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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for OMAP-UART controller.
4  * Based on drivers/serial/8250.c
5  *
6  * Copyright (C) 2010 Texas Instruments.
7  *
8  * Authors:
9  *	Govindraj R	<govindraj.raja@ti.com>
10  *	Thara Gopinath	<thara@ti.com>
11  *
12  * Note: This driver is made separate from 8250 driver as we cannot
13  * over load 8250 driver with omap platform specific configuration for
14  * features like DMA, it makes easier to implement features like DMA and
15  * hardware flow control and software flow control configuration with
16  * this driver as required for the omap-platform.
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/serial_reg.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/tty.h>
26 #include <linux/tty_flip.h>
27 #include <linux/platform_device.h>
28 #include <linux/io.h>
29 #include <linux/clk.h>
30 #include <linux/serial_core.h>
31 #include <linux/irq.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_wakeirq.h>
34 #include <linux/of.h>
35 #include <linux/of_irq.h>
36 #include <linux/gpio/consumer.h>
37 #include <linux/platform_data/serial-omap.h>
38 
39 #define OMAP_MAX_HSUART_PORTS	10
40 
41 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
42 
43 #define OMAP_UART_REV_42 0x0402
44 #define OMAP_UART_REV_46 0x0406
45 #define OMAP_UART_REV_52 0x0502
46 #define OMAP_UART_REV_63 0x0603
47 
48 #define OMAP_UART_TX_WAKEUP_EN		BIT(7)
49 
50 /* Feature flags */
51 #define OMAP_UART_WER_HAS_TX_WAKEUP	BIT(0)
52 
53 #define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
54 #define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
55 
56 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz */
57 
58 /* SCR register bitmasks */
59 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
60 #define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK		(1 << 6)
61 #define OMAP_UART_SCR_TX_EMPTY			(1 << 3)
62 
63 /* FCR register bitmasks */
64 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK			(0x3 << 6)
65 #define OMAP_UART_FCR_TX_FIFO_TRIG_MASK			(0x3 << 4)
66 
67 /* MVR register bitmasks */
68 #define OMAP_UART_MVR_SCHEME_SHIFT	30
69 
70 #define OMAP_UART_LEGACY_MVR_MAJ_MASK	0xf0
71 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT	4
72 #define OMAP_UART_LEGACY_MVR_MIN_MASK	0x0f
73 
74 #define OMAP_UART_MVR_MAJ_MASK		0x700
75 #define OMAP_UART_MVR_MAJ_SHIFT		8
76 #define OMAP_UART_MVR_MIN_MASK		0x3f
77 
78 #define OMAP_UART_DMA_CH_FREE	-1
79 
80 #define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
81 #define OMAP_MODE13X_SPEED	230400
82 
83 /* WER = 0x7F
84  * Enable module level wakeup in WER reg
85  */
86 #define OMAP_UART_WER_MOD_WKUP	0x7F
87 
88 /* Enable XON/XOFF flow control on output */
89 #define OMAP_UART_SW_TX		0x08
90 
91 /* Enable XON/XOFF flow control on input */
92 #define OMAP_UART_SW_RX		0x02
93 
94 #define OMAP_UART_SW_CLR	0xF0
95 
96 #define OMAP_UART_TCR_TRIG	0x0F
97 
98 struct uart_omap_dma {
99 	u8			uart_dma_tx;
100 	u8			uart_dma_rx;
101 	int			rx_dma_channel;
102 	int			tx_dma_channel;
103 	dma_addr_t		rx_buf_dma_phys;
104 	dma_addr_t		tx_buf_dma_phys;
105 	unsigned int		uart_base;
106 	/*
107 	 * Buffer for rx dma. It is not required for tx because the buffer
108 	 * comes from port structure.
109 	 */
110 	unsigned char		*rx_buf;
111 	unsigned int		prev_rx_dma_pos;
112 	int			tx_buf_size;
113 	int			tx_dma_used;
114 	int			rx_dma_used;
115 	spinlock_t		tx_lock;
116 	spinlock_t		rx_lock;
117 	/* timer to poll activity on rx dma */
118 	struct timer_list	rx_timer;
119 	unsigned int		rx_buf_size;
120 	unsigned int		rx_poll_rate;
121 	unsigned int		rx_timeout;
122 };
123 
124 struct uart_omap_port {
125 	struct uart_port	port;
126 	struct uart_omap_dma	uart_dma;
127 	struct device		*dev;
128 	int			wakeirq;
129 
130 	unsigned char		ier;
131 	unsigned char		lcr;
132 	unsigned char		mcr;
133 	unsigned char		fcr;
134 	unsigned char		efr;
135 	unsigned char		dll;
136 	unsigned char		dlh;
137 	unsigned char		mdr1;
138 	unsigned char		scr;
139 	unsigned char		wer;
140 
141 	int			use_dma;
142 	/*
143 	 * Some bits in registers are cleared on a read, so they must
144 	 * be saved whenever the register is read, but the bits will not
145 	 * be immediately processed.
146 	 */
147 	unsigned int		lsr_break_flag;
148 	unsigned char		msr_saved_flags;
149 	char			name[20];
150 	unsigned long		port_activity;
151 	int			context_loss_cnt;
152 	u32			errata;
153 	u32			features;
154 
155 	struct gpio_desc	*rts_gpiod;
156 
157 	struct pm_qos_request	pm_qos_request;
158 	u32			latency;
159 	u32			calc_latency;
160 	struct work_struct	qos_work;
161 	bool			is_suspending;
162 
163 	unsigned int		rs485_tx_filter_count;
164 };
165 
166 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
167 
168 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
169 
170 /* Forward declaration of functions */
171 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
172 
serial_in(struct uart_omap_port * up,int offset)173 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
174 {
175 	offset <<= up->port.regshift;
176 	return readw(up->port.membase + offset);
177 }
178 
serial_out(struct uart_omap_port * up,int offset,int value)179 static inline void serial_out(struct uart_omap_port *up, int offset, int value)
180 {
181 	offset <<= up->port.regshift;
182 	writew(value, up->port.membase + offset);
183 }
184 
serial_omap_clear_fifos(struct uart_omap_port * up)185 static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
186 {
187 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
188 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
189 		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
190 	serial_out(up, UART_FCR, 0);
191 }
192 
193 #ifdef CONFIG_PM
serial_omap_get_context_loss_count(struct uart_omap_port * up)194 static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
195 {
196 	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
197 
198 	if (!pdata || !pdata->get_context_loss_count)
199 		return -EINVAL;
200 
201 	return pdata->get_context_loss_count(up->dev);
202 }
203 
204 /* REVISIT: Remove this when omap3 boots in device tree only mode */
serial_omap_enable_wakeup(struct uart_omap_port * up,bool enable)205 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
206 {
207 	struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
208 
209 	if (!pdata || !pdata->enable_wakeup)
210 		return;
211 
212 	pdata->enable_wakeup(up->dev, enable);
213 }
214 #endif /* CONFIG_PM */
215 
216 /*
217  * Calculate the absolute difference between the desired and actual baud
218  * rate for the given mode.
219  */
calculate_baud_abs_diff(struct uart_port * port,unsigned int baud,unsigned int mode)220 static inline int calculate_baud_abs_diff(struct uart_port *port,
221 				unsigned int baud, unsigned int mode)
222 {
223 	unsigned int n = port->uartclk / (mode * baud);
224 	int abs_diff;
225 
226 	if (n == 0)
227 		n = 1;
228 
229 	abs_diff = baud - (port->uartclk / (mode * n));
230 	if (abs_diff < 0)
231 		abs_diff = -abs_diff;
232 
233 	return abs_diff;
234 }
235 
236 /*
237  * serial_omap_baud_is_mode16 - check if baud rate is MODE16X
238  * @port: uart port info
239  * @baud: baudrate for which mode needs to be determined
240  *
241  * Returns true if baud rate is MODE16X and false if MODE13X
242  * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values,
243  * and Error Rates" determines modes not for all common baud rates.
244  * E.g. for 1000000 baud rate mode must be 16x, but according to that
245  * table it's determined as 13x.
246  */
247 static bool
serial_omap_baud_is_mode16(struct uart_port * port,unsigned int baud)248 serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
249 {
250 	int abs_diff_13 = calculate_baud_abs_diff(port, baud, 13);
251 	int abs_diff_16 = calculate_baud_abs_diff(port, baud, 16);
252 
253 	return (abs_diff_13 >= abs_diff_16);
254 }
255 
256 /*
257  * serial_omap_get_divisor - calculate divisor value
258  * @port: uart port info
259  * @baud: baudrate for which divisor needs to be calculated.
