1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Actions Semi Owl family serial console
4 *
5 * Copyright 2013 Actions Semi Inc.
6 * Author: Actions Semi, Inc.
7 *
8 * Copyright (c) 2016-2017 Andreas F��rber
9 */
10
11#include <linux/clk.h>
12#include <linux/console.h>
13#include <linux/delay.h>
14#include <linux/io.h>
15#include <linux/iopoll.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/serial.h>
20#include <linux/serial_core.h>
21#include <linux/tty.h>
22#include <linux/tty_flip.h>
23
24#define OWL_UART_PORT_NUM 7
25#define OWL_UART_DEV_NAME "ttyOWL"
26
27#define OWL_UART_CTL	0x000
28#define OWL_UART_RXDAT	0x004
29#define OWL_UART_TXDAT	0x008
30#define OWL_UART_STAT	0x00c
31
32#define OWL_UART_CTL_DWLS_MASK		GENMASK(1, 0)
33#define OWL_UART_CTL_DWLS_5BITS		(0x0 << 0)
34#define OWL_UART_CTL_DWLS_6BITS		(0x1 << 0)
35#define OWL_UART_CTL_DWLS_7BITS		(0x2 << 0)
36#define OWL_UART_CTL_DWLS_8BITS		(0x3 << 0)
37#define OWL_UART_CTL_STPS_2BITS		BIT(2)
38#define OWL_UART_CTL_PRS_MASK		GENMASK(6, 4)
39#define OWL_UART_CTL_PRS_NONE		(0x0 << 4)
40#define OWL_UART_CTL_PRS_ODD		(0x4 << 4)
41#define OWL_UART_CTL_PRS_MARK		(0x5 << 4)
42#define OWL_UART_CTL_PRS_EVEN		(0x6 << 4)
43#define OWL_UART_CTL_PRS_SPACE		(0x7 << 4)
44#define OWL_UART_CTL_AFE		BIT(12)
45#define OWL_UART_CTL_TRFS_TX		BIT(14)
46#define OWL_UART_CTL_EN			BIT(15)
47#define OWL_UART_CTL_RXDE		BIT(16)
48#define OWL_UART_CTL_TXDE		BIT(17)
49#define OWL_UART_CTL_RXIE		BIT(18)
50#define OWL_UART_CTL_TXIE		BIT(19)
51#define OWL_UART_CTL_LBEN		BIT(20)
52
53#define OWL_UART_STAT_RIP		BIT(0)
54#define OWL_UART_STAT_TIP		BIT(1)
55#define OWL_UART_STAT_RXER		BIT(2)
56#define OWL_UART_STAT_TFER		BIT(3)
57#define OWL_UART_STAT_RXST		BIT(4)
58#define OWL_UART_STAT_RFEM		BIT(5)
59#define OWL_UART_STAT_TFFU		BIT(6)
60#define OWL_UART_STAT_CTSS		BIT(7)
61#define OWL_UART_STAT_RTSS		BIT(8)
62#define OWL_UART_STAT_TFES		BIT(10)
63#define OWL_UART_STAT_TRFL_MASK		GENMASK(16, 11)
64#define OWL_UART_STAT_UTBB		BIT(17)
65
66#define OWL_UART_POLL_USEC		5
67#define OWL_UART_TIMEOUT_USEC		10000
68
69static struct uart_driver owl_uart_driver;
70
71struct owl_uart_info {
72	unsigned int tx_fifosize;
73};
74
75struct owl_uart_port {
76	struct uart_port port;
77	struct clk *clk;
78};
79
80#define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt)
81
82static struct owl_uart_port *owl_uart_ports[OWL_UART_PORT_NUM];
83
84static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off)
85{
86	writel(val, port->membase + off);
87}
88
89static inline u32 owl_uart_read(struct uart_port *port, unsigned int off)
90{
91	return readl(port->membase + off);
92}
93
94static void owl_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
95{
96	u32 ctl;
97
98	ctl = owl_uart_read(port, OWL_UART_CTL);
99
100	if (mctrl & TIOCM_LOOP)
101		ctl |= OWL_UART_CTL_LBEN;
102	else
103		ctl &= ~OWL_UART_CTL_LBEN;
104
105	owl_uart_write(port, ctl, OWL_UART_CTL);
106}
107
108static unsigned int owl_uart_get_mctrl(struct uart_port *port)
109{
110	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
111	u32 stat, ctl;
112
113	ctl = owl_uart_read(port, OWL_UART_CTL);
114	stat = owl_uart_read(port, OWL_UART_STAT);
115	if (stat & OWL_UART_STAT_RTSS)
116		mctrl |= TIOCM_RTS;
117	if ((stat & OWL_UART_STAT_CTSS) || !(ctl & OWL_UART_CTL_AFE))
118		mctrl |= TIOCM_CTS;
119	return mctrl;
120}
121
122static unsigned int owl_uart_tx_empty(struct uart_port *port)
