xref: /linux/drivers/tty/serial/omap-serial.c (revision c6bd5bcc4983f1a2d2f87a3769bf309482ee8c04)
1 /*
2  * Driver for OMAP-UART controller.
3  * Based on drivers/serial/8250.c
4  *
5  * Copyright (C) 2010 Texas Instruments.
6  *
7  * Authors:
8  *	Govindraj R	<govindraj.raja@ti.com>
9  *	Thara Gopinath	<thara@ti.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * Note: This driver is made separate from 8250 driver as we cannot
17  * over load 8250 driver with omap platform specific configuration for
18  * features like DMA, it makes easier to implement features like DMA and
19  * hardware flow control and software flow control configuration with
20  * this driver as required for the omap-platform.
21  */
22 
23 #if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24 #define SUPPORT_SYSRQ
25 #endif
26 
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/serial_reg.h>
31 #include <linux/delay.h>
32 #include <linux/slab.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/platform_device.h>
36 #include <linux/io.h>
37 #include <linux/clk.h>
38 #include <linux/serial_core.h>
39 #include <linux/irq.h>
40 #include <linux/pm_runtime.h>
41 #include <linux/of.h>
42 #include <linux/gpio.h>
43 #include <linux/pinctrl/consumer.h>
44 
45 #include <plat/omap-serial.h>
46 
47 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
48 
49 #define OMAP_UART_REV_42 0x0402
50 #define OMAP_UART_REV_46 0x0406
51 #define OMAP_UART_REV_52 0x0502
52 #define OMAP_UART_REV_63 0x0603
53 
54 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz*/
55 
56 /* SCR register bitmasks */
57 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
58 
59 /* FCR register bitmasks */
60 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)
61 #define OMAP_UART_FCR_TX_FIFO_TRIG_MASK			(0x3 << 4)
62 
63 /* MVR register bitmasks */
64 #define OMAP_UART_MVR_SCHEME_SHIFT	30
65 
66 #define OMAP_UART_LEGACY_MVR_MAJ_MASK	0xf0
67 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT	4
68 #define OMAP_UART_LEGACY_MVR_MIN_MASK	0x0f
69 
70 #define OMAP_UART_MVR_MAJ_MASK		0x700
71 #define OMAP_UART_MVR_MAJ_SHIFT		8
72 #define OMAP_UART_MVR_MIN_MASK		0x3f
73 
74 struct uart_omap_port {
75 	struct uart_port	port;
76 	struct uart_omap_dma	uart_dma;
77 	struct device		*dev;
78 
79 	unsigned char		ier;
80 	unsigned char		lcr;
81 	unsigned char		mcr;
82 	unsigned char		fcr;
83 	unsigned char		efr;
84 	unsigned char		dll;
85 	unsigned char		dlh;
86 	unsigned char		mdr1;
87 	unsigned char		scr;
88 
89 	int			use_dma;
90 	/*
91 	 * Some bits in registers are cleared on a read, so they must
92 	 * be saved whenever the register is read but the bits will not
93 	 * be immediately processed.
94 	 */
95 	unsigned int		lsr_break_flag;
96 	unsigned char		msr_saved_flags;
97 	char			name[20];
98 	unsigned long		port_activity;
99 	int			context_loss_cnt;
100 	u32			errata;
101 	u8			wakeups_enabled;
102 	unsigned int		irq_pending:1;
103 
104 	int			DTR_gpio;
105 	int			DTR_inverted;
106 	int			DTR_active;
107 
108 	struct pm_qos_request	pm_qos_request;
109 	u32			latency;
110 	u32			calc_latency;
111 	struct work_struct	qos_work;
112 	struct pinctrl		*pins;
113 };
114 
115 #define to_uart_omap_port(p)	((container_of((p), struct uart_omap_port, port)))
116 
117 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
118 
119 /* Forward declaration of functions */
120 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
121 
122 static struct workqueue_struct *serial_omap_uart_wq;
123 
124 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
125 {
126 	offset <<= up->port.regshift;
127 	return readw(up->port.membase + offset);
128 }
129 
130 static inline void serial_out(struct uart_omap_port *up, int offset, int value)
131 {
132 	offset <<= up->port.regshift;
133 	writew(value, up->port.membase + offset);
134 }
135 
136 static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
137 {
138 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
139 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
140 		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
141 	serial_out(up, UART_FCR, 0);
142 }
143 
144 static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
145 {
146 	struct omap_uart_port_info *pdata = up->dev->platform_data;
147 
148 	if (!pdata || !pdata->get_context_loss_count)
149 		return 0;
150 
151 	return pdata->get_context_loss_count(up->dev);
152 }
153 
154 static void serial_omap_set_forceidle(struct uart_omap_port *up)
155 {
156 	struct omap_uart_port_info *pdata = up->dev->platform_data;
157 
158 	if (!pdata || !pdata->set_forceidle)
159 		return;
160 
161 	pdata->set_forceidle(up->dev);
162 }
163 
164 static void serial_omap_set_noidle(struct uart_omap_port *up)
165 {
166 	struct omap_uart_port_info *pdata = up->dev->platform_data;
167 
168 	if (!pdata || !pdata->set_noidle)
169 		return;
170 
171 	pdata->set_noidle(up->dev);
172 }
173 
174 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
175 {
176 	struct omap_uart_port_info *pdata = up->dev->platform_data;
177 
178 	if (!pdata || !pdata->enable_wakeup)
179 		return;
180 
181 	pdata->enable_wakeup(up->dev, enable);
182 }
183 
184 /*
185  * serial_omap_get_divisor - calculate divisor value
186  * @port: uart port info
187  * @baud: baudrate for which divisor needs to be calculated.
188  *
189  * We have written our own function to get the divisor so as to support
190  * 13x mode. 3Mbps Baudrate as an different divisor.
