xref: /openbmc/linux/drivers/tty/serial/msm_serial.c (revision 565d76cb)
1 /*
2  * drivers/serial/msm_serial.c - driver for msm7k serial device and console
3  *
4  * Copyright (C) 2007 Google, Inc.
5  * Author: Robert Love <rlove@google.com>
6  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
7  *
8  * This software is licensed under the terms of the GNU General Public
9  * License version 2, as published by the Free Software Foundation, and
10  * may be copied, distributed, and modified under those terms.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 # define SUPPORT_SYSRQ
20 #endif
21 
22 #include <linux/hrtimer.h>
23 #include <linux/module.h>
24 #include <linux/io.h>
25 #include <linux/ioport.h>
26 #include <linux/irq.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/tty.h>
30 #include <linux/tty_flip.h>
31 #include <linux/serial_core.h>
32 #include <linux/serial.h>
33 #include <linux/clk.h>
34 #include <linux/platform_device.h>
35 #include <linux/delay.h>
36 
37 #include "msm_serial.h"
38 
39 struct msm_port {
40 	struct uart_port	uart;
41 	char			name[16];
42 	struct clk		*clk;
43 	struct clk		*pclk;
44 	unsigned int		imr;
45 	unsigned int            *gsbi_base;
46 	int			is_uartdm;
47 	unsigned int		old_snap_state;
48 };
49 
50 static inline void wait_for_xmitr(struct uart_port *port, int bits)
51 {
52 	if (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY))
53 		while ((msm_read(port, UART_ISR) & bits) != bits)
54 			cpu_relax();
55 }
56 
57 static void msm_stop_tx(struct uart_port *port)
58 {
59 	struct msm_port *msm_port = UART_TO_MSM(port);
60 
61 	msm_port->imr &= ~UART_IMR_TXLEV;
62 	msm_write(port, msm_port->imr, UART_IMR);
63 }
64 
65 static void msm_start_tx(struct uart_port *port)
66 {
67 	struct msm_port *msm_port = UART_TO_MSM(port);
68 
69 	msm_port->imr |= UART_IMR_TXLEV;
70 	msm_write(port, msm_port->imr, UART_IMR);
71 }
72 
73 static void msm_stop_rx(struct uart_port *port)
74 {
75 	struct msm_port *msm_port = UART_TO_MSM(port);
76 
77 	msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
78 	msm_write(port, msm_port->imr, UART_IMR);
79 }
80 
81 static void msm_enable_ms(struct uart_port *port)
82 {
83 	struct msm_port *msm_port = UART_TO_MSM(port);
84 
85 	msm_port->imr |= UART_IMR_DELTA_CTS;
86 	msm_write(port, msm_port->imr, UART_IMR);
87 }
88 
89 static void handle_rx_dm(struct uart_port *port, unsigned int misr)
90 {
91 	struct tty_struct *tty = port->state->port.tty;
92 	unsigned int sr;
93 	int count = 0;
94 	struct msm_port *msm_port = UART_TO_MSM(port);
95 
96 	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
97 		port->icount.overrun++;
98 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
99 		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
100 	}
101 
102 	if (misr & UART_IMR_RXSTALE) {
103 		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
104 			msm_port->old_snap_state;
105 		msm_port->old_snap_state = 0;
106 	} else {
107 		count = 4 * (msm_read(port, UART_RFWR));
108 		msm_port->old_snap_state += count;
109 	}
110 
111 	/* TODO: Precise error reporting */
112 
113 	port->icount.rx += count;
114 
115 	while (count > 0) {
116 		unsigned int c;
117 
118 		sr = msm_read(port, UART_SR);
119 		if ((sr & UART_SR_RX_READY) == 0) {
120 			msm_port->old_snap_state -= count;
121 			break;
122 		}
123 		c = msm_read(port, UARTDM_RF);
124 		if (sr & UART_SR_RX_BREAK) {
125 			port->icount.brk++;
126 			if (uart_handle_break(port))
127 				continue;
128 		} else if (sr & UART_SR_PAR_FRAME_ERR)
129 			port->icount.frame++;
130 
131 		/* TODO: handle sysrq */
132 		tty_insert_flip_string(tty, (char *) &c,
133 				       (count > 4) ? 4 : count);
134 		count -= 4;
135 	}
136 
137 	tty_flip_buffer_push(tty);
138 	if (misr & (UART_IMR_RXSTALE))
139 		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
140 	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
141 	msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
142 }
143 
144 static void handle_rx(struct uart_port *port)
145 {
146 	struct tty_struct *tty = port->state->port.tty;
147 	unsigned int sr;
148 
149 	/*
150 	 * Handle overrun. My understanding of the hardware is that overrun
151 	 * is not tied to the RX buffer, so we handle the case out of band.