123{
124	unsigned long flags;
125	u32 val;
126	unsigned int ret;
127
128	uart_port_lock_irqsave(port, &flags);
129
130	val = owl_uart_read(port, OWL_UART_STAT);
131	ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0;
132
133	uart_port_unlock_irqrestore(port, flags);
134
135	return ret;
136}
137
138static void owl_uart_stop_rx(struct uart_port *port)
139{
140	u32 val;
141
142	val = owl_uart_read(port, OWL_UART_CTL);
143	val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_RXDE);
144	owl_uart_write(port, val, OWL_UART_CTL);
145
146	val = owl_uart_read(port, OWL_UART_STAT);
147	val |= OWL_UART_STAT_RIP;
148	owl_uart_write(port, val, OWL_UART_STAT);
149}
150
151static void owl_uart_stop_tx(struct uart_port *port)
152{
153	u32 val;
154
155	val = owl_uart_read(port, OWL_UART_CTL);
156	val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE);
157	owl_uart_write(port, val, OWL_UART_CTL);
158
159	val = owl_uart_read(port, OWL_UART_STAT);
160	val |= OWL_UART_STAT_TIP;
161	owl_uart_write(port, val, OWL_UART_STAT);
162}
163
164static void owl_uart_start_tx(struct uart_port *port)
165{
166	u32 val;
167
168	if (uart_tx_stopped(port)) {
169		owl_uart_stop_tx(port);
170		return;
171	}
172
173	val = owl_uart_read(port, OWL_UART_STAT);
174	val |= OWL_UART_STAT_TIP;
175	owl_uart_write(port, val, OWL_UART_STAT);
176
177	val = owl_uart_read(port, OWL_UART_CTL);
178	val |= OWL_UART_CTL_TXIE;
179	owl_uart_write(port, val, OWL_UART_CTL);
180}
181
182static void owl_uart_send_chars(struct uart_port *port)
183{
184	u8 ch;
185
186	uart_port_tx(port, ch,
187		!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU),
188		owl_uart_write(port, ch, OWL_UART_TXDAT));
189}
190
191static void owl_uart_receive_chars(struct uart_port *port)
192{
193	u32 stat, val;
194
195	val = owl_uart_read(port, OWL_UART_CTL);
196	val &= ~OWL_UART_CTL_TRFS_TX;
197	owl_uart_write(port, val, OWL_UART_CTL);
198
199	stat = owl_uart_read(port, OWL_UART_STAT);
200	while (!(stat & OWL_UART_STAT_RFEM)) {
201		char flag = TTY_NORMAL;
202		bool sysrq;
203
204		if (stat & OWL_UART_STAT_RXER)
205			port->icount.overrun++;
206
207		if (stat & OWL_UART_STAT_RXST) {
208			/* We are not able to distinguish the error type. */
209			port->icount.brk++;
210			port->icount.frame++;
211
212			stat &= port->read_status_mask;
213			if (stat & OWL_UART_STAT_RXST)
214				flag = TTY_PARITY;
215		} else
216			port->icount.rx++;
217
218		val = owl_uart_read(port, OWL_UART_RXDAT);
219		val &= 0xff;
220
221		sysrq = uart_prepare_sysrq_char(port, val);
222
223		if (!sysrq && (stat & port->ignore_status_mask) == 0)
224			tty_insert_flip_char(&port->state->port, val, flag);
225
226		stat = owl_uart_read(port, OWL_UART_STAT);
227	}
228
229	tty_flip_buffer_push(&port->state->port);
230}
231
232static irqreturn_t owl_uart_irq(int irq, void *dev_id)
233{
234	struct uart_port *port = dev_id;
235	u32 stat;
236
237	uart_port_lock(port);
238
239	stat = owl_uart_read(port, OWL_UART_STAT);
240
241	if (stat & OWL_UART_STAT_RIP)
242		owl_uart_receive_chars(port);
243
244	if (stat & OWL_UART_STAT_TIP)
245		owl_uart_send_chars(port);
246
247	stat = owl_uart_read(port, OWL_UART_STAT);
248	stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP;
249	owl_uart_write(port, stat, OWL_UART_STAT);
250
251	uart_unlock_and_check_sysrq(port);
252
253	return IRQ_HANDLED;
254}
255
256static void owl_uart_shutdown(struct uart_port *port)
