xref: /linux/drivers/tty/serial/8250/8250_dw.c (revision 001821b0e79716c4e17c71d8e053a23599a7a508)
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/clk.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/io.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/module.h>
18 #include <linux/notifier.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/property.h>
22 #include <linux/reset.h>
23 #include <linux/slab.h>
24 #include <linux/workqueue.h>
25 
26 #include <asm/byteorder.h>
27 
28 #include <linux/serial_8250.h>
29 #include <linux/serial_reg.h>
30 
31 #include "8250_dwlib.h"
32 
33 /* Offsets for the DesignWare specific registers */
34 #define DW_UART_USR	0x1f /* UART Status Register */
35 #define DW_UART_DMASA	0xa8 /* DMA Software Ack */
36 
37 #define OCTEON_UART_USR	0x27 /* UART Status Register */
38 
39 #define RZN1_UART_TDMACR 0x10c /* DMA Control Register Transmit Mode */
40 #define RZN1_UART_RDMACR 0x110 /* DMA Control Register Receive Mode */
41 
42 /* DesignWare specific register fields */
43 #define DW_UART_MCR_SIRE		BIT(6)
44 
45 /* Renesas specific register fields */
46 #define RZN1_UART_xDMACR_DMA_EN		BIT(0)
47 #define RZN1_UART_xDMACR_1_WORD_BURST	(0 << 1)
48 #define RZN1_UART_xDMACR_4_WORD_BURST	(1 << 1)
49 #define RZN1_UART_xDMACR_8_WORD_BURST	(2 << 1)
50 #define RZN1_UART_xDMACR_BLK_SZ(x)	((x) << 3)
51 
52 /* Quirks */
53 #define DW_UART_QUIRK_OCTEON		BIT(0)
54 #define DW_UART_QUIRK_ARMADA_38X	BIT(1)
55 #define DW_UART_QUIRK_SKIP_SET_RATE	BIT(2)
56 #define DW_UART_QUIRK_IS_DMA_FC		BIT(3)
57 #define DW_UART_QUIRK_APMC0D08		BIT(4)
58 
59 static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
60 {
61 	return container_of(nb, struct dw8250_data, clk_notifier);
62 }
63 
64 static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work)
65 {
66 	return container_of(work, struct dw8250_data, clk_work);
67 }
68 
69 static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
70 {
71 	struct dw8250_data *d = to_dw8250_data(p->private_data);
72 
73 	/* Override any modem control signals if needed */
74 	if (offset == UART_MSR) {
75 		value |= d->msr_mask_on;
76 		value &= ~d->msr_mask_off;
77 	}
78 
79 	return value;
80 }
81 
82 static void dw8250_force_idle(struct uart_port *p)
83 {
84 	struct uart_8250_port *up = up_to_u8250p(p);
85 	unsigned int lsr;
86 
87 	serial8250_clear_and_reinit_fifos(up);
88 
89 	/*
90 	 * With PSLVERR_RESP_EN parameter set to 1, the device generates an
91 	 * error response when an attempt to read an empty RBR with FIFO
92 	 * enabled.