260  */
261 static unsigned int
serial_omap_get_divisor(struct uart_port * port,unsigned int baud)262 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
263 {
264 	unsigned int mode;
265 
266 	if (!serial_omap_baud_is_mode16(port, baud))
267 		mode = 13;
268 	else
269 		mode = 16;
270 	return port->uartclk/(mode * baud);
271 }
272 
serial_omap_enable_ms(struct uart_port * port)273 static void serial_omap_enable_ms(struct uart_port *port)
274 {
275 	struct uart_omap_port *up = to_uart_omap_port(port);
276 
277 	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);
278 
279 	pm_runtime_get_sync(up->dev);
280 	up->ier |= UART_IER_MSI;
281 	serial_out(up, UART_IER, up->ier);
282 	pm_runtime_mark_last_busy(up->dev);
283 	pm_runtime_put_autosuspend(up->dev);
284 }
285 
serial_omap_stop_tx(struct uart_port * port)286 static void serial_omap_stop_tx(struct uart_port *port)
287 {
288 	struct uart_omap_port *up = to_uart_omap_port(port);
289 	int res;
290 
291 	pm_runtime_get_sync(up->dev);
292 
293 	/* Handle RS-485 */
294 	if (port->rs485.flags & SER_RS485_ENABLED) {
295 		if (up->scr & OMAP_UART_SCR_TX_EMPTY) {
296 			/* THR interrupt is fired when both TX FIFO and TX
297 			 * shift register are empty. This means there's nothing
298 			 * left to transmit now, so make sure the THR interrupt
299 			 * is fired when TX FIFO is below the trigger level,
300 			 * disable THR interrupts and toggle the RS-485 GPIO
301 			 * data direction pin if needed.
302 			 */
303 			up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
304 			serial_out(up, UART_OMAP_SCR, up->scr);
305 			res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
306 				1 : 0;
307 			if (up->rts_gpiod &&
308 			    gpiod_get_value(up->rts_gpiod) != res) {
309 				if (port->rs485.delay_rts_after_send > 0)
310 					mdelay(
311 					port->rs485.delay_rts_after_send);
312 				gpiod_set_value(up->rts_gpiod, res);
313 			}
314 		} else {
315 			/* We're asked to stop, but there's still stuff in the
316 			 * UART FIFO, so make sure the THR interrupt is fired
317 			 * when both TX FIFO and TX shift register are empty.
318 			 * The next THR interrupt (if no transmission is started
319 			 * in the meantime) will indicate the end of a
320 			 * transmission. Therefore we _don't_ disable THR
321 			 * interrupts in this situation.
322 			 */
323 			up->scr |= OMAP_UART_SCR_TX_EMPTY;
324 			serial_out(up, UART_OMAP_SCR, up->scr);
325 			return;
326 		}
327 	}
328 
329 	if (up->ier & UART_IER_THRI) {
330 		up->ier &= ~UART_IER_THRI;
331 		serial_out(up, UART_IER, up->ier);
332 	}
333 
334 	pm_runtime_mark_last_busy(up->dev);
335 	pm_runtime_put_autosuspend(up->dev);
336 }
337 
serial_omap_stop_rx(struct uart_port * port)338 static void serial_omap_stop_rx(struct uart_port *port)
339 {
340 	struct uart_omap_port *up = to_uart_omap_port(port);
341 
342 	pm_runtime_get_sync(up->dev);
343 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
344 	up->port.read_status_mask &= ~UART_LSR_DR;
345 	serial_out(up, UART_IER, up->ier);
346 	pm_runtime_mark_last_busy(up->dev);
347 	pm_runtime_put_autosuspend(up->dev);
348 }
349 
transmit_chars(struct uart_omap_port * up,unsigned int lsr)350 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
351 {
352 	struct circ_buf *xmit = &up->port.state->xmit;
353 	int count;
354 
355 	if (up->port.x_char) {
356 		serial_out(up, UART_TX, up->port.x_char);
357 		up->port.icount.tx++;
358 		up->port.x_char = 0;
359 		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
360 		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
361 			up->rs485_tx_filter_count++;
362 
363 		return;
364 	}
365 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
366 		serial_omap_stop_tx(&up->port);
367 		return;
368 	}
369 	count = up->port.fifosize / 4;
370 	do {
371 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
372 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
373 		up->port.icount.tx++;
374 		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
375 		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
376 			up->rs485_tx_filter_count++;
377 
378 		if (uart_circ_empty(xmit))
379 			break;
380 	} while (--count > 0);
381 
382 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
383 		uart_write_wakeup(&up->port);
384 
385 	if (uart_circ_empty(xmit))
386 		serial_omap_stop_tx(&up->port);
387 }
388 
serial_omap_enable_ier_thri(struct uart_omap_port * up)389 static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
390 {
391 	if (!(up->ier & UART_IER_THRI)) {
392 		up->ier |= UART_IER_THRI;
393 		serial_out(up, UART_IER, up->ier);
394 	}
395 }
396 
serial_omap_start_tx(struct uart_port * port)397 static void serial_omap_start_tx(struct uart_port *port)
398 {
399 	struct uart_omap_port *up = to_uart_omap_port(port);
400 	int res;
401 
402 	pm_runtime_get_sync(up->dev);
403 
404 	/* Handle RS-485 */
405 	if (port->rs485.flags & SER_RS485_ENABLED) {
406 		/* Fire THR interrupts when FIFO is below trigger level */
407 		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
408 		serial_out(up, UART_OMAP_SCR, up->scr);
409 
410 		/* if rts not already enabled */
411 		res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
412 		if (up->rts_gpiod && gpiod_get_value(up->rts_gpiod) != res) {
413 			gpiod_set_value(up->rts_gpiod, res);
414 			if (port->rs485.delay_rts_before_send > 0)
415 				mdelay(port->rs485.delay_rts_before_send);
416 		}
417 	}
418 
419 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
420 	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
421 		up->rs485_tx_filter_count = 0;
422 
423 	serial_omap_enable_ier_thri(up);
424 	pm_runtime_mark_last_busy(up->dev);
425 	pm_runtime_put_autosuspend(up->dev);
426 }
427 
serial_omap_throttle(struct uart_port * port)428 static void serial_omap_throttle(struct uart_port *port)
429 {
430 	struct uart_omap_port *up = to_uart_omap_port(port);
431 	unsigned long flags;
432 
433 	pm_runtime_get_sync(up->dev);
434 	spin_lock_irqsave(&up->port.lock, flags);
435 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
436 	serial_out(up, UART_IER, up->ier);
437 	spin_unlock_irqrestore(&up->port.lock, flags);
438 	pm_runtime_mark_last_busy(up->dev);
439 	pm_runtime_put_autosuspend(up->dev);
440 }
441 
serial_omap_unthrottle(struct uart_port * port)442 static void serial_omap_unthrottle(struct uart_port *port)
443 {
444 	struct uart_omap_port *up = to_uart_omap_port(port);
445 	unsigned long flags;
446 
447 	pm_runtime_get_sync(up->dev);
448 	spin_lock_irqsave(&up->port.lock, flags);
449 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
450 	serial_out(up, UART_IER, up->ier);
451 	spin_unlock_irqrestore(&up->port.lock, flags);
452 	pm_runtime_mark_last_busy(up->dev);
453 	pm_runtime_put_autosuspend(up->dev);
454 }
455 
check_modem_status(struct uart_omap_port * up)456 static unsigned int check_modem_status(struct uart_omap_port *up)
457 {
458 	unsigned int status;
459 
460 	status = serial_in(up, UART_MSR);
461 	status |= up->msr_saved_flags;
462 	up->msr_saved_flags = 0;
463 	if ((status & UART_MSR_ANY_DELTA) == 0)
464 		return status;
465 
466 	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
467 	    up->port.state != NULL) {
468 		if (status & UART_MSR_TERI)
469 			up->port.icount.rng++;
470 		if (status & UART_MSR_DDSR)
471 			up->port.icount.dsr++;
472 		if (status & UART_MSR_DDCD)
473 			uart_handle_dcd_change
474 				(&up->port, status & UART_MSR_DCD);
475 		if (status & UART_MSR_DCTS)
476 			uart_handle_cts_change
477 				(&up->port, status & UART_MSR_CTS);
478 		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
479 	}
480 
481 	return status;
482 }
483 
serial_omap_rlsi(struct uart_omap_port * up,unsigned int lsr)484 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
485 {
486 	unsigned int flag;
487 
488 	/*
489 	 * Read one data character out to avoid stalling the receiver according
490 	 * to the table 23-246 of the omap4 TRM.