257{
258	u32 val;
259	unsigned long flags;
260
261	uart_port_lock_irqsave(port, &flags);
262
263	val = owl_uart_read(port, OWL_UART_CTL);
264	val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
265		| OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN);
266	owl_uart_write(port, val, OWL_UART_CTL);
267
268	uart_port_unlock_irqrestore(port, flags);
269
270	free_irq(port->irq, port);
271}
272
273static int owl_uart_startup(struct uart_port *port)
274{
275	u32 val;
276	unsigned long flags;
277	int ret;
278
279	ret = request_irq(port->irq, owl_uart_irq, IRQF_TRIGGER_HIGH,
280			"owl-uart", port);
281	if (ret)
282		return ret;
283
284	uart_port_lock_irqsave(port, &flags);
285
286	val = owl_uart_read(port, OWL_UART_STAT);
287	val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP
288		| OWL_UART_STAT_RXER | OWL_UART_STAT_TFER | OWL_UART_STAT_RXST;
289	owl_uart_write(port, val, OWL_UART_STAT);
290
291	val = owl_uart_read(port, OWL_UART_CTL);
292	val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE;
293	val |= OWL_UART_CTL_EN;
294	owl_uart_write(port, val, OWL_UART_CTL);
295
296	uart_port_unlock_irqrestore(port, flags);
297
298	return 0;
299}
300
301static void owl_uart_change_baudrate(struct owl_uart_port *owl_port,
302				     unsigned long baud)
303{
304	clk_set_rate(owl_port->clk, baud * 8);
305}
306
307static void owl_uart_set_termios(struct uart_port *port,
308				 struct ktermios *termios,
309				 const struct ktermios *old)
310{
311	struct owl_uart_port *owl_port = to_owl_uart_port(port);
312	unsigned int baud;
313	u32 ctl;
314	unsigned long flags;
315
316	uart_port_lock_irqsave(port, &flags);
317
318	ctl = owl_uart_read(port, OWL_UART_CTL);
319
320	ctl &= ~OWL_UART_CTL_DWLS_MASK;
321	switch (termios->c_cflag & CSIZE) {
322	case CS5:
323		ctl |= OWL_UART_CTL_DWLS_5BITS;
324		break;
325	case CS6:
326		ctl |= OWL_UART_CTL_DWLS_6BITS;
327		break;
328	case CS7:
329		ctl |= OWL_UART_CTL_DWLS_7BITS;
330		break;
331	case CS8:
332	default:
333		ctl |= OWL_UART_CTL_DWLS_8BITS;
334		break;
335	}
336
337	if (termios->c_cflag & CSTOPB)
338		ctl |= OWL_UART_CTL_STPS_2BITS;
339	else
340		ctl &= ~OWL_UART_CTL_STPS_2BITS;
341
342	ctl &= ~OWL_UART_CTL_PRS_MASK;
343	if (termios->c_cflag & PARENB) {
344		if (termios->c_cflag & CMSPAR) {
345			if (termios->c_cflag & PARODD)
346				ctl |= OWL_UART_CTL_PRS_MARK;
347			else
348				ctl |= OWL_UART_CTL_PRS_SPACE;
349		} else if (termios->c_cflag & PARODD)
350			ctl |= OWL_UART_CTL_PRS_ODD;
351		else
352			ctl |= OWL_UART_CTL_PRS_EVEN;
353	} else
354		ctl |= OWL_UART_CTL_PRS_NONE;
355
356	if (termios->c_cflag & CRTSCTS)
357		ctl |= OWL_UART_CTL_AFE;
358	else
359		ctl &= ~OWL_UART_CTL_AFE;
360
361	owl_uart_write(port, ctl, OWL_UART_CTL);
362
363	baud = uart_get_baud_rate(port, termios, old, 9600, 3200000);
364	owl_uart_change_baudrate(owl_port, baud);
365
366	/* Don't rewrite B0 */
367	if (tty_termios_baud_rate(termios))
368		tty_termios_encode_baud_rate(termios, baud, baud);
369
370	port->read_status_mask |= OWL_UART_STAT_RXER;
371	if (termios->c_iflag & INPCK)
372		port->read_status_mask |= OWL_UART_STAT_RXST;
373
374	uart_update_timeout(port, termios->c_cflag, baud);
375
376	uart_port_unlock_irqrestore(port, flags);
377}
378
379static void owl_uart_release_port(struct uart_port *port)
380{
381	struct platform_device *pdev = to_platform_device(port->dev);
382	struct resource *res;