191  * Reference OMAP TRM Chapter 17:
192  * Table 17-1. UART Mode Baud Rates, Divisor Values, and Error Rates
193  * referring to oversampling - divisor value
194  * baudrate 460,800 to 3,686,400 all have divisor 13
195  * except 3,000,000 which has divisor value 16
196  */
197 static unsigned int
198 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
199 {
200 	unsigned int divisor;
201 
202 	if (baud > OMAP_MODE13X_SPEED && baud != 3000000)
203 		divisor = 13;
204 	else
205 		divisor = 16;
206 	return port->uartclk/(baud * divisor);
207 }
208 
209 static void serial_omap_enable_ms(struct uart_port *port)
210 {
211 	struct uart_omap_port *up = to_uart_omap_port(port);
212 
213 	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);
214 
215 	pm_runtime_get_sync(up->dev);
216 	up->ier |= UART_IER_MSI;
217 	serial_out(up, UART_IER, up->ier);
218 	pm_runtime_mark_last_busy(up->dev);
219 	pm_runtime_put_autosuspend(up->dev);
220 }
221 
222 static void serial_omap_stop_tx(struct uart_port *port)
223 {
224 	struct uart_omap_port *up = to_uart_omap_port(port);
225 
226 	pm_runtime_get_sync(up->dev);
227 	if (up->ier & UART_IER_THRI) {
228 		up->ier &= ~UART_IER_THRI;
229 		serial_out(up, UART_IER, up->ier);
230 	}
231 
232 	serial_omap_set_forceidle(up);
233 
234 	pm_runtime_mark_last_busy(up->dev);
235 	pm_runtime_put_autosuspend(up->dev);
236 }
237 
238 static void serial_omap_stop_rx(struct uart_port *port)
239 {
240 	struct uart_omap_port *up = to_uart_omap_port(port);
241 
242 	pm_runtime_get_sync(up->dev);
243 	up->ier &= ~UART_IER_RLSI;
244 	up->port.read_status_mask &= ~UART_LSR_DR;
245 	serial_out(up, UART_IER, up->ier);
246 	pm_runtime_mark_last_busy(up->dev);
247 	pm_runtime_put_autosuspend(up->dev);
248 }
249 
250 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
251 {
252 	struct circ_buf *xmit = &up->port.state->xmit;
253 	int count;
254 
255 	if (!(lsr & UART_LSR_THRE))
256 		return;
257 
258 	if (up->port.x_char) {
259 		serial_out(up, UART_TX, up->port.x_char);
260 		up->port.icount.tx++;
261 		up->port.x_char = 0;
262 		return;
263 	}
264 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
265 		serial_omap_stop_tx(&up->port);
266 		return;
267 	}
268 	count = up->port.fifosize / 4;
269 	do {
270 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
271 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
272 		up->port.icount.tx++;
273 		if (uart_circ_empty(xmit))
274 			break;
275 	} while (--count > 0);
276 
277 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
278 		spin_unlock(&up->port.lock);
279 		uart_write_wakeup(&up->port);
280 		spin_lock(&up->port.lock);
281 	}
282 
283 	if (uart_circ_empty(xmit))
284 		serial_omap_stop_tx(&up->port);
285 }
286 
287 static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
288 {
289 	if (!(up->ier & UART_IER_THRI)) {
290 		up->ier |= UART_IER_THRI;
291 		serial_out(up, UART_IER, up->ier);
292 	}
293 }
294 
295 static void serial_omap_start_tx(struct uart_port *port)
296 {
297 	struct uart_omap_port *up = to_uart_omap_port(port);
298 
299 	pm_runtime_get_sync(up->dev);
300 	serial_omap_enable_ier_thri(up);
301 	serial_omap_set_noidle(up);
302 	pm_runtime_mark_last_busy(up->dev);
303 	pm_runtime_put_autosuspend(up->dev);
304 }
305 
306 static unsigned int check_modem_status(struct uart_omap_port *up)
307 {
308 	unsigned int status;
309 
310 	status = serial_in(up, UART_MSR);
311 	status |= up->msr_saved_flags;
312 	up->msr_saved_flags = 0;
313 	if ((status & UART_MSR_ANY_DELTA) == 0)
314 		return status;
315 
316 	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
317 	    up->port.state != NULL) {
318 		if (status & UART_MSR_TERI)
319 			up->port.icount.rng++;
320 		if (status & UART_MSR_DDSR)
321 			up->port.icount.dsr++;
322 		if (status & UART_MSR_DDCD)
323 			uart_handle_dcd_change
324 				(&up->port, status & UART_MSR_DCD);
325 		if (status & UART_MSR_DCTS)
326 			uart_handle_cts_change
327 				(&up->port, status & UART_MSR_CTS);
328 		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
329 	}
330 
331 	return status;
332 }
333 
334 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
335 {
336 	unsigned int flag;
337 	unsigned char ch = 0;
338 
339 	if (likely(lsr & UART_LSR_DR))
340 		ch = serial_in(up, UART_RX);
341 
342 	up->port.icount.rx++;
343 	flag = TTY_NORMAL;
344 
345 	if (lsr & UART_LSR_BI) {
346 		flag = TTY_BREAK;
347 		lsr &= ~(UART_LSR_FE | UART_LSR_PE);
348 		up->port.icount.brk++;
349 		/*
350 		 * We do the SysRQ and SAK checking
351 		 * here because otherwise the break
352 		 * may get masked by ignore_status_mask
353 		 * or read_status_mask.
354 		 */
355 		if (uart_handle_break(&up->port))
356 			return;
357 
358 	}
359 
360 	if (lsr & UART_LSR_PE) {
361 		flag = TTY_PARITY;
362 		up->port.icount.parity++;
363 	}
364 
365 	if (lsr & UART_LSR_FE) {
366 		flag = TTY_FRAME;
367 		up->port.icount.frame++;
368 	}
369 
370 	if (lsr & UART_LSR_OE)
371 		up->port.icount.overrun++;
372 
373 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
374 	if (up->port.line == up->port.cons->index) {
375 		/* Recover the break flag from console xmit */
376 		lsr |= up->lsr_break_flag;
377 	}
378 #endif
379 	uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag);
380 }
381 
382 static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
383 {
384 	unsigned char ch = 0;
385 	unsigned int flag;
386 
387 	if (!(lsr & UART_LSR_DR))
388 		return;
389 
390 	ch = serial_in(up, UART_RX);
391 	flag = TTY_NORMAL;
392 	up->port.icount.rx++;
393 
394 	if (uart_handle_sysrq_char(&up->port, ch))
395 		return;
396 
397 	uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
398 }
399 
400 /**
401  * serial_omap_irq() - This handles the interrupt from one port
402  * @irq: uart port irq number
403  * @dev_id: uart port info
404  */