93 	 */
94 	if (up->fcr & UART_FCR_ENABLE_FIFO) {
95 		lsr = p->serial_in(p, UART_LSR);
96 		if (!(lsr & UART_LSR_DR))
97 			return;
98 	}
99 
100 	(void)p->serial_in(p, UART_RX);
101 }
102 
103 static void dw8250_check_lcr(struct uart_port *p, int offset, int value)
104 {
105 	struct dw8250_data *d = to_dw8250_data(p->private_data);
106 	void __iomem *addr = p->membase + (offset << p->regshift);
107 	int tries = 1000;
108 
109 	if (offset != UART_LCR || d->uart_16550_compatible)
110 		return;
111 
112 	/* Make sure LCR write wasn't ignored */
113 	while (tries--) {
114 		unsigned int lcr = p->serial_in(p, offset);
115 
116 		if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
117 			return;
118 
119 		dw8250_force_idle(p);
120 
121 #ifdef CONFIG_64BIT
122 		if (p->type == PORT_OCTEON)
123 			__raw_writeq(value & 0xff, addr);
124 		else
125 #endif
126 		if (p->iotype == UPIO_MEM32)
127 			writel(value, addr);
128 		else if (p->iotype == UPIO_MEM32BE)
129 			iowrite32be(value, addr);
130 		else
131 			writeb(value, addr);
132 	}
133 	/*
134 	 * FIXME: this deadlocks if port->lock is already held
135 	 * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
136 	 */
137 }
138 
139 /* Returns once the transmitter is empty or we run out of retries */
140 static void dw8250_tx_wait_empty(struct uart_port *p)
141 {
142 	struct uart_8250_port *up = up_to_u8250p(p);
143 	unsigned int tries = 20000;
144 	unsigned int delay_threshold = tries - 1000;
145 	unsigned int lsr;
146 
147 	while (tries--) {
148 		lsr = readb (p->membase + (UART_LSR << p->regshift));
149 		up->lsr_saved_flags |= lsr & up->lsr_save_mask;
150 
151 		if (lsr & UART_LSR_TEMT)
152 			break;
153 
154 		/* The device is first given a chance to empty without delay,
155 		 * to avoid slowdowns at high bitrates. If after 1000 tries
156 		 * the buffer has still not emptied, allow more time for low-
157 		 * speed links. */
158 		if (tries < delay_threshold)
159 			udelay (1);
160 	}
161 }
162 
163 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
164 {
165 	writeb(value, p->membase + (offset << p->regshift));
166 	dw8250_check_lcr(p, offset, value);
167 }
168 
169 static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
170 {
171 	/* Allow the TX to drain before we reconfigure */
172 	if (offset == UART_LCR)
173 		dw8250_tx_wait_empty(p);
174 
175 	dw8250_serial_out(p, offset, value);
176 }
177 
178 static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
179 {
180 	unsigned int value = readb(p->membase + (offset << p->regshift));
181 
182 	return dw8250_modify_msr(p, offset, value);
183 }
184 
185 #ifdef CONFIG_64BIT
186 static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)
187 {
188 	u8 value = __raw_readq(p->membase + (offset << p->regshift));
189 
190 	return dw8250_modify_msr(p, offset, value);
191 }
192 
193 static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
194 {
195 	value &= 0xff;
196 	__raw_writeq(value, p->membase + (offset << p->regshift));
197 	/* Read back to ensure register write ordering. */
198 	__raw_readq(p->membase + (UART_LCR << p->regshift));
199 
200 	dw8250_check_lcr(p, offset, value);
201 }
202 #endif /* CONFIG_64BIT */
203 
204 static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
205 {
206 	writel(value, p->membase + (offset << p->regshift));
207 	dw8250_check_lcr(p, offset, value);
208 }
209 
210 static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
211 {
212 	unsigned int value = readl(p->membase + (offset << p->regshift));
213 
214 	return dw8250_modify_msr(p, offset, value);
215 }
216 
217 static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
218 {
219 	iowrite32be(value, p->membase + (offset << p->regshift));
220 	dw8250_check_lcr(p, offset, value);
221 }
222 
223 static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
224 {
225        unsigned int value = ioread32be(p->membase + (offset << p->regshift));
226 
227        return dw8250_modify_msr(p, offset, value);
228 }
229 
230 
231 static int dw8250_handle_irq(struct uart_port *p)
232 {
233 	struct uart_8250_port *up = up_to_u8250p(p);
234 	struct dw8250_data *d = to_dw8250_data(p->private_data);
235 	unsigned int iir = p->serial_in(p, UART_IIR);
236 	bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT;
237 	unsigned int quirks = d->pdata->quirks;
238 	unsigned int status;
239 	unsigned long flags;
240 
241 	/*
242 	 * There are ways to get Designware-based UARTs into a state where
243 	 * they are asserting UART_IIR_RX_TIMEOUT but there is no actual
244 	 * data available.  If we see such a case then we'll do a bogus
245 	 * read.  If we don't do this then the "RX TIMEOUT" interrupt will
246 	 * fire forever.
