xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision cee50c2a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Hote on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/ioport.h>
29 #include <linux/io.h>
30 #include <linux/platform_device.h>
31 #include <linux/init.h>
32 #include <linux/sysrq.h>
33 #include <linux/console.h>
34 #include <linux/tty.h>
35 #include <linux/tty_flip.h>
36 #include <linux/serial_core.h>
37 #include <linux/serial.h>
38 #include <linux/serial_s3c.h>
39 #include <linux/delay.h>
40 #include <linux/clk.h>
41 #include <linux/cpufreq.h>
42 #include <linux/of.h>
43 #include <asm/irq.h>
44 
45 /* UART name and device definitions */
46 
47 #define S3C24XX_SERIAL_NAME	"ttySAC"
48 #define S3C24XX_SERIAL_MAJOR	204
49 #define S3C24XX_SERIAL_MINOR	64
50 
51 #define S3C24XX_TX_PIO			1
52 #define S3C24XX_TX_DMA			2
53 #define S3C24XX_RX_PIO			1
54 #define S3C24XX_RX_DMA			2
55 
56 /* flag to ignore all characters coming in */
57 #define RXSTAT_DUMMY_READ (0x10000000)
58 
59 struct s3c24xx_uart_info {
60 	char			*name;
61 	unsigned int		type;
62 	unsigned int		fifosize;
63 	unsigned long		rx_fifomask;
64 	unsigned long		rx_fifoshift;
65 	unsigned long		rx_fifofull;
66 	unsigned long		tx_fifomask;
67 	unsigned long		tx_fifoshift;
68 	unsigned long		tx_fifofull;
69 	unsigned int		def_clk_sel;
70 	unsigned long		num_clks;
71 	unsigned long		clksel_mask;
72 	unsigned long		clksel_shift;
73 
74 	/* uart port features */
75 
76 	unsigned int		has_divslot:1;
77 };
78 
79 struct s3c24xx_serial_drv_data {
80 	struct s3c24xx_uart_info	*info;
81 	struct s3c2410_uartcfg		*def_cfg;
82 	unsigned int			fifosize[CONFIG_SERIAL_SAMSUNG_UARTS];
83 };
84 
85 struct s3c24xx_uart_dma {
86 	unsigned int			rx_chan_id;
87 	unsigned int			tx_chan_id;
88 
89 	struct dma_slave_config		rx_conf;
90 	struct dma_slave_config		tx_conf;
91 
92 	struct dma_chan			*rx_chan;
93 	struct dma_chan			*tx_chan;
94 
95 	dma_addr_t			rx_addr;
96 	dma_addr_t			tx_addr;
97 
98 	dma_cookie_t			rx_cookie;
99 	dma_cookie_t			tx_cookie;
100 
101 	char				*rx_buf;
102 
103 	dma_addr_t			tx_transfer_addr;
104 
105 	size_t				rx_size;
106 	size_t				tx_size;
107 
108 	struct dma_async_tx_descriptor	*tx_desc;
109 	struct dma_async_tx_descriptor	*rx_desc;
110 
111 	int				tx_bytes_requested;
112 	int				rx_bytes_requested;
113 };
114 
115 struct s3c24xx_uart_port {
116 	unsigned char			rx_claimed;
117 	unsigned char			tx_claimed;
118 	unsigned char			rx_enabled;
119 	unsigned char			tx_enabled;
120 	unsigned int			pm_level;
121 	unsigned long			baudclk_rate;
122 	unsigned int			min_dma_size;
123 
124 	unsigned int			rx_irq;
125 	unsigned int			tx_irq;
126 
127 	unsigned int			tx_in_progress;
128 	unsigned int			tx_mode;
129 	unsigned int			rx_mode;
130 
131 	struct s3c24xx_uart_info	*info;
132 	struct clk			*clk;
133 	struct clk			*baudclk;
134 	struct uart_port		port;
135 	struct s3c24xx_serial_drv_data	*drv_data;
136 
137 	/* reference to platform data */
138 	struct s3c2410_uartcfg		*cfg;
139 
140 	struct s3c24xx_uart_dma		*dma;
141 
142 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
143 	struct notifier_block		freq_transition;
144 #endif
145 };
146 
147 /* conversion functions */
148 
149 #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev)
150 
151 /* register access controls */
152 
153 #define portaddr(port, reg) ((port)->membase + (reg))
154 #define portaddrl(port, reg) \
155 	((unsigned long *)(unsigned long)((port)->membase + (reg)))
156 
157 static u32 rd_reg(struct uart_port *port, u32 reg)
158 {
159 	switch (port->iotype) {
160 	case UPIO_MEM:
161 		return readb_relaxed(portaddr(port, reg));
162 	case UPIO_MEM32:
163 		return readl_relaxed(portaddr(port, reg));
164 	default:
165 		return 0;
166 	}
167 	return 0;
168 }
169 
170 #define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))
171 
172 static void wr_reg(struct uart_port *port, u32 reg, u32 val)
173 {
174 	switch (port->iotype) {
175 	case UPIO_MEM:
176 		writeb_relaxed(val, portaddr(port, reg));
177 		break;
178 	case UPIO_MEM32:
179 		writel_relaxed(val, portaddr(port, reg));
180 		break;
181 	}
182 }
183 
184 #define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))
185 
186 /* Byte-order aware bit setting/clearing functions. */
187 
188 static inline void s3c24xx_set_bit(struct uart_port *port, int idx,
189 				   unsigned int reg)
190 {
191 	unsigned long flags;
192 	u32 val;
193 
194 	local_irq_save(flags);
195 	val = rd_regl(port, reg);
196 	val |= (1 << idx);
197 	wr_regl(port, reg, val);
198 	local_irq_restore(flags);
199 }
200 
201 static inline void s3c24xx_clear_bit(struct uart_port *port, int idx,
202 				     unsigned int reg)
203 {
204 	unsigned long flags;
205 	u32 val;
206 
207 	local_irq_save(flags);
208 	val = rd_regl(port, reg);
209 	val &= ~(1 << idx);
210 	wr_regl(port, reg, val);
211 	local_irq_restore(flags);
212 }
213 
214 static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
215 {
216 	return container_of(port, struct s3c24xx_uart_port, port);
217 }
218 
219 /* translate a port to the device name */
220 
221 static inline const char *s3c24xx_serial_portname(struct uart_port *port)
222 {
223 	return to_platform_device(port->dev)->name;
224 }
225 
226 static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
227 {
228 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
229 }
230 
231 /*
232  * s3c64xx and later SoC's include the interrupt mask and status registers in
233  * the controller itself, unlike the s3c24xx SoC's which have these registers
234  * in the interrupt controller. Check if the port type is s3c64xx or higher.
235  */
236 static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
237 {
238 	return to_ourport(port)->info->type == PORT_S3C6400;
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 	spin_lock_irqsave(&port->lock, 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 	spin_unlock_irqrestore(&port->lock, 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 	spin_lock_irqsave(&port->lock, 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 	spin_unlock_irqrestore(&port->lock, 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 circ_buf *xmit = &port->state->xmit;
286 	struct dma_tx_state state;
287 	int count;
288 
289 	if (!ourport->tx_enabled)
290 		return;
291 
292 	if (s3c24xx_serial_has_interrupt_mask(port))
293 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
294 	else
295 		disable_irq_nosync(ourport->tx_irq);
296 
297 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
298 		dmaengine_pause(dma->tx_chan);
299 		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
300 		dmaengine_terminate_all(dma->tx_chan);
301 		dma_sync_single_for_cpu(ourport->port.dev,
302 			dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE);
303 		async_tx_ack(dma->tx_desc);
304 		count = dma->tx_bytes_requested - state.residue;
305 		xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
306 		port->icount.tx += count;
307 	}
308 
309 	ourport->tx_enabled = 0;
310 	ourport->tx_in_progress = 0;
311 
312 	if (port->flags & UPF_CONS_FLOW)
313 		s3c24xx_serial_rx_enable(port);
314 
315 	ourport->tx_mode = 0;
316 }
317 
318 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
319 
320 static void s3c24xx_serial_tx_dma_complete(void *args)
321 {
322 	struct s3c24xx_uart_port *ourport = args;
323 	struct uart_port *port = &ourport->port;
324 	struct circ_buf *xmit = &port->state->xmit;
325 	struct s3c24xx_uart_dma *dma = ourport->dma;
326 	struct dma_tx_state state;
327 	unsigned long flags;
328 	int count;
329 
330 
331 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
332 	count = dma->tx_bytes_requested - state.residue;
333 	async_tx_ack(dma->tx_desc);
334 
335 	dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr,
336 				dma->tx_size, DMA_TO_DEVICE);
337 
338 	spin_lock_irqsave(&port->lock, flags);
339 
340 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
341 	port->icount.tx += count;
342 	ourport->tx_in_progress = 0;
343 
344 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
345 		uart_write_wakeup(port);
346 
347 	s3c24xx_serial_start_next_tx(ourport);
348 	spin_unlock_irqrestore(&port->lock, flags);
349 }
350 
351 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
352 {
353 	struct uart_port *port = &ourport->port;
354 	u32 ucon;
355 
356 	/* Mask Tx interrupt */
357 	if (s3c24xx_serial_has_interrupt_mask(port))
358 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
359 	else
360 		disable_irq_nosync(ourport->tx_irq);
361 
362 	/* Enable tx dma mode */
363 	ucon = rd_regl(port, S3C2410_UCON);
364 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
365 	ucon |= (dma_get_cache_alignment() >= 16) ?
