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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3* ***************************************************************************
  4* Marvell Armada-3700 Serial Driver
  5* Author: Wilson Ding <dingwei@marvell.com>
  6* Copyright (C) 2015 Marvell International Ltd.
  7* ***************************************************************************
  8*/
  9
 10#include <linux/clk.h>
 11#include <linux/console.h>
 12#include <linux/delay.h>
 13#include <linux/device.h>
 14#include <linux/init.h>
 15#include <linux/io.h>
 16#include <linux/iopoll.h>
 17#include <linux/of.h>
 18#include <linux/of_address.h>
 19#include <linux/of_device.h>
 20#include <linux/of_irq.h>
 21#include <linux/of_platform.h>
 22#include <linux/platform_device.h>
 23#include <linux/serial.h>
 24#include <linux/serial_core.h>
 25#include <linux/slab.h>
 26#include <linux/tty.h>
 27#include <linux/tty_flip.h>
 28
 29/* Register Map */
 30#define UART_STD_RBR		0x00
 31#define UART_EXT_RBR		0x18
 32
 33#define UART_STD_TSH		0x04
 34#define UART_EXT_TSH		0x1C
 35
 36#define UART_STD_CTRL1		0x08
 37#define UART_EXT_CTRL1		0x04
 38#define  CTRL_SOFT_RST		BIT(31)
 39#define  CTRL_TXFIFO_RST	BIT(15)
 40#define  CTRL_RXFIFO_RST	BIT(14)
 41#define  CTRL_SND_BRK_SEQ	BIT(11)
 42#define  CTRL_BRK_DET_INT	BIT(3)
 43#define  CTRL_FRM_ERR_INT	BIT(2)
 44#define  CTRL_PAR_ERR_INT	BIT(1)
 45#define  CTRL_OVR_ERR_INT	BIT(0)
 46#define  CTRL_BRK_INT		(CTRL_BRK_DET_INT | CTRL_FRM_ERR_INT | \
 47				CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT)
 48
 49#define UART_STD_CTRL2		UART_STD_CTRL1
 50#define UART_EXT_CTRL2		0x20
 51#define  CTRL_STD_TX_RDY_INT	BIT(5)
 52#define  CTRL_EXT_TX_RDY_INT	BIT(6)
 53#define  CTRL_STD_RX_RDY_INT	BIT(4)
 54#define  CTRL_EXT_RX_RDY_INT	BIT(5)
 55
 56#define UART_STAT		0x0C
 57#define  STAT_TX_FIFO_EMP	BIT(13)
 58#define  STAT_TX_FIFO_FUL	BIT(11)
 59#define  STAT_TX_EMP		BIT(6)
 60#define  STAT_STD_TX_RDY	BIT(5)
 61#define  STAT_EXT_TX_RDY	BIT(15)
 62#define  STAT_STD_RX_RDY	BIT(4)
 63#define  STAT_EXT_RX_RDY	BIT(14)
 64#define  STAT_BRK_DET		BIT(3)
 65#define  STAT_FRM_ERR		BIT(2)
 66#define  STAT_PAR_ERR		BIT(1)
 67#define  STAT_OVR_ERR		BIT(0)
 68#define  STAT_BRK_ERR		(STAT_BRK_DET | STAT_FRM_ERR \
 69				 | STAT_PAR_ERR | STAT_OVR_ERR)
 70
 71#define UART_BRDV		0x10
 72#define  BRDV_BAUD_MASK         0x3FF
 73
 74#define UART_OSAMP		0x14
 75#define  OSAMP_DEFAULT_DIVISOR	16
 76#define  OSAMP_DIVISORS_MASK	0x3F3F3F3F
 77
 78#define MVEBU_NR_UARTS		2
 79
 80#define MVEBU_UART_TYPE		"mvebu-uart"
 81#define DRIVER_NAME		"mvebu_serial"
 82
 83enum {
 84	/* Either there is only one summed IRQ... */
 85	UART_IRQ_SUM = 0,
 86	/* ...or there are two separate IRQ for RX and TX */
 87	UART_RX_IRQ = 0,
 88	UART_TX_IRQ,
 89	UART_IRQ_COUNT
 90};
 91
 92/* Diverging register offsets */
 93struct uart_regs_layout {
 94	unsigned int rbr;
 95	unsigned int tsh;
 96	unsigned int ctrl;
 97	unsigned int intr;
 98};
 99
100/* Diverging flags */
101struct uart_flags {
102	unsigned int ctrl_tx_rdy_int;
103	unsigned int ctrl_rx_rdy_int;
104	unsigned int stat_tx_rdy;
105	unsigned int stat_rx_rdy;
106};
107
108/* Driver data, a structure for each UART port */
109struct mvebu_uart_driver_data {
110	bool is_ext;
111	struct uart_regs_layout regs;
112	struct uart_flags flags;
113};
114
115/* Saved registers during suspend */
116struct mvebu_uart_pm_regs {
117	unsigned int rbr;
118	unsigned int tsh;
119	unsigned int ctrl;
120	unsigned int intr;
121	unsigned int stat;
122	unsigned int brdv;
123	unsigned int osamp;
124};
125
126/* MVEBU UART driver structure */
127struct mvebu_uart {
