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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Freescale linflexuart serial port driver
  4 *
  5 * Copyright 2012-2016 Freescale Semiconductor, Inc.
  6 * Copyright 2017-2019 NXP
  7 */
  8
  9#if defined(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE) && \
 10	defined(CONFIG_MAGIC_SYSRQ)
 11#define SUPPORT_SYSRQ
 12#endif
 13
 14#include <linux/console.h>
 15#include <linux/io.h>
 16#include <linux/irq.h>
 17#include <linux/module.h>
 18#include <linux/of.h>
 19#include <linux/of_device.h>
 20#include <linux/serial_core.h>
 21#include <linux/slab.h>
 22#include <linux/tty_flip.h>
 23#include <linux/delay.h>
 24
 25/* All registers are 32-bit width */
 26
 27#define LINCR1	0x0000	/* LIN control register				*/
 28#define LINIER	0x0004	/* LIN interrupt enable register		*/
 29#define LINSR	0x0008	/* LIN status register				*/
 30#define LINESR	0x000C	/* LIN error status register			*/
 31#define UARTCR	0x0010	/* UART mode control register			*/
 32#define UARTSR	0x0014	/* UART mode status register			*/
 33#define LINTCSR	0x0018	/* LIN timeout control status register		*/
 34#define LINOCR	0x001C	/* LIN output compare register			*/
 35#define LINTOCR	0x0020	/* LIN timeout control register			*/
 36#define LINFBRR	0x0024	/* LIN fractional baud rate register		*/
 37#define LINIBRR	0x0028	/* LIN integer baud rate register		*/
 38#define LINCFR	0x002C	/* LIN checksum field register			*/
 39#define LINCR2	0x0030	/* LIN control register 2			*/
 40#define BIDR	0x0034	/* Buffer identifier register			*/
 41#define BDRL	0x0038	/* Buffer data register least significant	*/
 42#define BDRM	0x003C	/* Buffer data register most significant	*/
 43#define IFER	0x0040	/* Identifier filter enable register		*/
 44#define IFMI	0x0044	/* Identifier filter match index		*/
 45#define IFMR	0x0048	/* Identifier filter mode register		*/
 46#define GCR	0x004C	/* Global control register			*/
 47#define UARTPTO	0x0050	/* UART preset timeout register			*/
 48#define UARTCTO	0x0054	/* UART current timeout register		*/
 49
 50/*
 51 * Register field definitions
 52 */
 53
 54#define LINFLEXD_LINCR1_INIT		BIT(0)
 55#define LINFLEXD_LINCR1_MME		BIT(4)
 56#define LINFLEXD_LINCR1_BF		BIT(7)
 57
 58#define LINFLEXD_LINSR_LINS_INITMODE	BIT(12)
 59#define LINFLEXD_LINSR_LINS_MASK	(0xF << 12)
 60
 61#define LINFLEXD_LINIER_SZIE		BIT(15)
 62#define LINFLEXD_LINIER_OCIE		BIT(14)
 63#define LINFLEXD_LINIER_BEIE		BIT(13)
 64#define LINFLEXD_LINIER_CEIE		BIT(12)
 65#define LINFLEXD_LINIER_HEIE		BIT(11)
 66#define LINFLEXD_LINIER_FEIE		BIT(8)
 67#define LINFLEXD_LINIER_BOIE		BIT(7)
 68#define LINFLEXD_LINIER_LSIE		BIT(6)
 69#define LINFLEXD_LINIER_WUIE		BIT(5)
 70#define LINFLEXD_LINIER_DBFIE		BIT(4)
 71#define LINFLEXD_LINIER_DBEIETOIE	BIT(3)
 72#define LINFLEXD_LINIER_DRIE		BIT(2)
 73#define LINFLEXD_LINIER_DTIE		BIT(1)
 74#define LINFLEXD_LINIER_HRIE		BIT(0)
 75
 76#define LINFLEXD_UARTCR_OSR_MASK	(0xF << 24)
 77#define LINFLEXD_UARTCR_OSR(uartcr)	(((uartcr) \
 78					& LINFLEXD_UARTCR_OSR_MASK) >> 24)
 79
 80#define LINFLEXD_UARTCR_ROSE		BIT(23)
 81
 82#define LINFLEXD_UARTCR_RFBM		BIT(9)
 83#define LINFLEXD_UARTCR_TFBM		BIT(8)
 84#define LINFLEXD_UARTCR_WL1		BIT(7)
 85#define LINFLEXD_UARTCR_PC1		BIT(6)
