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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	spin_lock_irqsave(&port->lock, flags);
143
144	val = rda_uart_read(port, RDA_UART_STATUS);
145	ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
146
147	spin_unlock_irqrestore(&port->lock, 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				 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	spin_lock_irqsave(&port->lock, 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		/* Fall through */
263	case CS7:
264		ctrl &= ~RDA_UART_DBITS_8;
265		break;
266	default:
267		ctrl |= RDA_UART_DBITS_8;
268		break;
269	}
270
271	/* stop bits */
272	if (termios->c_cflag & CSTOPB)
273		ctrl |= RDA_UART_TX_SBITS_2;
274	else
275		ctrl &= ~RDA_UART_TX_SBITS_2;
276
277	/* parity check */
278	if (termios->c_cflag & PARENB) {
279		ctrl |= RDA_UART_PARITY_EN;
280
281		/* Mark or Space parity */
282		if (termios->c_cflag & CMSPAR) {
283			if (termios->c_cflag & PARODD)
284				ctrl |= RDA_UART_PARITY_MARK;
285			else
286				ctrl |= RDA_UART_PARITY_SPACE;
287		} else if (termios->c_cflag & PARODD) {
288			ctrl |= RDA_UART_PARITY_ODD;
289		} else {
290			ctrl |= RDA_UART_PARITY_EVEN;
291		}
292	} else {
293		ctrl &= ~RDA_UART_PARITY_EN;
294	}
295
296	/* Hardware handshake (RTS/CTS) */
297	if (termios->c_cflag & CRTSCTS) {
298		ctrl   |= RDA_UART_FLOW_CNT_EN;
299		cmd_set |= RDA_UART_RTS;
300	} else {
301		ctrl   &= ~RDA_UART_FLOW_CNT_EN;
302		cmd_clr |= RDA_UART_RTS;
303	}
304
305	ctrl |= RDA_UART_ENABLE;
306	ctrl &= ~RDA_UART_DMA_EN;
307
308	triggers  = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
309	irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
310	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
311
312	rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
313	rda_uart_write(port, ctrl, RDA_UART_CTRL);
314	rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
315	rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
316
317	rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
318
319	/* Don't rewrite B0 */
320	if (tty_termios_baud_rate(termios))
321		tty_termios_encode_baud_rate(termios, baud, baud);
322
323	/* update the per-port timeout */
324	uart_update_timeout(port, termios->c_cflag, baud);
325
326	spin_unlock_irqrestore(&port->lock, flags);
327}
328
329static void rda_uart_send_chars(struct uart_port *port)
330{
331	struct circ_buf *xmit = &port->state->xmit;
332	unsigned int ch;
333	u32 val;
334
335	if (uart_tx_stopped(port))
336		return;
337
338	if (port->x_char) {
339		while (!(rda_uart_read(port, RDA_UART_STATUS) &
340			 RDA_UART_TX_FIFO_MASK))
341			cpu_relax();
342
343		rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
344		port->icount.tx++;
345		port->x_char = 0;
346	}
347
348	while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
349		if (uart_circ_empty(xmit))
350			break;
351
352		ch = xmit->buf[xmit->tail];
353		rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
354		xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
355		port->icount.tx++;
356	}
357
358	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
359		uart_write_wakeup(port);
360
361	if (!uart_circ_empty(xmit)) {
362		/* Re-enable Tx FIFO interrupt */
363		val = rda_uart_read(port, RDA_UART_IRQ_MASK);
364		val |= RDA_UART_TX_DATA_NEEDED;
365		rda_uart_write(port, val, RDA_UART_IRQ_MASK);
366	}
367}
368
369static void rda_uart_receive_chars(struct uart_port *port)
370{
371	u32 status, val;
372
373	status = rda_uart_read(port, RDA_UART_STATUS);
374	while ((status & RDA_UART_RX_FIFO_MASK)) {
375		char flag = TTY_NORMAL;
376
377		if (status & RDA_UART_RX_PARITY_ERR) {
378			port->icount.parity++;
379			flag = TTY_PARITY;
380		}
381
382		if (status & RDA_UART_RX_FRAMING_ERR) {
383			port->icount.frame++;
384			flag = TTY_FRAME;
385		}
386
387		if (status & RDA_UART_RX_OVERFLOW_ERR) {