152 	 */
153 	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
154 		port->icount.overrun++;
155 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
156 		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
157 	}
158 
159 	/* and now the main RX loop */
160 	while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
161 		unsigned int c;
162 		char flag = TTY_NORMAL;
163 
164 		c = msm_read(port, UART_RF);
165 
166 		if (sr & UART_SR_RX_BREAK) {
167 			port->icount.brk++;
168 			if (uart_handle_break(port))
169 				continue;
170 		} else if (sr & UART_SR_PAR_FRAME_ERR) {
171 			port->icount.frame++;
172 		} else {
173 			port->icount.rx++;
174 		}
175 
176 		/* Mask conditions we're ignorning. */
177 		sr &= port->read_status_mask;
178 
179 		if (sr & UART_SR_RX_BREAK) {
180 			flag = TTY_BREAK;
181 		} else if (sr & UART_SR_PAR_FRAME_ERR) {
182 			flag = TTY_FRAME;
183 		}
184 
185 		if (!uart_handle_sysrq_char(port, c))
186 			tty_insert_flip_char(tty, c, flag);
187 	}
188 
189 	tty_flip_buffer_push(tty);
190 }
191 
192 static void reset_dm_count(struct uart_port *port)
193 {
194 	wait_for_xmitr(port, UART_ISR_TX_READY);
195 	msm_write(port, 1, UARTDM_NCF_TX);
196 }
197 
198 static void handle_tx(struct uart_port *port)
199 {
200 	struct circ_buf *xmit = &port->state->xmit;
201 	struct msm_port *msm_port = UART_TO_MSM(port);
202 	int sent_tx;
203 
204 	if (port->x_char) {
205 		if (msm_port->is_uartdm)
206 			reset_dm_count(port);
207 
208 		msm_write(port, port->x_char,
209 			  msm_port->is_uartdm ? UARTDM_TF : UART_TF);
210 		port->icount.tx++;
211 		port->x_char = 0;
212 	}
213 
214 	if (msm_port->is_uartdm)
215 		reset_dm_count(port);
216 
217 	while (msm_read(port, UART_SR) & UART_SR_TX_READY) {
218 		if (uart_circ_empty(xmit)) {
219 			/* disable tx interrupts */
220 			msm_port->imr &= ~UART_IMR_TXLEV;
221 			msm_write(port, msm_port->imr, UART_IMR);
222 			break;
223 		}
224 		msm_write(port, xmit->buf[xmit->tail],
225 			  msm_port->is_uartdm ? UARTDM_TF : UART_TF);
226 
227 		if (msm_port->is_uartdm)
228 			reset_dm_count(port);
229 
230 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
231 		port->icount.tx++;
232 		sent_tx = 1;
233 	}
234 
235 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
236 		uart_write_wakeup(port);
237 }
238 
239 static void handle_delta_cts(struct uart_port *port)
240 {
241 	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
242 	port->icount.cts++;
243 	wake_up_interruptible(&port->state->port.delta_msr_wait);
244 }
245 
246 static irqreturn_t msm_irq(int irq, void *dev_id)
247 {
248 	struct uart_port *port = dev_id;
249 	struct msm_port *msm_port = UART_TO_MSM(port);
250 	unsigned int misr;
251 
252 	spin_lock(&port->lock);
253 	misr = msm_read(port, UART_MISR);
254 	msm_write(port, 0, UART_IMR); /* disable interrupt */
255 
256 	if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
257 		if (msm_port->is_uartdm)
258 			handle_rx_dm(port, misr);
259 		else
260 			handle_rx(port);
261 	}
262 	if (misr & UART_IMR_TXLEV)
263 		handle_tx(port);
264 	if (misr & UART_IMR_DELTA_CTS)
265 		handle_delta_cts(port);
266 
267 	msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
