forked from ~ljy/RK356X_SDK_RELEASE
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2024-01-04 1543e317f1da31b75942316931e8f491a8920811 
 kernel/drivers/tty/serial/8250/8250_dw.c
....@@ -19,6 +19,8 @@
1919 #include <linux/of_irq.h>
2020 #include <linux/of_platform.h>
2121 #include <linux/platform_device.h>
22
+#include <linux/workqueue.h>
23
+#include <linux/notifier.h>
2224 #include <linux/slab.h>
2325 #include <linux/acpi.h>
2426 #include <linux/clk.h>
....@@ -27,44 +29,31 @@
2729 
2830 #include <asm/byteorder.h>
2931 
30
-#include "8250.h"
32
+#ifdef MODULE
33
+#include "8250_dwlib.c"
34
+#else
35
+#include "8250_dwlib.h"
36
+#endif
3137 
3238 /* Offsets for the DesignWare specific registers */
3339 #define DW_UART_USR	0x1f /* UART Status Register */
34
-#define DW_UART_DLF	0xc0 /* Divisor Latch Fraction Register */
3540 #define DW_UART_RFL	0x21 /* UART Receive Fifo Level Register */
36
-#define DW_UART_CPR	0xf4 /* Component Parameter Register */
37
-#define DW_UART_UCV	0xf8 /* UART Component Version */
38
-
39
-/* Component Parameter Register bits */
40
-#define DW_UART_CPR_ABP_DATA_WIDTH	(3 << 0)
41
-#define DW_UART_CPR_AFCE_MODE		(1 << 4)
42
-#define DW_UART_CPR_THRE_MODE		(1 << 5)
43
-#define DW_UART_CPR_SIR_MODE		(1 << 6)
44
-#define DW_UART_CPR_SIR_LP_MODE		(1 << 7)
45
-#define DW_UART_CPR_ADDITIONAL_FEATURES	(1 << 8)
46
-#define DW_UART_CPR_FIFO_ACCESS		(1 << 9)
47
-#define DW_UART_CPR_FIFO_STAT		(1 << 10)
48
-#define DW_UART_CPR_SHADOW		(1 << 11)
49
-#define DW_UART_CPR_ENCODED_PARMS	(1 << 12)
50
-#define DW_UART_CPR_DMA_EXTRA		(1 << 13)
51
-#define DW_UART_CPR_FIFO_MODE		(0xff << 16)
52
-/* Helper for fifo size calculation */
53
-#define DW_UART_CPR_FIFO_SIZE(a)	(((a >> 16) & 0xff) * 16)
5441 
5542 /* DesignWare specific register fields */
5643 #define DW_UART_MCR_SIRE		BIT(6)
5744 
5845 struct dw8250_data {
46
+	struct dw8250_port_data	data;
47
+
5948 	u8			usr_reg;
60
-	u8			dlf_size;
61
-	int			line;
6249 	int			msr_mask_on;
6350 	int			msr_mask_off;
6451 	struct clk		*clk;
6552 	struct clk		*pclk;
53
+	struct notifier_block	clk_notifier;
54
+	struct work_struct	clk_work;
6655 	struct reset_control	*rst;
67
-	struct uart_8250_dma	dma;
56
+
6857 #ifdef CONFIG_ARCH_ROCKCHIP
6958 	int			irq;
7059 	int			irq_wake;
....@@ -74,24 +63,24 @@
7463 	unsigned int		uart_16550_compatible:1;
7564 };
7665 
77
-static inline u32 dw8250_readl_ext(struct uart_port *p, int offset)
66
+static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
7867 {
79
-	if (p->iotype == UPIO_MEM32BE)
80
-		return ioread32be(p->membase + offset);
81
-	return readl(p->membase + offset);
68
+	return container_of(data, struct dw8250_data, data);
8269 }
8370 
84
-static inline void dw8250_writel_ext(struct uart_port *p, int offset, u32 reg)
71
+static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
8572 {
86
-	if (p->iotype == UPIO_MEM32BE)
87
-		iowrite32be(reg, p->membase + offset);
88
-	else
89
-		writel(reg, p->membase + offset);
73
+	return container_of(nb, struct dw8250_data, clk_notifier);
74
+}
75
+
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);
9079 }
9180 
9281 static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
9382 {
94
-	struct dw8250_data *d = p->private_data;
83
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
9584 
9685 	/* Override any modem control signals if needed */
9786 	if (offset == UART_MSR) {
....@@ -145,12 +134,15 @@
145134 /* Returns once the transmitter is empty or we run out of retries */
146135 static void dw8250_tx_wait_empty(struct uart_port *p)
