2347 /* Shouldn't be __init, as it can be instantiated from other module */
2348 static int
2349 s3c24xx_serial_console_setup(struct console *co, char *options)
2350 {
2351 	struct uart_port *port;
2352 	int baud = 9600;
2353 	int bits = 8;
2354 	int parity = 'n';
2355 	int flow = 'n';
2356 
2357 	/* is this a valid port */
2358 
2359 	if (co->index == -1 || co->index >= UART_NR)
2360 		co->index = 0;
2361 
2362 	port = &s3c24xx_serial_ports[co->index].port;
2363 
2364 	/* is the port configured? */
2365 
2366 	if (port->mapbase == 0x0)
2367 		return -ENODEV;
2368 
2369 	cons_uart = port;
2370 
2371 	/*
2372 	 * Check whether an invalid uart number has been specified, and
2373 	 * if so, search for the first available port that does have
2374 	 * console support.
2375 	 */
2376 	if (options)
2377 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2378 	else
2379 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2380 
2381 	dev_dbg(port->dev, "baud %d\n", baud);
2382 
2383 	return uart_set_options(port, co, baud, parity, bits, flow);
2384 }
2385 
2386 static struct console s3c24xx_serial_console = {
2387 	.name		= S3C24XX_SERIAL_NAME,
2388 	.device		= uart_console_device,
2389 	.flags		= CON_PRINTBUFFER,
2390 	.index		= -1,
2391 	.write		= s3c24xx_serial_console_write,
2392 	.setup		= s3c24xx_serial_console_setup,
2393 	.data		= &s3c24xx_uart_drv,
2394 };
2395 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2396 
2397 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2398 static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2399 	.info = {
2400 		.name		= "Samsung S3C6400 UART",
2401 		.type		= TYPE_S3C6400,
2402 		.port_type	= PORT_S3C6400,
2403 		.iotype		= UPIO_MEM,
2404 		.fifosize	= 64,
2405 		.has_divslot	= true,
2406 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2407 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2408 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2409 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2410 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2411 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2412 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2413 		.num_clks	= 4,
2414 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2415 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2416 	},
2417 	.def_cfg = {
2418 		.ucon		= S3C2410_UCON_DEFAULT,
2419 		.ufcon		= S3C2410_UFCON_DEFAULT,
2420 	},
2421 };
2422 #define S3C6400_SERIAL_DRV_DATA (&s3c6400_serial_drv_data)
2423 #else
2424 #define S3C6400_SERIAL_DRV_DATA NULL
2425 #endif
2426 
2427 #ifdef CONFIG_CPU_S5PV210
2428 static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2429 	.info = {
2430 		.name		= "Samsung S5PV210 UART",
2431 		.type		= TYPE_S3C6400,
2432 		.port_type	= PORT_S3C6400,
2433 		.iotype		= UPIO_MEM,
2434 		.has_divslot	= true,
2435 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2436 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2437 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2438 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2439 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2440 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2441 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2442 		.num_clks	= 2,
2443 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2444 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2445 	},
2446 	.def_cfg = {
2447 		.ucon		= S5PV210_UCON_DEFAULT,
2448 		.ufcon		= S5PV210_UFCON_DEFAULT,
2449 	},
2450 	.fifosize = { 256, 64, 16, 16 },
2451 };
2452 #define S5PV210_SERIAL_DRV_DATA (&s5pv210_serial_drv_data)
2453 #else
2454 #define S5PV210_SERIAL_DRV_DATA	NULL
2455 #endif
2456 
2457 #if defined(CONFIG_ARCH_EXYNOS)
2458 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2459 	.info = {						\
2460 		.name		= "Samsung Exynos UART",	\
2461 		.type		= TYPE_S3C6400,			\