247 	 *
248 	 * This problem has only been observed so far when not in DMA mode
249 	 * so we limit the workaround only to non-DMA mode.
250 	 */
251 	if (!up->dma && rx_timeout) {
252 		uart_port_lock_irqsave(p, &flags);
253 		status = serial_lsr_in(up);
254 
255 		if (!(status & (UART_LSR_DR | UART_LSR_BI)))
256 			(void) p->serial_in(p, UART_RX);
257 
258 		uart_port_unlock_irqrestore(p, flags);
259 	}
260 
261 	/* Manually stop the Rx DMA transfer when acting as flow controller */
262 	if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
263 		uart_port_lock_irqsave(p, &flags);
264 		status = serial_lsr_in(up);
265 		uart_port_unlock_irqrestore(p, flags);
266 
267 		if (status & (UART_LSR_DR | UART_LSR_BI)) {
268 			dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
269 			dw8250_writel_ext(p, DW_UART_DMASA, 1);
270 		}
271 	}
272 
273 	if (serial8250_handle_irq(p, iir))
274 		return 1;
275 
276 	if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
277 		/* Clear the USR */
278 		(void)p->serial_in(p, d->pdata->usr_reg);
279 
280 		return 1;
281 	}
282 
283 	return 0;
284 }
285 
286 static void dw8250_clk_work_cb(struct work_struct *work)
287 {
288 	struct dw8250_data *d = work_to_dw8250_data(work);
289 	struct uart_8250_port *up;
290 	unsigned long rate;
291 
292 	rate = clk_get_rate(d->clk);
293 	if (rate <= 0)
294 		return;
295 
296 	up = serial8250_get_port(d->data.line);
297 
298 	serial8250_update_uartclk(&up->port, rate);
299 }
300 
301 static int dw8250_clk_notifier_cb(struct notifier_block *nb,
302 				  unsigned long event, void *data)
303 {
304 	struct dw8250_data *d = clk_to_dw8250_data(nb);
305 
306 	/*
307 	 * We have no choice but to defer the uartclk update due to two
308 	 * deadlocks. First one is caused by a recursive mutex lock which
309 	 * happens when clk_set_rate() is called from dw8250_set_termios().
310 	 * Second deadlock is more tricky and is caused by an inverted order of
311 	 * the clk and tty-port mutexes lock. It happens if clock rate change
312 	 * is requested asynchronously while set_termios() is executed between
313 	 * tty-port mutex lock and clk_set_rate() function invocation and
314 	 * vise-versa. Anyway if we didn't have the reference clock alteration
315 	 * in the dw8250_set_termios() method we wouldn't have needed this
316 	 * deferred event handling complication.
317 	 */
318 	if (event == POST_RATE_CHANGE) {
319 		queue_work(system_unbound_wq, &d->clk_work);
320 		return NOTIFY_OK;
321 	}
322 
323 	return NOTIFY_DONE;
324 }
325 
326 static void
327 dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
328 {
329 	if (!state)
330 		pm_runtime_get_sync(port->dev);
331 
332 	serial8250_do_pm(port, state, old);
333 
334 	if (state)
335 		pm_runtime_put_sync_suspend(port->dev);
336 }
337 
338 static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
339 			       const struct ktermios *old)
340 {
341 	unsigned long newrate = tty_termios_baud_rate(termios) * 16;
342 	struct dw8250_data *d = to_dw8250_data(p->private_data);
343 	long rate;
344 	int ret;
345 
346 	clk_disable_unprepare(d->clk);
347 	rate = clk_round_rate(d->clk, newrate);
348 	if (rate > 0) {
349 		/*
350 		 * Note that any clock-notifer worker will block in
351 		 * serial8250_update_uartclk() until we are done.
