xref: /openbmc/linux/drivers/tty/serial/samsung_tty.c (revision de3a9980)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver core for Samsung SoC onboard UARTs.
4  *
5  * Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
6  *	http://armlinux.simtec.co.uk/
7  */
8 
9 /* Note on 2410 error handling
10  *
11  * The s3c2410 manual has a love/hate affair with the contents of the
12  * UERSTAT register in the UART blocks, and keeps marking some of the
13  * error bits as reserved. Having checked with the s3c2410x01,
14  * it copes with BREAKs properly, so I am happy to ignore the RESERVED
15  * feature from the latter versions of the manual.
16  *
17  * If it becomes aparrent that latter versions of the 2410 remove these
18  * bits, then action will have to be taken to differentiate the versions
19  * and change the policy on BREAK
20  *
21  * BJD, 04-Nov-2004
22  */
23 
24 #include <linux/dmaengine.h>
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/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 	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
331 	count = dma->tx_bytes_requested - state.residue;
332 	async_tx_ack(dma->tx_desc);
333 
334 	dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr,
335 				dma->tx_size, DMA_TO_DEVICE);
336 
337 	spin_lock_irqsave(&port->lock, flags);
338 
339 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
340 	port->icount.tx += count;
341 	ourport->tx_in_progress = 0;
342 
343 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
344 		uart_write_wakeup(port);
345 
346 	s3c24xx_serial_start_next_tx(ourport);
347 	spin_unlock_irqrestore(&port->lock, flags);
348 }
349 
350 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
351 {
352 	struct uart_port *port = &ourport->port;
353 	u32 ucon;
354 
355 	/* Mask Tx interrupt */
356 	if (s3c24xx_serial_has_interrupt_mask(port))
357 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
358 	else
359 		disable_irq_nosync(ourport->tx_irq);
360 
361 	/* Enable tx dma mode */
362 	ucon = rd_regl(port, S3C2410_UCON);
363 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
364 	ucon |= (dma_get_cache_alignment() >= 16) ?
365 		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
366 	ucon |= S3C64XX_UCON_TXMODE_DMA;
367 	wr_regl(port,  S3C2410_UCON, ucon);
368 
369 	ourport->tx_mode = S3C24XX_TX_DMA;
370 }
371 
372 static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
373 {
374 	struct uart_port *port = &ourport->port;
375 	u32 ucon, ufcon;
376 
377 	/* Set ufcon txtrig */
378 	ourport->tx_in_progress = S3C24XX_TX_PIO;
379 	ufcon = rd_regl(port, S3C2410_UFCON);
380 	wr_regl(port,  S3C2410_UFCON, ufcon);
381 
382 	/* Enable tx pio mode */
383 	ucon = rd_regl(port, S3C2410_UCON);
384 	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
385 	ucon |= S3C64XX_UCON_TXMODE_CPU;
386 	wr_regl(port,  S3C2410_UCON, ucon);
387 
388 	/* Unmask Tx interrupt */
389 	if (s3c24xx_serial_has_interrupt_mask(port))
390 		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
391 				  S3C64XX_UINTM);
392 	else
393 		enable_irq(ourport->tx_irq);
394 
395 	ourport->tx_mode = S3C24XX_TX_PIO;
396 }
397 
398 static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
399 {
400 	if (ourport->tx_mode != S3C24XX_TX_PIO)
401 		enable_tx_pio(ourport);
402 }
403 
404 static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
405 				      unsigned int count)
406 {
407 	struct uart_port *port = &ourport->port;
408 	struct circ_buf *xmit = &port->state->xmit;
409 	struct s3c24xx_uart_dma *dma = ourport->dma;
410 
411 	if (ourport->tx_mode != S3C24XX_TX_DMA)
412 		enable_tx_dma(ourport);
413 
414 	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
415 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
416 
417 	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
418 				dma->tx_size, DMA_TO_DEVICE);
419 
420 	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
421 				dma->tx_transfer_addr, dma->tx_size,
422 				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
423 	if (!dma->tx_desc) {
424 		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
425 		return -EIO;
426 	}
427 
428 	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
429 	dma->tx_desc->callback_param = ourport;
430 	dma->tx_bytes_requested = dma->tx_size;
431 
432 	ourport->tx_in_progress = S3C24XX_TX_DMA;
433 	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
434 	dma_async_issue_pending(dma->tx_chan);
435 	return 0;
436 }
437 
438 static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
439 {
440 	struct uart_port *port = &ourport->port;
441 	struct circ_buf *xmit = &port->state->xmit;
442 	unsigned long count;
443 
444 	/* Get data size up to the end of buffer */
445 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
446 
447 	if (!count) {
448 		s3c24xx_serial_stop_tx(port);
449 		return;
450 	}
451 
452 	if (!ourport->dma || !ourport->dma->tx_chan ||
453 	    count < ourport->min_dma_size ||
454 	    xmit->tail & (dma_get_cache_alignment() - 1))
455 		s3c24xx_serial_start_tx_pio(ourport);
456 	else
457 		s3c24xx_serial_start_tx_dma(ourport, count);
458 }
459 
460 static void s3c24xx_serial_start_tx(struct uart_port *port)
461 {
462 	struct s3c24xx_uart_port *ourport = to_ourport(port);
463 	struct circ_buf *xmit = &port->state->xmit;
464 
465 	if (!ourport->tx_enabled) {
466 		if (port->flags & UPF_CONS_FLOW)
467 			s3c24xx_serial_rx_disable(port);
468 
469 		ourport->tx_enabled = 1;
470 		if (!ourport->dma || !ourport->dma->tx_chan)
471 			s3c24xx_serial_start_tx_pio(ourport);
472 	}
473 
474 	if (ourport->dma && ourport->dma->tx_chan) {
475 		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
476 			s3c24xx_serial_start_next_tx(ourport);
477 	}
478 }
479 
480 static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
481 		struct tty_port *tty, int count)
482 {
483 	struct s3c24xx_uart_dma *dma = ourport->dma;
484 	int copied;
485 
486 	if (!count)
487 		return;
488 
489 	dma_sync_single_for_cpu(ourport->port.dev, dma->rx_addr,
490 				dma->rx_size, DMA_FROM_DEVICE);
491 
492 	ourport->port.icount.rx += count;
493 	if (!tty) {
494 		dev_err(ourport->port.dev, "No tty port\n");
495 		return;
496 	}
497 	copied = tty_insert_flip_string(tty,
498 			((unsigned char *)(ourport->dma->rx_buf)), count);
499 	if (copied != count) {
500 		WARN_ON(1);
501 		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
502 	}
503 }
504 
505 static void s3c24xx_serial_stop_rx(struct uart_port *port)
506 {
507 	struct s3c24xx_uart_port *ourport = to_ourport(port);
508 	struct s3c24xx_uart_dma *dma = ourport->dma;
509 	struct tty_port *t = &port->state->port;
510 	struct dma_tx_state state;
511 	enum dma_status dma_status;
512 	unsigned int received;
513 
514 	if (ourport->rx_enabled) {
515 		dev_dbg(port->dev, "stopping rx\n");
516 		if (s3c24xx_serial_has_interrupt_mask(port))
517 			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
518 					S3C64XX_UINTM);
519 		else
520 			disable_irq_nosync(ourport->rx_irq);
521 		ourport->rx_enabled = 0;
522 	}
523 	if (dma && dma->rx_chan) {
524 		dmaengine_pause(dma->tx_chan);
525 		dma_status = dmaengine_tx_status(dma->rx_chan,
526 				dma->rx_cookie, &state);
527 		if (dma_status == DMA_IN_PROGRESS ||
528 			dma_status == DMA_PAUSED) {
529 			received = dma->rx_bytes_requested - state.residue;
530 			dmaengine_terminate_all(dma->rx_chan);
531 			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
532 		}
533 	}
534 }
535 
536 static inline struct s3c24xx_uart_info
537 	*s3c24xx_port_to_info(struct uart_port *port)
538 {
539 	return to_ourport(port)->info;
540 }
541 
542 static inline struct s3c2410_uartcfg
543 	*s3c24xx_port_to_cfg(struct uart_port *port)
544 {
545 	struct s3c24xx_uart_port *ourport;
546 
547 	if (port->dev == NULL)
548 		return NULL;
549 
550 	ourport = container_of(port, struct s3c24xx_uart_port, port);
551 	return ourport->cfg;
552 }
553 
554 static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
555 				     unsigned long ufstat)
556 {
557 	struct s3c24xx_uart_info *info = ourport->info;
558 
559 	if (ufstat & info->rx_fifofull)
560 		return ourport->port.fifosize;
561 
562 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
563 }
564 
565 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
566 static void s3c24xx_serial_rx_dma_complete(void *args)
567 {
568 	struct s3c24xx_uart_port *ourport = args;
569 	struct uart_port *port = &ourport->port;
570 
571 	struct s3c24xx_uart_dma *dma = ourport->dma;
572 	struct tty_port *t = &port->state->port;
573 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
574 
575 	struct dma_tx_state state;
576 	unsigned long flags;
577 	int received;
578 
579 	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
580 	received  = dma->rx_bytes_requested - state.residue;
581 	async_tx_ack(dma->rx_desc);
582 
583 	spin_lock_irqsave(&port->lock, flags);
584 
585 	if (received)
586 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
587 
588 	if (tty) {
589 		tty_flip_buffer_push(t);
590 		tty_kref_put(tty);
591 	}
592 
593 	s3c64xx_start_rx_dma(ourport);
594 
595 	spin_unlock_irqrestore(&port->lock, flags);
596 }
597 
598 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
599 {
600 	struct s3c24xx_uart_dma *dma = ourport->dma;
601 
602 	dma_sync_single_for_device(ourport->port.dev, dma->rx_addr,
603 				dma->rx_size, DMA_FROM_DEVICE);
604 
605 	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
606 				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
