summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/8250/8250_mtk.c
blob: 54051ec7b49927e57b730e48fb0123257ab9f716 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
// SPDX-License-Identifier: GPL-2.0+
/*
 * Mediatek 8250 driver.
 *
 * Copyright (c) 2014 MundoReader S.L.
 * Author: Matthias Brugger <matthias.bgg@gmail.com>
 */
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/console.h>
#include <linux/dma-mapping.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>

#include "8250.h"

#define MTK_UART_HIGHS		0x09	/* Highspeed register */
#define MTK_UART_SAMPLE_COUNT	0x0a	/* Sample count register */
#define MTK_UART_SAMPLE_POINT	0x0b	/* Sample point register */
#define MTK_UART_RATE_FIX	0x0d	/* UART Rate Fix Register */
#define MTK_UART_ESCAPE_DAT	0x10	/* Escape Character register */
#define MTK_UART_ESCAPE_EN	0x11	/* Escape Enable register */
#define MTK_UART_DMA_EN		0x13	/* DMA Enable register */
#define MTK_UART_RXTRI_AD	0x14	/* RX Trigger address */
#define MTK_UART_FRACDIV_L	0x15	/* Fractional divider LSB address */
#define MTK_UART_FRACDIV_M	0x16	/* Fractional divider MSB address */
#define MTK_UART_DEBUG0	0x18
#define MTK_UART_IER_XOFFI	0x20	/* Enable XOFF character interrupt */
#define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */
#define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */

#define MTK_UART_EFR		38	/* I/O: Extended Features Register */
#define MTK_UART_EFR_EN		0x10	/* Enable enhancement feature */
#define MTK_UART_EFR_RTS	0x40	/* Enable hardware rx flow control */
#define MTK_UART_EFR_CTS	0x80	/* Enable hardware tx flow control */
#define MTK_UART_EFR_NO_SW_FC	0x0	/* no sw flow control */
#define MTK_UART_EFR_XON1_XOFF1	0xa	/* XON1/XOFF1 as sw flow control */
#define MTK_UART_EFR_XON2_XOFF2	0x5	/* XON2/XOFF2 as sw flow control */
#define MTK_UART_EFR_SW_FC_MASK	0xf	/* Enable CTS Modem status interrupt */
#define MTK_UART_EFR_HW_FC	(MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)
#define MTK_UART_DMA_EN_TX	0x2
#define MTK_UART_DMA_EN_RX	0x5

#define MTK_UART_ESCAPE_CHAR	0x77	/* Escape char added under sw fc */
#define MTK_UART_RX_SIZE	0x8000
#define MTK_UART_TX_TRIGGER	1
#define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE

#define MTK_UART_XON1		40	/* I/O: Xon character 1 */
#define MTK_UART_XOFF1		42	/* I/O: Xoff character 1 */

#ifdef CONFIG_SERIAL_8250_DMA
enum dma_rx_status {
	DMA_RX_START = 0,
	DMA_RX_RUNNING = 1,
	DMA_RX_SHUTDOWN = 2,
};
#endif

struct mtk8250_data {
	int			line;
	unsigned int		rx_pos;
	unsigned int		clk_count;
	struct clk		*uart_clk;
	struct clk		*bus_clk;
	struct uart_8250_dma	*dma;
#ifdef CONFIG_SERIAL_8250_DMA
	enum dma_rx_status	rx_status;
#endif
	int			rx_wakeup_irq;
};

/* flow control mode */
enum {
	MTK_UART_FC_NONE,
	MTK_UART_FC_SW,
	MTK_UART_FC_HW,
};