147136 {
137
+	struct uart_8250_port *up = up_to_u8250p(p);
148138 	unsigned int tries = 20000;
149139 	unsigned int delay_threshold = tries - 1000;
150140 	unsigned int lsr;
151141 
152142 	while (tries--) {
153143 		lsr = readb (p->membase + (UART_LSR << p->regshift));
144
+		up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
145
+
154146 		if (lsr & UART_LSR_TEMT)
155147 			break;
156148 
....@@ -165,7 +157,7 @@
165157 
166158 static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
167159 {
168
-	struct dw8250_data *d = p->private_data;
160
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
169161 
170162 	/* Allow the TX to drain before we reconfigure */
171163 	if (offset == UART_LCR)
....@@ -180,7 +172,7 @@
180172 
181173 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
182174 {
183
-	struct dw8250_data *d = p->private_data;
175
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
184176 
185177 	writeb(value, p->membase + (offset << p->regshift));
186178 
....@@ -207,7 +199,7 @@
207199 
208200 static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
209201 {
210
-	struct dw8250_data *d = p->private_data;
202
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
211203 
212204 	value &= 0xff;
213205 	__raw_writeq(value, p->membase + (offset << p->regshift));
....@@ -221,7 +213,7 @@
221213 
222214 static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
223215 {
224
-	struct dw8250_data *d = p->private_data;
216
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
225217 
226218 	writel(value, p->membase + (offset << p->regshift));
227219 
....@@ -238,7 +230,7 @@
238230 
239231 static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
240232 {
241
-	struct dw8250_data *d = p->private_data;
233
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
242234 
243235 	iowrite32be(value, p->membase + (offset << p->regshift));
244236 
....@@ -256,7 +248,7 @@
256248 
257249 static int dw8250_handle_irq(struct uart_port *p)
258250 {
259
-	struct dw8250_data *d = p->private_data;
251
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
260252 	unsigned int iir = p->serial_in(p, UART_IIR);
261253 	unsigned int status, usr, rfl;
262254 	unsigned long flags;
....@@ -292,6 +284,46 @@
292284 	return 0;
293285 }
294286 
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
+
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
+
295327 static void
296328 dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
297329 {
....@@ -307,61 +339,67 @@
307339 static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
308340 			       struct ktermios *old)
309341 {
310
-	unsigned int baud = tty_termios_baud_rate(termios);
311
-	struct dw8250_data *d = p->private_data;
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);
312346 	long rate;
313347 #ifdef CONFIG_ARCH_ROCKCHIP
348
+	unsigned int baud = tty_termios_baud_rate(termios);
314349 	unsigned int rate_temp, diff;
315350 #endif
316351 	int ret;
317352 
318
-	if (IS_ERR(d->clk))
319
-		goto out;
320
-
321353 	clk_disable_unprepare(d->clk);
322354 #ifdef CONFIG_ARCH_ROCKCHIP
323
-	if (baud <= 115200)
324
-		rate = 24000000;
325
-	else if (baud == 230400)
326
-		rate = baud * 16 * 2;
327
-	else if (baud == 1152000)
328
-		rate = baud * 16 * 2;
329
-	else
330
-		rate = baud * 16;
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;
331364 
332
-	ret = clk_set_rate(d->clk, rate);
333
-	rate_temp = clk_get_rate(d->clk);
334
-	diff = rate * 20 / 1000;
335
-	/*
336
-	 * If rate_temp is not equal to rate, is means fractional frequency
