xref: /OK3568_Linux_fs/kernel/drivers/tty/serial/8250/8250_dw.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Synopsys DesignWare 8250 driver.
4  *
5  * Copyright 2011 Picochip, Jamie Iles.
6  * Copyright 2013 Intel Corporation
7  *
8  * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the
9  * LCR is written whilst busy.  If it is, then a busy detect interrupt is
10  * raised, the LCR needs to be rewritten and the uart status register read.
11  */
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/serial_8250.h>
17 #include <linux/serial_reg.h>
18 #include <linux/of.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/workqueue.h>
23 #include <linux/notifier.h>
24 #include <linux/slab.h>
25 #include <linux/acpi.h>
26 #include <linux/clk.h>
27 #include <linux/reset.h>
28 #include <linux/pm_runtime.h>
29 
30 #include <asm/byteorder.h>
31 
32 #ifdef MODULE
33 #include "8250_dwlib.c"
34 #else
35 #include "8250_dwlib.h"
36 #endif
37 
38 /* Offsets for the DesignWare specific registers */
39 #define DW_UART_USR	0x1f /* UART Status Register */
40 #define DW_UART_RFL	0x21 /* UART Receive Fifo Level Register */
41 
42 /* DesignWare specific register fields */
43 #define DW_UART_MCR_SIRE		BIT(6)
44 
45 struct dw8250_data {
46 	struct dw8250_port_data	data;
47 
48 	u8			usr_reg;
49 	int			msr_mask_on;
50 	int			msr_mask_off;
51 	struct clk		*clk;
52 	struct clk		*pclk;
53 	struct notifier_block	clk_notifier;
54 	struct work_struct	clk_work;
55 	struct reset_control	*rst;
56 
57 #ifdef CONFIG_ARCH_ROCKCHIP
58 	int			irq;
59 	int			irq_wake;
60 	int			enable_wakeup;
61 #endif
62 	unsigned int		skip_autocfg:1;
63 	unsigned int		uart_16550_compatible:1;
64 };
65 
to_dw8250_data(struct dw8250_port_data * data)66 static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
67 {
68 	return container_of(data, struct dw8250_data, data);
69 }
70 
clk_to_dw8250_data(struct notifier_block * nb)71 static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
72 {
73 	return container_of(nb, struct dw8250_data, clk_notifier);
74 }
75 
work_to_dw8250_data(struct work_struct * work)76 static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work)
77 {
78 	return container_of(work, struct dw8250_data, clk_work);
79 }
80 
dw8250_modify_msr(struct uart_port * p,int offset,int value)81 static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
82 {
83 	struct dw8250_data *d = to_dw8250_data(p->private_data);
84 
85 	/* Override any modem control signals if needed */
86 	if (offset == UART_MSR) {
87 		value |= d->msr_mask_on;
88 		value &= ~d->msr_mask_off;
89 	}
90 
91 	return value;
92 }
93 
dw8250_force_idle(struct uart_port * p)94 static void dw8250_force_idle(struct uart_port *p)
95 {
96 	struct uart_8250_port *up = up_to_u8250p(p);
97 
98 	serial8250_clear_and_reinit_fifos(up);
99 	(void)p->serial_in(p, UART_RX);
100 }
101 
dw8250_check_lcr(struct uart_port * p,int value)102 static void dw8250_check_lcr(struct uart_port *p, int value)
103 {
104 	void __iomem *offset = p->membase + (UART_LCR << p->regshift);
105 	int tries = 1000;
106 
107 	/* Make sure LCR write wasn't ignored */
108 	while (tries--) {
109 		unsigned int lcr = p->serial_in(p, UART_LCR);
110 
111 		if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
112 			return;
113 
114 		dw8250_force_idle(p);
115 
116 #ifdef CONFIG_64BIT
117 		if (p->type == PORT_OCTEON)
118 			__raw_writeq(value & 0xff, offset);
119 		else
120 #endif
121 		if (p->iotype == UPIO_MEM32)
122 			writel(value, offset);
123 		else if (p->iotype == UPIO_MEM32BE)
124 			iowrite32be(value, offset);
125 		else
126 			writeb(value, offset);
127 	}
128 	/*
129 	 * FIXME: this deadlocks if port->lock is already held
130 	 * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
131 	 */
132 }
133 
134 /* Returns once the transmitter is empty or we run out of retries */
dw8250_tx_wait_empty(struct uart_port * p)135 static void dw8250_tx_wait_empty(struct uart_port *p)
136 {
137 	struct uart_8250_port *up = up_to_u8250p(p);
138 	unsigned int tries = 20000;
139 	unsigned int delay_threshold = tries - 1000;
140 	unsigned int lsr;
141 
142 	while (tries--) {
143 		lsr = readb (p->membase + (UART_LSR << p->regshift));