 86
 87#define LINFLEXD_UARTCR_RXEN		BIT(5)
 88#define LINFLEXD_UARTCR_TXEN		BIT(4)
 89#define LINFLEXD_UARTCR_PC0		BIT(3)
 90
 91#define LINFLEXD_UARTCR_PCE		BIT(2)
 92#define LINFLEXD_UARTCR_WL0		BIT(1)
 93#define LINFLEXD_UARTCR_UART		BIT(0)
 94
 95#define LINFLEXD_UARTSR_SZF		BIT(15)
 96#define LINFLEXD_UARTSR_OCF		BIT(14)
 97#define LINFLEXD_UARTSR_PE3		BIT(13)
 98#define LINFLEXD_UARTSR_PE2		BIT(12)
 99#define LINFLEXD_UARTSR_PE1		BIT(11)
100#define LINFLEXD_UARTSR_PE0		BIT(10)
101#define LINFLEXD_UARTSR_RMB		BIT(9)
102#define LINFLEXD_UARTSR_FEF		BIT(8)
103#define LINFLEXD_UARTSR_BOF		BIT(7)
104#define LINFLEXD_UARTSR_RPS		BIT(6)
105#define LINFLEXD_UARTSR_WUF		BIT(5)
106#define LINFLEXD_UARTSR_4		BIT(4)
107
108#define LINFLEXD_UARTSR_TO		BIT(3)
109
110#define LINFLEXD_UARTSR_DRFRFE		BIT(2)
111#define LINFLEXD_UARTSR_DTFTFF		BIT(1)
112#define LINFLEXD_UARTSR_NF		BIT(0)
113#define LINFLEXD_UARTSR_PE		(LINFLEXD_UARTSR_PE0 |\
114					 LINFLEXD_UARTSR_PE1 |\
115					 LINFLEXD_UARTSR_PE2 |\
116					 LINFLEXD_UARTSR_PE3)
117
118#define LINFLEX_LDIV_MULTIPLIER		(16)
119
120#define DRIVER_NAME	"fsl-linflexuart"
121#define DEV_NAME	"ttyLF"
122#define UART_NR		4
123
124#define EARLYCON_BUFFER_INITIAL_CAP	8
125
126#define PREINIT_DELAY			2000 /* us */
127
128static const struct of_device_id linflex_dt_ids[] = {
129	{
130		.compatible = "fsl,s32v234-linflexuart",
131	},
132	{ /* sentinel */ }
133};
134MODULE_DEVICE_TABLE(of, linflex_dt_ids);
135
136#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
137static struct uart_port *earlycon_port;
138static bool linflex_earlycon_same_instance;
139static DEFINE_SPINLOCK(init_lock);
140static bool during_init;
141
142static struct {
143	char *content;
144	unsigned int len, cap;
145} earlycon_buf;
146#endif
147
148static void linflex_stop_tx(struct uart_port *port)
149{
150	unsigned long ier;
151
152	ier = readl(port->membase + LINIER);
153	ier &= ~(LINFLEXD_LINIER_DTIE);
154	writel(ier, port->membase + LINIER);
155}
156
157static void linflex_stop_rx(struct uart_port *port)
158{
159	unsigned long ier;
160
161	ier = readl(port->membase + LINIER);
162	writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER);
163}
164
165static inline void linflex_transmit_buffer(struct uart_port *sport)
166{
167	struct circ_buf *xmit = &sport->state->xmit;
168	unsigned char c;
169	unsigned long status;
170
171	while (!uart_circ_empty(xmit)) {
172		c = xmit->buf[xmit->tail];
173		writeb(c, sport->membase + BDRL);
174
175		/* Waiting for data transmission completed. */
176		while (((status = readl(sport->membase + UARTSR)) &
177					LINFLEXD_UARTSR_DTFTFF) !=
178					LINFLEXD_UARTSR_DTFTFF)
179			;
180
181		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
182		sport->icount.tx++;
183
184		writel(status | LINFLEXD_UARTSR_DTFTFF,
185		       sport->membase + UARTSR);
186	}
187
188	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
189		uart_write_wakeup(sport);
190
191	if (uart_circ_empty(xmit))
192		linflex_stop_tx(sport);
193}
194
195static void linflex_start_tx(struct uart_port *port)
196{
197	unsigned long ier;
198
199	linflex_transmit_buffer(port);
200	ier = readl(port->membase + LINIER);
201	writel(ier | LINFLEXD_LINIER_DTIE, port->membase + LINIER);