491 	 */
492 	if (likely(lsr & UART_LSR_DR)) {
493 		serial_in(up, UART_RX);
494 		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
495 		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
496 		    up->rs485_tx_filter_count)
497 			up->rs485_tx_filter_count--;
498 	}
499 
500 	up->port.icount.rx++;
501 	flag = TTY_NORMAL;
502 
503 	if (lsr & UART_LSR_BI) {
504 		flag = TTY_BREAK;
505 		lsr &= ~(UART_LSR_FE | UART_LSR_PE);
506 		up->port.icount.brk++;
507 		/*
508 		 * We do the SysRQ and SAK checking
509 		 * here because otherwise the break
510 		 * may get masked by ignore_status_mask
511 		 * or read_status_mask.
512 		 */
513 		if (uart_handle_break(&up->port))
514 			return;
515 
516 	}
517 
518 	if (lsr & UART_LSR_PE) {
519 		flag = TTY_PARITY;
520 		up->port.icount.parity++;
521 	}
522 
523 	if (lsr & UART_LSR_FE) {
524 		flag = TTY_FRAME;
525 		up->port.icount.frame++;
526 	}
527 
528 	if (lsr & UART_LSR_OE)
529 		up->port.icount.overrun++;
530 
531 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
532 	if (up->port.line == up->port.cons->index) {
533 		/* Recover the break flag from console xmit */
534 		lsr |= up->lsr_break_flag;
535 	}
536 #endif
537 	uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag);
538 }
539 
serial_omap_rdi(struct uart_omap_port * up,unsigned int lsr)540 static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
541 {
542 	unsigned char ch = 0;
543 	unsigned int flag;
544 
545 	if (!(lsr & UART_LSR_DR))
546 		return;
547 
548 	ch = serial_in(up, UART_RX);
549 	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
550 	    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
551 	    up->rs485_tx_filter_count) {
552 		up->rs485_tx_filter_count--;
553 		return;
554 	}
555 
556 	flag = TTY_NORMAL;
557 	up->port.icount.rx++;
558 
559 	if (uart_handle_sysrq_char(&up->port, ch))
560 		return;
561 
562 	uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
563 }
564 
565 /**
566  * serial_omap_irq() - This handles the interrupt from one port
567  * @irq: uart port irq number
568  * @dev_id: uart port info
569  */
serial_omap_irq(int irq,void * dev_id)570 static irqreturn_t serial_omap_irq(int irq, void *dev_id)
571 {
572 	struct uart_omap_port *up = dev_id;
573 	unsigned int iir, lsr;
574 	unsigned int type;
575 	irqreturn_t ret = IRQ_NONE;
576 	int max_count = 256;
577 
578 	spin_lock(&up->port.lock);
579 	pm_runtime_get_sync(up->dev);
580 
581 	do {
582 		iir = serial_in(up, UART_IIR);
583 		if (iir & UART_IIR_NO_INT)
584 			break;
585 
586 		ret = IRQ_HANDLED;
587 		lsr = serial_in(up, UART_LSR);
588 
589 		/* extract IRQ type from IIR register */
590 		type = iir & 0x3e;
591 
592 		switch (type) {
593 		case UART_IIR_MSI:
594 			check_modem_status(up);
595 			break;
596 		case UART_IIR_THRI:
597 			transmit_chars(up, lsr);
598 			break;
599 		case UART_IIR_RX_TIMEOUT:
600 		case UART_IIR_RDI:
601 			serial_omap_rdi(up, lsr);
602 			break;
603 		case UART_IIR_RLSI:
604 			serial_omap_rlsi(up, lsr);
605 			break;
606 		case UART_IIR_CTS_RTS_DSR:
607 			/* simply try again */
608 			break;
609 		case UART_IIR_XOFF:
610 		default:
611 			break;
612 		}
613 	} while (max_count--);
614 
615 	spin_unlock(&up->port.lock);
616 
617 	tty_flip_buffer_push(&up->port.state->port);
618 
619 	pm_runtime_mark_last_busy(up->dev);
620 	pm_runtime_put_autosuspend(up->dev);
621 	up->port_activity = jiffies;
622 
623 	return ret;
624 }
625 
serial_omap_tx_empty(struct uart_port * port)626 static unsigned int serial_omap_tx_empty(struct uart_port *port)
627 {
628 	struct uart_omap_port *up = to_uart_omap_port(port);
629 	unsigned long flags = 0;
630 	unsigned int ret = 0;
631 
632 	pm_runtime_get_sync(up->dev);
633 	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
634 	spin_lock_irqsave(&up->port.lock, flags);
635 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
636 	spin_unlock_irqrestore(&up->port.lock, flags);
637 	pm_runtime_mark_last_busy(up->dev);
638 	pm_runtime_put_autosuspend(up->dev);
639 	return ret;
640 }
641 
serial_omap_get_mctrl(struct uart_port * port)642 static unsigned int serial_omap_get_mctrl(struct uart_port *port)
643 {
644 	struct uart_omap_port *up = to_uart_omap_port(port);
645 	unsigned int status;
646 	unsigned int ret = 0;
647 
648 	pm_runtime_get_sync(up->dev);
649 	status = check_modem_status(up);
650 	pm_runtime_mark_last_busy(up->dev);
651 	pm_runtime_put_autosuspend(up->dev);
652 
653 	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);
654 
655 	if (status & UART_MSR_DCD)
656 		ret |= TIOCM_CAR;
657 	if (status & UART_MSR_RI)
658 		ret |= TIOCM_RNG;
659 	if (status & UART_MSR_DSR)
660 		ret |= TIOCM_DSR;
661 	if (status & UART_MSR_CTS)
662 		ret |= TIOCM_CTS;
663 	return ret;
664 }
665 
serial_omap_set_mctrl(struct uart_port * port,unsigned int mctrl)666 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
667 {
668 	struct uart_omap_port *up = to_uart_omap_port(port);
669 	unsigned char mcr = 0, old_mcr, lcr;
670 
671 	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
672 	if (mctrl & TIOCM_RTS)
673 		mcr |= UART_MCR_RTS;
674 	if (mctrl & TIOCM_DTR)
675 		mcr |= UART_MCR_DTR;
676 	if (mctrl & TIOCM_OUT1)
677 		mcr |= UART_MCR_OUT1;
678 	if (mctrl & TIOCM_OUT2)
679 		mcr |= UART_MCR_OUT2;
680 	if (mctrl & TIOCM_LOOP)
681 		mcr |= UART_MCR_LOOP;
682 
683 	pm_runtime_get_sync(up->dev);
684 	old_mcr = serial_in(up, UART_MCR);
685 	old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 |
686 		     UART_MCR_DTR | UART_MCR_RTS);
687 	up->mcr = old_mcr | mcr;
688 	serial_out(up, UART_MCR, up->mcr);
689 
690 	/* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */
691 	lcr = serial_in(up, UART_LCR);
692 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
693 	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
694 		up->efr |= UART_EFR_RTS;
695 	else
696 		up->efr &= ~UART_EFR_RTS;
697 	serial_out(up, UART_EFR, up->efr);
698 	serial_out(up, UART_LCR, lcr);
699 
700 	pm_runtime_mark_last_busy(up->dev);
701 	pm_runtime_put_autosuspend(up->dev);
702 }
703 
serial_omap_break_ctl(struct uart_port * port,int break_state)704 static void serial_omap_break_ctl(struct uart_port *port, int break_state)
705 {
706 	struct uart_omap_port *up = to_uart_omap_port(port);
707 	unsigned long flags = 0;
708 
709 	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
710 	pm_runtime_get_sync(up->dev);
711 	spin_lock_irqsave(&up->port.lock, flags);
712 	if (break_state == -1)
713 		up->lcr |= UART_LCR_SBC;
714 	else
715 		up->lcr &= ~UART_LCR_SBC;
716 	serial_out(up, UART_LCR, up->lcr);
717 	spin_unlock_irqrestore(&up->port.lock, flags);
718 	pm_runtime_mark_last_busy(up->dev);
719 	pm_runtime_put_autosuspend(up->dev);
720 }
721 
serial_omap_startup(struct uart_port * port)722 static int serial_omap_startup(struct uart_port *port)
723 {
724 	struct uart_omap_port *up = to_uart_omap_port(port);
725 	unsigned long flags = 0;
726 	int retval;
727 
728 	/*
729 	 * Allocate the IRQ
730 	 */
731 	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
732 				up->name, up);
733 	if (retval)
734 		return retval;
735 
736 	/* Optional wake-up IRQ */
737 	if (up->wakeirq) {
738 		retval = dev_pm_set_dedicated_wake_irq(up->dev, up->wakeirq);
739 		if (retval) {
740 			free_irq(up->port.irq, up);
741 			return retval;
742 		}
743 	}
744 
745 	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
746 
747 	pm_runtime_get_sync(up->dev);
748 	/*
749 	 * Clear the FIFO buffers and disable them.