607 				DMA_PREP_INTERRUPT);
608 	if (!dma->rx_desc) {
609 		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
610 		return;
611 	}
612 
613 	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
614 	dma->rx_desc->callback_param = ourport;
615 	dma->rx_bytes_requested = dma->rx_size;
616 
617 	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
618 	dma_async_issue_pending(dma->rx_chan);
619 }
620 
621 /* ? - where has parity gone?? */
622 #define S3C2410_UERSTAT_PARITY (0x1000)
623 
624 static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
625 {
626 	struct uart_port *port = &ourport->port;
627 	unsigned int ucon;
628 
629 	/* set Rx mode to DMA mode */
630 	ucon = rd_regl(port, S3C2410_UCON);
631 	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
632 			S3C64XX_UCON_TIMEOUT_MASK |
633 			S3C64XX_UCON_EMPTYINT_EN |
634 			S3C64XX_UCON_DMASUS_EN |
635 			S3C64XX_UCON_TIMEOUT_EN |
636 			S3C64XX_UCON_RXMODE_MASK);
637 	ucon |= S3C64XX_UCON_RXBURST_16 |
638 			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
639 			S3C64XX_UCON_EMPTYINT_EN |
640 			S3C64XX_UCON_TIMEOUT_EN |
641 			S3C64XX_UCON_RXMODE_DMA;
642 	wr_regl(port, S3C2410_UCON, ucon);
643 
644 	ourport->rx_mode = S3C24XX_RX_DMA;
645 }
646 
647 static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
648 {
649 	struct uart_port *port = &ourport->port;
650 	unsigned int ucon;
651 
652 	/* set Rx mode to DMA mode */
653 	ucon = rd_regl(port, S3C2410_UCON);
654 	ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
655 			S3C64XX_UCON_EMPTYINT_EN |
656 			S3C64XX_UCON_DMASUS_EN |
657 			S3C64XX_UCON_TIMEOUT_EN |
658 			S3C64XX_UCON_RXMODE_MASK);
659 	ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
660 			S3C64XX_UCON_TIMEOUT_EN |
661 			S3C64XX_UCON_RXMODE_CPU;
662 	wr_regl(port, S3C2410_UCON, ucon);
663 
664 	ourport->rx_mode = S3C24XX_RX_PIO;
665 }
666 
667 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport);
668 
669 static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
670 {
671 	unsigned int utrstat, received;
672 	struct s3c24xx_uart_port *ourport = dev_id;
673 	struct uart_port *port = &ourport->port;
674 	struct s3c24xx_uart_dma *dma = ourport->dma;
675 	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
676 	struct tty_port *t = &port->state->port;
677 	unsigned long flags;
678 	struct dma_tx_state state;
679 
680 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
681 	rd_regl(port, S3C2410_UFSTAT);
682 
683 	spin_lock_irqsave(&port->lock, flags);
684 
685 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
686 		s3c64xx_start_rx_dma(ourport);
687 		if (ourport->rx_mode == S3C24XX_RX_PIO)
688 			enable_rx_dma(ourport);
689 		goto finish;
690 	}
691 
692 	if (ourport->rx_mode == S3C24XX_RX_DMA) {
693 		dmaengine_pause(dma->rx_chan);
694 		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
695 		dmaengine_terminate_all(dma->rx_chan);
696 		received = dma->rx_bytes_requested - state.residue;
697 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
698 
699 		enable_rx_pio(ourport);
700 	}
701 
702 	s3c24xx_serial_rx_drain_fifo(ourport);
703 
704 	if (tty) {
705 		tty_flip_buffer_push(t);
706 		tty_kref_put(tty);
707 	}
708 
709 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
710 
711 finish:
712 	spin_unlock_irqrestore(&port->lock, flags);
713 
714 	return IRQ_HANDLED;
715 }
716 
717 static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
718 {
719 	struct uart_port *port = &ourport->port;
720 	unsigned int ufcon, ch, flag, ufstat, uerstat;
721 	unsigned int fifocnt = 0;
722 	int max_count = port->fifosize;
723 
724 	while (max_count-- > 0) {
725 		/*
726 		 * Receive all characters known to be in FIFO
727 		 * before reading FIFO level again
728 		 */
729 		if (fifocnt == 0) {
730 			ufstat = rd_regl(port, S3C2410_UFSTAT);
731 			fifocnt = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
732 			if (fifocnt == 0)
733 				break;
734 		}
735 		fifocnt--;
736 
737 		uerstat = rd_regl(port, S3C2410_UERSTAT);
738 		ch = rd_reg(port, S3C2410_URXH);
739 
740 		if (port->flags & UPF_CONS_FLOW) {
741 			int txe = s3c24xx_serial_txempty_nofifo(port);
742 
743 			if (ourport->rx_enabled) {
744 				if (!txe) {
745 					ourport->rx_enabled = 0;
746 					continue;
747 				}
748 			} else {
749 				if (txe) {
750 					ufcon = rd_regl(port, S3C2410_UFCON);
751 					ufcon |= S3C2410_UFCON_RESETRX;
752 					wr_regl(port, S3C2410_UFCON, ufcon);
753 					ourport->rx_enabled = 1;
754 					return;
755 				}
756 				continue;
757 			}
758 		}
759 
760 		/* insert the character into the buffer */
761 
762 		flag = TTY_NORMAL;
763 		port->icount.rx++;
764 
765 		if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
766 			dev_dbg(port->dev,
767 				"rxerr: port ch=0x%02x, rxs=0x%08x\n",
768 				ch, uerstat);
769 
770 			/* check for break */
771 			if (uerstat & S3C2410_UERSTAT_BREAK) {
772 				dev_dbg(port->dev, "break!\n");
773 				port->icount.brk++;
774 				if (uart_handle_break(port))
775 					continue; /* Ignore character */
776 			}
777 
778 			if (uerstat & S3C2410_UERSTAT_FRAME)
779 				port->icount.frame++;
780 			if (uerstat & S3C2410_UERSTAT_OVERRUN)
781 				port->icount.overrun++;
782 
783 			uerstat &= port->read_status_mask;
784 
785 			if (uerstat & S3C2410_UERSTAT_BREAK)
786 				flag = TTY_BREAK;
787 			else if (uerstat & S3C2410_UERSTAT_PARITY)
788 				flag = TTY_PARITY;
789 			else if (uerstat & (S3C2410_UERSTAT_FRAME |
790 					    S3C2410_UERSTAT_OVERRUN))
791 				flag = TTY_FRAME;
792 		}
793 
794 		if (uart_handle_sysrq_char(port, ch))
795 			continue; /* Ignore character */
796 
797 		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
798 				 ch, flag);
799 	}
800 
801 	tty_flip_buffer_push(&port->state->port);
802 }
803 
804 static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
805 {
806 	struct s3c24xx_uart_port *ourport = dev_id;
807 	struct uart_port *port = &ourport->port;
808 	unsigned long flags;
809 
810 	spin_lock_irqsave(&port->lock, flags);
811 	s3c24xx_serial_rx_drain_fifo(ourport);
812 	spin_unlock_irqrestore(&port->lock, flags);
813 
814 	return IRQ_HANDLED;
815 }
816 
817 static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id)
818 {
819 	struct s3c24xx_uart_port *ourport = dev_id;
820 
821 	if (ourport->dma && ourport->dma->rx_chan)
822 		return s3c24xx_serial_rx_chars_dma(dev_id);
823 	return s3c24xx_serial_rx_chars_pio(dev_id);
824 }
825 
826 static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
827 {
828 	struct s3c24xx_uart_port *ourport = id;
829 	struct uart_port *port = &ourport->port;
830 	struct circ_buf *xmit = &port->state->xmit;
831 	unsigned long flags;
832 	int count, dma_count = 0;
833 
834 	spin_lock_irqsave(&port->lock, flags);
835 
836 	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
837 
838 	if (ourport->dma && ourport->dma->tx_chan &&
839 	    count >= ourport->min_dma_size) {
840 		int align = dma_get_cache_alignment() -
841 			(xmit->tail & (dma_get_cache_alignment() - 1));
842 		if (count - align >= ourport->min_dma_size) {
843 			dma_count = count - align;
844 			count = align;
845 		}
846 	}
847 
848 	if (port->x_char) {
849 		wr_reg(port, S3C2410_UTXH, port->x_char);
850 		port->icount.tx++;
851 		port->x_char = 0;
852 		goto out;
853 	}
854 
855 	/* if there isn't anything more to transmit, or the uart is now
856 	 * stopped, disable the uart and exit
857 	 */
858 
859 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
860 		s3c24xx_serial_stop_tx(port);
861 		goto out;
862 	}
863 
864 	/* try and drain the buffer... */
865 
866 	if (count > port->fifosize) {
867 		count = port->fifosize;
868 		dma_count = 0;
869 	}
870 
871 	while (!uart_circ_empty(xmit) && count > 0) {
872 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
873 			break;
874 
875 		wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
876 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
877 		port->icount.tx++;
878 		count--;
879 	}
880 
881 	if (!count && dma_count) {
882 		s3c24xx_serial_start_tx_dma(ourport, dma_count);
883 		goto out;
884 	}
885 
886 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
887 		spin_unlock(&port->lock);
888 		uart_write_wakeup(port);
889 		spin_lock(&port->lock);
890 	}
891 
892 	if (uart_circ_empty(xmit))
893 		s3c24xx_serial_stop_tx(port);
894 
895 out:
896 	spin_unlock_irqrestore(&port->lock, flags);
897 	return IRQ_HANDLED;
898 }
899 
900 /* interrupt handler for s3c64xx and later SoC's.*/
901 static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
902 {
903 	struct s3c24xx_uart_port *ourport = id;
904 	struct uart_port *port = &ourport->port;
905 	unsigned int pend = rd_regl(port, S3C64XX_UINTP);
906 	irqreturn_t ret = IRQ_HANDLED;
907 
908 	if (pend & S3C64XX_UINTM_RXD_MSK) {
909 		ret = s3c24xx_serial_rx_chars(irq, id);
910 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
911 	}
912 	if (pend & S3C64XX_UINTM_TXD_MSK) {
913 		ret = s3c24xx_serial_tx_chars(irq, id);
914 		wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
915 	}
916 	return ret;
917 }
918 
919 static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
920 {
921 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
922 	unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
923 	unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
924 
925 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
926 		if ((ufstat & info->tx_fifomask) != 0 ||
927 		    (ufstat & info->tx_fifofull))