128	struct uart_port *port;
129	struct clk *clk;
130	int irq[UART_IRQ_COUNT];
131	struct mvebu_uart_driver_data *data;
132#if defined(CONFIG_PM)
133	struct mvebu_uart_pm_regs pm_regs;
134#endif /* CONFIG_PM */
135};
136
137static struct mvebu_uart *to_mvuart(struct uart_port *port)
138{
139	return (struct mvebu_uart *)port->private_data;
140}
141
142#define IS_EXTENDED(port) (to_mvuart(port)->data->is_ext)
143
144#define UART_RBR(port) (to_mvuart(port)->data->regs.rbr)
145#define UART_TSH(port) (to_mvuart(port)->data->regs.tsh)
146#define UART_CTRL(port) (to_mvuart(port)->data->regs.ctrl)
147#define UART_INTR(port) (to_mvuart(port)->data->regs.intr)
148
149#define CTRL_TX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_tx_rdy_int)
150#define CTRL_RX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_rx_rdy_int)
151#define STAT_TX_RDY(port) (to_mvuart(port)->data->flags.stat_tx_rdy)
152#define STAT_RX_RDY(port) (to_mvuart(port)->data->flags.stat_rx_rdy)
153
154static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS];
155
156/* Core UART Driver Operations */
157static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
158{
159	unsigned long flags;
160	unsigned int st;
161
162	spin_lock_irqsave(&port->lock, flags);
163	st = readl(port->membase + UART_STAT);
164	spin_unlock_irqrestore(&port->lock, flags);
165
166	return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
167}
168
169static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
170{
171	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
172}
173
174static void mvebu_uart_set_mctrl(struct uart_port *port,
175				 unsigned int mctrl)
176{
177/*
178 * Even if we do not support configuring the modem control lines, this
179 * function must be proided to the serial core
180 */
181}
182
183static void mvebu_uart_stop_tx(struct uart_port *port)
184{
185	unsigned int ctl = readl(port->membase + UART_INTR(port));
186
187	ctl &= ~CTRL_TX_RDY_INT(port);
188	writel(ctl, port->membase + UART_INTR(port));
189}
190
191static void mvebu_uart_start_tx(struct uart_port *port)
192{
193	unsigned int ctl;
194	struct circ_buf *xmit = &port->state->xmit;
195
196	if (IS_EXTENDED(port) && !uart_circ_empty(xmit)) {
197		writel(xmit->buf[xmit->tail], port->membase + UART_TSH(port));
198		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
199		port->icount.tx++;
200	}
201
202	ctl = readl(port->membase + UART_INTR(port));
203	ctl |= CTRL_TX_RDY_INT(port);
204	writel(ctl, port->membase + UART_INTR(port));
205}
206
207static void mvebu_uart_stop_rx(struct uart_port *port)
208{
209	unsigned int ctl;
210
211	ctl = readl(port->membase + UART_CTRL(port));
212	ctl &= ~CTRL_BRK_INT;
213	writel(ctl, port->membase + UART_CTRL(port));
214
215	ctl = readl(port->membase + UART_INTR(port));
216	ctl &= ~CTRL_RX_RDY_INT(port);
217	writel(ctl, port->membase + UART_INTR(port));
218}
219
220static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
221{
222	unsigned int ctl;
223	unsigned long flags;
224
225	spin_lock_irqsave(&port->lock, flags);
226	ctl = readl(port->membase + UART_CTRL(port));
227	if (brk == -1)
228		ctl |= CTRL_SND_BRK_SEQ;
229	else
230		ctl &= ~CTRL_SND_BRK_SEQ;
231	writel(ctl, port->membase + UART_CTRL(port));
232	spin_unlock_irqrestore(&port->lock, flags);
233}
234
235static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
236{
237	struct tty_port *tport = &port->state->port;
238	unsigned char ch = 0;
239	char flag = 0;
240
241	do {
242		if (status & STAT_RX_RDY(port)) {
243			ch = readl(port->membase + UART_RBR(port));
244			ch &= 0xff;
245			flag = TTY_NORMAL;
246			port->icount.rx++;
247
248			if (status & STAT_PAR_ERR)
249				port->icount.parity++;
250		}
251
