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v6.8
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * High Speed Serial Ports on NXP LPC32xx SoC
  4 *
  5 * Authors: Kevin Wells <kevin.wells@nxp.com>
  6 *          Roland Stigge <stigge@antcom.de>
  7 *
  8 * Copyright (C) 2010 NXP Semiconductors
  9 * Copyright (C) 2012 Roland Stigge
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/ioport.h>
 14#include <linux/init.h>
 15#include <linux/console.h>
 16#include <linux/sysrq.h>
 17#include <linux/tty.h>
 18#include <linux/tty_flip.h>
 19#include <linux/serial_core.h>
 20#include <linux/serial.h>
 21#include <linux/platform_device.h>
 22#include <linux/delay.h>
 23#include <linux/nmi.h>
 24#include <linux/io.h>
 25#include <linux/irq.h>
 
 26#include <linux/of.h>
 27#include <linux/sizes.h>
 28#include <linux/soc/nxp/lpc32xx-misc.h>
 29
 30/*
 31 * High Speed UART register offsets
 32 */
 33#define LPC32XX_HSUART_FIFO(x)			((x) + 0x00)
 34#define LPC32XX_HSUART_LEVEL(x)			((x) + 0x04)
 35#define LPC32XX_HSUART_IIR(x)			((x) + 0x08)
 36#define LPC32XX_HSUART_CTRL(x)			((x) + 0x0C)
 37#define LPC32XX_HSUART_RATE(x)			((x) + 0x10)
 38
 39#define LPC32XX_HSU_BREAK_DATA			(1 << 10)
 40#define LPC32XX_HSU_ERROR_DATA			(1 << 9)
 41#define LPC32XX_HSU_RX_EMPTY			(1 << 8)
 42
 43#define LPC32XX_HSU_TX_LEV(n)			(((n) >> 8) & 0xFF)
 44#define LPC32XX_HSU_RX_LEV(n)			((n) & 0xFF)
 45
 46#define LPC32XX_HSU_TX_INT_SET			(1 << 6)
 47#define LPC32XX_HSU_RX_OE_INT			(1 << 5)
 48#define LPC32XX_HSU_BRK_INT			(1 << 4)
 49#define LPC32XX_HSU_FE_INT			(1 << 3)
 50#define LPC32XX_HSU_RX_TIMEOUT_INT		(1 << 2)
 51#define LPC32XX_HSU_RX_TRIG_INT			(1 << 1)
 52#define LPC32XX_HSU_TX_INT			(1 << 0)
 53
 54#define LPC32XX_HSU_HRTS_INV			(1 << 21)
 55#define LPC32XX_HSU_HRTS_TRIG_8B		(0x0 << 19)
 56#define LPC32XX_HSU_HRTS_TRIG_16B		(0x1 << 19)
 57#define LPC32XX_HSU_HRTS_TRIG_32B		(0x2 << 19)
 58#define LPC32XX_HSU_HRTS_TRIG_48B		(0x3 << 19)
 59#define LPC32XX_HSU_HRTS_EN			(1 << 18)
 60#define LPC32XX_HSU_TMO_DISABLED		(0x0 << 16)
 61#define LPC32XX_HSU_TMO_INACT_4B		(0x1 << 16)
 62#define LPC32XX_HSU_TMO_INACT_8B		(0x2 << 16)
 63#define LPC32XX_HSU_TMO_INACT_16B		(0x3 << 16)
 64#define LPC32XX_HSU_HCTS_INV			(1 << 15)
 65#define LPC32XX_HSU_HCTS_EN			(1 << 14)
 66#define LPC32XX_HSU_OFFSET(n)			((n) << 9)
 67#define LPC32XX_HSU_BREAK			(1 << 8)
 68#define LPC32XX_HSU_ERR_INT_EN			(1 << 7)
 69#define LPC32XX_HSU_RX_INT_EN			(1 << 6)
 70#define LPC32XX_HSU_TX_INT_EN			(1 << 5)
 71#define LPC32XX_HSU_RX_TL1B			(0x0 << 2)
 72#define LPC32XX_HSU_RX_TL4B			(0x1 << 2)
 73#define LPC32XX_HSU_RX_TL8B			(0x2 << 2)
 74#define LPC32XX_HSU_RX_TL16B			(0x3 << 2)
 75#define LPC32XX_HSU_RX_TL32B			(0x4 << 2)
 76#define LPC32XX_HSU_RX_TL48B			(0x5 << 2)
 77#define LPC32XX_HSU_TX_TLEMPTY			(0x0 << 0)
 78#define LPC32XX_HSU_TX_TL0B			(0x0 << 0)
 79#define LPC32XX_HSU_TX_TL4B			(0x1 << 0)
 80#define LPC32XX_HSU_TX_TL8B			(0x2 << 0)
 81#define LPC32XX_HSU_TX_TL16B			(0x3 << 0)
 82
 83#define LPC32XX_MAIN_OSC_FREQ			13000000
 84
 85#define MODNAME "lpc32xx_hsuart"
 86
 87struct lpc32xx_hsuart_port {
 88	struct uart_port port;
 89};
 90
 91#define FIFO_READ_LIMIT 128
 92#define MAX_PORTS 3
 93#define LPC32XX_TTY_NAME "ttyTX"
 94static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
 95
 96#ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
 97static void wait_for_xmit_empty(struct uart_port *port)
 98{
 99	unsigned int timeout = 10000;
100
101	do {
102		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