#ifdef CONFIG_SERIAL_8250_DMA
static void mtk8250_rx_dma(struct uart_8250_port *up);

static void mtk8250_dma_rx_complete(void *param)
{
	struct uart_8250_port *up = param;
	struct uart_8250_dma *dma = up->dma;
	struct mtk8250_data *data = up->port.private_data;
	struct tty_port *tty_port = &up->port.state->port;
	struct dma_tx_state state;
	int copied, total, cnt;
	unsigned char *ptr;
	unsigned long flags;

	if (data->rx_status == DMA_RX_SHUTDOWN)
		return;

	spin_lock_irqsave(&up->port.lock, flags);

	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
	total = dma->rx_size - state.residue;
	cnt = total;

	if ((data->rx_pos + cnt) > dma->rx_size)
		cnt = dma->rx_size - data->rx_pos;

	ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
	copied = tty_insert_flip_string(tty_port, ptr, cnt);
	data->rx_pos += cnt;

	if (total > cnt) {
		ptr = (unsigned char *)(dma->rx_buf);
		cnt = total - cnt;
		copied += tty_insert_flip_string(tty_port, ptr, cnt);
		data->rx_pos = cnt;
	}

	up->port.icount.rx += copied;

	tty_flip_buffer_push(tty_port);

	mtk8250_rx_dma(up);

	spin_unlock_irqrestore(&up->port.lock, flags);
}

static void mtk8250_rx_dma(struct uart_8250_port *up)
{
	struct uart_8250_dma *dma = up->dma;
	struct dma_async_tx_descriptor	*desc;

	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
					   dma->rx_size, DMA_DEV_TO_MEM,
					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!desc) {
		pr_err("failed to prepare rx slave single\n");
		return;
	}

	desc->callback = mtk8250_dma_rx_complete;
	desc->callback_param = up;

	dma->rx_cookie = dmaengine_submit(desc);

	dma_async_issue_pending(dma->rxchan);
}

static void mtk8250_dma_enable(struct uart_8250_port *up)
{
	struct uart_8250_dma *dma = up->dma;
	struct mtk8250_data *data = up->port.private_data;
	int lcr = serial_in(up, UART_LCR);

	if (data->rx_status != DMA_RX_START)
		return;

	dma->rxconf.src_port_window_size	= dma->rx_size;
	dma->rxconf.src_addr				= dma->rx_addr;

	dma->txconf.dst_port_window_size	= UART_XMIT_SIZE;
	dma->txconf.dst_addr				= dma->tx_addr;

	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
		UART_FCR_CLEAR_XMIT);
	serial_out(up, MTK_UART_DMA_EN,
		   MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
	serial_out(up, UART_LCR, lcr);

	if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
		pr_err("failed to configure rx dma channel\n");
	if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
		pr_err("failed to configure tx dma channel\n");

	data->rx_status = DMA_RX_RUNNING;
	data->rx_pos = 0;
	mtk8250_rx_dma(up);
}
#endif

static int mtk8250_startup(struct uart_port *port)
{
#ifdef CONFIG_SERIAL_8250_DMA
	struct uart_8250_port *up = up_to_u8250p(port);
	struct mtk8250_data *data = port->private_data;

	/* disable DMA for console */
	if (uart_console(port))
		up->dma = NULL;

	if (up->dma) {
		data->rx_status = DMA_RX_START;
		uart_circ_clear(&port->state->xmit);
	}
#endif
	memset(&port->icount, 0, sizeof(port->icount));

	return serial8250_do_startup(port);
}

static void mtk8250_shutdown(struct uart_port *port)
{
#ifdef CONFIG_SERIAL_8250_DMA
	struct uart_8250_port *up = up_to_u8250p(port);
	struct mtk8250_data *data = port->private_data;

	if (up->dma)
		data->rx_status = DMA_RX_SHUTDOWN;
#endif

	return serial8250_do_shutdown(port);
}

static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
{
	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
}

static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
{
	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
}

static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
{
	struct uart_port *port = &up->port;
	int lcr = serial_in(up, UART_LCR);