750 	 * (they will be reenabled in set_termios())
751 	 */
752 	serial_omap_clear_fifos(up);
753 
754 	/*
755 	 * Clear the interrupt registers.
756 	 */
757 	(void) serial_in(up, UART_LSR);
758 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
759 		(void) serial_in(up, UART_RX);
760 	(void) serial_in(up, UART_IIR);
761 	(void) serial_in(up, UART_MSR);
762 
763 	/*
764 	 * Now, initialize the UART
765 	 */
766 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
767 	spin_lock_irqsave(&up->port.lock, flags);
768 	/*
769 	 * Most PC uarts need OUT2 raised to enable interrupts.
770 	 */
771 	up->port.mctrl |= TIOCM_OUT2;
772 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
773 	spin_unlock_irqrestore(&up->port.lock, flags);
774 
775 	up->msr_saved_flags = 0;
776 	/*
777 	 * Finally, enable interrupts. Note: Modem status interrupts
778 	 * are set via set_termios(), which will be occurring imminently
779 	 * anyway, so we don't enable them here.
780 	 */
781 	up->ier = UART_IER_RLSI | UART_IER_RDI;
782 	serial_out(up, UART_IER, up->ier);
783 
784 	/* Enable module level wake up */
785 	up->wer = OMAP_UART_WER_MOD_WKUP;
786 	if (up->features & OMAP_UART_WER_HAS_TX_WAKEUP)
787 		up->wer |= OMAP_UART_TX_WAKEUP_EN;
788 
789 	serial_out(up, UART_OMAP_WER, up->wer);
790 
791 	pm_runtime_mark_last_busy(up->dev);
792 	pm_runtime_put_autosuspend(up->dev);
793 	up->port_activity = jiffies;
794 	return 0;
795 }
796 
serial_omap_shutdown(struct uart_port * port)797 static void serial_omap_shutdown(struct uart_port *port)
798 {
799 	struct uart_omap_port *up = to_uart_omap_port(port);
800 	unsigned long flags = 0;
801 
802 	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);
803 
804 	pm_runtime_get_sync(up->dev);
805 	/*
806 	 * Disable interrupts from this port
807 	 */
808 	up->ier = 0;
809 	serial_out(up, UART_IER, 0);
810 
811 	spin_lock_irqsave(&up->port.lock, flags);
812 	up->port.mctrl &= ~TIOCM_OUT2;
813 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
814 	spin_unlock_irqrestore(&up->port.lock, flags);
815 
816 	/*
817 	 * Disable break condition and FIFOs
818 	 */
819 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
820 	serial_omap_clear_fifos(up);
821 
822 	/*
823 	 * Read data port to reset things, and then free the irq
824 	 */
825 	if (serial_in(up, UART_LSR) & UART_LSR_DR)
826 		(void) serial_in(up, UART_RX);
827 
828 	pm_runtime_mark_last_busy(up->dev);
829 	pm_runtime_put_autosuspend(up->dev);
830 	free_irq(up->port.irq, up);
831 	dev_pm_clear_wake_irq(up->dev);
832 }
833 
serial_omap_uart_qos_work(struct work_struct * work)834 static void serial_omap_uart_qos_work(struct work_struct *work)
835 {
836 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
837 						qos_work);
838 
839 	cpu_latency_qos_update_request(&up->pm_qos_request, up->latency);
840 }
841 
842 static void
serial_omap_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)843 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
844 			struct ktermios *old)
845 {
846 	struct uart_omap_port *up = to_uart_omap_port(port);
847 	unsigned char cval = 0;
848 	unsigned long flags = 0;
849 	unsigned int baud, quot;
850 
851 	switch (termios->c_cflag & CSIZE) {
852 	case CS5:
853 		cval = UART_LCR_WLEN5;
854 		break;
855 	case CS6:
856 		cval = UART_LCR_WLEN6;
857 		break;
858 	case CS7:
859 		cval = UART_LCR_WLEN7;
860 		break;
861 	default:
862 	case CS8:
863 		cval = UART_LCR_WLEN8;
864 		break;
865 	}
866 
867 	if (termios->c_cflag & CSTOPB)
868 		cval |= UART_LCR_STOP;
869 	if (termios->c_cflag & PARENB)
870 		cval |= UART_LCR_PARITY;
871 	if (!(termios->c_cflag & PARODD))
872 		cval |= UART_LCR_EPAR;
873 	if (termios->c_cflag & CMSPAR)
874 		cval |= UART_LCR_SPAR;
875 
876 	/*
877 	 * Ask the core to calculate the divisor for us.
878 	 */
879 
880 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
881 	quot = serial_omap_get_divisor(port, baud);
882 
883 	/* calculate wakeup latency constraint */
884 	up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
885 	up->latency = up->calc_latency;
886 	schedule_work(&up->qos_work);
887 
888 	up->dll = quot & 0xff;
889 	up->dlh = quot >> 8;
890 	up->mdr1 = UART_OMAP_MDR1_DISABLE;
891 
892 	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
893 			UART_FCR_ENABLE_FIFO;
894 
895 	/*
896 	 * Ok, we're now changing the port state. Do it with
897 	 * interrupts disabled.
898 	 */
899 	pm_runtime_get_sync(up->dev);
900 	spin_lock_irqsave(&up->port.lock, flags);
901 
902 	/*
903 	 * Update the per-port timeout.
904 	 */
905 	uart_update_timeout(port, termios->c_cflag, baud);
906 
907 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
908 	if (termios->c_iflag & INPCK)
909 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
910 	if (termios->c_iflag & (BRKINT | PARMRK))
911 		up->port.read_status_mask |= UART_LSR_BI;
912 
913 	/*
914 	 * Characters to ignore
915 	 */
916 	up->port.ignore_status_mask = 0;
917 	if (termios->c_iflag & IGNPAR)
918 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
919 	if (termios->c_iflag & IGNBRK) {
920 		up->port.ignore_status_mask |= UART_LSR_BI;
921 		/*
922 		 * If we're ignoring parity and break indicators,
923 		 * ignore overruns too (for real raw support).
924 		 */
925 		if (termios->c_iflag & IGNPAR)
926 			up->port.ignore_status_mask |= UART_LSR_OE;
927 	}
928 
929 	/*
930 	 * ignore all characters if CREAD is not set
931 	 */
932 	if ((termios->c_cflag & CREAD) == 0)
933 		up->port.ignore_status_mask |= UART_LSR_DR;
934 
935 	/*
936 	 * Modem status interrupts
937 	 */
938 	up->ier &= ~UART_IER_MSI;
939 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
940 		up->ier |= UART_IER_MSI;
941 	serial_out(up, UART_IER, up->ier);
942 	serial_out(up, UART_LCR, cval);		/* reset DLAB */
943 	up->lcr = cval;
944 	up->scr = 0;
945 
946 	/* FIFOs and DMA Settings */
947 
948 	/* FCR can be changed only when the
949 	 * baud clock is not running
950 	 * DLL_REG and DLH_REG set to 0.
951 	 */
952 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
953 	serial_out(up, UART_DLL, 0);
954 	serial_out(up, UART_DLM, 0);
955 	serial_out(up, UART_LCR, 0);
956 
957 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
958 
959 	up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB;
960 	up->efr &= ~UART_EFR_SCD;
961 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
962 
963 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
964 	up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR;
965 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
966 	/* FIFO ENABLE, DMA MODE */
967 
968 	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
969 	/*
970 	 * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK
971 	 * sets Enables the granularity of 1 for TRIGGER RX
972 	 * level. Along with setting RX FIFO trigger level
973 	 * to 1 (as noted below, 16 characters) and TLR[3:0]
974 	 * to zero this will result RX FIFO threshold level
975 	 * to 1 character, instead of 16 as noted in comment
976 	 * below.