202}
203
204static irqreturn_t linflex_txint(int irq, void *dev_id)
205{
206	struct uart_port *sport = dev_id;
207	struct circ_buf *xmit = &sport->state->xmit;
208	unsigned long flags;
209	unsigned long status;
210
211	spin_lock_irqsave(&sport->lock, flags);
212
213	if (sport->x_char) {
214		writeb(sport->x_char, sport->membase + BDRL);
215
216		/* waiting for data transmission completed */
217		while (((status = readl(sport->membase + UARTSR)) &
218			LINFLEXD_UARTSR_DTFTFF) != LINFLEXD_UARTSR_DTFTFF)
219			;
220
221		writel(status | LINFLEXD_UARTSR_DTFTFF,
222		       sport->membase + UARTSR);
223
224		goto out;
225	}
226
227	if (uart_circ_empty(xmit) || uart_tx_stopped(sport)) {
228		linflex_stop_tx(sport);
229		goto out;
230	}
231
232	linflex_transmit_buffer(sport);
233
234	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
235		uart_write_wakeup(sport);
236
237out:
238	spin_unlock_irqrestore(&sport->lock, flags);
239	return IRQ_HANDLED;
240}
241
242static irqreturn_t linflex_rxint(int irq, void *dev_id)
243{
244	struct uart_port *sport = dev_id;
245	unsigned int flg;
246	struct tty_port *port = &sport->state->port;
247	unsigned long flags, status;
248	unsigned char rx;
249	bool brk;
250
251	spin_lock_irqsave(&sport->lock, flags);
252
253	status = readl(sport->membase + UARTSR);
254	while (status & LINFLEXD_UARTSR_RMB) {
255		rx = readb(sport->membase + BDRM);
256		brk = false;
257		flg = TTY_NORMAL;
258		sport->icount.rx++;
259
260		if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_SZF |
261			      LINFLEXD_UARTSR_FEF | LINFLEXD_UARTSR_PE)) {
262			if (status & LINFLEXD_UARTSR_SZF)
263				status |= LINFLEXD_UARTSR_SZF;
264			if (status & LINFLEXD_UARTSR_BOF)
265				status |= LINFLEXD_UARTSR_BOF;
266			if (status & LINFLEXD_UARTSR_FEF) {
267				if (!rx)
268					brk = true;
269				status |= LINFLEXD_UARTSR_FEF;
270			}
271			if (status & LINFLEXD_UARTSR_PE)
272				status |=  LINFLEXD_UARTSR_PE;
273		}
274
275		writel(status | LINFLEXD_UARTSR_RMB | LINFLEXD_UARTSR_DRFRFE,
276		       sport->membase + UARTSR);
277		status = readl(sport->membase + UARTSR);
278
279		if (brk) {
280			uart_handle_break(sport);
281		} else {
282#ifdef SUPPORT_SYSRQ
283			if (uart_handle_sysrq_char(sport, (unsigned char)rx))
284				continue;
285#endif
286			tty_insert_flip_char(port, rx, flg);
287		}
288	}
289
290	spin_unlock_irqrestore(&sport->lock, flags);
291
292	tty_flip_buffer_push(port);
293
294	return IRQ_HANDLED;
295}
296
297static irqreturn_t linflex_int(int irq, void *dev_id)
298{
299	struct uart_port *sport = dev_id;
300	unsigned long status;
301
302	status = readl(sport->membase + UARTSR);
303
304	if (status & LINFLEXD_UARTSR_DRFRFE)
305		linflex_rxint(irq, dev_id);
306	if (status & LINFLEXD_UARTSR_DTFTFF)
307		linflex_txint(irq, dev_id);
308
309	return IRQ_HANDLED;
310}
311
312/* return TIOCSER_TEMT when transmitter is not busy */
313static unsigned int linflex_tx_empty(struct uart_port *port)
314{
315	unsigned long status;
316
317	status = readl(port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF;
318
319	return status ? TIOCSER_TEMT : 0;
320}
321
322static unsigned int linflex_get_mctrl(struct uart_port *port)
323{
324	return 0;
325}
326
327static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl)