103							port->membase))) == 0)
104			break;
105		if (--timeout == 0)
106			break;
107		udelay(1);
108	} while (1);
109}
110
111static void wait_for_xmit_ready(struct uart_port *port)
112{
113	unsigned int timeout = 10000;
114
115	while (1) {
116		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
117							port->membase))) < 32)
118			break;
119		if (--timeout == 0)
120			break;
121		udelay(1);
122	}
123}
124
125static void lpc32xx_hsuart_console_putchar(struct uart_port *port, unsigned char ch)
126{
127	wait_for_xmit_ready(port);
128	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
129}
130
131static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
132					 unsigned int count)
133{
134	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
135	unsigned long flags;
136	int locked = 1;
137
138	touch_nmi_watchdog();
139	local_irq_save(flags);
140	if (up->port.sysrq)
141		locked = 0;
142	else if (oops_in_progress)
143		locked = uart_port_trylock(&up->port);
144	else
145		uart_port_lock(&up->port);
146
147	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
148	wait_for_xmit_empty(&up->port);
149
150	if (locked)
151		uart_port_unlock(&up->port);
152	local_irq_restore(flags);
153}
154
155static int __init lpc32xx_hsuart_console_setup(struct console *co,
156					       char *options)
157{
158	struct uart_port *port;
159	int baud = 115200;
160	int bits = 8;
161	int parity = 'n';
162	int flow = 'n';
163
164	if (co->index >= MAX_PORTS)
165		co->index = 0;
166
167	port = &lpc32xx_hs_ports[co->index].port;
168	if (!port->membase)
169		return -ENODEV;
170
171	if (options)
172		uart_parse_options(options, &baud, &parity, &bits, &flow);
173
174	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
175
176	return uart_set_options(port, co, baud, parity, bits, flow);
177}
178
179static struct uart_driver lpc32xx_hsuart_reg;
180static struct console lpc32xx_hsuart_console = {
181	.name		= LPC32XX_TTY_NAME,
182	.write		= lpc32xx_hsuart_console_write,
183	.device		= uart_console_device,
184	.setup		= lpc32xx_hsuart_console_setup,
185	.flags		= CON_PRINTBUFFER,
186	.index		= -1,
187	.data		= &lpc32xx_hsuart_reg,
188};
189
190static int __init lpc32xx_hsuart_console_init(void)
191{
192	register_console(&lpc32xx_hsuart_console);
193	return 0;
194}
195console_initcall(lpc32xx_hsuart_console_init);
196
197#define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
198#else
199#define LPC32XX_HSUART_CONSOLE NULL
200#endif
201
202static struct uart_driver lpc32xx_hs_reg = {
203	.owner		= THIS_MODULE,
204	.driver_name	= MODNAME,
205	.dev_name	= LPC32XX_TTY_NAME,
206	.nr		= MAX_PORTS,
207	.cons		= LPC32XX_HSUART_CONSOLE,
208};
209static int uarts_registered;
210
211static unsigned int __serial_get_clock_div(unsigned long uartclk,
212					   unsigned long rate)
213{
214	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
215	u32 rate_diff;
216
217	/* Find the closest divider to get the desired clock rate */
218	div = uartclk / rate;
219	goodrate = hsu_rate = (div / 14) - 1;
220	if (hsu_rate != 0)
221		hsu_rate--;
222
223	/* Tweak divider */
224	l_hsu_rate = hsu_rate + 3;
225	rate_diff = 0xFFFFFFFF;
226
227	while (hsu_rate < l_hsu_rate) {
228		comprate = uartclk / ((hsu_rate + 1) * 14);
229		if (abs(comprate - rate) < rate_diff) {
230			goodrate = hsu_rate;
231			rate_diff = abs(comprate - rate);
232		}
233
234		hsu_rate++;
235	}
236	if (hsu_rate > 0xFF)
237		hsu_rate = 0xFF;
238
239	return goodrate;
240}
241
242static void __serial_uart_flush(struct uart_port *port)
243{
 
