xref: /linux/drivers/tty/serial/omap-serial.c (revision e899966f626f1f657a4a7bac736c0b9ae5a243ea)
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/of_irq.h>
43 #include <linux/gpio.h>
44 #include <linux/of_gpio.h>
45 #include <linux/platform_data/serial-omap.h>
46 
47 #include <dt-bindings/gpio/gpio.h>
48 
49 #define OMAP_MAX_HSUART_PORTS	6
50 
51 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
52 
53 #define OMAP_UART_REV_42 0x0402
54 #define OMAP_UART_REV_46 0x0406
55 #define OMAP_UART_REV_52 0x0502
56 #define OMAP_UART_REV_63 0x0603
57 
58 #define OMAP_UART_TX_WAKEUP_EN		BIT(7)
59 
60 /* Feature flags */
61 #define OMAP_UART_WER_HAS_TX_WAKEUP	BIT(0)
62 
63 #define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
64 #define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
65 
66 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz*/
67 
68 /* SCR register bitmasks */
69 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
70 #define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK		(1 << 6)
71 #define OMAP_UART_SCR_TX_EMPTY			(1 << 3)
72 
73 /* FCR register bitmasks */
74 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)
75 #define OMAP_UART_FCR_TX_FIFO_TRIG_MASK			(0x3 << 4)
76 
77 /* MVR register bitmasks */
78 #define OMAP_UART_MVR_SCHEME_SHIFT	30
79 
80 #define OMAP_UART_LEGACY_MVR_MAJ_MASK	0xf0
81 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT	4
82 #define OMAP_UART_LEGACY_MVR_MIN_MASK	0x0f
83 
84 #define OMAP_UART_MVR_MAJ_MASK		0x700
85 #define OMAP_UART_MVR_MAJ_SHIFT		8
86 #define OMAP_UART_MVR_MIN_MASK		0x3f
87 
88 #define OMAP_UART_DMA_CH_FREE	-1
89 
90 #define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
91 #define OMAP_MODE13X_SPEED	230400
92 
93 /* WER = 0x7F
94  * Enable module level wakeup in WER reg
95  */
96 #define OMAP_UART_WER_MOD_WKUP	0X7F
97 
98 /* Enable XON/XOFF flow control on output */
99 #define OMAP_UART_SW_TX		0x08
100 
101 /* Enable XON/XOFF flow control on input */
102 #define OMAP_UART_SW_RX		0x02
103 
104 #define OMAP_UART_SW_CLR	0xF0
105 
106 #define OMAP_UART_TCR_TRIG	0x0F
107 
108 struct uart_omap_dma {
109 	u8			uart_dma_tx;
110 	u8			uart_dma_rx;
111 	int			rx_dma_channel;
112 	int			tx_dma_channel;
113 	dma_addr_t		rx_buf_dma_phys;
114 	dma_addr_t		tx_buf_dma_phys;
115 	unsigned int		uart_base;
116 	/*
117 	 * Buffer for rx dma.It is not required for tx because the buffer
118 	 * comes from port structure.
119 	 */
120 	unsigned char		*rx_buf;
121 	unsigned int		prev_rx_dma_pos;
122 	int			tx_buf_size;
123 	int			tx_dma_used;
124 	int			rx_dma_used;
125 	spinlock_t		tx_lock;
126 	spinlock_t		rx_lock;
127 	/* timer to poll activity on rx dma */
128 	struct timer_list	rx_timer;
129 	unsigned int		rx_buf_size;
130 	unsigned int		rx_poll_rate;
131 	unsigned int		rx_timeout;
132 };
133 
134 struct uart_omap_port {
135 	struct uart_port	port;
136 	struct uart_omap_dma	uart_dma;
137 	struct device		*dev;
138 	int			wakeirq;
139 
140 	unsigned char		ier;
141 	unsigned char		lcr;
142 	unsigned char		mcr;
143 	unsigned char		fcr;
144 	unsigned char		efr;
145 	unsigned char		dll;
146 	unsigned char		dlh;
147 	unsigned char		mdr1;
148 	unsigned char		scr;
149 	unsigned char		wer;
150 
151 	int			use_dma;
152 	/*
153 	 * Some bits in registers are cleared on a read, so they must
154 	 * be saved whenever the register is read but the bits will not
155 	 * be immediately processed.
156 	 */
157 	unsigned int		lsr_break_flag;
158 	unsigned char		msr_saved_flags;
159 	char			name[20];
160 	unsigned long		port_activity;
161 	int			context_loss_cnt;
162 	u32			errata;
163 	u8			wakeups_enabled;
164 	u32			features;
165 
166 	int			DTR_gpio;
167 	int			DTR_inverted;
168 	int			DTR_active;
169 
170 	struct serial_rs485	rs485;
171 	int			rts_gpio;
172 
173 	struct pm_qos_request	pm_qos_request;
174 	u32			latency;
175 	u32			calc_latency;
176 	struct work_struct	qos_work;
177 	bool			is_suspending;
178 };
179 
180 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
181 
182 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
183 
184 /* Forward declaration of functions */
185 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
186 
187 static struct workqueue_struct *serial_omap_uart_wq;
188 
189 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
190 {
191 	offset <<= up->port.regshift;
192 	return readw(up->port.membase + offset);
193 }
194 
195 static inline void serial_out(struct uart_omap_port *up, int offset, int value)
196 {
197 	offset <<= up->port.regshift;
198 	writew(value, up->port.membase + offset);
199 }
200 
201 static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
202 {
203 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
204 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
205 		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
206 	serial_out(up, UART_FCR, 0);
207 }
208 
209 static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
210 {
211 	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
212 
213 	if (!pdata || !pdata->get_context_loss_count)
214 		return -EINVAL;
215 
216 	return pdata->get_context_loss_count(up->dev);
217 }
218 
219 static inline void serial_omap_enable_wakeirq(struct uart_omap_port *up,
220 				       bool enable)
221 {
222 	if (!up->wakeirq)
223 		return;
224 
225 	if (enable)
226 		enable_irq(up->wakeirq);
227 	else
228 		disable_irq_nosync(up->wakeirq);
229 }
230 
231 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
232 {
233 	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
234 
235 	if (enable == up->wakeups_enabled)
236 		return;
237 
238 	serial_omap_enable_wakeirq(up, enable);
239 	up->wakeups_enabled = enable;
240 
241 	if (!pdata || !pdata->enable_wakeup)
242 		return;
243 
244 	pdata->enable_wakeup(up->dev, enable);
245 }
246 
247 /*
248  * serial_omap_baud_is_mode16 - check if baud rate is MODE16X
249  * @port: uart port info
250  * @baud: baudrate for which mode needs to be determined
251  *
252  * Returns true if baud rate is MODE16X and false if MODE13X
253  * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values,
254  * and Error Rates" determines modes not for all common baud rates.
255  * E.g. for 1000000 baud rate mode must be 16x, but according to that
256  * table it's determined as 13x.
257  */
258 static bool
259 serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
260 {
261 	unsigned int n13 = port->uartclk / (13 * baud);
262 	unsigned int n16 = port->uartclk / (16 * baud);
263 	int baudAbsDiff13 = baud - (port->uartclk / (13 * n13));
264 	int baudAbsDiff16 = baud - (port->uartclk / (16 * n16));
265 	if (baudAbsDiff13 < 0)
266 		baudAbsDiff13 = -baudAbsDiff13;
267 	if (baudAbsDiff16 < 0)
268 		baudAbsDiff16 = -baudAbsDiff16;
269 
270 	return (baudAbsDiff13 >= baudAbsDiff16);
271 }
272 
273 /*
274  * serial_omap_get_divisor - calculate divisor value
275  * @port: uart port info
276  * @baud: baudrate for which divisor needs to be calculated.