	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
	serial_out(up, UART_LCR, lcr);
	lcr = serial_in(up, UART_LCR);

	switch (mode) {
	case MTK_UART_FC_NONE:
		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
		serial_out(up, MTK_UART_EFR, serial_in(up, MTK_UART_EFR) &
			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
		serial_out(up, UART_LCR, lcr);
		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
			MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);
		break;

	case MTK_UART_FC_HW:
		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
		serial_out(up, UART_MCR, UART_MCR_RTS);
		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

		/*enable hw flow control*/
		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_HW_FC |
			(serial_in(up, MTK_UART_EFR) &
			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));

		serial_out(up, UART_LCR, lcr);
		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);
		mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);
		break;

	case MTK_UART_FC_SW:	/*MTK software flow control */
		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
		serial_out(up, MTK_UART_ESCAPE_EN, 0x01);
		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);

		/*enable sw flow control */
		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
			(serial_in(up, MTK_UART_EFR) &
			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));

		serial_out(up, MTK_UART_XON1, START_CHAR(port->state->port.tty));
		serial_out(up, MTK_UART_XOFF1, STOP_CHAR(port->state->port.tty));
		serial_out(up, UART_LCR, lcr);
		mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
		mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
		break;
	default:
		break;
	}
}

static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
			struct ktermios *old)
{
	static const unsigned short fraction_L_mapping[] = {
		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
	};
	static const unsigned short fraction_M_mapping[] = {
		0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
	};
	struct uart_8250_port *up = up_to_u8250p(port);
	unsigned int baud, quot, fraction;
	unsigned long flags;
	int mode;

#ifdef CONFIG_SERIAL_8250_DMA
	if (up->dma) {
		if (uart_console(port)) {
			devm_kfree(up->port.dev, up->dma);
			up->dma = NULL;
		} else {
			mtk8250_dma_enable(up);
		}
	}
#endif

	/*
	 * Store the requested baud rate before calling the generic 8250
	 * set_termios method. Standard 8250 port expects bauds to be
	 * no higher than (uartclk / 16) so the baud will be clamped if it
	 * gets out of that bound. Mediatek 8250 port supports speed
	 * higher than that, therefore we'll get original baud rate back
	 * after calling the generic set_termios method and recalculate
	 * the speed later in this method.
	 */
	baud = tty_termios_baud_rate(termios);

	serial8250_do_set_termios(port, termios, NULL);

	tty_termios_encode_baud_rate(termios, baud, baud);

	/*
	 * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
	 *
	 * We need to recalcualte the quot register, as the claculation depends
	 * on the vaule in the highspeed register.
	 *
	 * Some baudrates are not supported by the chip, so we use the next
	 * lower rate supported and update termios c_flag.
	 *
	 * If highspeed register is set to 3, we need to specify sample count
	 * and sample point to increase accuracy. If not, we reset the
	 * registers to their default values.
	 */
	baud = uart_get_baud_rate(port, termios, old,
				  port->uartclk / 16 / UART_DIV_MAX,
				  port->uartclk);

	if (baud < 115200) {
		serial_port_out(port, MTK_UART_HIGHS, 0x0);
		quot = uart_get_divisor(port, baud);
	} else {
		serial_port_out(port, MTK_UART_HIGHS, 0x3);
		quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
	}

	/*
	 * Ok, we're now changing the port state.  Do it with
	 * interrupts disabled.
	 */
	spin_lock_irqsave(&port->lock, flags);

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	/* set DLAB we have cval saved in up->lcr from the call to the core */
	serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
	serial_dl_write(up, quot);

	/* reset DLAB */
	serial_port_out(port, UART_LCR, up->lcr);

	if (baud >= 115200) {
		unsigned int tmp;

		tmp = (port->uartclk / (baud *  quot)) - 1;
		serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
		serial_port_out(port, MTK_UART_SAMPLE_POINT,
					(tmp >> 1) - 1);