244	int cnt = 0;
245
246	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
247	       (cnt++ < FIFO_READ_LIMIT))
248		readl(LPC32XX_HSUART_FIFO(port->membase));
249}
250
251static void __serial_lpc32xx_rx(struct uart_port *port)
252{
253	struct tty_port *tport = &port->state->port;
254	unsigned int tmp, flag;
255
256	/* Read data from FIFO and push into terminal */
257	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
258	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
259		flag = TTY_NORMAL;
260		port->icount.rx++;
261
262		if (tmp & LPC32XX_HSU_ERROR_DATA) {
263			/* Framing error */
264			writel(LPC32XX_HSU_FE_INT,
265			       LPC32XX_HSUART_IIR(port->membase));
266			port->icount.frame++;
267			flag = TTY_FRAME;
268			tty_insert_flip_char(tport, 0, TTY_FRAME);
269		}
270
271		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
272
273		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
274	}
275
 
276	tty_flip_buffer_push(tport);
 
277}
278
279static bool serial_lpc32xx_tx_ready(struct uart_port *port)
280{
281	u32 level = readl(LPC32XX_HSUART_LEVEL(port->membase));
 
282
283	return LPC32XX_HSU_TX_LEV(level) < 64;
284}
 
 
 
 
285
286static void __serial_lpc32xx_tx(struct uart_port *port)
287{
288	u8 ch;
 
 
 
 
 
 
 
 
 
 
 
 
 
289
290	uart_port_tx(port, ch,
291		serial_lpc32xx_tx_ready(port),
292		writel(ch, LPC32XX_HSUART_FIFO(port->membase)));
 
 
 