144 		up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
145 
146 		if (lsr & UART_LSR_TEMT)
147 			break;
148 
149 		/* The device is first given a chance to empty without delay,
150 		 * to avoid slowdowns at high bitrates. If after 1000 tries
151 		 * the buffer has still not emptied, allow more time for low-
152 		 * speed links. */
153 		if (tries < delay_threshold)
154 			udelay (1);
155 	}
156 }
157 
dw8250_serial_out38x(struct uart_port * p,int offset,int value)158 static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
159 {
160 	struct dw8250_data *d = to_dw8250_data(p->private_data);
161 
162 	/* Allow the TX to drain before we reconfigure */
163 	if (offset == UART_LCR)
164 		dw8250_tx_wait_empty(p);
165 
166 	writeb(value, p->membase + (offset << p->regshift));
167 
168 	if (offset == UART_LCR && !d->uart_16550_compatible)
169 		dw8250_check_lcr(p, value);
170 }
171 
172 
dw8250_serial_out(struct uart_port * p,int offset,int value)173 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
174 {
175 	struct dw8250_data *d = to_dw8250_data(p->private_data);
176 
177 	writeb(value, p->membase + (offset << p->regshift));
178 
179 	if (offset == UART_LCR && !d->uart_16550_compatible)
180 		dw8250_check_lcr(p, value);
181 }
182 
dw8250_serial_in(struct uart_port * p,int offset)183 static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
184 {
185 	unsigned int value = readb(p->membase + (offset << p->regshift));
186 
187 	return dw8250_modify_msr(p, offset, value);
188 }
189 
190 #ifdef CONFIG_64BIT
dw8250_serial_inq(struct uart_port * p,int offset)191 static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)
192 {
193 	unsigned int value;
194 
195 	value = (u8)__raw_readq(p->membase + (offset << p->regshift));
196 
197 	return dw8250_modify_msr(p, offset, value);
198 }
199 
dw8250_serial_outq(struct uart_port * p,int offset,int value)200 static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
201 {
202 	struct dw8250_data *d = to_dw8250_data(p->private_data);
203 
204 	value &= 0xff;
205 	__raw_writeq(value, p->membase + (offset << p->regshift));
206 	/* Read back to ensure register write ordering. */
207 	__raw_readq(p->membase + (UART_LCR << p->regshift));
208 
209 	if (offset == UART_LCR && !d->uart_16550_compatible)
210 		dw8250_check_lcr(p, value);
211 }
212 #endif /* CONFIG_64BIT */
213 
dw8250_serial_out32(struct uart_port * p,int offset,int value)214 static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
215 {
216 	struct dw8250_data *d = to_dw8250_data(p->private_data);
217 
218 	writel(value, p->membase + (offset << p->regshift));
219 
220 	if (offset == UART_LCR && !d->uart_16550_compatible)
221 		dw8250_check_lcr(p, value);
222 }
223 
dw8250_serial_in32(struct uart_port * p,int offset)224 static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
225 {
226 	unsigned int value = readl(p->membase + (offset << p->regshift));
227 
228 	return dw8250_modify_msr(p, offset, value);
229 }
230 
dw8250_serial_out32be(struct uart_port * p,int offset,int value)231 static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
232 {
233 	struct dw8250_data *d = to_dw8250_data(p->private_data);
234 
235 	iowrite32be(value, p->membase + (offset << p->regshift));
236 
237 	if (offset == UART_LCR && !d->uart_16550_compatible)
238 		dw8250_check_lcr(p, value);
239 }
240 
dw8250_serial_in32be(struct uart_port * p,int offset)241 static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
242 {
243        unsigned int value = ioread32be(p->membase + (offset << p->regshift));
244 
245        return dw8250_modify_msr(p, offset, value);
246 }
247 
248 
dw8250_handle_irq(struct uart_port * p)249 static int dw8250_handle_irq(struct uart_port *p)
250 {
251 	struct dw8250_data *d = to_dw8250_data(p->private_data);
252 	unsigned int iir = p->serial_in(p, UART_IIR);
253 	unsigned int status, usr, rfl;
254 	unsigned long flags;
255 
256 	/*
257 	 * There are ways to get Designware-based UARTs into a state where
258 	 * they are asserting UART_IIR_RX_TIMEOUT but there is no actual
259 	 * data available.  If we see such a case then we'll do a bogus
260 	 * read.  If we don't do this then the "RX TIMEOUT" interrupt will
261 	 * fire forever.