337
-	 * division is failed. Then use Integer frequency division, and
338
-	 * the buad rate error must be under -+2%
339
-	 */
340
-	if ((rate_temp < rate) && ((rate - rate_temp) > diff)) {
341
-		ret = clk_set_rate(d->clk, rate + diff);
365
+		ret = clk_set_rate(d->clk, rate);
342366 		rate_temp = clk_get_rate(d->clk);
343
-		if ((rate_temp < rate) && ((rate - rate_temp) > diff))
344
-			dev_info(p->dev, "set rate:%ld, but get rate:%d\n",
345
-				 rate, rate_temp);
346
-		else if ((rate < rate_temp) && ((rate_temp - rate) > diff))
347
-			dev_info(p->dev, "set rate:%ld, but get rate:%d\n",
348
-				 rate, rate_temp);
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;
349385 	}
350386 #else
351
-	rate = clk_round_rate(d->clk, baud * 16);
352
-	if (rate < 0)
353
-		ret = rate;
354
-	else if (rate == 0)
355
-		ret = -ENOENT;
356
-	else
357
-		ret = clk_set_rate(d->clk, rate);
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
+	}
358400 #endif
359401 	clk_prepare_enable(d->clk);
360402 
361
-	if (!ret)
362
-		p->uartclk = rate;
363
-
364
-out:
365403 	p->status &= ~UPSTAT_AUTOCTS;
366404 	if (termios->c_cflag & CRTSCTS)
367405 		p->status |= UPSTAT_AUTOCTS;
....@@ -403,37 +441,6 @@
403441 	return param == chan->device->dev;
404442 }
405443 
406
-/*
407
- * divisor = div(I) + div(F)
408
- * "I" means integer, "F" means fractional
409
- * quot = div(I) = clk / (16 * baud)
410
- * frac = div(F) * 2^dlf_size
411
- *
412
- * let rem = clk % (16 * baud)
413
- * we have: div(F) * (16 * baud) = rem
414
- * so frac = 2^dlf_size * rem / (16 * baud) = (rem << dlf_size) / (16 * baud)
415
- */
416
-static unsigned int dw8250_get_divisor(struct uart_port *p,
417
-				       unsigned int baud,
418
-				       unsigned int *frac)
419
-{
420
-	unsigned int quot, rem, base_baud = baud * 16;
421
-	struct dw8250_data *d = p->private_data;
422
-
423
-	quot = p->uartclk / base_baud;
424
-	rem = p->uartclk % base_baud;
425
-	*frac = DIV_ROUND_CLOSEST(rem << d->dlf_size, base_baud);
426
-
427
-	return quot;
428
-}
429
-
430
-static void dw8250_set_divisor(struct uart_port *p, unsigned int baud,
431
-			       unsigned int quot, unsigned int quot_frac)
432
-{
433
-	dw8250_writel_ext(p, DW_UART_DLF, quot_frac);
434
-	serial8250_do_set_divisor(p, baud, quot, quot_frac);
435
-}
436
-
437444 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
438445 {
439446 	if (p->dev->of_node) {
....@@ -444,6 +451,10 @@
444451 		id = of_alias_get_id(np, "serial");
445452 		if (id >= 0)
446453 			p->line = id;
454
+
455
+		if (IS_ENABLED(CONFIG_ROCKCHIP_MINI_KERNEL))
456
+			return;
457
+
447458 #ifdef CONFIG_64BIT
448459 		if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
449460 			p->serial_in = dw8250_serial_inq;
....@@ -469,82 +480,26 @@
469480 		data->uart_16550_compatible = true;
470481 	}
471482 
483
+	if (IS_ENABLED(CONFIG_ROCKCHIP_MINI_KERNEL))
484
+		return;
485
+
472486 	/* Platforms with iDMA 64-bit */
473487 	if (platform_get_resource_byname(to_platform_device(p->dev),
474488 					 IORESOURCE_MEM, "lpss_priv")) {
475
-		data->dma.rx_param = p->dev->parent;
476
-		data->dma.tx_param = p->dev->parent;
477
-		data->dma.fn = dw8250_idma_filter;
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;
478492 	}
479
-}
480
-
481
-static void dw8250_setup_port(struct uart_port *p)
482
-{
483
-	struct uart_8250_port *up = up_to_u8250p(p);
484
-	u32 reg;
485
-
486
-	/*
487
-	 * If the Component Version Register returns zero, we know that
488
-	 * ADDITIONAL_FEATURES are not enabled. No need to go any further.