928 			return 0;
929 
930 		return 1;
931 	}
932 
933 	return s3c24xx_serial_txempty_nofifo(port);
934 }
935 
936 /* no modem control lines */
937 static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
938 {
939 	unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
940 
941 	if (umstat & S3C2410_UMSTAT_CTS)
942 		return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
943 	else
944 		return TIOCM_CAR | TIOCM_DSR;
945 }
946 
947 static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
948 {
949 	unsigned int umcon = rd_regl(port, S3C2410_UMCON);
950 
951 	if (mctrl & TIOCM_RTS)
952 		umcon |= S3C2410_UMCOM_RTS_LOW;
953 	else
954 		umcon &= ~S3C2410_UMCOM_RTS_LOW;
955 
956 	wr_regl(port, S3C2410_UMCON, umcon);
957 }
958 
959 static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
960 {
961 	unsigned long flags;
962 	unsigned int ucon;
963 
964 	spin_lock_irqsave(&port->lock, flags);
965 
966 	ucon = rd_regl(port, S3C2410_UCON);
967 
968 	if (break_state)
969 		ucon |= S3C2410_UCON_SBREAK;
970 	else
971 		ucon &= ~S3C2410_UCON_SBREAK;
972 
973 	wr_regl(port, S3C2410_UCON, ucon);
974 
975 	spin_unlock_irqrestore(&port->lock, flags);
976 }
977 
978 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
979 {
980 	struct s3c24xx_uart_dma	*dma = p->dma;
981 	struct dma_slave_caps dma_caps;
982 	const char *reason = NULL;
983 	int ret;
984 
985 	/* Default slave configuration parameters */
986 	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
987 	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
988 	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
989 	dma->rx_conf.src_maxburst	= 1;
990 
991 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
992 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
993 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
994 	dma->tx_conf.dst_maxburst	= 1;
995 
996 	dma->rx_chan = dma_request_chan(p->port.dev, "rx");
997 
998 	if (IS_ERR(dma->rx_chan)) {
999 		reason = "DMA RX channel request failed";
1000 		ret = PTR_ERR(dma->rx_chan);
1001 		goto err_warn;
1002 	}
1003 
1004 	ret = dma_get_slave_caps(dma->rx_chan, &dma_caps);
1005 	if (ret < 0 ||
1006 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1007 		reason = "insufficient DMA RX engine capabilities";
1008 		ret = -EOPNOTSUPP;
1009 		goto err_release_rx;
1010 	}
1011 
1012 	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
1013 
1014 	dma->tx_chan = dma_request_chan(p->port.dev, "tx");
1015 	if (IS_ERR(dma->tx_chan)) {
1016 		reason = "DMA TX channel request failed";
1017 		ret = PTR_ERR(dma->tx_chan);
1018 		goto err_release_rx;
1019 	}
1020 
1021 	ret = dma_get_slave_caps(dma->tx_chan, &dma_caps);
1022 	if (ret < 0 ||
1023 	    dma_caps.residue_granularity < DMA_RESIDUE_GRANULARITY_BURST) {
1024 		reason = "insufficient DMA TX engine capabilities";
1025 		ret = -EOPNOTSUPP;
1026 		goto err_release_tx;
1027 	}
1028 
1029 	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
1030 
1031 	/* RX buffer */
1032 	dma->rx_size = PAGE_SIZE;
1033 
1034 	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
1035 	if (!dma->rx_buf) {
1036 		ret = -ENOMEM;
1037 		goto err_release_tx;
1038 	}
1039 
1040 	dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf,
1041 				dma->rx_size, DMA_FROM_DEVICE);
1042 	if (dma_mapping_error(p->port.dev, dma->rx_addr)) {
1043 		reason = "DMA mapping error for RX buffer";
1044 		ret = -EIO;
1045 		goto err_free_rx;
1046 	}
1047 
1048 	/* TX buffer */
1049 	dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf,
1050 				UART_XMIT_SIZE, DMA_TO_DEVICE);
1051 	if (dma_mapping_error(p->port.dev, dma->tx_addr)) {
1052 		reason = "DMA mapping error for TX buffer";
1053 		ret = -EIO;
1054 		goto err_unmap_rx;
1055 	}
1056 
1057 	return 0;
1058 
1059 err_unmap_rx:
1060 	dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size,
1061 			 DMA_FROM_DEVICE);
1062 err_free_rx:
1063 	kfree(dma->rx_buf);
1064 err_release_tx:
1065 	dma_release_channel(dma->tx_chan);
1066 err_release_rx:
1067 	dma_release_channel(dma->rx_chan);
1068 err_warn:
1069 	if (reason)
1070 		dev_warn(p->port.dev, "%s, DMA will not be used\n", reason);
1071 	return ret;
1072 }
1073 
1074 static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
1075 {
1076 	struct s3c24xx_uart_dma	*dma = p->dma;
1077 
1078 	if (dma->rx_chan) {
1079 		dmaengine_terminate_all(dma->rx_chan);
1080 		dma_unmap_single(p->port.dev, dma->rx_addr,
1081 				dma->rx_size, DMA_FROM_DEVICE);
1082 		kfree(dma->rx_buf);
1083 		dma_release_channel(dma->rx_chan);
1084 		dma->rx_chan = NULL;
1085 	}
1086 
1087 	if (dma->tx_chan) {
1088 		dmaengine_terminate_all(dma->tx_chan);
1089 		dma_unmap_single(p->port.dev, dma->tx_addr,
1090 				UART_XMIT_SIZE, DMA_TO_DEVICE);
1091 		dma_release_channel(dma->tx_chan);
1092 		dma->tx_chan = NULL;
1093 	}
1094 }
1095 
1096 static void s3c24xx_serial_shutdown(struct uart_port *port)
1097 {
1098 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1099 
1100 	if (ourport->tx_claimed) {
1101 		if (!s3c24xx_serial_has_interrupt_mask(port))
1102 			free_irq(ourport->tx_irq, ourport);
1103 		ourport->tx_enabled = 0;
1104 		ourport->tx_claimed = 0;
1105 		ourport->tx_mode = 0;
1106 	}
1107 
1108 	if (ourport->rx_claimed) {
1109 		if (!s3c24xx_serial_has_interrupt_mask(port))
1110 			free_irq(ourport->rx_irq, ourport);
1111 		ourport->rx_claimed = 0;
1112 		ourport->rx_enabled = 0;
1113 	}
1114 
1115 	/* Clear pending interrupts and mask all interrupts */
1116 	if (s3c24xx_serial_has_interrupt_mask(port)) {
1117 		free_irq(port->irq, ourport);
1118 
1119 		wr_regl(port, S3C64XX_UINTP, 0xf);
1120 		wr_regl(port, S3C64XX_UINTM, 0xf);
1121 	}
1122 
1123 	if (ourport->dma)
1124 		s3c24xx_serial_release_dma(ourport);
1125 
1126 	ourport->tx_in_progress = 0;
1127 }
1128 
1129 static int s3c24xx_serial_startup(struct uart_port *port)
1130 {
1131 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1132 	int ret;
1133 
1134 	ourport->rx_enabled = 1;
1135 
1136 	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
1137 			  s3c24xx_serial_portname(port), ourport);
1138 
1139 	if (ret != 0) {
1140 		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
1141 		return ret;
1142 	}
1143 
1144 	ourport->rx_claimed = 1;
1145 
1146 	dev_dbg(port->dev, "requesting tx irq...\n");
1147 
1148 	ourport->tx_enabled = 1;
1149 
1150 	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
1151 			  s3c24xx_serial_portname(port), ourport);
1152 
1153 	if (ret) {
1154 		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
1155 		goto err;
1156 	}
1157 
1158 	ourport->tx_claimed = 1;
1159 
1160 	/* the port reset code should have done the correct
1161 	 * register setup for the port controls
1162 	 */
1163 
1164 	return ret;
1165 
1166 err:
1167 	s3c24xx_serial_shutdown(port);
1168 	return ret;
1169 }
1170 
1171 static int s3c64xx_serial_startup(struct uart_port *port)
1172 {
1173 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1174 	unsigned long flags;
1175 	unsigned int ufcon;
1176 	int ret;
1177 
1178 	wr_regl(port, S3C64XX_UINTM, 0xf);
1179 	if (ourport->dma) {
1180 		ret = s3c24xx_serial_request_dma(ourport);
1181 		if (ret < 0) {
1182 			devm_kfree(port->dev, ourport->dma);
1183 			ourport->dma = NULL;
1184 		}
1185 	}
1186 
1187 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
1188 			  s3c24xx_serial_portname(port), ourport);
1189 	if (ret) {
1190 		dev_err(port->dev, "cannot get irq %d\n", port->irq);
1191 		return ret;
1192 	}
1193 
1194 	/* For compatibility with s3c24xx Soc's */
1195 	ourport->rx_enabled = 1;
1196 	ourport->rx_claimed = 1;
1197 	ourport->tx_enabled = 0;
1198 	ourport->tx_claimed = 1;
1199 
1200 	spin_lock_irqsave(&port->lock, flags);
1201 
1202 	ufcon = rd_regl(port, S3C2410_UFCON);
1203 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
1204 	if (!uart_console(port))
1205 		ufcon |= S3C2410_UFCON_RESETTX;
1206 	wr_regl(port, S3C2410_UFCON, ufcon);
1207 
1208 	enable_rx_pio(ourport);
1209 
1210 	spin_unlock_irqrestore(&port->lock, flags);
1211 
1212 	/* Enable Rx Interrupt */
1213 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
1214 
1215 	return ret;
1216 }
1217 
1218 /* power power management control */
1219 
1220 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
1221 			      unsigned int old)
1222 {
1223 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1224 	int timeout = 10000;
1225 
1226 	ourport->pm_level = level;
1227 
1228 	switch (level) {
1229 	case 3:
1230 		while (--timeout && !s3c24xx_serial_txempty_nofifo(port))
1231 			udelay(100);
1232 
1233 		if (!IS_ERR(ourport->baudclk))
1234 			clk_disable_unprepare(ourport->baudclk);
1235 
1236 		clk_disable_unprepare(ourport->clk);
1237 		break;
1238 
1239 	case 0:
1240 		clk_prepare_enable(ourport->clk);
1241 
1242 		if (!IS_ERR(ourport->baudclk))
1243 			clk_prepare_enable(ourport->baudclk);
1244 
1245 		break;
1246 	default:
1247 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
1248 	}
1249 }
1250 
1251 /* baud rate calculation
1252  *
1253  * The UARTs on the S3C2410/S3C2440 can take their clocks from a number
1254  * of different sources, including the peripheral clock ("pclk") and an
1255  * external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
1256  * with a programmable extra divisor.
1257  *
1258  * The following code goes through the clock sources, and calculates the
1259  * baud clocks (and the resultant actual baud rates) and then tries to
1260  * pick the closest one and select that.
