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