352 		 */
353 		ret = clk_set_rate(d->clk, newrate);
354 		if (!ret)
355 			p->uartclk = rate;
356 	}
357 	clk_prepare_enable(d->clk);
358 
359 	dw8250_do_set_termios(p, termios, old);
360 }
361 
362 static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
363 {
364 	struct uart_8250_port *up = up_to_u8250p(p);
365 	unsigned int mcr = p->serial_in(p, UART_MCR);
366 
367 	if (up->capabilities & UART_CAP_IRDA) {
368 		if (termios->c_line == N_IRDA)
369 			mcr |= DW_UART_MCR_SIRE;
370 		else
371 			mcr &= ~DW_UART_MCR_SIRE;
372 
373 		p->serial_out(p, UART_MCR, mcr);
374 	}
375 	serial8250_do_set_ldisc(p, termios);
376 }
377 
378 /*
379  * dw8250_fallback_dma_filter will prevent the UART from getting just any free
380  * channel on platforms that have DMA engines, but don't have any channels
381  * assigned to the UART.
382  *
383  * REVISIT: This is a work around for limitation in the DMA Engine API. Once the
384  * core problem is fixed, this function is no longer needed.
385  */
386 static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
387 {
388 	return false;
389 }
390 
391 static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
392 {
393 	return param == chan->device->dev;
394 }
395 
396 static u32 dw8250_rzn1_get_dmacr_burst(int max_burst)
397 {
398 	if (max_burst >= 8)
399 		return RZN1_UART_xDMACR_8_WORD_BURST;
400 	else if (max_burst >= 4)
401 		return RZN1_UART_xDMACR_4_WORD_BURST;
402 	else
403 		return RZN1_UART_xDMACR_1_WORD_BURST;
404 }
405 
406 static void dw8250_prepare_tx_dma(struct uart_8250_port *p)
407 {
408 	struct uart_port *up = &p->port;
409 	struct uart_8250_dma *dma = p->dma;
410 	u32 val;
411 
412 	dw8250_writel_ext(up, RZN1_UART_TDMACR, 0);
413 	val = dw8250_rzn1_get_dmacr_burst(dma->txconf.dst_maxburst) |
414 	      RZN1_UART_xDMACR_BLK_SZ(dma->tx_size) |
415 	      RZN1_UART_xDMACR_DMA_EN;
416 	dw8250_writel_ext(up, RZN1_UART_TDMACR, val);
417 }
418 
419 static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
420 {
421 	struct uart_port *up = &p->port;
422 	struct uart_8250_dma *dma = p->dma;
423 	u32 val;
424 
425 	dw8250_writel_ext(up, RZN1_UART_RDMACR, 0);
426 	val = dw8250_rzn1_get_dmacr_burst(dma->rxconf.src_maxburst) |
427 	      RZN1_UART_xDMACR_BLK_SZ(dma->rx_size) |
428 	      RZN1_UART_xDMACR_DMA_EN;
429 	dw8250_writel_ext(up, RZN1_UART_RDMACR, val);
430 }
431 
432 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
433 {
434 	unsigned int quirks = data->pdata ? data->pdata->quirks : 0;
435 
436 #ifdef CONFIG_64BIT
437 	if (quirks & DW_UART_QUIRK_OCTEON) {
438 		p->serial_in = dw8250_serial_inq;
439 		p->serial_out = dw8250_serial_outq;
440 		p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
441 		p->type = PORT_OCTEON;
442 		data->skip_autocfg = true;
443 	}
444 #endif
445 
446 	if (quirks & DW_UART_QUIRK_ARMADA_38X)
447 		p->serial_out = dw8250_serial_out38x;
448 	if (quirks & DW_UART_QUIRK_SKIP_SET_RATE)
449 		p->set_termios = dw8250_do_set_termios;
450 	if (quirks & DW_UART_QUIRK_IS_DMA_FC) {
451 		data->data.dma.txconf.device_fc = 1;
452 		data->data.dma.rxconf.device_fc = 1;
453 		data->data.dma.prepare_tx_dma = dw8250_prepare_tx_dma;
454 		data->data.dma.prepare_rx_dma = dw8250_prepare_rx_dma;
455 	}
456 	if (quirks & DW_UART_QUIRK_APMC0D08) {