1261  *
1262  */
1263 
1264 #define MAX_CLK_NAME_LENGTH 15
1265 
1266 static inline int s3c24xx_serial_getsource(struct uart_port *port)
1267 {
1268 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1269 	unsigned int ucon;
1270 
1271 	if (info->num_clks == 1)
1272 		return 0;
1273 
1274 	ucon = rd_regl(port, S3C2410_UCON);
1275 	ucon &= info->clksel_mask;
1276 	return ucon >> info->clksel_shift;
1277 }
1278 
1279 static void s3c24xx_serial_setsource(struct uart_port *port,
1280 			unsigned int clk_sel)
1281 {
1282 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1283 	unsigned int ucon;
1284 
1285 	if (info->num_clks == 1)
1286 		return;
1287 
1288 	ucon = rd_regl(port, S3C2410_UCON);
1289 	if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel)
1290 		return;
1291 
1292 	ucon &= ~info->clksel_mask;
1293 	ucon |= clk_sel << info->clksel_shift;
1294 	wr_regl(port, S3C2410_UCON, ucon);
1295 }
1296 
1297 static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
1298 			unsigned int req_baud, struct clk **best_clk,
1299 			unsigned int *clk_num)
1300 {
1301 	struct s3c24xx_uart_info *info = ourport->info;
1302 	struct clk *clk;
1303 	unsigned long rate;
1304 	unsigned int cnt, baud, quot, best_quot = 0;
1305 	char clkname[MAX_CLK_NAME_LENGTH];
1306 	int calc_deviation, deviation = (1 << 30) - 1;
1307 
1308 	for (cnt = 0; cnt < info->num_clks; cnt++) {
1309 		/* Keep selected clock if provided */
1310 		if (ourport->cfg->clk_sel &&
1311 			!(ourport->cfg->clk_sel & (1 << cnt)))
1312 			continue;
1313 
1314 		sprintf(clkname, "clk_uart_baud%d", cnt);
1315 		clk = clk_get(ourport->port.dev, clkname);
1316 		if (IS_ERR(clk))
1317 			continue;
1318 
1319 		rate = clk_get_rate(clk);
1320 		if (!rate)
1321 			continue;
1322 
1323 		if (ourport->info->has_divslot) {
1324 			unsigned long div = rate / req_baud;
1325 
1326 			/* The UDIVSLOT register on the newer UARTs allows us to
1327 			 * get a divisor adjustment of 1/16th on the baud clock.
1328 			 *
1329 			 * We don't keep the UDIVSLOT value (the 16ths we
1330 			 * calculated by not multiplying the baud by 16) as it
1331 			 * is easy enough to recalculate.
1332 			 */
1333 
1334 			quot = div / 16;
1335 			baud = rate / div;
1336 		} else {
1337 			quot = (rate + (8 * req_baud)) / (16 * req_baud);
1338 			baud = rate / (quot * 16);
1339 		}
1340 		quot--;
1341 
1342 		calc_deviation = req_baud - baud;
1343 		if (calc_deviation < 0)
1344 			calc_deviation = -calc_deviation;
1345 
1346 		if (calc_deviation < deviation) {
1347 			*best_clk = clk;
1348 			best_quot = quot;
1349 			*clk_num = cnt;
1350 			deviation = calc_deviation;
1351 		}
1352 	}
1353 
1354 	return best_quot;
1355 }
1356 
1357 /* udivslot_table[]
1358  *
1359  * This table takes the fractional value of the baud divisor and gives
1360  * the recommended setting for the UDIVSLOT register.
1361  */
1362 static u16 udivslot_table[16] = {
1363 	[0] = 0x0000,
1364 	[1] = 0x0080,
1365 	[2] = 0x0808,
1366 	[3] = 0x0888,
1367 	[4] = 0x2222,
1368 	[5] = 0x4924,
1369 	[6] = 0x4A52,
1370 	[7] = 0x54AA,
1371 	[8] = 0x5555,
1372 	[9] = 0xD555,
1373 	[10] = 0xD5D5,
1374 	[11] = 0xDDD5,
1375 	[12] = 0xDDDD,
1376 	[13] = 0xDFDD,
1377 	[14] = 0xDFDF,
1378 	[15] = 0xFFDF,
1379 };
1380 
1381 static void s3c24xx_serial_set_termios(struct uart_port *port,
1382 				       struct ktermios *termios,
1383 				       struct ktermios *old)
1384 {
1385 	struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
1386 	struct s3c24xx_uart_port *ourport = to_ourport(port);
1387 	struct clk *clk = ERR_PTR(-EINVAL);
1388 	unsigned long flags;
1389 	unsigned int baud, quot, clk_sel = 0;
1390 	unsigned int ulcon;
1391 	unsigned int umcon;
1392 	unsigned int udivslot = 0;
1393 
1394 	/*
1395 	 * We don't support modem control lines.
1396 	 */
1397 	termios->c_cflag &= ~(HUPCL | CMSPAR);
1398 	termios->c_cflag |= CLOCAL;
1399 
1400 	/*
1401 	 * Ask the core to calculate the divisor for us.
1402 	 */
1403 
1404 	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
1405 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
1406 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
1407 		quot = port->custom_divisor;
1408 	if (IS_ERR(clk))
1409 		return;
1410 
1411 	/* check to see if we need  to change clock source */
1412 
1413 	if (ourport->baudclk != clk) {
1414 		clk_prepare_enable(clk);
1415 
1416 		s3c24xx_serial_setsource(port, clk_sel);
1417 
1418 		if (!IS_ERR(ourport->baudclk)) {
1419 			clk_disable_unprepare(ourport->baudclk);
1420 			ourport->baudclk = ERR_PTR(-EINVAL);
1421 		}
1422 
1423 		ourport->baudclk = clk;
1424 		ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
1425 	}
1426 
1427 	if (ourport->info->has_divslot) {
1428 		unsigned int div = ourport->baudclk_rate / baud;
1429 
1430 		if (cfg->has_fracval) {
1431 			udivslot = (div & 15);
1432 			dev_dbg(port->dev, "fracval = %04x\n", udivslot);
1433 		} else {
1434 			udivslot = udivslot_table[div & 15];
1435 			dev_dbg(port->dev, "udivslot = %04x (div %d)\n",
1436 				udivslot, div & 15);
1437 		}
1438 	}
1439 
1440 	switch (termios->c_cflag & CSIZE) {
1441 	case CS5:
1442 		dev_dbg(port->dev, "config: 5bits/char\n");
1443 		ulcon = S3C2410_LCON_CS5;
1444 		break;
1445 	case CS6:
1446 		dev_dbg(port->dev, "config: 6bits/char\n");
1447 		ulcon = S3C2410_LCON_CS6;
1448 		break;
1449 	case CS7:
1450 		dev_dbg(port->dev, "config: 7bits/char\n");
1451 		ulcon = S3C2410_LCON_CS7;
1452 		break;
1453 	case CS8:
1454 	default:
1455 		dev_dbg(port->dev, "config: 8bits/char\n");
1456 		ulcon = S3C2410_LCON_CS8;
1457 		break;
1458 	}
1459 
1460 	/* preserve original lcon IR settings */
1461 	ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
1462 
1463 	if (termios->c_cflag & CSTOPB)
1464 		ulcon |= S3C2410_LCON_STOPB;
1465 
1466 	if (termios->c_cflag & PARENB) {
1467 		if (termios->c_cflag & PARODD)
1468 			ulcon |= S3C2410_LCON_PODD;
1469 		else
1470 			ulcon |= S3C2410_LCON_PEVEN;
1471 	} else {
1472 		ulcon |= S3C2410_LCON_PNONE;
1473 	}
1474 
1475 	spin_lock_irqsave(&port->lock, flags);
1476 
1477 	dev_dbg(port->dev,
1478 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
1479 		ulcon, quot, udivslot);
1480 
1481 	wr_regl(port, S3C2410_ULCON, ulcon);
1482 	wr_regl(port, S3C2410_UBRDIV, quot);
1483 
1484 	port->status &= ~UPSTAT_AUTOCTS;
1485 
1486 	umcon = rd_regl(port, S3C2410_UMCON);
1487 	if (termios->c_cflag & CRTSCTS) {
1488 		umcon |= S3C2410_UMCOM_AFC;
1489 		/* Disable RTS when RX FIFO contains 63 bytes */
1490 		umcon &= ~S3C2412_UMCON_AFC_8;
1491 		port->status = UPSTAT_AUTOCTS;
1492 	} else {
1493 		umcon &= ~S3C2410_UMCOM_AFC;
1494 	}
1495 	wr_regl(port, S3C2410_UMCON, umcon);
1496 
1497 	if (ourport->info->has_divslot)
1498 		wr_regl(port, S3C2443_DIVSLOT, udivslot);
1499 
1500 	dev_dbg(port->dev,
1501 		"uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
1502 		rd_regl(port, S3C2410_ULCON),
1503 		rd_regl(port, S3C2410_UCON),
1504 		rd_regl(port, S3C2410_UFCON));
1505 
1506 	/*
1507 	 * Update the per-port timeout.
1508 	 */
1509 	uart_update_timeout(port, termios->c_cflag, baud);
1510 
1511 	/*
1512 	 * Which character status flags are we interested in?
1513 	 */
1514 	port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
1515 	if (termios->c_iflag & INPCK)
1516 		port->read_status_mask |= S3C2410_UERSTAT_FRAME |
1517 			S3C2410_UERSTAT_PARITY;
1518 	/*
1519 	 * Which character status flags should we ignore?
1520 	 */
1521 	port->ignore_status_mask = 0;
1522 	if (termios->c_iflag & IGNPAR)
1523 		port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
1524 	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
1525 		port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
1526 
1527 	/*
1528 	 * Ignore all characters if CREAD is not set.
1529 	 */
1530 	if ((termios->c_cflag & CREAD) == 0)
1531 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
1532 
1533 	spin_unlock_irqrestore(&port->lock, flags);
1534 }
1535 
1536 static const char *s3c24xx_serial_type(struct uart_port *port)
1537 {
1538 	switch (port->type) {
1539 	case PORT_S3C2410:
1540 		return "S3C2410";
1541 	case PORT_S3C2440:
1542 		return "S3C2440";
1543 	case PORT_S3C2412:
1544 		return "S3C2412";
1545 	case PORT_S3C6400:
1546 		return "S3C6400/10";
1547 	default:
1548 		return NULL;
1549 	}
1550 }
1551 
1552 #define MAP_SIZE (0x100)
1553 
1554 static void s3c24xx_serial_release_port(struct uart_port *port)
1555 {
1556 	release_mem_region(port->mapbase, MAP_SIZE);
1557 }
1558 
1559 static int s3c24xx_serial_request_port(struct uart_port *port)
1560 {
1561 	const char *name = s3c24xx_serial_portname(port);
1562 
1563 	return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
1564 }
1565 
1566 static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
1567 {
1568 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1569 
1570 	if (flags & UART_CONFIG_TYPE &&
1571 	    s3c24xx_serial_request_port(port) == 0)
1572 		port->type = info->type;
1573 }
1574 
1575 /*
1576  * verify the new serial_struct (for TIOCSSERIAL).