366 		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
367 	ucon |= S3C64XX_UCON_TXMODE_DMA;
368 	wr_regl(port,  S3C2410_UCON, ucon);
369 
370 	ourport->tx_mode = S3C24XX_TX_DMA;
371 }
372 
373 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
374 {
375 	struct uart_port *port = &ourport->port;
376 	u32 ucon, ufcon;
377 
378 	/* Set ufcon txtrig */
379 	ourport->tx_in_progress = S3C24XX_TX_PIO;
380 	ufcon = rd_regl(port, S3C2410_UFCON);
381 	wr_regl(port,  S3C2410_UFCON, ufcon);
382 
383 	/* Enable tx pio mode */
384 	ucon = rd_regl(port, S3C2410_UCON);
385 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
386 	ucon |= S3C64XX_UCON_TXMODE_CPU;
387 	wr_regl(port,  S3C2410_UCON, ucon);
388 
389 	/* Unmask Tx interrupt */
390 	if (s3c24xx_serial_has_interrupt_mask(port))
391 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
392 				  S3C64XX_UINTM);
393 	else
394 		enable_irq(ourport->tx_irq);
395 
396 	ourport->tx_mode = S3C24XX_TX_PIO;
397 }
398 
399 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
400 {
401 	if (ourport->tx_mode != S3C24XX_TX_PIO)
402 		enable_tx_pio(ourport);
403 }
404 
405 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
406 				      unsigned int count)
407 {
408 	struct uart_port *port = &ourport->port;
409 	struct circ_buf *xmit = &port->state->xmit;
410 	struct s3c24xx_uart_dma *dma = ourport->dma;
411 
412 
413 	if (ourport->tx_mode != S3C24XX_TX_DMA)
414 		enable_tx_dma(ourport);
415 
416 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
417 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
418 
419 	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
420 				dma->tx_size, DMA_TO_DEVICE);
421 
422 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
423 				dma->tx_transfer_addr, dma->tx_size,
424 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
425 	if (!dma->tx_desc) {
426 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
427 		return -EIO;
428 	}
429 
430 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
431 	dma->tx_desc->callback_param = ourport;
432 	dma->tx_bytes_requested = dma->tx_size;
433 
434 	ourport->tx_in_progress = S3C24XX_TX_DMA;
435 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
436 	dma_async_issue_pending(dma->tx_chan);
437 	return 0;
438 }
439 
440 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
441 {
442 	struct uart_port *port = &ourport->port;
443 	struct circ_buf *xmit = &port->state->xmit;
444 	unsigned long count;
445 
446 	/* Get data size up to the end of buffer */
447 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
448 
449 	if (!count) {
450 		s3c24xx_serial_stop_tx(port);
451 		return;
452 	}
453 
454 	if (!ourport->dma || !ourport->dma->tx_chan ||
455 	    count < ourport->min_dma_size ||
456 	    xmit->tail & (dma_get_cache_alignment() - 1))
457 		s3c24xx_serial_start_tx_pio(ourport);
458 	else
459 		s3c24xx_serial_start_tx_dma(ourport, count);
460 }
461 
462 static void s3c24xx_serial_start_tx(struct uart_port *port)
463 {
464 	struct s3c24xx_uart_port *ourport = to_ourport(port);
465 	struct circ_buf *xmit = &port->state->xmit;
466 
467 	if (!ourport->tx_enabled) {
468 		if (port->flags & UPF_CONS_FLOW)
469 			s3c24xx_serial_rx_disable(port);
470 
471 		ourport->tx_enabled = 1;
472 		if (!ourport->dma || !ourport->dma->tx_chan)
473 			s3c24xx_serial_start_tx_pio(ourport);
474 	}
475 
476 	if (ourport->dma && ourport->dma->tx_chan) {
477 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
478 			s3c24xx_serial_start_next_tx(ourport);
479 	}
480 }
481 
482 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
483 		struct tty_port *tty, int count)
484 {
485 	struct s3c24xx_uart_dma *dma = ourport->dma;
486 	int copied;
487 
488 	if (!count)
489 		return;
490 
491 	dma_sync_single_for_cpu(ourport->port.dev, dma->rx_addr,
492 				dma->rx_size, DMA_FROM_DEVICE);
493 
494 	ourport->port.icount.rx += count;
495 	if (!tty) {
496 		dev_err(ourport->port.dev, "No tty port\n");
497 		return;
498 	}
499 	copied = tty_insert_flip_string(tty,
500 			((unsigned char *)(ourport->dma->rx_buf)), count);
501 	if (copied != count) {
502 		WARN_ON(1);
503 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
504 	}
505 }
506 
507 static void s3c24xx_serial_stop_rx(struct uart_port *port)
508 {
509 	struct s3c24xx_uart_port *ourport = to_ourport(port);
510 	struct s3c24xx_uart_dma *dma = ourport->dma;
511 	struct tty_port *t = &port->state->port;
512 	struct dma_tx_state state;
513 	enum dma_status dma_status;
514 	unsigned int received;
515 
516 	if (ourport->rx_enabled) {
517 		dev_dbg(port->dev, "stopping rx\n");
518 		if (s3c24xx_serial_has_interrupt_mask(port))
519 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
520 					S3C64XX_UINTM);
521 		else
522 			disable_irq_nosync(ourport->rx_irq);
523 		ourport->rx_enabled = 0;
524 	}
525 	if (dma && dma->rx_chan) {
526 		dmaengine_pause(dma->tx_chan);
527 		dma_status = dmaengine_tx_status(dma->rx_chan,
528 				dma->rx_cookie, &state);
529 		if (dma_status == DMA_IN_PROGRESS ||
530 			dma_status == DMA_PAUSED) {
531 			received = dma->rx_bytes_requested - state.residue;
532 			dmaengine_terminate_all(dma->rx_chan);
533 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
534 		}
535 	}
536 }
537 
538 static inline struct s3c24xx_uart_info
539 	*s3c24xx_port_to_info(struct uart_port *port)
540 {
541 	return to_ourport(port)->info;
542 }
543 
544 static inline struct s3c2410_uartcfg
545 	*s3c24xx_port_to_cfg(struct uart_port *port)
546 {
547 	struct s3c24xx_uart_port *ourport;
548 
549 	if (port->dev == NULL)
550 		return NULL;
551 
552 	ourport = container_of(port, struct s3c24xx_uart_port, port);
553 	return ourport->cfg;
554 }
555 
556 static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
557 				     unsigned long ufstat)
558 {
559 	struct s3c24xx_uart_info *info = ourport->info;
560 
561 	if (ufstat & info->rx_fifofull)
562 		return ourport->port.fifosize;
563 
564 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
565 }
566 
567 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
568 static void s3c24xx_serial_rx_dma_complete(void *args)
569 {
570 	struct s3c24xx_uart_port *ourport = args;
571 	struct uart_port *port = &ourport->port;
572 
573 	struct s3c24xx_uart_dma *dma = ourport->dma;
574 	struct tty_port *t = &port->state->port;
575 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
576 
577 	struct dma_tx_state state;
578 	unsigned long flags;
579 	int received;
580 
581 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
582 	received  = dma->rx_bytes_requested - state.residue;
583 	async_tx_ack(dma->rx_desc);
584 
585 	spin_lock_irqsave(&port->lock, flags);
586 
587 	if (received)
588 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
589 
590 	if (tty) {
591 		tty_flip_buffer_push(t);
592 		tty_kref_put(tty);
593 	}
594 
595 	s3c64xx_start_rx_dma(ourport);
596 
597 	spin_unlock_irqrestore(&port->lock, flags);
598 }
599 
600 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
601 {
602 	struct s3c24xx_uart_dma *dma = ourport->dma;
603 
604 	dma_sync_single_for_device(ourport->port.dev, dma->rx_addr,
605 				dma->rx_size, DMA_FROM_DEVICE);
606 
607 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
608 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
609 				DMA_PREP_INTERRUPT);
610 	if (!dma->rx_desc) {
611 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
612 		return;
613 	}
614 
615 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
616 	dma->rx_desc->callback_param = ourport;
617 	dma->rx_bytes_requested = dma->rx_size;
618 
619 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
620 	dma_async_issue_pending(dma->rx_chan);
621 }
622 
623 /* ? - where has parity gone?? */
624 #define S3C2410_UERSTAT_PARITY (0x1000)
625 
626 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
627 {
628 	struct uart_port *port = &ourport->port;
629 	unsigned int ucon;
630 
631 	/* set Rx mode to DMA mode */
632 	ucon = rd_regl(port, S3C2410_UCON);
633 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
634 			S3C64XX_UCON_TIMEOUT_MASK |
635 			S3C64XX_UCON_EMPTYINT_EN |
636 			S3C64XX_UCON_DMASUS_EN |
637 			S3C64XX_UCON_TIMEOUT_EN |
638 			S3C64XX_UCON_RXMODE_MASK);
639 	ucon |= S3C64XX_UCON_RXBURST_16 |
640 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
641 			S3C64XX_UCON_EMPTYINT_EN |
642 			S3C64XX_UCON_TIMEOUT_EN |
643 			S3C64XX_UCON_RXMODE_DMA;
644 	wr_regl(port, S3C2410_UCON, ucon);
645 
646 	ourport->rx_mode = S3C24XX_RX_DMA;
647 }
648 
649 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
650 {
651 	struct uart_port *port = &ourport->port;
652 	unsigned int ucon;
653 
654 	/* set Rx mode to DMA mode */
655 	ucon = rd_regl(port, S3C2410_UCON);
656 	ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
657 			S3C64XX_UCON_EMPTYINT_EN |
658 			S3C64XX_UCON_DMASUS_EN |
659 			S3C64XX_UCON_TIMEOUT_EN |
660 			S3C64XX_UCON_RXMODE_MASK);
661 	ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
662 			S3C64XX_UCON_TIMEOUT_EN |
663 			S3C64XX_UCON_RXMODE_CPU;
664 	wr_regl(port, S3C2410_UCON, ucon);
665 
666 	ourport->rx_mode = S3C24XX_RX_PIO;
667 }
668 
669 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
670 
671 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
672 {
673 	unsigned int utrstat, received;
674 	struct s3c24xx_uart_port *ourport = dev_id;
675 	struct uart_port *port = &ourport->port;
676 	struct s3c24xx_uart_dma *dma = ourport->dma;
677 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
678 	struct tty_port *t = &port->state->port;
679 	unsigned long flags;
680 	struct dma_tx_state state;
681 
682 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
683 	rd_regl(port, S3C2410_UFSTAT);
684 
685 	spin_lock_irqsave(&port->lock, flags);
686 
687 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
688 		s3c64xx_start_rx_dma(ourport);
689 		if (ourport->rx_mode == S3C24XX_RX_PIO)
690 			enable_rx_dma(ourport);
691 		goto finish;
