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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * RDA8810PL serial device driver
  4 *
  5 * Copyright RDA Microelectronics Company Limited
  6 * Copyright (c) 2017 Andreas Färber
  7 * Copyright (c) 2018 Manivannan Sadhasivam
  8 */
  9
 10#include <linux/clk.h>
 11#include <linux/console.h>
 12#include <linux/delay.h>
 13#include <linux/io.h>
 14#include <linux/module.h>
 15#include <linux/of.h>
 16#include <linux/platform_device.h>
 17#include <linux/serial.h>
 18#include <linux/serial_core.h>
 19#include <linux/tty.h>
 20#include <linux/tty_flip.h>
 21
 22#define RDA_UART_PORT_NUM 3
 23#define RDA_UART_DEV_NAME "ttyRDA"
 24
 25#define RDA_UART_CTRL		0x00
 26#define RDA_UART_STATUS		0x04
 27#define RDA_UART_RXTX_BUFFER	0x08
 28#define RDA_UART_IRQ_MASK	0x0c
 29#define RDA_UART_IRQ_CAUSE	0x10
 30#define RDA_UART_IRQ_TRIGGERS	0x14
 31#define RDA_UART_CMD_SET	0x18
 32#define RDA_UART_CMD_CLR	0x1c
 33
 34/* UART_CTRL Bits */
 35#define RDA_UART_ENABLE			BIT(0)
 36#define RDA_UART_DBITS_8		BIT(1)
 37#define RDA_UART_TX_SBITS_2		BIT(2)
 38#define RDA_UART_PARITY_EN		BIT(3)
 39#define RDA_UART_PARITY(x)		(((x) & 0x3) << 4)
 40#define RDA_UART_PARITY_ODD		RDA_UART_PARITY(0)
 41#define RDA_UART_PARITY_EVEN		RDA_UART_PARITY(1)
 42#define RDA_UART_PARITY_SPACE		RDA_UART_PARITY(2)
 43#define RDA_UART_PARITY_MARK		RDA_UART_PARITY(3)
 44#define RDA_UART_DIV_MODE		BIT(20)
 45#define RDA_UART_IRDA_EN		BIT(21)
 46#define RDA_UART_DMA_EN			BIT(22)
 47#define RDA_UART_FLOW_CNT_EN		BIT(23)
 48#define RDA_UART_LOOP_BACK_EN		BIT(24)
 49#define RDA_UART_RX_LOCK_ERR		BIT(25)
 50#define RDA_UART_RX_BREAK_LEN(x)	(((x) & 0xf) << 28)
 51
 52/* UART_STATUS Bits */
 53#define RDA_UART_RX_FIFO(x)		(((x) & 0x7f) << 0)
 54#define RDA_UART_RX_FIFO_MASK		(0x7f << 0)
 55#define RDA_UART_TX_FIFO(x)		(((x) & 0x1f) << 8)
 56#define RDA_UART_TX_FIFO_MASK		(0x1f << 8)
 57#define RDA_UART_TX_ACTIVE		BIT(14)
 58#define RDA_UART_RX_ACTIVE		BIT(15)
 59#define RDA_UART_RX_OVERFLOW_ERR	BIT(16)
 60#define RDA_UART_TX_OVERFLOW_ERR	BIT(17)
 61#define RDA_UART_RX_PARITY_ERR		BIT(18)
 62#define RDA_UART_RX_FRAMING_ERR		BIT(19)
 63#define RDA_UART_RX_BREAK_INT		BIT(20)
 64#define RDA_UART_DCTS			BIT(24)
 65#define RDA_UART_CTS			BIT(25)
 66#define RDA_UART_DTR			BIT(28)
 67#define RDA_UART_CLK_ENABLED		BIT(31)
 68
 69/* UART_RXTX_BUFFER Bits */
 70#define RDA_UART_RX_DATA(x)		(((x) & 0xff) << 0)
 71#define RDA_UART_TX_DATA(x)		(((x) & 0xff) << 0)
 72
 73/* UART_IRQ_MASK Bits */
 74#define RDA_UART_TX_MODEM_STATUS	BIT(0)
 75#define RDA_UART_RX_DATA_AVAILABLE	BIT(1)
 76#define RDA_UART_TX_DATA_NEEDED		BIT(2)
 77#define RDA_UART_RX_TIMEOUT		BIT(3)
 78#define RDA_UART_RX_LINE_ERR		BIT(4)
 79#define RDA_UART_TX_DMA_DONE		BIT(5)
 80#define RDA_UART_RX_DMA_DONE		BIT(6)
 81#define RDA_UART_RX_DMA_TIMEOUT		BIT(7)
 82#define RDA_UART_DTR_RISE		BIT(8)
 83#define RDA_UART_DTR_FALL		BIT(9)
 84
 85/* UART_IRQ_CAUSE Bits */
 86#define RDA_UART_TX_MODEM_STATUS_U	BIT(16)
 87#define RDA_UART_RX_DATA_AVAILABLE_U	BIT(17)
 88#define RDA_UART_TX_DATA_NEEDED_U	BIT(18)
 89#define RDA_UART_RX_TIMEOUT_U		BIT(19)
 90#define RDA_UART_RX_LINE_ERR_U		BIT(20)
 91#define RDA_UART_TX_DMA_DONE_U		BIT(21)
 92#define RDA_UART_RX_DMA_DONE_U		BIT(22)
 93#define RDA_UART_RX_DMA_TIMEOUT_U	BIT(23)
 94#define RDA_UART_DTR_RISE_U		BIT(24)
 95#define RDA_UART_DTR_FALL_U		BIT(25)
 96
 97/* UART_TRIGGERS Bits */
 98#define RDA_UART_RX_TRIGGER(x)		(((x) & 0x1f) << 0)
 99#define RDA_UART_TX_TRIGGER(x)		(((x) & 0xf) << 8)
100#define RDA_UART_AFC_LEVEL(x)		(((x) & 0x1f) << 16)
101
102/* UART_CMD_SET Bits */
103#define RDA_UART_RI			BIT(0)
104#define RDA_UART_DCD			BIT(1)
105#define RDA_UART_DSR			BIT(2)
106#define RDA_UART_TX_BREAK_CONTROL	BIT(3)
107#define RDA_UART_TX_FINISH_N_WAIT	BIT(4)