977 	 */
978 
979 	/* Set receive FIFO threshold to 16 characters and
980 	 * transmit FIFO threshold to 32 spaces
981 	 */
982 	up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
983 	up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
984 	up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 |
985 		UART_FCR_ENABLE_FIFO;
986 
987 	serial_out(up, UART_FCR, up->fcr);
988 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
989 
990 	serial_out(up, UART_OMAP_SCR, up->scr);
991 
992 	/* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */
993 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
994 	serial_out(up, UART_MCR, up->mcr);
995 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
996 	serial_out(up, UART_EFR, up->efr);
997 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
998 
999 	/* Protocol, Baud Rate, and Interrupt Settings */
1000 
1001 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1002 		serial_omap_mdr1_errataset(up, up->mdr1);
1003 	else
1004 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1005 
1006 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1007 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1008 
1009 	serial_out(up, UART_LCR, 0);
1010 	serial_out(up, UART_IER, 0);
1011 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1012 
1013 	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
1014 	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */
1015 
1016 	serial_out(up, UART_LCR, 0);
1017 	serial_out(up, UART_IER, up->ier);
1018 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1019 
1020 	serial_out(up, UART_EFR, up->efr);
1021 	serial_out(up, UART_LCR, cval);
1022 
1023 	if (!serial_omap_baud_is_mode16(port, baud))
1024 		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
1025 	else
1026 		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
1027 
1028 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1029 		serial_omap_mdr1_errataset(up, up->mdr1);
1030 	else
1031 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1032 
1033 	/* Configure flow control */
1034 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1035 
1036 	/* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */
1037 	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
1038 	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
1039 
1040 	/* Enable access to TCR/TLR */
1041 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1042 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1043 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
1044 
1045 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
1046 
1047 	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
1048 
1049 	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
1050 		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
1051 		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1052 		up->efr |= UART_EFR_CTS;
1053 	} else {
1054 		/* Disable AUTORTS and AUTOCTS */
1055 		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
1056 	}
1057 
1058 	if (up->port.flags & UPF_SOFT_FLOW) {
1059 		/* clear SW control mode bits */
1060 		up->efr &= OMAP_UART_SW_CLR;
1061 
1062 		/*
1063 		 * IXON Flag:
1064 		 * Enable XON/XOFF flow control on input.
1065 		 * Receiver compares XON1, XOFF1.
1066 		 */
1067 		if (termios->c_iflag & IXON)
1068 			up->efr |= OMAP_UART_SW_RX;
1069 
1070 		/*
1071 		 * IXOFF Flag:
1072 		 * Enable XON/XOFF flow control on output.
1073 		 * Transmit XON1, XOFF1
1074 		 */
1075 		if (termios->c_iflag & IXOFF) {
1076 			up->port.status |= UPSTAT_AUTOXOFF;
1077 			up->efr |= OMAP_UART_SW_TX;
1078 		}
1079 
1080 		/*
1081 		 * IXANY Flag:
1082 		 * Enable any character to restart output.
1083 		 * Operation resumes after receiving any
1084 		 * character after recognition of the XOFF character
1085 		 */
1086 		if (termios->c_iflag & IXANY)
1087 			up->mcr |= UART_MCR_XONANY;
1088 		else
1089 			up->mcr &= ~UART_MCR_XONANY;
1090 	}
1091 	serial_out(up, UART_MCR, up->mcr);
1092 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1093 	serial_out(up, UART_EFR, up->efr);
1094 	serial_out(up, UART_LCR, up->lcr);
1095 
1096 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
1097 
1098 	spin_unlock_irqrestore(&up->port.lock, flags);
1099 	pm_runtime_mark_last_busy(up->dev);
1100 	pm_runtime_put_autosuspend(up->dev);
1101 	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
1102 }
1103 
1104 static void
serial_omap_pm(struct uart_port * port,unsigned int state,unsigned int oldstate)1105 serial_omap_pm(struct uart_port *port, unsigned int state,
1106 	       unsigned int oldstate)
1107 {
1108 	struct uart_omap_port *up = to_uart_omap_port(port);
1109 	unsigned char efr;
1110 
1111 	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);
1112 
1113 	pm_runtime_get_sync(up->dev);
1114 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1115 	efr = serial_in(up, UART_EFR);
1116 	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
1117 	serial_out(up, UART_LCR, 0);
1118 
1119 	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
1120 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1121 	serial_out(up, UART_EFR, efr);
1122 	serial_out(up, UART_LCR, 0);
1123 
1124 	pm_runtime_mark_last_busy(up->dev);
1125 	pm_runtime_put_autosuspend(up->dev);
1126 }
1127 
serial_omap_release_port(struct uart_port * port)1128 static void serial_omap_release_port(struct uart_port *port)
1129 {
1130 	dev_dbg(port->dev, "serial_omap_release_port+\n");
1131 }
1132 
serial_omap_request_port(struct uart_port * port)1133 static int serial_omap_request_port(struct uart_port *port)
1134 {
1135 	dev_dbg(port->dev, "serial_omap_request_port+\n");
1136 	return 0;
1137 }
1138 
serial_omap_config_port(struct uart_port * port,int flags)1139 static void serial_omap_config_port(struct uart_port *port, int flags)
1140 {
1141 	struct uart_omap_port *up = to_uart_omap_port(port);
1142 
1143 	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
1144 							up->port.line);
1145 	up->port.type = PORT_OMAP;
1146 	up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW;
1147 }
1148 
1149 static int
serial_omap_verify_port(struct uart_port * port,struct serial_struct * ser)1150 serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
1151 {
1152 	/* we don't want the core code to modify any port params */
1153 	dev_dbg(port->dev, "serial_omap_verify_port+\n");
1154 	return -EINVAL;
1155 }
1156 
1157 static const char *
serial_omap_type(struct uart_port * port)1158 serial_omap_type(struct uart_port *port)
1159 {
1160 	struct uart_omap_port *up = to_uart_omap_port(port);
1161 
1162 	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
1163 	return up->name;
1164 }
1165 
1166 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1167 
wait_for_xmitr(struct uart_omap_port * up)1168 static void __maybe_unused wait_for_xmitr(struct uart_omap_port *up)
1169 {
1170 	unsigned int status, tmout = 10000;
1171 
1172 	/* Wait up to 10ms for the character(s) to be sent. */
1173 	do {
1174 		status = serial_in(up, UART_LSR);
1175 
1176 		if (status & UART_LSR_BI)
1177 			up->lsr_break_flag = UART_LSR_BI;
1178 
1179 		if (--tmout == 0)
1180 			break;
1181 		udelay(1);
1182 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
1183 
1184 	/* Wait up to 1s for flow control if necessary */
1185 	if (up->port.flags & UPF_CONS_FLOW) {
1186 		tmout = 1000000;
1187 		for (tmout = 1000000; tmout; tmout--) {
1188 			unsigned int msr = serial_in(up, UART_MSR);
1189 
1190 			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1191 			if (msr & UART_MSR_CTS)
1192 				break;
1193 
1194 			udelay(1);
1195 		}
1196 	}
1197 }