293}
294
295static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
296{
297	struct uart_port *port = dev_id;
298	struct tty_port *tport = &port->state->port;
299	u32 status;
300
301	uart_port_lock(port);
302
303	/* Read UART status and clear latched interrupts */
304	status = readl(LPC32XX_HSUART_IIR(port->membase));
305
306	if (status & LPC32XX_HSU_BRK_INT) {
307		/* Break received */
308		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
309		port->icount.brk++;
310		uart_handle_break(port);
311	}
312
313	/* Framing error */
314	if (status & LPC32XX_HSU_FE_INT)
315		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
316
317	if (status & LPC32XX_HSU_RX_OE_INT) {
318		/* Receive FIFO overrun */
319		writel(LPC32XX_HSU_RX_OE_INT,
320		       LPC32XX_HSUART_IIR(port->membase));
321		port->icount.overrun++;
322		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
323		tty_flip_buffer_push(tport);
324	}
325
326	/* Data received? */
327	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
328		__serial_lpc32xx_rx(port);
329
330	/* Transmit data request? */
331	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
332		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
333		__serial_lpc32xx_tx(port);
334	}
335
336	uart_port_unlock(port);
337
338	return IRQ_HANDLED;
339}
340
341/* port->lock is not held.  */
342static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
343{
344	unsigned int ret = 0;
345
346	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
347		ret = TIOCSER_TEMT;
348
349	return ret;
350}
351
352/* port->lock held by caller.  */
353static void serial_lpc32xx_set_mctrl(struct uart_port *port,
354				     unsigned int mctrl)
355{
356	/* No signals are supported on HS UARTs */
357}
358
359/* port->lock is held by caller and interrupts are disabled.  */
360static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
361{
362	/* No signals are supported on HS UARTs */
363	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
364}
365
366/* port->lock held by caller.  */
367static void serial_lpc32xx_stop_tx(struct uart_port *port)
368{
369	u32 tmp;
370
371	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
372	tmp &= ~LPC32XX_HSU_TX_INT_EN;
373	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
374}
375
376/* port->lock held by caller.  */
377static void serial_lpc32xx_start_tx(struct uart_port *port)
378{
379	u32 tmp;
380
381	__serial_lpc32xx_tx(port);
382	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
383	tmp |= LPC32XX_HSU_TX_INT_EN;
384	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
385}
386
387/* port->lock held by caller.  */
388static void serial_lpc32xx_stop_rx(struct uart_port *port)
389{
390	u32 tmp;
391
392	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
393	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
394	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
395
396	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
397		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
398}
399
400/* port->lock is not held.  */
401static void serial_lpc32xx_break_ctl(struct uart_port *port,
402				     int break_state)
403{
404	unsigned long flags;
405	u32 tmp;
406
407	uart_port_lock_irqsave(port, &flags);
408	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
409	if (break_state != 0)
410		tmp |= LPC32XX_HSU_BREAK;
411	else
412		tmp &= ~LPC32XX_HSU_BREAK;
413	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
414	uart_port_unlock_irqrestore(port, flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
415}
416
417/* port->lock is not held.  */
418static int serial_lpc32xx_startup(struct uart_port *port)
419{
420	int retval;
421	unsigned long flags;
422	u32 tmp;
423
424	uart_port_lock_irqsave(port, &flags);
425
426	__serial_uart_flush(port);
427
428	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
429		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
430	       LPC32XX_HSUART_IIR(port->membase));
431
432	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
433
434	/*
435	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
436	 * and default FIFO trigger levels
437	 */
438	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
439		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
440	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
441
442	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
443
444	uart_port_unlock_irqrestore(port, flags);
445
446	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
447			     0, MODNAME, port);
448	if (!retval)
449		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
450		       LPC32XX_HSUART_CTRL(port->membase));
451
452	return retval;
453}
454
455/* port->lock is not held.  */
456static void serial_lpc32xx_shutdown(struct uart_port *port)
457{
458	u32 tmp;
459	unsigned long flags;
460
461	uart_port_lock_irqsave(port, &flags);
462
463	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