252		if (status & STAT_BRK_DET) {
253			port->icount.brk++;
254			status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
255			if (uart_handle_break(port))
256				goto ignore_char;
257		}
258
259		if (status & STAT_OVR_ERR)
260			port->icount.overrun++;
261
262		if (status & STAT_FRM_ERR)
263			port->icount.frame++;
264
265		if (uart_handle_sysrq_char(port, ch))
266			goto ignore_char;
267
268		if (status & port->ignore_status_mask & STAT_PAR_ERR)
269			status &= ~STAT_RX_RDY(port);
270
271		status &= port->read_status_mask;
272
273		if (status & STAT_PAR_ERR)
274			flag = TTY_PARITY;
275
276		status &= ~port->ignore_status_mask;
277
278		if (status & STAT_RX_RDY(port))
279			tty_insert_flip_char(tport, ch, flag);
280
281		if (status & STAT_BRK_DET)
282			tty_insert_flip_char(tport, 0, TTY_BREAK);
283
284		if (status & STAT_FRM_ERR)
285			tty_insert_flip_char(tport, 0, TTY_FRAME);
286
287		if (status & STAT_OVR_ERR)
288			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
289
290ignore_char:
291		status = readl(port->membase + UART_STAT);
292	} while (status & (STAT_RX_RDY(port) | STAT_BRK_DET));
293
294	tty_flip_buffer_push(tport);
295}
296
297static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status)
298{
299	struct circ_buf *xmit = &port->state->xmit;
300	unsigned int count;
301	unsigned int st;
302
303	if (port->x_char) {
304		writel(port->x_char, port->membase + UART_TSH(port));
305		port->icount.tx++;
306		port->x_char = 0;
307		return;
308	}
309
310	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
311		mvebu_uart_stop_tx(port);
312		return;
313	}
314
315	for (count = 0; count < port->fifosize; count++) {
316		writel(xmit->buf[xmit->tail], port->membase + UART_TSH(port));
317		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
318		port->icount.tx++;
319
320		if (uart_circ_empty(xmit))
321			break;
322
323		st = readl(port->membase + UART_STAT);
324		if (st & STAT_TX_FIFO_FUL)
325			break;
326	}
327
328	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
329		uart_write_wakeup(port);
330
331	if (uart_circ_empty(xmit))
332		mvebu_uart_stop_tx(port);
333}
334
335static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
336{
337	struct uart_port *port = (struct uart_port *)dev_id;
338	unsigned int st = readl(port->membase + UART_STAT);
339
340	if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
341		  STAT_BRK_DET))
342		mvebu_uart_rx_chars(port, st);
343
344	if (st & STAT_TX_RDY(port))
345		mvebu_uart_tx_chars(port, st);
346
347	return IRQ_HANDLED;
348}
349
350static irqreturn_t mvebu_uart_rx_isr(int irq, void *dev_id)
351{
352	struct uart_port *port = (struct uart_port *)dev_id;
353	unsigned int st = readl(port->membase + UART_STAT);
354
355	if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
356			STAT_BRK_DET))
357		mvebu_uart_rx_chars(port, st);
358
359	return IRQ_HANDLED;
360}
361
362static irqreturn_t mvebu_uart_tx_isr(int irq, void *dev_id)
363{
364	struct uart_port *port = (struct uart_port *)dev_id;
365	unsigned int st = readl(port->membase + UART_STAT);
366
367	if (st & STAT_TX_RDY(port))
368		mvebu_uart_tx_chars(port, st);
369
370	return IRQ_HANDLED;
371}
372
373static int mvebu_uart_startup(struct uart_port *port)
374{
375	struct mvebu_uart *mvuart = to_mvuart(port);
376	unsigned int ctl;
377	int ret;
378
379	writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST,
380	       port->membase + UART_CTRL(port));
381	udelay(1);
382
383	/* Clear the error bits of state register before IRQ request */
384	ret = readl(port->membase + UART_STAT);
385	ret |= STAT_BRK_ERR;
386	writel(ret, port->membase + UART_STAT);
387
388	writel(CTRL_BRK_INT, port->membase + UART_CTRL(port));