383
384	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
385	if (!res)
386		return;
387
388	if (port->flags & UPF_IOREMAP) {
389		devm_release_mem_region(port->dev, port->mapbase,
390			resource_size(res));
391		devm_iounmap(port->dev, port->membase);
392		port->membase = NULL;
393	}
394}
395
396static int owl_uart_request_port(struct uart_port *port)
397{
398	struct platform_device *pdev = to_platform_device(port->dev);
399	struct resource *res;
400
401	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
402	if (!res)
403		return -ENXIO;
404
405	if (!devm_request_mem_region(port->dev, port->mapbase,
406			resource_size(res), dev_name(port->dev)))
407		return -EBUSY;
408
409	if (port->flags & UPF_IOREMAP) {
410		port->membase = devm_ioremap(port->dev, port->mapbase,
411				resource_size(res));
412		if (!port->membase)
413			return -EBUSY;
414	}
415
416	return 0;
417}
418
419static const char *owl_uart_type(struct uart_port *port)
420{
421	return (port->type == PORT_OWL) ? "owl-uart" : NULL;
422}
423
424static int owl_uart_verify_port(struct uart_port *port,
425				struct serial_struct *ser)
426{
427	if (port->type != PORT_OWL)
428		return -EINVAL;
429
430	if (port->irq != ser->irq)
431		return -EINVAL;
432
433	return 0;
434}
435
436static void owl_uart_config_port(struct uart_port *port, int flags)
437{
438	if (flags & UART_CONFIG_TYPE) {
439		port->type = PORT_OWL;
440		owl_uart_request_port(port);
441	}
442}
443
444#ifdef CONFIG_CONSOLE_POLL
445
446static int owl_uart_poll_get_char(struct uart_port *port)
447{
448	if (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_RFEM)
449		return NO_POLL_CHAR;
450
451	return owl_uart_read(port, OWL_UART_RXDAT);
452}
453
454static void owl_uart_poll_put_char(struct uart_port *port, unsigned char ch)
455{
456	u32 reg;
457	int ret;
458
459	/* Wait while FIFO is full or timeout */
460	ret = readl_poll_timeout_atomic(port->membase + OWL_UART_STAT, reg,
461					!(reg & OWL_UART_STAT_TFFU),
462					OWL_UART_POLL_USEC,
463					OWL_UART_TIMEOUT_USEC);
464	if (ret == -ETIMEDOUT) {
465		dev_err(port->dev, "Timeout waiting while UART TX FULL\n");
466		return;
467	}
468
469	owl_uart_write(port, ch, OWL_UART_TXDAT);
470}
471
472#endif /* CONFIG_CONSOLE_POLL */
473
474static const struct uart_ops owl_uart_ops = {
475	.set_mctrl = owl_uart_set_mctrl,
476	.get_mctrl = owl_uart_get_mctrl,
477	.tx_empty = owl_uart_tx_empty,
478	.start_tx = owl_uart_start_tx,
479	.stop_rx = owl_uart_stop_rx,
480	.stop_tx = owl_uart_stop_tx,
481	.startup = owl_uart_startup,
482	.shutdown = owl_uart_shutdown,
483	.set_termios = owl_uart_set_termios,
484	.type = owl_uart_type,
485	.config_port = owl_uart_config_port,
486	.request_port = owl_uart_request_port,
487	.release_port = owl_uart_release_port,
488	.verify_port = owl_uart_verify_port,
489#ifdef CONFIG_CONSOLE_POLL
490	.poll_get_char = owl_uart_poll_get_char,
491	.poll_put_char = owl_uart_poll_put_char,
492#endif
493};
494
495#ifdef CONFIG_SERIAL_OWL_CONSOLE
496
497static void owl_console_putchar(struct uart_port *port, unsigned char ch)
498{
499	if (!port->membase)
500		return;
501
502	while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)
503		cpu_relax();
504
505	owl_uart_write(port, ch, OWL_UART_TXDAT);
506}
507
508static void owl_uart_port_write(struct uart_port *port, const char *s,
509				u_int count)
510{
511	u32 old_ctl, val;
512	unsigned long flags;