277  */
278 static unsigned int
279 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
280 {
281 	unsigned int mode;
282 
283 	if (!serial_omap_baud_is_mode16(port, baud))
284 		mode = 13;
285 	else
286 		mode = 16;
287 	return port->uartclk/(mode * baud);
288 }
289 
290 static void serial_omap_enable_ms(struct uart_port *port)
291 {
292 	struct uart_omap_port *up = to_uart_omap_port(port);
293 
294 	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);
295 
296 	pm_runtime_get_sync(up->dev);
297 	up->ier |= UART_IER_MSI;
298 	serial_out(up, UART_IER, up->ier);
299 	pm_runtime_mark_last_busy(up->dev);
300 	pm_runtime_put_autosuspend(up->dev);
301 }
302 
303 static void serial_omap_stop_tx(struct uart_port *port)
304 {
305 	struct uart_omap_port *up = to_uart_omap_port(port);
306 	int res;
307 
308 	pm_runtime_get_sync(up->dev);
309 
310 	/* Handle RS-485 */
311 	if (up->rs485.flags & SER_RS485_ENABLED) {
312 		if (up->scr & OMAP_UART_SCR_TX_EMPTY) {
313 			/* THR interrupt is fired when both TX FIFO and TX
314 			 * shift register are empty. This means there's nothing
315 			 * left to transmit now, so make sure the THR interrupt
316 			 * is fired when TX FIFO is below the trigger level,
317 			 * disable THR interrupts and toggle the RS-485 GPIO
318 			 * data direction pin if needed.
319 			 */
320 			up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
321 			serial_out(up, UART_OMAP_SCR, up->scr);
322 			res = (up->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 1 : 0;
323 			if (gpio_get_value(up->rts_gpio) != res) {
324 				if (up->rs485.delay_rts_after_send > 0)
325 					mdelay(up->rs485.delay_rts_after_send);
326 				gpio_set_value(up->rts_gpio, res);
327 			}
328 		} else {
329 			/* We're asked to stop, but there's still stuff in the
330 			 * UART FIFO, so make sure the THR interrupt is fired
331 			 * when both TX FIFO and TX shift register are empty.
332 			 * The next THR interrupt (if no transmission is started
333 			 * in the meantime) will indicate the end of a
334 			 * transmission. Therefore we _don't_ disable THR
335 			 * interrupts in this situation.
336 			 */
337 			up->scr |= OMAP_UART_SCR_TX_EMPTY;
338 			serial_out(up, UART_OMAP_SCR, up->scr);
339 			return;
340 		}
341 	}
342 
343 	if (up->ier & UART_IER_THRI) {
344 		up->ier &= ~UART_IER_THRI;
345 		serial_out(up, UART_IER, up->ier);
346 	}
347 
348 	if ((up->rs485.flags & SER_RS485_ENABLED) &&
349 	    !(up->rs485.flags & SER_RS485_RX_DURING_TX)) {
350 		/*
351 		 * Empty the RX FIFO, we are not interested in anything
352 		 * received during the half-duplex transmission.
353 		 */
354 		serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_RCVR);
355 		/* Re-enable RX interrupts */
356 		up->ier |= UART_IER_RLSI | UART_IER_RDI;
357 		up->port.read_status_mask |= UART_LSR_DR;
358 		serial_out(up, UART_IER, up->ier);
359 	}
360 
361 	pm_runtime_mark_last_busy(up->dev);
362 	pm_runtime_put_autosuspend(up->dev);
363 }
364 
365 static void serial_omap_stop_rx(struct uart_port *port)
366 {
367 	struct uart_omap_port *up = to_uart_omap_port(port);
368 
369 	pm_runtime_get_sync(up->dev);
370 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
371 	up->port.read_status_mask &= ~UART_LSR_DR;
372 	serial_out(up, UART_IER, up->ier);
373 	pm_runtime_mark_last_busy(up->dev);
374 	pm_runtime_put_autosuspend(up->dev);
375 }
376 
377 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
378 {
379 	struct circ_buf *xmit = &up->port.state->xmit;
380 	int count;
381 
382 	if (up->port.x_char) {
383 		serial_out(up, UART_TX, up->port.x_char);
384 		up->port.icount.tx++;
385 		up->port.x_char = 0;
386 		return;
387 	}
388 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
389 		serial_omap_stop_tx(&up->port);
390 		return;
391 	}
392 	count = up->port.fifosize / 4;
393 	do {
394 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
395 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
396 		up->port.icount.tx++;
397 		if (uart_circ_empty(xmit))
398 			break;
399 	} while (--count > 0);
400 
401 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
402 		spin_unlock(&up->port.lock);
403 		uart_write_wakeup(&up->port);
404 		spin_lock(&up->port.lock);
405 	}
406 
407 	if (uart_circ_empty(xmit))
408 		serial_omap_stop_tx(&up->port);
409 }
410 
411 static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
412 {
413 	if (!(up->ier & UART_IER_THRI)) {
414 		up->ier |= UART_IER_THRI;
415 		serial_out(up, UART_IER, up->ier);
416 	}
417 }
418 
419 static void serial_omap_start_tx(struct uart_port *port)
420 {
421 	struct uart_omap_port *up = to_uart_omap_port(port);
422 	int res;
423 
424 	pm_runtime_get_sync(up->dev);
425 
426 	/* Handle RS-485 */
427 	if (up->rs485.flags & SER_RS485_ENABLED) {
428 		/* Fire THR interrupts when FIFO is below trigger level */
429 		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
430 		serial_out(up, UART_OMAP_SCR, up->scr);
431 
432 		/* if rts not already enabled */
433 		res = (up->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
434 		if (gpio_get_value(up->rts_gpio) != res) {
435 			gpio_set_value(up->rts_gpio, res);
436 			if (up->rs485.delay_rts_before_send > 0)
437 				mdelay(up->rs485.delay_rts_before_send);
438 		}
439 	}
440 
441 	if ((up->rs485.flags & SER_RS485_ENABLED) &&
442 	    !(up->rs485.flags & SER_RS485_RX_DURING_TX))
443 		serial_omap_stop_rx(port);
444 
445 	serial_omap_enable_ier_thri(up);
446 	pm_runtime_mark_last_busy(up->dev);
447 	pm_runtime_put_autosuspend(up->dev);
448 }
449 
450 static void serial_omap_throttle(struct uart_port *port)
451 {
452 	struct uart_omap_port *up = to_uart_omap_port(port);
453 	unsigned long flags;
454 
455 	pm_runtime_get_sync(up->dev);
456 	spin_lock_irqsave(&up->port.lock, flags);
457 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
458 	serial_out(up, UART_IER, up->ier);
459 	spin_unlock_irqrestore(&up->port.lock, flags);
460 	pm_runtime_mark_last_busy(up->dev);
461 	pm_runtime_put_autosuspend(up->dev);
462 }
463 
464 static void serial_omap_unthrottle(struct uart_port *port)
465 {
466 	struct uart_omap_port *up = to_uart_omap_port(port);
467 	unsigned long flags;
468 
469 	pm_runtime_get_sync(up->dev);
470 	spin_lock_irqsave(&up->port.lock, flags);
471 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
472 	serial_out(up, UART_IER, up->ier);
473 	spin_unlock_irqrestore(&up->port.lock, flags);
474 	pm_runtime_mark_last_busy(up->dev);
475 	pm_runtime_put_autosuspend(up->dev);
476 }
477 
478 static unsigned int check_modem_status(struct uart_omap_port *up)
479 {
480 	unsigned int status;
481 
482 	status = serial_in(up, UART_MSR);
483 	status |= up->msr_saved_flags;
484 	up->msr_saved_flags = 0;
485 	if ((status & UART_MSR_ANY_DELTA) == 0)
486 		return status;
487 
488 	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
489 	    up->port.state != NULL) {
490 		if (status & UART_MSR_TERI)
491 			up->port.icount.rng++;
492 		if (status & UART_MSR_DDSR)
493 			up->port.icount.dsr++;
494 		if (status & UART_MSR_DDCD)
495 			uart_handle_dcd_change
496 				(&up->port, status & UART_MSR_DCD);
497 		if (status & UART_MSR_DCTS)
498 			uart_handle_cts_change
499 				(&up->port, status & UART_MSR_CTS);
500 		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
501 	}
502 
503 	return status;
504 }
505 
506 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
507 {
508 	unsigned int flag;
509 	unsigned char ch = 0;
510 
511 	if (likely(lsr & UART_LSR_DR))
512 		ch = serial_in(up, UART_RX);
513 
514 	up->port.icount.rx++;
515 	flag = TTY_NORMAL;
516 
517 	if (lsr & UART_LSR_BI) {
518 		flag = TTY_BREAK;
519 		lsr &= ~(UART_LSR_FE | UART_LSR_PE);
520 		up->port.icount.brk++;
521 		/*
522 		 * We do the SysRQ and SAK checking
523 		 * here because otherwise the break
524 		 * may get masked by ignore_status_mask
525 		 * or read_status_mask.