2462 		.port_type	= PORT_S3C6400,			\
2463 		.iotype		= UPIO_MEM,			\
2464 		.has_divslot	= true,				\
2465 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2466 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2467 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2468 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2469 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2470 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2471 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2472 		.num_clks	= 1,				\
2473 		.clksel_mask	= 0,				\
2474 		.clksel_shift	= 0,				\
2475 	},							\
2476 	.def_cfg = {						\
2477 		.ucon		= S5PV210_UCON_DEFAULT,		\
2478 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2479 		.has_fracval	= 1,				\
2480 	}							\
2481 
2482 static const struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2483 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2484 	.fifosize = { 256, 64, 16, 16 },
2485 };
2486 
2487 static const struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2488 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2489 	.fifosize = { 64, 256, 16, 256 },
2490 };
2491 
2492 static const struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
2493 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2494 	.fifosize = { 256, 64, 64, 64 },
2495 };
2496 
2497 static const struct s3c24xx_serial_drv_data gs101_serial_drv_data = {
2498 	.info = {
2499 		.name		= "Google GS101 UART",
2500 		.type		= TYPE_S3C6400,
2501 		.port_type	= PORT_S3C6400,
2502 		.iotype		= UPIO_MEM32,
2503 		.has_divslot	= true,
2504 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2505 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2506 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2507 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2508 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2509 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2510 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2511 		.num_clks	= 1,
2512 		.clksel_mask	= 0,
2513 		.clksel_shift	= 0,
2514 	},
2515 	.def_cfg = {
2516 		.ucon		= S5PV210_UCON_DEFAULT,
2517 		.ufcon		= S5PV210_UFCON_DEFAULT,
2518 		.has_fracval	= 1,
2519 	},
2520 	/* samsung,uart-fifosize must be specified in the device tree. */
2521 	.fifosize = { 0 },
2522 };
2523 
2524 #define EXYNOS4210_SERIAL_DRV_DATA (&exynos4210_serial_drv_data)
2525 #define EXYNOS5433_SERIAL_DRV_DATA (&exynos5433_serial_drv_data)
2526 #define EXYNOS850_SERIAL_DRV_DATA (&exynos850_serial_drv_data)
2527 #define GS101_SERIAL_DRV_DATA (&gs101_serial_drv_data)
2528 
2529 #else
2530 #define EXYNOS4210_SERIAL_DRV_DATA NULL
2531 #define EXYNOS5433_SERIAL_DRV_DATA NULL
2532 #define EXYNOS850_SERIAL_DRV_DATA NULL
2533 #define GS101_SERIAL_DRV_DATA NULL
2534 #endif
2535 
2536 #ifdef CONFIG_ARCH_APPLE
2537 static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
2538 	.info = {
2539 		.name		= "Apple S5L UART",
2540 		.type		= TYPE_APPLE_S5L,
2541 		.port_type	= PORT_8250,
2542 		.iotype		= UPIO_MEM,
2543 		.fifosize	= 16,
2544 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2545 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2546 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2547 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2548 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2549 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2550 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2551 		.num_clks	= 1,
2552 		.clksel_mask	= 0,
2553 		.clksel_shift	= 0,
2554 		.ucon_mask	= APPLE_S5L_UCON_MASK,
2555 	},
2556 	.def_cfg = {
2557 		.ucon		= APPLE_S5L_UCON_DEFAULT,
2558 		.ufcon		= S3C2410_UFCON_DEFAULT,
2559 	},
2560 };
2561 #define S5L_SERIAL_DRV_DATA (&s5l_serial_drv_data)
2562 #else
2563 #define S5L_SERIAL_DRV_DATA NULL
2564 #endif
2565 
2566 #if defined(CONFIG_ARCH_ARTPEC)
2567 static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