405 static irqreturn_t serial_omap_irq(int irq, void *dev_id)
406 {
407 	struct uart_omap_port *up = dev_id;
408 	struct tty_struct *tty = up->port.state->port.tty;
409 	unsigned int iir, lsr;
410 	unsigned int type;
411 	irqreturn_t ret = IRQ_NONE;
412 	int max_count = 256;
413 
414 	spin_lock(&up->port.lock);
415 	pm_runtime_get_sync(up->dev);
416 
417 	do {
418 		iir = serial_in(up, UART_IIR);
419 		if (iir & UART_IIR_NO_INT)
420 			break;
421 
422 		ret = IRQ_HANDLED;
423 		lsr = serial_in(up, UART_LSR);
424 
425 		/* extract IRQ type from IIR register */
426 		type = iir & 0x3e;
427 
428 		switch (type) {
429 		case UART_IIR_MSI:
430 			check_modem_status(up);
431 			break;
432 		case UART_IIR_THRI:
433 			transmit_chars(up, lsr);
434 			break;
435 		case UART_IIR_RX_TIMEOUT:
436 			/* FALLTHROUGH */
437 		case UART_IIR_RDI:
438 			serial_omap_rdi(up, lsr);
439 			break;
440 		case UART_IIR_RLSI:
441 			serial_omap_rlsi(up, lsr);
442 			break;
443 		case UART_IIR_CTS_RTS_DSR:
444 			/* simply try again */
445 			break;
446 		case UART_IIR_XOFF:
447 			/* FALLTHROUGH */
448 		default:
449 			break;
450 		}
451 	} while (!(iir & UART_IIR_NO_INT) && max_count--);
452 
453 	spin_unlock(&up->port.lock);
454 
455 	tty_flip_buffer_push(tty);
456 
457 	pm_runtime_mark_last_busy(up->dev);
458 	pm_runtime_put_autosuspend(up->dev);
459 	up->port_activity = jiffies;
460 
461 	return ret;
462 }
463 
464 static unsigned int serial_omap_tx_empty(struct uart_port *port)
465 {
466 	struct uart_omap_port *up = to_uart_omap_port(port);
467 	unsigned long flags = 0;
468 	unsigned int ret = 0;
469 
470 	pm_runtime_get_sync(up->dev);
471 	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
472 	spin_lock_irqsave(&up->port.lock, flags);
473 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
474 	spin_unlock_irqrestore(&up->port.lock, flags);
475 	pm_runtime_mark_last_busy(up->dev);
476 	pm_runtime_put_autosuspend(up->dev);
477 	return ret;
478 }
479 
480 static unsigned int serial_omap_get_mctrl(struct uart_port *port)
481 {
482 	struct uart_omap_port *up = to_uart_omap_port(port);
483 	unsigned int status;
484 	unsigned int ret = 0;
485 
486 	pm_runtime_get_sync(up->dev);
487 	status = check_modem_status(up);
488 	pm_runtime_mark_last_busy(up->dev);
489 	pm_runtime_put_autosuspend(up->dev);
490 
491 	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);
492 
493 	if (status & UART_MSR_DCD)
494 		ret |= TIOCM_CAR;
495 	if (status & UART_MSR_RI)
496 		ret |= TIOCM_RNG;
497 	if (status & UART_MSR_DSR)
498 		ret |= TIOCM_DSR;
499 	if (status & UART_MSR_CTS)
500 		ret |= TIOCM_CTS;
501 	return ret;
502 }
503 
504 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
505 {
506 	struct uart_omap_port *up = to_uart_omap_port(port);
507 	unsigned char mcr = 0;
508 
509 	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
510 	if (mctrl & TIOCM_RTS)
511 		mcr |= UART_MCR_RTS;
512 	if (mctrl & TIOCM_DTR)
513 		mcr |= UART_MCR_DTR;
514 	if (mctrl & TIOCM_OUT1)
515 		mcr |= UART_MCR_OUT1;
516 	if (mctrl & TIOCM_OUT2)
517 		mcr |= UART_MCR_OUT2;
518 	if (mctrl & TIOCM_LOOP)
519 		mcr |= UART_MCR_LOOP;
520 
521 	pm_runtime_get_sync(up->dev);
522 	up->mcr = serial_in(up, UART_MCR);
523 	up->mcr |= mcr;
524 	serial_out(up, UART_MCR, up->mcr);
525 	pm_runtime_mark_last_busy(up->dev);
526 	pm_runtime_put_autosuspend(up->dev);
527 
528 	if (gpio_is_valid(up->DTR_gpio) &&
529 	    !!(mctrl & TIOCM_DTR) != up->DTR_active) {
530 		up->DTR_active = !up->DTR_active;
531 		if (gpio_cansleep(up->DTR_gpio))
532 			schedule_work(&up->qos_work);
533 		else
534 			gpio_set_value(up->DTR_gpio,
535 				       up->DTR_active != up->DTR_inverted);
536 	}
537 }
538 
539 static void serial_omap_break_ctl(struct uart_port *port, int break_state)
540 {
541 	struct uart_omap_port *up = to_uart_omap_port(port);
542 	unsigned long flags = 0;
543 
544 	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
545 	pm_runtime_get_sync(up->dev);
546 	spin_lock_irqsave(&up->port.lock, flags);
547 	if (break_state == -1)
548 		up->lcr |= UART_LCR_SBC;
549 	else
550 		up->lcr &= ~UART_LCR_SBC;
551 	serial_out(up, UART_LCR, up->lcr);
552 	spin_unlock_irqrestore(&up->port.lock, flags);
553 	pm_runtime_mark_last_busy(up->dev);
554 	pm_runtime_put_autosuspend(up->dev);
555 }
556 
557 static int serial_omap_startup(struct uart_port *port)
558 {
559 	struct uart_omap_port *up = to_uart_omap_port(port);
560 	unsigned long flags = 0;
561 	int retval;
562 
563 	/*
564 	 * Allocate the IRQ
565 	 */
566 	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
567 				up->name, up);
568 	if (retval)
569 		return retval;
570 
571 	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
572 
573 	pm_runtime_get_sync(up->dev);
574 	/*
575 	 * Clear the FIFO buffers and disable them.
576 	 * (they will be reenabled in set_termios())
577 	 */
578 	serial_omap_clear_fifos(up);
579 	/* For Hardware flow control */
580 	serial_out(up, UART_MCR, UART_MCR_RTS);
581 
582 	/*
583 	 * Clear the interrupt registers.
584 	 */
585 	(void) serial_in(up, UART_LSR);
586 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
587 		(void) serial_in(up, UART_RX);
588 	(void) serial_in(up, UART_IIR);
589 	(void) serial_in(up, UART_MSR);
590 
591 	/*
592 	 * Now, initialize the UART
593 	 */
594 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
595 	spin_lock_irqsave(&up->port.lock, flags);
596 	/*
597 	 * Most PC uarts need OUT2 raised to enable interrupts.
598 	 */
599 	up->port.mctrl |= TIOCM_OUT2;
600 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
601 	spin_unlock_irqrestore(&up->port.lock, flags);
602 
603 	up->msr_saved_flags = 0;
604 	/*
605 	 * Finally, enable interrupts. Note: Modem status interrupts
606 	 * are set via set_termios(), which will be occurring imminently
607 	 * anyway, so we don't enable them here.