464		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
465	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
466
467	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
468
469	uart_port_unlock_irqrestore(port, flags);
470
471	free_irq(port->irq, port);
472}
473
474/* port->lock is not held.  */
475static void serial_lpc32xx_set_termios(struct uart_port *port,
476				       struct ktermios *termios,
477				       const struct ktermios *old)
478{
479	unsigned long flags;
480	unsigned int baud, quot;
481	u32 tmp;
482
483	/* Always 8-bit, no parity, 1 stop bit */
484	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
485	termios->c_cflag |= CS8;
486
487	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
488
489	baud = uart_get_baud_rate(port, termios, old, 0,
490				  port->uartclk / 14);
491
492	quot = __serial_get_clock_div(port->uartclk, baud);
493
494	uart_port_lock_irqsave(port, &flags);
495
496	/* Ignore characters? */
497	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
498	if ((termios->c_cflag & CREAD) == 0)
499		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
500	else
501		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
502	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
503
504	writel(quot, LPC32XX_HSUART_RATE(port->membase));
505
506	uart_update_timeout(port, termios->c_cflag, baud);
507
508	uart_port_unlock_irqrestore(port, flags);
509
510	/* Don't rewrite B0 */
511	if (tty_termios_baud_rate(termios))
512		tty_termios_encode_baud_rate(termios, baud, baud);
513}
514
515static const char *serial_lpc32xx_type(struct uart_port *port)
516{
517	return MODNAME;
518}
519
520static void serial_lpc32xx_release_port(struct uart_port *port)
521{
522	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
523		if (port->flags & UPF_IOREMAP) {
524			iounmap(port->membase);
525			port->membase = NULL;
526		}
527
528		release_mem_region(port->mapbase, SZ_4K);
529	}
530}
531
532static int serial_lpc32xx_request_port(struct uart_port *port)
533{
534	int ret = -ENODEV;
535
536	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
537		ret = 0;
538
539		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
540			ret = -EBUSY;
541		else if (port->flags & UPF_IOREMAP) {
542			port->membase = ioremap(port->mapbase, SZ_4K);
543			if (!port->membase) {
544				release_mem_region(port->mapbase, SZ_4K);
545				ret = -ENOMEM;
546			}
547		}
548	}
549
550	return ret;
551}
552
553static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
554{
555	int ret;
556
557	ret = serial_lpc32xx_request_port(port);
558	if (ret < 0)
559		return;
560	port->type = PORT_UART00;
561	port->fifosize = 64;
562
563	__serial_uart_flush(port);
564
565	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
566		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
567	       LPC32XX_HSUART_IIR(port->membase));
568
569	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
570
571	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
572	   and default FIFO trigger levels */
573	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
574	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
575	       LPC32XX_HSUART_CTRL(port->membase));
576}
577
578static int serial_lpc32xx_verify_port(struct uart_port *port,
579				      struct serial_struct *ser)
580{
581	int ret = 0;
582
583	if (ser->type != PORT_UART00)
584		ret = -EINVAL;
585
586	return ret;
587}
588
589static const struct uart_ops serial_lpc32xx_pops = {
590	.tx_empty	= serial_lpc32xx_tx_empty,
591	.set_mctrl	= serial_lpc32xx_set_mctrl,
592	.get_mctrl	= serial_lpc32xx_get_mctrl,
593	.stop_tx	= serial_lpc32xx_stop_tx,
594	.start_tx	= serial_lpc32xx_start_tx,
595	.stop_rx	= serial_lpc32xx_stop_rx,
596	.break_ctl	= serial_lpc32xx_break_ctl,
597	.startup	= serial_lpc32xx_startup,
598	.shutdown	= serial_lpc32xx_shutdown,
599	.set_termios	= serial_lpc32xx_set_termios,
600	.type		= serial_lpc32xx_type,
601	.release_port	= serial_lpc32xx_release_port,
602	.request_port	= serial_lpc32xx_request_port,
603	.config_port	= serial_lpc32xx_config_port,
604	.verify_port	= serial_lpc32xx_verify_port,
605};
606
607/*
608 * Register a set of serial devices attached to a platform device
609 */
610static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
611{
612	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
613	int ret = 0;
614	struct resource *res;
615
616	if (uarts_registered >= MAX_PORTS) {
617		dev_err(&pdev->dev,
618			"Error: Number of possible ports exceeded (%d)!\n",
619			uarts_registered + 1);
620		return -ENXIO;
621	}
622
623	memset(p, 0, sizeof(*p));
624
625	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
626	if (!res) {
627		dev_err(&pdev->dev,
628			"Error getting mem resource for HS UART port %d\n",
629			uarts_registered);
630		return -ENXIO;
631	}
632	p->port.mapbase = res->start;
633	p->port.membase = NULL;
634
635	ret = platform_get_irq(pdev, 0);
636	if (ret < 0)
 