526 		 */
527 		if (uart_handle_break(&up->port))
528 			return;
529 
530 	}
531 
532 	if (lsr & UART_LSR_PE) {
533 		flag = TTY_PARITY;
534 		up->port.icount.parity++;
535 	}
536 
537 	if (lsr & UART_LSR_FE) {
538 		flag = TTY_FRAME;
539 		up->port.icount.frame++;
540 	}
541 
542 	if (lsr & UART_LSR_OE)
543 		up->port.icount.overrun++;
544 
545 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
546 	if (up->port.line == up->port.cons->index) {
547 		/* Recover the break flag from console xmit */
548 		lsr |= up->lsr_break_flag;
549 	}
550 #endif
551 	uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag);
552 }
553 
554 static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
555 {
556 	unsigned char ch = 0;
557 	unsigned int flag;
558 
559 	if (!(lsr & UART_LSR_DR))
560 		return;
561 
562 	ch = serial_in(up, UART_RX);
563 	flag = TTY_NORMAL;
564 	up->port.icount.rx++;
565 
566 	if (uart_handle_sysrq_char(&up->port, ch))
567 		return;
568 
569 	uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
570 }
571 
572 /**
573  * serial_omap_irq() - This handles the interrupt from one port
574  * @irq: uart port irq number
575  * @dev_id: uart port info
576  */
577 static irqreturn_t serial_omap_irq(int irq, void *dev_id)
578 {
579 	struct uart_omap_port *up = dev_id;
580 	unsigned int iir, lsr;
581 	unsigned int type;
582 	irqreturn_t ret = IRQ_NONE;
583 	int max_count = 256;
584 
585 	spin_lock(&up->port.lock);
586 	pm_runtime_get_sync(up->dev);
587 
588 	do {
589 		iir = serial_in(up, UART_IIR);
590 		if (iir & UART_IIR_NO_INT)
591 			break;
592 
593 		ret = IRQ_HANDLED;
594 		lsr = serial_in(up, UART_LSR);
595 
596 		/* extract IRQ type from IIR register */
597 		type = iir & 0x3e;
598 
599 		switch (type) {
600 		case UART_IIR_MSI:
601 			check_modem_status(up);
602 			break;
603 		case UART_IIR_THRI:
604 			transmit_chars(up, lsr);
605 			break;
606 		case UART_IIR_RX_TIMEOUT:
607 			/* FALLTHROUGH */
608 		case UART_IIR_RDI:
609 			serial_omap_rdi(up, lsr);
610 			break;
611 		case UART_IIR_RLSI:
612 			serial_omap_rlsi(up, lsr);
613 			break;
614 		case UART_IIR_CTS_RTS_DSR:
615 			/* simply try again */
616 			break;
617 		case UART_IIR_XOFF:
618 			/* FALLTHROUGH */
619 		default:
620 			break;
621 		}
622 	} while (!(iir & UART_IIR_NO_INT) && max_count--);
623 
624 	spin_unlock(&up->port.lock);
625 
626 	tty_flip_buffer_push(&up->port.state->port);
627 
628 	pm_runtime_mark_last_busy(up->dev);
629 	pm_runtime_put_autosuspend(up->dev);
630 	up->port_activity = jiffies;
631 
632 	return ret;
633 }
634 
635 static unsigned int serial_omap_tx_empty(struct uart_port *port)
636 {
637 	struct uart_omap_port *up = to_uart_omap_port(port);
638 	unsigned long flags = 0;
639 	unsigned int ret = 0;
640 
641 	pm_runtime_get_sync(up->dev);
642 	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
643 	spin_lock_irqsave(&up->port.lock, flags);
644 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
645 	spin_unlock_irqrestore(&up->port.lock, flags);
646 	pm_runtime_mark_last_busy(up->dev);
647 	pm_runtime_put_autosuspend(up->dev);
648 	return ret;
649 }
650 
651 static unsigned int serial_omap_get_mctrl(struct uart_port *port)
652 {
653 	struct uart_omap_port *up = to_uart_omap_port(port);
654 	unsigned int status;
655 	unsigned int ret = 0;
656 
657 	pm_runtime_get_sync(up->dev);
658 	status = check_modem_status(up);
659 	pm_runtime_mark_last_busy(up->dev);
660 	pm_runtime_put_autosuspend(up->dev);
661 
662 	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);
663 
664 	if (status & UART_MSR_DCD)
665 		ret |= TIOCM_CAR;
666 	if (status & UART_MSR_RI)
667 		ret |= TIOCM_RNG;
668 	if (status & UART_MSR_DSR)
669 		ret |= TIOCM_DSR;
670 	if (status & UART_MSR_CTS)
671 		ret |= TIOCM_CTS;
672 	return ret;
673 }
674 
675 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
676 {
677 	struct uart_omap_port *up = to_uart_omap_port(port);
678 	unsigned char mcr = 0, old_mcr;
679 
680 	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
681 	if (mctrl & TIOCM_RTS)
682 		mcr |= UART_MCR_RTS;
683 	if (mctrl & TIOCM_DTR)
684 		mcr |= UART_MCR_DTR;
685 	if (mctrl & TIOCM_OUT1)
686 		mcr |= UART_MCR_OUT1;
687 	if (mctrl & TIOCM_OUT2)
688 		mcr |= UART_MCR_OUT2;
689 	if (mctrl & TIOCM_LOOP)
690 		mcr |= UART_MCR_LOOP;
691 
692 	pm_runtime_get_sync(up->dev);
693 	old_mcr = serial_in(up, UART_MCR);
694 	old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 |
695 		     UART_MCR_DTR | UART_MCR_RTS);
696 	up->mcr = old_mcr | mcr;
697 	serial_out(up, UART_MCR, up->mcr);
698 	pm_runtime_mark_last_busy(up->dev);
699 	pm_runtime_put_autosuspend(up->dev);
700 
701 	if (gpio_is_valid(up->DTR_gpio) &&
702 	    !!(mctrl & TIOCM_DTR) != up->DTR_active) {
703 		up->DTR_active = !up->DTR_active;
704 		if (gpio_cansleep(up->DTR_gpio))
705 			schedule_work(&up->qos_work);
706 		else
707 			gpio_set_value(up->DTR_gpio,
708 				       up->DTR_active != up->DTR_inverted);
709 	}
710 }
711 
712 static void serial_omap_break_ctl(struct uart_port *port, int break_state)
713 {
714 	struct uart_omap_port *up = to_uart_omap_port(port);
715 	unsigned long flags = 0;
716 
717 	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
718 	pm_runtime_get_sync(up->dev);
719 	spin_lock_irqsave(&up->port.lock, flags);
720 	if (break_state == -1)
721 		up->lcr |= UART_LCR_SBC;
722 	else
723 		up->lcr &= ~UART_LCR_SBC;
724 	serial_out(up, UART_LCR, up->lcr);
725 	spin_unlock_irqrestore(&up->port.lock, flags);
726 	pm_runtime_mark_last_busy(up->dev);
727 	pm_runtime_put_autosuspend(up->dev);
728 }
729 
730 static int serial_omap_startup(struct uart_port *port)
731 {
732 	struct uart_omap_port *up = to_uart_omap_port(port);
733 	unsigned long flags = 0;
734 	int retval;
735 
736 	/*
737 	 * Allocate the IRQ
738 	 */
739 	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
740 				up->name, up);
741 	if (retval)
742 		return retval;
743 
744 	/* Optional wake-up IRQ */
745 	if (up->wakeirq) {
746 		retval = request_irq(up->wakeirq, serial_omap_irq,
747 				     up->port.irqflags, up->name, up);
748 		if (retval) {
749 			free_irq(up->port.irq, up);
750 			return retval;
751 		}
752 		disable_irq(up->wakeirq);
753 	}
754 
755 	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
756 
757 	pm_runtime_get_sync(up->dev);
758 	/*
759 	 * Clear the FIFO buffers and disable them.
760 	 * (they will be reenabled in set_termios())
761 	 */
762 	serial_omap_clear_fifos(up);
763 	/* For Hardware flow control */
764 	serial_out(up, UART_MCR, UART_MCR_RTS);
765 
766 	/*
767 	 * Clear the interrupt registers.