268 	spin_unlock(&port->lock);
269 
270 	return IRQ_HANDLED;
271 }
272 
273 static unsigned int msm_tx_empty(struct uart_port *port)
274 {
275 	return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
276 }
277 
278 static unsigned int msm_get_mctrl(struct uart_port *port)
279 {
280 	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
281 }
282 
283 
284 static void msm_reset(struct uart_port *port)
285 {
286 	/* reset everything */
287 	msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
288 	msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
289 	msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
290 	msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
291 	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
292 	msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
293 }
294 
295 void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
296 {
297 	unsigned int mr;
298 	mr = msm_read(port, UART_MR1);
299 
300 	if (!(mctrl & TIOCM_RTS)) {
301 		mr &= ~UART_MR1_RX_RDY_CTL;
302 		msm_write(port, mr, UART_MR1);
303 		msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
304 	} else {
305 		mr |= UART_MR1_RX_RDY_CTL;
306 		msm_write(port, mr, UART_MR1);
307 	}
308 }
309 
310 static void msm_break_ctl(struct uart_port *port, int break_ctl)
311 {
312 	if (break_ctl)
313 		msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
314 	else
315 		msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
316 }
317 
318 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud)
319 {
320 	unsigned int baud_code, rxstale, watermark;
321 	struct msm_port *msm_port = UART_TO_MSM(port);
322 
323 	switch (baud) {
324 	case 300:
325 		baud_code = UART_CSR_300;
326 		rxstale = 1;
327 		break;
328 	case 600:
329 		baud_code = UART_CSR_600;
330 		rxstale = 1;
331 		break;
332 	case 1200:
333 		baud_code = UART_CSR_1200;
334 		rxstale = 1;
335 		break;
336 	case 2400:
337 		baud_code = UART_CSR_2400;
338 		rxstale = 1;
339 		break;
340 	case 4800:
341 		baud_code = UART_CSR_4800;
342 		rxstale = 1;
343 		break;
344 	case 9600:
345 		baud_code = UART_CSR_9600;
346 		rxstale = 2;
347 		break;
348 	case 14400:
349 		baud_code = UART_CSR_14400;
350 		rxstale = 3;
351 		break;
352 	case 19200:
353 		baud_code = UART_CSR_19200;
354 		rxstale = 4;
355 		break;
356 	case 28800:
357 		baud_code = UART_CSR_28800;
358 		rxstale = 6;
359 		break;
360 	case 38400:
361 		baud_code = UART_CSR_38400;
362 		rxstale = 8;
363 		break;
364 	case 57600:
365 		baud_code = UART_CSR_57600;
366 		rxstale = 16;
367 		break;
368 	case 115200:
369 	default:
370 		baud_code = UART_CSR_115200;
371 		baud = 115200;
372 		rxstale = 31;
373 		break;
374 	}
375 
376 	if (msm_port->is_uartdm)
377 		msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
378 
379 	msm_write(port, baud_code, UART_CSR);
380 
381 	/* RX stale watermark */
382 	watermark = UART_IPR_STALE_LSB & rxstale;
383 	watermark |= UART_IPR_RXSTALE_LAST;
384 	watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
385 	msm_write(port, watermark, UART_IPR);
386 
387 	/* set RX watermark */
388 	watermark = (port->fifosize * 3) / 4;
