1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Mediatek 8250 driver.
4 *
5 * Copyright (c) 2014 MundoReader S.L.
6 * Author: Matthias Brugger <matthias.bgg@gmail.com>
7 */
8#include <linux/clk.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of_irq.h>
12#include <linux/of_platform.h>
13#include <linux/pinctrl/consumer.h>
14#include <linux/platform_device.h>
15#include <linux/pm_runtime.h>
16#include <linux/serial_8250.h>
17#include <linux/serial_reg.h>
18#include <linux/console.h>
19#include <linux/dma-mapping.h>
20#include <linux/tty.h>
21#include <linux/tty_flip.h>
22
23#include "8250.h"
24
25#define MTK_UART_HIGHS		0x09	/* Highspeed register */
26#define MTK_UART_SAMPLE_COUNT	0x0a	/* Sample count register */
27#define MTK_UART_SAMPLE_POINT	0x0b	/* Sample point register */
28#define MTK_UART_RATE_FIX	0x0d	/* UART Rate Fix Register */
29#define MTK_UART_ESCAPE_DAT	0x10	/* Escape Character register */
30#define MTK_UART_ESCAPE_EN	0x11	/* Escape Enable register */
31#define MTK_UART_DMA_EN		0x13	/* DMA Enable register */
32#define MTK_UART_RXTRI_AD	0x14	/* RX Trigger address */
33#define MTK_UART_FRACDIV_L	0x15	/* Fractional divider LSB address */
34#define MTK_UART_FRACDIV_M	0x16	/* Fractional divider MSB address */
35#define MTK_UART_DEBUG0	0x18
36#define MTK_UART_IER_XOFFI	0x20	/* Enable XOFF character interrupt */
37#define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */
38#define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */
39
40#define MTK_UART_EFR		38	/* I/O: Extended Features Register */
41#define MTK_UART_EFR_EN		0x10	/* Enable enhancement feature */
42#define MTK_UART_EFR_RTS	0x40	/* Enable hardware rx flow control */
43#define MTK_UART_EFR_CTS	0x80	/* Enable hardware tx flow control */
44#define MTK_UART_EFR_NO_SW_FC	0x0	/* no sw flow control */
45#define MTK_UART_EFR_XON1_XOFF1	0xa	/* XON1/XOFF1 as sw flow control */
46#define MTK_UART_EFR_XON2_XOFF2	0x5	/* XON2/XOFF2 as sw flow control */
47#define MTK_UART_EFR_SW_FC_MASK	0xf	/* Enable CTS Modem status interrupt */
48#define MTK_UART_EFR_HW_FC	(MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)
49#define MTK_UART_DMA_EN_TX	0x2
50#define MTK_UART_DMA_EN_RX	0x5
51
52#define MTK_UART_ESCAPE_CHAR	0x77	/* Escape char added under sw fc */
53#define MTK_UART_RX_SIZE	0x8000
54#define MTK_UART_TX_TRIGGER	1
55#define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE
56
57#define MTK_UART_XON1		40	/* I/O: Xon character 1 */
58#define MTK_UART_XOFF1		42	/* I/O: Xoff character 1 */
59
60#ifdef CONFIG_SERIAL_8250_DMA
61enum dma_rx_status {
62	DMA_RX_START = 0,
63	DMA_RX_RUNNING = 1,
64	DMA_RX_SHUTDOWN = 2,
65};
66#endif
67
68struct mtk8250_data {
69	int			line;
70	unsigned int		rx_pos;
71	unsigned int		clk_count;
72	struct clk		*uart_clk;
73	struct clk		*bus_clk;
74	struct uart_8250_dma	*dma;
75#ifdef CONFIG_SERIAL_8250_DMA
76	enum dma_rx_status	rx_status;
77#endif
78	int			rx_wakeup_irq;
79};
80
81/* flow control mode */
82enum {
83	MTK_UART_FC_NONE,
84	MTK_UART_FC_SW,
85	MTK_UART_FC_HW,
86};
87
88#ifdef CONFIG_SERIAL_8250_DMA
89static void mtk8250_rx_dma(struct uart_8250_port *up);
90
91static void mtk8250_dma_rx_complete(void *param)
92{
93	struct uart_8250_port *up = param;
94	struct uart_8250_dma *dma = up->dma;
95	struct mtk8250_data *data = up->port.private_data;
96	struct tty_port *tty_port = &up->port.state->port;
97	struct dma_tx_state state;
98	int copied, total, cnt;
99	unsigned char *ptr;
100	unsigned long flags;
101
102	if (data->rx_status == DMA_RX_SHUTDOWN)
103		return;
104
105	spin_lock_irqsave(&up->port.lock, flags);
106
107	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
108	total = dma->rx_size - state.residue;
109	cnt = total;
110
111	if ((data->rx_pos + cnt) > dma->rx_size)
112		cnt = dma->rx_size - data->rx_pos;
113
114	ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
115	copied = tty_insert_flip_string(tty_port, ptr, cnt);
116	data->rx_pos += cnt;