108#define RDA_UART_RTS			BIT(5)
109#define RDA_UART_RX_FIFO_RESET		BIT(6)
110#define RDA_UART_TX_FIFO_RESET		BIT(7)
111
112#define RDA_UART_TX_FIFO_SIZE	16
113
114static struct uart_driver rda_uart_driver;
115
116struct rda_uart_port {
117	struct uart_port port;
118	struct clk *clk;
119};
120
121#define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
122
123static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
124
125static inline void rda_uart_write(struct uart_port *port, u32 val,
126				  unsigned int off)
127{
128	writel(val, port->membase + off);
129}
130
131static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
132{
133	return readl(port->membase + off);
134}
135
136static unsigned int rda_uart_tx_empty(struct uart_port *port)
137{
138	unsigned long flags;
139	unsigned int ret;
140	u32 val;
141
142	uart_port_lock_irqsave(port, &flags);
143
144	val = rda_uart_read(port, RDA_UART_STATUS);
145	ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
146
147	uart_port_unlock_irqrestore(port, flags);
148
149	return ret;
150}
151
152static unsigned int rda_uart_get_mctrl(struct uart_port *port)
153{
154	unsigned int mctrl = 0;
155	u32 cmd_set, status;
156
157	cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
158	status = rda_uart_read(port, RDA_UART_STATUS);
159	if (cmd_set & RDA_UART_RTS)
160		mctrl |= TIOCM_RTS;
161	if (!(status & RDA_UART_CTS))
162		mctrl |= TIOCM_CTS;
163
164	return mctrl;
165}
166
167static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
168{
169	u32 val;
170
171	if (mctrl & TIOCM_RTS) {
172		val = rda_uart_read(port, RDA_UART_CMD_SET);
173		rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
174	} else {
175		/* Clear RTS to stop to receive. */
176		val = rda_uart_read(port, RDA_UART_CMD_CLR);
177		rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
178	}
179
180	val = rda_uart_read(port, RDA_UART_CTRL);
181
182	if (mctrl & TIOCM_LOOP)
183		val |= RDA_UART_LOOP_BACK_EN;
184	else
185		val &= ~RDA_UART_LOOP_BACK_EN;
186
187	rda_uart_write(port, val, RDA_UART_CTRL);
188}
189
190static void rda_uart_stop_tx(struct uart_port *port)
191{
192	u32 val;
193
194	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
195	val &= ~RDA_UART_TX_DATA_NEEDED;
196	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
197
198	val = rda_uart_read(port, RDA_UART_CMD_SET);
199	val |= RDA_UART_TX_FIFO_RESET;
200	rda_uart_write(port, val, RDA_UART_CMD_SET);
201}
202
203static void rda_uart_stop_rx(struct uart_port *port)
204{
205	u32 val;
206
207	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
208	val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
209	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
210
211	/* Read Rx buffer before reset to avoid Rx timeout interrupt */
212	val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
213
214	val = rda_uart_read(port, RDA_UART_CMD_SET);
215	val |= RDA_UART_RX_FIFO_RESET;
216	rda_uart_write(port, val, RDA_UART_CMD_SET);
217}
218
219static void rda_uart_start_tx(struct uart_port *port)
220{
221	u32 val;
222
223	if (uart_tx_stopped(port)) {
224		rda_uart_stop_tx(port);
225		return;
226	}
227
228	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
229	val |= RDA_UART_TX_DATA_NEEDED;
230	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
231}
232
233static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
234				     unsigned long baud)
235{
236	clk_set_rate(rda_port->clk, baud * 8);
237}
238
239static void rda_uart_set_termios(struct uart_port *port,
240				 struct ktermios *termios,
241				 const struct ktermios *old)
242{
243	struct rda_uart_port *rda_port = to_rda_uart_port(port);
244	unsigned long flags;
245	unsigned int ctrl, cmd_set, cmd_clr, triggers;
246	unsigned int baud;
247	u32 irq_mask;
248