388			port->icount.overrun++;
389			flag = TTY_OVERRUN;
390		}
391
392		val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
393		val &= 0xff;
394
395		port->icount.rx++;
396		tty_insert_flip_char(&port->state->port, val, flag);
397
398		status = rda_uart_read(port, RDA_UART_STATUS);
399	}
400
401	spin_unlock(&port->lock);
402	tty_flip_buffer_push(&port->state->port);
403	spin_lock(&port->lock);
404}
405
406static irqreturn_t rda_interrupt(int irq, void *dev_id)
407{
408	struct uart_port *port = dev_id;
409	unsigned long flags;
410	u32 val, irq_mask;
411
412	spin_lock_irqsave(&port->lock, flags);
413
414	/* Clear IRQ cause */
415	val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
416	rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
417
418	if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
419		rda_uart_receive_chars(port);
420
421	if (val & (RDA_UART_TX_DATA_NEEDED)) {
422		irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
423		irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
424		rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
425
426		rda_uart_send_chars(port);
427	}
428
429	spin_unlock_irqrestore(&port->lock, flags);
430
431	return IRQ_HANDLED;
432}
433
434static int rda_uart_startup(struct uart_port *port)
435{
436	unsigned long flags;
437	int ret;
438	u32 val;
439
440	spin_lock_irqsave(&port->lock, flags);
441	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
442	spin_unlock_irqrestore(&port->lock, flags);
443
444	ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
445			  "rda-uart", port);
446	if (ret)
447		return ret;
448
449	spin_lock_irqsave(&port->lock, flags);
450
451	val = rda_uart_read(port, RDA_UART_CTRL);
452	val |= RDA_UART_ENABLE;
453	rda_uart_write(port, val, RDA_UART_CTRL);
454
455	/* enable rx interrupt */
456	val = rda_uart_read(port, RDA_UART_IRQ_MASK);
457	val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
458	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
459
460	spin_unlock_irqrestore(&port->lock, flags);
461
462	return 0;
463}
464
465static void rda_uart_shutdown(struct uart_port *port)
466{
467	unsigned long flags;
468	u32 val;
469
470	spin_lock_irqsave(&port->lock, flags);
471
472	rda_uart_stop_tx(port);
473	rda_uart_stop_rx(port);
474
475	val = rda_uart_read(port, RDA_UART_CTRL);
476	val &= ~RDA_UART_ENABLE;
477	rda_uart_write(port, val, RDA_UART_CTRL);
478
479	spin_unlock_irqrestore(&port->lock, flags);
480}
481
482static const char *rda_uart_type(struct uart_port *port)
483{
484	return (port->type == PORT_RDA) ? "rda-uart" : NULL;
485}
486
487static int rda_uart_request_port(struct uart_port *port)
488{
489	struct platform_device *pdev = to_platform_device(port->dev);
490	struct resource *res;
491
492	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
493	if (!res)
494		return -ENXIO;
495
496	if (!devm_request_mem_region(port->dev, port->mapbase,
497				     resource_size(res), dev_name(port->dev)))
498		return -EBUSY;
499
500	if (port->flags & UPF_IOREMAP) {
501		port->membase = devm_ioremap_nocache(port->dev, port->mapbase,
502						     resource_size(res));
503		if (!port->membase)
504			return -EBUSY;
505	}
506
507	return 0;
508}
509
510static void rda_uart_config_port(struct uart_port *port, int flags)
511{
512	unsigned long irq_flags;
513
514	if (flags & UART_CONFIG_TYPE) {
515		port->type = PORT_RDA;
516		rda_uart_request_port(port);
517	}
518
519	spin_lock_irqsave(&port->lock, irq_flags);
520
521	/* Clear mask, so no surprise interrupts. */
522	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
523
524	/* Clear status register */
525	rda_uart_write(port, 0, RDA_UART_STATUS);
526
527	spin_unlock_irqrestore(&port->lock, irq_flags);
528}
529
530static void rda_uart_release_port(struct uart_port *port)
531{
532	struct platform_device *pdev = to_platform_device(port->dev);
533	struct resource *res;