608 	 */
609 	up->ier = UART_IER_RLSI | UART_IER_RDI;
610 	serial_out(up, UART_IER, up->ier);
611 
612 	/* Enable module level wake up */
613 	serial_out(up, UART_OMAP_WER, OMAP_UART_WER_MOD_WKUP);
614 
615 	pm_runtime_mark_last_busy(up->dev);
616 	pm_runtime_put_autosuspend(up->dev);
617 	up->port_activity = jiffies;
618 	return 0;
619 }
620 
621 static void serial_omap_shutdown(struct uart_port *port)
622 {
623 	struct uart_omap_port *up = to_uart_omap_port(port);
624 	unsigned long flags = 0;
625 
626 	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);
627 
628 	pm_runtime_get_sync(up->dev);
629 	/*
630 	 * Disable interrupts from this port
631 	 */
632 	up->ier = 0;
633 	serial_out(up, UART_IER, 0);
634 
635 	spin_lock_irqsave(&up->port.lock, flags);
636 	up->port.mctrl &= ~TIOCM_OUT2;
637 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
638 	spin_unlock_irqrestore(&up->port.lock, flags);
639 
640 	/*
641 	 * Disable break condition and FIFOs
642 	 */
643 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
644 	serial_omap_clear_fifos(up);
645 
646 	/*
647 	 * Read data port to reset things, and then free the irq
648 	 */
649 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
650 		(void) serial_in(up, UART_RX);
651 
652 	pm_runtime_mark_last_busy(up->dev);
653 	pm_runtime_put_autosuspend(up->dev);
654 	free_irq(up->port.irq, up);
655 }
656 
657 static inline void
658 serial_omap_configure_xonxoff
659 		(struct uart_omap_port *up, struct ktermios *termios)
660 {
661 	up->lcr = serial_in(up, UART_LCR);
662 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
663 	up->efr = serial_in(up, UART_EFR);
664 	serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);
665 
666 	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
667 	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
668 
669 	/* clear SW control mode bits */
670 	up->efr &= OMAP_UART_SW_CLR;
671 
672 	/*
673 	 * IXON Flag:
674 	 * Enable XON/XOFF flow control on output.
675 	 * Transmit XON1, XOFF1
676 	 */
677 	if (termios->c_iflag & IXON)
678 		up->efr |= OMAP_UART_SW_TX;
679 
680 	/*
681 	 * IXOFF Flag:
682 	 * Enable XON/XOFF flow control on input.
683 	 * Receiver compares XON1, XOFF1.
684 	 */
685 	if (termios->c_iflag & IXOFF)
686 		up->efr |= OMAP_UART_SW_RX;
687 
688 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
689 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
690 
691 	up->mcr = serial_in(up, UART_MCR);
692 
693 	/*
694 	 * IXANY Flag:
695 	 * Enable any character to restart output.
696 	 * Operation resumes after receiving any
697 	 * character after recognition of the XOFF character
698 	 */
699 	if (termios->c_iflag & IXANY)
700 		up->mcr |= UART_MCR_XONANY;
701 
702 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
703 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
704 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
705 
706 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
707 
708 	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
709 	serial_out(up, UART_LCR, up->lcr);
710 }
711 
712 static void serial_omap_uart_qos_work(struct work_struct *work)
713 {
714 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
715 						qos_work);
716 
717 	pm_qos_update_request(&up->pm_qos_request, up->latency);
718 	if (gpio_is_valid(up->DTR_gpio))
719 		gpio_set_value_cansleep(up->DTR_gpio,
720 					up->DTR_active != up->DTR_inverted);
721 }
722 
723 static void
724 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
725 			struct ktermios *old)
726 {
727 	struct uart_omap_port *up = to_uart_omap_port(port);
728 	unsigned char cval = 0;
729 	unsigned char efr = 0;
730 	unsigned long flags = 0;
731 	unsigned int baud, quot;
732 
733 	switch (termios->c_cflag & CSIZE) {
734 	case CS5:
735 		cval = UART_LCR_WLEN5;
736 		break;
737 	case CS6:
738 		cval = UART_LCR_WLEN6;
739 		break;
740 	case CS7:
741 		cval = UART_LCR_WLEN7;
742 		break;
743 	default:
744 	case CS8:
745 		cval = UART_LCR_WLEN8;
746 		break;
747 	}
748 
749 	if (termios->c_cflag & CSTOPB)
750 		cval |= UART_LCR_STOP;
751 	if (termios->c_cflag & PARENB)
752 		cval |= UART_LCR_PARITY;
753 	if (!(termios->c_cflag & PARODD))
754 		cval |= UART_LCR_EPAR;
755 
756 	/*
757 	 * Ask the core to calculate the divisor for us.
758 	 */
759 
760 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
761 	quot = serial_omap_get_divisor(port, baud);
762 
763 	/* calculate wakeup latency constraint */
764 	up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
765 	up->latency = up->calc_latency;
766 	schedule_work(&up->qos_work);
767 
768 	up->dll = quot & 0xff;
769 	up->dlh = quot >> 8;
770 	up->mdr1 = UART_OMAP_MDR1_DISABLE;
771 
772 	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
773 			UART_FCR_ENABLE_FIFO;
774 
775 	/*
776 	 * Ok, we're now changing the port state. Do it with
777 	 * interrupts disabled.
778 	 */
779 	pm_runtime_get_sync(up->dev);
780 	spin_lock_irqsave(&up->port.lock, flags);
781 
782 	/*
783 	 * Update the per-port timeout.
784 	 */
785 	uart_update_timeout(port, termios->c_cflag, baud);
786 
787 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
788 	if (termios->c_iflag & INPCK)
789 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
790 	if (termios->c_iflag & (BRKINT | PARMRK))
791 		up->port.read_status_mask |= UART_LSR_BI;
792 
793 	/*
794 	 * Characters to ignore
795 	 */
796 	up->port.ignore_status_mask = 0;
797 	if (termios->c_iflag & IGNPAR)
798 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
799 	if (termios->c_iflag & IGNBRK) {
800 		up->port.ignore_status_mask |= UART_LSR_BI;
801 		/*
802 		 * If we're ignoring parity and break indicators,
803 		 * ignore overruns too (for real raw support).
804 		 */
805 		if (termios->c_iflag & IGNPAR)
806 			up->port.ignore_status_mask |= UART_LSR_OE;
807 	}
808 
809 	/*
810 	 * ignore all characters if CREAD is not set
811 	 */
812 	if ((termios->c_cflag & CREAD) == 0)
813 		up->port.ignore_status_mask |= UART_LSR_DR;
814 
815 	/*
816 	 * Modem status interrupts
817 	 */
818 	up->ier &= ~UART_IER_MSI;
819 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
820 		up->ier |= UART_IER_MSI;
821 	serial_out(up, UART_IER, up->ier);
822 	serial_out(up, UART_LCR, cval);		/* reset DLAB */
823 	up->lcr = cval;
824 	up->scr = OMAP_UART_SCR_TX_EMPTY;
825 
826 	/* FIFOs and DMA Settings */
827 
828 	/* FCR can be changed only when the
829 	 * baud clock is not running
830 	 * DLL_REG and DLH_REG set to 0.