389
390	ctl = readl(port->membase + UART_INTR(port));
391	ctl |= CTRL_RX_RDY_INT(port);
392	writel(ctl, port->membase + UART_INTR(port));
393
394	if (!mvuart->irq[UART_TX_IRQ]) {
395		/* Old bindings with just one interrupt (UART0 only) */
396		ret = devm_request_irq(port->dev, mvuart->irq[UART_IRQ_SUM],
397				       mvebu_uart_isr, port->irqflags,
398				       dev_name(port->dev), port);
399		if (ret) {
400			dev_err(port->dev, "unable to request IRQ %d\n",
401				mvuart->irq[UART_IRQ_SUM]);
402			return ret;
403		}
404	} else {
405		/* New bindings with an IRQ for RX and TX (both UART) */
406		ret = devm_request_irq(port->dev, mvuart->irq[UART_RX_IRQ],
407				       mvebu_uart_rx_isr, port->irqflags,
408				       dev_name(port->dev), port);
409		if (ret) {
410			dev_err(port->dev, "unable to request IRQ %d\n",
411				mvuart->irq[UART_RX_IRQ]);
412			return ret;
413		}
414
415		ret = devm_request_irq(port->dev, mvuart->irq[UART_TX_IRQ],
416				       mvebu_uart_tx_isr, port->irqflags,
417				       dev_name(port->dev),
418				       port);
419		if (ret) {
420			dev_err(port->dev, "unable to request IRQ %d\n",
421				mvuart->irq[UART_TX_IRQ]);
422			devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ],
423				      port);
424			return ret;
425		}
426	}
427
428	return 0;
429}
430
431static void mvebu_uart_shutdown(struct uart_port *port)
432{
433	struct mvebu_uart *mvuart = to_mvuart(port);
434
435	writel(0, port->membase + UART_INTR(port));
436
437	if (!mvuart->irq[UART_TX_IRQ]) {
438		devm_free_irq(port->dev, mvuart->irq[UART_IRQ_SUM], port);
439	} else {
440		devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ], port);
441		devm_free_irq(port->dev, mvuart->irq[UART_TX_IRQ], port);
442	}
443}
444
445static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
446{
447	unsigned int d_divisor, m_divisor;
448	u32 brdv, osamp;
449
450	if (!port->uartclk)
451		return -EOPNOTSUPP;
452
453	/*
454	 * The baudrate is derived from the UART clock thanks to two divisors:
455	 *   > D ("baud generator"): can divide the clock from 2 to 2^10 - 1.
456	 *   > M ("fractional divisor"): allows a better accuracy for
457	 *     baudrates higher than 230400.
458	 *
459	 * As the derivation of M is rather complicated, the code sticks to its
460	 * default value (x16) when all the prescalers are zeroed, and only
461	 * makes use of D to configure the desired baudrate.
462	 */
463	m_divisor = OSAMP_DEFAULT_DIVISOR;
464	d_divisor = DIV_ROUND_CLOSEST(port->uartclk, baud * m_divisor);
465
466	brdv = readl(port->membase + UART_BRDV);
467	brdv &= ~BRDV_BAUD_MASK;
468	brdv |= d_divisor;
469	writel(brdv, port->membase + UART_BRDV);
470
471	osamp = readl(port->membase + UART_OSAMP);
472	osamp &= ~OSAMP_DIVISORS_MASK;
473	writel(osamp, port->membase + UART_OSAMP);
474
475	return 0;
476}
477
478static void mvebu_uart_set_termios(struct uart_port *port,
479				   struct ktermios *termios,
480				   struct ktermios *old)
481{
482	unsigned long flags;
483	unsigned int baud, min_baud, max_baud;
484
485	spin_lock_irqsave(&port->lock, flags);
486
487	port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
488		STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
489
490	if (termios->c_iflag & INPCK)
491		port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR;
492
493	port->ignore_status_mask = 0;
494	if (termios->c_iflag & IGNPAR)
495		port->ignore_status_mask |=
496			STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR;
497
498	if ((termios->c_cflag & CREAD) == 0)
499		port->ignore_status_mask |= STAT_RX_RDY(port) | STAT_BRK_ERR;
500
501	/*
502	 * Maximal divisor is 1023 * 16 when using default (x16) scheme.