692 	}
693 
694 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
695 		dmaengine_pause(dma->rx_chan);
696 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
697 		dmaengine_terminate_all(dma->rx_chan);
698 		received = dma->rx_bytes_requested - state.residue;
699 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
700 
701 		enable_rx_pio(ourport);
702 	}
703 
704 	s3c24xx_serial_rx_drain_fifo(ourport);
705 
706 	if (tty) {
707 		tty_flip_buffer_push(t);
708 		tty_kref_put(tty);
709 	}
710 
711 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
712 
713 finish:
714 	spin_unlock_irqrestore(&port->lock, flags);
715 
716 	return IRQ_HANDLED;
717 }
718 
719 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
720 {
721 	struct uart_port *port = &ourport->port;
722 	unsigned int ufcon, ch, flag, ufstat, uerstat;
723 	unsigned int fifocnt = 0;
724 	int max_count = port->fifosize;
725 
726 	while (max_count-- > 0) {
727 		/*
728 		 * Receive all characters known to be in FIFO
729 		 * before reading FIFO level again
730 		 */
731 		if (fifocnt == 0) {
732 			ufstat = rd_regl(port, S3C2410_UFSTAT);
733 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
734 			if (fifocnt == 0)
735 				break;
736 		}
737 		fifocnt--;
738 
739 		uerstat = rd_regl(port, S3C2410_UERSTAT);
740 		ch = rd_reg(port, S3C2410_URXH);
741 
742 		if (port->flags & UPF_CONS_FLOW) {
743 			int txe = s3c24xx_serial_txempty_nofifo(port);
744 
745 			if (ourport->rx_enabled) {
746 				if (!txe) {
747 					ourport->rx_enabled = 0;
748 					continue;
749 				}
750 			} else {
751 				if (txe) {
752 					ufcon = rd_regl(port, S3C2410_UFCON);
753 					ufcon |= S3C2410_UFCON_RESETRX;
754 					wr_regl(port, S3C2410_UFCON, ufcon);
755 					ourport->rx_enabled = 1;
756 					return;
757 				}
758 				continue;
759 			}
760 		}
761 
762 		/* insert the character into the buffer */
763 
764 		flag = TTY_NORMAL;
765 		port->icount.rx++;
766 
767 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
768 			dev_dbg(port->dev,
769 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
770 				ch, uerstat);
771 
772 			/* check for break */
773 			if (uerstat & S3C2410_UERSTAT_BREAK) {
774 				dev_dbg(port->dev, "break!\n");
775 				port->icount.brk++;
776 				if (uart_handle_break(port))
777 					continue; /* Ignore character */
778 			}
779 
780 			if (uerstat & S3C2410_UERSTAT_FRAME)
781 				port->icount.frame++;
782 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
783 				port->icount.overrun++;
784 
785 			uerstat &= port->read_status_mask;
786 
787 			if (uerstat & S3C2410_UERSTAT_BREAK)
788 				flag = TTY_BREAK;
789 			else if (uerstat & S3C2410_UERSTAT_PARITY)
790 				flag = TTY_PARITY;
791 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
792 					    S3C2410_UERSTAT_OVERRUN))
793 				flag = TTY_FRAME;
794 		}
795 
796 		if (uart_handle_sysrq_char(port, ch))
797 			continue; /* Ignore character */
798 
799 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
800 				 ch, flag);
801 	}
802 
803 	tty_flip_buffer_push(&port->state->port);
804 }
805 
806 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
807 {
808 	struct s3c24xx_uart_port *ourport = dev_id;
809 	struct uart_port *port = &ourport->port;
810 	unsigned long flags;
811 
812 	spin_lock_irqsave(&port->lock, flags);
813 	s3c24xx_serial_rx_drain_fifo(ourport);
814 	spin_unlock_irqrestore(&port->lock, flags);
815 
816 	return IRQ_HANDLED;
817 }
818 
819 
820 static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id)
821 {
822 	struct s3c24xx_uart_port *ourport = dev_id;
823 
824 	if (ourport->dma && ourport->dma->rx_chan)
825 		return s3c24xx_serial_rx_chars_dma(dev_id);
826 	return s3c24xx_serial_rx_chars_pio(dev_id);
827 }
828 
829 static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
830 {
831 	struct s3c24xx_uart_port *ourport = id;
832 	struct uart_port *port = &ourport->port;
833 	struct circ_buf *xmit = &port->state->xmit;
834 	unsigned long flags;
835 	int count, dma_count = 0;
836 
837 	spin_lock_irqsave(&port->lock, flags);
838 
839 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
840 
841 	if (ourport->dma && ourport->dma->tx_chan &&
842 	    count >= ourport->min_dma_size) {
843 		int align = dma_get_cache_alignment() -
844 			(xmit->tail & (dma_get_cache_alignment() - 1));
845 		if (count-align >= ourport->min_dma_size) {
846 			dma_count = count-align;
847 			count = align;
848 		}
849 	}
850 
851 	if (port->x_char) {
852 		wr_reg(port, S3C2410_UTXH, port->x_char);
853 		port->icount.tx++;
854 		port->x_char = 0;
855 		goto out;
856 	}
857 
858 	/* if there isn't anything more to transmit, or the uart is now
859 	 * stopped, disable the uart and exit
860 	 */
861 
862 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
863 		s3c24xx_serial_stop_tx(port);
864 		goto out;
865 	}
866 
867 	/* try and drain the buffer... */
868 
869 	if (count > port->fifosize) {
870 		count = port->fifosize;
871 		dma_count = 0;
872 	}
873 
874 	while (!uart_circ_empty(xmit) && count > 0) {
875 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
876 			break;
877 
878 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
879 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
880 		port->icount.tx++;
881 		count--;
882 	}
883 
884 	if (!count && dma_count) {
885 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
886 		goto out;
887 	}
888 
889 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
890 		spin_unlock(&port->lock);
891 		uart_write_wakeup(port);
892 		spin_lock(&port->lock);
893 	}
894 
895 	if (uart_circ_empty(xmit))
896 		s3c24xx_serial_stop_tx(port);
897 
898 out:
899 	spin_unlock_irqrestore(&port->lock, flags);
900 	return IRQ_HANDLED;
901 }
902 
903 /* interrupt handler for s3c64xx and later SoC's.*/
904 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
905 {
906 	struct s3c24xx_uart_port *ourport = id;
907 	struct uart_port *port = &ourport->port;
908 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
909 	irqreturn_t ret = IRQ_HANDLED;
910 
911 	if (pend & S3C64XX_UINTM_RXD_MSK) {
912 		ret = s3c24xx_serial_rx_chars(irq, id);
913 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
914 	}
915 	if (pend & S3C64XX_UINTM_TXD_MSK) {
916 		ret = s3c24xx_serial_tx_chars(irq, id);
917 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
918 	}
919 	return ret;
920 }
921 
922 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
923 {
924 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
925 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
926 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
927 
928 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
929 		if ((ufstat & info->tx_fifomask) != 0 ||
930 		    (ufstat & info->tx_fifofull))
931 			return 0;
932 
933 		return 1;
934 	}
935 
936 	return s3c24xx_serial_txempty_nofifo(port);
937 }
938 
939 /* no modem control lines */
940 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
941 {
942 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
943 
944 	if (umstat & S3C2410_UMSTAT_CTS)
945 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
946 	else
947 		return TIOCM_CAR | TIOCM_DSR;
948 }
949 
950 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
951 {
952 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
953 
954 	if (mctrl & TIOCM_RTS)
955 		umcon |= S3C2410_UMCOM_RTS_LOW;
956 	else
957 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
958 
959 	wr_regl(port, S3C2410_UMCON, umcon);
960 }
961 
962 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
963 {
964 	unsigned long flags;
965 	unsigned int ucon;
966 
967 	spin_lock_irqsave(&port->lock, flags);
968 
969 	ucon = rd_regl(port, S3C2410_UCON);
970 
971 	if (break_state)
972 		ucon |= S3C2410_UCON_SBREAK;
973 	else
974 		ucon &= ~S3C2410_UCON_SBREAK;
975 
976 	wr_regl(port, S3C2410_UCON, ucon);
977 
978 	spin_unlock_irqrestore(&port->lock, flags);
979 }
980 
981 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
982 {
983 	struct s3c24xx_uart_dma	*dma = p->dma;
984 	struct dma_slave_caps dma_caps;
985 	const char *reason = NULL;
986 	int ret;
987 
988 	/* Default slave configuration parameters */
989 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
990 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
991 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
992 	dma->rx_conf.src_maxburst	= 1;
993 
994 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
995 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
996 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
997 	dma->tx_conf.dst_maxburst	= 1;
998 
999 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
1000 
1001 	if (IS_ERR(dma->rx_chan)) {
1002 		reason = "DMA RX channel request failed";
1003 		ret = PTR_ERR(dma->rx_chan);
1004 		goto err_warn;
1005 	}
1006 
1007 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1008 	if (ret < 0 ||
1009 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1010 		reason = "insufficient DMA RX engine capabilities";
1011 		ret = -EOPNOTSUPP;
1012 		goto err_release_rx;
1013 	}
1014 
1015 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1016 
1017 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1018 	if (IS_ERR(dma->tx_chan)) {
1019 		reason = "DMA TX channel request failed";
1020 		ret = PTR_ERR(dma->tx_chan);
1021 		goto err_release_rx;
1022 	}
1023 
1024 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1025 	if (ret < 0 ||
1026 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1027 		reason = "insufficient DMA TX engine capabilities";
1028 		ret = -EOPNOTSUPP;
1029 		goto err_release_tx;
1030 	}
1031 
1032 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1033 
1034 	/* RX buffer */
1035 	dma->rx_size = PAGE_SIZE;
1036 
1037 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1038 	if (!dma->rx_buf) {
1039 		ret = -ENOMEM;
1040 		goto err_release_tx;
1041 	}
1042 
1043 	dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf,