831 	 */
832 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
833 	serial_out(up, UART_DLL, 0);
834 	serial_out(up, UART_DLM, 0);
835 	serial_out(up, UART_LCR, 0);
836 
837 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
838 
839 	up->efr = serial_in(up, UART_EFR);
840 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
841 
842 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
843 	up->mcr = serial_in(up, UART_MCR);
844 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
845 	/* FIFO ENABLE, DMA MODE */
846 
847 	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
848 
849 	/* Set receive FIFO threshold to 16 characters and
850 	 * transmit FIFO threshold to 16 spaces
851 	 */
852 	up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
853 	up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
854 	up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 |
855 		UART_FCR_ENABLE_FIFO;
856 
857 	serial_out(up, UART_FCR, up->fcr);
858 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
859 
860 	serial_out(up, UART_OMAP_SCR, up->scr);
861 
862 	serial_out(up, UART_EFR, up->efr);
863 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
864 	serial_out(up, UART_MCR, up->mcr);
865 
866 	/* Protocol, Baud Rate, and Interrupt Settings */
867 
868 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
869 		serial_omap_mdr1_errataset(up, up->mdr1);
870 	else
871 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
872 
873 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
874 
875 	up->efr = serial_in(up, UART_EFR);
876 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
877 
878 	serial_out(up, UART_LCR, 0);
879 	serial_out(up, UART_IER, 0);
880 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
881 
882 	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
883 	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */
884 
885 	serial_out(up, UART_LCR, 0);
886 	serial_out(up, UART_IER, up->ier);
887 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
888 
889 	serial_out(up, UART_EFR, up->efr);
890 	serial_out(up, UART_LCR, cval);
891 
892 	if (baud > 230400 && baud != 3000000)
893 		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
894 	else
895 		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
896 
897 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
898 		serial_omap_mdr1_errataset(up, up->mdr1);
899 	else
900 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
901 
902 	/* Hardware Flow Control Configuration */
903 
904 	if (termios->c_cflag & CRTSCTS) {
905 		efr |= (UART_EFR_CTS | UART_EFR_RTS);
906 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
907 
908 		up->mcr = serial_in(up, UART_MCR);
909 		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
910 
911 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
912 		up->efr = serial_in(up, UART_EFR);
913 		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
914 
915 		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
916 		serial_out(up, UART_EFR, efr); /* Enable AUTORTS and AUTOCTS */
917 		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
918 		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
919 		serial_out(up, UART_LCR, cval);
920 	}
921 
922 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
923 	/* Software Flow Control Configuration */
924 	serial_omap_configure_xonxoff(up, termios);
925 
926 	spin_unlock_irqrestore(&up->port.lock, flags);
927 	pm_runtime_mark_last_busy(up->dev);
928 	pm_runtime_put_autosuspend(up->dev);
929 	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
930 }
931 
932 static int serial_omap_set_wake(struct uart_port *port, unsigned int state)
933 {
934 	struct uart_omap_port *up = to_uart_omap_port(port);
935 
936 	serial_omap_enable_wakeup(up, state);
937 
938 	return 0;
939 }
940 
941 static void
942 serial_omap_pm(struct uart_port *port, unsigned int state,
943 	       unsigned int oldstate)
944 {
945 	struct uart_omap_port *up = to_uart_omap_port(port);
946 	unsigned char efr;
947 
948 	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);
949 
950 	pm_runtime_get_sync(up->dev);
951 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
952 	efr = serial_in(up, UART_EFR);
953 	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
954 	serial_out(up, UART_LCR, 0);
955 
956 	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
957 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
958 	serial_out(up, UART_EFR, efr);
959 	serial_out(up, UART_LCR, 0);
960 
961 	if (!device_may_wakeup(up->dev)) {
962 		if (!state)
963 			pm_runtime_forbid(up->dev);
964 		else
965 			pm_runtime_allow(up->dev);
966 	}
967 
968 	pm_runtime_mark_last_busy(up->dev);
969 	pm_runtime_put_autosuspend(up->dev);
970 }
971 
972 static void serial_omap_release_port(struct uart_port *port)
973 {
974 	dev_dbg(port->dev, "serial_omap_release_port+\n");
975 }
976 
977 static int serial_omap_request_port(struct uart_port *port)
978 {
979 	dev_dbg(port->dev, "serial_omap_request_port+\n");
980 	return 0;
981 }
982 
983 static void serial_omap_config_port(struct uart_port *port, int flags)
984 {
985 	struct uart_omap_port *up = to_uart_omap_port(port);
986 
987 	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
988 							up->port.line);
989 	up->port.type = PORT_OMAP;
990 }
991 
992 static int
993 serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
994 {
995 	/* we don't want the core code to modify any port params */
996 	dev_dbg(port->dev, "serial_omap_verify_port+\n");
997 	return -EINVAL;
998 }
999 
1000 static const char *
1001 serial_omap_type(struct uart_port *port)
1002 {
1003 	struct uart_omap_port *up = to_uart_omap_port(port);
1004 
1005 	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
1006 	return up->name;
1007 }
1008 
1009 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1010 
1011 static inline void wait_for_xmitr(struct uart_omap_port *up)
1012 {
1013 	unsigned int status, tmout = 10000;
1014 
1015 	/* Wait up to 10ms for the character(s) to be sent. */
1016 	do {
1017 		status = serial_in(up, UART_LSR);
1018 
1019 		if (status & UART_LSR_BI)
1020 			up->lsr_break_flag = UART_LSR_BI;
1021 
1022 		if (--tmout == 0)
1023 			break;
1024 		udelay(1);
1025 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
1026 
1027 	/* Wait up to 1s for flow control if necessary */
1028 	if (up->port.flags & UPF_CONS_FLOW) {