489
-	 */
490
-	reg = dw8250_readl_ext(p, DW_UART_UCV);
491
-	if (!reg)
492
-		return;
493
-
494
-	dev_dbg(p->dev, "Designware UART version %c.%c%c\n",
495
-		(reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
496
-
497
-	dw8250_writel_ext(p, DW_UART_DLF, ~0U);
498
-	reg = dw8250_readl_ext(p, DW_UART_DLF);
499
-	dw8250_writel_ext(p, DW_UART_DLF, 0);
500
-
501
-	if (reg) {
502
-		struct dw8250_data *d = p->private_data;
503
-
504
-		d->dlf_size = fls(reg);
505
-		p->get_divisor = dw8250_get_divisor;
506
-		p->set_divisor = dw8250_set_divisor;
507
-	}
508
-
509
-	reg = dw8250_readl_ext(p, DW_UART_CPR);
510
-
511
-#ifdef CONFIG_ARCH_ROCKCHIP
512
-	/*
513
-	 * The UART CPR may be 0 of some rockchip soc,
514
-	 * but it supports fifo and AFC, fifo entry is 32 default.
515
-	 */
516
-	if (reg == 0)
517
-		reg = 0x00023ff2;
518
-#endif
519
-	if (!reg)
520
-		return;
521
-
522
-	/* Select the type based on fifo */
523
-	if (reg & DW_UART_CPR_FIFO_MODE) {
524
-		p->type = PORT_16550A;
525
-		p->flags |= UPF_FIXED_TYPE;
526
-		p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
527
-#ifdef CONFIG_ARCH_ROCKCHIP
528
-		up->tx_loadsz = p->fifosize * 3 / 4;
529
-#endif
530
-		up->capabilities = UART_CAP_FIFO;
531
-	}
532
-
533
-	if (reg & DW_UART_CPR_AFCE_MODE)
534
-		up->capabilities |= UART_CAP_AFE;
535
-
536
-	if (reg & DW_UART_CPR_SIR_MODE)
537
-		up->capabilities |= UART_CAP_IRDA;
538493 }
539494 
540495 static int dw8250_probe(struct platform_device *pdev)
541496 {
542
-	struct uart_8250_port uart = {};
497
+	struct uart_8250_port uart = {}, *up = &uart;
543498 	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
544
-	int irq = platform_get_irq(pdev, 0);
545
-	struct uart_port *p = &uart.port;
499
+	struct uart_port *p = &up->port;
546500 	struct device *dev = &pdev->dev;
547501 	struct dw8250_data *data;
502
+	int irq;
548503 	int err;
549504 	u32 val;
550505 
....@@ -553,11 +508,9 @@
553508 		return -EINVAL;
554509 	}
555510 
556
-	if (irq < 0) {
557
-		if (irq != -EPROBE_DEFER)
558
-			dev_err(dev, "cannot get irq\n");
511
+	irq = platform_get_irq(pdev, 0);
512
+	if (irq < 0)
559513 		return irq;
560
-	}
561514 
562515 	spin_lock_init(&p->lock);
563516 	p->mapbase	= regs->start;
....@@ -581,12 +534,12 @@
581534 	if (!data)
582535 		return -ENOMEM;
583536 
584
-	data->dma.fn = dw8250_fallback_dma_filter;
537
+	data->data.dma.fn = dw8250_fallback_dma_filter;
585538 	data->usr_reg = DW_UART_USR;
539
+	p->private_data = &data->data;
586540 #ifdef CONFIG_ARCH_ROCKCHIP
587541 	data->irq	= irq;
588542 #endif
589
-	p->private_data = data;
590543 
591544 	data->uart_16550_compatible = device_property_read_bool(dev,
592545 						"snps,uart-16550-compatible");
....@@ -637,19 +590,21 @@