		/*count fraction to set fractoin register */
		fraction = ((port->uartclk  * 100) / baud / quot) % 100;
		fraction = DIV_ROUND_CLOSEST(fraction, 10);
		serial_port_out(port, MTK_UART_FRACDIV_L,
						fraction_L_mapping[fraction]);
		serial_port_out(port, MTK_UART_FRACDIV_M,
						fraction_M_mapping[fraction]);
	} else {
		serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
		serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
		serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
		serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
	}

	if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))
		mode = MTK_UART_FC_HW;
	else if (termios->c_iflag & CRTSCTS)
		mode = MTK_UART_FC_SW;
	else
		mode = MTK_UART_FC_NONE;

	mtk8250_set_flow_ctrl(up, mode);

	if (uart_console(port))
		up->port.cons->cflag = termios->c_cflag;

	spin_unlock_irqrestore(&port->lock, flags);
	/* Don't rewrite B0 */
	if (tty_termios_baud_rate(termios))
		tty_termios_encode_baud_rate(termios, baud, baud);
}

static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
{
	struct mtk8250_data *data = dev_get_drvdata(dev);
	struct uart_8250_port *up = serial8250_get_port(data->line);

	/* wait until UART in idle status */
	while
		(serial_in(up, MTK_UART_DEBUG0));

	if (data->clk_count == 0U) {
		dev_dbg(dev, "%s clock count is 0\n", __func__);
	} else {
		clk_disable_unprepare(data->bus_clk);
		data->clk_count--;
	}

	return 0;
}

static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
{
	struct mtk8250_data *data = dev_get_drvdata(dev);
	int err;

	if (data->clk_count > 0U) {
		dev_dbg(dev, "%s clock count is %d\n", __func__,
			data->clk_count);
	} else {
		err = clk_prepare_enable(data->bus_clk);
		if (err) {
			dev_warn(dev, "Can't enable bus clock\n");
			return err;
		}
		data->clk_count++;
	}

	return 0;
}

static void
mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
{
	if (!state)
		if (!mtk8250_runtime_resume(port->dev))
			pm_runtime_get_sync(port->dev);

	serial8250_do_pm(port, state, old);

	if (state)
		if (!pm_runtime_put_sync_suspend(port->dev))
			mtk8250_runtime_suspend(port->dev);
}

#ifdef CONFIG_SERIAL_8250_DMA
static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
{
	return false;
}
#endif

static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
			   struct mtk8250_data *data)
{
#ifdef CONFIG_SERIAL_8250_DMA
	int dmacnt;
#endif

	data->uart_clk = devm_clk_get(&pdev->dev, "baud");
	if (IS_ERR(data->uart_clk)) {
		/*
		 * For compatibility with older device trees try unnamed
		 * clk when no baud clk can be found.
		 */
		data->uart_clk = devm_clk_get(&pdev->dev, NULL);
		if (IS_ERR(data->uart_clk)) {
			dev_warn(&pdev->dev, "Can't get uart clock\n");
			return PTR_ERR(data->uart_clk);
		}

		return 0;
	}

	data->bus_clk = devm_clk_get(&pdev->dev, "bus");
	if (IS_ERR(data->bus_clk))
		return PTR_ERR(data->bus_clk);

	data->dma = NULL;
#ifdef CONFIG_SERIAL_8250_DMA
	dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
	if (dmacnt == 2) {
		data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
					 GFP_KERNEL);
		if (!data->dma)
			return -ENOMEM;

		data->dma->fn = mtk8250_dma_filter;
		data->dma->rx_size = MTK_UART_RX_SIZE;
		data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
		data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
	}
#endif

	return 0;
}

static int mtk8250_probe(struct platform_device *pdev)
{
	struct uart_8250_port uart = {};
	struct mtk8250_data *data;
	struct resource *regs;
	int irq, err;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs) {
		dev_err(&pdev->dev, "no registers defined\n");
		return -EINVAL;
	}