1029 		tmout = 1000000;
1030 		for (tmout = 1000000; tmout; tmout--) {
1031 			unsigned int msr = serial_in(up, UART_MSR);
1032 
1033 			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1034 			if (msr & UART_MSR_CTS)
1035 				break;
1036 
1037 			udelay(1);
1038 		}
1039 	}
1040 }
1041 
1042 #ifdef CONFIG_CONSOLE_POLL
1043 
1044 static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
1045 {
1046 	struct uart_omap_port *up = to_uart_omap_port(port);
1047 
1048 	pm_runtime_get_sync(up->dev);
1049 	wait_for_xmitr(up);
1050 	serial_out(up, UART_TX, ch);
1051 	pm_runtime_mark_last_busy(up->dev);
1052 	pm_runtime_put_autosuspend(up->dev);
1053 }
1054 
1055 static int serial_omap_poll_get_char(struct uart_port *port)
1056 {
1057 	struct uart_omap_port *up = to_uart_omap_port(port);
1058 	unsigned int status;
1059 
1060 	pm_runtime_get_sync(up->dev);
1061 	status = serial_in(up, UART_LSR);
1062 	if (!(status & UART_LSR_DR)) {
1063 		status = NO_POLL_CHAR;
1064 		goto out;
1065 	}
1066 
1067 	status = serial_in(up, UART_RX);
1068 
1069 out:
1070 	pm_runtime_mark_last_busy(up->dev);
1071 	pm_runtime_put_autosuspend(up->dev);
1072 
1073 	return status;
1074 }
1075 
1076 #endif /* CONFIG_CONSOLE_POLL */
1077 
1078 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
1079 
1080 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
1081 
1082 static struct uart_driver serial_omap_reg;
1083 
1084 static void serial_omap_console_putchar(struct uart_port *port, int ch)
1085 {
1086 	struct uart_omap_port *up = to_uart_omap_port(port);
1087 
1088 	wait_for_xmitr(up);
1089 	serial_out(up, UART_TX, ch);
1090 }
1091 
1092 static void
1093 serial_omap_console_write(struct console *co, const char *s,
1094 		unsigned int count)
1095 {
1096 	struct uart_omap_port *up = serial_omap_console_ports[co->index];
1097 	unsigned long flags;
1098 	unsigned int ier;
1099 	int locked = 1;
1100 
1101 	pm_runtime_get_sync(up->dev);
1102 
1103 	local_irq_save(flags);
1104 	if (up->port.sysrq)
1105 		locked = 0;
1106 	else if (oops_in_progress)
1107 		locked = spin_trylock(&up->port.lock);
1108 	else
1109 		spin_lock(&up->port.lock);
1110 
1111 	/*
1112 	 * First save the IER then disable the interrupts
1113 	 */
1114 	ier = serial_in(up, UART_IER);
1115 	serial_out(up, UART_IER, 0);
1116 
1117 	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
1118 
1119 	/*
1120 	 * Finally, wait for transmitter to become empty
1121 	 * and restore the IER
1122 	 */
1123 	wait_for_xmitr(up);
1124 	serial_out(up, UART_IER, ier);
1125 	/*
1126 	 * The receive handling will happen properly because the
1127 	 * receive ready bit will still be set; it is not cleared
1128 	 * on read.  However, modem control will not, we must
1129 	 * call it if we have saved something in the saved flags
1130 	 * while processing with interrupts off.
1131 	 */
1132 	if (up->msr_saved_flags)
1133 		check_modem_status(up);
1134 
1135 	pm_runtime_mark_last_busy(up->dev);
1136 	pm_runtime_put_autosuspend(up->dev);
1137 	if (locked)
1138 		spin_unlock(&up->port.lock);
1139 	local_irq_restore(flags);
1140 }
1141 
1142 static int __init
1143 serial_omap_console_setup(struct console *co, char *options)
1144 {
1145 	struct uart_omap_port *up;
1146 	int baud = 115200;
1147 	int bits = 8;
1148 	int parity = 'n';
1149 	int flow = 'n';
1150 
1151 	if (serial_omap_console_ports[co->index] == NULL)
1152 		return -ENODEV;
1153 	up = serial_omap_console_ports[co->index];
1154 
1155 	if (options)
1156 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1157 
1158 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
1159 }
1160 
1161 static struct console serial_omap_console = {
1162 	.name		= OMAP_SERIAL_NAME,
1163 	.write		= serial_omap_console_write,
1164 	.device		= uart_console_device,
1165 	.setup		= serial_omap_console_setup,
1166 	.flags		= CON_PRINTBUFFER,
1167 	.index		= -1,
1168 	.data		= &serial_omap_reg,
1169 };
1170 
1171 static void serial_omap_add_console_port(struct uart_omap_port *up)
1172 {
1173 	serial_omap_console_ports[up->port.line] = up;
1174 }
1175 
1176 #define OMAP_CONSOLE	(&serial_omap_console)
1177 
1178 #else
1179 
1180 #define OMAP_CONSOLE	NULL
1181 
1182 static inline void serial_omap_add_console_port(struct uart_omap_port *up)
1183 {}
1184 
1185 #endif
1186 
1187 static struct uart_ops serial_omap_pops = {
1188 	.tx_empty	= serial_omap_tx_empty,
1189 	.set_mctrl	= serial_omap_set_mctrl,
1190 	.get_mctrl	= serial_omap_get_mctrl,
1191 	.stop_tx	= serial_omap_stop_tx,
1192 	.start_tx	= serial_omap_start_tx,
1193 	.stop_rx	= serial_omap_stop_rx,
1194 	.enable_ms	= serial_omap_enable_ms,
1195 	.break_ctl	= serial_omap_break_ctl,
1196 	.startup	= serial_omap_startup,
1197 	.shutdown	= serial_omap_shutdown,
1198 	.set_termios	= serial_omap_set_termios,
1199 	.pm		= serial_omap_pm,
1200 	.set_wake	= serial_omap_set_wake,
1201 	.type		= serial_omap_type,
1202 	.release_port	= serial_omap_release_port,
1203 	.request_port	= serial_omap_request_port,
1204 	.config_port	= serial_omap_config_port,
1205 	.verify_port	= serial_omap_verify_port,
1206 #ifdef CONFIG_CONSOLE_POLL
1207 	.poll_put_char  = serial_omap_poll_put_char,
1208 	.poll_get_char  = serial_omap_poll_get_char,
1209 #endif
1210 };
1211 
1212 static struct uart_driver serial_omap_reg = {
1213 	.owner		= THIS_MODULE,
1214 	.driver_name	= "OMAP-SERIAL",
1215 	.dev_name	= OMAP_SERIAL_NAME,
1216 	.nr		= OMAP_MAX_HSUART_PORTS,
1217 	.cons		= OMAP_CONSOLE,
1218 };
1219 
1220 #ifdef CONFIG_PM_SLEEP
1221 static int serial_omap_suspend(struct device *dev)
1222 {
1223 	struct uart_omap_port *up = dev_get_drvdata(dev);
1224 
1225 	uart_suspend_port(&serial_omap_reg, &up->port);
1226 	flush_work(&up->qos_work);
1227 
1228 	return 0;
1229 }
1230 
1231 static int serial_omap_resume(struct device *dev)
1232 {
1233 	struct uart_omap_port *up = dev_get_drvdata(dev);
1234 
1235 	uart_resume_port(&serial_omap_reg, &up->port);
1236 
1237 	return 0;
1238 }
1239 #endif
1240 
1241 static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
1242 {
1243 	u32 mvr, scheme;
1244 	u16 revision, major, minor;
1245 
1246 	mvr = serial_in(up, UART_OMAP_MVER);
1247 
1248 	/* Check revision register scheme */
1249 	scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
1250 
1251 	switch (scheme) {
1252 	case 0: /* Legacy Scheme: OMAP2/3 */
1253 		/* MINOR_REV[0:4], MAJOR_REV[4:7] */