457 		p->iotype = UPIO_MEM32;
458 		p->regshift = 2;
459 		p->serial_in = dw8250_serial_in32;
460 		data->uart_16550_compatible = true;
461 	}
462 
463 	/* Platforms with iDMA 64-bit */
464 	if (platform_get_resource_byname(to_platform_device(p->dev),
465 					 IORESOURCE_MEM, "lpss_priv")) {
466 		data->data.dma.rx_param = p->dev->parent;
467 		data->data.dma.tx_param = p->dev->parent;
468 		data->data.dma.fn = dw8250_idma_filter;
469 	}
470 }
471 
472 static void dw8250_reset_control_assert(void *data)
473 {
474 	reset_control_assert(data);
475 }
476 
477 static int dw8250_probe(struct platform_device *pdev)
478 {
479 	struct uart_8250_port uart = {}, *up = &uart;
480 	struct uart_port *p = &up->port;
481 	struct device *dev = &pdev->dev;
482 	struct dw8250_data *data;
483 	struct resource *regs;
484 	int err;
485 
486 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
487 	if (!regs)
488 		return dev_err_probe(dev, -EINVAL, "no registers defined\n");
489 
490 	spin_lock_init(&p->lock);
491 	p->handle_irq	= dw8250_handle_irq;
492 	p->pm		= dw8250_do_pm;
493 	p->type		= PORT_8250;
494 	p->flags	= UPF_FIXED_PORT;
495 	p->dev		= dev;
496 	p->set_ldisc	= dw8250_set_ldisc;
497 	p->set_termios	= dw8250_set_termios;
498 
499 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
500 	if (!data)
501 		return -ENOMEM;
502 
503 	data->data.dma.fn = dw8250_fallback_dma_filter;
504 	data->pdata = device_get_match_data(p->dev);
505 	p->private_data = &data->data;
506 
507 	data->uart_16550_compatible = device_property_read_bool(dev,
508 						"snps,uart-16550-compatible");
509 
510 	p->mapbase = regs->start;
511 	p->mapsize = resource_size(regs);
512 
513 	p->membase = devm_ioremap(dev, p->mapbase, p->mapsize);
514 	if (!p->membase)
515 		return -ENOMEM;
516 
517 	err = uart_read_port_properties(p);
518 	/* no interrupt -> fall back to polling */
519 	if (err == -ENXIO)
520 		err = 0;
521 	if (err)
522 		return err;
523 
524 	switch (p->iotype) {
525 	case UPIO_MEM:
526 		p->serial_in = dw8250_serial_in;
527 		p->serial_out = dw8250_serial_out;
528 		break;
529 	case UPIO_MEM32:
530 		p->serial_in = dw8250_serial_in32;
531 		p->serial_out = dw8250_serial_out32;
532 		break;
533 	case UPIO_MEM32BE:
534 		p->serial_in = dw8250_serial_in32be;
535 		p->serial_out = dw8250_serial_out32be;
536 		break;
537 	default:
538 		return -ENODEV;
539 	}
540 
541 	if (device_property_read_bool(dev, "dcd-override")) {
542 		/* Always report DCD as active */
543 		data->msr_mask_on |= UART_MSR_DCD;
544 		data->msr_mask_off |= UART_MSR_DDCD;
545 	}
546 
547 	if (device_property_read_bool(dev, "dsr-override")) {
548 		/* Always report DSR as active */
549 		data->msr_mask_on |= UART_MSR_DSR;
550 		data->msr_mask_off |= UART_MSR_DDSR;
551 	}
552 
553 	if (device_property_read_bool(dev, "cts-override")) {
554 		/* Always report CTS as active */
555 		data->msr_mask_on |= UART_MSR_CTS;
556 		data->msr_mask_off |= UART_MSR_DCTS;
557 	}
558 
559 	if (device_property_read_bool(dev, "ri-override")) {
560 		/* Always report Ring indicator as inactive */
561 		data->msr_mask_off |= UART_MSR_RI;
562 		data->msr_mask_off |= UART_MSR_TERI;
563 	}
564 
565 	/* If there is separate baudclk, get the rate from it. */