328{
329}
330
331static void linflex_break_ctl(struct uart_port *port, int break_state)
332{
333}
334
335static void linflex_setup_watermark(struct uart_port *sport)
336{
337	unsigned long cr, ier, cr1;
338
339	/* Disable transmission/reception */
340	ier = readl(sport->membase + LINIER);
341	ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
342	writel(ier, sport->membase + LINIER);
343
344	cr = readl(sport->membase + UARTCR);
345	cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN);
346	writel(cr, sport->membase + UARTCR);
347
348	/* Enter initialization mode by setting INIT bit */
349
350	/* set the Linflex in master mode and activate by-pass filter */
351	cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME
352	      | LINFLEXD_LINCR1_INIT;
353	writel(cr1, sport->membase + LINCR1);
354
355	/* wait for init mode entry */
356	while ((readl(sport->membase + LINSR)
357		& LINFLEXD_LINSR_LINS_MASK)
358		!= LINFLEXD_LINSR_LINS_INITMODE)
359		;
360
361	/*
362	 *	UART = 0x1;		- Linflex working in UART mode
363	 *	TXEN = 0x1;		- Enable transmission of data now
364	 *	RXEn = 0x1;		- Receiver enabled
365	 *	WL0 = 0x1;		- 8 bit data
366	 *	PCE = 0x0;		- No parity
367	 */
368
369	/* set UART bit to allow writing other bits */
370	writel(LINFLEXD_UARTCR_UART, sport->membase + UARTCR);
371
372	cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN |
373	      LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART);
374
375	writel(cr, sport->membase + UARTCR);
376
377	cr1 &= ~(LINFLEXD_LINCR1_INIT);
378
379	writel(cr1, sport->membase + LINCR1);
380
381	ier = readl(sport->membase + LINIER);
382	ier |= LINFLEXD_LINIER_DRIE;
383	ier |= LINFLEXD_LINIER_DTIE;
384
385	writel(ier, sport->membase + LINIER);
386}
387
388static int linflex_startup(struct uart_port *port)
389{
390	int ret = 0;
391	unsigned long flags;
392
393	spin_lock_irqsave(&port->lock, flags);
394
395	linflex_setup_watermark(port);
396
397	spin_unlock_irqrestore(&port->lock, flags);
398
399	ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
400			       DRIVER_NAME, port);
401
402	return ret;
403}
404
405static void linflex_shutdown(struct uart_port *port)
406{
407	unsigned long ier;
408	unsigned long flags;
409
410	spin_lock_irqsave(&port->lock, flags);
411
412	/* disable interrupts */
413	ier = readl(port->membase + LINIER);
414	ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
415	writel(ier, port->membase + LINIER);
416
417	spin_unlock_irqrestore(&port->lock, flags);
418
419	devm_free_irq(port->dev, port->irq, port);
420}
421
422static void
423linflex_set_termios(struct uart_port *port, struct ktermios *termios,
424		    struct ktermios *old)
425{
426	unsigned long flags;
427	unsigned long cr, old_cr, cr1;
428	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
429
430	cr = readl(port->membase + UARTCR);
431	old_cr = cr;
432
433	/* Enter initialization mode by setting INIT bit */
434	cr1 = readl(port->membase + LINCR1);
435	cr1 |= LINFLEXD_LINCR1_INIT;
436	writel(cr1, port->membase + LINCR1);
437
438	/* wait for init mode entry */
439	while ((readl(port->membase + LINSR)
440		& LINFLEXD_LINSR_LINS_MASK)
441		!= LINFLEXD_LINSR_LINS_INITMODE)
442		;
443
444	/*
445	 * only support CS8 and CS7, and for CS7 must enable PE.