117
118	if (total > cnt) {
119		ptr = (unsigned char *)(dma->rx_buf);
120		cnt = total - cnt;
121		copied += tty_insert_flip_string(tty_port, ptr, cnt);
122		data->rx_pos = cnt;
123	}
124
125	up->port.icount.rx += copied;
126
127	tty_flip_buffer_push(tty_port);
128
129	mtk8250_rx_dma(up);
130
131	spin_unlock_irqrestore(&up->port.lock, flags);
132}
133
134static void mtk8250_rx_dma(struct uart_8250_port *up)
135{
136	struct uart_8250_dma *dma = up->dma;
137	struct dma_async_tx_descriptor	*desc;
138
139	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
140					   dma->rx_size, DMA_DEV_TO_MEM,
141					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
142	if (!desc) {
143		pr_err("failed to prepare rx slave single\n");
144		return;
145	}
146
147	desc->callback = mtk8250_dma_rx_complete;
148	desc->callback_param = up;
149
150	dma->rx_cookie = dmaengine_submit(desc);
151
152	dma_async_issue_pending(dma->rxchan);
153}
154
155static void mtk8250_dma_enable(struct uart_8250_port *up)
156{
157	struct uart_8250_dma *dma = up->dma;
158	struct mtk8250_data *data = up->port.private_data;
159	int lcr = serial_in(up, UART_LCR);
160
161	if (data->rx_status != DMA_RX_START)
162		return;
163
164	dma->rxconf.src_port_window_size	= dma->rx_size;
165	dma->rxconf.src_addr				= dma->rx_addr;
166
167	dma->txconf.dst_port_window_size	= UART_XMIT_SIZE;
168	dma->txconf.dst_addr				= dma->tx_addr;
169
170	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
171		UART_FCR_CLEAR_XMIT);
172	serial_out(up, MTK_UART_DMA_EN,
173		   MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
174
175	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
176	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
177	serial_out(up, UART_LCR, lcr);
178
179	if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
180		pr_err("failed to configure rx dma channel\n");
181	if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
182		pr_err("failed to configure tx dma channel\n");
183
184	data->rx_status = DMA_RX_RUNNING;
185	data->rx_pos = 0;
186	mtk8250_rx_dma(up);
187}
188#endif
189
190static int mtk8250_startup(struct uart_port *port)
191{
192#ifdef CONFIG_SERIAL_8250_DMA
193	struct uart_8250_port *up = up_to_u8250p(port);
194	struct mtk8250_data *data = port->private_data;
195
196	/* disable DMA for console */
197	if (uart_console(port))
198		up->dma = NULL;
199
200	if (up->dma) {
201		data->rx_status = DMA_RX_START;
202		uart_circ_clear(&port->state->xmit);
203	}
204#endif
205	memset(&port->icount, 0, sizeof(port->icount));
206
207	return serial8250_do_startup(port);
208}
209
210static void mtk8250_shutdown(struct uart_port *port)
211{
212#ifdef CONFIG_SERIAL_8250_DMA
213	struct uart_8250_port *up = up_to_u8250p(port);
214	struct mtk8250_data *data = port->private_data;
215
216	if (up->dma)
217		data->rx_status = DMA_RX_SHUTDOWN;
218#endif
219
220	return serial8250_do_shutdown(port);
221}
222
223static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
224{
225	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
226}
227
228static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
229{
230	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
231}
232
233static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
234{
235	struct uart_port *port = &up->port;
236	int lcr = serial_in(up, UART_LCR);
237
238	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
239	serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
240	serial_out(up, UART_LCR, lcr);
241	lcr = serial_in(up, UART_LCR);
242
243	switch (mode) {
244	case MTK_UART_FC_NONE:
245		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
246		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
247		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
248		serial_out(up, MTK_UART_EFR, serial_in(up, MTK_UART_EFR) &
249			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
250		serial_out(up, UART_LCR, lcr);