1044 				dma->rx_size, DMA_FROM_DEVICE);
1045 	if (dma_mapping_error(p->port.dev, dma->rx_addr)) {
1046 		reason = "DMA mapping error for RX buffer";
1047 		ret = -EIO;
1048 		goto err_free_rx;
1049 	}
1050 
1051 	/* TX buffer */
1052 	dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf,
1053 				UART_XMIT_SIZE, DMA_TO_DEVICE);
1054 	if (dma_mapping_error(p->port.dev, dma->tx_addr)) {
1055 		reason = "DMA mapping error for TX buffer";
1056 		ret = -EIO;
1057 		goto err_unmap_rx;
1058 	}
1059 
1060 	return 0;
1061 
1062 err_unmap_rx:
1063 	dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size,
1064 			 DMA_FROM_DEVICE);
1065 err_free_rx:
1066 	kfree(dma->rx_buf);
1067 err_release_tx:
1068 	dma_release_channel(dma->tx_chan);
1069 err_release_rx:
1070 	dma_release_channel(dma->rx_chan);
1071 err_warn:
1072 	if (reason)
1073 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1074 	return ret;
1075 }
1076 
1077 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1078 {
1079 	struct s3c24xx_uart_dma	*dma = p->dma;
1080 
1081 	if (dma->rx_chan) {
1082 		dmaengine_terminate_all(dma->rx_chan);
1083 		dma_unmap_single(p->port.dev, dma->rx_addr,
1084 				dma->rx_size, DMA_FROM_DEVICE);
1085 		kfree(dma->rx_buf);
1086 		dma_release_channel(dma->rx_chan);
1087 		dma->rx_chan = NULL;
1088 	}
1089 
1090 	if (dma->tx_chan) {
1091 		dmaengine_terminate_all(dma->tx_chan);
1092 		dma_unmap_single(p->port.dev, dma->tx_addr,
1093 				UART_XMIT_SIZE, DMA_TO_DEVICE);
1094 		dma_release_channel(dma->tx_chan);
1095 		dma->tx_chan = NULL;
1096 	}
1097 }
1098 
1099 static void s3c24xx_serial_shutdown(struct uart_port *port)
1100 {
1101 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1102 
1103 	if (ourport->tx_claimed) {
1104 		if (!s3c24xx_serial_has_interrupt_mask(port))
1105 			free_irq(ourport->tx_irq, ourport);
1106 		ourport->tx_enabled = 0;
1107 		ourport->tx_claimed = 0;
1108 		ourport->tx_mode = 0;
1109 	}
1110 
1111 	if (ourport->rx_claimed) {
1112 		if (!s3c24xx_serial_has_interrupt_mask(port))
1113 			free_irq(ourport->rx_irq, ourport);
1114 		ourport->rx_claimed = 0;
1115 		ourport->rx_enabled = 0;
1116 	}
1117 
1118 	/* Clear pending interrupts and mask all interrupts */
1119 	if (s3c24xx_serial_has_interrupt_mask(port)) {
1120 		free_irq(port->irq, ourport);
1121 
1122 		wr_regl(port, S3C64XX_UINTP, 0xf);
1123 		wr_regl(port, S3C64XX_UINTM, 0xf);
1124 	}
1125 
1126 	if (ourport->dma)
1127 		s3c24xx_serial_release_dma(ourport);
1128 
1129 	ourport->tx_in_progress = 0;
1130 }
1131 
1132 static int s3c24xx_serial_startup(struct uart_port *port)
1133 {
1134 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1135 	int ret;
1136 
1137 	ourport->rx_enabled = 1;
1138 
1139 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
1140 			  s3c24xx_serial_portname(port), ourport);
1141 
1142 	if (ret != 0) {
1143 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1144 		return ret;
1145 	}
1146 
1147 	ourport->rx_claimed = 1;
1148 
1149 	dev_dbg(port->dev, "requesting tx irq...\n");
1150 
1151 	ourport->tx_enabled = 1;
1152 
1153 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
1154 			  s3c24xx_serial_portname(port), ourport);
1155 
1156 	if (ret) {
1157 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1158 		goto err;
1159 	}
1160 
1161 	ourport->tx_claimed = 1;
1162 
1163 	/* the port reset code should have done the correct
1164 	 * register setup for the port controls
1165 	 */
1166 
1167 	return ret;
1168 
1169 err:
1170 	s3c24xx_serial_shutdown(port);
1171 	return ret;
1172 }
1173 
1174 static int s3c64xx_serial_startup(struct uart_port *port)
1175 {
1176 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1177 	unsigned long flags;
1178 	unsigned int ufcon;
1179 	int ret;
1180 
1181 	wr_regl(port, S3C64XX_UINTM, 0xf);
1182 	if (ourport->dma) {
1183 		ret = s3c24xx_serial_request_dma(ourport);
1184 		if (ret < 0) {
1185 			devm_kfree(port->dev, ourport->dma);
1186 			ourport->dma = NULL;
1187 		}
1188 	}
1189 
1190 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1191 			  s3c24xx_serial_portname(port), ourport);
1192 	if (ret) {
1193 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1194 		return ret;
1195 	}
1196 
1197 	/* For compatibility with s3c24xx Soc's */
1198 	ourport->rx_enabled = 1;
1199 	ourport->rx_claimed = 1;
1200 	ourport->tx_enabled = 0;
1201 	ourport->tx_claimed = 1;
1202 
1203 	spin_lock_irqsave(&port->lock, flags);
1204 
1205 	ufcon = rd_regl(port, S3C2410_UFCON);
1206 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1207 	if (!uart_console(port))
1208 		ufcon |= S3C2410_UFCON_RESETTX;
1209 	wr_regl(port, S3C2410_UFCON, ufcon);
1210 
1211 	enable_rx_pio(ourport);
1212 
1213 	spin_unlock_irqrestore(&port->lock, flags);
1214 
1215 	/* Enable Rx Interrupt */
1216 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1217 
1218 	return ret;
1219 }
1220 
1221 /* power power management control */
1222 
1223 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1224 			      unsigned int old)
1225 {
1226 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1227 	int timeout = 10000;
1228 
1229 	ourport->pm_level = level;
1230 
1231 	switch (level) {
1232 	case 3:
1233 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1234 			udelay(100);
1235 
1236 		if (!IS_ERR(ourport->baudclk))
1237 			clk_disable_unprepare(ourport->baudclk);
1238 
1239 		clk_disable_unprepare(ourport->clk);
1240 		break;
1241 
1242 	case 0:
1243 		clk_prepare_enable(ourport->clk);
1244 
1245 		if (!IS_ERR(ourport->baudclk))
1246 			clk_prepare_enable(ourport->baudclk);
1247 
1248 		break;
1249 	default:
1250 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1251 	}
1252 }
1253 
1254 /* baud rate calculation
1255  *
1256  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1257  * of different sources, including the peripheral clock ("pclk") and an
1258  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1259  * with a programmable extra divisor.
1260  *
1261  * The following code goes through the clock sources, and calculates the
1262  * baud clocks (and the resultant actual baud rates) and then tries to
1263  * pick the closest one and select that.
1264  *
1265  */
1266 
1267 #define MAX_CLK_NAME_LENGTH 15
1268 
1269 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1270 {
1271 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1272 	unsigned int ucon;
1273 
1274 	if (info->num_clks == 1)
1275 		return 0;
1276 
1277 	ucon = rd_regl(port, S3C2410_UCON);
1278 	ucon &= info->clksel_mask;
1279 	return ucon >> info->clksel_shift;
1280 }
1281 
1282 static void s3c24xx_serial_setsource(struct uart_port *port,
1283 			unsigned int clk_sel)
1284 {
1285 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1286 	unsigned int ucon;
1287 
1288 	if (info->num_clks == 1)
1289 		return;
1290 
1291 	ucon = rd_regl(port, S3C2410_UCON);
1292 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1293 		return;
1294 
1295 	ucon &= ~info->clksel_mask;
1296 	ucon |= clk_sel << info->clksel_shift;
1297 	wr_regl(port, S3C2410_UCON, ucon);
1298 }
1299 
1300 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1301 			unsigned int req_baud, struct clk **best_clk,
1302 			unsigned int *clk_num)
1303 {
1304 	struct s3c24xx_uart_info *info = ourport->info;
1305 	struct clk *clk;
1306 	unsigned long rate;
1307 	unsigned int cnt, baud, quot, best_quot = 0;
1308 	char clkname[MAX_CLK_NAME_LENGTH];
1309 	int calc_deviation, deviation = (1 << 30) - 1;
1310 
1311 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1312 		/* Keep selected clock if provided */
1313 		if (ourport->cfg->clk_sel &&
1314 			!(ourport->cfg->clk_sel & (1 << cnt)))
1315 			continue;
1316 
1317 		sprintf(clkname, "clk_uart_baud%d", cnt);
1318 		clk = clk_get(ourport->port.dev, clkname);
1319 		if (IS_ERR(clk))
1320 			continue;
1321 
1322 		rate = clk_get_rate(clk);
1323 		if (!rate)
1324 			continue;
1325 
1326 		if (ourport->info->has_divslot) {
1327 			unsigned long div = rate / req_baud;
1328 
1329 			/* The UDIVSLOT register on the newer UARTs allows us to
1330 			 * get a divisor adjustment of 1/16th on the baud clock.
1331 			 *
1332 			 * We don't keep the UDIVSLOT value (the 16ths we
1333 			 * calculated by not multiplying the baud by 16) as it
1334 			 * is easy enough to recalculate.
1335 			 */
1336 
1337 			quot = div / 16;
1338 			baud = rate / div;
1339 		} else {
1340 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1341 			baud = rate / (quot * 16);
1342 		}
1343 		quot--;
1344 
1345 		calc_deviation = req_baud - baud;
1346 		if (calc_deviation < 0)
1347 			calc_deviation = -calc_deviation;
1348 
1349 		if (calc_deviation < deviation) {
1350 			*best_clk = clk;
1351 			best_quot = quot;
1352 			*clk_num = cnt;
1353 			deviation = calc_deviation;
1354 		}
1355 	}
1356 
1357 	return best_quot;
1358 }
1359 
1360 /* udivslot_table[]
1361  *
1362  * This table takes the fractional value of the baud divisor and gives
1363  * the recommended setting for the UDIVSLOT register.
1364  */
1365 static u16 udivslot_table[16] = {
1366 	[0] = 0x0000,
1367 	[1] = 0x0080,
1368 	[2] = 0x0808,
1369 	[3] = 0x0888,
1370 	[4] = 0x2222,
1371 	[5] = 0x4924,
1372 	[6] = 0x4A52,
1373 	[7] = 0x54AA,
1374 	[8] = 0x5555,
1375 	[9] = 0xD555,
1376 	[10] = 0xD5D5,
1377 	[11] = 0xDDD5,
1378 	[12] = 0xDDDD,
1379 	[13] = 0xDFDD,
1380 	[14] = 0xDFDF,
1381 	[15] = 0xFFDF,
1382 };
1383 
1384 static void s3c24xx_serial_set_termios(struct uart_port *port,
1385 				       struct ktermios *termios,
1386 				       struct ktermios *old)
1387 {
1388 	struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1389 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1390 	struct clk *clk = ERR_PTR(-EINVAL);
1391 	unsigned long flags;
1392 	unsigned int baud, quot, clk_sel = 0;
1393 	unsigned int ulcon;
1394 	unsigned int umcon;
1395 	unsigned int udivslot = 0;
1396 
1397 	/*
1398 	 * We don't support modem control lines.