262 	 */
263 	if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) {
264 		spin_lock_irqsave(&p->lock, flags);
265 		usr = p->serial_in(p, d->usr_reg);
266 		status = p->serial_in(p, UART_LSR);
267 		rfl = p->serial_in(p, DW_UART_RFL);
268 		if (!(status & (UART_LSR_DR | UART_LSR_BI)) && !(usr & 0x1) && (rfl == 0))
269 			(void) p->serial_in(p, UART_RX);
270 
271 		spin_unlock_irqrestore(&p->lock, flags);
272 	}
273 
274 	if (serial8250_handle_irq(p, iir))
275 		return 1;
276 
277 	if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
278 		/* Clear the USR */
279 		(void)p->serial_in(p, d->usr_reg);
280 
281 		return 1;
282 	}
283 
284 	return 0;
285 }
286 
dw8250_clk_work_cb(struct work_struct * work)287 static void dw8250_clk_work_cb(struct work_struct *work)
288 {
289 	struct dw8250_data *d = work_to_dw8250_data(work);
290 	struct uart_8250_port *up;
291 	unsigned long rate;
292 
293 	rate = clk_get_rate(d->clk);
294 	if (rate <= 0)
295 		return;
296 
297 	up = serial8250_get_port(d->data.line);
298 
299 	serial8250_update_uartclk(&up->port, rate);
300 }
301 
dw8250_clk_notifier_cb(struct notifier_block * nb,unsigned long event,void * data)302 static int dw8250_clk_notifier_cb(struct notifier_block *nb,
303 				  unsigned long event, void *data)
304 {
305 	struct dw8250_data *d = clk_to_dw8250_data(nb);
306 
307 	/*
308 	 * We have no choice but to defer the uartclk update due to two
309 	 * deadlocks. First one is caused by a recursive mutex lock which
310 	 * happens when clk_set_rate() is called from dw8250_set_termios().
311 	 * Second deadlock is more tricky and is caused by an inverted order of
312 	 * the clk and tty-port mutexes lock. It happens if clock rate change
313 	 * is requested asynchronously while set_termios() is executed between
314 	 * tty-port mutex lock and clk_set_rate() function invocation and
315 	 * vise-versa. Anyway if we didn't have the reference clock alteration
316 	 * in the dw8250_set_termios() method we wouldn't have needed this
317 	 * deferred event handling complication.
318 	 */
319 	if (event == POST_RATE_CHANGE) {
320 		queue_work(system_unbound_wq, &d->clk_work);
321 		return NOTIFY_OK;
322 	}
323 
324 	return NOTIFY_DONE;
325 }
326 
327 static void
dw8250_do_pm(struct uart_port * port,unsigned int state,unsigned int old)328 dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
329 {
330 	if (!state)
331 		pm_runtime_get_sync(port->dev);
332 
333 	serial8250_do_pm(port, state, old);
334 
335 	if (state)
336 		pm_runtime_put_sync_suspend(port->dev);
337 }
338 
dw8250_set_termios(struct uart_port * p,struct ktermios * termios,struct ktermios * old)339 static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
340 			       struct ktermios *old)
341 {
342 #ifndef CONFIG_ARCH_ROCKCHIP
343 	unsigned long newrate = tty_termios_baud_rate(termios) * 16;
344 #endif
345 	struct dw8250_data *d = to_dw8250_data(p->private_data);
346 	long rate;
347 #ifdef CONFIG_ARCH_ROCKCHIP
348 	unsigned int baud = tty_termios_baud_rate(termios);
349 	unsigned int rate_temp, diff;
350 #endif
351 	int ret;
352 
353 	clk_disable_unprepare(d->clk);
354 #ifdef CONFIG_ARCH_ROCKCHIP
355 	if (d->clk) {
356 		if (baud <= 115200)
357 			rate = 24000000;
358 		else if (baud == 230400)
359 			rate = baud * 16 * 2;
360 		else if (baud == 1152000)
361 			rate = baud * 16 * 2;
362 		else
363 			rate = baud * 16;
364 
365 		ret = clk_set_rate(d->clk, rate);
366 		rate_temp = clk_get_rate(d->clk);