	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
					 resource_size(regs));
	if (!uart.port.membase)
		return -ENOMEM;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->clk_count = 0;

	if (pdev->dev.of_node) {
		err = mtk8250_probe_of(pdev, &uart.port, data);
		if (err)
			return err;
	} else
		return -ENODEV;

	spin_lock_init(&uart.port.lock);
	uart.port.mapbase = regs->start;
	uart.port.irq = irq;
	uart.port.pm = mtk8250_do_pm;
	uart.port.type = PORT_16550;
	uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
	uart.port.dev = &pdev->dev;
	uart.port.iotype = UPIO_MEM32;
	uart.port.regshift = 2;
	uart.port.private_data = data;
	uart.port.shutdown = mtk8250_shutdown;
	uart.port.startup = mtk8250_startup;
	uart.port.set_termios = mtk8250_set_termios;
	uart.port.uartclk = clk_get_rate(data->uart_clk);
#ifdef CONFIG_SERIAL_8250_DMA
	if (data->dma)
		uart.dma = data->dma;
#endif

	/* Disable Rate Fix function */
	writel(0x0, uart.port.membase +
			(MTK_UART_RATE_FIX << uart.port.regshift));

	platform_set_drvdata(pdev, data);

	pm_runtime_enable(&pdev->dev);
	err = mtk8250_runtime_resume(&pdev->dev);
	if (err)
		goto err_pm_disable;

	data->line = serial8250_register_8250_port(&uart);
	if (data->line < 0) {
		err = data->line;
		goto err_pm_disable;
	}

	data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);

	return 0;

err_pm_disable:
	pm_runtime_disable(&pdev->dev);

	return err;
}

static int mtk8250_remove(struct platform_device *pdev)
{
	struct mtk8250_data *data = platform_get_drvdata(pdev);

	pm_runtime_get_sync(&pdev->dev);

	serial8250_unregister_port(data->line);

	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);

	if (!pm_runtime_status_suspended(&pdev->dev))
		mtk8250_runtime_suspend(&pdev->dev);

	return 0;
}

static int __maybe_unused mtk8250_suspend(struct device *dev)
{
	struct mtk8250_data *data = dev_get_drvdata(dev);
	int irq = data->rx_wakeup_irq;
	int err;

	serial8250_suspend_port(data->line);

	pinctrl_pm_select_sleep_state(dev);
	if (irq >= 0) {
		err = enable_irq_wake(irq);
		if (err) {
			dev_err(dev,
				"failed to enable irq wake on IRQ %d: %d\n",
				irq, err);
			pinctrl_pm_select_default_state(dev);
			serial8250_resume_port(data->line);
			return err;
		}
	}

	return 0;
}

static int __maybe_unused mtk8250_resume(struct device *dev)
{
	struct mtk8250_data *data = dev_get_drvdata(dev);
	int irq = data->rx_wakeup_irq;

	if (irq >= 0)
		disable_irq_wake(irq);
	pinctrl_pm_select_default_state(dev);

	serial8250_resume_port(data->line);

	return 0;
}

static const struct dev_pm_ops mtk8250_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
	SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
				NULL)
};

static const struct of_device_id mtk8250_of_match[] = {
	{ .compatible = "mediatek,mt6577-uart" },
	{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, mtk8250_of_match);

static struct platform_driver mtk8250_platform_driver = {
	.driver = {
		.name		= "mt6577-uart",
		.pm		= &mtk8250_pm_ops,
		.of_match_table	= mtk8250_of_match,
	},
	.probe			= mtk8250_probe,
	.remove			= mtk8250_remove,
};
module_platform_driver(mtk8250_platform_driver);

#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init early_mtk8250_setup(struct earlycon_device *device,
					const char *options)
{
	if (!device->port.membase)
		return -ENODEV;

	device->port.iotype = UPIO_MEM32;
	device->port.regshift = 2;

	return early_serial8250_setup(device, NULL);
}

OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
#endif

MODULE_AUTHOR("Matthias Brugger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Mediatek 8250 serial port driver");