251		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
252			MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);
253		break;
254
255	case MTK_UART_FC_HW:
256		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
257		serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
258		serial_out(up, UART_MCR, UART_MCR_RTS);
259		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
260
261		/*enable hw flow control*/
262		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_HW_FC |
263			(serial_in(up, MTK_UART_EFR) &
264			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
265
266		serial_out(up, UART_LCR, lcr);
267		mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);
268		mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);
269		break;
270
271	case MTK_UART_FC_SW:	/*MTK software flow control */
272		serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
273		serial_out(up, MTK_UART_ESCAPE_EN, 0x01);
274		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
275
276		/*enable sw flow control */
277		serial_out(up, MTK_UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
278			(serial_in(up, MTK_UART_EFR) &
279			(~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
280
281		serial_out(up, MTK_UART_XON1, START_CHAR(port->state->port.tty));
282		serial_out(up, MTK_UART_XOFF1, STOP_CHAR(port->state->port.tty));
283		serial_out(up, UART_LCR, lcr);
284		mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
285		mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
286		break;
287	default:
288		break;
289	}
290}
291
292static void
293mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
294			struct ktermios *old)
295{
296	unsigned short fraction_L_mapping[] = {
297		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
298	};
299	unsigned short fraction_M_mapping[] = {
300		0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
301	};
302	struct uart_8250_port *up = up_to_u8250p(port);
303	unsigned int baud, quot, fraction;
304	unsigned long flags;
305	int mode;
306
307#ifdef CONFIG_SERIAL_8250_DMA
308	if (up->dma) {
309		if (uart_console(port)) {
310			devm_kfree(up->port.dev, up->dma);
311			up->dma = NULL;
312		} else {
313			mtk8250_dma_enable(up);
314		}
315	}
316#endif
317
318	/*
319	 * Store the requested baud rate before calling the generic 8250
320	 * set_termios method. Standard 8250 port expects bauds to be
321	 * no higher than (uartclk / 16) so the baud will be clamped if it
322	 * gets out of that bound. Mediatek 8250 port supports speed
323	 * higher than that, therefore we'll get original baud rate back
324	 * after calling the generic set_termios method and recalculate
325	 * the speed later in this method.
326	 */
327	baud = tty_termios_baud_rate(termios);
328
329	serial8250_do_set_termios(port, termios, NULL);
330
331	tty_termios_encode_baud_rate(termios, baud, baud);
332
333	/*
334	 * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
335	 *
336	 * We need to recalcualte the quot register, as the claculation depends
337	 * on the vaule in the highspeed register.
338	 *
339	 * Some baudrates are not supported by the chip, so we use the next
340	 * lower rate supported and update termios c_flag.
341	 *
342	 * If highspeed register is set to 3, we need to specify sample count
343	 * and sample point to increase accuracy. If not, we reset the
344	 * registers to their default values.
345	 */
346	baud = uart_get_baud_rate(port, termios, old,
347				  port->uartclk / 16 / UART_DIV_MAX,
348				  port->uartclk);
349
350	if (baud < 115200) {
351		serial_port_out(port, MTK_UART_HIGHS, 0x0);
352		quot = uart_get_divisor(port, baud);
353	} else {
354		serial_port_out(port, MTK_UART_HIGHS, 0x3);
355		quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
356	}
357
358	/*
359	 * Ok, we're now changing the port state.  Do it with
360	 * interrupts disabled.
361	 */
362	spin_lock_irqsave(&port->lock, flags);
363
364	/*
365	 * Update the per-port timeout.