1399 	 */
1400 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1401 	termios->c_cflag |= CLOCAL;
1402 
1403 	/*
1404 	 * Ask the core to calculate the divisor for us.
1405 	 */
1406 
1407 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1408 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1409 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1410 		quot = port->custom_divisor;
1411 	if (IS_ERR(clk))
1412 		return;
1413 
1414 	/* check to see if we need  to change clock source */
1415 
1416 	if (ourport->baudclk != clk) {
1417 		clk_prepare_enable(clk);
1418 
1419 		s3c24xx_serial_setsource(port, clk_sel);
1420 
1421 		if (!IS_ERR(ourport->baudclk)) {
1422 			clk_disable_unprepare(ourport->baudclk);
1423 			ourport->baudclk = ERR_PTR(-EINVAL);
1424 		}
1425 
1426 		ourport->baudclk = clk;
1427 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1428 	}
1429 
1430 	if (ourport->info->has_divslot) {
1431 		unsigned int div = ourport->baudclk_rate / baud;
1432 
1433 		if (cfg->has_fracval) {
1434 			udivslot = (div & 15);
1435 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1436 		} else {
1437 			udivslot = udivslot_table[div & 15];
1438 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1439 				udivslot, div & 15);
1440 		}
1441 	}
1442 
1443 	switch (termios->c_cflag & CSIZE) {
1444 	case CS5:
1445 		dev_dbg(port->dev, "config: 5bits/char\n");
1446 		ulcon = S3C2410_LCON_CS5;
1447 		break;
1448 	case CS6:
1449 		dev_dbg(port->dev, "config: 6bits/char\n");
1450 		ulcon = S3C2410_LCON_CS6;
1451 		break;
1452 	case CS7:
1453 		dev_dbg(port->dev, "config: 7bits/char\n");
1454 		ulcon = S3C2410_LCON_CS7;
1455 		break;
1456 	case CS8:
1457 	default:
1458 		dev_dbg(port->dev, "config: 8bits/char\n");
1459 		ulcon = S3C2410_LCON_CS8;
1460 		break;
1461 	}
1462 
1463 	/* preserve original lcon IR settings */
1464 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1465 
1466 	if (termios->c_cflag & CSTOPB)
1467 		ulcon |= S3C2410_LCON_STOPB;
1468 
1469 	if (termios->c_cflag & PARENB) {
1470 		if (termios->c_cflag & PARODD)
1471 			ulcon |= S3C2410_LCON_PODD;
1472 		else
1473 			ulcon |= S3C2410_LCON_PEVEN;
1474 	} else {
1475 		ulcon |= S3C2410_LCON_PNONE;
1476 	}
1477 
1478 	spin_lock_irqsave(&port->lock, flags);
1479 
1480 	dev_dbg(port->dev,
1481 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1482 		ulcon, quot, udivslot);
1483 
1484 	wr_regl(port, S3C2410_ULCON, ulcon);
1485 	wr_regl(port, S3C2410_UBRDIV, quot);
1486 
1487 	port->status &= ~UPSTAT_AUTOCTS;
1488 
1489 	umcon = rd_regl(port, S3C2410_UMCON);
1490 	if (termios->c_cflag & CRTSCTS) {
1491 		umcon |= S3C2410_UMCOM_AFC;
1492 		/* Disable RTS when RX FIFO contains 63 bytes */
1493 		umcon &= ~S3C2412_UMCON_AFC_8;
1494 		port->status = UPSTAT_AUTOCTS;
1495 	} else {
1496 		umcon &= ~S3C2410_UMCOM_AFC;
1497 	}
1498 	wr_regl(port, S3C2410_UMCON, umcon);
1499 
1500 	if (ourport->info->has_divslot)
1501 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1502 
1503 	dev_dbg(port->dev,
1504 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1505 		rd_regl(port, S3C2410_ULCON),
1506 		rd_regl(port, S3C2410_UCON),
1507 		rd_regl(port, S3C2410_UFCON));
1508 
1509 	/*
1510 	 * Update the per-port timeout.
1511 	 */
1512 	uart_update_timeout(port, termios->c_cflag, baud);
1513 
1514 	/*
1515 	 * Which character status flags are we interested in?
1516 	 */
1517 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1518 	if (termios->c_iflag & INPCK)
1519 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1520 			S3C2410_UERSTAT_PARITY;
1521 	/*
1522 	 * Which character status flags should we ignore?
1523 	 */
1524 	port->ignore_status_mask = 0;
1525 	if (termios->c_iflag & IGNPAR)
1526 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1527 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1528 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1529 
1530 	/*
1531 	 * Ignore all characters if CREAD is not set.
1532 	 */
1533 	if ((termios->c_cflag & CREAD) == 0)
1534 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1535 
1536 	spin_unlock_irqrestore(&port->lock, flags);
1537 }
1538 
1539 static const char *s3c24xx_serial_type(struct uart_port *port)
1540 {
1541 	switch (port->type) {
1542 	case PORT_S3C2410:
1543 		return "S3C2410";
1544 	case PORT_S3C2440:
1545 		return "S3C2440";
1546 	case PORT_S3C2412:
1547 		return "S3C2412";
1548 	case PORT_S3C6400:
1549 		return "S3C6400/10";
1550 	default:
1551 		return NULL;
1552 	}
1553 }
1554 
1555 #define MAP_SIZE (0x100)
1556 
1557 static void s3c24xx_serial_release_port(struct uart_port *port)
1558 {
1559 	release_mem_region(port->mapbase, MAP_SIZE);
1560 }
1561 
1562 static int s3c24xx_serial_request_port(struct uart_port *port)
1563 {
1564 	const char *name = s3c24xx_serial_portname(port);
1565 
1566 	return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
1567 }
1568 
1569 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1570 {
1571 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1572 
1573 	if (flags & UART_CONFIG_TYPE &&
1574 	    s3c24xx_serial_request_port(port) == 0)
1575 		port->type = info->type;
1576 }
1577 
1578 /*
1579  * verify the new serial_struct (for TIOCSSERIAL).
1580  */
1581 static int
1582 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1583 {
1584 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1585 
1586 	if (ser->type != PORT_UNKNOWN && ser->type != info->type)
1587 		return -EINVAL;
1588 
1589 	return 0;
1590 }
1591 
1592 
1593 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1594 
1595 static struct console s3c24xx_serial_console;
1596 
1597 static int __init s3c24xx_serial_console_init(void)
1598 {
1599 	register_console(&s3c24xx_serial_console);
1600 	return 0;
1601 }
1602 console_initcall(s3c24xx_serial_console_init);
1603 
1604 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1605 #else
1606 #define S3C24XX_SERIAL_CONSOLE NULL
1607 #endif
1608 
1609 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1610 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1611 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1612 			 unsigned char c);
1613 #endif
1614 
1615 static struct uart_ops s3c24xx_serial_ops = {
1616 	.pm		= s3c24xx_serial_pm,
1617 	.tx_empty	= s3c24xx_serial_tx_empty,
1618 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1619 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1620 	.stop_tx	= s3c24xx_serial_stop_tx,
1621 	.start_tx	= s3c24xx_serial_start_tx,
1622 	.stop_rx	= s3c24xx_serial_stop_rx,
1623 	.break_ctl	= s3c24xx_serial_break_ctl,
1624 	.startup	= s3c24xx_serial_startup,
1625 	.shutdown	= s3c24xx_serial_shutdown,
1626 	.set_termios	= s3c24xx_serial_set_termios,
1627 	.type		= s3c24xx_serial_type,
1628 	.release_port	= s3c24xx_serial_release_port,
1629 	.request_port	= s3c24xx_serial_request_port,
1630 	.config_port	= s3c24xx_serial_config_port,
1631 	.verify_port	= s3c24xx_serial_verify_port,
1632 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1633 	.poll_get_char = s3c24xx_serial_get_poll_char,
1634 	.poll_put_char = s3c24xx_serial_put_poll_char,
1635 #endif
1636 };
1637 
1638 static struct uart_driver s3c24xx_uart_drv = {
1639 	.owner		= THIS_MODULE,
1640 	.driver_name	= "s3c2410_serial",
1641 	.nr		= CONFIG_SERIAL_SAMSUNG_UARTS,
1642 	.cons		= S3C24XX_SERIAL_CONSOLE,
1643 	.dev_name	= S3C24XX_SERIAL_NAME,
1644 	.major		= S3C24XX_SERIAL_MAJOR,
1645 	.minor		= S3C24XX_SERIAL_MINOR,
1646 };
1647 
1648 #define __PORT_LOCK_UNLOCKED(i) \
1649 	__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[i].port.lock)
1650 static struct s3c24xx_uart_port
1651 s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
1652 	[0] = {
1653 		.port = {
1654 			.lock		= __PORT_LOCK_UNLOCKED(0),
1655 			.iotype		= UPIO_MEM,
1656 			.uartclk	= 0,
1657 			.fifosize	= 16,
1658 			.ops		= &s3c24xx_serial_ops,
1659 			.flags		= UPF_BOOT_AUTOCONF,
1660 			.line		= 0,
1661 		}
1662 	},
1663 	[1] = {
1664 		.port = {
1665 			.lock		= __PORT_LOCK_UNLOCKED(1),
1666 			.iotype		= UPIO_MEM,
1667 			.uartclk	= 0,
1668 			.fifosize	= 16,
1669 			.ops		= &s3c24xx_serial_ops,
1670 			.flags		= UPF_BOOT_AUTOCONF,
1671 			.line		= 1,
1672 		}
1673 	},
1674 #if CONFIG_SERIAL_SAMSUNG_UARTS > 2
1675 
1676 	[2] = {
1677 		.port = {
1678 			.lock		= __PORT_LOCK_UNLOCKED(2),
1679 			.iotype		= UPIO_MEM,
1680 			.uartclk	= 0,
1681 			.fifosize	= 16,
1682 			.ops		= &s3c24xx_serial_ops,
1683 			.flags		= UPF_BOOT_AUTOCONF,
1684 			.line		= 2,
1685 		}
1686 	},
1687 #endif
1688 #if CONFIG_SERIAL_SAMSUNG_UARTS > 3
1689 	[3] = {
1690 		.port = {
1691 			.lock		= __PORT_LOCK_UNLOCKED(3),
1692 			.iotype		= UPIO_MEM,
1693 			.uartclk	= 0,
1694 			.fifosize	= 16,
1695 			.ops		= &s3c24xx_serial_ops,
1696 			.flags		= UPF_BOOT_AUTOCONF,
1697 			.line		= 3,
1698 		}
1699 	}
1700 #endif
1701 };
1702 #undef __PORT_LOCK_UNLOCKED
1703 
1704 /* s3c24xx_serial_resetport
1705  *
1706  * reset the fifos and other the settings.