389 	msm_write(port, watermark, UART_RFWR);
390 
391 	/* set TX watermark */
392 	msm_write(port, 10, UART_TFWR);
393 
394 	if (msm_port->is_uartdm) {
395 		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
396 		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
397 		msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
398 	}
399 
400 	return baud;
401 }
402 
403 
404 static void msm_init_clock(struct uart_port *port)
405 {
406 	struct msm_port *msm_port = UART_TO_MSM(port);
407 
408 	clk_enable(msm_port->clk);
409 	if (!IS_ERR(msm_port->pclk))
410 		clk_enable(msm_port->pclk);
411 	msm_serial_set_mnd_regs(port);
412 }
413 
414 static int msm_startup(struct uart_port *port)
415 {
416 	struct msm_port *msm_port = UART_TO_MSM(port);
417 	unsigned int data, rfr_level;
418 	int ret;
419 
420 	snprintf(msm_port->name, sizeof(msm_port->name),
421 		 "msm_serial%d", port->line);
422 
423 	ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH,
424 			  msm_port->name, port);
425 	if (unlikely(ret))
426 		return ret;
427 
428 	msm_init_clock(port);
429 
430 	if (likely(port->fifosize > 12))
431 		rfr_level = port->fifosize - 12;
432 	else
433 		rfr_level = port->fifosize;
434 
435 	/* set automatic RFR level */
436 	data = msm_read(port, UART_MR1);
437 	data &= ~UART_MR1_AUTO_RFR_LEVEL1;
438 	data &= ~UART_MR1_AUTO_RFR_LEVEL0;
439 	data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2);
440 	data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
441 	msm_write(port, data, UART_MR1);
442 
443 	/* make sure that RXSTALE count is non-zero */
444 	data = msm_read(port, UART_IPR);
445 	if (unlikely(!data)) {
446 		data |= UART_IPR_RXSTALE_LAST;
447 		data |= UART_IPR_STALE_LSB;
448 		msm_write(port, data, UART_IPR);
449 	}
450 
451 	data = 0;
452 	if (!port->cons || (port->cons && !(port->cons->flags & CON_ENABLED))) {
453 		msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
454 		msm_reset(port);
455 		data = UART_CR_TX_ENABLE;
456 	}
457 
458 	data |= UART_CR_RX_ENABLE;
459 	msm_write(port, data, UART_CR);	/* enable TX & RX */
460 
461 	/* Make sure IPR is not 0 to start with*/
462 	if (msm_port->is_uartdm)
463 		msm_write(port, UART_IPR_STALE_LSB, UART_IPR);
464 
465 	/* turn on RX and CTS interrupts */
466 	msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
467 			UART_IMR_CURRENT_CTS;
468 
469 	if (msm_port->is_uartdm) {
470 		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
471 		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
472 		msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
473 	}
474 
475 	msm_write(port, msm_port->imr, UART_IMR);
476 	return 0;
477 }
478 
479 static void msm_shutdown(struct uart_port *port)
480 {
481 	struct msm_port *msm_port = UART_TO_MSM(port);
482 
483 	msm_port->imr = 0;
484 	msm_write(port, 0, UART_IMR); /* disable interrupts */
485 
486 	clk_disable(msm_port->clk);
487 
488 	free_irq(port->irq, port);
489 }
490 
491 static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
492 			    struct ktermios *old)
493 {
494 	unsigned long flags;
495 	unsigned int baud, mr;
496 
497 	spin_lock_irqsave(&port->lock, flags);
498 
499 	/* calculate and set baud rate */