249	uart_port_lock_irqsave(port, &flags);
250
251	baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
252	rda_uart_change_baudrate(rda_port, baud);
253
254	ctrl = rda_uart_read(port, RDA_UART_CTRL);
255	cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
256	cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
257
258	switch (termios->c_cflag & CSIZE) {
259	case CS5:
260	case CS6:
261		dev_warn(port->dev, "bit size not supported, using 7 bits\n");
262		fallthrough;
263	case CS7:
264		ctrl &= ~RDA_UART_DBITS_8;
265		termios->c_cflag &= ~CSIZE;
266		termios->c_cflag |= CS7;
267		break;
268	default:
269		ctrl |= RDA_UART_DBITS_8;
270		break;
271	}
272
273	/* stop bits */
274	if (termios->c_cflag & CSTOPB)
275		ctrl |= RDA_UART_TX_SBITS_2;
276	else
277		ctrl &= ~RDA_UART_TX_SBITS_2;
278
279	/* parity check */
280	if (termios->c_cflag & PARENB) {
281		ctrl |= RDA_UART_PARITY_EN;
282
283		/* Mark or Space parity */
284		if (termios->c_cflag & CMSPAR) {
285			if (termios->c_cflag & PARODD)
286				ctrl |= RDA_UART_PARITY_MARK;
287			else
288				ctrl |= RDA_UART_PARITY_SPACE;
289		} else if (termios->c_cflag & PARODD) {
290			ctrl |= RDA_UART_PARITY_ODD;
291		} else {
292			ctrl |= RDA_UART_PARITY_EVEN;
293		}
294	} else {
295		ctrl &= ~RDA_UART_PARITY_EN;
296	}
297
298	/* Hardware handshake (RTS/CTS) */
299	if (termios->c_cflag & CRTSCTS) {
300		ctrl   |= RDA_UART_FLOW_CNT_EN;
301		cmd_set |= RDA_UART_RTS;
302	} else {
303		ctrl   &= ~RDA_UART_FLOW_CNT_EN;
304		cmd_clr |= RDA_UART_RTS;
305	}
306
307	ctrl |= RDA_UART_ENABLE;
308	ctrl &= ~RDA_UART_DMA_EN;
309
310	triggers  = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
311	irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
312	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
313
314	rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
315	rda_uart_write(port, ctrl, RDA_UART_CTRL);
316	rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
317	rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
318
319	rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
320
321	/* Don't rewrite B0 */
322	if (tty_termios_baud_rate(termios))
323		tty_termios_encode_baud_rate(termios, baud, baud);
324
325	/* update the per-port timeout */
326	uart_update_timeout(port, termios->c_cflag, baud);
327
328	uart_port_unlock_irqrestore(port, flags);
329}
330
331static void rda_uart_send_chars(struct uart_port *port)
332{
333	struct tty_port *tport = &port->state->port;
334	unsigned char ch;
335	u32 val;
336
337	if (uart_tx_stopped(port))
338		return;
339
340	if (port->x_char) {
341		while (!(rda_uart_read(port, RDA_UART_STATUS) &
342			 RDA_UART_TX_FIFO_MASK))
343			cpu_relax();
344
345		rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
346		port->icount.tx++;
347		port->x_char = 0;
348	}
349
350	while ((rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) &&
351			uart_fifo_get(port, &ch))
352		rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
353
354	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
355		uart_write_wakeup(port);
356
357	if (!kfifo_is_empty(&tport->xmit_fifo)) {
358		/* Re-enable Tx FIFO interrupt */
359		val = rda_uart_read(port, RDA_UART_IRQ_MASK);
360		val |= RDA_UART_TX_DATA_NEEDED;
361		rda_uart_write(port, val, RDA_UART_IRQ_MASK);
362	}
363}
364
365static void rda_uart_receive_chars(struct uart_port *port)
366{
367	u32 status, val;
368
369	status = rda_uart_read(port, RDA_UART_STATUS);
370	while ((status & RDA_UART_RX_FIFO_MASK)) {
371		char flag = TTY_NORMAL;
372
373		if (status & RDA_UART_RX_PARITY_ERR) {
374			port->icount.parity++;
375			flag = TTY_PARITY;
376		}
377
378		if (status & RDA_UART_RX_FRAMING_ERR) {
379			port->icount.frame++;
380			flag = TTY_FRAME;
381		}
382
383		if (status & RDA_UART_RX_OVERFLOW_ERR) {
384			port->icount.overrun++;