1198 
1199 #ifdef CONFIG_CONSOLE_POLL
1200 
serial_omap_poll_put_char(struct uart_port * port,unsigned char ch)1201 static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
1202 {
1203 	struct uart_omap_port *up = to_uart_omap_port(port);
1204 
1205 	pm_runtime_get_sync(up->dev);
1206 	wait_for_xmitr(up);
1207 	serial_out(up, UART_TX, ch);
1208 	pm_runtime_mark_last_busy(up->dev);
1209 	pm_runtime_put_autosuspend(up->dev);
1210 }
1211 
serial_omap_poll_get_char(struct uart_port * port)1212 static int serial_omap_poll_get_char(struct uart_port *port)
1213 {
1214 	struct uart_omap_port *up = to_uart_omap_port(port);
1215 	unsigned int status;
1216 
1217 	pm_runtime_get_sync(up->dev);
1218 	status = serial_in(up, UART_LSR);
1219 	if (!(status & UART_LSR_DR)) {
1220 		status = NO_POLL_CHAR;
1221 		goto out;
1222 	}
1223 
1224 	status = serial_in(up, UART_RX);
1225 
1226 out:
1227 	pm_runtime_mark_last_busy(up->dev);
1228 	pm_runtime_put_autosuspend(up->dev);
1229 
1230 	return status;
1231 }
1232 
1233 #endif /* CONFIG_CONSOLE_POLL */
1234 
1235 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
1236 
1237 #ifdef CONFIG_SERIAL_EARLYCON
omap_serial_early_in(struct uart_port * port,int offset)1238 static unsigned int omap_serial_early_in(struct uart_port *port, int offset)
1239 {
1240 	offset <<= port->regshift;
1241 	return readw(port->membase + offset);
1242 }
1243 
omap_serial_early_out(struct uart_port * port,int offset,int value)1244 static void omap_serial_early_out(struct uart_port *port, int offset,
1245 				  int value)
1246 {
1247 	offset <<= port->regshift;
1248 	writew(value, port->membase + offset);
1249 }
1250 
omap_serial_early_putc(struct uart_port * port,int c)1251 static void omap_serial_early_putc(struct uart_port *port, int c)
1252 {
1253 	unsigned int status;
1254 
1255 	for (;;) {
1256 		status = omap_serial_early_in(port, UART_LSR);
1257 		if ((status & BOTH_EMPTY) == BOTH_EMPTY)
1258 			break;
1259 		cpu_relax();
1260 	}
1261 	omap_serial_early_out(port, UART_TX, c);
1262 }
1263 
early_omap_serial_write(struct console * console,const char * s,unsigned int count)1264 static void early_omap_serial_write(struct console *console, const char *s,
1265 				    unsigned int count)
1266 {
1267 	struct earlycon_device *device = console->data;
1268 	struct uart_port *port = &device->port;
1269 
1270 	uart_console_write(port, s, count, omap_serial_early_putc);
1271 }
1272 
early_omap_serial_setup(struct earlycon_device * device,const char * options)1273 static int __init early_omap_serial_setup(struct earlycon_device *device,
1274 					  const char *options)
1275 {
1276 	struct uart_port *port = &device->port;
1277 
1278 	if (!(device->port.membase || device->port.iobase))
1279 		return -ENODEV;
1280 
1281 	port->regshift = 2;
1282 	device->con->write = early_omap_serial_write;
1283 	return 0;
1284 }
1285 
1286 OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup);
1287 OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup);
1288 OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup);
1289 #endif /* CONFIG_SERIAL_EARLYCON */
1290 
1291 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
1292 
1293 static struct uart_driver serial_omap_reg;
1294 
serial_omap_console_putchar(struct uart_port * port,int ch)1295 static void serial_omap_console_putchar(struct uart_port *port, int ch)
1296 {
1297 	struct uart_omap_port *up = to_uart_omap_port(port);
1298 
1299 	wait_for_xmitr(up);
1300 	serial_out(up, UART_TX, ch);
1301 }
1302 
1303 static void
serial_omap_console_write(struct console * co,const char * s,unsigned int count)1304 serial_omap_console_write(struct console *co, const char *s,
1305 		unsigned int count)
1306 {
1307 	struct uart_omap_port *up = serial_omap_console_ports[co->index];
1308 	unsigned long flags;
1309 	unsigned int ier;
1310 	int locked = 1;
1311 
1312 	pm_runtime_get_sync(up->dev);
1313 
1314 	local_irq_save(flags);
1315 	if (up->port.sysrq)
1316 		locked = 0;
1317 	else if (oops_in_progress)
1318 		locked = spin_trylock(&up->port.lock);
1319 	else
1320 		spin_lock(&up->port.lock);
1321 
1322 	/*
1323 	 * First save the IER then disable the interrupts
1324 	 */
1325 	ier = serial_in(up, UART_IER);
1326 	serial_out(up, UART_IER, 0);
1327 
1328 	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
1329 
1330 	/*
1331 	 * Finally, wait for transmitter to become empty
1332 	 * and restore the IER
1333 	 */
1334 	wait_for_xmitr(up);
1335 	serial_out(up, UART_IER, ier);
1336 	/*
1337 	 * The receive handling will happen properly because the
1338 	 * receive ready bit will still be set; it is not cleared
1339 	 * on read.  However, modem control will not, we must
1340 	 * call it if we have saved something in the saved flags
1341 	 * while processing with interrupts off.
1342 	 */
1343 	if (up->msr_saved_flags)
1344 		check_modem_status(up);
1345 
1346 	pm_runtime_mark_last_busy(up->dev);
1347 	pm_runtime_put_autosuspend(up->dev);
1348 	if (locked)
1349 		spin_unlock(&up->port.lock);
1350 	local_irq_restore(flags);
1351 }
1352 
1353 static int __init
serial_omap_console_setup(struct console * co,char * options)1354 serial_omap_console_setup(struct console *co, char *options)
1355 {
1356 	struct uart_omap_port *up;
1357 	int baud = 115200;
1358 	int bits = 8;
1359 	int parity = 'n';
1360 	int flow = 'n';
1361 
1362 	if (serial_omap_console_ports[co->index] == NULL)
1363 		return -ENODEV;
1364 	up = serial_omap_console_ports[co->index];
1365 
1366 	if (options)
1367 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1368 
1369 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
1370 }
1371 
1372 static struct console serial_omap_console = {
1373 	.name		= OMAP_SERIAL_NAME,
1374 	.write		= serial_omap_console_write,
1375 	.device		= uart_console_device,
1376 	.setup		= serial_omap_console_setup,
1377 	.flags		= CON_PRINTBUFFER,
1378 	.index		= -1,
1379 	.data		= &serial_omap_reg,
1380 };
1381 
serial_omap_add_console_port(struct uart_omap_port * up)1382 static void serial_omap_add_console_port(struct uart_omap_port *up)
1383 {
1384 	serial_omap_console_ports[up->port.line] = up;
1385 }
1386 
1387 #define OMAP_CONSOLE	(&serial_omap_console)
1388 
1389 #else
1390 
1391 #define OMAP_CONSOLE	NULL
1392 
serial_omap_add_console_port(struct uart_omap_port * up)1393 static inline void serial_omap_add_console_port(struct uart_omap_port *up)
1394 {}
1395 
1396 #endif
1397 
1398 /* Enable or disable the rs485 support */
1399 static int
serial_omap_config_rs485(struct uart_port * port,struct serial_rs485 * rs485)1400 serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
1401 {
1402 	struct uart_omap_port *up = to_uart_omap_port(port);
1403 	unsigned int mode;
1404 	int val;
1405 
1406 	pm_runtime_get_sync(up->dev);
1407 
1408 	/* Disable interrupts from this port */
1409 	mode = up->ier;
1410 	up->ier = 0;
1411 	serial_out(up, UART_IER, 0);
1412 
1413 	/* Clamp the delays to [0, 100ms] */
1414 	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
1415 	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
1416 
1417 	/* store new config */
1418 	port->rs485 = *rs485;
1419 
1420 	if (up->rts_gpiod) {
1421 		/* enable / disable rts */
1422 		val = (port->rs485.flags & SER_RS485_ENABLED) ?
1423 			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
1424 		val = (port->rs485.flags & val) ? 1 : 0;
1425 		gpiod_set_value(up->rts_gpiod, val);
1426 	}
1427 
1428 	/* Enable interrupts */
1429 	up->ier = mode;
1430 	serial_out(up, UART_IER, up->ier);
1431 
1432 	/* If RS-485 is disabled, make sure the THR interrupt is fired when
1433 	 * TX FIFO is below the trigger level.