446	 * supported mode:
447	 *	- (7,e/o,1)
448	 *	- (8,n,1)
449	 *	- (8,e/o,1)
450	 */
451	/* enter the UART into configuration mode */
452
453	while ((termios->c_cflag & CSIZE) != CS8 &&
454	       (termios->c_cflag & CSIZE) != CS7) {
455		termios->c_cflag &= ~CSIZE;
456		termios->c_cflag |= old_csize;
457		old_csize = CS8;
458	}
459
460	if ((termios->c_cflag & CSIZE) == CS7) {
461		/* Word length: WL1WL0:00 */
462		cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0;
463	}
464
465	if ((termios->c_cflag & CSIZE) == CS8) {
466		/* Word length: WL1WL0:01 */
467		cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1;
468	}
469
470	if (termios->c_cflag & CMSPAR) {
471		if ((termios->c_cflag & CSIZE) != CS8) {
472			termios->c_cflag &= ~CSIZE;
473			termios->c_cflag |= CS8;
474		}
475		/* has a space/sticky bit */
476		cr |= LINFLEXD_UARTCR_WL0;
477	}
478
479	if (termios->c_cflag & CSTOPB)
480		termios->c_cflag &= ~CSTOPB;
481
482	/* parity must be enabled when CS7 to match 8-bits format */
483	if ((termios->c_cflag & CSIZE) == CS7)
484		termios->c_cflag |= PARENB;
485
486	if ((termios->c_cflag & PARENB)) {
487		cr |= LINFLEXD_UARTCR_PCE;
488		if (termios->c_cflag & PARODD)
489			cr = (cr | LINFLEXD_UARTCR_PC0) &
490			     (~LINFLEXD_UARTCR_PC1);
491		else
492			cr = cr & (~LINFLEXD_UARTCR_PC1 &
493				   ~LINFLEXD_UARTCR_PC0);
494	} else {
495		cr &= ~LINFLEXD_UARTCR_PCE;
496	}
497
498	spin_lock_irqsave(&port->lock, flags);
499
500	port->read_status_mask = 0;
501
502	if (termios->c_iflag & INPCK)
503		port->read_status_mask |=	(LINFLEXD_UARTSR_FEF |
504						 LINFLEXD_UARTSR_PE0 |
505						 LINFLEXD_UARTSR_PE1 |
506						 LINFLEXD_UARTSR_PE2 |
507						 LINFLEXD_UARTSR_PE3);
508	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
509		port->read_status_mask |= LINFLEXD_UARTSR_FEF;
510
511	/* characters to ignore */
512	port->ignore_status_mask = 0;
513	if (termios->c_iflag & IGNPAR)
514		port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
515	if (termios->c_iflag & IGNBRK) {
516		port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
517		/*
518		 * if we're ignoring parity and break indicators,
519		 * ignore overruns too (for real raw support).