366	 */
367	uart_update_timeout(port, termios->c_cflag, baud);
368
369	/* set DLAB we have cval saved in up->lcr from the call to the core */
370	serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
371	serial_dl_write(up, quot);
372
373	/* reset DLAB */
374	serial_port_out(port, UART_LCR, up->lcr);
375
376	if (baud >= 115200) {
377		unsigned int tmp;
378
379		tmp = (port->uartclk / (baud *  quot)) - 1;
380		serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
381		serial_port_out(port, MTK_UART_SAMPLE_POINT,
382					(tmp >> 1) - 1);
383
384		/*count fraction to set fractoin register */
385		fraction = ((port->uartclk  * 100) / baud / quot) % 100;
386		fraction = DIV_ROUND_CLOSEST(fraction, 10);
387		serial_port_out(port, MTK_UART_FRACDIV_L,
388						fraction_L_mapping[fraction]);
389		serial_port_out(port, MTK_UART_FRACDIV_M,
390						fraction_M_mapping[fraction]);
391	} else {
392		serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
393		serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
394		serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
395		serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
396	}
397
398	if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))
399		mode = MTK_UART_FC_HW;
400	else if (termios->c_iflag & CRTSCTS)
401		mode = MTK_UART_FC_SW;
402	else
403		mode = MTK_UART_FC_NONE;
404
405	mtk8250_set_flow_ctrl(up, mode);
406
407	if (uart_console(port))
408		up->port.cons->cflag = termios->c_cflag;
409
410	spin_unlock_irqrestore(&port->lock, flags);
411	/* Don't rewrite B0 */
412	if (tty_termios_baud_rate(termios))
413		tty_termios_encode_baud_rate(termios, baud, baud);
414}
415
416static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
417{
418	struct mtk8250_data *data = dev_get_drvdata(dev);
419	struct uart_8250_port *up = serial8250_get_port(data->line);
420
421	/* wait until UART in idle status */
422	while
423		(serial_in(up, MTK_UART_DEBUG0));
424
425	if (data->clk_count == 0U) {
426		dev_dbg(dev, "%s clock count is 0\n", __func__);
427	} else {
428		clk_disable_unprepare(data->bus_clk);
429		data->clk_count--;
430	}
431
432	return 0;
433}
434
435static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
436{
437	struct mtk8250_data *data = dev_get_drvdata(dev);
438	int err;
439
440	if (data->clk_count > 0U) {
441		dev_dbg(dev, "%s clock count is %d\n", __func__,
442			data->clk_count);
443	} else {
444		err = clk_prepare_enable(data->bus_clk);
445		if (err) {
446			dev_warn(dev, "Can't enable bus clock\n");
447			return err;
448		}
449		data->clk_count++;
450	}
451
452	return 0;
453}
454
455static void
456mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
457{
458	if (!state)
459		if (!mtk8250_runtime_resume(port->dev))
460			pm_runtime_get_sync(port->dev);
461
462	serial8250_do_pm(port, state, old);
463
464	if (state)
465		if (!pm_runtime_put_sync_suspend(port->dev))
466			mtk8250_runtime_suspend(port->dev);
467}
468
469#ifdef CONFIG_SERIAL_8250_DMA
470static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
471{
472	return false;
473}
474#endif
475
476static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
477			   struct mtk8250_data *data)
478{
479#ifdef CONFIG_SERIAL_8250_DMA
480	int dmacnt;
481#endif
482
483	data->uart_clk = devm_clk_get(&pdev->dev, "baud");
484	if (IS_ERR(data->uart_clk)) {
485		/*
486		 * For compatibility with older device trees try unnamed
487		 * clk when no baud clk can be found.
488		 */
489		data->uart_clk = devm_clk_get(&pdev->dev, NULL);
490		if (IS_ERR(data->uart_clk)) {
491			dev_warn(&pdev->dev, "Can't get uart clock\n");
492			return PTR_ERR(data->uart_clk);
493		}
494
495		return 0;
496	}
497
498	data->bus_clk = devm_clk_get(&pdev->dev, "bus");
499	if (IS_ERR(data->bus_clk))
500		return PTR_ERR(data->bus_clk);
501
502	data->dma = NULL;
503#ifdef CONFIG_SERIAL_8250_DMA
504	dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
505	if (dmacnt == 2) {
506		data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
507					 GFP_KERNEL);
508		if (!data->dma)
509			return -ENOMEM;
510
511		data->dma->fn = mtk8250_dma_filter;
512		data->dma->rx_size = MTK_UART_RX_SIZE;
513		data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
514		data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
515	}
516#endif
517
518	return 0;
519}
520
521static int mtk8250_probe(struct platform_device *pdev)
522{
523	struct uart_8250_port uart = {};
524	struct mtk8250_data *data;