2568 	.info = {
2569 		.name		= "Axis ARTPEC-8 UART",
2570 		.type		= TYPE_S3C6400,
2571 		.port_type	= PORT_S3C6400,
2572 		.iotype		= UPIO_MEM,
2573 		.fifosize	= 64,
2574 		.has_divslot	= true,
2575 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2576 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2577 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2578 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2579 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2580 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2581 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2582 		.num_clks	= 1,
2583 		.clksel_mask	= 0,
2584 		.clksel_shift	= 0,
2585 	},
2586 	.def_cfg = {
2587 		.ucon		= S5PV210_UCON_DEFAULT,
2588 		.ufcon		= S5PV210_UFCON_DEFAULT,
2589 		.has_fracval	= 1,
2590 	}
2591 };
2592 #define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
2593 #else
2594 #define ARTPEC8_SERIAL_DRV_DATA (NULL)
2595 #endif
2596 
2597 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2598 	{
2599 		.name		= "s3c6400-uart",
2600 		.driver_data	= (kernel_ulong_t)S3C6400_SERIAL_DRV_DATA,
2601 	}, {
2602 		.name		= "s5pv210-uart",
2603 		.driver_data	= (kernel_ulong_t)S5PV210_SERIAL_DRV_DATA,
2604 	}, {
2605 		.name		= "exynos4210-uart",
2606 		.driver_data	= (kernel_ulong_t)EXYNOS4210_SERIAL_DRV_DATA,
2607 	}, {
2608 		.name		= "exynos5433-uart",
2609 		.driver_data	= (kernel_ulong_t)EXYNOS5433_SERIAL_DRV_DATA,
2610 	}, {
2611 		.name		= "s5l-uart",
2612 		.driver_data	= (kernel_ulong_t)S5L_SERIAL_DRV_DATA,
2613 	}, {
2614 		.name		= "exynos850-uart",
2615 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
2616 	}, {
2617 		.name		= "artpec8-uart",
2618 		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
2619 	}, {
2620 		.name		= "gs101-uart",
2621 		.driver_data	= (kernel_ulong_t)GS101_SERIAL_DRV_DATA,
2622 	},
2623 	{ },
2624 };
2625 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2626 
2627 #ifdef CONFIG_OF
2628 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2629 	{ .compatible = "samsung,s3c6400-uart",
2630 		.data = S3C6400_SERIAL_DRV_DATA },
2631 	{ .compatible = "samsung,s5pv210-uart",
2632 		.data = S5PV210_SERIAL_DRV_DATA },
2633 	{ .compatible = "samsung,exynos4210-uart",
2634 		.data = EXYNOS4210_SERIAL_DRV_DATA },
2635 	{ .compatible = "samsung,exynos5433-uart",
2636 		.data = EXYNOS5433_SERIAL_DRV_DATA },
2637 	{ .compatible = "apple,s5l-uart",
2638 		.data = S5L_SERIAL_DRV_DATA },
2639 	{ .compatible = "samsung,exynos850-uart",
2640 		.data = EXYNOS850_SERIAL_DRV_DATA },
2641 	{ .compatible = "axis,artpec8-uart",
2642 		.data = ARTPEC8_SERIAL_DRV_DATA },
2643 	{ .compatible = "google,gs101-uart",
2644 		.data = GS101_SERIAL_DRV_DATA },
2645 	{},
2646 };
2647 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2648 #endif
2649 
2650 static struct platform_driver samsung_serial_driver = {
2651 	.probe		= s3c24xx_serial_probe,
2652 	.remove_new	= s3c24xx_serial_remove,
2653 	.id_table	= s3c24xx_serial_driver_ids,
2654 	.driver		= {
2655 		.name	= "samsung-uart",
2656 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2657 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2658 	},
2659 };
2660 
2661 static int __init samsung_serial_init(void)
2662 {
2663 	int ret;
2664 
2665 	s3c24xx_serial_register_console();
2666 
2667 	ret = platform_driver_register(&samsung_serial_driver);
2668 	if (ret) {
2669 		s3c24xx_serial_unregister_console();
2670 		return ret;
2671 	}
2672 
2673 	return 0;
2674 }
2675 
2676 static void __exit samsung_serial_exit(void)
2677 {
2678 	platform_driver_unregister(&samsung_serial_driver);
2679 	s3c24xx_serial_unregister_console();
2680 }
2681 
2682 module_init(samsung_serial_init);
2683 module_exit(samsung_serial_exit);
2684 
2685 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2686 /*
2687  * Early console.