520		 */
521		if (termios->c_iflag & IGNPAR)
522			port->ignore_status_mask |= LINFLEXD_UARTSR_BOF;
523	}
524
525	writel(cr, port->membase + UARTCR);
526
527	cr1 &= ~(LINFLEXD_LINCR1_INIT);
528
529	writel(cr1, port->membase + LINCR1);
530
531	spin_unlock_irqrestore(&port->lock, flags);
532}
533
534static const char *linflex_type(struct uart_port *port)
535{
536	return "FSL_LINFLEX";
537}
538
539static void linflex_release_port(struct uart_port *port)
540{
541	/* nothing to do */
542}
543
544static int linflex_request_port(struct uart_port *port)
545{
546	return 0;
547}
548
549/* configure/auto-configure the port */
550static void linflex_config_port(struct uart_port *port, int flags)
551{
552	if (flags & UART_CONFIG_TYPE)
553		port->type = PORT_LINFLEXUART;
554}
555
556static const struct uart_ops linflex_pops = {
557	.tx_empty	= linflex_tx_empty,
558	.set_mctrl	= linflex_set_mctrl,
559	.get_mctrl	= linflex_get_mctrl,
560	.stop_tx	= linflex_stop_tx,
561	.start_tx	= linflex_start_tx,
562	.stop_rx	= linflex_stop_rx,
563	.break_ctl	= linflex_break_ctl,
564	.startup	= linflex_startup,
565	.shutdown	= linflex_shutdown,
566	.set_termios	= linflex_set_termios,
567	.type		= linflex_type,
568	.request_port	= linflex_request_port,
569	.release_port	= linflex_release_port,
570	.config_port	= linflex_config_port,
571};
572
573static struct uart_port *linflex_ports[UART_NR];
574
575#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
576static void linflex_console_putchar(struct uart_port *port, int ch)
577{
578	unsigned long cr;
579
580	cr = readl(port->membase + UARTCR);
581
582	writeb(ch, port->membase + BDRL);
583
584	if (!(cr & LINFLEXD_UARTCR_TFBM))
585		while ((readl(port->membase + UARTSR) &
586					LINFLEXD_UARTSR_DTFTFF)
587				!= LINFLEXD_UARTSR_DTFTFF)
588			;
589	else
590		while (readl(port->membase + UARTSR) &
591					LINFLEXD_UARTSR_DTFTFF)
592			;
593
594	if (!(cr & LINFLEXD_UARTCR_TFBM)) {
595		writel((readl(port->membase + UARTSR) |
596					LINFLEXD_UARTSR_DTFTFF),
597					port->membase + UARTSR);
598	}
599}
600
601static void linflex_earlycon_putchar(struct uart_port *port, int ch)
602{
603	unsigned long flags;
604	char *ret;
605
606	if (!linflex_earlycon_same_instance) {
607		linflex_console_putchar(port, ch);
608		return;
609	}
610
611	spin_lock_irqsave(&init_lock, flags);
612	if (!during_init)
613		goto outside_init;
614
615	if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT)
616		goto init_release;
617
618	if (!earlycon_buf.cap) {
619		earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP,
620					       GFP_ATOMIC);
621		earlycon_buf.cap = earlycon_buf.content ?
622				   EARLYCON_BUFFER_INITIAL_CAP : 0;
623	} else if (earlycon_buf.len == earlycon_buf.cap) {
624		ret = krealloc(earlycon_buf.content, earlycon_buf.cap << 1,
625			       GFP_ATOMIC);
626		if (ret) {
627			earlycon_buf.content = ret;
628			earlycon_buf.cap <<= 1;
629		}
630	}
631
632	if (earlycon_buf.len < earlycon_buf.cap)
633		earlycon_buf.content[earlycon_buf.len++] = ch;
634
635	goto init_release;
636
637outside_init:
638	linflex_console_putchar(port, ch);
639init_release:
640	spin_unlock_irqrestore(&init_lock, flags);
641}
642
643static void linflex_string_write(struct uart_port *sport, const char *s,
644				 unsigned int count)
645{
646	unsigned long cr, ier = 0;
647
648	ier = readl(sport->membase + LINIER);
649	linflex_stop_tx(sport);
650
651	cr = readl(sport->membase + UARTCR);
652	cr |= (LINFLEXD_UARTCR_TXEN);
653	writel(cr, sport->membase + UARTCR);
654
655	uart_console_write(sport, s, count, linflex_console_putchar);
656
657	writel(ier, sport->membase + LINIER);
658}
659
660static void
661linflex_console_write(struct console *co, const char *s, unsigned int count)
662{
663	struct uart_port *sport = linflex_ports[co->index];
664	unsigned long flags;
665	int locked = 1;
666
667	if (sport->sysrq)
668		locked = 0;
669	else if (oops_in_progress)
670		locked = spin_trylock_irqsave(&sport->lock, flags);
671	else
672		spin_lock_irqsave(&sport->lock, flags);
673
674	linflex_string_write(sport, s, count);
675
676	if (locked)
677		spin_unlock_irqrestore(&sport->lock, flags);
678}
679
680/*
681 * if the port was already initialised (eg, by a boot loader),
682 * try to determine the current setup.