367 		diff = rate * 20 / 1000;
368 		/*
369 		 * If rate_temp is not equal to rate, is means fractional frequency
370 		 * division is failed. Then use Integer frequency division, and
371 		 * the baud rate error must be under -+2%
372 		 */
373 		if ((rate_temp < rate) && ((rate - rate_temp) > diff)) {
374 			ret = clk_set_rate(d->clk, rate + diff);
375 			rate_temp = clk_get_rate(d->clk);
376 			if ((rate_temp < rate) && ((rate - rate_temp) > diff))
377 				dev_info(p->dev, "set rate:%ld, but get rate:%d\n",
378 					 rate, rate_temp);
379 			else if ((rate < rate_temp) && ((rate_temp - rate) > diff))
380 				dev_info(p->dev, "set rate:%ld, but get rate:%d\n",
381 					 rate, rate_temp);
382 		}
383 		if (!ret)
384 			p->uartclk = rate;
385 	}
386 #else
387 	rate = clk_round_rate(d->clk, newrate);
388 	if (rate > 0) {
389 		/*
390 		 * Premilinary set the uartclk to the new clock rate so the
391 		 * clock update event handler caused by the clk_set_rate()
392 		 * calling wouldn't actually update the UART divisor since
393 		 * we about to do this anyway.
394 		 */
395 		swap(p->uartclk, rate);
396 		ret = clk_set_rate(d->clk, newrate);
397 		if (ret)
398 			swap(p->uartclk, rate);
399 	}
400 #endif
401 	clk_prepare_enable(d->clk);
402 
403 	p->status &= ~UPSTAT_AUTOCTS;
404 	if (termios->c_cflag & CRTSCTS)
405 		p->status |= UPSTAT_AUTOCTS;
406 
407 	serial8250_do_set_termios(p, termios, old);
408 }
409 
dw8250_set_ldisc(struct uart_port * p,struct ktermios * termios)410 static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
411 {
412 	struct uart_8250_port *up = up_to_u8250p(p);
413 	unsigned int mcr = p->serial_in(p, UART_MCR);
414 
415 	if (up->capabilities & UART_CAP_IRDA) {
416 		if (termios->c_line == N_IRDA)
417 			mcr |= DW_UART_MCR_SIRE;
418 		else
419 			mcr &= ~DW_UART_MCR_SIRE;
420 
421 		p->serial_out(p, UART_MCR, mcr);
422 	}
423 	serial8250_do_set_ldisc(p, termios);
424 }
425 
426 /*
427  * dw8250_fallback_dma_filter will prevent the UART from getting just any free
428  * channel on platforms that have DMA engines, but don't have any channels
429  * assigned to the UART.
430  *
431  * REVISIT: This is a work around for limitation in the DMA Engine API. Once the
432  * core problem is fixed, this function is no longer needed.
433  */
dw8250_fallback_dma_filter(struct dma_chan * chan,void * param)434 static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
435 {
436 	return false;
437 }
438 
dw8250_idma_filter(struct dma_chan * chan,void * param)439 static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
440 {
441 	return param == chan->device->dev;
442 }
443 
dw8250_quirks(struct uart_port * p,struct dw8250_data * data)444 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
445 {
446 	if (p->dev->of_node) {
447 		struct device_node *np = p->dev->of_node;
448 		int id;
449 
450 		/* get index of serial line, if found in DT aliases */
451 		id = of_alias_get_id(np, "serial");
452 		if (id >= 0)
453 			p->line = id;
454 
455 		if (IS_ENABLED(CONFIG_ROCKCHIP_MINI_KERNEL))
456 			return;
457 
458 #ifdef CONFIG_64BIT
459 		if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
460 			p->serial_in = dw8250_serial_inq;
461 			p->serial_out = dw8250_serial_outq;
462 			p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
463 			p->type = PORT_OCTEON;
464 			data->usr_reg = 0x27;
465 			data->skip_autocfg = true;
466 		}
467 #endif