534
535	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
536	if (!res)
537		return;
538
539	if (port->flags & UPF_IOREMAP) {
540		devm_release_mem_region(port->dev, port->mapbase,
541					resource_size(res));
542		devm_iounmap(port->dev, port->membase);
543		port->membase = NULL;
544	}
545}
546
547static int rda_uart_verify_port(struct uart_port *port,
548				struct serial_struct *ser)
549{
550	if (port->type != PORT_RDA)
551		return -EINVAL;
552
553	if (port->irq != ser->irq)
554		return -EINVAL;
555
556	return 0;
557}
558
559static const struct uart_ops rda_uart_ops = {
560	.tx_empty       = rda_uart_tx_empty,
561	.get_mctrl      = rda_uart_get_mctrl,
562	.set_mctrl      = rda_uart_set_mctrl,
563	.start_tx       = rda_uart_start_tx,
564	.stop_tx        = rda_uart_stop_tx,
565	.stop_rx        = rda_uart_stop_rx,
566	.startup        = rda_uart_startup,
567	.shutdown       = rda_uart_shutdown,
568	.set_termios    = rda_uart_set_termios,
569	.type           = rda_uart_type,
570	.request_port	= rda_uart_request_port,
571	.release_port	= rda_uart_release_port,
572	.config_port	= rda_uart_config_port,
573	.verify_port	= rda_uart_verify_port,
574};
575
576#ifdef CONFIG_SERIAL_RDA_CONSOLE
577
578static void rda_console_putchar(struct uart_port *port, int ch)
579{
580	if (!port->membase)
581		return;
582
583	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
584		cpu_relax();
585
586	rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
587}
588
589static void rda_uart_port_write(struct uart_port *port, const char *s,
590				u_int count)
591{
592	u32 old_irq_mask;
593	unsigned long flags;
594	int locked;
595
596	local_irq_save(flags);
597
598	if (port->sysrq) {
599		locked = 0;
600	} else if (oops_in_progress) {
601		locked = spin_trylock(&port->lock);
602	} else {
603		spin_lock(&port->lock);
604		locked = 1;
605	}
606
607	old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
608	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
609
610	uart_console_write(port, s, count, rda_console_putchar);
611
612	/* wait until all contents have been sent out */
613	while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
614		cpu_relax();
615
616	rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
617
618	if (locked)
619		spin_unlock(&port->lock);
620
621	local_irq_restore(flags);
622}
623
624static void rda_uart_console_write(struct console *co, const char *s,
625				   u_int count)
626{
627	struct rda_uart_port *rda_port;
628
629	rda_port = rda_uart_ports[co->index];
630	if (!rda_port)
631		return;
632
633	rda_uart_port_write(&rda_port->port, s, count);
634}
635
636static int rda_uart_console_setup(struct console *co, char *options)
637{
638	struct rda_uart_port *rda_port;
639	int baud = 921600;
640	int bits = 8;
641	int parity = 'n';
642	int flow = 'n';
643
644	if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
645		return -EINVAL;
646
647	rda_port = rda_uart_ports[co->index];
648	if (!rda_port || !rda_port->port.membase)
649		return -ENODEV;
650
651	if (options)
652		uart_parse_options(options, &baud, &parity, &bits, &flow);
653
654	return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
655}
656
657static struct console rda_uart_console = {
658	.name = RDA_UART_DEV_NAME,
659	.write = rda_uart_console_write,
660	.device = uart_console_device,
661	.setup = rda_uart_console_setup,
662	.flags = CON_PRINTBUFFER,
663	.index = -1,
664	.data = &rda_uart_driver,
665};
666
667static int __init rda_uart_console_init(void)
668{
669	register_console(&rda_uart_console);
670
671	return 0;
672}
673console_initcall(rda_uart_console_init);
674
675static void rda_uart_early_console_write(struct console *co,
676					 const char *s,
677					 u_int count)
678{
679	struct earlycon_device *dev = co->data;
680
681	rda_uart_port_write(&dev->port, s, count);
682}
683
684static int __init
685rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
686{
687	if (!device->port.membase)
688		return -ENODEV;
689
690	device->con->write = rda_uart_early_console_write;
691
692	return 0;
693}
694
695OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
696		    rda_uart_early_console_setup);
697
698#define RDA_UART_CONSOLE (&rda_uart_console)
699#else
700#define RDA_UART_CONSOLE NULL
701#endif /* CONFIG_SERIAL_RDA_CONSOLE */
702
703static struct uart_driver rda_uart_driver = {
704	.owner = THIS_MODULE,
705	.driver_name = "rda-uart",
706	.dev_name = RDA_UART_DEV_NAME,
707	.nr = RDA_UART_PORT_NUM,
708	.cons = RDA_UART_CONSOLE,
709};
710
711static const struct of_device_id rda_uart_dt_matches[] = {
712	{ .compatible = "rda,8810pl-uart" },
713	{ }
714};
715MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
716
717static int rda_uart_probe(struct platform_device *pdev)
718{
719	struct resource *res_mem;
720	struct rda_uart_port *rda_port;
721	int ret, irq;
722
723	if (pdev->dev.of_node)
724		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
725
726	if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
727		dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
728		return -EINVAL;
729	}
730
731	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
732	if (!res_mem) {
733		dev_err(&pdev->dev, "could not get mem\n");
734		return -ENODEV;
735	}
736
737	irq = platform_get_irq(pdev, 0);
738	if (irq < 0)
739		return irq;
740
741	if (rda_uart_ports[pdev->id]) {
742		dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
743		return -EBUSY;
744	}
745
746	rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
747	if (!rda_port)
748		return -ENOMEM;
749
750	rda_port->clk = devm_clk_get(&pdev->dev, NULL);
751	if (IS_ERR(rda_port->clk)) {
752		dev_err(&pdev->dev, "could not get clk\n");
753		return PTR_ERR(rda_port->clk);
754	}
755
756	rda_port->port.dev = &pdev->dev;
757	rda_port->port.regshift = 0;
758	rda_port->port.line = pdev->id;
759	rda_port->port.type = PORT_RDA;
760	rda_port->port.iotype = UPIO_MEM;
761	rda_port->port.mapbase = res_mem->start;
762	rda_port->port.irq = irq;
763	rda_port->port.uartclk = clk_get_rate(rda_port->clk);
764	if (rda_port->port.uartclk == 0) {
765		dev_err(&pdev->dev, "clock rate is zero\n");
766		return -EINVAL;
767	}
768	rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
769			       UPF_LOW_LATENCY;
770	rda_port->port.x_char = 0;
771	rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
772	rda_port->port.ops = &rda_uart_ops;
773
774	rda_uart_ports[pdev->id] = rda_port;
775	platform_set_drvdata(pdev, rda_port);
776
777	ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
778	if (ret)
779		rda_uart_ports[pdev->id] = NULL;
780
781	return ret;
782}
783
784static int rda_uart_remove(struct platform_device *pdev)
785{
786	struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
787
788	uart_remove_one_port(&rda_uart_driver, &rda_port->port);
789	rda_uart_ports[pdev->id] = NULL;
790
791	return 0;
792}
793
794static struct platform_driver rda_uart_platform_driver = {
795	.probe = rda_uart_probe,
796	.remove = rda_uart_remove,
797	.driver = {
798		.name = "rda-uart",
799		.of_match_table = rda_uart_dt_matches,
800	},
801};
802
803static int __init rda_uart_init(void)
804{
805	int ret;
806
807	ret = uart_register_driver(&rda_uart_driver);
808	if (ret)
809		return ret;
810
811	ret = platform_driver_register(&rda_uart_platform_driver);
812	if (ret)
813		uart_unregister_driver(&rda_uart_driver);
814
815	return ret;
816}
817
818static void __exit rda_uart_exit(void)
819{
820	platform_driver_unregister(&rda_uart_platform_driver);
821	uart_unregister_driver(&rda_uart_driver);
822}
823
824module_init(rda_uart_init);
825module_exit(rda_uart_exit);
826
827MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
828MODULE_DESCRIPTION("RDA8810PL serial device driver");
829MODULE_LICENSE("GPL");