500 	baud = uart_get_baud_rate(port, termios, old, 300, 115200);
501 	baud = msm_set_baud_rate(port, baud);
502 	if (tty_termios_baud_rate(termios))
503 		tty_termios_encode_baud_rate(termios, baud, baud);
504 
505 	/* calculate parity */
506 	mr = msm_read(port, UART_MR2);
507 	mr &= ~UART_MR2_PARITY_MODE;
508 	if (termios->c_cflag & PARENB) {
509 		if (termios->c_cflag & PARODD)
510 			mr |= UART_MR2_PARITY_MODE_ODD;
511 		else if (termios->c_cflag & CMSPAR)
512 			mr |= UART_MR2_PARITY_MODE_SPACE;
513 		else
514 			mr |= UART_MR2_PARITY_MODE_EVEN;
515 	}
516 
517 	/* calculate bits per char */
518 	mr &= ~UART_MR2_BITS_PER_CHAR;
519 	switch (termios->c_cflag & CSIZE) {
520 	case CS5:
521 		mr |= UART_MR2_BITS_PER_CHAR_5;
522 		break;
523 	case CS6:
524 		mr |= UART_MR2_BITS_PER_CHAR_6;
525 		break;
526 	case CS7:
527 		mr |= UART_MR2_BITS_PER_CHAR_7;
528 		break;
529 	case CS8:
530 	default:
531 		mr |= UART_MR2_BITS_PER_CHAR_8;
532 		break;
533 	}
534 
535 	/* calculate stop bits */
536 	mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
537 	if (termios->c_cflag & CSTOPB)
538 		mr |= UART_MR2_STOP_BIT_LEN_TWO;
539 	else
540 		mr |= UART_MR2_STOP_BIT_LEN_ONE;
541 
542 	/* set parity, bits per char, and stop bit */
543 	msm_write(port, mr, UART_MR2);
544 
545 	/* calculate and set hardware flow control */
546 	mr = msm_read(port, UART_MR1);
547 	mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
548 	if (termios->c_cflag & CRTSCTS) {
549 		mr |= UART_MR1_CTS_CTL;
550 		mr |= UART_MR1_RX_RDY_CTL;
551 	}
552 	msm_write(port, mr, UART_MR1);
553 
554 	/* Configure status bits to ignore based on termio flags. */
555 	port->read_status_mask = 0;
556 	if (termios->c_iflag & INPCK)
557 		port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
558 	if (termios->c_iflag & (BRKINT | PARMRK))
559 		port->read_status_mask |= UART_SR_RX_BREAK;
560 
561 	uart_update_timeout(port, termios->c_cflag, baud);
562 
563 	spin_unlock_irqrestore(&port->lock, flags);
564 }
565 
566 static const char *msm_type(struct uart_port *port)
567 {
568 	return "MSM";
569 }
570 
571 static void msm_release_port(struct uart_port *port)
572 {
573 	struct platform_device *pdev = to_platform_device(port->dev);
574 	struct msm_port *msm_port = UART_TO_MSM(port);
575 	struct resource *uart_resource;
576 	struct resource *gsbi_resource;
577 	resource_size_t size;
578 
579 	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
580 	if (unlikely(!uart_resource))
581 		return;
582 	size = resource_size(uart_resource);
583 
584 	release_mem_region(port->mapbase, size);
585 	iounmap(port->membase);
586 	port->membase = NULL;
587 
588 	if (msm_port->gsbi_base) {
589 		iowrite32(GSBI_PROTOCOL_IDLE, msm_port->gsbi_base +
590 			  GSBI_CONTROL);
591 
592 		gsbi_resource = platform_get_resource_byname(pdev,
593 							     IORESOURCE_MEM,
594 							     "gsbi_resource");
595 
596 		if (unlikely(!gsbi_resource))
597 			return;
598 
599 		size = resource_size(gsbi_resource);
600 		release_mem_region(gsbi_resource->start, size);
601 		iounmap(msm_port->gsbi_base);
602 		msm_port->gsbi_base = NULL;
603 	}
604 }
605 