 
637		return ret;
 
638	p->port.irq = ret;
639
640	p->port.iotype = UPIO_MEM32;
641	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
642	p->port.regshift = 2;
643	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
644	p->port.dev = &pdev->dev;
645	p->port.ops = &serial_lpc32xx_pops;
646	p->port.line = uarts_registered++;
647	spin_lock_init(&p->port.lock);
648
649	/* send port to loopback mode by default */
650	lpc32xx_loopback_set(p->port.mapbase, 1);
651
652	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
653
654	platform_set_drvdata(pdev, p);
655
656	return ret;
657}
658
659/*
660 * Remove serial ports registered against a platform device.
661 */
662static void serial_hs_lpc32xx_remove(struct platform_device *pdev)
663{
664	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
665
666	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
 
 
667}
668
669
670#ifdef CONFIG_PM
671static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
672				     pm_message_t state)
673{
674	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
675
676	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
677
678	return 0;
679}
680
681static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
682{
683	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
684
685	uart_resume_port(&lpc32xx_hs_reg, &p->port);
686
687	return 0;
688}
689#else
690#define serial_hs_lpc32xx_suspend	NULL
691#define serial_hs_lpc32xx_resume	NULL
692#endif
693
694static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
695	{ .compatible = "nxp,lpc3220-hsuart" },
696	{ /* sentinel */ }
697};
698
699MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
700
701static struct platform_driver serial_hs_lpc32xx_driver = {
702	.probe		= serial_hs_lpc32xx_probe,
703	.remove_new	= serial_hs_lpc32xx_remove,
704	.suspend	= serial_hs_lpc32xx_suspend,
705	.resume		= serial_hs_lpc32xx_resume,
706	.driver		= {
707		.name	= MODNAME,
708		.of_match_table	= serial_hs_lpc32xx_dt_ids,
709	},
710};
711
712static int __init lpc32xx_hsuart_init(void)
713{
714	int ret;
715
716	ret = uart_register_driver(&lpc32xx_hs_reg);
717	if (ret)
718		return ret;
719
720	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
721	if (ret)
722		uart_unregister_driver(&lpc32xx_hs_reg);
723
724	return ret;
725}
726
727static void __exit lpc32xx_hsuart_exit(void)
728{
729	platform_driver_unregister(&serial_hs_lpc32xx_driver);
730	uart_unregister_driver(&lpc32xx_hs_reg);
731}
732
733module_init(lpc32xx_hsuart_init);
734module_exit(lpc32xx_hsuart_exit);
735
736MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
737MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
738MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
739MODULE_LICENSE("GPL");
v4.17
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * High Speed Serial Ports on NXP LPC32xx SoC
  4 *
  5 * Authors: Kevin Wells <kevin.wells@nxp.com>
  6 *          Roland Stigge <stigge@antcom.de>
  7 *
  8 * Copyright (C) 2010 NXP Semiconductors
  9 * Copyright (C) 2012 Roland Stigge
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/ioport.h>
 14#include <linux/init.h>
 15#include <linux/console.h>
 16#include <linux/sysrq.h>
 17#include <linux/tty.h>
 18#include <linux/tty_flip.h>
 19#include <linux/serial_core.h>
 20#include <linux/serial.h>
 21#include <linux/platform_device.h>
 22#include <linux/delay.h>
 23#include <linux/nmi.h>
 24#include <linux/io.h>
 25#include <linux/irq.h>
 26#include <linux/gpio.h>
 27#include <linux/of.h>
 28#include <mach/platform.h>
 29#include <mach/hardware.h>
 30
 31/*
 32 * High Speed UART register offsets
 33 */
 34#define LPC32XX_HSUART_FIFO(x)			((x) + 0x00)
 35#define LPC32XX_HSUART_LEVEL(x)			((x) + 0x04)
 36#define LPC32XX_HSUART_IIR(x)			((x) + 0x08)
 37#define LPC32XX_HSUART_CTRL(x)			((x) + 0x0C)
 38#define LPC32XX_HSUART_RATE(x)			((x) + 0x10)
 39
 40#define LPC32XX_HSU_BREAK_DATA			(1 << 10)
 41#define LPC32XX_HSU_ERROR_DATA			(1 << 9)
 42#define LPC32XX_HSU_RX_EMPTY			(1 << 8)
 43
 44#define LPC32XX_HSU_TX_LEV(n)			(((n) >> 8) & 0xFF)
 45#define LPC32XX_HSU_RX_LEV(n)			((n) & 0xFF)
 46
 47#define LPC32XX_HSU_TX_INT_SET			(1 << 6)
 48#define LPC32XX_HSU_RX_OE_INT			(1 << 5)
 49#define LPC32XX_HSU_BRK_INT			(1 << 4)
 50#define LPC32XX_HSU_FE_INT			(1 << 3)
 51#define LPC32XX_HSU_RX_TIMEOUT_INT		(1 << 2)
 52#define LPC32XX_HSU_RX_TRIG_INT			(1 << 1)
 53#define LPC32XX_HSU_TX_INT			(1 << 0)
 54
 55#define LPC32XX_HSU_HRTS_INV			(1 << 21)
 56#define LPC32XX_HSU_HRTS_TRIG_8B		(0x0 << 19)
 57#define LPC32XX_HSU_HRTS_TRIG_16B		(0x1 << 19)
 58#define LPC32XX_HSU_HRTS_TRIG_32B		(0x2 << 19)
 59#define LPC32XX_HSU_HRTS_TRIG_48B		(0x3 << 19)
 60#define LPC32XX_HSU_HRTS_EN			(1 << 18)
 61#define LPC32XX_HSU_TMO_DISABLED		(0x0 << 16)
 62#define LPC32XX_HSU_TMO_INACT_4B		(0x1 << 16)
 63#define LPC32XX_HSU_TMO_INACT_8B		(0x2 << 16)
 64#define LPC32XX_HSU_TMO_INACT_16B		(0x3 << 16)
 65#define LPC32XX_HSU_HCTS_INV			(1 << 15)
 66#define LPC32XX_HSU_HCTS_EN			(1 << 14)
 67#define LPC32XX_HSU_OFFSET(n)			((n) << 9)
 68#define LPC32XX_HSU_BREAK			(1 << 8)
 69#define LPC32XX_HSU_ERR_INT_EN			(1 << 7)
 70#define LPC32XX_HSU_RX_INT_EN			(1 << 6)
 71#define LPC32XX_HSU_TX_INT_EN			(1 << 5)
 72#define LPC32XX_HSU_RX_TL1B			(0x0 << 2)
 73#define LPC32XX_HSU_RX_TL4B			(0x1 << 2)
 74#define LPC32XX_HSU_RX_TL8B			(0x2 << 2)
 75#define LPC32XX_HSU_RX_TL16B			(0x3 << 2)
 76#define LPC32XX_HSU_RX_TL32B			(0x4 << 2)
 77#define LPC32XX_HSU_RX_TL48B			(0x5 << 2)
 78#define LPC32XX_HSU_TX_TLEMPTY			(0x0 << 0)
 79#define LPC32XX_HSU_TX_TL0B			(0x0 << 0)
 80#define LPC32XX_HSU_TX_TL4B			(0x1 << 0)
 81#define LPC32XX_HSU_TX_TL8B			(0x2 << 0)
 82#define LPC32XX_HSU_TX_TL16B			(0x3 << 0)
 83
 