468 		if (of_device_is_big_endian(p->dev->of_node)) {
469 			p->iotype = UPIO_MEM32BE;
470 			p->serial_in = dw8250_serial_in32be;
471 			p->serial_out = dw8250_serial_out32be;
472 		}
473 		if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
474 			p->serial_out = dw8250_serial_out38x;
475 
476 	} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
477 		p->iotype = UPIO_MEM32;
478 		p->regshift = 2;
479 		p->serial_in = dw8250_serial_in32;
480 		data->uart_16550_compatible = true;
481 	}
482 
483 	if (IS_ENABLED(CONFIG_ROCKCHIP_MINI_KERNEL))
484 		return;
485 
486 	/* Platforms with iDMA 64-bit */
487 	if (platform_get_resource_byname(to_platform_device(p->dev),
488 					 IORESOURCE_MEM, "lpss_priv")) {
489 		data->data.dma.rx_param = p->dev->parent;
490 		data->data.dma.tx_param = p->dev->parent;
491 		data->data.dma.fn = dw8250_idma_filter;
492 	}
493 }
494 
dw8250_probe(struct platform_device * pdev)495 static int dw8250_probe(struct platform_device *pdev)
496 {
497 	struct uart_8250_port uart = {}, *up = &uart;
498 	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
499 	struct uart_port *p = &up->port;
500 	struct device *dev = &pdev->dev;
501 	struct dw8250_data *data;
502 	int irq;
503 	int err;
504 	u32 val;
505 
506 	if (!regs) {
507 		dev_err(dev, "no registers defined\n");
508 		return -EINVAL;
509 	}
510 
511 	irq = platform_get_irq(pdev, 0);
512 	if (irq < 0)
513 		return irq;
514 
515 	spin_lock_init(&p->lock);
516 	p->mapbase	= regs->start;
517 	p->irq		= irq;
518 	p->handle_irq	= dw8250_handle_irq;
519 	p->pm		= dw8250_do_pm;
520 	p->type		= PORT_8250;
521 	p->flags	= UPF_SHARE_IRQ | UPF_FIXED_PORT;
522 	p->dev		= dev;
523 	p->iotype	= UPIO_MEM;
524 	p->serial_in	= dw8250_serial_in;
525 	p->serial_out	= dw8250_serial_out;
526 	p->set_ldisc	= dw8250_set_ldisc;
527 	p->set_termios	= dw8250_set_termios;
528 
529 	p->membase = devm_ioremap(dev, regs->start, resource_size(regs));
530 	if (!p->membase)
531 		return -ENOMEM;
532 
533 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
534 	if (!data)
535 		return -ENOMEM;
536 
537 	data->data.dma.fn = dw8250_fallback_dma_filter;
538 	data->usr_reg = DW_UART_USR;
539 	p->private_data = &data->data;
540 #ifdef CONFIG_ARCH_ROCKCHIP
541 	data->irq	= irq;
542 #endif
543 
544 	data->uart_16550_compatible = device_property_read_bool(dev,
545 						"snps,uart-16550-compatible");
546 
547 	err = device_property_read_u32(dev, "reg-shift", &val);
548 	if (!err)
549 		p->regshift = val;
550 
551 	err = device_property_read_u32(dev, "reg-io-width", &val);
552 	if (!err && val == 4) {
553 		p->iotype = UPIO_MEM32;
554 		p->serial_in = dw8250_serial_in32;
555 		p->serial_out = dw8250_serial_out32;
556 	}
557 
558 	if (device_property_read_bool(dev, "dcd-override")) {
559 		/* Always report DCD as active */
560 		data->msr_mask_on |= UART_MSR_DCD;
561 		data->msr_mask_off |= UART_MSR_DDCD;
562 	}
563 
564 	if (device_property_read_bool(dev, "dsr-override")) {
565 		/* Always report DSR as active */
566 		data->msr_mask_on |= UART_MSR_DSR;
567 		data->msr_mask_off |= UART_MSR_DDSR;
568 	}
569 
570 	if (device_property_read_bool(dev, "cts-override")) {
571 		/* Always report CTS as active */
572 		data->msr_mask_on |= UART_MSR_CTS;
573 		data->msr_mask_off |= UART_MSR_DCTS;
574 	}
575 
576 	if (device_property_read_bool(dev, "ri-override")) {
577 		/* Always report Ring indicator as inactive */
578 		data->msr_mask_off |= UART_MSR_RI;