768 	 */
769 	(void) serial_in(up, UART_LSR);
770 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
771 		(void) serial_in(up, UART_RX);
772 	(void) serial_in(up, UART_IIR);
773 	(void) serial_in(up, UART_MSR);
774 
775 	/*
776 	 * Now, initialize the UART
777 	 */
778 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
779 	spin_lock_irqsave(&up->port.lock, flags);
780 	/*
781 	 * Most PC uarts need OUT2 raised to enable interrupts.
782 	 */
783 	up->port.mctrl |= TIOCM_OUT2;
784 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
785 	spin_unlock_irqrestore(&up->port.lock, flags);
786 
787 	up->msr_saved_flags = 0;
788 	/*
789 	 * Finally, enable interrupts. Note: Modem status interrupts
790 	 * are set via set_termios(), which will be occurring imminently
791 	 * anyway, so we don't enable them here.
792 	 */
793 	up->ier = UART_IER_RLSI | UART_IER_RDI;
794 	serial_out(up, UART_IER, up->ier);
795 
796 	/* Enable module level wake up */
797 	up->wer = OMAP_UART_WER_MOD_WKUP;
798 	if (up->features & OMAP_UART_WER_HAS_TX_WAKEUP)
799 		up->wer |= OMAP_UART_TX_WAKEUP_EN;
800 
801 	serial_out(up, UART_OMAP_WER, up->wer);
802 
803 	pm_runtime_mark_last_busy(up->dev);
804 	pm_runtime_put_autosuspend(up->dev);
805 	up->port_activity = jiffies;
806 	return 0;
807 }
808 
809 static void serial_omap_shutdown(struct uart_port *port)
810 {
811 	struct uart_omap_port *up = to_uart_omap_port(port);
812 	unsigned long flags = 0;
813 
814 	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);
815 
816 	pm_runtime_get_sync(up->dev);
817 	/*
818 	 * Disable interrupts from this port
819 	 */
820 	up->ier = 0;
821 	serial_out(up, UART_IER, 0);
822 
823 	spin_lock_irqsave(&up->port.lock, flags);
824 	up->port.mctrl &= ~TIOCM_OUT2;
825 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
826 	spin_unlock_irqrestore(&up->port.lock, flags);
827 
828 	/*
829 	 * Disable break condition and FIFOs
830 	 */
831 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
832 	serial_omap_clear_fifos(up);
833 
834 	/*
835 	 * Read data port to reset things, and then free the irq
836 	 */
837 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
838 		(void) serial_in(up, UART_RX);
839 
840 	pm_runtime_mark_last_busy(up->dev);
841 	pm_runtime_put_autosuspend(up->dev);
842 	free_irq(up->port.irq, up);
843 	if (up->wakeirq)
844 		free_irq(up->wakeirq, up);
845 }
846 
847 static void serial_omap_uart_qos_work(struct work_struct *work)
848 {
849 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
850 						qos_work);
851 
852 	pm_qos_update_request(&up->pm_qos_request, up->latency);
853 	if (gpio_is_valid(up->DTR_gpio))
854 		gpio_set_value_cansleep(up->DTR_gpio,
855 					up->DTR_active != up->DTR_inverted);
856 }
857 
858 static void
859 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
860 			struct ktermios *old)
861 {
862 	struct uart_omap_port *up = to_uart_omap_port(port);
863 	unsigned char cval = 0;
864 	unsigned long flags = 0;
865 	unsigned int baud, quot;
866 
867 	switch (termios->c_cflag & CSIZE) {
868 	case CS5:
869 		cval = UART_LCR_WLEN5;
870 		break;
871 	case CS6:
872 		cval = UART_LCR_WLEN6;
873 		break;
874 	case CS7:
875 		cval = UART_LCR_WLEN7;
876 		break;
877 	default:
878 	case CS8:
879 		cval = UART_LCR_WLEN8;
880 		break;
881 	}
882 
883 	if (termios->c_cflag & CSTOPB)
884 		cval |= UART_LCR_STOP;
885 	if (termios->c_cflag & PARENB)
886 		cval |= UART_LCR_PARITY;
887 	if (!(termios->c_cflag & PARODD))
888 		cval |= UART_LCR_EPAR;
889 	if (termios->c_cflag & CMSPAR)
890 		cval |= UART_LCR_SPAR;
891 
892 	/*
893 	 * Ask the core to calculate the divisor for us.
894 	 */
895 
896 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
897 	quot = serial_omap_get_divisor(port, baud);
898 
899 	/* calculate wakeup latency constraint */
900 	up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
901 	up->latency = up->calc_latency;
902 	schedule_work(&up->qos_work);
903 
904 	up->dll = quot & 0xff;
905 	up->dlh = quot >> 8;
906 	up->mdr1 = UART_OMAP_MDR1_DISABLE;
907 
908 	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
909 			UART_FCR_ENABLE_FIFO;
910 
911 	/*
912 	 * Ok, we're now changing the port state. Do it with
913 	 * interrupts disabled.
914 	 */
915 	pm_runtime_get_sync(up->dev);
916 	spin_lock_irqsave(&up->port.lock, flags);
917 
918 	/*
919 	 * Update the per-port timeout.
920 	 */
921 	uart_update_timeout(port, termios->c_cflag, baud);
922 
923 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
924 	if (termios->c_iflag & INPCK)
925 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
926 	if (termios->c_iflag & (BRKINT | PARMRK))
927 		up->port.read_status_mask |= UART_LSR_BI;
928 
929 	/*
930 	 * Characters to ignore
931 	 */
932 	up->port.ignore_status_mask = 0;
933 	if (termios->c_iflag & IGNPAR)
934 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
935 	if (termios->c_iflag & IGNBRK) {
936 		up->port.ignore_status_mask |= UART_LSR_BI;
937 		/*
938 		 * If we're ignoring parity and break indicators,
939 		 * ignore overruns too (for real raw support).
940 		 */
941 		if (termios->c_iflag & IGNPAR)
942 			up->port.ignore_status_mask |= UART_LSR_OE;
943 	}
944 
945 	/*
946 	 * ignore all characters if CREAD is not set
947 	 */
948 	if ((termios->c_cflag & CREAD) == 0)
949 		up->port.ignore_status_mask |= UART_LSR_DR;
950 
951 	/*
952 	 * Modem status interrupts
953 	 */
954 	up->ier &= ~UART_IER_MSI;
955 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
956 		up->ier |= UART_IER_MSI;
957 	serial_out(up, UART_IER, up->ier);
958 	serial_out(up, UART_LCR, cval);		/* reset DLAB */
959 	up->lcr = cval;
960 	up->scr = 0;
961 
962 	/* FIFOs and DMA Settings */
963 
964 	/* FCR can be changed only when the
965 	 * baud clock is not running
966 	 * DLL_REG and DLH_REG set to 0.
967 	 */
968 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
969 	serial_out(up, UART_DLL, 0);
970 	serial_out(up, UART_DLM, 0);
971 	serial_out(up, UART_LCR, 0);
972 
973 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
974 
975 	up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB;
976 	up->efr &= ~UART_EFR_SCD;
977 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
978 
979 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
980 	up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR;
981 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
982 	/* FIFO ENABLE, DMA MODE */
983 
984 	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
985 	/*
986 	 * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK
987 	 * sets Enables the granularity of 1 for TRIGGER RX
988 	 * level. Along with setting RX FIFO trigger level
989 	 * to 1 (as noted below, 16 characters) and TLR[3:0]
990 	 * to zero this will result RX FIFO threshold level
991 	 * to 1 character, instead of 16 as noted in comment
992 	 * below.