 
 84#define MODNAME "lpc32xx_hsuart"
 85
 86struct lpc32xx_hsuart_port {
 87	struct uart_port port;
 88};
 89
 90#define FIFO_READ_LIMIT 128
 91#define MAX_PORTS 3
 92#define LPC32XX_TTY_NAME "ttyTX"
 93static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
 94
 95#ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
 96static void wait_for_xmit_empty(struct uart_port *port)
 97{
 98	unsigned int timeout = 10000;
 99
100	do {
101		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
102							port->membase))) == 0)
103			break;
104		if (--timeout == 0)
105			break;
106		udelay(1);
107	} while (1);
108}
109
110static void wait_for_xmit_ready(struct uart_port *port)
111{
112	unsigned int timeout = 10000;
113
114	while (1) {
115		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
116							port->membase))) < 32)
117			break;
118		if (--timeout == 0)
119			break;
120		udelay(1);
121	}
122}
123
124static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
125{
126	wait_for_xmit_ready(port);
127	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
128}
129
130static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
131					 unsigned int count)
132{
133	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
134	unsigned long flags;
135	int locked = 1;
136
137	touch_nmi_watchdog();
138	local_irq_save(flags);
139	if (up->port.sysrq)
140		locked = 0;
141	else if (oops_in_progress)
142		locked = spin_trylock(&up->port.lock);
143	else
144		spin_lock(&up->port.lock);
145
146	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
147	wait_for_xmit_empty(&up->port);
148
149	if (locked)
150		spin_unlock(&up->port.lock);
151	local_irq_restore(flags);
152}
153
154static int __init lpc32xx_hsuart_console_setup(struct console *co,
155					       char *options)
156{
157	struct uart_port *port;
158	int baud = 115200;
159	int bits = 8;
160	int parity = 'n';
161	int flow = 'n';
162
163	if (co->index >= MAX_PORTS)
164		co->index = 0;
165
166	port = &lpc32xx_hs_ports[co->index].port;
167	if (!port->membase)
168		return -ENODEV;
169
170	if (options)
171		uart_parse_options(options, &baud, &parity, &bits, &flow);
172
 