1577  */
1578 static int
1579 s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
1580 {
1581 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1582 
1583 	if (ser->type != PORT_UNKNOWN && ser->type != info->type)
1584 		return -EINVAL;
1585 
1586 	return 0;
1587 }
1588 
1589 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
1590 
1591 static struct console s3c24xx_serial_console;
1592 
1593 static int __init s3c24xx_serial_console_init(void)
1594 {
1595 	register_console(&s3c24xx_serial_console);
1596 	return 0;
1597 }
1598 console_initcall(s3c24xx_serial_console_init);
1599 
1600 #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
1601 #else
1602 #define S3C24XX_SERIAL_CONSOLE NULL
1603 #endif
1604 
1605 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1606 static int s3c24xx_serial_get_poll_char(struct uart_port *port);
1607 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
1608 			 unsigned char c);
1609 #endif
1610 
1611 static struct uart_ops s3c24xx_serial_ops = {
1612 	.pm		= s3c24xx_serial_pm,
1613 	.tx_empty	= s3c24xx_serial_tx_empty,
1614 	.get_mctrl	= s3c24xx_serial_get_mctrl,
1615 	.set_mctrl	= s3c24xx_serial_set_mctrl,
1616 	.stop_tx	= s3c24xx_serial_stop_tx,
1617 	.start_tx	= s3c24xx_serial_start_tx,
1618 	.stop_rx	= s3c24xx_serial_stop_rx,
1619 	.break_ctl	= s3c24xx_serial_break_ctl,
1620 	.startup	= s3c24xx_serial_startup,
1621 	.shutdown	= s3c24xx_serial_shutdown,
1622 	.set_termios	= s3c24xx_serial_set_termios,
1623 	.type		= s3c24xx_serial_type,
1624 	.release_port	= s3c24xx_serial_release_port,
1625 	.request_port	= s3c24xx_serial_request_port,
1626 	.config_port	= s3c24xx_serial_config_port,
1627 	.verify_port	= s3c24xx_serial_verify_port,
1628 #if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
1629 	.poll_get_char = s3c24xx_serial_get_poll_char,
1630 	.poll_put_char = s3c24xx_serial_put_poll_char,
1631 #endif
1632 };
1633 
1634 static struct uart_driver s3c24xx_uart_drv = {
1635 	.owner		= THIS_MODULE,
1636 	.driver_name	= "s3c2410_serial",
1637 	.nr		= CONFIG_SERIAL_SAMSUNG_UARTS,
1638 	.cons		= S3C24XX_SERIAL_CONSOLE,
1639 	.dev_name	= S3C24XX_SERIAL_NAME,
1640 	.major		= S3C24XX_SERIAL_MAJOR,
1641 	.minor		= S3C24XX_SERIAL_MINOR,
1642 };
1643 
1644 #define __PORT_LOCK_UNLOCKED(i) \
1645 	__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[i].port.lock)
1646 static struct s3c24xx_uart_port
1647 s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
1648 	[0] = {
1649 		.port = {
1650 			.lock		= __PORT_LOCK_UNLOCKED(0),
1651 			.iotype		= UPIO_MEM,
1652 			.uartclk	= 0,
1653 			.fifosize	= 16,
1654 			.ops		= &s3c24xx_serial_ops,
1655 			.flags		= UPF_BOOT_AUTOCONF,
1656 			.line		= 0,
1657 		}
1658 	},
1659 	[1] = {
1660 		.port = {
1661 			.lock		= __PORT_LOCK_UNLOCKED(1),
1662 			.iotype		= UPIO_MEM,
1663 			.uartclk	= 0,
1664 			.fifosize	= 16,
1665 			.ops		= &s3c24xx_serial_ops,
1666 			.flags		= UPF_BOOT_AUTOCONF,
1667 			.line		= 1,
1668 		}
1669 	},
1670 #if CONFIG_SERIAL_SAMSUNG_UARTS > 2
1671 	[2] = {
1672 		.port = {
1673 			.lock		= __PORT_LOCK_UNLOCKED(2),
1674 			.iotype		= UPIO_MEM,
1675 			.uartclk	= 0,
1676 			.fifosize	= 16,
1677 			.ops		= &s3c24xx_serial_ops,
1678 			.flags		= UPF_BOOT_AUTOCONF,
1679 			.line		= 2,
1680 		}
1681 	},
1682 #endif
1683 #if CONFIG_SERIAL_SAMSUNG_UARTS > 3
1684 	[3] = {
1685 		.port = {
1686 			.lock		= __PORT_LOCK_UNLOCKED(3),
1687 			.iotype		= UPIO_MEM,
1688 			.uartclk	= 0,
1689 			.fifosize	= 16,
1690 			.ops		= &s3c24xx_serial_ops,
1691 			.flags		= UPF_BOOT_AUTOCONF,
1692 			.line		= 3,
1693 		}
1694 	}
1695 #endif
1696 };
1697 #undef __PORT_LOCK_UNLOCKED
1698 
1699 /* s3c24xx_serial_resetport
1700  *
1701  * reset the fifos and other the settings.
1702  */
1703 
1704 static void s3c24xx_serial_resetport(struct uart_port *port,
1705 				   struct s3c2410_uartcfg *cfg)
1706 {
1707 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
1708 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
1709 	unsigned int ucon_mask;
1710 
1711 	ucon_mask = info->clksel_mask;
1712 	if (info->type == PORT_S3C2440)
1713 		ucon_mask |= S3C2440_UCON0_DIVMASK;
1714 
1715 	ucon &= ucon_mask;
1716 	wr_regl(port, S3C2410_UCON,  ucon | cfg->ucon);
1717 
1718 	/* reset both fifos */
1719 	wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
1720 	wr_regl(port, S3C2410_UFCON, cfg->ufcon);
1721 
1722 	/* some delay is required after fifo reset */
1723 	udelay(1);
1724 }
1725 
1726 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1727 
1728 static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
1729 					     unsigned long val, void *data)
1730 {
1731 	struct s3c24xx_uart_port *port;
1732 	struct uart_port *uport;
1733 
1734 	port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
1735 	uport = &port->port;
1736 
1737 	/* check to see if port is enabled */
1738 
1739 	if (port->pm_level != 0)
1740 		return 0;
1741 
1742 	/* try and work out if the baudrate is changing, we can detect
1743 	 * a change in rate, but we do not have support for detecting
1744 	 * a disturbance in the clock-rate over the change.
1745 	 */
1746 
1747 	if (IS_ERR(port->baudclk))
1748 		goto exit;
1749 
1750 	if (port->baudclk_rate == clk_get_rate(port->baudclk))
1751 		goto exit;
1752 
1753 	if (val == CPUFREQ_PRECHANGE) {
1754 		/* we should really shut the port down whilst the
1755 		 * frequency change is in progress.
1756 		 */
1757 
1758 	} else if (val == CPUFREQ_POSTCHANGE) {
1759 		struct ktermios *termios;
1760 		struct tty_struct *tty;
1761 
1762 		if (uport->state == NULL)
1763 			goto exit;
1764 
1765 		tty = uport->state->port.tty;
1766 
1767 		if (tty == NULL)
1768 			goto exit;
1769 
1770 		termios = &tty->termios;
1771 
1772 		if (termios == NULL) {
1773 			dev_warn(uport->dev, "%s: no termios?\n", __func__);
1774 			goto exit;
1775 		}
1776 
1777 		s3c24xx_serial_set_termios(uport, termios, NULL);
1778 	}
1779 
1780 exit:
1781 	return 0;
1782 }
1783 
1784 static inline int
1785 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1786 {
1787 	port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
1788 
1789 	return cpufreq_register_notifier(&port->freq_transition,
1790 					 CPUFREQ_TRANSITION_NOTIFIER);
1791 }
1792 
1793 static inline void
1794 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1795 {
1796 	cpufreq_unregister_notifier(&port->freq_transition,
1797 				    CPUFREQ_TRANSITION_NOTIFIER);
1798 }
1799 
1800 #else
1801 static inline int
1802 s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
1803 {
1804 	return 0;
1805 }
1806 
1807 static inline void
1808 s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
1809 {
1810 }
1811 #endif
1812 
1813 static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
1814 {
1815 	struct device *dev = ourport->port.dev;
1816 	struct s3c24xx_uart_info *info = ourport->info;
1817 	char clk_name[MAX_CLK_NAME_LENGTH];
1818 	unsigned int clk_sel;
1819 	struct clk *clk;
1820 	int clk_num;
1821 	int ret;
1822 
1823 	clk_sel = ourport->cfg->clk_sel ? : info->def_clk_sel;
1824 	for (clk_num = 0; clk_num < info->num_clks; clk_num++) {
1825 		if (!(clk_sel & (1 << clk_num)))
1826 			continue;
1827 
1828 		sprintf(clk_name, "clk_uart_baud%d", clk_num);
1829 		clk = clk_get(dev, clk_name);
1830 		if (IS_ERR(clk))
1831 			continue;
1832 
1833 		ret = clk_prepare_enable(clk);
1834 		if (ret) {
1835 			clk_put(clk);
1836 			continue;
1837 		}
1838 
1839 		ourport->baudclk = clk;
1840 		ourport->baudclk_rate = clk_get_rate(clk);
1841 		s3c24xx_serial_setsource(&ourport->port, clk_num);
1842 
1843 		return 0;
1844 	}
1845 
1846 	return -EINVAL;
1847 }
1848 
1849 /* s3c24xx_serial_init_port
1850  *
1851  * initialise a single serial port from the platform device given
1852  */
1853 
1854 static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
1855 				    struct platform_device *platdev)
1856 {
1857 	struct uart_port *port = &ourport->port;
1858 	struct s3c2410_uartcfg *cfg = ourport->cfg;
1859 	struct resource *res;
1860 	int ret;
1861 
1862 	if (platdev == NULL)
1863 		return -ENODEV;
1864 
1865 	if (port->mapbase != 0)
1866 		return -EINVAL;
1867 
1868 	/* setup info for port */
1869 	port->dev	= &platdev->dev;
1870 
1871 	/* Startup sequence is different for s3c64xx and higher SoC's */
1872 	if (s3c24xx_serial_has_interrupt_mask(port))
1873 		s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
1874 
1875 	port->uartclk = 1;
1876 
1877 	if (cfg->uart_flags & UPF_CONS_FLOW) {
1878 		dev_dbg(port->dev, "enabling flow control\n");
1879 		port->flags |= UPF_CONS_FLOW;
1880 	}
1881 
1882 	/* sort our the physical and virtual addresses for each UART */
1883 
1884 	res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
1885 	if (res == NULL) {
1886 		dev_err(port->dev, "failed to find memory resource for uart\n");
1887 		return -EINVAL;
1888 	}
1889 
1890 	dev_dbg(port->dev, "resource %pR)\n", res);
1891 
1892 	port->membase = devm_ioremap(port->dev, res->start, resource_size(res));
1893 	if (!port->membase) {
1894 		dev_err(port->dev, "failed to remap controller address\n");
1895 		return -EBUSY;
1896 	}
1897 
1898 	port->mapbase = res->start;
1899 	ret = platform_get_irq(platdev, 0);
1900 	if (ret < 0) {
1901 		port->irq = 0;
1902 	} else {
1903 		port->irq = ret;
1904 		ourport->rx_irq = ret;
1905 		ourport->tx_irq = ret + 1;
1906 	}
1907 
1908 	if (!s3c24xx_serial_has_interrupt_mask(port)) {
1909 		ret = platform_get_irq(platdev, 1);
1910 		if (ret > 0)
1911 			ourport->tx_irq = ret;
1912 	}
1913 	/*
1914 	 * DMA is currently supported only on DT platforms, if DMA properties
1915 	 * are specified.