579 		data->msr_mask_off |= UART_MSR_TERI;
580 	}
581 
582 #ifdef CONFIG_ARCH_ROCKCHIP
583 	if (device_property_read_bool(p->dev, "wakeup-source"))
584 		data->enable_wakeup = 1;
585 	else
586 		data->enable_wakeup = 0;
587 #endif
588 
589 	/* Always ask for fixed clock rate from a property. */
590 	device_property_read_u32(dev, "clock-frequency", &p->uartclk);
591 
592 	/* If there is separate baudclk, get the rate from it. */
593 	data->clk = devm_clk_get_optional(dev, "baudclk");
594 	if (data->clk == NULL)
595 		data->clk = devm_clk_get_optional(dev, NULL);
596 	if (IS_ERR(data->clk))
597 		return PTR_ERR(data->clk);
598 
599 	INIT_WORK(&data->clk_work, dw8250_clk_work_cb);
600 	data->clk_notifier.notifier_call = dw8250_clk_notifier_cb;
601 
602 	err = clk_prepare_enable(data->clk);
603 	if (err)
604 		dev_warn(dev, "could not enable optional baudclk: %d\n", err);
605 
606 	if (data->clk)
607 		p->uartclk = clk_get_rate(data->clk);
608 
609 	/* If no clock rate is defined, fail. */
610 	if (!p->uartclk) {
611 		dev_err(dev, "clock rate not defined\n");
612 		err = -EINVAL;
613 		goto err_clk;
614 	}
615 
616 	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
617 	if (IS_ERR(data->pclk)) {
618 		err = PTR_ERR(data->pclk);
619 		goto err_clk;
620 	}
621 
622 	err = clk_prepare_enable(data->pclk);
623 	if (err) {
624 		dev_err(dev, "could not enable apb_pclk\n");
625 		goto err_clk;
626 	}
627 
628 	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
629 	if (IS_ERR(data->rst)) {
630 		err = PTR_ERR(data->rst);
631 		goto err_pclk;
632 	}
633 	reset_control_deassert(data->rst);
634 
635 	dw8250_quirks(p, data);
636 
637 	/* If the Busy Functionality is not implemented, don't handle it */
638 	if (data->uart_16550_compatible)
639 		p->handle_irq = NULL;
640 
641 	if (!data->skip_autocfg)
642 		dw8250_setup_port(p);
643 
644 	/* If we have a valid fifosize, try hooking up DMA */
645 	if (p->fifosize) {
646 		data->data.dma.rxconf.src_maxburst = p->fifosize / 4;
647 		data->data.dma.txconf.dst_maxburst = p->fifosize / 4;
648 		up->dma = &data->data.dma;
649 	}
650 
651 	data->data.line = serial8250_register_8250_port(up);
652 	if (data->data.line < 0) {
653 		err = data->data.line;
654 		goto err_reset;
655 	}
656 
657 	/*
658 	 * Some platforms may provide a reference clock shared between several
659 	 * devices. In this case any clock state change must be known to the
660 	 * UART port at least post factum.
661 	 */
662 	if (data->clk) {
663 		err = clk_notifier_register(data->clk, &data->clk_notifier);
664 		if (err)
665 			dev_warn(p->dev, "Failed to set the clock notifier\n");
666 		else
667 			queue_work(system_unbound_wq, &data->clk_work);
668 	}
669 #ifdef CONFIG_ARCH_ROCKCHIP
670 	if (data->enable_wakeup)
671 		device_init_wakeup(&pdev->dev, true);
672 #endif
673 	platform_set_drvdata(pdev, data);
674 
675 	pm_runtime_set_active(dev);
676 	pm_runtime_enable(dev);
677 
678 	return 0;
679 
680 err_reset:
681 	reset_control_assert(data->rst);
682 
683 err_pclk:
684 	clk_disable_unprepare(data->pclk);
685 
686 err_clk:
687 	clk_disable_unprepare(data->clk);
688 
689 	return err;
690 }
691 
dw8250_remove(struct platform_device * pdev)692 static int dw8250_remove(struct platform_device *pdev)
693 {
694 	struct dw8250_data *data = platform_get_drvdata(pdev);
695 	struct device *dev = &pdev->dev;
696 
697 	pm_runtime_get_sync(dev);
698 
699 	if (data->clk) {
700 		clk_notifier_unregister(data->clk, &data->clk_notifier);