503	 * Maximum achievable frequency with simple baudrate divisor is 230400.
504	 * Since the error per bit frame would be of more than 15%, achieving
505	 * higher frequencies would require to implement the fractional divisor
506	 * feature.
507	 */
508	min_baud = DIV_ROUND_UP(port->uartclk, 1023 * 16);
509	max_baud = 230400;
510
511	baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud);
512	if (mvebu_uart_baud_rate_set(port, baud)) {
513		/* No clock available, baudrate cannot be changed */
514		if (old)
515			baud = uart_get_baud_rate(port, old, NULL,
516						  min_baud, max_baud);
517	} else {
518		tty_termios_encode_baud_rate(termios, baud, baud);
519		uart_update_timeout(port, termios->c_cflag, baud);
520	}
521
522	/* Only the following flag changes are supported */
523	if (old) {
524		termios->c_iflag &= INPCK | IGNPAR;
525		termios->c_iflag |= old->c_iflag & ~(INPCK | IGNPAR);
526		termios->c_cflag &= CREAD | CBAUD;
527		termios->c_cflag |= old->c_cflag & ~(CREAD | CBAUD);
528		termios->c_cflag |= CS8;
529	}
530
531	spin_unlock_irqrestore(&port->lock, flags);
532}
533
534static const char *mvebu_uart_type(struct uart_port *port)
535{
536	return MVEBU_UART_TYPE;
537}
538
539static void mvebu_uart_release_port(struct uart_port *port)
540{
541	/* Nothing to do here */
542}
543
544static int mvebu_uart_request_port(struct uart_port *port)
545{
546	return 0;
547}
548
549#ifdef CONFIG_CONSOLE_POLL
550static int mvebu_uart_get_poll_char(struct uart_port *port)
551{
552	unsigned int st = readl(port->membase + UART_STAT);
553
554	if (!(st & STAT_RX_RDY(port)))
555		return NO_POLL_CHAR;
556
557	return readl(port->membase + UART_RBR(port));
558}
559
560static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c)
561{
562	unsigned int st;
563
564	for (;;) {
565		st = readl(port->membase + UART_STAT);
566
567		if (!(st & STAT_TX_FIFO_FUL))
568			break;
569
570		udelay(1);
571	}
572
573	writel(c, port->membase + UART_TSH(port));
574}
575#endif
576
577static const struct uart_ops mvebu_uart_ops = {
578	.tx_empty	= mvebu_uart_tx_empty,
579	.set_mctrl	= mvebu_uart_set_mctrl,
580	.get_mctrl	= mvebu_uart_get_mctrl,
581	.stop_tx	= mvebu_uart_stop_tx,
582	.start_tx	= mvebu_uart_start_tx,
583	.stop_rx	= mvebu_uart_stop_rx,
584	.break_ctl	= mvebu_uart_break_ctl,
585	.startup	= mvebu_uart_startup,
586	.shutdown	= mvebu_uart_shutdown,
587	.set_termios	= mvebu_uart_set_termios,
588	.type		= mvebu_uart_type,
589	.release_port	= mvebu_uart_release_port,
590	.request_port	= mvebu_uart_request_port,
591#ifdef CONFIG_CONSOLE_POLL
592	.poll_get_char	= mvebu_uart_get_poll_char,
593	.poll_put_char	= mvebu_uart_put_poll_char,
594#endif
595};
596
597/* Console Driver Operations  */
598
599#ifdef CONFIG_SERIAL_MVEBU_CONSOLE
600/* Early Console */
601static void mvebu_uart_putc(struct uart_port *port, int c)
602{
603	unsigned int st;
604
605	for (;;) {
606		st = readl(port->membase + UART_STAT);
607		if (!(st & STAT_TX_FIFO_FUL))
608			break;
609	}
610
611	/* At early stage, DT is not parsed yet, only use UART0 */
612	writel(c, port->membase + UART_STD_TSH);
613
614	for (;;) {
615		st = readl(port->membase + UART_STAT);
616		if (st & STAT_TX_FIFO_EMP)
617			break;
618	}
619}
620
621static void mvebu_uart_putc_early_write(struct console *con,
622					const char *s,
623					unsigned int n)
624{