525	struct resource *regs;
526	int irq, err;
527
528	irq = platform_get_irq(pdev, 0);
529	if (irq < 0)
530		return irq;
531
532	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
533	if (!regs) {
534		dev_err(&pdev->dev, "no registers defined\n");
535		return -EINVAL;
536	}
537
538	uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
539					 resource_size(regs));
540	if (!uart.port.membase)
541		return -ENOMEM;
542
543	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
544	if (!data)
545		return -ENOMEM;
546
547	data->clk_count = 0;
548
549	if (pdev->dev.of_node) {
550		err = mtk8250_probe_of(pdev, &uart.port, data);
551		if (err)
552			return err;
553	} else
554		return -ENODEV;
555
556	spin_lock_init(&uart.port.lock);
557	uart.port.mapbase = regs->start;
558	uart.port.irq = irq;
559	uart.port.pm = mtk8250_do_pm;
560	uart.port.type = PORT_16550;
561	uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
562	uart.port.dev = &pdev->dev;
563	uart.port.iotype = UPIO_MEM32;
564	uart.port.regshift = 2;
565	uart.port.private_data = data;
566	uart.port.shutdown = mtk8250_shutdown;
567	uart.port.startup = mtk8250_startup;
568	uart.port.set_termios = mtk8250_set_termios;
569	uart.port.uartclk = clk_get_rate(data->uart_clk);
570#ifdef CONFIG_SERIAL_8250_DMA
571	if (data->dma)
572		uart.dma = data->dma;
573#endif
574
575	/* Disable Rate Fix function */
576	writel(0x0, uart.port.membase +
577			(MTK_UART_RATE_FIX << uart.port.regshift));
578
579	platform_set_drvdata(pdev, data);
580
581	pm_runtime_enable(&pdev->dev);
582	err = mtk8250_runtime_resume(&pdev->dev);
583	if (err)
584		goto err_pm_disable;
585
586	data->line = serial8250_register_8250_port(&uart);
587	if (data->line < 0) {
588		err = data->line;
589		goto err_pm_disable;
590	}
591
592	data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);
593
594	return 0;
595
596err_pm_disable:
597	pm_runtime_disable(&pdev->dev);
598
599	return err;
600}
601
602static int mtk8250_remove(struct platform_device *pdev)
603{
604	struct mtk8250_data *data = platform_get_drvdata(pdev);
605
606	pm_runtime_get_sync(&pdev->dev);
607
608	serial8250_unregister_port(data->line);
609
610	pm_runtime_disable(&pdev->dev);
611	pm_runtime_put_noidle(&pdev->dev);
612
613	if (!pm_runtime_status_suspended(&pdev->dev))
614		mtk8250_runtime_suspend(&pdev->dev);
615
616	return 0;
617}
618
619static int __maybe_unused mtk8250_suspend(struct device *dev)
620{
621	struct mtk8250_data *data = dev_get_drvdata(dev);
622	int irq = data->rx_wakeup_irq;
623	int err;
624
625	serial8250_suspend_port(data->line);
626
627	pinctrl_pm_select_sleep_state(dev);
628	if (irq >= 0) {
629		err = enable_irq_wake(irq);
630		if (err) {
631			dev_err(dev,
632				"failed to enable irq wake on IRQ %d: %d\n",
633				irq, err);
634			pinctrl_pm_select_default_state(dev);
635			serial8250_resume_port(data->line);
636			return err;
637		}
638	}
639
640	return 0;
641}
642
643static int __maybe_unused mtk8250_resume(struct device *dev)
644{
645	struct mtk8250_data *data = dev_get_drvdata(dev);
646	int irq = data->rx_wakeup_irq;
647
648	if (irq >= 0)
649		disable_irq_wake(irq);
650	pinctrl_pm_select_default_state(dev);
651
652	serial8250_resume_port(data->line);
653
654	return 0;
655}
656
657static const struct dev_pm_ops mtk8250_pm_ops = {
658	SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
659	SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
660				NULL)
661};
662
663static const struct of_device_id mtk8250_of_match[] = {
664	{ .compatible = "mediatek,mt6577-uart" },
665	{ /* Sentinel */ }
666};
667MODULE_DEVICE_TABLE(of, mtk8250_of_match);
668
669static struct platform_driver mtk8250_platform_driver = {
670	.driver = {
671		.name		= "mt6577-uart",
672		.pm		= &mtk8250_pm_ops,
673		.of_match_table	= mtk8250_of_match,
674	},
675	.probe			= mtk8250_probe,
676	.remove			= mtk8250_remove,
677};
678module_platform_driver(mtk8250_platform_driver);
679
680#ifdef CONFIG_SERIAL_8250_CONSOLE
681static int __init early_mtk8250_setup(struct earlycon_device *device,
682					const char *options)
683{
684	if (!device->port.membase)
685		return -ENODEV;
686
687	device->port.iotype = UPIO_MEM32;
688	device->port.regshift = 2;
689
690	return early_serial8250_setup(device, NULL);
691}
692
693OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
694#endif
695
696MODULE_AUTHOR("Matthias Brugger");
697MODULE_LICENSE("GPL");
698MODULE_DESCRIPTION("Mediatek 8250 serial port driver");
699