1254 		major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
1255 					OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
1256 		minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
1257 		break;
1258 	case 1:
1259 		/* New Scheme: OMAP4+ */
1260 		/* MINOR_REV[0:5], MAJOR_REV[8:10] */
1261 		major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
1262 					OMAP_UART_MVR_MAJ_SHIFT;
1263 		minor = (mvr & OMAP_UART_MVR_MIN_MASK);
1264 		break;
1265 	default:
1266 		dev_warn(up->dev,
1267 			"Unknown %s revision, defaulting to highest\n",
1268 			up->name);
1269 		/* highest possible revision */
1270 		major = 0xff;
1271 		minor = 0xff;
1272 	}
1273 
1274 	/* normalize revision for the driver */
1275 	revision = UART_BUILD_REVISION(major, minor);
1276 
1277 	switch (revision) {
1278 	case OMAP_UART_REV_46:
1279 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1280 				UART_ERRATA_i291_DMA_FORCEIDLE);
1281 		break;
1282 	case OMAP_UART_REV_52:
1283 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1284 				UART_ERRATA_i291_DMA_FORCEIDLE);
1285 		break;
1286 	case OMAP_UART_REV_63:
1287 		up->errata |= UART_ERRATA_i202_MDR1_ACCESS;
1288 		break;
1289 	default:
1290 		break;
1291 	}
1292 }
1293 
1294 static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
1295 {
1296 	struct omap_uart_port_info *omap_up_info;
1297 
1298 	omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
1299 	if (!omap_up_info)
1300 		return NULL; /* out of memory */
1301 
1302 	of_property_read_u32(dev->of_node, "clock-frequency",
1303 					 &omap_up_info->uartclk);
1304 	return omap_up_info;
1305 }
1306 
1307 static int serial_omap_probe(struct platform_device *pdev)
1308 {
1309 	struct uart_omap_port	*up;
1310 	struct resource		*mem, *irq;
1311 	struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data;
1312 	int ret;
1313 
1314 	if (pdev->dev.of_node)
1315 		omap_up_info = of_get_uart_port_info(&pdev->dev);
1316 
1317 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1318 	if (!mem) {
1319 		dev_err(&pdev->dev, "no mem resource?\n");
1320 		return -ENODEV;
1321 	}
1322 
1323 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1324 	if (!irq) {
1325 		dev_err(&pdev->dev, "no irq resource?\n");
1326 		return -ENODEV;
1327 	}
1328 
1329 	if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
1330 				pdev->dev.driver->name)) {
1331 		dev_err(&pdev->dev, "memory region already claimed\n");
1332 		return -EBUSY;
1333 	}
1334 
1335 	if (gpio_is_valid(omap_up_info->DTR_gpio) &&
1336 	    omap_up_info->DTR_present) {
1337 		ret = gpio_request(omap_up_info->DTR_gpio, "omap-serial");
1338 		if (ret < 0)
1339 			return ret;
1340 		ret = gpio_direction_output(omap_up_info->DTR_gpio,
1341 					    omap_up_info->DTR_inverted);
1342 		if (ret < 0)
1343 			return ret;
1344 	}
1345 
1346 	up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
1347 	if (!up)
1348 		return -ENOMEM;
1349 
1350 	if (gpio_is_valid(omap_up_info->DTR_gpio) &&
1351 	    omap_up_info->DTR_present) {
1352 		up->DTR_gpio = omap_up_info->DTR_gpio;
1353 		up->DTR_inverted = omap_up_info->DTR_inverted;
1354 	} else
1355 		up->DTR_gpio = -EINVAL;
1356 	up->DTR_active = 0;
1357 
1358 	up->dev = &pdev->dev;
1359 	up->port.dev = &pdev->dev;
1360 	up->port.type = PORT_OMAP;
1361 	up->port.iotype = UPIO_MEM;
1362 	up->port.irq = irq->start;
1363 
1364 	up->port.regshift = 2;
1365 	up->port.fifosize = 64;
1366 	up->port.ops = &serial_omap_pops;
1367 
1368 	if (pdev->dev.of_node)
1369 		up->port.line = of_alias_get_id(pdev->dev.of_node, "serial");
1370 	else
1371 		up->port.line = pdev->id;
1372 
1373 	if (up->port.line < 0) {
1374 		dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
1375 								up->port.line);
1376 		ret = -ENODEV;
1377 		goto err_port_line;
1378 	}
1379 
1380 	up->pins = devm_pinctrl_get_select_default(&pdev->dev);
1381 	if (IS_ERR(up->pins)) {
1382 		dev_warn(&pdev->dev, "did not get pins for uart%i error: %li\n",
1383 			 up->port.line, PTR_ERR(up->pins));
1384 		up->pins = NULL;
1385 	}
1386 
1387 	sprintf(up->name, "OMAP UART%d", up->port.line);
1388 	up->port.mapbase = mem->start;
1389 	up->port.membase = devm_ioremap(&pdev->dev, mem->start,
1390 						resource_size(mem));
1391 	if (!up->port.membase) {
1392 		dev_err(&pdev->dev, "can't ioremap UART\n");
1393 		ret = -ENOMEM;
1394 		goto err_ioremap;
1395 	}
1396 
1397 	up->port.flags = omap_up_info->flags;
1398 	up->port.uartclk = omap_up_info->uartclk;
1399 	if (!up->port.uartclk) {
1400 		up->port.uartclk = DEFAULT_CLK_SPEED;
1401 		dev_warn(&pdev->dev, "No clock speed specified: using default:"
1402 						"%d\n", DEFAULT_CLK_SPEED);
1403 	}
1404 
1405 	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1406 	up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1407 	pm_qos_add_request(&up->pm_qos_request,
1408 		PM_QOS_CPU_DMA_LATENCY, up->latency);
1409 	serial_omap_uart_wq = create_singlethread_workqueue(up->name);
1410 	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
1411 
1412 	platform_set_drvdata(pdev, up);
1413 	pm_runtime_enable(&pdev->dev);
1414 	pm_runtime_use_autosuspend(&pdev->dev);
1415 	pm_runtime_set_autosuspend_delay(&pdev->dev,
1416 			omap_up_info->autosuspend_timeout);
1417 
1418 	pm_runtime_irq_safe(&pdev->dev);
1419 	pm_runtime_get_sync(&pdev->dev);
1420 
1421 	omap_serial_fill_features_erratas(up);
1422 
1423 	ui[up->port.line] = up;
1424 	serial_omap_add_console_port(up);
1425 
1426 	ret = uart_add_one_port(&serial_omap_reg, &up->port);
1427 	if (ret != 0)
1428 		goto err_add_port;
1429 
1430 	pm_runtime_mark_last_busy(up->dev);
1431 	pm_runtime_put_autosuspend(up->dev);
1432 	return 0;
1433 
1434 err_add_port:
1435 	pm_runtime_put(&pdev->dev);
1436 	pm_runtime_disable(&pdev->dev);
1437 err_ioremap:
1438 err_port_line:
1439 	dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
1440 				pdev->id, __func__, ret);
1441 	return ret;
1442 }
1443 
1444 static int serial_omap_remove(struct platform_device *dev)
1445 {
1446 	struct uart_omap_port *up = platform_get_drvdata(dev);
1447 
1448 	pm_runtime_put_sync(up->dev);
1449 	pm_runtime_disable(up->dev);
1450 	uart_remove_one_port(&serial_omap_reg, &up->port);
1451 	pm_qos_remove_request(&up->pm_qos_request);
1452 
1453 	return 0;
1454 }
1455 
1456 /*
1457  * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
1458  * The access to uart register after MDR1 Access
1459  * causes UART to corrupt data.