385			flag = TTY_OVERRUN;
386		}
387
388		val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
389		val &= 0xff;
390
391		port->icount.rx++;
392		if (!uart_prepare_sysrq_char(port, val))
393			tty_insert_flip_char(&port->state->port, val, flag);
394
395		status = rda_uart_read(port, RDA_UART_STATUS);
396	}
397
398	tty_flip_buffer_push(&port->state->port);
399}
400
401static irqreturn_t rda_interrupt(int irq, void *dev_id)
402{
403	struct uart_port *port = dev_id;
404	u32 val, irq_mask;
405
406	uart_port_lock(port);
407
408	/* Clear IRQ cause */
409	val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
410	rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
411
412	if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
413		rda_uart_receive_chars(port);
414
415	if (val & (RDA_UART_TX_DATA_NEEDED)) {
416		irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
417		irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
418		rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
419
420		rda_uart_send_chars(port);
421	}
422
423	uart_unlock_and_check_sysrq(port);
424
425	return IRQ_HANDLED;
426}
427
428static int rda_uart_startup(struct uart_port *port)
429{
430	unsigned long flags;
431	int ret;
432	u32 val;
433
434	uart_port_lock_irqsave(port, &flags);
435	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
436	uart_port_unlock_irqrestore(port, flags);
437
438	ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
439			  "rda-uart", port);
440	if (ret)
441		return ret;
442
443	uart_port_lock_irqsave(port, &flags);
444
445	val = rda_uart_read(port, RDA_UART_CTRL);
446	val |= RDA_UART_ENABLE;
447	rda_uart_write(port, val, RDA_UART_CTRL);
448
449	/* enable rx interrupt */
450	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
451	val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
452	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
453
454	uart_port_unlock_irqrestore(port, flags);
455
456	return 0;
457}
458
459static void rda_uart_shutdown(struct uart_port *port)
460{
461	unsigned long flags;
462	u32 val;
463
464	uart_port_lock_irqsave(port, &flags);
465
466	rda_uart_stop_tx(port);
467	rda_uart_stop_rx(port);
468
469	val = rda_uart_read(port, RDA_UART_CTRL);
470	val &= ~RDA_UART_ENABLE;
471	rda_uart_write(port, val, RDA_UART_CTRL);
472
473	uart_port_unlock_irqrestore(port, flags);
474}
475
476static const char *rda_uart_type(struct uart_port *port)
477{
478	return (port->type == PORT_RDA) ? "rda-uart" : NULL;
479}
480
481static int rda_uart_request_port(struct uart_port *port)
482{
483	struct platform_device *pdev = to_platform_device(port->dev);
484	struct resource *res;
485
486	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
487	if (!res)
488		return -ENXIO;
489
490	if (!devm_request_mem_region(port->dev, port->mapbase,
491				     resource_size(res), dev_name(port->dev)))
492		return -EBUSY;
493
494	if (port->flags & UPF_IOREMAP) {
495		port->membase = devm_ioremap(port->dev, port->mapbase,
496						     resource_size(res));
497		if (!port->membase)
498			return -EBUSY;
499	}
500
501	return 0;
502}
503
504static void rda_uart_config_port(struct uart_port *port, int flags)
505{
506	unsigned long irq_flags;
507
508	if (flags & UART_CONFIG_TYPE) {
509		port->type = PORT_RDA;
510		rda_uart_request_port(port);
511	}
512
513	uart_port_lock_irqsave(port, &irq_flags);
514
515	/* Clear mask, so no surprise interrupts. */
516	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
517
518	/* Clear status register */
519	rda_uart_write(port, 0, RDA_UART_STATUS);
520
521	uart_port_unlock_irqrestore(port, irq_flags);
522}
523
524static void rda_uart_release_port(struct uart_port *port)
525{
526	struct platform_device *pdev = to_platform_device(port->dev);
527	struct resource *res;
528