1434 	 */
1435 	if (!(port->rs485.flags & SER_RS485_ENABLED) &&
1436 	    (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
1437 		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
1438 		serial_out(up, UART_OMAP_SCR, up->scr);
1439 	}
1440 
1441 	pm_runtime_mark_last_busy(up->dev);
1442 	pm_runtime_put_autosuspend(up->dev);
1443 
1444 	return 0;
1445 }
1446 
1447 static const struct uart_ops serial_omap_pops = {
1448 	.tx_empty	= serial_omap_tx_empty,
1449 	.set_mctrl	= serial_omap_set_mctrl,
1450 	.get_mctrl	= serial_omap_get_mctrl,
1451 	.stop_tx	= serial_omap_stop_tx,
1452 	.start_tx	= serial_omap_start_tx,
1453 	.throttle	= serial_omap_throttle,
1454 	.unthrottle	= serial_omap_unthrottle,
1455 	.stop_rx	= serial_omap_stop_rx,
1456 	.enable_ms	= serial_omap_enable_ms,
1457 	.break_ctl	= serial_omap_break_ctl,
1458 	.startup	= serial_omap_startup,
1459 	.shutdown	= serial_omap_shutdown,
1460 	.set_termios	= serial_omap_set_termios,
1461 	.pm		= serial_omap_pm,
1462 	.type		= serial_omap_type,
1463 	.release_port	= serial_omap_release_port,
1464 	.request_port	= serial_omap_request_port,
1465 	.config_port	= serial_omap_config_port,
1466 	.verify_port	= serial_omap_verify_port,
1467 #ifdef CONFIG_CONSOLE_POLL
1468 	.poll_put_char  = serial_omap_poll_put_char,
1469 	.poll_get_char  = serial_omap_poll_get_char,
1470 #endif
1471 };
1472 
1473 static struct uart_driver serial_omap_reg = {
1474 	.owner		= THIS_MODULE,
1475 	.driver_name	= "OMAP-SERIAL",
1476 	.dev_name	= OMAP_SERIAL_NAME,
1477 	.nr		= OMAP_MAX_HSUART_PORTS,
1478 	.cons		= OMAP_CONSOLE,
1479 };
1480 
1481 #ifdef CONFIG_PM_SLEEP
serial_omap_prepare(struct device * dev)1482 static int serial_omap_prepare(struct device *dev)
1483 {
1484 	struct uart_omap_port *up = dev_get_drvdata(dev);
1485 
1486 	up->is_suspending = true;
1487 
1488 	return 0;
1489 }
1490 
serial_omap_complete(struct device * dev)1491 static void serial_omap_complete(struct device *dev)
1492 {
1493 	struct uart_omap_port *up = dev_get_drvdata(dev);
1494 
1495 	up->is_suspending = false;
1496 }
1497 
serial_omap_suspend(struct device * dev)1498 static int serial_omap_suspend(struct device *dev)
1499 {
1500 	struct uart_omap_port *up = dev_get_drvdata(dev);
1501 
1502 	uart_suspend_port(&serial_omap_reg, &up->port);
1503 	flush_work(&up->qos_work);
1504 
1505 	if (device_may_wakeup(dev))
1506 		serial_omap_enable_wakeup(up, true);
1507 	else
1508 		serial_omap_enable_wakeup(up, false);
1509 
1510 	return 0;
1511 }
1512 
serial_omap_resume(struct device * dev)1513 static int serial_omap_resume(struct device *dev)
1514 {
1515 	struct uart_omap_port *up = dev_get_drvdata(dev);
1516 
1517 	if (device_may_wakeup(dev))
1518 		serial_omap_enable_wakeup(up, false);
1519 
1520 	uart_resume_port(&serial_omap_reg, &up->port);
1521 
1522 	return 0;
1523 }
1524 #else
1525 #define serial_omap_prepare NULL
1526 #define serial_omap_complete NULL
1527 #endif /* CONFIG_PM_SLEEP */
1528 
omap_serial_fill_features_erratas(struct uart_omap_port * up)1529 static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
1530 {
1531 	u32 mvr, scheme;
1532 	u16 revision, major, minor;
1533 
1534 	mvr = readl(up->port.membase + (UART_OMAP_MVER << up->port.regshift));
1535 
1536 	/* Check revision register scheme */
1537 	scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
1538 
1539 	switch (scheme) {
1540 	case 0: /* Legacy Scheme: OMAP2/3 */
1541 		/* MINOR_REV[0:4], MAJOR_REV[4:7] */
1542 		major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
1543 					OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
1544 		minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
1545 		break;
1546 	case 1:
1547 		/* New Scheme: OMAP4+ */
1548 		/* MINOR_REV[0:5], MAJOR_REV[8:10] */
1549 		major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
1550 					OMAP_UART_MVR_MAJ_SHIFT;
1551 		minor = (mvr & OMAP_UART_MVR_MIN_MASK);
1552 		break;
1553 	default:
1554 		dev_warn(up->dev,
1555 			"Unknown %s revision, defaulting to highest\n",
1556 			up->name);
1557 		/* highest possible revision */
1558 		major = 0xff;
1559 		minor = 0xff;
1560 	}
1561 
1562 	/* normalize revision for the driver */
1563 	revision = UART_BUILD_REVISION(major, minor);
1564 
1565 	switch (revision) {
1566 	case OMAP_UART_REV_46:
1567 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1568 				UART_ERRATA_i291_DMA_FORCEIDLE);
1569 		break;
1570 	case OMAP_UART_REV_52:
1571 		up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1572 				UART_ERRATA_i291_DMA_FORCEIDLE);
1573 		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1574 		break;
1575 	case OMAP_UART_REV_63:
1576 		up->errata |= UART_ERRATA_i202_MDR1_ACCESS;
1577 		up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1578 		break;
1579 	default:
1580 		break;
1581 	}
1582 }
1583 
of_get_uart_port_info(struct device * dev)1584 static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
1585 {
1586 	struct omap_uart_port_info *omap_up_info;
1587 
1588 	omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
1589 	if (!omap_up_info)
1590 		return NULL; /* out of memory */
1591 
1592 	of_property_read_u32(dev->of_node, "clock-frequency",
1593 					 &omap_up_info->uartclk);
1594 
1595 	omap_up_info->flags = UPF_BOOT_AUTOCONF;
1596 
1597 	return omap_up_info;
1598 }
1599 
serial_omap_probe_rs485(struct uart_omap_port * up,struct device * dev)1600 static int serial_omap_probe_rs485(struct uart_omap_port *up,
1601 				   struct device *dev)
1602 {
1603 	struct serial_rs485 *rs485conf = &up->port.rs485;
1604 	struct device_node *np = dev->of_node;
1605 	enum gpiod_flags gflags;
1606 	int ret;
1607 
1608 	rs485conf->flags = 0;
1609 	up->rts_gpiod = NULL;
1610 
1611 	if (!np)
1612 		return 0;
1613 
1614 	ret = uart_get_rs485_mode(&up->port);
1615 	if (ret)
1616 		return ret;
1617 
1618 	if (of_property_read_bool(np, "rs485-rts-active-high")) {
1619 		rs485conf->flags |= SER_RS485_RTS_ON_SEND;
1620 		rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
1621 	} else {
1622 		rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
1623 		rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
1624 	}
1625 
1626 	/* check for tx enable gpio */
1627 	gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ?
1628 		GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
1629 	up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags);
1630 	if (IS_ERR(up->rts_gpiod)) {
1631 		ret = PTR_ERR(up->rts_gpiod);
1632 	        if (ret == -EPROBE_DEFER)
1633 			return ret;
1634 		/*
1635 		 * FIXME: the code historically ignored any other error than
1636 		 * -EPROBE_DEFER and just went on without GPIO.
1637 		 */
1638 		up->rts_gpiod = NULL;
1639 	} else {
1640 		gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
1641 	}
1642 
1643 	return 0;
1644 }
1645 
serial_omap_probe(struct platform_device * pdev)1646 static int serial_omap_probe(struct platform_device *pdev)
1647 {
1648 	struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
1649 	struct uart_omap_port *up;
1650 	struct resource *mem;
1651 	void __iomem *base;
1652 	int uartirq = 0;
1653 	int wakeirq = 0;
1654 	int ret;
1655 
1656 	/* The optional wakeirq may be specified in the board dts file */
1657 	if (pdev->dev.of_node) {
1658 		uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0);
1659 		if (!uartirq)
1660 			return -EPROBE_DEFER;
1661 		wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
1662 		omap_up_info = of_get_uart_port_info(&pdev->dev);
1663 		pdev->dev.platform_data = omap_up_info;
1664 	} else {
1665 		uartirq = platform_get_irq(pdev, 0);
1666 		if (uartirq < 0)
1667 			return -EPROBE_DEFER;
1668 	}
1669 
1670 	up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
1671 	if (!up)
1672 		return -ENOMEM;
1673 
1674 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1675 	base = devm_ioremap_resource(&pdev->dev, mem);
1676 	if (IS_ERR(base))
1677 		return PTR_ERR(base);
1678 
1679 	up->dev = &pdev->dev;
1680 	up->port.dev = &pdev->dev;
1681 	up->port.type = PORT_OMAP;
1682 	up->port.iotype = UPIO_MEM;
1683 	up->port.irq = uartirq;
1684 	up->port.regshift = 2;
1685 	up->port.fifosize = 64;
1686 	up->port.ops = &serial_omap_pops;
1687 	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_OMAP_CONSOLE);
1688 
1689 	if (pdev->dev.of_node)
1690 		ret = of_alias_get_id(pdev->dev.of_node, "serial");
1691 	else
1692 		ret = pdev->id;
1693 
1694 	if (ret < 0) {
1695 		dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
1696 			ret);
1697 		goto err_port_line;
1698 	}