625	struct earlycon_device *dev = con->data;
626
627	uart_console_write(&dev->port, s, n, mvebu_uart_putc);
628}
629
630static int __init
631mvebu_uart_early_console_setup(struct earlycon_device *device,
632			       const char *opt)
633{
634	if (!device->port.membase)
635		return -ENODEV;
636
637	device->con->write = mvebu_uart_putc_early_write;
638
639	return 0;
640}
641
642EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup);
643OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart",
644		    mvebu_uart_early_console_setup);
645
646static void wait_for_xmitr(struct uart_port *port)
647{
648	u32 val;
649
650	readl_poll_timeout_atomic(port->membase + UART_STAT, val,
651				  (val & STAT_TX_RDY(port)), 1, 10000);
652}
653
654static void wait_for_xmite(struct uart_port *port)
655{
656	u32 val;
657
658	readl_poll_timeout_atomic(port->membase + UART_STAT, val,
659				  (val & STAT_TX_EMP), 1, 10000);
660}
661
662static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
663{
664	wait_for_xmitr(port);
665	writel(ch, port->membase + UART_TSH(port));
666}
667
668static void mvebu_uart_console_write(struct console *co, const char *s,
669				     unsigned int count)
670{
671	struct uart_port *port = &mvebu_uart_ports[co->index];
672	unsigned long flags;
673	unsigned int ier, intr, ctl;
674	int locked = 1;
675
676	if (oops_in_progress)
677		locked = spin_trylock_irqsave(&port->lock, flags);
678	else
679		spin_lock_irqsave(&port->lock, flags);
680
681	ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
682	intr = readl(port->membase + UART_INTR(port)) &
683		(CTRL_RX_RDY_INT(port) | CTRL_TX_RDY_INT(port));
684	writel(0, port->membase + UART_CTRL(port));
685	writel(0, port->membase + UART_INTR(port));
686
687	uart_console_write(port, s, count, mvebu_uart_console_putchar);
688
689	wait_for_xmite(port);
690
691	if (ier)
692		writel(ier, port->membase + UART_CTRL(port));
693
694	if (intr) {
695		ctl = intr | readl(port->membase + UART_INTR(port));
696		writel(ctl, port->membase + UART_INTR(port));
697	}
698
699	if (locked)
700		spin_unlock_irqrestore(&port->lock, flags);
701}
702
703static int mvebu_uart_console_setup(struct console *co, char *options)
704{
705	struct uart_port *port;
706	int baud = 9600;
707	int bits = 8;
708	int parity = 'n';
709	int flow = 'n';
710
711	if (co->index < 0 || co->index >= MVEBU_NR_UARTS)
712		return -EINVAL;
713
714	port = &mvebu_uart_ports[co->index];
715
716	if (!port->mapbase || !port->membase) {
717		pr_debug("console on ttyMV%i not present\n", co->index);
718		return -ENODEV;
719	}
720
721	if (options)
722		uart_parse_options(options, &baud, &parity, &bits, &flow);
723
724	return uart_set_options(port, co, baud, parity, bits, flow);
725}
726
727static struct uart_driver mvebu_uart_driver;
728
729static struct console mvebu_uart_console = {
730	.name	= "ttyMV",
731	.write	= mvebu_uart_console_write,
732	.device	= uart_console_device,
733	.setup	= mvebu_uart_console_setup,
734	.flags	= CON_PRINTBUFFER,
735	.index	= -1,
736	.data	= &mvebu_uart_driver,
737};
738
739static int __init mvebu_uart_console_init(void)
740{
741	register_console(&mvebu_uart_console);
742	return 0;
743}
744
745console_initcall(mvebu_uart_console_init);
746
747
748#endif /* CONFIG_SERIAL_MVEBU_CONSOLE */
749
750static struct uart_driver mvebu_uart_driver = {
751	.owner			= THIS_MODULE,