606 static int msm_request_port(struct uart_port *port)
607 {
608 	struct msm_port *msm_port = UART_TO_MSM(port);
609 	struct platform_device *pdev = to_platform_device(port->dev);
610 	struct resource *uart_resource;
611 	struct resource *gsbi_resource;
612 	resource_size_t size;
613 	int ret;
614 
615 	uart_resource = platform_get_resource_byname(pdev, IORESOURCE_MEM,
616 						     "uart_resource");
617 	if (unlikely(!uart_resource))
618 		return -ENXIO;
619 
620 	size = resource_size(uart_resource);
621 
622 	if (!request_mem_region(port->mapbase, size, "msm_serial"))
623 		return -EBUSY;
624 
625 	port->membase = ioremap(port->mapbase, size);
626 	if (!port->membase) {
627 		ret = -EBUSY;
628 		goto fail_release_port;
629 	}
630 
631 	gsbi_resource = platform_get_resource_byname(pdev, IORESOURCE_MEM,
632 						     "gsbi_resource");
633 	/* Is this a GSBI-based port? */
634 	if (gsbi_resource) {
635 		size = resource_size(gsbi_resource);
636 
637 		if (!request_mem_region(gsbi_resource->start, size,
638 						 "msm_serial")) {
639 			ret = -EBUSY;
640 			goto fail_release_port;
641 		}
642 
643 		msm_port->gsbi_base = ioremap(gsbi_resource->start, size);
644 		if (!msm_port->gsbi_base) {
645 			ret = -EBUSY;
646 			goto fail_release_gsbi;
647 		}
648 	}
649 
650 	return 0;
651 
652 fail_release_gsbi:
653 	release_mem_region(gsbi_resource->start, size);
654 fail_release_port:
655 	release_mem_region(port->mapbase, size);
656 	return ret;
657 }
658 
659 static void msm_config_port(struct uart_port *port, int flags)
660 {
661 	struct msm_port *msm_port = UART_TO_MSM(port);
662 	int ret;
663 	if (flags & UART_CONFIG_TYPE) {
664 		port->type = PORT_MSM;
665 		ret = msm_request_port(port);
666 		if (ret)
667 			return;
668 	}
669 
670 	if (msm_port->is_uartdm)
671 		iowrite32(GSBI_PROTOCOL_UART, msm_port->gsbi_base +
672 			  GSBI_CONTROL);
673 }
674 
675 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
676 {
677 	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
678 		return -EINVAL;
679 	if (unlikely(port->irq != ser->irq))
680 		return -EINVAL;
681 	return 0;
682 }
683 
684 static void msm_power(struct uart_port *port, unsigned int state,
685 		      unsigned int oldstate)
686 {
687 	struct msm_port *msm_port = UART_TO_MSM(port);
688 
689 	switch (state) {
690 	case 0:
691 		clk_enable(msm_port->clk);
692 		if (!IS_ERR(msm_port->pclk))
693 			clk_enable(msm_port->pclk);
694 		break;
695 	case 3:
696 		clk_disable(msm_port->clk);
697 		if (!IS_ERR(msm_port->pclk))
698 			clk_disable(msm_port->pclk);
699 		break;
700 	default:
701 		printk(KERN_ERR "msm_serial: Unknown PM state %d\n", state);
702 	}
703 }
704 
705 static struct uart_ops msm_uart_pops = {
706 	.tx_empty = msm_tx_empty,
707 	.set_mctrl = msm_set_mctrl,
708 	.get_mctrl = msm_get_mctrl,
709 	.stop_tx = msm_stop_tx,
710 	.start_tx = msm_start_tx,
711 	.stop_rx = msm_stop_rx,
712 	.enable_ms = msm_enable_ms,
713 	.break_ctl = msm_break_ctl,
714 	.startup = msm_startup,
715 	.shutdown = msm_shutdown,
716 	.set_termios = msm_set_termios,
717 	.type = msm_type,
718 	.release_port = msm_release_port,
719 	.request_port = msm_request_port,
720 	.config_port = msm_config_port,