683 */
684static void __init
685linflex_console_get_options(struct uart_port *sport, int *parity, int *bits)
686{
687	unsigned long cr;
688
689	cr = readl(sport->membase + UARTCR);
690	cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN;
691
692	if (!cr)
693		return;
694
695	/* ok, the port was enabled */
696
697	*parity = 'n';
698	if (cr & LINFLEXD_UARTCR_PCE) {
699		if (cr & LINFLEXD_UARTCR_PC0)
700			*parity = 'o';
701		else
702			*parity = 'e';
703	}
704
705	if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) {
706		if (cr & LINFLEXD_UARTCR_PCE)
707			*bits = 9;
708		else
709			*bits = 8;
710	}
711}
712
713static int __init linflex_console_setup(struct console *co, char *options)
714{
715	struct uart_port *sport;
716	int baud = 115200;
717	int bits = 8;
718	int parity = 'n';
719	int flow = 'n';
720	int ret;
721	int i;
722	unsigned long flags;
723	/*
724	 * check whether an invalid uart number has been specified, and
725	 * if so, search for the first available port that does have
726	 * console support.
727	 */
728	if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports))
729		co->index = 0;
730
731	sport = linflex_ports[co->index];
732	if (!sport)
733		return -ENODEV;
734
735	if (options)
736		uart_parse_options(options, &baud, &parity, &bits, &flow);
737	else
738		linflex_console_get_options(sport, &parity, &bits);
739
740	if (earlycon_port && sport->mapbase == earlycon_port->mapbase) {
741		linflex_earlycon_same_instance = true;
742
743		spin_lock_irqsave(&init_lock, flags);
744		during_init = true;
745		spin_unlock_irqrestore(&init_lock, flags);
746
747		/* Workaround for character loss or output of many invalid
748		 * characters, when INIT mode is entered shortly after a
749		 * character has just been printed.
750		 */
751		udelay(PREINIT_DELAY);
752	}
753
754	linflex_setup_watermark(sport);
755
756	ret = uart_set_options(sport, co, baud, parity, bits, flow);
757
758	if (!linflex_earlycon_same_instance)
759		goto done;
760
761	spin_lock_irqsave(&init_lock, flags);
762
763	/* Emptying buffer */
764	if (earlycon_buf.len) {
765		for (i = 0; i < earlycon_buf.len; i++)
766			linflex_console_putchar(earlycon_port,
767				earlycon_buf.content[i]);
768
769		kfree(earlycon_buf.content);
770		earlycon_buf.len = 0;
771	}
772
773	during_init = false;
774	spin_unlock_irqrestore(&init_lock, flags);
775
776done:
777	return ret;
778}
779
780static struct uart_driver linflex_reg;
781static struct console linflex_console = {
782	.name		= DEV_NAME,
783	.write		= linflex_console_write,
784	.device		= uart_console_device,
785	.setup		= linflex_console_setup,
786	.flags		= CON_PRINTBUFFER,
787	.index		= -1,
788	.data		= &linflex_reg,
789};
790
791static void linflex_earlycon_write(struct console *con, const char *s,
792				   unsigned int n)
793{
794	struct earlycon_device *dev = con->data;
795
796	uart_console_write(&dev->port, s, n, linflex_earlycon_putchar);
797}
798
799static int __init linflex_early_console_setup(struct earlycon_device *device,
800					      const char *options)
801{
802	if (!device->port.membase)
803		return -ENODEV;
804
805	device->con->write = linflex_earlycon_write;
806	earlycon_port = &device->port;
807
808	return 0;