1916 	 */
1917 	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
1918 						     "dmas", NULL)) {
1919 		ourport->dma = devm_kzalloc(port->dev,
1920 					    sizeof(*ourport->dma),
1921 					    GFP_KERNEL);
1922 		if (!ourport->dma) {
1923 			ret = -ENOMEM;
1924 			goto err;
1925 		}
1926 	}
1927 
1928 	ourport->clk	= clk_get(&platdev->dev, "uart");
1929 	if (IS_ERR(ourport->clk)) {
1930 		pr_err("%s: Controller clock not found\n",
1931 				dev_name(&platdev->dev));
1932 		ret = PTR_ERR(ourport->clk);
1933 		goto err;
1934 	}
1935 
1936 	ret = clk_prepare_enable(ourport->clk);
1937 	if (ret) {
1938 		pr_err("uart: clock failed to prepare+enable: %d\n", ret);
1939 		clk_put(ourport->clk);
1940 		goto err;
1941 	}
1942 
1943 	ret = s3c24xx_serial_enable_baudclk(ourport);
1944 	if (ret)
1945 		pr_warn("uart: failed to enable baudclk\n");
1946 
1947 	/* Keep all interrupts masked and cleared */
1948 	if (s3c24xx_serial_has_interrupt_mask(port)) {
1949 		wr_regl(port, S3C64XX_UINTM, 0xf);
1950 		wr_regl(port, S3C64XX_UINTP, 0xf);
1951 		wr_regl(port, S3C64XX_UINTSP, 0xf);
1952 	}
1953 
1954 	dev_dbg(port->dev, "port: map=%pa, mem=%p, irq=%d (%d,%d), clock=%u\n",
1955 		&port->mapbase, port->membase, port->irq,
1956 		ourport->rx_irq, ourport->tx_irq, port->uartclk);
1957 
1958 	/* reset the fifos (and setup the uart) */
1959 	s3c24xx_serial_resetport(port, cfg);
1960 
1961 	return 0;
1962 
1963 err:
1964 	port->mapbase = 0;
1965 	return ret;
1966 }
1967 
1968 /* Device driver serial port probe */
1969 
1970 #ifdef CONFIG_OF
1971 static const struct of_device_id s3c24xx_uart_dt_match[];
1972 #endif
1973 
1974 static int probe_index;
1975 
1976 static inline struct s3c24xx_serial_drv_data *
1977 s3c24xx_get_driver_data(struct platform_device *pdev)
1978 {
1979 #ifdef CONFIG_OF
1980 	if (pdev->dev.of_node) {
1981 		const struct of_device_id *match;
1982 
1983 		match = of_match_node(s3c24xx_uart_dt_match, pdev->dev.of_node);
1984 		return (struct s3c24xx_serial_drv_data *)match->data;
1985 	}
1986 #endif
1987 	return (struct s3c24xx_serial_drv_data *)
1988 			platform_get_device_id(pdev)->driver_data;
1989 }
1990 
1991 static int s3c24xx_serial_probe(struct platform_device *pdev)
1992 {
1993 	struct device_node *np = pdev->dev.of_node;
1994 	struct s3c24xx_uart_port *ourport;
1995 	int index = probe_index;
1996 	int ret, prop = 0;
1997 
1998 	if (np) {
1999 		ret = of_alias_get_id(np, "serial");
2000 		if (ret >= 0)
2001 			index = ret;
2002 	}
2003 
2004 	if (index >= ARRAY_SIZE(s3c24xx_serial_ports)) {
2005 		dev_err(&pdev->dev, "serial%d out of range\n", index);
2006 		return -EINVAL;
2007 	}
2008 	ourport = &s3c24xx_serial_ports[index];
2009 
2010 	ourport->drv_data = s3c24xx_get_driver_data(pdev);
2011 	if (!ourport->drv_data) {
2012 		dev_err(&pdev->dev, "could not find driver data\n");
2013 		return -ENODEV;
2014 	}
2015 
2016 	ourport->baudclk = ERR_PTR(-EINVAL);
2017 	ourport->info = ourport->drv_data->info;
2018 	ourport->cfg = (dev_get_platdata(&pdev->dev)) ?
2019 			dev_get_platdata(&pdev->dev) :
2020 			ourport->drv_data->def_cfg;
2021 
2022 	if (np) {
2023 		of_property_read_u32(np,
2024 			"samsung,uart-fifosize", &ourport->port.fifosize);
2025 
2026 		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
2027 			switch (prop) {
2028 			case 1:
2029 				ourport->port.iotype = UPIO_MEM;
2030 				break;
2031 			case 4:
2032 				ourport->port.iotype = UPIO_MEM32;
2033 				break;
2034 			default:
2035 				dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
2036 						prop);
2037 				ret = -EINVAL;
2038 				break;
2039 			}
2040 		}
2041 	}
2042 
2043 	if (ourport->drv_data->fifosize[index])
2044 		ourport->port.fifosize = ourport->drv_data->fifosize[index];
2045 	else if (ourport->info->fifosize)
2046 		ourport->port.fifosize = ourport->info->fifosize;
2047 	ourport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SAMSUNG_CONSOLE);
2048 
2049 	/*
2050 	 * DMA transfers must be aligned at least to cache line size,
2051 	 * so find minimal transfer size suitable for DMA mode
2052 	 */
2053 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
2054 				    dma_get_cache_alignment());
2055 
2056 	dev_dbg(&pdev->dev, "%s: initialising port %p...\n", __func__, ourport);
2057 
2058 	ret = s3c24xx_serial_init_port(ourport, pdev);
2059 	if (ret < 0)
2060 		return ret;
2061 
2062 	if (!s3c24xx_uart_drv.state) {
2063 		ret = uart_register_driver(&s3c24xx_uart_drv);
2064 		if (ret < 0) {
2065 			pr_err("Failed to register Samsung UART driver\n");
2066 			return ret;
2067 		}
2068 	}
2069 
2070 	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
2071 	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
2072 	platform_set_drvdata(pdev, &ourport->port);
2073 
2074 	/*
2075 	 * Deactivate the clock enabled in s3c24xx_serial_init_port here,
2076 	 * so that a potential re-enablement through the pm-callback overlaps
2077 	 * and keeps the clock enabled in this case.
2078 	 */
2079 	clk_disable_unprepare(ourport->clk);
2080 	if (!IS_ERR(ourport->baudclk))
2081 		clk_disable_unprepare(ourport->baudclk);
2082 
2083 	ret = s3c24xx_serial_cpufreq_register(ourport);
2084 	if (ret < 0)
2085 		dev_err(&pdev->dev, "failed to add cpufreq notifier\n");
2086 
2087 	probe_index++;
2088 
2089 	return 0;
2090 }
2091 
2092 static int s3c24xx_serial_remove(struct platform_device *dev)
2093 {
2094 	struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
2095 
2096 	if (port) {
2097 		s3c24xx_serial_cpufreq_deregister(to_ourport(port));
2098 		uart_remove_one_port(&s3c24xx_uart_drv, port);
2099 	}
2100 
2101 	uart_unregister_driver(&s3c24xx_uart_drv);
2102 
2103 	return 0;
2104 }
2105 
2106 /* UART power management code */
2107 #ifdef CONFIG_PM_SLEEP
2108 static int s3c24xx_serial_suspend(struct device *dev)
2109 {
2110 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2111 
2112 	if (port)
2113 		uart_suspend_port(&s3c24xx_uart_drv, port);
2114 
2115 	return 0;
2116 }
2117 
2118 static int s3c24xx_serial_resume(struct device *dev)
2119 {
2120 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2121 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2122 
2123 	if (port) {
2124 		clk_prepare_enable(ourport->clk);
2125 		if (!IS_ERR(ourport->baudclk))
2126 			clk_prepare_enable(ourport->baudclk);
2127 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
2128 		if (!IS_ERR(ourport->baudclk))
2129 			clk_disable_unprepare(ourport->baudclk);
2130 		clk_disable_unprepare(ourport->clk);
2131 
2132 		uart_resume_port(&s3c24xx_uart_drv, port);
2133 	}
2134 
2135 	return 0;
2136 }
2137 
2138 static int s3c24xx_serial_resume_noirq(struct device *dev)
2139 {
2140 	struct uart_port *port = s3c24xx_dev_to_port(dev);
2141 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2142 
2143 	if (port) {
2144 		/* restore IRQ mask */
2145 		if (s3c24xx_serial_has_interrupt_mask(port)) {
2146 			unsigned int uintm = 0xf;
2147 
2148 			if (ourport->tx_enabled)
2149 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
2150 			if (ourport->rx_enabled)
2151 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
2152 			clk_prepare_enable(ourport->clk);
2153 			if (!IS_ERR(ourport->baudclk))
2154 				clk_prepare_enable(ourport->baudclk);
2155 			wr_regl(port, S3C64XX_UINTM, uintm);
2156 			if (!IS_ERR(ourport->baudclk))
2157 				clk_disable_unprepare(ourport->baudclk);
2158 			clk_disable_unprepare(ourport->clk);
2159 		}
2160 	}
2161 
2162 	return 0;
2163 }
2164 
2165 static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
2166 	.suspend = s3c24xx_serial_suspend,
2167 	.resume = s3c24xx_serial_resume,
2168 	.resume_noirq = s3c24xx_serial_resume_noirq,
2169 };
2170 #define SERIAL_SAMSUNG_PM_OPS	(&s3c24xx_serial_pm_ops)
2171 
2172 #else /* !CONFIG_PM_SLEEP */
2173 
2174 #define SERIAL_SAMSUNG_PM_OPS	NULL
2175 #endif /* CONFIG_PM_SLEEP */
2176 
2177 /* Console code */
2178 
2179 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2180 
2181 static struct uart_port *cons_uart;
2182 
2183 static int
2184 s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
2185 {
2186 	struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
2187 	unsigned long ufstat, utrstat;
2188 
2189 	if (ufcon & S3C2410_UFCON_FIFOMODE) {
2190 		/* fifo mode - check amount of data in fifo registers... */
2191 
2192 		ufstat = rd_regl(port, S3C2410_UFSTAT);
2193 		return (ufstat & info->tx_fifofull) ? 0 : 1;
2194 	}
2195 
2196 	/* in non-fifo mode, we go and use the tx buffer empty */
2197 
2198 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
2199 	return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
2200 }
2201 
2202 static bool
2203 s3c24xx_port_configured(unsigned int ucon)
2204 {
2205 	/* consider the serial port configured if the tx/rx mode set */
2206 	return (ucon & 0xf) != 0;
2207 }
2208 
2209 #ifdef CONFIG_CONSOLE_POLL
2210 /*
2211  * Console polling routines for writing and reading from the uart while
2212  * in an interrupt or debug context.