752	.driver_name		= DRIVER_NAME,
753	.dev_name		= "ttyMV",
754	.nr			= MVEBU_NR_UARTS,
755#ifdef CONFIG_SERIAL_MVEBU_CONSOLE
756	.cons			= &mvebu_uart_console,
757#endif
758};
759
760#if defined(CONFIG_PM)
761static int mvebu_uart_suspend(struct device *dev)
762{
763	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
764	struct uart_port *port = mvuart->port;
765
766	uart_suspend_port(&mvebu_uart_driver, port);
767
768	mvuart->pm_regs.rbr = readl(port->membase + UART_RBR(port));
769	mvuart->pm_regs.tsh = readl(port->membase + UART_TSH(port));
770	mvuart->pm_regs.ctrl = readl(port->membase + UART_CTRL(port));
771	mvuart->pm_regs.intr = readl(port->membase + UART_INTR(port));
772	mvuart->pm_regs.stat = readl(port->membase + UART_STAT);
773	mvuart->pm_regs.brdv = readl(port->membase + UART_BRDV);
774	mvuart->pm_regs.osamp = readl(port->membase + UART_OSAMP);
775
776	device_set_wakeup_enable(dev, true);
777
778	return 0;
779}
780
781static int mvebu_uart_resume(struct device *dev)
782{
783	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
784	struct uart_port *port = mvuart->port;
785
786	writel(mvuart->pm_regs.rbr, port->membase + UART_RBR(port));
787	writel(mvuart->pm_regs.tsh, port->membase + UART_TSH(port));
788	writel(mvuart->pm_regs.ctrl, port->membase + UART_CTRL(port));
789	writel(mvuart->pm_regs.intr, port->membase + UART_INTR(port));
790	writel(mvuart->pm_regs.stat, port->membase + UART_STAT);
791	writel(mvuart->pm_regs.brdv, port->membase + UART_BRDV);
792	writel(mvuart->pm_regs.osamp, port->membase + UART_OSAMP);
793
794	uart_resume_port(&mvebu_uart_driver, port);
795
796	return 0;
797}
798
799static const struct dev_pm_ops mvebu_uart_pm_ops = {
800	.suspend        = mvebu_uart_suspend,
801	.resume         = mvebu_uart_resume,
802};
803#endif /* CONFIG_PM */
804
805static const struct of_device_id mvebu_uart_of_match[];
806
807/* Counter to keep track of each UART port id when not using CONFIG_OF */
808static int uart_num_counter;
809
810static int mvebu_uart_probe(struct platform_device *pdev)
811{
812	struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
813	const struct of_device_id *match = of_match_device(mvebu_uart_of_match,
814							   &pdev->dev);
815	struct uart_port *port;
816	struct mvebu_uart *mvuart;
817	int id, irq;
818
819	if (!reg) {
820		dev_err(&pdev->dev, "no registers defined\n");
821		return -EINVAL;
822	}
823
824	/* Assume that all UART ports have a DT alias or none has */
825	id = of_alias_get_id(pdev->dev.of_node, "serial");
826	if (!pdev->dev.of_node || id < 0)
827		pdev->id = uart_num_counter++;
828	else
829		pdev->id = id;
830
831	if (pdev->id >= MVEBU_NR_UARTS) {
832		dev_err(&pdev->dev, "cannot have more than %d UART ports\n",
833			MVEBU_NR_UARTS);
834		return -EINVAL;
835	}
836
837	port = &mvebu_uart_ports[pdev->id];
838
839	spin_lock_init(&port->lock);
840
841	port->dev        = &pdev->dev;
842	port->type       = PORT_MVEBU;
843	port->ops        = &mvebu_uart_ops;
844	port->regshift   = 0;
845
846	port->fifosize   = 32;
847	port->iotype     = UPIO_MEM32;
848	port->flags      = UPF_FIXED_PORT;
849	port->line       = pdev->id;
850
851	/*
852	 * IRQ number is not stored in this structure because we may have two of
853	 * them per port (RX and TX). Instead, use the driver UART structure
854	 * array so called ->irq[].