993 	 */
994 
995 	/* Set receive FIFO threshold to 16 characters and
996 	 * transmit FIFO threshold to 32 spaces
997 	 */
998 	up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
999 	up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
1000 	up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 |
1001 		UART_FCR_ENABLE_FIFO;
1002 
1003 	serial_out(up, UART_FCR, up->fcr);
1004 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1005 
1006 	serial_out(up, UART_OMAP_SCR, up->scr);
1007 
1008 	/* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */
1009 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1010 	serial_out(up, UART_MCR, up->mcr);
1011 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1012 	serial_out(up, UART_EFR, up->efr);
1013 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1014 
1015 	/* Protocol, Baud Rate, and Interrupt Settings */
1016 
1017 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1018 		serial_omap_mdr1_errataset(up, up->mdr1);
1019 	else
1020 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1021 
1022 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1023 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1024 
1025 	serial_out(up, UART_LCR, 0);
1026 	serial_out(up, UART_IER, 0);
1027 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1028 
1029 	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
1030 	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */
1031 
1032 	serial_out(up, UART_LCR, 0);
1033 	serial_out(up, UART_IER, up->ier);
1034 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1035 
1036 	serial_out(up, UART_EFR, up->efr);
1037 	serial_out(up, UART_LCR, cval);
1038 
1039 	if (!serial_omap_baud_is_mode16(port, baud))
1040 		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
1041 	else
1042 		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
1043 
1044 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1045 		serial_omap_mdr1_errataset(up, up->mdr1);
1046 	else
1047 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1048 
1049 	/* Configure flow control */
1050 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1051 
1052 	/* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */
1053 	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
1054 	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
1055 
1056 	/* Enable access to TCR/TLR */
1057 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1058 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1059 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
1060 
1061 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
1062 
1063 	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
1064 		/* Enable AUTORTS and AUTOCTS */
1065 		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
1066 
1067 		/* Ensure MCR RTS is asserted */
1068 		up->mcr |= UART_MCR_RTS;
1069 	} else {
1070 		/* Disable AUTORTS and AUTOCTS */
1071 		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
1072 	}
1073 
1074 	if (up->port.flags & UPF_SOFT_FLOW) {
1075 		/* clear SW control mode bits */
1076 		up->efr &= OMAP_UART_SW_CLR;
1077 
1078 		/*
1079 		 * IXON Flag:
1080 		 * Enable XON/XOFF flow control on input.
1081 		 * Receiver compares XON1, XOFF1.
1082 		 */
1083 		if (termios->c_iflag & IXON)
1084 			up->efr |= OMAP_UART_SW_RX;
1085 
1086 		/*
1087 		 * IXOFF Flag:
1088 		 * Enable XON/XOFF flow control on output.
1089 		 * Transmit XON1, XOFF1
1090 		 */
1091 		if (termios->c_iflag & IXOFF)
1092 			up->efr |= OMAP_UART_SW_TX;
1093 
1094 		/*
1095 		 * IXANY Flag:
1096 		 * Enable any character to restart output.
1097 		 * Operation resumes after receiving any
1098 		 * character after recognition of the XOFF character
1099 		 */
1100 		if (termios->c_iflag & IXANY)
1101 			up->mcr |= UART_MCR_XONANY;
1102 		else
1103 			up->mcr &= ~UART_MCR_XONANY;
1104 	}
1105 	serial_out(up, UART_MCR, up->mcr);
1106 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1107 	serial_out(up, UART_EFR, up->efr);
1108 	serial_out(up, UART_LCR, up->lcr);
1109 
1110 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
1111 
1112 	spin_unlock_irqrestore(&up->port.lock, flags);
1113 	pm_runtime_mark_last_busy(up->dev);
1114 	pm_runtime_put_autosuspend(up->dev);
1115 	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
1116 }
1117 
1118 static void
1119 serial_omap_pm(struct uart_port *port, unsigned int state,
1120 	       unsigned int oldstate)
1121 {
1122 	struct uart_omap_port *up = to_uart_omap_port(port);
1123 	unsigned char efr;
1124 
1125 	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);
1126 
1127 	pm_runtime_get_sync(up->dev);
1128 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1129 	efr = serial_in(up, UART_EFR);
1130 	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
1131 	serial_out(up, UART_LCR, 0);
1132 
1133 	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
1134 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1135 	serial_out(up, UART_EFR, efr);
1136 	serial_out(up, UART_LCR, 0);
1137 
1138 	if (!device_may_wakeup(up->dev)) {
1139 		if (!state)
1140 			pm_runtime_forbid(up->dev);
1141 		else
1142 			pm_runtime_allow(up->dev);
1143 	}
1144 
1145 	pm_runtime_mark_last_busy(up->dev);
1146 	pm_runtime_put_autosuspend(up->dev);
1147 }
1148 
1149 static void serial_omap_release_port(struct uart_port *port)
1150 {
1151 	dev_dbg(port->dev, "serial_omap_release_port+\n");
1152 }
1153 
1154 static int serial_omap_request_port(struct uart_port *port)
1155 {
1156 	dev_dbg(port->dev, "serial_omap_request_port+\n");
1157 	return 0;
1158 }
1159 
1160 static void serial_omap_config_port(struct uart_port *port, int flags)
1161 {
1162 	struct uart_omap_port *up = to_uart_omap_port(port);
1163 
1164 	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
1165 							up->port.line);
1166 	up->port.type = PORT_OMAP;
1167 	up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW;
1168 }
1169 
1170 static int
1171 serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
1172 {
1173 	/* we don't want the core code to modify any port params */
1174 	dev_dbg(port->dev, "serial_omap_verify_port+\n");
1175 	return -EINVAL;
1176 }
1177 
1178 static const char *
1179 serial_omap_type(struct uart_port *port)
1180 {
1181 	struct uart_omap_port *up = to_uart_omap_port(port);
1182 
1183 	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
1184 	return up->name;
1185 }
1186 
1187 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1188 
1189 static inline void wait_for_xmitr(struct uart_omap_port *up)
1190 {
1191 	unsigned int status, tmout = 10000;
1192 
1193 	/* Wait up to 10ms for the character(s) to be sent. */
1194 	do {
1195 		status = serial_in(up, UART_LSR);
1196 
1197 		if (status & UART_LSR_BI)
1198 			up->lsr_break_flag = UART_LSR_BI;
1199 
1200 		if (--tmout == 0)
1201 			break;
1202 		udelay(1);
1203 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
1204 
1205 	/* Wait up to 1s for flow control if necessary */
1206 	if (up->port.flags & UPF_CONS_FLOW) {
1207 		tmout = 1000000;
1208 		for (tmout = 1000000; tmout; tmout--) {
1209 			unsigned int msr = serial_in(up, UART_MSR);
1210 
1211 			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1212 			if (msr & UART_MSR_CTS)
1213 				break;
1214 
1215 			udelay(1);
1216 		}
1217 	}
1218 }
1219 
1220 #ifdef CONFIG_CONSOLE_POLL
1221 
1222 static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
1223 {
1224 	struct uart_omap_port *up = to_uart_omap_port(port);
1225 
1226 	pm_runtime_get_sync(up->dev);
1227 	wait_for_xmitr(up);
1228 	serial_out(up, UART_TX, ch);
1229 	pm_runtime_mark_last_busy(up->dev);
1230 	pm_runtime_put_autosuspend(up->dev);
1231 }
1232 
1233 static int serial_omap_poll_get_char(struct uart_port *port)
1234 {
1235 	struct uart_omap_port *up = to_uart_omap_port(port);
1236 	unsigned int status;
1237 
1238 	pm_runtime_get_sync(up->dev);
1239 	status = serial_in(up, UART_LSR);
1240 	if (!(status & UART_LSR_DR)) {
1241 		status = NO_POLL_CHAR;
1242 		goto out;
1243 	}
1244 
1245 	status = serial_in(up, UART_RX);
1246 
1247 out:
1248 	pm_runtime_mark_last_busy(up->dev);
1249 	pm_runtime_put_autosuspend(up->dev);
1250 
1251 	return status;
1252 }
1253 
1254 #endif /* CONFIG_CONSOLE_POLL */
1255 
1256 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
1257 
1258 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
1259 
1260 static struct uart_driver serial_omap_reg;
1261 
1262 static void serial_omap_console_putchar(struct uart_port *port, int ch)
1263 {
1264 	struct uart_omap_port *up = to_uart_omap_port(port);
1265 
1266 	wait_for_xmitr(up);
1267 	serial_out(up, UART_TX, ch);
1268 }
1269 
1270 static void
1271 serial_omap_console_write(struct console *co, const char *s,
1272 		unsigned int count)
1273 {
1274 	struct uart_omap_port *up = serial_omap_console_ports[co->index];
1275 	unsigned long flags;
1276 	unsigned int ier;
1277 	int locked = 1;
1278 
1279 	pm_runtime_get_sync(up->dev);
1280 
1281 	local_irq_save(flags);
1282 	if (up->port.sysrq)
1283 		locked = 0;
1284 	else if (oops_in_progress)
1285 		locked = spin_trylock(&up->port.lock);
1286 	else
1287 		spin_lock(&up->port.lock);
1288 
1289 	/*
1290 	 * First save the IER then disable the interrupts
1291 	 */
1292 	ier = serial_in(up, UART_IER);
1293 	serial_out(up, UART_IER, 0);
1294 
1295 	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
1296 
1297 	/*
1298 	 * Finally, wait for transmitter to become empty
1299 	 * and restore the IER
1300 	 */
1301 	wait_for_xmitr(up);
1302 	serial_out(up, UART_IER, ier);
1303 	/*
1304 	 * The receive handling will happen properly because the
1305 	 * receive ready bit will still be set; it is not cleared
1306 	 * on read.  However, modem control will not, we must
1307 	 * call it if we have saved something in the saved flags
1308 	 * while processing with interrupts off.