2213  */
2214 
2215 static int s3c24xx_serial_get_poll_char(struct uart_port *port)
2216 {
2217 	struct s3c24xx_uart_port *ourport = to_ourport(port);
2218 	unsigned int ufstat;
2219 
2220 	ufstat = rd_regl(port, S3C2410_UFSTAT);
2221 	if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
2222 		return NO_POLL_CHAR;
2223 
2224 	return rd_reg(port, S3C2410_URXH);
2225 }
2226 
2227 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
2228 		unsigned char c)
2229 {
2230 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2231 	unsigned int ucon = rd_regl(port, S3C2410_UCON);
2232 
2233 	/* not possible to xmit on unconfigured port */
2234 	if (!s3c24xx_port_configured(ucon))
2235 		return;
2236 
2237 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2238 		cpu_relax();
2239 	wr_reg(port, S3C2410_UTXH, c);
2240 }
2241 
2242 #endif /* CONFIG_CONSOLE_POLL */
2243 
2244 static void
2245 s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
2246 {
2247 	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
2248 
2249 	while (!s3c24xx_serial_console_txrdy(port, ufcon))
2250 		cpu_relax();
2251 	wr_reg(port, S3C2410_UTXH, ch);
2252 }
2253 
2254 static void
2255 s3c24xx_serial_console_write(struct console *co, const char *s,
2256 			     unsigned int count)
2257 {
2258 	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
2259 
2260 	/* not possible to xmit on unconfigured port */
2261 	if (!s3c24xx_port_configured(ucon))
2262 		return;
2263 
2264 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
2265 }
2266 
2267 static void __init
2268 s3c24xx_serial_get_options(struct uart_port *port, int *baud,
2269 			   int *parity, int *bits)
2270 {
2271 	struct clk *clk;
2272 	unsigned int ulcon;
2273 	unsigned int ucon;
2274 	unsigned int ubrdiv;
2275 	unsigned long rate;
2276 	unsigned int clk_sel;
2277 	char clk_name[MAX_CLK_NAME_LENGTH];
2278 
2279 	ulcon  = rd_regl(port, S3C2410_ULCON);
2280 	ucon   = rd_regl(port, S3C2410_UCON);
2281 	ubrdiv = rd_regl(port, S3C2410_UBRDIV);
2282 
2283 	if (s3c24xx_port_configured(ucon)) {
2284 		switch (ulcon & S3C2410_LCON_CSMASK) {
2285 		case S3C2410_LCON_CS5:
2286 			*bits = 5;
2287 			break;
2288 		case S3C2410_LCON_CS6:
2289 			*bits = 6;
2290 			break;
2291 		case S3C2410_LCON_CS7:
2292 			*bits = 7;
2293 			break;
2294 		case S3C2410_LCON_CS8:
2295 		default:
2296 			*bits = 8;
2297 			break;
2298 		}
2299 
2300 		switch (ulcon & S3C2410_LCON_PMASK) {
2301 		case S3C2410_LCON_PEVEN:
2302 			*parity = 'e';
2303 			break;
2304 
2305 		case S3C2410_LCON_PODD:
2306 			*parity = 'o';
2307 			break;
2308 
2309 		case S3C2410_LCON_PNONE:
2310 		default:
2311 			*parity = 'n';
2312 		}
2313 
2314 		/* now calculate the baud rate */
2315 
2316 		clk_sel = s3c24xx_serial_getsource(port);
2317 		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
2318 
2319 		clk = clk_get(port->dev, clk_name);
2320 		if (!IS_ERR(clk))
2321 			rate = clk_get_rate(clk);
2322 		else
2323 			rate = 1;
2324 
2325 		*baud = rate / (16 * (ubrdiv + 1));
2326 		dev_dbg(port->dev, "calculated baud %d\n", *baud);
2327 	}
2328 }
2329 
2330 static int __init
2331 s3c24xx_serial_console_setup(struct console *co, char *options)
2332 {
2333 	struct uart_port *port;
2334 	int baud = 9600;
2335 	int bits = 8;
2336 	int parity = 'n';
2337 	int flow = 'n';
2338 
2339 	/* is this a valid port */
2340 
2341 	if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
2342 		co->index = 0;
2343 
2344 	port = &s3c24xx_serial_ports[co->index].port;
2345 
2346 	/* is the port configured? */
2347 
2348 	if (port->mapbase == 0x0)
2349 		return -ENODEV;
2350 
2351 	cons_uart = port;
2352 
2353 	/*
2354 	 * Check whether an invalid uart number has been specified, and
2355 	 * if so, search for the first available port that does have
2356 	 * console support.
2357 	 */
2358 	if (options)
2359 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2360 	else
2361 		s3c24xx_serial_get_options(port, &baud, &parity, &bits);
2362 
2363 	dev_dbg(port->dev, "baud %d\n", baud);
2364 
2365 	return uart_set_options(port, co, baud, parity, bits, flow);
2366 }
2367 
2368 static struct console s3c24xx_serial_console = {
2369 	.name		= S3C24XX_SERIAL_NAME,
2370 	.device		= uart_console_device,
2371 	.flags		= CON_PRINTBUFFER,
2372 	.index		= -1,
2373 	.write		= s3c24xx_serial_console_write,
2374 	.setup		= s3c24xx_serial_console_setup,
2375 	.data		= &s3c24xx_uart_drv,
2376 };
2377 #endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
2378 
2379 #ifdef CONFIG_CPU_S3C2410
2380 static struct s3c24xx_serial_drv_data s3c2410_serial_drv_data = {
2381 	.info = &(struct s3c24xx_uart_info) {
2382 		.name		= "Samsung S3C2410 UART",
2383 		.type		= PORT_S3C2410,
2384 		.fifosize	= 16,
2385 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
2386 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
2387 		.rx_fifofull	= S3C2410_UFSTAT_RXFULL,
2388 		.tx_fifofull	= S3C2410_UFSTAT_TXFULL,
2389 		.tx_fifomask	= S3C2410_UFSTAT_TXMASK,
2390 		.tx_fifoshift	= S3C2410_UFSTAT_TXSHIFT,
2391 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2392 		.num_clks	= 2,
2393 		.clksel_mask	= S3C2410_UCON_CLKMASK,
2394 		.clksel_shift	= S3C2410_UCON_CLKSHIFT,
2395 	},
2396 	.def_cfg = &(struct s3c2410_uartcfg) {
2397 		.ucon		= S3C2410_UCON_DEFAULT,
2398 		.ufcon		= S3C2410_UFCON_DEFAULT,
2399 	},
2400 };
2401 #define S3C2410_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2410_serial_drv_data)
2402 #else
2403 #define S3C2410_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2404 #endif
2405 
2406 #ifdef CONFIG_CPU_S3C2412
2407 static struct s3c24xx_serial_drv_data s3c2412_serial_drv_data = {
2408 	.info = &(struct s3c24xx_uart_info) {
2409 		.name		= "Samsung S3C2412 UART",
2410 		.type		= PORT_S3C2412,
2411 		.fifosize	= 64,
2412 		.has_divslot	= 1,
2413 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2414 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2415 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2416 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2417 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2418 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2419 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2420 		.num_clks	= 4,
2421 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2422 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2423 	},
2424 	.def_cfg = &(struct s3c2410_uartcfg) {
2425 		.ucon		= S3C2410_UCON_DEFAULT,
2426 		.ufcon		= S3C2410_UFCON_DEFAULT,
2427 	},
2428 };
2429 #define S3C2412_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2412_serial_drv_data)
2430 #else
2431 #define S3C2412_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2432 #endif
2433 
2434 #if defined(CONFIG_CPU_S3C2440) || defined(CONFIG_CPU_S3C2416) || \
2435 	defined(CONFIG_CPU_S3C2443) || defined(CONFIG_CPU_S3C2442)
2436 static struct s3c24xx_serial_drv_data s3c2440_serial_drv_data = {
2437 	.info = &(struct s3c24xx_uart_info) {
2438 		.name		= "Samsung S3C2440 UART",
2439 		.type		= PORT_S3C2440,
2440 		.fifosize	= 64,
2441 		.has_divslot	= 1,
2442 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2443 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2444 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2445 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2446 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2447 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2448 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2449 		.num_clks	= 4,
2450 		.clksel_mask	= S3C2412_UCON_CLKMASK,
2451 		.clksel_shift	= S3C2412_UCON_CLKSHIFT,
2452 	},
2453 	.def_cfg = &(struct s3c2410_uartcfg) {
2454 		.ucon		= S3C2410_UCON_DEFAULT,
2455 		.ufcon		= S3C2410_UFCON_DEFAULT,
2456 	},
2457 };
2458 #define S3C2440_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c2440_serial_drv_data)
2459 #else
2460 #define S3C2440_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2461 #endif
2462 
2463 #if defined(CONFIG_CPU_S3C6400) || defined(CONFIG_CPU_S3C6410)
2464 static struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
2465 	.info = &(struct s3c24xx_uart_info) {
2466 		.name		= "Samsung S3C6400 UART",
2467 		.type		= PORT_S3C6400,
2468 		.fifosize	= 64,
2469 		.has_divslot	= 1,
2470 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
2471 		.rx_fifoshift	= S3C2440_UFSTAT_RXSHIFT,
2472 		.rx_fifofull	= S3C2440_UFSTAT_RXFULL,
2473 		.tx_fifofull	= S3C2440_UFSTAT_TXFULL,
2474 		.tx_fifomask	= S3C2440_UFSTAT_TXMASK,
2475 		.tx_fifoshift	= S3C2440_UFSTAT_TXSHIFT,
2476 		.def_clk_sel	= S3C2410_UCON_CLKSEL2,
2477 		.num_clks	= 4,
2478 		.clksel_mask	= S3C6400_UCON_CLKMASK,
2479 		.clksel_shift	= S3C6400_UCON_CLKSHIFT,
2480 	},
2481 	.def_cfg = &(struct s3c2410_uartcfg) {
2482 		.ucon		= S3C2410_UCON_DEFAULT,