566 	data->clk = devm_clk_get_optional_enabled(dev, "baudclk");
567 	if (data->clk == NULL)
568 		data->clk = devm_clk_get_optional_enabled(dev, NULL);
569 	if (IS_ERR(data->clk))
570 		return dev_err_probe(dev, PTR_ERR(data->clk),
571 				     "failed to get baudclk\n");
572 
573 	INIT_WORK(&data->clk_work, dw8250_clk_work_cb);
574 	data->clk_notifier.notifier_call = dw8250_clk_notifier_cb;
575 
576 	if (data->clk)
577 		p->uartclk = clk_get_rate(data->clk);
578 
579 	/* If no clock rate is defined, fail. */
580 	if (!p->uartclk)
581 		return dev_err_probe(dev, -EINVAL, "clock rate not defined\n");
582 
583 	data->pclk = devm_clk_get_optional_enabled(dev, "apb_pclk");
584 	if (IS_ERR(data->pclk))
585 		return PTR_ERR(data->pclk);
586 
587 	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
588 	if (IS_ERR(data->rst))
589 		return PTR_ERR(data->rst);
590 
591 	reset_control_deassert(data->rst);
592 
593 	err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
594 	if (err)
595 		return err;
596 
597 	dw8250_quirks(p, data);
598 
599 	/* If the Busy Functionality is not implemented, don't handle it */
600 	if (data->uart_16550_compatible)
601 		p->handle_irq = NULL;
602 
603 	if (!data->skip_autocfg)
604 		dw8250_setup_port(p);
605 
606 	/* If we have a valid fifosize, try hooking up DMA */
607 	if (p->fifosize) {
608 		data->data.dma.rxconf.src_maxburst = p->fifosize / 4;
609 		data->data.dma.txconf.dst_maxburst = p->fifosize / 4;
610 		up->dma = &data->data.dma;
611 	}
612 
613 	data->data.line = serial8250_register_8250_port(up);
614 	if (data->data.line < 0)
615 		return data->data.line;
616 
617 	/*
618 	 * Some platforms may provide a reference clock shared between several
619 	 * devices. In this case any clock state change must be known to the
620 	 * UART port at least post factum.
621 	 */
622 	if (data->clk) {
623 		err = clk_notifier_register(data->clk, &data->clk_notifier);
624 		if (err)
625 			return dev_err_probe(dev, err, "Failed to set the clock notifier\n");
626 		queue_work(system_unbound_wq, &data->clk_work);
627 	}
628 
629 	platform_set_drvdata(pdev, data);
630 
631 	pm_runtime_set_active(dev);
632 	pm_runtime_enable(dev);
633 
634 	return 0;
635 }
636 
637 static void dw8250_remove(struct platform_device *pdev)
638 {
639 	struct dw8250_data *data = platform_get_drvdata(pdev);
640 	struct device *dev = &pdev->dev;
641 
642 	pm_runtime_get_sync(dev);
643 
644 	if (data->clk) {
645 		clk_notifier_unregister(data->clk, &data->clk_notifier);
646 
647 		flush_work(&data->clk_work);
648 	}
649 
650 	serial8250_unregister_port(data->data.line);
651 
652 	pm_runtime_disable(dev);
653 	pm_runtime_put_noidle(dev);
654 }
655 
656 static int dw8250_suspend(struct device *dev)
657 {
658 	struct dw8250_data *data = dev_get_drvdata(dev);
659 
660 	serial8250_suspend_port(data->data.line);
661 
662 	return 0;
663 }
664 
665 static int dw8250_resume(struct device *dev)
666 {
667 	struct dw8250_data *data = dev_get_drvdata(dev);
668 
669 	serial8250_resume_port(data->data.line);
670 
671 	return 0;
672 }
673 
674 static int dw8250_runtime_suspend(struct device *dev)
675 {
676 	struct dw8250_data *data = dev_get_drvdata(dev);
677 
678 	clk_disable_unprepare(data->clk);
679 
680 	clk_disable_unprepare(data->pclk);