1309 	 */
1310 	if (up->msr_saved_flags)
1311 		check_modem_status(up);
1312 
1313 	pm_runtime_mark_last_busy(up->dev);
1314 	pm_runtime_put_autosuspend(up->dev);
1315 	if (locked)
1316 		spin_unlock(&up->port.lock);
1317 	local_irq_restore(flags);
1318 }
1319 
1320 static int __init
1321 serial_omap_console_setup(struct console *co, char *options)
1322 {
1323 	struct uart_omap_port *up;
1324 	int baud = 115200;
1325 	int bits = 8;
1326 	int parity = 'n';
1327 	int flow = 'n';
1328 
1329 	if (serial_omap_console_ports[co->index] == NULL)
1330 		return -ENODEV;
1331 	up = serial_omap_console_ports[co->index];
1332 
1333 	if (options)
1334 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1335 
1336 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
1337 }
1338 
1339 static struct console serial_omap_console = {
1340 	.name		= OMAP_SERIAL_NAME,
1341 	.write		= serial_omap_console_write,
1342 	.device		= uart_console_device,
1343 	.setup		= serial_omap_console_setup,
1344 	.flags		= CON_PRINTBUFFER,
1345 	.index		= -1,
1346 	.data		= &serial_omap_reg,
1347 };
1348 
1349 static void serial_omap_add_console_port(struct uart_omap_port *up)
1350 {
1351 	serial_omap_console_ports[up->port.line] = up;
1352 }
1353 
1354 #define OMAP_CONSOLE	(&serial_omap_console)
1355 
1356 #else
1357 
1358 #define OMAP_CONSOLE	NULL
1359 
1360 static inline void serial_omap_add_console_port(struct uart_omap_port *up)
1361 {}
1362 
1363 #endif
1364 
1365 /* Enable or disable the rs485 support */
1366 static void
1367 serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
1368 {
1369 	struct uart_omap_port *up = to_uart_omap_port(port);
1370 	unsigned long flags;
1371 	unsigned int mode;
1372 	int val;
1373 
1374 	pm_runtime_get_sync(up->dev);
1375 	spin_lock_irqsave(&up->port.lock, flags);
1376 
1377 	/* Disable interrupts from this port */
1378 	mode = up->ier;
1379 	up->ier = 0;
1380 	serial_out(up, UART_IER, 0);
1381 
1382 	/* store new config */
1383 	up->rs485 = *rs485conf;
1384 
1385 	/*
1386 	 * Just as a precaution, only allow rs485
1387 	 * to be enabled if the gpio pin is valid
1388 	 */
1389 	if (gpio_is_valid(up->rts_gpio)) {
1390 		/* enable / disable rts */
1391 		val = (up->rs485.flags & SER_RS485_ENABLED) ?
1392 			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
1393 		val = (up->rs485.flags & val) ? 1 : 0;
1394 		gpio_set_value(up->rts_gpio, val);
1395 	} else
1396 		up->rs485.flags &= ~SER_RS485_ENABLED;
1397 
1398 	/* Enable interrupts */
1399 	up->ier = mode;
1400 	serial_out(up, UART_IER, up->ier);
1401 
1402 	/* If RS-485 is disabled, make sure the THR interrupt is fired when
1403 	 * TX FIFO is below the trigger level.
1404 	 */
1405 	if (!(up->rs485.flags & SER_RS485_ENABLED) &&
1406 	    (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
1407 		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
1408 		serial_out(up, UART_OMAP_SCR, up->scr);
1409 	}
1410 
1411 	spin_unlock_irqrestore(&up->port.lock, flags);
1412 	pm_runtime_mark_last_busy(up->dev);
1413 	pm_runtime_put_autosuspend(up->dev);
1414 }
1415 
1416 static int
1417 serial_omap_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
1418 {
1419 	struct serial_rs485 rs485conf;
1420 
1421 	switch (cmd) {
1422 	case TIOCSRS485:
1423 		if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
1424 					sizeof(rs485conf)))
1425 			return -EFAULT;
1426 
1427 		serial_omap_config_rs485(port, &rs485conf);
1428 		break;
1429 
1430 	case TIOCGRS485:
1431 		if (copy_to_user((struct serial_rs485 *) arg,
1432 					&(to_uart_omap_port(port)->rs485),
1433 					sizeof(rs485conf)))
1434 			return -EFAULT;
1435 		break;
1436 
1437 	default:
1438 		return -ENOIOCTLCMD;
1439 	}
1440 	return 0;
1441 }
1442 
1443 
1444 static struct uart_ops serial_omap_pops = {
1445 	.tx_empty	= serial_omap_tx_empty,
1446 	.set_mctrl	= serial_omap_set_mctrl,
1447 	.get_mctrl	= serial_omap_get_mctrl,
1448 	.stop_tx	= serial_omap_stop_tx,
1449 	.start_tx	= serial_omap_start_tx,
1450 	.throttle	= serial_omap_throttle,
1451 	.unthrottle	= serial_omap_unthrottle,
1452 	.stop_rx	= serial_omap_stop_rx,
1453 	.enable_ms	= serial_omap_enable_ms,
1454 	.break_ctl	= serial_omap_break_ctl,
1455 	.startup	= serial_omap_startup,
1456 	.shutdown	= serial_omap_shutdown,
1457 	.set_termios	= serial_omap_set_termios,
1458 	.pm		= serial_omap_pm,
1459 	.type		= serial_omap_type,
1460 	.release_port	= serial_omap_release_port,
1461 	.request_port	= serial_omap_request_port,
1462 	.config_port	= serial_omap_config_port,
1463 	.verify_port	= serial_omap_verify_port,
1464 	.ioctl		= serial_omap_ioctl,
1465 #ifdef CONFIG_CONSOLE_POLL
1466 	.poll_put_char  = serial_omap_poll_put_char,
1467 	.poll_get_char  = serial_omap_poll_get_char,
1468 #endif
1469 };
1470 
1471 static struct uart_driver serial_omap_reg = {
1472 	.owner		= THIS_MODULE,
1473 	.driver_name	= "OMAP-SERIAL",
1474 	.dev_name	= OMAP_SERIAL_NAME,
1475 	.nr		= OMAP_MAX_HSUART_PORTS,
1476 	.cons		= OMAP_CONSOLE,
1477 };
1478 
1479 #ifdef CONFIG_PM_SLEEP
1480 static int serial_omap_prepare(struct device *dev)
1481 {
1482 	struct uart_omap_port *up = dev_get_drvdata(dev);
1483 
1484 	up->is_suspending = true;
1485 
1486 	return 0;
1487 }
1488 
1489 static void serial_omap_complete(struct device *dev)
1490 {
1491 	struct uart_omap_port *up = dev_get_drvdata(dev);
1492 
1493 	up->is_suspending = false;
1494 }
1495 
1496 static int serial_omap_suspend(struct device *dev)
1497 {
1498 	struct uart_omap_port *up = dev_get_drvdata(dev);
1499 
1500 	uart_suspend_port(&serial_omap_reg, &up->port);
1501 	flush_work(&up->qos_work);
1502 
1503 	if (device_may_wakeup(dev))
1504 		serial_omap_enable_wakeup(up, true);
1505 	else
1506 		serial_omap_enable_wakeup(up, false);
1507 
1508 	return 0;
1509 }
1510 
1511 static int serial_omap_resume(struct device *dev)
1512 {
1513 	struct uart_omap_port *up = dev_get_drvdata(dev);
1514 
1515 	if (device_may_wakeup(dev))
1516 		serial_omap_enable_wakeup(up, false);
1517 
1518 	uart_resume_port(&serial_omap_reg, &up->port);
1519 
1520 	return 0;
1521 }
1522 #else
1523 #define serial_omap_prepare NULL
1524 #define serial_omap_complete NULL
1525 #endif /* CONFIG_PM_SLEEP */
1526 
1527 static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
1528 {
1529 	u32 mvr, scheme;
1530 	u16 revision, major, minor;
1531 
1532 	mvr = readl(up->port.membase + (UART_OMAP_MVER << up->port.regshift));
1533 
1534 	/* Check revision register scheme */
1535 	scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
1536 
1537 	switch (scheme) {
1538 	case 0: /* Legacy Scheme: OMAP2/3 */
1539 		/* MINOR_REV[0:4], MAJOR_REV[4:7] */
1540 		major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
1541 					OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
1542 		minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
1543 		break;
1544 	case 1:
1545 		/* New Scheme: OMAP4+ */
1546 		/* MINOR_REV[0:5], MAJOR_REV[8:10] */
1547 		major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
1548 					OMAP_UART_MVR_MAJ_SHIFT;
1549 		minor = (mvr & OMAP_UART_MVR_MIN_MASK);
1550 		break;
1551 	default:
1552 		dev_warn(up->dev,
1553 			"Unknown %s revision, defaulting to highest\n",
1554 			up->name);
1555 		/* highest possible revision */
1556 		major = 0xff;
1557 		minor = 0xff;
1558 	}
1559 
1560 	/* normalize revision for the driver */
1561 	revision = UART_BUILD_REVISION(major, minor);
1562 
1563 	switch (revision) {
1564 	case OMAP_UART_REV_46:
1565 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1566 				UART_ERRATA_i291_DMA_FORCEIDLE);
1567 		break;
1568 	case OMAP_UART_REV_52:
1569 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1570 				UART_ERRATA_i291_DMA_FORCEIDLE);
1571 		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1572 		break;
1573 	case OMAP_UART_REV_63:
1574 		up->errata |= UART_ERRATA_i202_MDR1_ACCESS;
1575 		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1576 		break;
1577 	default:
1578 		break;
1579 	}
1580 }
1581 
1582 static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
1583 {
1584 	struct omap_uart_port_info *omap_up_info;
1585 
1586 	omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
1587 	if (!omap_up_info)
1588 		return NULL; /* out of memory */
1589 
1590 	of_property_read_u32(dev->of_node, "clock-frequency",
1591 					 &omap_up_info->uartclk);
1592 	return omap_up_info;
1593 }
1594 
1595 static int serial_omap_probe_rs485(struct uart_omap_port *up,
1596 				   struct device_node *np)
1597 {
1598 	struct serial_rs485 *rs485conf = &up->rs485;
1599 	u32 rs485_delay[2];
1600 	enum of_gpio_flags flags;
1601 	int ret;
1602 
1603 	rs485conf->flags = 0;
1604 	up->rts_gpio = -EINVAL;
1605 
1606 	if (!np)
1607 		return 0;
1608 
1609 	if (of_property_read_bool(np, "rs485-rts-active-high"))
1610 		rs485conf->flags |= SER_RS485_RTS_ON_SEND;
1611 	else
1612 		rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
1613 
1614 	/* check for tx enable gpio */
1615 	up->rts_gpio = of_get_named_gpio_flags(np, "rts-gpio", 0, &flags);
1616 	if (gpio_is_valid(up->rts_gpio)) {
1617 		ret = gpio_request(up->rts_gpio, "omap-serial");
1618 		if (ret < 0)
1619 			return ret;
1620 		ret = gpio_direction_output(up->rts_gpio,
1621 					    flags & SER_RS485_RTS_AFTER_SEND);
1622 		if (ret < 0)
1623 			return ret;
1624 	} else if (up->rts_gpio == -EPROBE_DEFER) {
1625 		return -EPROBE_DEFER;
1626 	} else {
1627 		up->rts_gpio = -EINVAL;
1628 	}
1629 
1630 	if (of_property_read_u32_array(np, "rs485-rts-delay",
1631 				    rs485_delay, 2) == 0) {
1632 		rs485conf->delay_rts_before_send = rs485_delay[0];
1633 		rs485conf->delay_rts_after_send = rs485_delay[1];
1634 	}
1635 
1636 	if (of_property_read_bool(np, "rs485-rx-during-tx"))
1637 		rs485conf->flags |= SER_RS485_RX_DURING_TX;
1638 
1639 	if (of_property_read_bool(np, "linux,rs485-enabled-at-boot-time"))
1640 		rs485conf->flags |= SER_RS485_ENABLED;
1641 
1642 	return 0;
1643 }
1644 
1645 static int serial_omap_probe(struct platform_device *pdev)
1646 {
1647 	struct uart_omap_port	*up;
1648 	struct resource		*mem, *irq;
1649 	struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
1650 	int ret, uartirq = 0, wakeirq = 0;
1651 
1652 	/* The optional wakeirq may be specified in the board dts file */
1653 	if (pdev->dev.of_node) {
1654 		uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0);
1655 		if (!uartirq)
1656 			return -EPROBE_DEFER;
1657 		wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
1658 		omap_up_info = of_get_uart_port_info(&pdev->dev);
1659 		pdev->dev.platform_data = omap_up_info;
1660 	} else {
1661 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1662 		if (!irq) {
1663 			dev_err(&pdev->dev, "no irq resource?\n");
1664 			return -ENODEV;
1665 		}
1666 		uartirq = irq->start;
1667 	}
1668 
1669 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1670 	if (!mem) {
1671 		dev_err(&pdev->dev, "no mem resource?\n");
1672 		return -ENODEV;
1673 	}
1674 
1675 	if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
1676 				pdev->dev.driver->name)) {
1677 		dev_err(&pdev->dev, "memory region already claimed\n");
1678 		return -EBUSY;
1679 	}
1680 
1681 	if (gpio_is_valid(omap_up_info->DTR_gpio) &&
1682 	    omap_up_info->DTR_present) {
1683 		ret = gpio_request(omap_up_info->DTR_gpio, "omap-serial");
1684 		if (ret < 0)
1685 			return ret;
1686 		ret = gpio_direction_output(omap_up_info->DTR_gpio,
1687 					    omap_up_info->DTR_inverted);
1688 		if (ret < 0)
1689 			return ret;
1690 	}
1691 
1692 	up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
1693 	if (!up)
1694 		return -ENOMEM;
1695 
1696 	if (gpio_is_valid(omap_up_info->DTR_gpio) &&
1697 	    omap_up_info->DTR_present) {
1698 		up->DTR_gpio = omap_up_info->DTR_gpio;
1699 		up->DTR_inverted = omap_up_info->DTR_inverted;
1700 	} else
1701 		up->DTR_gpio = -EINVAL;
1702 	up->DTR_active = 0;
1703 
1704 	up->dev = &pdev->dev;
1705 	up->port.dev = &pdev->dev;
1706 	up->port.type = PORT_OMAP;
1707 	up->port.iotype = UPIO_MEM;
1708 	up->port.irq = uartirq;
1709 	up->wakeirq = wakeirq;
1710 	if (!up->wakeirq)
1711 		dev_info(up->port.dev, "no wakeirq for uart%d\n",
1712 			 up->port.line);
1713 
1714 	up->port.regshift = 2;
1715 	up->port.fifosize = 64;
1716 	up->port.ops = &serial_omap_pops;
1717 
1718 	if (pdev->dev.of_node)
1719 		up->port.line = of_alias_get_id(pdev->dev.of_node, "serial");
1720 	else
1721 		up->port.line = pdev->id;
1722 
1723 	if (up->port.line < 0) {
1724 		dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
1725 								up->port.line);
1726 		ret = -ENODEV;
1727 		goto err_port_line;
1728 	}
1729 
1730 	ret = serial_omap_probe_rs485(up, pdev->dev.of_node);
1731 	if (ret < 0)
1732 		goto err_rs485;
1733 
1734 	sprintf(up->name, "OMAP UART%d", up->port.line);
1735 	up->port.mapbase = mem->start;
1736 	up->port.membase = devm_ioremap(&pdev->dev, mem->start,
1737 						resource_size(mem));
1738 	if (!up->port.membase) {
1739 		dev_err(&pdev->dev, "can't ioremap UART\n");
1740 		ret = -ENOMEM;
1741 		goto err_ioremap;
1742 	}
1743 
1744 	up->port.flags = omap_up_info->flags;
1745 	up->port.uartclk = omap_up_info->uartclk;
1746 	if (!up->port.uartclk) {
1747 		up->port.uartclk = DEFAULT_CLK_SPEED;
1748 		dev_warn(&pdev->dev,
1749 			 "No clock speed specified: using default: %d\n",
1750 			 DEFAULT_CLK_SPEED);
1751 	}
1752 
1753 	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1754 	up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1755 	pm_qos_add_request(&up->pm_qos_request,
1756 		PM_QOS_CPU_DMA_LATENCY, up->latency);
1757 	serial_omap_uart_wq = create_singlethread_workqueue(up->name);
1758 	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
1759 