1707  */
1708 
1709 static void s3c24xx_serial_resetport(struct uart_port *port,
1710 				   struct s3c2410_uartcfg *cfg)
1711 {
1712 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1713 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1714 	unsigned int ucon_mask;
1715 
1716 	ucon_mask = info->clksel_mask;
1717 	if (info->type == PORT_S3C2440)
1718 		ucon_mask |= S3C2440_UCON0_DIVMASK;
1719 
1720 	ucon &= ucon_mask;
1721 	wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
1722 
1723 	/* reset both fifos */
1724 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1725 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1726 
1727 	/* some delay is required after fifo reset */
1728 	udelay(1);
1729 }
1730 
1731 
1732 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1733 
1734 static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1735 					     unsigned long val, void *data)
1736 {
1737 	struct s3c24xx_uart_port *port;
1738 	struct uart_port *uport;
1739 
1740 	port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1741 	uport = &port->port;
1742 
1743 	/* check to see if port is enabled */
1744 
1745 	if (port->pm_level != 0)
1746 		return 0;
1747 
1748 	/* try and work out if the baudrate is changing, we can detect
1749 	 * a change in rate, but we do not have support for detecting
1750 	 * a disturbance in the clock-rate over the change.
1751 	 */
1752 
1753 	if (IS_ERR(port->baudclk))
1754 		goto exit;
1755 
1756 	if (port->baudclk_rate == clk_get_rate(port->baudclk))
1757 		goto exit;
1758 
1759 	if (val == CPUFREQ_PRECHANGE) {
1760 		/* we should really shut the port down whilst the
1761 		 * frequency change is in progress.
1762 		 */
1763 
1764 	} else if (val == CPUFREQ_POSTCHANGE) {
1765 		struct ktermios *termios;
1766 		struct tty_struct *tty;
1767 
1768 		if (uport->state == NULL)
1769 			goto exit;
1770 
1771 		tty = uport->state->port.tty;
1772 
1773 		if (tty == NULL)
1774 			goto exit;
1775 
1776 		termios = &tty->termios;
1777 
1778 		if (termios == NULL) {
1779 			dev_warn(uport->dev, "%s: no termios?\n", __func__);
1780 			goto exit;
1781 		}
1782 
1783 		s3c24xx_serial_set_termios(uport, termios, NULL);
1784 	}
1785 
1786 exit:
1787 	return 0;
1788 }
1789 
1790 static inline int
1791 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1792 {
1793 	port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1794 
1795 	return cpufreq_register_notifier(&port->freq_transition,
1796 					 CPUFREQ_TRANSITION_NOTIFIER);
1797 }
1798 
1799 static inline void
1800 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1801 {
1802 	cpufreq_unregister_notifier(&port->freq_transition,
1803 				    CPUFREQ_TRANSITION_NOTIFIER);
1804 }
1805 
1806 #else
1807 static inline int
1808 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1809 {
1810 	return 0;
1811 }
1812 
1813 static inline void
1814 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1815 {
1816 }
1817 #endif
1818 
1819 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1820 {
1821 	struct device *dev = ourport->port.dev;
1822 	struct s3c24xx_uart_info *info = ourport->info;
1823 	char clk_name[MAX_CLK_NAME_LENGTH];
1824 	unsigned int clk_sel;
1825 	struct clk *clk;
1826 	int clk_num;
1827 	int ret;
1828 
1829 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1830 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1831 		if (!(clk_sel & (1 << clk_num)))
1832 			continue;
1833 
1834 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1835 		clk = clk_get(dev, clk_name);
1836 		if (IS_ERR(clk))
1837 			continue;
1838 
1839 		ret = clk_prepare_enable(clk);
1840 		if (ret) {
1841 			clk_put(clk);
1842 			continue;
1843 		}
1844 
1845 		ourport->baudclk = clk;
1846 		ourport->baudclk_rate = clk_get_rate(clk);
1847 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1848 
1849 		return 0;
1850 	}
1851 
1852 	return -EINVAL;
1853 }
1854 
1855 /* s3c24xx_serial_init_port
1856  *
1857  * initialise a single serial port from the platform device given
1858  */
1859 
1860 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1861 				    struct platform_device *platdev)
1862 {
1863 	struct uart_port *port = &ourport->port;
1864 	struct s3c2410_uartcfg *cfg = ourport->cfg;
1865 	struct resource *res;
1866 	int ret;
1867 
1868 	if (platdev == NULL)
1869 		return -ENODEV;
1870 
1871 	if (port->mapbase != 0)
1872 		return -EINVAL;
1873 
1874 	/* setup info for port */
1875 	port->dev	= &platdev->dev;
1876 
1877 	/* Startup sequence is different for s3c64xx and higher SoC's */
1878 	if (s3c24xx_serial_has_interrupt_mask(port))
1879 		s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
1880 
1881 	port->uartclk = 1;
1882 
1883 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1884 		dev_dbg(port->dev, "enabling flow control\n");
1885 		port->flags |= UPF_CONS_FLOW;
1886 	}
1887 
1888 	/* sort our the physical and virtual addresses for each UART */
1889 
1890 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1891 	if (res == NULL) {
1892 		dev_err(port->dev, "failed to find memory resource for uart\n");
1893 		return -EINVAL;
1894 	}
1895 
1896 	dev_dbg(port->dev, "resource %pR)\n", res);
1897 
1898 	port->membase = devm_ioremap(port->dev, res->start, resource_size(res));
1899 	if (!port->membase) {
1900 		dev_err(port->dev, "failed to remap controller address\n");
1901 		return -EBUSY;
1902 	}
1903 
1904 	port->mapbase = res->start;
1905 	ret = platform_get_irq(platdev, 0);
1906 	if (ret < 0)
1907 		port->irq = 0;
1908 	else {
1909 		port->irq = ret;
1910 		ourport->rx_irq = ret;
1911 		ourport->tx_irq = ret + 1;
1912 	}
1913 
1914 	ret = platform_get_irq(platdev, 1);
1915 	if (ret > 0)
1916 		ourport->tx_irq = ret;
1917 	/*
1918 	 * DMA is currently supported only on DT platforms, if DMA properties
1919 	 * are specified.
1920 	 */
1921 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1922 						     "dmas", NULL)) {
1923 		ourport->dma = devm_kzalloc(port->dev,
1924 					    sizeof(*ourport->dma),
1925 					    GFP_KERNEL);
1926 		if (!ourport->dma) {
1927 			ret = -ENOMEM;
1928 			goto err;
1929 		}
1930 	}
1931 
1932 	ourport->clk	= clk_get(&platdev->dev, "uart");
1933 	if (IS_ERR(ourport->clk)) {
1934 		pr_err("%s: Controller clock not found\n",
1935 				dev_name(&platdev->dev));
1936 		ret = PTR_ERR(ourport->clk);
1937 		goto err;
1938 	}
1939 
1940 	ret = clk_prepare_enable(ourport->clk);
1941 	if (ret) {
1942 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1943 		clk_put(ourport->clk);
1944 		goto err;
1945 	}
1946 
1947 	ret = s3c24xx_serial_enable_baudclk(ourport);
1948 	if (ret)
1949 		pr_warn("uart: failed to enable baudclk\n");
1950 
1951 	/* Keep all interrupts masked and cleared */
1952 	if (s3c24xx_serial_has_interrupt_mask(port)) {
1953 		wr_regl(port, S3C64XX_UINTM, 0xf);
1954 		wr_regl(port, S3C64XX_UINTP, 0xf);
1955 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1956 	}
1957 
1958 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1959 		&port->mapbase, port->membase, port->irq,
1960 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
1961 
1962 	/* reset the fifos (and setup the uart) */
1963 	s3c24xx_serial_resetport(port, cfg);
1964 
1965 	return 0;
1966 
1967 err:
1968 	port->mapbase = 0;
1969 	return ret;
1970 }
1971 
1972 /* Device driver serial port probe */
1973 
1974 #ifdef CONFIG_OF
1975 static const struct of_device_id s3c24xx_uart_dt_match[];
1976 #endif
1977 
1978 static int probe_index;
1979 
1980 static inline struct s3c24xx_serial_drv_data *s3c24xx_get_driver_data(
1981 			struct platform_device *pdev)
1982 {
1983 #ifdef CONFIG_OF
1984 	if (pdev->dev.of_node) {
1985 		const struct of_device_id *match;
1986 
1987 		match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
1988 		return (struct s3c24xx_serial_drv_data *)match->data;
1989 	}
1990 #endif
1991 	return (struct s3c24xx_serial_drv_data *)
1992 			platform_get_device_id(pdev)->driver_data;
1993 }
1994 
1995 static int s3c24xx_serial_probe(struct platform_device *pdev)
1996 {
1997 	struct device_node *np = pdev->dev.of_node;
1998 	struct s3c24xx_uart_port *ourport;
1999 	int index = probe_index;
2000 	int ret, prop = 0;
2001 
2002 	if (np) {
2003 		ret = of_alias_get_id(np, "serial");
2004 		if (ret >= 0)
2005 			index = ret;
2006 	}
2007 
2008 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2009 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2010 		return -EINVAL;
2011 	}
2012 	ourport = &s3c24xx_serial_ports[index];
2013 
2014 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2015 	if (!ourport->drv_data) {
2016 		dev_err(&pdev->dev, "could not find driver data\n");
2017 		return -ENODEV;
2018 	}
2019 
2020 	ourport->baudclk = ERR_PTR(-EINVAL);
2021 	ourport->info = ourport->drv_data->info;
2022 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2023 			dev_get_platdata(&pdev->dev) :
2024 			ourport->drv_data->def_cfg;
2025 
2026 	if (np) {
2027 		of_property_read_u32(np,
2028 			"samsung,uart-fifosize", &ourport->port.fifosize);
2029 
2030 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2031 			switch (prop) {
2032 			case 1:
2033 				ourport->port.iotype = UPIO_MEM;
2034 				break;
2035 			case 4:
2036 				ourport->port.iotype = UPIO_MEM32;
2037 				break;
2038 			default:
2039 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2040 						prop);
2041 				ret = -EINVAL;
2042 				break;
2043 			}
2044 		}
2045 	}
2046 
2047 	if (ourport->drv_data->fifosize[index])
2048 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2049 	else if (ourport->info->fifosize)
2050 		ourport->port.fifosize = ourport->info->fifosize;
2051 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2052 
2053 	/*
2054 	 * DMA transfers must be aligned at least to cache line size,
2055 	 * so find minimal transfer size suitable for DMA mode
2056 	 */
2057 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2058 				    dma_get_cache_alignment());
2059 
2060 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2061 
2062 	ret = s3c24xx_serial_init_port(ourport, pdev);
2063 	if (ret < 0)
2064 		return ret;
2065 
2066 	if (!s3c24xx_uart_drv.state) {
2067 		ret = uart_register_driver(&s3c24xx_uart_drv);
2068 		if (ret < 0) {
2069 			pr_err("Failed to register Samsung UART driver\n");
2070 			return ret;
2071 		}
2072 	}
2073 
2074 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2075 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2076 	platform_set_drvdata(pdev, &ourport->port);
2077 
2078 	/*
2079 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2080 	 * so that a potential re-enablement through the pm-callback overlaps
2081 	 * and keeps the clock enabled in this case.