1460  *
1461  * Need a delay =
1462  * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
1463  * give 10 times as much
1464  */
1465 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
1466 {
1467 	u8 timeout = 255;
1468 
1469 	serial_out(up, UART_OMAP_MDR1, mdr1);
1470 	udelay(2);
1471 	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
1472 			UART_FCR_CLEAR_RCVR);
1473 	/*
1474 	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
1475 	 * TX_FIFO_E bit is 1.
1476 	 */
1477 	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
1478 				(UART_LSR_THRE | UART_LSR_DR))) {
1479 		timeout--;
1480 		if (!timeout) {
1481 			/* Should *never* happen. we warn and carry on */
1482 			dev_crit(up->dev, "Errata i202: timedout %x\n",
1483 						serial_in(up, UART_LSR));
1484 			break;
1485 		}
1486 		udelay(1);
1487 	}
1488 }
1489 
1490 #ifdef CONFIG_PM_RUNTIME
1491 static void serial_omap_restore_context(struct uart_omap_port *up)
1492 {
1493 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1494 		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
1495 	else
1496 		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
1497 
1498 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1499 	serial_out(up, UART_EFR, UART_EFR_ECB);
1500 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1501 	serial_out(up, UART_IER, 0x0);
1502 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1503 	serial_out(up, UART_DLL, up->dll);
1504 	serial_out(up, UART_DLM, up->dlh);
1505 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1506 	serial_out(up, UART_IER, up->ier);
1507 	serial_out(up, UART_FCR, up->fcr);
1508 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1509 	serial_out(up, UART_MCR, up->mcr);
1510 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1511 	serial_out(up, UART_OMAP_SCR, up->scr);
1512 	serial_out(up, UART_EFR, up->efr);
1513 	serial_out(up, UART_LCR, up->lcr);
1514 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1515 		serial_omap_mdr1_errataset(up, up->mdr1);
1516 	else
1517 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1518 }
1519 
1520 static int serial_omap_runtime_suspend(struct device *dev)
1521 {
1522 	struct uart_omap_port *up = dev_get_drvdata(dev);
1523 	struct omap_uart_port_info *pdata = dev->platform_data;
1524 
1525 	if (!up)
1526 		return -EINVAL;
1527 
1528 	if (!pdata)
1529 		return 0;
1530 
1531 	up->context_loss_cnt = serial_omap_get_context_loss_count(up);
1532 
1533 	if (device_may_wakeup(dev)) {
1534 		if (!up->wakeups_enabled) {
1535 			serial_omap_enable_wakeup(up, true);
1536 			up->wakeups_enabled = true;
1537 		}
1538 	} else {
1539 		if (up->wakeups_enabled) {
1540 			serial_omap_enable_wakeup(up, false);
1541 			up->wakeups_enabled = false;
1542 		}
1543 	}
1544 
1545 	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1546 	schedule_work(&up->qos_work);
1547 
1548 	return 0;
1549 }
1550 
1551 static int serial_omap_runtime_resume(struct device *dev)
1552 {
1553 	struct uart_omap_port *up = dev_get_drvdata(dev);
1554 
1555 	int loss_cnt = serial_omap_get_context_loss_count(up);
1556 
1557 	if (loss_cnt < 0) {
1558 		dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n",
1559 			loss_cnt);
1560 		serial_omap_restore_context(up);
1561 	} else if (up->context_loss_cnt != loss_cnt) {
1562 		serial_omap_restore_context(up);
1563 	}
1564 	up->latency = up->calc_latency;
1565 	schedule_work(&up->qos_work);
1566 
1567 	return 0;
1568 }
1569 #endif
1570 
1571 static const struct dev_pm_ops serial_omap_dev_pm_ops = {
1572 	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
1573 	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
1574 				serial_omap_runtime_resume, NULL)
1575 };
1576 
1577 #if defined(CONFIG_OF)
1578 static const struct of_device_id omap_serial_of_match[] = {
1579 	{ .compatible = "ti,omap2-uart" },
1580 	{ .compatible = "ti,omap3-uart" },
1581 	{ .compatible = "ti,omap4-uart" },
1582 	{},
1583 };
1584 MODULE_DEVICE_TABLE(of, omap_serial_of_match);
1585 #endif
1586 
1587 static struct platform_driver serial_omap_driver = {
1588 	.probe          = serial_omap_probe,
1589 	.remove         = serial_omap_remove,
1590 	.driver		= {
1591 		.name	= DRIVER_NAME,
1592 		.pm	= &serial_omap_dev_pm_ops,
1593 		.of_match_table = of_match_ptr(omap_serial_of_match),
1594 	},
1595 };
1596 
1597 static int __init serial_omap_init(void)
1598 {
1599 	int ret;
1600 
1601 	ret = uart_register_driver(&serial_omap_reg);
1602 	if (ret != 0)
1603 		return ret;
1604 	ret = platform_driver_register(&serial_omap_driver);
1605 	if (ret != 0)
1606 		uart_unregister_driver(&serial_omap_reg);
1607 	return ret;
1608 }
1609 
1610 static void __exit serial_omap_exit(void)
1611 {
1612 	platform_driver_unregister(&serial_omap_driver);
1613 	uart_unregister_driver(&serial_omap_reg);
1614 }
1615 
1616 module_init(serial_omap_init);
1617 module_exit(serial_omap_exit);
1618 
1619 MODULE_DESCRIPTION("OMAP High Speed UART driver");
1620 MODULE_LICENSE("GPL");
1621 MODULE_AUTHOR("Texas Instruments Inc");
1622