855	 */
856	port->irq        = 0;
857	port->irqflags   = 0;
858	port->mapbase    = reg->start;
859
860	port->membase = devm_ioremap_resource(&pdev->dev, reg);
861	if (IS_ERR(port->membase))
862		return PTR_ERR(port->membase);
863
864	mvuart = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart),
865			      GFP_KERNEL);
866	if (!mvuart)
867		return -ENOMEM;
868
869	/* Get controller data depending on the compatible string */
870	mvuart->data = (struct mvebu_uart_driver_data *)match->data;
871	mvuart->port = port;
872
873	port->private_data = mvuart;
874	platform_set_drvdata(pdev, mvuart);
875
876	/* Get fixed clock frequency */
877	mvuart->clk = devm_clk_get(&pdev->dev, NULL);
878	if (IS_ERR(mvuart->clk)) {
879		if (PTR_ERR(mvuart->clk) == -EPROBE_DEFER)
880			return PTR_ERR(mvuart->clk);
881
882		if (IS_EXTENDED(port)) {
883			dev_err(&pdev->dev, "unable to get UART clock\n");
884			return PTR_ERR(mvuart->clk);
885		}
886	} else {
887		if (!clk_prepare_enable(mvuart->clk))
888			port->uartclk = clk_get_rate(mvuart->clk);
889	}
890
891	/* Manage interrupts */
892	if (platform_irq_count(pdev) == 1) {
893		/* Old bindings: no name on the single unamed UART0 IRQ */
894		irq = platform_get_irq(pdev, 0);
895		if (irq < 0)
896			return irq;
897
898		mvuart->irq[UART_IRQ_SUM] = irq;
899	} else {
900		/*
901		 * New bindings: named interrupts (RX, TX) for both UARTS,
902		 * only make use of uart-rx and uart-tx interrupts, do not use
903		 * uart-sum of UART0 port.
904		 */
905		irq = platform_get_irq_byname(pdev, "uart-rx");
906		if (irq < 0)
907			return irq;
908
909		mvuart->irq[UART_RX_IRQ] = irq;
910
911		irq = platform_get_irq_byname(pdev, "uart-tx");
912		if (irq < 0)
913			return irq;
914
915		mvuart->irq[UART_TX_IRQ] = irq;
916	}
917
918	/* UART Soft Reset*/
919	writel(CTRL_SOFT_RST, port->membase + UART_CTRL(port));
920	udelay(1);
921	writel(0, port->membase + UART_CTRL(port));
922
923	return uart_add_one_port(&mvebu_uart_driver, port);
924}
925
926static struct mvebu_uart_driver_data uart_std_driver_data = {
927	.is_ext = false,
928	.regs.rbr = UART_STD_RBR,
929	.regs.tsh = UART_STD_TSH,
930	.regs.ctrl = UART_STD_CTRL1,
931	.regs.intr = UART_STD_CTRL2,
932	.flags.ctrl_tx_rdy_int = CTRL_STD_TX_RDY_INT,
933	.flags.ctrl_rx_rdy_int = CTRL_STD_RX_RDY_INT,
934	.flags.stat_tx_rdy = STAT_STD_TX_RDY,
935	.flags.stat_rx_rdy = STAT_STD_RX_RDY,
936};
937
938static struct mvebu_uart_driver_data uart_ext_driver_data = {
939	.is_ext = true,
940	.regs.rbr = UART_EXT_RBR,
941	.regs.tsh = UART_EXT_TSH,
942	.regs.ctrl = UART_EXT_CTRL1,
943	.regs.intr = UART_EXT_CTRL2,
944	.flags.ctrl_tx_rdy_int = CTRL_EXT_TX_RDY_INT,
945	.flags.ctrl_rx_rdy_int = CTRL_EXT_RX_RDY_INT,
946	.flags.stat_tx_rdy = STAT_EXT_TX_RDY,
947	.flags.stat_rx_rdy = STAT_EXT_RX_RDY,
948};
949
950/* Match table for of_platform binding */
951static const struct of_device_id mvebu_uart_of_match[] = {
952	{
953		.compatible = "marvell,armada-3700-uart",
954		.data = (void *)&uart_std_driver_data,
955	},
956	{
957		.compatible = "marvell,armada-3700-uart-ext",
958		.data = (void *)&uart_ext_driver_data,
959	},
960	{}
961};
962
963static struct platform_driver mvebu_uart_platform_driver = {
964	.probe	= mvebu_uart_probe,
965	.driver	= {
966		.name  = "mvebu-uart",
967		.of_match_table = of_match_ptr(mvebu_uart_of_match),
968		.suppress_bind_attrs = true,
969#if defined(CONFIG_PM)
970		.pm	= &mvebu_uart_pm_ops,
971#endif /* CONFIG_PM */
972	},
973};
974
975static int __init mvebu_uart_init(void)
976{
977	int ret;
978
979	ret = uart_register_driver(&mvebu_uart_driver);
980	if (ret)
981		return ret;
982
983	ret = platform_driver_register(&mvebu_uart_platform_driver);
984	if (ret)
985		uart_unregister_driver(&mvebu_uart_driver);
986
987	return ret;
988}
989arch_initcall(mvebu_uart_init);