637590 	device_property_read_u32(dev, "clock-frequency", &p->uartclk);
638591 
639592 	/* If there is separate baudclk, get the rate from it. */
640
-	data->clk = devm_clk_get(dev, "baudclk");
641
-	if (IS_ERR(data->clk) && PTR_ERR(data->clk) != -EPROBE_DEFER)
642
-		data->clk = devm_clk_get(dev, NULL);
643
-	if (IS_ERR(data->clk) && PTR_ERR(data->clk) == -EPROBE_DEFER)
644
-		return -EPROBE_DEFER;
645
-	if (!IS_ERR_OR_NULL(data->clk)) {
646
-		err = clk_prepare_enable(data->clk);
647
-		if (err)
648
-			dev_warn(dev, "could not enable optional baudclk: %d\n",
649
-				 err);
650
-		else
651
-			p->uartclk = clk_get_rate(data->clk);
652
-	}
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);
653608 
654609 	/* If no clock rate is defined, fail. */
655610 	if (!p->uartclk) {
....@@ -658,17 +613,16 @@
658613 		goto err_clk;
659614 	}
660615 
661
-	data->pclk = devm_clk_get(dev, "apb_pclk");
662
-	if (IS_ERR(data->pclk) && PTR_ERR(data->pclk) == -EPROBE_DEFER) {
663
-		err = -EPROBE_DEFER;
616
+	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
617
+	if (IS_ERR(data->pclk)) {
618
+		err = PTR_ERR(data->pclk);
664619 		goto err_clk;
665620 	}
666
-	if (!IS_ERR(data->pclk)) {
667
-		err = clk_prepare_enable(data->pclk);
668
-		if (err) {
669
-			dev_err(dev, "could not enable apb_pclk\n");
670
-			goto err_clk;
671
-		}
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;
672626 	}
673627 
674628 	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
....@@ -689,22 +643,33 @@
689643 
690644 	/* If we have a valid fifosize, try hooking up DMA */
691645 	if (p->fifosize) {
692
-		data->dma.rxconf.src_maxburst = p->fifosize / 4;
693
-		data->dma.txconf.dst_maxburst = p->fifosize / 4;
694
-		uart.dma = &data->dma;
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;
695649 	}
696650 
697
-	data->line = serial8250_register_8250_port(&uart);
698
-	if (data->line < 0) {
699
-		err = data->line;
651
+	data->data.line = serial8250_register_8250_port(up);
652
+	if (data->data.line < 0) {
653
+		err = data->data.line;
700654 		goto err_reset;
701655 	}
702656 
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
+	}
703669 #ifdef CONFIG_ARCH_ROCKCHIP
704670 	if (data->enable_wakeup)
705671 		device_init_wakeup(&pdev->dev, true);
706672 #endif
707
-
708673 	platform_set_drvdata(pdev, data);
709674 
710675 	pm_runtime_set_active(dev);
....@@ -716,12 +681,10 @@
716681 	reset_control_assert(data->rst);
717682 
718683 err_pclk:
719
-	if (!IS_ERR(data->pclk))
720
-		clk_disable_unprepare(data->pclk);
684
+	clk_disable_unprepare(data->pclk);
721685 
722686 err_clk:
723
-	if (!IS_ERR(data->clk))
724
-		clk_disable_unprepare(data->clk);
687
+	clk_disable_unprepare(data->clk);
725688 
726689 	return err;
727690 }