681 
682 	return 0;
683 }
684 
685 static int dw8250_runtime_resume(struct device *dev)
686 {
687 	struct dw8250_data *data = dev_get_drvdata(dev);
688 
689 	clk_prepare_enable(data->pclk);
690 
691 	clk_prepare_enable(data->clk);
692 
693 	return 0;
694 }
695 
696 static const struct dev_pm_ops dw8250_pm_ops = {
697 	SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
698 	RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
699 };
700 
701 static const struct dw8250_platform_data dw8250_dw_apb = {
702 	.usr_reg = DW_UART_USR,
703 };
704 
705 static const struct dw8250_platform_data dw8250_octeon_3860_data = {
706 	.usr_reg = OCTEON_UART_USR,
707 	.quirks = DW_UART_QUIRK_OCTEON,
708 };
709 
710 static const struct dw8250_platform_data dw8250_armada_38x_data = {
711 	.usr_reg = DW_UART_USR,
712 	.quirks = DW_UART_QUIRK_ARMADA_38X,
713 };
714 
715 static const struct dw8250_platform_data dw8250_renesas_rzn1_data = {
716 	.usr_reg = DW_UART_USR,
717 	.cpr_val = 0x00012f32,
718 	.quirks = DW_UART_QUIRK_IS_DMA_FC,
719 };
720 
721 static const struct dw8250_platform_data dw8250_starfive_jh7100_data = {
722 	.usr_reg = DW_UART_USR,
723 	.quirks = DW_UART_QUIRK_SKIP_SET_RATE,
724 };
725 
726 static const struct of_device_id dw8250_of_match[] = {
727 	{ .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb },
728 	{ .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data },
729 	{ .compatible = "marvell,armada-38x-uart", .data = &dw8250_armada_38x_data },
730 	{ .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data },
731 	{ .compatible = "starfive,jh7100-uart", .data = &dw8250_starfive_jh7100_data },
732 	{ /* Sentinel */ }
733 };
734 MODULE_DEVICE_TABLE(of, dw8250_of_match);
735 
736 static const struct dw8250_platform_data dw8250_apmc0d08 = {
737 	.usr_reg = DW_UART_USR,
738 	.quirks = DW_UART_QUIRK_APMC0D08,
739 };
740 
741 static const struct acpi_device_id dw8250_acpi_match[] = {
742 	{ "80860F0A", (kernel_ulong_t)&dw8250_dw_apb },
743 	{ "8086228A", (kernel_ulong_t)&dw8250_dw_apb },
744 	{ "AMD0020", (kernel_ulong_t)&dw8250_dw_apb },
745 	{ "AMDI0020", (kernel_ulong_t)&dw8250_dw_apb },
746 	{ "AMDI0022", (kernel_ulong_t)&dw8250_dw_apb },
747 	{ "APMC0D08", (kernel_ulong_t)&dw8250_apmc0d08 },
748 	{ "BRCM2032", (kernel_ulong_t)&dw8250_dw_apb },
749 	{ "HISI0031", (kernel_ulong_t)&dw8250_dw_apb },
750 	{ "INT33C4", (kernel_ulong_t)&dw8250_dw_apb },
751 	{ "INT33C5", (kernel_ulong_t)&dw8250_dw_apb },
752 	{ "INT3434", (kernel_ulong_t)&dw8250_dw_apb },
753 	{ "INT3435", (kernel_ulong_t)&dw8250_dw_apb },
754 	{ "INTC10EE", (kernel_ulong_t)&dw8250_dw_apb },
755 	{ },
756 };
757 MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
758 
759 static struct platform_driver dw8250_platform_driver = {
760 	.driver = {
761 		.name		= "dw-apb-uart",
762 		.pm		= pm_ptr(&dw8250_pm_ops),
763 		.of_match_table	= dw8250_of_match,
764 		.acpi_match_table = dw8250_acpi_match,
765 	},
766 	.probe			= dw8250_probe,
767 	.remove_new		= dw8250_remove,
768 };
769 
770 module_platform_driver(dw8250_platform_driver);
771 
772 MODULE_AUTHOR("Jamie Iles");
773 MODULE_LICENSE("GPL");
774 MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver");
775 MODULE_ALIAS("platform:dw-apb-uart");
776