529	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
530	if (!res)
531		return;
532
533	if (port->flags & UPF_IOREMAP) {
534		devm_release_mem_region(port->dev, port->mapbase,
535					resource_size(res));
536		devm_iounmap(port->dev, port->membase);
537		port->membase = NULL;
538	}
539}
540
541static int rda_uart_verify_port(struct uart_port *port,
542				struct serial_struct *ser)
543{
544	if (port->type != PORT_RDA)
545		return -EINVAL;
546
547	if (port->irq != ser->irq)
548		return -EINVAL;
549
550	return 0;
551}
552
553static const struct uart_ops rda_uart_ops = {
554	.tx_empty       = rda_uart_tx_empty,
555	.get_mctrl      = rda_uart_get_mctrl,
556	.set_mctrl      = rda_uart_set_mctrl,
557	.start_tx       = rda_uart_start_tx,
558	.stop_tx        = rda_uart_stop_tx,
559	.stop_rx        = rda_uart_stop_rx,
560	.startup        = rda_uart_startup,
561	.shutdown       = rda_uart_shutdown,
562	.set_termios    = rda_uart_set_termios,
563	.type           = rda_uart_type,
564	.request_port	= rda_uart_request_port,
565	.release_port	= rda_uart_release_port,
566	.config_port	= rda_uart_config_port,
567	.verify_port	= rda_uart_verify_port,
568};
569
570#ifdef CONFIG_SERIAL_RDA_CONSOLE
571
572static void rda_console_putchar(struct uart_port *port, unsigned char ch)
573{
574	if (!port->membase)
575		return;
576
577	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
578		cpu_relax();
579
580	rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
581}
582
583static void rda_uart_port_write(struct uart_port *port, const char *s,
584				u_int count)
585{
586	u32 old_irq_mask;
587	unsigned long flags;
588	int locked = 1;
589
590	if (oops_in_progress)
591		locked = uart_port_trylock_irqsave(port, &flags);
592	else
593		uart_port_lock_irqsave(port, &flags);
594
595	old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
596	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
597
598	uart_console_write(port, s, count, rda_console_putchar);
599
600	/* wait until all contents have been sent out */
601	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
602		cpu_relax();
603
604	rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
605
606	if (locked)
607		uart_port_unlock_irqrestore(port, flags);
608}
609
610static void rda_uart_console_write(struct console *co, const char *s,
611				   u_int count)
612{
613	struct rda_uart_port *rda_port;
614
615	rda_port = rda_uart_ports[co->index];
616	if (!rda_port)
617		return;
618
619	rda_uart_port_write(&rda_port->port, s, count);
620}
621
622static int rda_uart_console_setup(struct console *co, char *options)
623{
624	struct rda_uart_port *rda_port;
625	int baud = 921600;
626	int bits = 8;
627	int parity = 'n';
628	int flow = 'n';
629
630	if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
631		return -EINVAL;
632
633	rda_port = rda_uart_ports[co->index];
634	if (!rda_port || !rda_port->port.membase)
635		return -ENODEV;
636
637	if (options)
638		uart_parse_options(options, &baud, &parity, &bits, &flow);
639
640	return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
641}
642
643static struct console rda_uart_console = {
644	.name = RDA_UART_DEV_NAME,
645	.write = rda_uart_console_write,
646	.device = uart_console_device,
647	.setup = rda_uart_console_setup,
648	.flags = CON_PRINTBUFFER,
649	.index = -1,
650	.data = &rda_uart_driver,
651};
652
653static int __init rda_uart_console_init(void)
654{
655	register_console(&rda_uart_console);
656
657	return 0;
658}
659console_initcall(rda_uart_console_init);
660
661static void rda_uart_early_console_write(struct console *co,
662					 const char *s,
663					 u_int count)
664{
665	struct earlycon_device *dev = co->data;
666
667	rda_uart_port_write(&dev->port, s, count);
668}
669
670static int __init
671rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
672{