....@@ -729,26 +692,30 @@
729692 static int dw8250_remove(struct platform_device *pdev)
730693 {
731694 	struct dw8250_data *data = platform_get_drvdata(pdev);
695
+	struct device *dev = &pdev->dev;
732696 
733
-	pm_runtime_get_sync(&pdev->dev);
697
+	pm_runtime_get_sync(dev);
734698 
735
-	serial8250_unregister_port(data->line);
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);
736706 
737707 	reset_control_assert(data->rst);
738708 
739
-	if (!IS_ERR(data->pclk))
740
-		clk_disable_unprepare(data->pclk);
709
+	clk_disable_unprepare(data->pclk);
741710 
742
-	if (!IS_ERR(data->clk))
743
-		clk_disable_unprepare(data->clk);
711
+	clk_disable_unprepare(data->clk);
744712 
713
+	pm_runtime_disable(dev);
714
+	pm_runtime_put_noidle(dev);
745715 #ifdef CONFIG_ARCH_ROCKCHIP
746716 	if (data->enable_wakeup)
747717 		device_init_wakeup(&pdev->dev, false);
748718 #endif
749
-
750
-	pm_runtime_disable(&pdev->dev);
751
-	pm_runtime_put_noidle(&pdev->dev);
752719 
753720 	return 0;
754721 }
....@@ -765,7 +732,7 @@
765732 		return 0;
766733 	}
767734 #endif
768
-	serial8250_suspend_port(data->line);
735
+	serial8250_suspend_port(data->data.line);
769736 
770737 	return 0;
771738 }
....@@ -783,7 +750,7 @@
783750 		return 0;
784751 	}
785752 #endif
786
-	serial8250_resume_port(data->line);
753
+	serial8250_resume_port(data->data.line);
787754 
788755 	return 0;
789756 }
....@@ -794,11 +761,9 @@
794761 {
795762 	struct dw8250_data *data = dev_get_drvdata(dev);
796763 
797
-	if (!IS_ERR(data->clk))
798
-		clk_disable_unprepare(data->clk);
764
+	clk_disable_unprepare(data->clk);
799765 
800
-	if (!IS_ERR(data->pclk))
801
-		clk_disable_unprepare(data->pclk);
766
+	clk_disable_unprepare(data->pclk);
802767 
803768 	return 0;
804769 }
....@@ -807,11 +772,9 @@
807772 {
808773 	struct dw8250_data *data = dev_get_drvdata(dev);
809774 
810
-	if (!IS_ERR(data->pclk))
811
-		clk_prepare_enable(data->pclk);
775
+	clk_prepare_enable(data->pclk);
812776 
813
-	if (!IS_ERR(data->clk))
814
-		clk_prepare_enable(data->clk);
777
+	clk_prepare_enable(data->clk);
815778 
816779 	return 0;
817780 }
....@@ -824,9 +787,11 @@
824787 
825788 static const struct of_device_id dw8250_of_match[] = {
826789 	{ .compatible = "snps,dw-apb-uart" },
790
+#ifndef CONFIG_ROCKCHIP_MINI_KERNEL
827791 	{ .compatible = "cavium,octeon-3860-uart" },
828792 	{ .compatible = "marvell,armada-38x-uart" },
829793 	{ .compatible = "renesas,rzn1-uart" },
794
+#endif
830795 	{ /* Sentinel */ }
831796 };
832797 MODULE_DEVICE_TABLE(of, dw8250_of_match);
....@@ -841,6 +806,7 @@
841806 	{ "APMC0D08", 0},
842807 	{ "AMD0020", 0 },
843808 	{ "AMDI0020", 0 },
809
+	{ "AMDI0022", 0 },
844810 	{ "BRCM2032", 0 },
845811 	{ "HISI0031", 0 },
846812 	{ },