2483 		.ufcon		= S3C2410_UFCON_DEFAULT,
2484 	},
2485 };
2486 #define S3C6400_SERIAL_DRV_DATA ((kernel_ulong_t)&s3c6400_serial_drv_data)
2487 #else
2488 #define S3C6400_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2489 #endif
2490 
2491 #ifdef CONFIG_CPU_S5PV210
2492 static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
2493 	.info = &(struct s3c24xx_uart_info) {
2494 		.name		= "Samsung S5PV210 UART",
2495 		.type		= PORT_S3C6400,
2496 		.has_divslot	= 1,
2497 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
2498 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
2499 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
2500 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
2501 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
2502 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
2503 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
2504 		.num_clks	= 2,
2505 		.clksel_mask	= S5PV210_UCON_CLKMASK,
2506 		.clksel_shift	= S5PV210_UCON_CLKSHIFT,
2507 	},
2508 	.def_cfg = &(struct s3c2410_uartcfg) {
2509 		.ucon		= S5PV210_UCON_DEFAULT,
2510 		.ufcon		= S5PV210_UFCON_DEFAULT,
2511 	},
2512 	.fifosize = { 256, 64, 16, 16 },
2513 };
2514 #define S5PV210_SERIAL_DRV_DATA ((kernel_ulong_t)&s5pv210_serial_drv_data)
2515 #else
2516 #define S5PV210_SERIAL_DRV_DATA	(kernel_ulong_t)NULL
2517 #endif
2518 
2519 #if defined(CONFIG_ARCH_EXYNOS)
2520 #define EXYNOS_COMMON_SERIAL_DRV_DATA				\
2521 	.info = &(struct s3c24xx_uart_info) {			\
2522 		.name		= "Samsung Exynos UART",	\
2523 		.type		= PORT_S3C6400,			\
2524 		.has_divslot	= 1,				\
2525 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
2526 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
2527 		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,	\
2528 		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,	\
2529 		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,	\
2530 		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,	\
2531 		.def_clk_sel	= S3C2410_UCON_CLKSEL0,		\
2532 		.num_clks	= 1,				\
2533 		.clksel_mask	= 0,				\
2534 		.clksel_shift	= 0,				\
2535 	},							\
2536 	.def_cfg = &(struct s3c2410_uartcfg) {			\
2537 		.ucon		= S5PV210_UCON_DEFAULT,		\
2538 		.ufcon		= S5PV210_UFCON_DEFAULT,	\
2539 		.has_fracval	= 1,				\
2540 	}							\
2541 
2542 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
2543 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2544 	.fifosize = { 256, 64, 16, 16 },
2545 };
2546 
2547 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
2548 	EXYNOS_COMMON_SERIAL_DRV_DATA,
2549 	.fifosize = { 64, 256, 16, 256 },
2550 };
2551 
2552 #define EXYNOS4210_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos4210_serial_drv_data)
2553 #define EXYNOS5433_SERIAL_DRV_DATA ((kernel_ulong_t)&exynos5433_serial_drv_data)
2554 #else
2555 #define EXYNOS4210_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2556 #define EXYNOS5433_SERIAL_DRV_DATA (kernel_ulong_t)NULL
2557 #endif
2558 
2559 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
2560 	{
2561 		.name		= "s3c2410-uart",
2562 		.driver_data	= S3C2410_SERIAL_DRV_DATA,
2563 	}, {
2564 		.name		= "s3c2412-uart",
2565 		.driver_data	= S3C2412_SERIAL_DRV_DATA,
2566 	}, {
2567 		.name		= "s3c2440-uart",
2568 		.driver_data	= S3C2440_SERIAL_DRV_DATA,
2569 	}, {
2570 		.name		= "s3c6400-uart",
2571 		.driver_data	= S3C6400_SERIAL_DRV_DATA,
2572 	}, {
2573 		.name		= "s5pv210-uart",
2574 		.driver_data	= S5PV210_SERIAL_DRV_DATA,
2575 	}, {
2576 		.name		= "exynos4210-uart",
2577 		.driver_data	= EXYNOS4210_SERIAL_DRV_DATA,
2578 	}, {
2579 		.name		= "exynos5433-uart",
2580 		.driver_data	= EXYNOS5433_SERIAL_DRV_DATA,
2581 	},
2582 	{ },
2583 };
2584 MODULE_DEVICE_TABLE(platform, s3c24xx_serial_driver_ids);
2585 
2586 #ifdef CONFIG_OF
2587 static const struct of_device_id s3c24xx_uart_dt_match[] = {
2588 	{ .compatible = "samsung,s3c2410-uart",
2589 		.data = (void *)S3C2410_SERIAL_DRV_DATA },
2590 	{ .compatible = "samsung,s3c2412-uart",
2591 		.data = (void *)S3C2412_SERIAL_DRV_DATA },
2592 	{ .compatible = "samsung,s3c2440-uart",
2593 		.data = (void *)S3C2440_SERIAL_DRV_DATA },
2594 	{ .compatible = "samsung,s3c6400-uart",
2595 		.data = (void *)S3C6400_SERIAL_DRV_DATA },
2596 	{ .compatible = "samsung,s5pv210-uart",
2597 		.data = (void *)S5PV210_SERIAL_DRV_DATA },
2598 	{ .compatible = "samsung,exynos4210-uart",
2599 		.data = (void *)EXYNOS4210_SERIAL_DRV_DATA },
2600 	{ .compatible = "samsung,exynos5433-uart",
2601 		.data = (void *)EXYNOS5433_SERIAL_DRV_DATA },
2602 	{},
2603 };
2604 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
2605 #endif
2606 
2607 static struct platform_driver samsung_serial_driver = {
2608 	.probe		= s3c24xx_serial_probe,
2609 	.remove		= s3c24xx_serial_remove,
2610 	.id_table	= s3c24xx_serial_driver_ids,
2611 	.driver		= {
2612 		.name	= "samsung-uart",
2613 		.pm	= SERIAL_SAMSUNG_PM_OPS,
2614 		.of_match_table	= of_match_ptr(s3c24xx_uart_dt_match),
2615 	},
2616 };
2617 
2618 module_platform_driver(samsung_serial_driver);
2619 
2620 #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
2621 /*
2622  * Early console.
2623  */
2624 
2625 static void wr_reg_barrier(struct uart_port *port, u32 reg, u32 val)
2626 {
2627 	switch (port->iotype) {
2628 	case UPIO_MEM:
2629 		writeb(val, portaddr(port, reg));
2630 		break;
2631 	case UPIO_MEM32:
2632 		writel(val, portaddr(port, reg));
2633 		break;
2634 	}
2635 }
2636 
2637 struct samsung_early_console_data {
2638 	u32 txfull_mask;
2639 };
2640 
2641 static void samsung_early_busyuart(struct uart_port *port)
2642 {
2643 	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
2644 		;
2645 }
2646 
2647 static void samsung_early_busyuart_fifo(struct uart_port *port)
2648 {
2649 	struct samsung_early_console_data *data = port->private_data;
2650 
2651 	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
2652 		;
2653 }
2654 
2655 static void samsung_early_putc(struct uart_port *port, int c)
2656 {
2657 	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
2658 		samsung_early_busyuart_fifo(port);
2659 	else
2660 		samsung_early_busyuart(port);
2661 
2662 	wr_reg_barrier(port, S3C2410_UTXH, c);
2663 }
2664 
2665 static void samsung_early_write(struct console *con, const char *s,
2666 				unsigned int n)
2667 {
2668 	struct earlycon_device *dev = con->data;
2669 
2670 	uart_console_write(&dev->port, s, n, samsung_early_putc);
2671 }
2672 
2673 static int __init samsung_early_console_setup(struct earlycon_device *device,
2674 					      const char *opt)
2675 {
2676 	if (!device->port.membase)
2677 		return -ENODEV;
2678 
2679 	device->con->write = samsung_early_write;
2680 	return 0;
2681 }
2682 
2683 /* S3C2410 */
2684 static struct samsung_early_console_data s3c2410_early_console_data = {
2685 	.txfull_mask = S3C2410_UFSTAT_TXFULL,
2686 };
2687 
2688 static int __init s3c2410_early_console_setup(struct earlycon_device *device,
2689 					      const char *opt)
2690 {
2691 	device->port.private_data = &s3c2410_early_console_data;
2692 	return samsung_early_console_setup(device, opt);
2693 }
2694 
2695 OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
2696 			s3c2410_early_console_setup);
2697 
2698 /* S3C2412, S3C2440, S3C64xx */
2699 static struct samsung_early_console_data s3c2440_early_console_data = {
2700 	.txfull_mask = S3C2440_UFSTAT_TXFULL,
2701 };
2702 
2703 static int __init s3c2440_early_console_setup(struct earlycon_device *device,
2704 					      const char *opt)
2705 {
2706 	device->port.private_data = &s3c2440_early_console_data;
2707 	return samsung_early_console_setup(device, opt);
2708 }
2709 
2710 OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
2711 			s3c2440_early_console_setup);
2712 OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
2713 			s3c2440_early_console_setup);
2714 OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
2715 			s3c2440_early_console_setup);
2716 
2717 /* S5PV210, Exynos */
2718 static struct samsung_early_console_data s5pv210_early_console_data = {
2719 	.txfull_mask = S5PV210_UFSTAT_TXFULL,
2720 };
2721 
2722 static int __init s5pv210_early_console_setup(struct earlycon_device *device,
2723 					      const char *opt)
2724 {
2725 	device->port.private_data = &s5pv210_early_console_data;
2726 	return samsung_early_console_setup(device, opt);
2727 }
2728 
2729 OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
2730 			s5pv210_early_console_setup);
2731 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
2732 			s5pv210_early_console_setup);
2733 #endif
2734 
2735 MODULE_ALIAS("platform:samsung-uart");
2736 MODULE_DESCRIPTION("Samsung SoC Serial port driver");
2737 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
2738 MODULE_LICENSE("GPL v2");
2739