2082 	 */
2083 	clk_disable_unprepare(ourport->clk);
2084 	if (!IS_ERR(ourport->baudclk))
2085 		clk_disable_unprepare(ourport->baudclk);
2086 
2087 	ret = s3c24xx_serial_cpufreq_register(ourport);
2088 	if (ret < 0)
2089 		dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
2090 
2091 	probe_index++;
2092 
2093 	return 0;
2094 }
2095 
2096 static int s3c24xx_serial_remove(struct platform_device *dev)
2097 {
2098 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2099 
2100 	if (port) {
2101 		s3c24xx_serial_cpufreq_deregister(to_ourport(port));
2102 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2103 	}
2104 
2105 	uart_unregister_driver(&s3c24xx_uart_drv);
2106 
2107 	return 0;
2108 }
2109 
2110 /* UART power management code */
2111 #ifdef CONFIG_PM_SLEEP
2112 static int s3c24xx_serial_suspend(struct device *dev)
2113 {
2114 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2115 
2116 	if (port)
2117 		uart_suspend_port(&s3c24xx_uart_drv, port);
2118 
2119 	return 0;
2120 }
2121 
2122 static int s3c24xx_serial_resume(struct device *dev)
2123 {
2124 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2125 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2126 
2127 	if (port) {
2128 		clk_prepare_enable(ourport->clk);
2129 		if (!IS_ERR(ourport->baudclk))
2130 			clk_prepare_enable(ourport->baudclk);
2131 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2132 		if (!IS_ERR(ourport->baudclk))
2133 			clk_disable_unprepare(ourport->baudclk);
2134 		clk_disable_unprepare(ourport->clk);
2135 
2136 		uart_resume_port(&s3c24xx_uart_drv, port);
2137 	}
2138 
2139 	return 0;
2140 }
2141 
2142 static int s3c24xx_serial_resume_noirq(struct device *dev)
2143 {
2144 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2145 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2146 
2147 	if (port) {
2148 		/* restore IRQ mask */
2149 		if (s3c24xx_serial_has_interrupt_mask(port)) {
2150 			unsigned int uintm = 0xf;
2151 
2152 			if (ourport->tx_enabled)
2153 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2154 			if (ourport->rx_enabled)
2155 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2156 			clk_prepare_enable(ourport->clk);
2157 			if (!IS_ERR(ourport->baudclk))
2158 				clk_prepare_enable(ourport->baudclk);
2159 			wr_regl(port, S3C64XX_UINTM, uintm);
2160 			if (!IS_ERR(ourport->baudclk))
2161 				clk_disable_unprepare(ourport->baudclk);
2162 			clk_disable_unprepare(ourport->clk);
2163 		}
2164 	}
2165 
2166 	return 0;
2167 }
2168 
2169 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2170 	.suspend = s3c24xx_serial_suspend,
2171 	.resume = s3c24xx_serial_resume,
2172 	.resume_noirq = s3c24xx_serial_resume_noirq,
2173 };
2174 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2175 
2176 #else /* !CONFIG_PM_SLEEP */
2177 
2178 #define SERIAL_SAMSUNG_PM_OPS	NULL
2179 #endif /* CONFIG_PM_SLEEP */
2180 
2181 /* Console code */
2182 
2183 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2184 
2185 static struct uart_port *cons_uart;
2186 
2187 static int
2188 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2189 {
2190 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2191 	unsigned long ufstat, utrstat;
2192 
2193 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2194 		/* fifo mode - check amount of data in fifo registers... */
2195 
2196 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2197 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2198 	}
2199 
2200 	/* in non-fifo mode, we go and use the tx buffer empty */
2201 
2202 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2203 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2204 }
2205 
2206 static bool
2207 s3c24xx_port_configured(unsigned int ucon)
2208 {
2209 	/* consider the serial port configured if the tx/rx mode set */
2210 	return (ucon & 0xf) != 0;
2211 }
2212 
2213 #ifdef CONFIG_CONSOLE_POLL
2214 /*
2215  * Console polling routines for writing and reading from the uart while
2216  * in an interrupt or debug context.
2217  */
2218 
2219 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2220 {
2221 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2222 	unsigned int ufstat;
2223 
2224 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2225 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2226 		return NO_POLL_CHAR;
2227 
2228 	return rd_reg(port, S3C2410_URXH);
2229 }
2230 
2231 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2232 		unsigned char c)
2233 {
2234 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2235 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2236 
2237 	/* not possible to xmit on unconfigured port */
2238 	if (!s3c24xx_port_configured(ucon))
2239 		return;
2240 
2241 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2242 		cpu_relax();
2243 	wr_reg(port, S3C2410_UTXH, c);
2244 }
2245 
2246 #endif /* CONFIG_CONSOLE_POLL */
2247 
2248 static void
2249 s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
2250 {
2251 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2252 
2253 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2254 		cpu_relax();
2255 	wr_reg(port, S3C2410_UTXH, ch);
2256 }
2257 
2258 static void
2259 s3c24xx_serial_console_write(struct console *co, const char *s,
2260 			     unsigned int count)
2261 {
2262 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2263 
2264 	/* not possible to xmit on unconfigured port */
2265 	if (!s3c24xx_port_configured(ucon))
2266 		return;
2267 
2268 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2269 }
2270 
2271 static void __init
2272 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2273 			   int *parity, int *bits)
2274 {
2275 	struct clk *clk;
2276 	unsigned int ulcon;
2277 	unsigned int ucon;
2278 	unsigned int ubrdiv;
2279 	unsigned long rate;
2280 	unsigned int clk_sel;
2281 	char clk_name[MAX_CLK_NAME_LENGTH];
2282 
2283 	ulcon  = rd_regl(port, S3C2410_ULCON);
2284 	ucon   = rd_regl(port, S3C2410_UCON);
2285 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2286 
2287 	if (s3c24xx_port_configured(ucon)) {
2288 		switch (ulcon & S3C2410_LCON_CSMASK) {
2289 		case S3C2410_LCON_CS5:
2290 			*bits = 5;
2291 			break;
2292 		case S3C2410_LCON_CS6:
2293 			*bits = 6;
2294 			break;
2295 		case S3C2410_LCON_CS7:
2296 			*bits = 7;
2297 			break;
2298 		case S3C2410_LCON_CS8:
2299 		default:
2300 			*bits = 8;
2301 			break;
2302 		}
2303 
2304 		switch (ulcon & S3C2410_LCON_PMASK) {
2305 		case S3C2410_LCON_PEVEN:
2306 			*parity = 'e';
2307 			break;
2308 
2309 		case S3C2410_LCON_PODD:
2310 			*parity = 'o';
2311 			break;
2312 
2313 		case S3C2410_LCON_PNONE:
2314 		default:
2315 			*parity = 'n';
2316 		}
2317 
2318 		/* now calculate the baud rate */
2319 
2320 		clk_sel = s3c24xx_serial_getsource(port);
2321 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2322 
2323 		clk = clk_get(port->dev, clk_name);
2324 		if (!IS_ERR(clk))
2325 			rate = clk_get_rate(clk);
2326 		else
2327 			rate = 1;
2328 
2329 		*baud = rate / (16 * (ubrdiv + 1));
2330 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2331 	}
2332 
2333 }
2334 
2335 static int __init
2336 s3c24xx_serial_console_setup(struct console *co, char *options)
2337 {
2338 	struct uart_port *port;
2339 	int baud = 9600;
2340 	int bits = 8;
2341 	int parity = 'n';
2342 	int flow = 'n';
2343 
2344 	/* is this a valid port */
2345 
2346 	if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
2347 		co->index = 0;
2348 
2349 	port = &s3c24xx_serial_ports[co->index].port;
2350 
2351 	/* is the port configured? */
2352 
2353 	if (port->mapbase == 0x0)
2354 		return -ENODEV;
2355 
2356 	cons_uart = port;
2357 
2358 	/*
2359 	 * Check whether an invalid uart number has been specified, and
2360 	 * if so, search for the first available port that does have
2361 	 * console support.