513	int locked = 1;
514
515	if (oops_in_progress)
516		locked = uart_port_trylock_irqsave(port, &flags);
517	else
518		uart_port_lock_irqsave(port, &flags);
519
520	old_ctl = owl_uart_read(port, OWL_UART_CTL);
521	val = old_ctl | OWL_UART_CTL_TRFS_TX;
522	/* disable IRQ */
523	val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE);
524	owl_uart_write(port, val, OWL_UART_CTL);
525
526	uart_console_write(port, s, count, owl_console_putchar);
527
528	/* wait until all contents have been sent out */
529	while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TRFL_MASK)
530		cpu_relax();
531
532	/* clear IRQ pending */
533	val = owl_uart_read(port, OWL_UART_STAT);
534	val |= OWL_UART_STAT_TIP | OWL_UART_STAT_RIP;
535	owl_uart_write(port, val, OWL_UART_STAT);
536
537	owl_uart_write(port, old_ctl, OWL_UART_CTL);
538
539	if (locked)
540		uart_port_unlock_irqrestore(port, flags);
541}
542
543static void owl_uart_console_write(struct console *co, const char *s,
544				   u_int count)
545{
546	struct owl_uart_port *owl_port;
547
548	owl_port = owl_uart_ports[co->index];
549	if (!owl_port)
550		return;
551
552	owl_uart_port_write(&owl_port->port, s, count);
553}
554
555static int owl_uart_console_setup(struct console *co, char *options)
556{
557	struct owl_uart_port *owl_port;
558	int baud = 115200;
559	int bits = 8;
560	int parity = 'n';
561	int flow = 'n';
562
563	if (co->index < 0 || co->index >= OWL_UART_PORT_NUM)
564		return -EINVAL;
565
566	owl_port = owl_uart_ports[co->index];
567	if (!owl_port || !owl_port->port.membase)
568		return -ENODEV;
569
570	if (options)
571		uart_parse_options(options, &baud, &parity, &bits, &flow);
572
573	return uart_set_options(&owl_port->port, co, baud, parity, bits, flow);
574}
575
576static struct console owl_uart_console = {
577	.name = OWL_UART_DEV_NAME,
578	.write = owl_uart_console_write,
579	.device = uart_console_device,
580	.setup = owl_uart_console_setup,
581	.flags = CON_PRINTBUFFER,
582	.index = -1,
583	.data = &owl_uart_driver,
584};
585
586static int __init owl_uart_console_init(void)
587{
588	register_console(&owl_uart_console);
589
590	return 0;
591}
592console_initcall(owl_uart_console_init);
593
594static void owl_uart_early_console_write(struct console *co,
595					 const char *s,
596					 u_int count)
597{
598	struct earlycon_device *dev = co->data;
599
600	owl_uart_port_write(&dev->port, s, count);
601}
602
603static int __init
604owl_uart_early_console_setup(struct earlycon_device *device, const char *opt)
605{
606	if (!device->port.membase)
607		return -ENODEV;
608
609	device->con->write = owl_uart_early_console_write;
610
611	return 0;
612}
613OF_EARLYCON_DECLARE(owl, "actions,owl-uart",
614		    owl_uart_early_console_setup);
615
616#define OWL_UART_CONSOLE (&owl_uart_console)
617#else
618#define OWL_UART_CONSOLE NULL
619#endif
620
621static struct uart_driver owl_uart_driver = {
622	.owner = THIS_MODULE,
623	.driver_name = "owl-uart",
624	.dev_name = OWL_UART_DEV_NAME,
625	.nr = OWL_UART_PORT_NUM,
626	.cons = OWL_UART_CONSOLE,
627};
628
629static const struct owl_uart_info owl_s500_info = {
630	.tx_fifosize = 16,
631};
632
633static const struct owl_uart_info owl_s900_info = {
634	.tx_fifosize = 32,
635};
636
637static const struct of_device_id owl_uart_dt_matches[] = {
638	{ .compatible = "actions,s500-uart", .data = &owl_s500_info },
639	{ .compatible = "actions,s900-uart", .data = &owl_s900_info },