701 
702 		flush_work(&data->clk_work);
703 	}
704 
705 	serial8250_unregister_port(data->data.line);
706 
707 	reset_control_assert(data->rst);
708 
709 	clk_disable_unprepare(data->pclk);
710 
711 	clk_disable_unprepare(data->clk);
712 
713 	pm_runtime_disable(dev);
714 	pm_runtime_put_noidle(dev);
715 #ifdef CONFIG_ARCH_ROCKCHIP
716 	if (data->enable_wakeup)
717 		device_init_wakeup(&pdev->dev, false);
718 #endif
719 
720 	return 0;
721 }
722 
723 #ifdef CONFIG_PM_SLEEP
dw8250_suspend(struct device * dev)724 static int dw8250_suspend(struct device *dev)
725 {
726 	struct dw8250_data *data = dev_get_drvdata(dev);
727 
728 #ifdef CONFIG_ARCH_ROCKCHIP
729 	if (device_may_wakeup(dev)) {
730 		if (!enable_irq_wake(data->irq))
731 			data->irq_wake = 1;
732 		return 0;
733 	}
734 #endif
735 	serial8250_suspend_port(data->data.line);
736 
737 	return 0;
738 }
739 
dw8250_resume(struct device * dev)740 static int dw8250_resume(struct device *dev)
741 {
742 	struct dw8250_data *data = dev_get_drvdata(dev);
743 
744 #ifdef CONFIG_ARCH_ROCKCHIP
745 	if (device_may_wakeup(dev)) {
746 		if (data->irq_wake) {
747 			disable_irq_wake(data->irq);
748 			data->irq_wake = 0;
749 		}
750 		return 0;
751 	}
752 #endif
753 	serial8250_resume_port(data->data.line);
754 
755 	return 0;
756 }
757 #endif /* CONFIG_PM_SLEEP */
758 
759 #ifdef CONFIG_PM
dw8250_runtime_suspend(struct device * dev)760 static int dw8250_runtime_suspend(struct device *dev)
761 {
762 	struct dw8250_data *data = dev_get_drvdata(dev);
763 
764 	clk_disable_unprepare(data->clk);
765 
766 	clk_disable_unprepare(data->pclk);
767 
768 	return 0;
769 }
770 
dw8250_runtime_resume(struct device * dev)771 static int dw8250_runtime_resume(struct device *dev)
772 {
773 	struct dw8250_data *data = dev_get_drvdata(dev);
774 
775 	clk_prepare_enable(data->pclk);
776 
777 	clk_prepare_enable(data->clk);
778 
779 	return 0;
780 }
781 #endif
782 
783 static const struct dev_pm_ops dw8250_pm_ops = {
784 	SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
785 	SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
786 };
787 
788 static const struct of_device_id dw8250_of_match[] = {
789 	{ .compatible = "snps,dw-apb-uart" },
790 #ifndef CONFIG_ROCKCHIP_MINI_KERNEL
791 	{ .compatible = "cavium,octeon-3860-uart" },
792 	{ .compatible = "marvell,armada-38x-uart" },
793 	{ .compatible = "renesas,rzn1-uart" },
794 #endif
795 	{ /* Sentinel */ }
796 };
797 MODULE_DEVICE_TABLE(of, dw8250_of_match);
798 
799 static const struct acpi_device_id dw8250_acpi_match[] = {
800 	{ "INT33C4", 0 },
801 	{ "INT33C5", 0 },
802 	{ "INT3434", 0 },
803 	{ "INT3435", 0 },
804 	{ "80860F0A", 0 },
805 	{ "8086228A", 0 },
806 	{ "APMC0D08", 0},
807 	{ "AMD0020", 0 },
808 	{ "AMDI0020", 0 },
809 	{ "AMDI0022", 0 },
810 	{ "BRCM2032", 0 },
811 	{ "HISI0031", 0 },
812 	{ },
813 };
814 MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
815 
816 static struct platform_driver dw8250_platform_driver = {
817 	.driver = {
818 		.name		= "dw-apb-uart",
819 		.pm		= &dw8250_pm_ops,
820 		.of_match_table	= dw8250_of_match,
821 		.acpi_match_table = dw8250_acpi_match,
822 	},
823 	.probe			= dw8250_probe,
824 	.remove			= dw8250_remove,
825 };
826 
827 module_platform_driver(dw8250_platform_driver);
828 
829 MODULE_AUTHOR("Jamie Iles");
830 MODULE_LICENSE("GPL");
831 MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver");
832 MODULE_ALIAS("platform:dw-apb-uart");
833