2362 	 */
2363 	if (options)
2364 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2365 	else
2366 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2367 
2368 	dev_dbg(port->dev, "baud %d\n", baud);
2369 
2370 	return uart_set_options(port, co, baud, parity, bits, flow);
2371 }
2372 
2373 static struct console s3c24xx_serial_console = {
2374 	.name		= S3C24XX_SERIAL_NAME,
2375 	.device		= uart_console_device,
2376 	.flags		= CON_PRINTBUFFER,
2377 	.index		= -1,
2378 	.write		= s3c24xx_serial_console_write,
2379 	.setup		= s3c24xx_serial_console_setup,
2380 	.data		= &s3c24xx_uart_drv,
2381 };
2382 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2383 
2384 #ifdef CONFIG_CPU_S3C2410
2385 static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
2386 	.info = &(struct s3c24xx_uart_info) {
2387 		.name		= "Samsung S3C2410 UART",
2388 		.type		= PORT_S3C2410,
2389 		.fifosize	= 16,
2390 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2391 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2392 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2393 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2394 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2395 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2396 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2397 		.num_clks	= 2,
2398 		.clksel_mask	= S3C2410_UCON_CLKMASK,
2399 		.clksel_shift	= S3C2410_UCON_CLKSHIFT,
2400 	},
2401 	.def_cfg = &(struct s3c2410_uartcfg) {
2402 		.ucon		= S3C2410_UCON_DEFAULT,
2403 		.ufcon		= S3C2410_UFCON_DEFAULT,
2404 	},
2405 };
2406 #define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
2407 #else
2408 #define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2409 #endif
2410 
2411 #ifdef CONFIG_CPU_S3C2412
2412 static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
2413 	.info = &(struct s3c24xx_uart_info) {
2414 		.name		= "Samsung S3C2412 UART",
2415 		.type		= PORT_S3C2412,
2416 		.fifosize	= 64,
2417 		.has_divslot	= 1,
2418 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2419 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2420 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2421 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2422 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2423 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2424 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2425 		.num_clks	= 4,
2426 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2427 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2428 	},
2429 	.def_cfg = &(struct s3c2410_uartcfg) {
2430 		.ucon		= S3C2410_UCON_DEFAULT,
2431 		.ufcon		= S3C2410_UFCON_DEFAULT,
2432 	},
2433 };
2434 #define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
2435 #else
2436 #define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2437 #endif
2438 
2439 #if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
2440 	defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
2441 static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
2442 	.info = &(struct s3c24xx_uart_info) {
2443 		.name		= "Samsung S3C2440 UART",
2444 		.type		= PORT_S3C2440,
2445 		.fifosize	= 64,
2446 		.has_divslot	= 1,
2447 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2448 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2449 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2450 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2451 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2452 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2453 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2454 		.num_clks	= 4,
2455 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2456 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2457 	},
2458 	.def_cfg = &(struct s3c2410_uartcfg) {
2459 		.ucon		= S3C2410_UCON_DEFAULT,
2460 		.ufcon		= S3C2410_UFCON_DEFAULT,
2461 	},
2462 };
2463 #define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
2464 #else
2465 #define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2466 #endif
2467 
2468 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2469 static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2470 	.info = &(struct s3c24xx_uart_info) {
2471 		.name		= "Samsung S3C6400 UART",
2472 		.type		= PORT_S3C6400,
2473 		.fifosize	= 64,
2474 		.has_divslot	= 1,
2475 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2476 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2477 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2478 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2479 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2480 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2481 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2482 		.num_clks	= 4,
2483 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2484 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2485 	},
2486 	.def_cfg = &(struct s3c2410_uartcfg) {
2487 		.ucon		= S3C2410_UCON_DEFAULT,
2488 		.ufcon		= S3C2410_UFCON_DEFAULT,
2489 	},
2490 };
2491 #define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
2492 #else
2493 #define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2494 #endif
2495 
2496 #ifdef CONFIG_CPU_S5PV210
2497 static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2498 	.info = &(struct s3c24xx_uart_info) {
2499 		.name		= "Samsung S5PV210 UART",
2500 		.type		= PORT_S3C6400,
2501 		.has_divslot	= 1,
2502 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2503 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2504 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2505 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2506 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2507 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2508 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2509 		.num_clks	= 2,
2510 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2511 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2512 	},
2513 	.def_cfg = &(struct s3c2410_uartcfg) {
2514 		.ucon		= S5PV210_UCON_DEFAULT,
2515 		.ufcon		= S5PV210_UFCON_DEFAULT,
2516 	},
2517 	.fifosize = { 256, 64, 16, 16 },
2518 };
2519 #define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
2520 #else
2521 #define S5PV210_SERIAL_DRV_DATA	(kernel_ulong_t)NULL
2522 #endif
2523 
2524 #if defined(CONFIG_ARCH_EXYNOS)
2525 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2526 	.info = &(struct s3c24xx_uart_info) {			\
2527 		.name		= "Samsung Exynos UART",	\
2528 		.type		= PORT_S3C6400,			\
2529 		.has_divslot	= 1,				\
2530 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2531 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2532 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2533 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2534 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2535 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2536 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2537 		.num_clks	= 1,				\
2538 		.clksel_mask	= 0,				\
2539 		.clksel_shift	= 0,				\
2540 	},							\
2541 	.def_cfg = &(struct s3c2410_uartcfg) {			\
2542 		.ucon		= S5PV210_UCON_DEFAULT,		\
2543 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2544 		.has_fracval	= 1,				\
2545 	}							\
2546 
2547 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2548 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2549 	.fifosize = { 256, 64, 16, 16 },
2550 };
2551 
2552 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2553 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2554 	.fifosize = { 64, 256, 16, 256 },
2555 };
2556 
2557 #define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
2558 #define EXYNOS5433_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos5433_serial_drv_data)
2559 #else
2560 #define EXYNOS4210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2561 #define EXYNOS5433_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2562 #endif
2563 
2564 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2565 	{
2566 		.name		= "s3c2410-uart",
2567 		.driver_data	= S3C2410_SERIAL_DRV_DATA,
2568 	}, {
2569 		.name		= "s3c2412-uart",
2570 		.driver_data	= S3C2412_SERIAL_DRV_DATA,
2571 	}, {
2572 		.name		= "s3c2440-uart",
2573 		.driver_data	= S3C2440_SERIAL_DRV_DATA,
2574 	}, {
2575 		.name		= "s3c6400-uart",
2576 		.driver_data	= S3C6400_SERIAL_DRV_DATA,
2577 	}, {
2578 		.name		= "s5pv210-uart",
2579 		.driver_data	= S5PV210_SERIAL_DRV_DATA,
2580 	}, {
2581 		.name		= "exynos4210-uart",
2582 		.driver_data	= EXYNOS4210_SERIAL_DRV_DATA,
2583 	}, {
2584 		.name		= "exynos5433-uart",
2585 		.driver_data	= EXYNOS5433_SERIAL_DRV_DATA,
2586 	},
2587 	{ },
2588 };
2589 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2590 
2591 #ifdef CONFIG_OF
2592 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2593 	{ .compatible = "samsung,s3c2410-uart",
2594 		.data = (void *)S3C2410_SERIAL_DRV_DATA },
2595 	{ .compatible = "samsung,s3c2412-uart",
2596 		.data = (void *)S3C2412_SERIAL_DRV_DATA },
2597 	{ .compatible = "samsung,s3c2440-uart",
2598 		.data = (void *)S3C2440_SERIAL_DRV_DATA },
2599 	{ .compatible = "samsung,s3c6400-uart",
2600 		.data = (void *)S3C6400_SERIAL_DRV_DATA },
2601 	{ .compatible = "samsung,s5pv210-uart",
2602 		.data = (void *)S5PV210_SERIAL_DRV_DATA },
2603 	{ .compatible = "samsung,exynos4210-uart",
2604 		.data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
2605 	{ .compatible = "samsung,exynos5433-uart",
2606 		.data = (void *)EXYNOS5433_SERIAL_DRV_DATA },
2607 	{},
2608 };
2609 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2610 #endif
2611 
2612 static struct platform_driver samsung_serial_driver = {
2613 	.probe		= s3c24xx_serial_probe,
2614 	.remove		= s3c24xx_serial_remove,
2615 	.id_table	= s3c24xx_serial_driver_ids,
2616 	.driver		= {
2617 		.name	= "samsung-uart",
2618 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2619 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2620 	},
2621 };
2622 
2623 module_platform_driver(samsung_serial_driver);
2624 
2625 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2626 /*
2627  * Early console.
2628  */
2629 
2630 static void wr_reg_barrier(struct uart_port *port, u32 reg, u32 val)
2631 {
2632 	switch (port->iotype) {
2633 	case UPIO_MEM:
2634 		writeb(val, portaddr(port, reg));
2635 		break;
2636 	case UPIO_MEM32:
2637 		writel(val, portaddr(port, reg));
2638 		break;
2639 	}
2640 }
2641 
2642 struct samsung_early_console_data {
2643 	u32 txfull_mask;
2644 };
2645 
2646 static void samsung_early_busyuart(struct uart_port *port)
2647 {
2648 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2649 		;
2650 }
2651 
2652 static void samsung_early_busyuart_fifo(struct uart_port *port)
2653 {
2654 	struct samsung_early_console_data *data = port->private_data;
2655 
2656 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2657 		;
2658 }
2659 
2660 static void samsung_early_putc(struct uart_port *port, int c)
2661 {
2662 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2663 		samsung_early_busyuart_fifo(port);
2664 	else
2665 		samsung_early_busyuart(port);
2666 
2667 	wr_reg_barrier(port, S3C2410_UTXH, c);
2668 }
2669 
2670 static void samsung_early_write(struct console *con, const char *s,
2671 				unsigned int n)
2672 {
2673 	struct earlycon_device *dev = con->data;
2674 
2675 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2676 }
2677 
2678 static int __init samsung_early_console_setup(struct earlycon_device *device,
2679 					      const char *opt)
2680 {
2681 	if (!device->port.membase)
2682 		return -ENODEV;
2683 
2684 	device->con->write = samsung_early_write;
2685 	return 0;
2686 }
2687 
2688 /* S3C2410 */
2689 static struct samsung_early_console_data s3c2410_early_console_data = {
2690 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2691 };
2692 
2693 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
2694 					      const char *opt)
2695 {
2696 	device->port.private_data = &s3c2410_early_console_data;
2697 	return samsung_early_console_setup(device, opt);
2698 }
2699 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
2700 			s3c2410_early_console_setup);
2701 
2702 /* S3C2412, S3C2440, S3C64xx */
2703 static struct samsung_early_console_data s3c2440_early_console_data = {
2704 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2705 };
2706 
2707 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2708 					      const char *opt)
2709 {
2710 	device->port.private_data = &s3c2440_early_console_data;
2711 	return samsung_early_console_setup(device, opt);
2712 }
2713 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
2714 			s3c2440_early_console_setup);
2715 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
2716 			s3c2440_early_console_setup);
2717 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2718 			s3c2440_early_console_setup);
2719 
2720 /* S5PV210, Exynos */
2721 static struct samsung_early_console_data s5pv210_early_console_data = {
2722 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2723 };
2724 
2725 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2726 					      const char *opt)
2727 {
2728 	device->port.private_data = &s5pv210_early_console_data;
2729 	return samsung_early_console_setup(device, opt);
2730 }
2731 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2732 			s5pv210_early_console_setup);
2733 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2734 			s5pv210_early_console_setup);
2735 #endif
2736 
2737 MODULE_ALIAS("platform:samsung-uart");
2738 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2739 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2740 MODULE_LICENSE("GPL v2");
2741