1699 	up->port.line = ret;
1700 
1701 	if (up->port.line >= OMAP_MAX_HSUART_PORTS) {
1702 		dev_err(&pdev->dev, "uart ID %d >  MAX %d.\n", up->port.line,
1703 			OMAP_MAX_HSUART_PORTS);
1704 		ret = -ENXIO;
1705 		goto err_port_line;
1706 	}
1707 
1708 	up->wakeirq = wakeirq;
1709 	if (!up->wakeirq)
1710 		dev_info(up->port.dev, "no wakeirq for uart%d\n",
1711 			 up->port.line);
1712 
1713 	ret = serial_omap_probe_rs485(up, &pdev->dev);
1714 	if (ret < 0)
1715 		goto err_rs485;
1716 
1717 	sprintf(up->name, "OMAP UART%d", up->port.line);
1718 	up->port.mapbase = mem->start;
1719 	up->port.membase = base;
1720 	up->port.flags = omap_up_info->flags;
1721 	up->port.uartclk = omap_up_info->uartclk;
1722 	up->port.rs485_config = serial_omap_config_rs485;
1723 	if (!up->port.uartclk) {
1724 		up->port.uartclk = DEFAULT_CLK_SPEED;
1725 		dev_warn(&pdev->dev,
1726 			 "No clock speed specified: using default: %d\n",
1727 			 DEFAULT_CLK_SPEED);
1728 	}
1729 
1730 	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
1731 	up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
1732 	cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
1733 	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
1734 
1735 	platform_set_drvdata(pdev, up);
1736 	if (omap_up_info->autosuspend_timeout == 0)
1737 		omap_up_info->autosuspend_timeout = -1;
1738 
1739 	device_init_wakeup(up->dev, true);
1740 	pm_runtime_use_autosuspend(&pdev->dev);
1741 	pm_runtime_set_autosuspend_delay(&pdev->dev,
1742 			omap_up_info->autosuspend_timeout);
1743 
1744 	pm_runtime_irq_safe(&pdev->dev);
1745 	pm_runtime_enable(&pdev->dev);
1746 
1747 	pm_runtime_get_sync(&pdev->dev);
1748 
1749 	omap_serial_fill_features_erratas(up);
1750 
1751 	ui[up->port.line] = up;
1752 	serial_omap_add_console_port(up);
1753 
1754 	ret = uart_add_one_port(&serial_omap_reg, &up->port);
1755 	if (ret != 0)
1756 		goto err_add_port;
1757 
1758 	pm_runtime_mark_last_busy(up->dev);
1759 	pm_runtime_put_autosuspend(up->dev);
1760 	return 0;
1761 
1762 err_add_port:
1763 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1764 	pm_runtime_put_sync(&pdev->dev);
1765 	pm_runtime_disable(&pdev->dev);
1766 	cpu_latency_qos_remove_request(&up->pm_qos_request);
1767 	device_init_wakeup(up->dev, false);
1768 err_rs485:
1769 err_port_line:
1770 	return ret;
1771 }
1772 
serial_omap_remove(struct platform_device * dev)1773 static int serial_omap_remove(struct platform_device *dev)
1774 {
1775 	struct uart_omap_port *up = platform_get_drvdata(dev);
1776 
1777 	pm_runtime_get_sync(up->dev);
1778 
1779 	uart_remove_one_port(&serial_omap_reg, &up->port);
1780 
1781 	pm_runtime_dont_use_autosuspend(up->dev);
1782 	pm_runtime_put_sync(up->dev);
1783 	pm_runtime_disable(up->dev);
1784 	cpu_latency_qos_remove_request(&up->pm_qos_request);
1785 	device_init_wakeup(&dev->dev, false);
1786 
1787 	return 0;
1788 }
1789 
1790 /*
1791  * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
1792  * The access to uart register after MDR1 Access
1793  * causes UART to corrupt data.
1794  *
1795  * Need a delay =
1796  * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
1797  * give 10 times as much
1798  */
serial_omap_mdr1_errataset(struct uart_omap_port * up,u8 mdr1)1799 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
1800 {
1801 	u8 timeout = 255;
1802 
1803 	serial_out(up, UART_OMAP_MDR1, mdr1);
1804 	udelay(2);
1805 	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
1806 			UART_FCR_CLEAR_RCVR);
1807 	/*
1808 	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
1809 	 * TX_FIFO_E bit is 1.
1810 	 */
1811 	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
1812 				(UART_LSR_THRE | UART_LSR_DR))) {
1813 		timeout--;
1814 		if (!timeout) {
1815 			/* Should *never* happen. we warn and carry on */
1816 			dev_crit(up->dev, "Errata i202: timedout %x\n",
1817 						serial_in(up, UART_LSR));
1818 			break;
1819 		}
1820 		udelay(1);
1821 	}
1822 }
1823 
1824 #ifdef CONFIG_PM
serial_omap_restore_context(struct uart_omap_port * up)1825 static void serial_omap_restore_context(struct uart_omap_port *up)
1826 {
1827 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1828 		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
1829 	else
1830 		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
1831 
1832 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1833 	serial_out(up, UART_EFR, UART_EFR_ECB);
1834 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1835 	serial_out(up, UART_IER, 0x0);
1836 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1837 	serial_out(up, UART_DLL, up->dll);
1838 	serial_out(up, UART_DLM, up->dlh);
1839 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
1840 	serial_out(up, UART_IER, up->ier);
1841 	serial_out(up, UART_FCR, up->fcr);
1842 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1843 	serial_out(up, UART_MCR, up->mcr);
1844 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1845 	serial_out(up, UART_OMAP_SCR, up->scr);
1846 	serial_out(up, UART_EFR, up->efr);
1847 	serial_out(up, UART_LCR, up->lcr);
1848 	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1849 		serial_omap_mdr1_errataset(up, up->mdr1);
1850 	else
1851 		serial_out(up, UART_OMAP_MDR1, up->mdr1);
1852 	serial_out(up, UART_OMAP_WER, up->wer);
1853 }
1854 
serial_omap_runtime_suspend(struct device * dev)1855 static int serial_omap_runtime_suspend(struct device *dev)
1856 {
1857 	struct uart_omap_port *up = dev_get_drvdata(dev);
1858 
1859 	if (!up)
1860 		return -EINVAL;
1861 
1862 	/*
1863 	* When using 'no_console_suspend', the console UART must not be
1864 	* suspended. Since driver suspend is managed by runtime suspend,
1865 	* preventing runtime suspend (by returning error) will keep device
1866 	* active during suspend.
1867 	*/
1868 	if (up->is_suspending && !console_suspend_enabled &&
1869 	    uart_console(&up->port))
1870 		return -EBUSY;
1871 
1872 	up->context_loss_cnt = serial_omap_get_context_loss_count(up);
1873 
1874 	serial_omap_enable_wakeup(up, true);
1875 
1876 	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
1877 	schedule_work(&up->qos_work);
1878 
1879 	return 0;
1880 }
1881 
serial_omap_runtime_resume(struct device * dev)1882 static int serial_omap_runtime_resume(struct device *dev)
1883 {
1884 	struct uart_omap_port *up = dev_get_drvdata(dev);
1885 
1886 	int loss_cnt = serial_omap_get_context_loss_count(up);
1887 
1888 	serial_omap_enable_wakeup(up, false);
1889 
1890 	if (loss_cnt < 0) {
1891 		dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n",
1892 			loss_cnt);
1893 		serial_omap_restore_context(up);
1894 	} else if (up->context_loss_cnt != loss_cnt) {
1895 		serial_omap_restore_context(up);
1896 	}
1897 	up->latency = up->calc_latency;
1898 	schedule_work(&up->qos_work);
1899 
1900 	return 0;
1901 }
1902 #endif
1903 
1904 static const struct dev_pm_ops serial_omap_dev_pm_ops = {
1905 	SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
1906 	SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
1907 				serial_omap_runtime_resume, NULL)
1908 	.prepare        = serial_omap_prepare,
1909 	.complete       = serial_omap_complete,
1910 };
1911 
1912 #if defined(CONFIG_OF)
1913 static const struct of_device_id omap_serial_of_match[] = {
1914 	{ .compatible = "ti,omap2-uart" },
1915 	{ .compatible = "ti,omap3-uart" },
1916 	{ .compatible = "ti,omap4-uart" },
1917 	{},
1918 };
1919 MODULE_DEVICE_TABLE(of, omap_serial_of_match);
1920 #endif
1921 
1922 static struct platform_driver serial_omap_driver = {
1923 	.probe          = serial_omap_probe,
1924 	.remove         = serial_omap_remove,
1925 	.driver		= {
1926 		.name	= OMAP_SERIAL_DRIVER_NAME,
1927 		.pm	= &serial_omap_dev_pm_ops,
1928 		.of_match_table = of_match_ptr(omap_serial_of_match),
1929 	},
1930 };
1931 
serial_omap_init(void)1932 static int __init serial_omap_init(void)
1933 {
1934 	int ret;
1935 
1936 	ret = uart_register_driver(&serial_omap_reg);
1937 	if (ret != 0)
1938 		return ret;
1939 	ret = platform_driver_register(&serial_omap_driver);
1940 	if (ret != 0)
1941 		uart_unregister_driver(&serial_omap_reg);
1942 	return ret;
1943 }
1944 
serial_omap_exit(void)1945 static void __exit serial_omap_exit(void)
1946 {
1947 	platform_driver_unregister(&serial_omap_driver);
1948 	uart_unregister_driver(&serial_omap_reg);
1949 }
1950 
1951 module_init(serial_omap_init);
1952 module_exit(serial_omap_exit);
1953 
1954 MODULE_DESCRIPTION("OMAP High Speed UART driver");
1955 MODULE_LICENSE("GPL");
1956 MODULE_AUTHOR("Texas Instruments Inc");
1957