1760 	platform_set_drvdata(pdev, up);
1761 	if (omap_up_info->autosuspend_timeout == 0)
1762 		omap_up_info->autosuspend_timeout = -1;
1763 	device_init_wakeup(up->dev, true);
1764 	pm_runtime_use_autosuspend(&pdev->dev);
1765 	pm_runtime_set_autosuspend_delay(&pdev->dev,
1766 			omap_up_info->autosuspend_timeout);
1767 
1768 	pm_runtime_irq_safe(&pdev->dev);
1769 	pm_runtime_enable(&pdev->dev);
1770 
1771 	pm_runtime_get_sync(&pdev->dev);
1772 
1773 	omap_serial_fill_features_erratas(up);
1774 
1775 	ui[up->port.line] = up;
1776 	serial_omap_add_console_port(up);
1777 
1778 	ret = uart_add_one_port(&serial_omap_reg, &up->port);
1779 	if (ret != 0)
1780 		goto err_add_port;
1781 
1782 	pm_runtime_mark_last_busy(up->dev);
1783 	pm_runtime_put_autosuspend(up->dev);
1784 	return 0;
1785 
1786 err_add_port:
1787 	pm_runtime_put(&pdev->dev);
1788 	pm_runtime_disable(&pdev->dev);
1789 err_ioremap:
1790 err_rs485:
1791 err_port_line:
1792 	dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
1793 				pdev->id, __func__, ret);
1794 	return ret;
1795 }
1796 
1797 static int serial_omap_remove(struct platform_device *dev)
1798 {
1799 	struct uart_omap_port *up = platform_get_drvdata(dev);
1800 
1801 	pm_runtime_put_sync(up->dev);
1802 	pm_runtime_disable(up->dev);
1803 	uart_remove_one_port(&serial_omap_reg, &up->port);
1804 	pm_qos_remove_request(&up->pm_qos_request);
1805 	device_init_wakeup(&dev->dev, false);
1806 
1807 	return 0;
1808 }
1809 
1810 /*
1811  * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
1812  * The access to uart register after MDR1 Access
1813  * causes UART to corrupt data.
1814  *
1815  * Need a delay =
1816  * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
1817  * give 10 times as much
1818  */
1819 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
1820 {
1821 	u8 timeout = 255;
1822 
1823 	serial_out(up, UART_OMAP_MDR1, mdr1);
1824 	udelay(2);
1825 	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
1826 			UART_FCR_CLEAR_RCVR);
1827 	/*
1828 	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
1829 	 * TX_FIFO_E bit is 1.
1830 	 */
1831 	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
1832 				(UART_LSR_THRE | UART_LSR_DR))) {
1833 		timeout--;
1834 		if (!timeout) {
1835 			/* Should *never* happen. we warn and carry on */
1836 			dev_crit(up->dev, "Errata i202: timedout %x\n",
1837 						serial_in(up, UART_LSR));
1838 			break;
1839 		}
1840 		udelay(1);
1841 	}
1842 }
1843 
1844 #ifdef CONFIG_PM_RUNTIME
1845 static void serial_omap_restore_context(struct uart_omap_port *up)
1846 {
1847 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1848 		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
1849 	else
1850 		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
1851 
1852 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1853 	serial_out(up, UART_EFR, UART_EFR_ECB);
1854 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1855 	serial_out(up, UART_IER, 0x0);
1856 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1857 	serial_out(up, UART_DLL, up->dll);
1858 	serial_out(up, UART_DLM, up->dlh);
1859 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1860 	serial_out(up, UART_IER, up->ier);
1861 	serial_out(up, UART_FCR, up->fcr);
1862 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1863 	serial_out(up, UART_MCR, up->mcr);
1864 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1865 	serial_out(up, UART_OMAP_SCR, up->scr);
1866 	serial_out(up, UART_EFR, up->efr);
1867 	serial_out(up, UART_LCR, up->lcr);
1868 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1869 		serial_omap_mdr1_errataset(up, up->mdr1);
1870 	else
1871 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1872 	serial_out(up, UART_OMAP_WER, up->wer);
1873 }
1874 
1875 static int serial_omap_runtime_suspend(struct device *dev)
1876 {
1877 	struct uart_omap_port *up = dev_get_drvdata(dev);
1878 
1879 	if (!up)
1880 		return -EINVAL;
1881 
1882 	/*
1883 	* When using 'no_console_suspend', the console UART must not be
1884 	* suspended. Since driver suspend is managed by runtime suspend,
1885 	* preventing runtime suspend (by returning error) will keep device
1886 	* active during suspend.
1887 	*/
1888 	if (up->is_suspending && !console_suspend_enabled &&
1889 	    uart_console(&up->port))
1890 		return -EBUSY;
1891 
1892 	up->context_loss_cnt = serial_omap_get_context_loss_count(up);
1893 
1894 	serial_omap_enable_wakeup(up, true);
1895 
1896 	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1897 	schedule_work(&up->qos_work);
1898 
1899 	return 0;
1900 }
1901 
1902 static int serial_omap_runtime_resume(struct device *dev)
1903 {
1904 	struct uart_omap_port *up = dev_get_drvdata(dev);
1905 
1906 	int loss_cnt = serial_omap_get_context_loss_count(up);
1907 
1908 	serial_omap_enable_wakeup(up, false);
1909 
1910 	if (loss_cnt < 0) {
1911 		dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n",
1912 			loss_cnt);
1913 		serial_omap_restore_context(up);
1914 	} else if (up->context_loss_cnt != loss_cnt) {
1915 		serial_omap_restore_context(up);
1916 	}
1917 	up->latency = up->calc_latency;
1918 	schedule_work(&up->qos_work);
1919 
1920 	return 0;
1921 }
1922 #endif
1923 
1924 static const struct dev_pm_ops serial_omap_dev_pm_ops = {
1925 	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
1926 	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
1927 				serial_omap_runtime_resume, NULL)
1928 	.prepare        = serial_omap_prepare,
1929 	.complete       = serial_omap_complete,
1930 };
1931 
1932 #if defined(CONFIG_OF)
1933 static const struct of_device_id omap_serial_of_match[] = {
1934 	{ .compatible = "ti,omap2-uart" },
1935 	{ .compatible = "ti,omap3-uart" },
1936 	{ .compatible = "ti,omap4-uart" },
1937 	{},
1938 };
1939 MODULE_DEVICE_TABLE(of, omap_serial_of_match);
1940 #endif
1941 
1942 static struct platform_driver serial_omap_driver = {
1943 	.probe          = serial_omap_probe,
1944 	.remove         = serial_omap_remove,
1945 	.driver		= {
1946 		.name	= DRIVER_NAME,
1947 		.pm	= &serial_omap_dev_pm_ops,
1948 		.of_match_table = of_match_ptr(omap_serial_of_match),
1949 	},
1950 };
1951 
1952 static int __init serial_omap_init(void)
1953 {
1954 	int ret;
1955 
1956 	ret = uart_register_driver(&serial_omap_reg);
1957 	if (ret != 0)
1958 		return ret;
1959 	ret = platform_driver_register(&serial_omap_driver);
1960 	if (ret != 0)
1961 		uart_unregister_driver(&serial_omap_reg);
1962 	return ret;
1963 }
1964 
1965 static void __exit serial_omap_exit(void)
1966 {
1967 	platform_driver_unregister(&serial_omap_driver);
1968 	uart_unregister_driver(&serial_omap_reg);
1969 }
1970 
1971 module_init(serial_omap_init);
1972 module_exit(serial_omap_exit);
1973 
1974 MODULE_DESCRIPTION("OMAP High Speed UART driver");
1975 MODULE_LICENSE("GPL");
1976 MODULE_AUTHOR("Texas Instruments Inc");
1977