721 	.verify_port = msm_verify_port,
722 	.pm = msm_power,
723 };
724 
725 static struct msm_port msm_uart_ports[] = {
726 	{
727 		.uart = {
728 			.iotype = UPIO_MEM,
729 			.ops = &msm_uart_pops,
730 			.flags = UPF_BOOT_AUTOCONF,
731 			.fifosize = 64,
732 			.line = 0,
733 		},
734 	},
735 	{
736 		.uart = {
737 			.iotype = UPIO_MEM,
738 			.ops = &msm_uart_pops,
739 			.flags = UPF_BOOT_AUTOCONF,
740 			.fifosize = 64,
741 			.line = 1,
742 		},
743 	},
744 	{
745 		.uart = {
746 			.iotype = UPIO_MEM,
747 			.ops = &msm_uart_pops,
748 			.flags = UPF_BOOT_AUTOCONF,
749 			.fifosize = 64,
750 			.line = 2,
751 		},
752 	},
753 };
754 
755 #define UART_NR	ARRAY_SIZE(msm_uart_ports)
756 
757 static inline struct uart_port *get_port_from_line(unsigned int line)
758 {
759 	return &msm_uart_ports[line].uart;
760 }
761 
762 #ifdef CONFIG_SERIAL_MSM_CONSOLE
763 
764 static void msm_console_putchar(struct uart_port *port, int c)
765 {
766 	struct msm_port *msm_port = UART_TO_MSM(port);
767 
768 	if (msm_port->is_uartdm)
769 		reset_dm_count(port);
770 
771 	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
772 		;
773 	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
774 }
775 
776 static void msm_console_write(struct console *co, const char *s,
777 			      unsigned int count)
778 {
779 	struct uart_port *port;
780 	struct msm_port *msm_port;
781 
782 	BUG_ON(co->index < 0 || co->index >= UART_NR);
783 
784 	port = get_port_from_line(co->index);
785 	msm_port = UART_TO_MSM(port);
786 
787 	spin_lock(&port->lock);
788 	uart_console_write(port, s, count, msm_console_putchar);
789 	spin_unlock(&port->lock);
790 }
791 
792 static int __init msm_console_setup(struct console *co, char *options)
793 {
794 	struct uart_port *port;
795 	struct msm_port *msm_port;
796 	int baud, flow, bits, parity;
797 
798 	if (unlikely(co->index >= UART_NR || co->index < 0))
799 		return -ENXIO;
800 
801 	port = get_port_from_line(co->index);
802 	msm_port = UART_TO_MSM(port);
803 
804 	if (unlikely(!port->membase))
805 		return -ENXIO;
806 
807 	port->cons = co;
808 
809 	msm_init_clock(port);
810 
811 	if (options)
812 		uart_parse_options(options, &baud, &parity, &bits, &flow);
813 
814 	bits = 8;
815 	parity = 'n';
816 	flow = 'n';
817 	msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE,
818 		  UART_MR2);	/* 8N1 */
819 
820 	if (baud < 300 || baud > 115200)
821 		baud = 115200;
822 	msm_set_baud_rate(port, baud);
823 
824 	msm_reset(port);
825 
826 	if (msm_port->is_uartdm) {
827 		msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
828 		msm_write(port, UART_CR_TX_ENABLE, UART_CR);
829 	}
830 
831 	printk(KERN_INFO "msm_serial: console setup on port #%d\n", port->line);
832 
833 	return uart_set_options(port, co, baud, parity, bits, flow);
834 }
835 
836 static struct uart_driver msm_uart_driver;
837 
838 static struct console msm_console = {
839 	.name = "ttyMSM",
840 	.write = msm_console_write,
841 	.device = uart_console_device,
842 	.setup = msm_console_setup,
843 	.flags = CON_PRINTBUFFER,
844 	.index = -1,
845 	.data = &msm_uart_driver,
846 };
847 
848 #define MSM_CONSOLE	(&msm_console)