673	if (!device->port.membase)
674		return -ENODEV;
675
676	device->con->write = rda_uart_early_console_write;
677
678	return 0;
679}
680
681OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
682		    rda_uart_early_console_setup);
683
684#define RDA_UART_CONSOLE (&rda_uart_console)
685#else
686#define RDA_UART_CONSOLE NULL
687#endif /* CONFIG_SERIAL_RDA_CONSOLE */
688
689static struct uart_driver rda_uart_driver = {
690	.owner = THIS_MODULE,
691	.driver_name = "rda-uart",
692	.dev_name = RDA_UART_DEV_NAME,
693	.nr = RDA_UART_PORT_NUM,
694	.cons = RDA_UART_CONSOLE,
695};
696
697static const struct of_device_id rda_uart_dt_matches[] = {
698	{ .compatible = "rda,8810pl-uart" },
699	{ }
700};
701MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
702
703static int rda_uart_probe(struct platform_device *pdev)
704{
705	struct resource *res_mem;
706	struct rda_uart_port *rda_port;
707	int ret, irq;
708
709	if (pdev->dev.of_node)
710		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
711
712	if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
713		dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
714		return -EINVAL;
715	}
716
717	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
718	if (!res_mem) {
719		dev_err(&pdev->dev, "could not get mem\n");
720		return -ENODEV;
721	}
722
723	irq = platform_get_irq(pdev, 0);
724	if (irq < 0)
725		return irq;
726
727	if (rda_uart_ports[pdev->id]) {
728		dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
729		return -EBUSY;
730	}
731
732	rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
733	if (!rda_port)
734		return -ENOMEM;
735
736	rda_port->clk = devm_clk_get(&pdev->dev, NULL);
737	if (IS_ERR(rda_port->clk)) {
738		dev_err(&pdev->dev, "could not get clk\n");
739		return PTR_ERR(rda_port->clk);
740	}
741
742	rda_port->port.dev = &pdev->dev;
743	rda_port->port.regshift = 0;
744	rda_port->port.line = pdev->id;
745	rda_port->port.type = PORT_RDA;
746	rda_port->port.iotype = UPIO_MEM;
747	rda_port->port.mapbase = res_mem->start;
748	rda_port->port.irq = irq;
749	rda_port->port.uartclk = clk_get_rate(rda_port->clk);
750	if (rda_port->port.uartclk == 0) {
751		dev_err(&pdev->dev, "clock rate is zero\n");
752		return -EINVAL;
753	}
754	rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
755			       UPF_LOW_LATENCY;
756	rda_port->port.x_char = 0;
757	rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
758	rda_port->port.ops = &rda_uart_ops;
759
760	rda_uart_ports[pdev->id] = rda_port;
761	platform_set_drvdata(pdev, rda_port);
762
763	ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
764	if (ret)
765		rda_uart_ports[pdev->id] = NULL;
766
767	return ret;
768}
769
770static void rda_uart_remove(struct platform_device *pdev)
771{
772	struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
773
774	uart_remove_one_port(&rda_uart_driver, &rda_port->port);
775	rda_uart_ports[pdev->id] = NULL;
776}
777
778static struct platform_driver rda_uart_platform_driver = {
779	.probe = rda_uart_probe,
780	.remove = rda_uart_remove,
781	.driver = {
782		.name = "rda-uart",
783		.of_match_table = rda_uart_dt_matches,
784	},
785};
786
787static int __init rda_uart_init(void)
788{
789	int ret;
790
791	ret = uart_register_driver(&rda_uart_driver);
792	if (ret)
793		return ret;
794
795	ret = platform_driver_register(&rda_uart_platform_driver);
796	if (ret)
797		uart_unregister_driver(&rda_uart_driver);
798
799	return ret;
800}
801
802static void __exit rda_uart_exit(void)
803{
804	platform_driver_unregister(&rda_uart_platform_driver);
805	uart_unregister_driver(&rda_uart_driver);
806}
807
808module_init(rda_uart_init);
809module_exit(rda_uart_exit);
810
811MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
812MODULE_DESCRIPTION("RDA8810PL serial device driver");
813MODULE_LICENSE("GPL");