809}
810
811OF_EARLYCON_DECLARE(linflex, "fsl,s32v234-linflexuart",
812		    linflex_early_console_setup);
813
814#define LINFLEX_CONSOLE	(&linflex_console)
815#else
816#define LINFLEX_CONSOLE	NULL
817#endif
818
819static struct uart_driver linflex_reg = {
820	.owner		= THIS_MODULE,
821	.driver_name	= DRIVER_NAME,
822	.dev_name	= DEV_NAME,
823	.nr		= ARRAY_SIZE(linflex_ports),
824	.cons		= LINFLEX_CONSOLE,
825};
826
827static int linflex_probe(struct platform_device *pdev)
828{
829	struct device_node *np = pdev->dev.of_node;
830	struct uart_port *sport;
831	struct resource *res;
832	int ret;
833
834	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
835	if (!sport)
836		return -ENOMEM;
837
838	ret = of_alias_get_id(np, "serial");
839	if (ret < 0) {
840		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
841		return ret;
842	}
843	if (ret >= UART_NR) {
844		dev_err(&pdev->dev, "driver limited to %d serial ports\n",
845			UART_NR);
846		return -ENOMEM;
847	}
848
849	sport->line = ret;
850
851	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
852	if (!res)
853		return -ENODEV;
854
855	sport->mapbase = res->start;
856	sport->membase = devm_ioremap_resource(&pdev->dev, res);
857	if (IS_ERR(sport->membase))
858		return PTR_ERR(sport->membase);
859
860	sport->dev = &pdev->dev;
861	sport->type = PORT_LINFLEXUART;
862	sport->iotype = UPIO_MEM;
863	sport->irq = platform_get_irq(pdev, 0);
864	sport->ops = &linflex_pops;
865	sport->flags = UPF_BOOT_AUTOCONF;
866
867	linflex_ports[sport->line] = sport;
868
869	platform_set_drvdata(pdev, sport);
870
871	ret = uart_add_one_port(&linflex_reg, sport);
872	if (ret)
873		return ret;
874
875	return 0;
876}
877
878static int linflex_remove(struct platform_device *pdev)
879{
880	struct uart_port *sport = platform_get_drvdata(pdev);
881
882	uart_remove_one_port(&linflex_reg, sport);
883
884	return 0;
885}
886
887#ifdef CONFIG_PM_SLEEP
888static int linflex_suspend(struct device *dev)
889{
890	struct uart_port *sport = dev_get_drvdata(dev);
891
892	uart_suspend_port(&linflex_reg, sport);
893
894	return 0;
895}
896
897static int linflex_resume(struct device *dev)
898{
899	struct uart_port *sport = dev_get_drvdata(dev);
900
901	uart_resume_port(&linflex_reg, sport);
902
903	return 0;
904}
905#endif
906
907static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
908
909static struct platform_driver linflex_driver = {
910	.probe		= linflex_probe,
911	.remove		= linflex_remove,
912	.driver		= {
913		.name	= DRIVER_NAME,
914		.of_match_table	= linflex_dt_ids,
915		.pm	= &linflex_pm_ops,
916	},
917};
918
919static int __init linflex_serial_init(void)
920{
921	int ret;
922
923	ret = uart_register_driver(&linflex_reg);
924	if (ret)
925		return ret;
926
927	ret = platform_driver_register(&linflex_driver);
928	if (ret)
929		uart_unregister_driver(&linflex_reg);
930
931	return ret;
932}
933
934static void __exit linflex_serial_exit(void)
935{
936	platform_driver_unregister(&linflex_driver);
937	uart_unregister_driver(&linflex_reg);
938}
939
940module_init(linflex_serial_init);
941module_exit(linflex_serial_exit);
942
943MODULE_DESCRIPTION("Freescale linflex serial port driver");
944MODULE_LICENSE("GPL v2");