2688  */
2689 
2690 static void wr_reg_barrier(const struct uart_port *port, u32 reg, u32 val)
2691 {
2692 	switch (port->iotype) {
2693 	case UPIO_MEM:
2694 		writeb(val, portaddr(port, reg));
2695 		break;
2696 	case UPIO_MEM32:
2697 		writel(val, portaddr(port, reg));
2698 		break;
2699 	}
2700 }
2701 
2702 struct samsung_early_console_data {
2703 	u32 txfull_mask;
2704 	u32 rxfifo_mask;
2705 };
2706 
2707 static void samsung_early_busyuart(const struct uart_port *port)
2708 {
2709 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2710 		;
2711 }
2712 
2713 static void samsung_early_busyuart_fifo(const struct uart_port *port)
2714 {
2715 	const struct samsung_early_console_data *data = port->private_data;
2716 
2717 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2718 		;
2719 }
2720 
2721 static void samsung_early_putc(struct uart_port *port, unsigned char c)
2722 {
2723 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2724 		samsung_early_busyuart_fifo(port);
2725 	else
2726 		samsung_early_busyuart(port);
2727 
2728 	wr_reg_barrier(port, S3C2410_UTXH, c);
2729 }
2730 
2731 static void samsung_early_write(struct console *con, const char *s,
2732 				unsigned int n)
2733 {
2734 	struct earlycon_device *dev = con->data;
2735 
2736 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2737 }
2738 
2739 static int samsung_early_read(struct console *con, char *s, unsigned int n)
2740 {
2741 	struct earlycon_device *dev = con->data;
2742 	const struct samsung_early_console_data *data = dev->port.private_data;
2743 	int num_read = 0;
2744 	u32 ch, ufstat;
2745 
2746 	while (num_read < n) {
2747 		ufstat = rd_regl(&dev->port, S3C2410_UFSTAT);
2748 		if (!(ufstat & data->rxfifo_mask))
2749 			break;
2750 		ch = rd_reg(&dev->port, S3C2410_URXH);
2751 		if (ch == NO_POLL_CHAR)
2752 			break;
2753 
2754 		s[num_read++] = ch;
2755 	}
2756 
2757 	return num_read;
2758 }
2759 
2760 static int __init samsung_early_console_setup(struct earlycon_device *device,
2761 					      const char *opt)
2762 {
2763 	if (!device->port.membase)
2764 		return -ENODEV;
2765 
2766 	device->con->write = samsung_early_write;
2767 	device->con->read = samsung_early_read;
2768 	return 0;
2769 }
2770 
2771 /* S3C2410 */
2772 static struct samsung_early_console_data s3c2410_early_console_data = {
2773 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2774 	.rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK,
2775 };
2776 
2777 /* S3C64xx */
2778 static struct samsung_early_console_data s3c2440_early_console_data = {
2779 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2780 	.rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK,
2781 };
2782 
2783 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2784 					      const char *opt)
2785 {
2786 	device->port.private_data = &s3c2440_early_console_data;
2787 	return samsung_early_console_setup(device, opt);
2788 }
2789 
2790 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2791 			s3c2440_early_console_setup);
2792 
2793 /* S5PV210, Exynos */
2794 static struct samsung_early_console_data s5pv210_early_console_data = {
2795 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2796 	.rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK,
2797 };
2798 
2799 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2800 					      const char *opt)
2801 {
2802 	device->port.private_data = &s5pv210_early_console_data;
2803 	return samsung_early_console_setup(device, opt);
2804 }
2805 
2806 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2807 			s5pv210_early_console_setup);
2808 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2809 			s5pv210_early_console_setup);
2810 OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
2811 			s5pv210_early_console_setup);
2812 
2813 static int __init gs101_early_console_setup(struct earlycon_device *device,
2814 					    const char *opt)
2815 {
2816 	/* gs101 always expects MMIO32 register accesses. */
2817 	device->port.iotype = UPIO_MEM32;
2818 
2819 	return s5pv210_early_console_setup(device, opt);
2820 }
2821 
2822 OF_EARLYCON_DECLARE(gs101, "google,gs101-uart", gs101_early_console_setup);
2823 
2824 /* Apple S5L */
2825 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
2826 						const char *opt)
2827 {
2828 	/* Close enough to S3C2410 for earlycon... */
2829 	device->port.private_data = &s3c2410_early_console_data;
2830 
2831 #ifdef CONFIG_ARM64
2832 	/* ... but we need to override the existing fixmap entry as nGnRnE */
2833 	__set_fixmap(FIX_EARLYCON_MEM_BASE, device->port.mapbase,
2834 		     __pgprot(PROT_DEVICE_nGnRnE));
2835 #endif
2836 	return samsung_early_console_setup(device, opt);
2837 }
2838 
2839 OF_EARLYCON_DECLARE(s5l, "apple,s5l-uart", apple_s5l_early_console_setup);
2840 #endif
2841 
2842 MODULE_ALIAS("platform:samsung-uart");
2843 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2844 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2845 MODULE_LICENSE("GPL v2");
2846