849 
850 #else
851 #define MSM_CONSOLE	NULL
852 #endif
853 
854 static struct uart_driver msm_uart_driver = {
855 	.owner = THIS_MODULE,
856 	.driver_name = "msm_serial",
857 	.dev_name = "ttyMSM",
858 	.nr = UART_NR,
859 	.cons = MSM_CONSOLE,
860 };
861 
862 static int __init msm_serial_probe(struct platform_device *pdev)
863 {
864 	struct msm_port *msm_port;
865 	struct resource *resource;
866 	struct uart_port *port;
867 	int irq;
868 
869 	if (unlikely(pdev->id < 0 || pdev->id >= UART_NR))
870 		return -ENXIO;
871 
872 	printk(KERN_INFO "msm_serial: detected port #%d\n", pdev->id);
873 
874 	port = get_port_from_line(pdev->id);
875 	port->dev = &pdev->dev;
876 	msm_port = UART_TO_MSM(port);
877 
878 	if (platform_get_resource_byname(pdev, IORESOURCE_MEM, "gsbi_resource"))
879 		msm_port->is_uartdm = 1;
880 	else
881 		msm_port->is_uartdm = 0;
882 
883 	if (msm_port->is_uartdm) {
884 		msm_port->clk = clk_get(&pdev->dev, "gsbi_uart_clk");
885 		msm_port->pclk = clk_get(&pdev->dev, "gsbi_pclk");
886 	} else {
887 		msm_port->clk = clk_get(&pdev->dev, "uart_clk");
888 		msm_port->pclk = ERR_PTR(-ENOENT);
889 	}
890 
891 	if (unlikely(IS_ERR(msm_port->clk) || (IS_ERR(msm_port->pclk) &&
892 					       msm_port->is_uartdm)))
893 			return PTR_ERR(msm_port->clk);
894 
895 	if (msm_port->is_uartdm)
896 		clk_set_rate(msm_port->clk, 7372800);
897 
898 	port->uartclk = clk_get_rate(msm_port->clk);
899 	printk(KERN_INFO "uartclk = %d\n", port->uartclk);
900 
901 
902 	resource = platform_get_resource_byname(pdev, IORESOURCE_MEM,
903 						     "uart_resource");
904 	if (unlikely(!resource))
905 		return -ENXIO;
906 	port->mapbase = resource->start;
907 
908 	irq = platform_get_irq(pdev, 0);
909 	if (unlikely(irq < 0))
910 		return -ENXIO;
911 	port->irq = irq;
912 
913 	platform_set_drvdata(pdev, port);
914 
915 	return uart_add_one_port(&msm_uart_driver, port);
916 }
917 
918 static int __devexit msm_serial_remove(struct platform_device *pdev)
919 {
920 	struct msm_port *msm_port = platform_get_drvdata(pdev);
921 
922 	clk_put(msm_port->clk);
923 
924 	return 0;
925 }
926 
927 static struct platform_driver msm_platform_driver = {
928 	.remove = msm_serial_remove,
929 	.driver = {
930 		.name = "msm_serial",
931 		.owner = THIS_MODULE,
932 	},
933 };
934 
935 static int __init msm_serial_init(void)
936 {
937 	int ret;
938 
939 	ret = uart_register_driver(&msm_uart_driver);
940 	if (unlikely(ret))
941 		return ret;
942 
943 	ret = platform_driver_probe(&msm_platform_driver, msm_serial_probe);
944 	if (unlikely(ret))
945 		uart_unregister_driver(&msm_uart_driver);
946 
947 	printk(KERN_INFO "msm_serial: driver initialized\n");
948 
949 	return ret;
950 }
951 
952 static void __exit msm_serial_exit(void)
953 {
954 #ifdef CONFIG_SERIAL_MSM_CONSOLE
955 	unregister_console(&msm_console);
956 #endif
957 	platform_driver_unregister(&msm_platform_driver);
958 	uart_unregister_driver(&msm_uart_driver);
959 }
960 
961 module_init(msm_serial_init);
962 module_exit(msm_serial_exit);
963 
964 MODULE_AUTHOR("Robert Love <rlove@google.com>");
965 MODULE_DESCRIPTION("Driver for msm7x serial device");
966 MODULE_LICENSE("GPL");
967