640	{ }
641};
642MODULE_DEVICE_TABLE(of, owl_uart_dt_matches);
643
644static int owl_uart_probe(struct platform_device *pdev)
645{
646	const struct of_device_id *match;
647	const struct owl_uart_info *info = NULL;
648	struct resource *res_mem;
649	struct owl_uart_port *owl_port;
650	int ret, irq;
651
652	if (pdev->dev.of_node) {
653		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
654		match = of_match_node(owl_uart_dt_matches, pdev->dev.of_node);
655		if (match)
656			info = match->data;
657	}
658
659	if (pdev->id < 0 || pdev->id >= OWL_UART_PORT_NUM) {
660		dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
661		return -EINVAL;
662	}
663
664	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
665	if (!res_mem) {
666		dev_err(&pdev->dev, "could not get mem\n");
667		return -ENODEV;
668	}
669
670	irq = platform_get_irq(pdev, 0);
671	if (irq < 0)
672		return irq;
673
674	if (owl_uart_ports[pdev->id]) {
675		dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
676		return -EBUSY;
677	}
678
679	owl_port = devm_kzalloc(&pdev->dev, sizeof(*owl_port), GFP_KERNEL);
680	if (!owl_port)
681		return -ENOMEM;
682
683	owl_port->clk = devm_clk_get(&pdev->dev, NULL);
684	if (IS_ERR(owl_port->clk)) {
685		dev_err(&pdev->dev, "could not get clk\n");
686		return PTR_ERR(owl_port->clk);
687	}
688
689	ret = clk_prepare_enable(owl_port->clk);
690	if (ret) {
691		dev_err(&pdev->dev, "could not enable clk\n");
692		return ret;
693	}
694
695	owl_port->port.dev = &pdev->dev;
696	owl_port->port.line = pdev->id;
697	owl_port->port.type = PORT_OWL;
698	owl_port->port.iotype = UPIO_MEM;
699	owl_port->port.mapbase = res_mem->start;
700	owl_port->port.irq = irq;
701	owl_port->port.uartclk = clk_get_rate(owl_port->clk);
702	if (owl_port->port.uartclk == 0) {
703		dev_err(&pdev->dev, "clock rate is zero\n");
704		clk_disable_unprepare(owl_port->clk);
705		return -EINVAL;
706	}
707	owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
708	owl_port->port.x_char = 0;
709	owl_port->port.fifosize = (info) ? info->tx_fifosize : 16;
710	owl_port->port.ops = &owl_uart_ops;
711
712	owl_uart_ports[pdev->id] = owl_port;
713	platform_set_drvdata(pdev, owl_port);
714
715	ret = uart_add_one_port(&owl_uart_driver, &owl_port->port);
716	if (ret)
717		owl_uart_ports[pdev->id] = NULL;
718
719	return ret;
720}
721
722static void owl_uart_remove(struct platform_device *pdev)
723{
724	struct owl_uart_port *owl_port = platform_get_drvdata(pdev);
725
726	uart_remove_one_port(&owl_uart_driver, &owl_port->port);
727	owl_uart_ports[pdev->id] = NULL;
728	clk_disable_unprepare(owl_port->clk);
729}
730
731static struct platform_driver owl_uart_platform_driver = {
732	.probe = owl_uart_probe,
733	.remove_new = owl_uart_remove,
734	.driver = {
735		.name = "owl-uart",
736		.of_match_table = owl_uart_dt_matches,
737	},
738};
739
740static int __init owl_uart_init(void)
741{
742	int ret;
743
744	ret = uart_register_driver(&owl_uart_driver);
745	if (ret)
746		return ret;
747
748	ret = platform_driver_register(&owl_uart_platform_driver);
749	if (ret)
750		uart_unregister_driver(&owl_uart_driver);
751
752	return ret;
753}
754
755static void __exit owl_uart_exit(void)
756{
757	platform_driver_unregister(&owl_uart_platform_driver);
758	uart_unregister_driver(&owl_uart_driver);
759}
760
761module_init(owl_uart_init);
762module_exit(owl_uart_exit);
763
764MODULE_LICENSE("GPL");
765