 
173	return uart_set_options(port, co, baud, parity, bits, flow);
174}
175
176static struct uart_driver lpc32xx_hsuart_reg;
177static struct console lpc32xx_hsuart_console = {
178	.name		= LPC32XX_TTY_NAME,
179	.write		= lpc32xx_hsuart_console_write,
180	.device		= uart_console_device,
181	.setup		= lpc32xx_hsuart_console_setup,
182	.flags		= CON_PRINTBUFFER,
183	.index		= -1,
184	.data		= &lpc32xx_hsuart_reg,
185};
186
187static int __init lpc32xx_hsuart_console_init(void)
188{
189	register_console(&lpc32xx_hsuart_console);
190	return 0;
191}
192console_initcall(lpc32xx_hsuart_console_init);
193
194#define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
195#else
196#define LPC32XX_HSUART_CONSOLE NULL
197#endif
198
199static struct uart_driver lpc32xx_hs_reg = {
200	.owner		= THIS_MODULE,
201	.driver_name	= MODNAME,
202	.dev_name	= LPC32XX_TTY_NAME,
203	.nr		= MAX_PORTS,
204	.cons		= LPC32XX_HSUART_CONSOLE,
205};
206static int uarts_registered;
207
208static unsigned int __serial_get_clock_div(unsigned long uartclk,
209					   unsigned long rate)
210{
211	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
212	u32 rate_diff;
213
214	/* Find the closest divider to get the desired clock rate */
215	div = uartclk / rate;
216	goodrate = hsu_rate = (div / 14) - 1;
217	if (hsu_rate != 0)
218		hsu_rate--;
219
220	/* Tweak divider */
221	l_hsu_rate = hsu_rate + 3;
222	rate_diff = 0xFFFFFFFF;
223
224	while (hsu_rate < l_hsu_rate) {
225		comprate = uartclk / ((hsu_rate + 1) * 14);
226		if (abs(comprate - rate) < rate_diff) {
227			goodrate = hsu_rate;
228			rate_diff = abs(comprate - rate);
229		}
230
231		hsu_rate++;
232	}
233	if (hsu_rate > 0xFF)
234		hsu_rate = 0xFF;
235
236	return goodrate;
237}
238
239static void __serial_uart_flush(struct uart_port *port)
240{
241	u32 tmp;
242	int cnt = 0;
243
244	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
245	       (cnt++ < FIFO_READ_LIMIT))
246		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
247}
248
249static void __serial_lpc32xx_rx(struct uart_port *port)
250{
251	struct tty_port *tport = &port->state->port;
252	unsigned int tmp, flag;
253
254	/* Read data from FIFO and push into terminal */
255	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
256	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
257		flag = TTY_NORMAL;
258		port->icount.rx++;
259
260		if (tmp & LPC32XX_HSU_ERROR_DATA) {
261			/* Framing error */
262			writel(LPC32XX_HSU_FE_INT,
263			       LPC32XX_HSUART_IIR(port->membase));
264			port->icount.frame++;
265			flag = TTY_FRAME;
266			tty_insert_flip_char(tport, 0, TTY_FRAME);
267		}
268
269		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
270
271		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
272	}
273
274	spin_unlock(&port->lock);
275	tty_flip_buffer_push(tport);
276	spin_lock(&port->lock);
277}
278
279static void __serial_lpc32xx_tx(struct uart_port *port)
280{
281	struct circ_buf *xmit = &port->state->xmit;
282	unsigned int tmp;
283
284	if (port->x_char) {
285		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
286		port->icount.tx++;
287		port->x_char = 0;
288		return;
289	}
290
291	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
292		goto exit_tx;
293
294	/* Transfer data */
295	while (LPC32XX_HSU_TX_LEV(readl(
296		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
297		writel((u32) xmit->buf[xmit->tail],
298		       LPC32XX_HSUART_FIFO(port->membase));
299		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
300		port->icount.tx++;
301		if (uart_circ_empty(xmit))
302			break;
303	}
304
305	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
306		uart_write_wakeup(port);
307
308exit_tx:
309	if (uart_circ_empty(xmit)) {
310		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
311		tmp &= ~LPC32XX_HSU_TX_INT_EN;
312		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
313	}
314}
315
316static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
317{
318	struct uart_port *port = dev_id;
319	struct tty_port *tport = &port->state->port;
320	u32 status;
321
322	spin_lock(&port->lock);
323
324	/* Read UART status and clear latched interrupts */
325	status = readl(LPC32XX_HSUART_IIR(port->membase));
326
327	if (status & LPC32XX_HSU_BRK_INT) {
328		/* Break received */
329		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
330		port->icount.brk++;
331		uart_handle_break(port);
332	}
333
334	/* Framing error */
335	if (status & LPC32XX_HSU_FE_INT)
336		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
337
338	if (status & LPC32XX_HSU_RX_OE_INT) {
339		/* Receive FIFO overrun */
340		writel(LPC32XX_HSU_RX_OE_INT,
341		       LPC32XX_HSUART_IIR(port->membase));
342		port->icount.overrun++;
343		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
344		tty_schedule_flip(tport);
345	}
346
347	/* Data received? */
348	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
349		__serial_lpc32xx_rx(port);
350
351	/* Transmit data request? */
352	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
353		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
354		__serial_lpc32xx_tx(port);
355	}
356
357	spin_unlock(&port->lock);
358
359	return IRQ_HANDLED;
360}
361
362/* port->lock is not held.  */
363static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
364{
365	unsigned int ret = 0;
366
367	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
368		ret = TIOCSER_TEMT;
369
370	return ret;
371}
372
373/* port->lock held by caller.  */
374static void serial_lpc32xx_set_mctrl(struct uart_port *port,
375				     unsigned int mctrl)
376{
377	/* No signals are supported on HS UARTs */
378}
379
380/* port->lock is held by caller and interrupts are disabled.  */
381static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
382{
383	/* No signals are supported on HS UARTs */
384	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
385}
386
387/* port->lock held by caller.  */
388static void serial_lpc32xx_stop_tx(struct uart_port *port)
389{
390	u32 tmp;
391
392	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
393	tmp &= ~LPC32XX_HSU_TX_INT_EN;
394	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
395}
396
397/* port->lock held by caller.  */
398static void serial_lpc32xx_start_tx(struct uart_port *port)
399{
400	u32 tmp;
401
402	__serial_lpc32xx_tx(port);
403	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
404	tmp |= LPC32XX_HSU_TX_INT_EN;
405	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
406}
407
408/* port->lock held by caller.  */
409static void serial_lpc32xx_stop_rx(struct uart_port *port)
410{
411	u32 tmp;
412
413	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
414	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
415	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
416
417	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
418		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
419}
420
421/* port->lock is not held.  */
422static void serial_lpc32xx_break_ctl(struct uart_port *port,
423				     int break_state)
424{
425	unsigned long flags;
426	u32 tmp;
427
428	spin_lock_irqsave(&port->lock, flags);
429	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
430	if (break_state != 0)
431		tmp |= LPC32XX_HSU_BREAK;
432	else
433		tmp &= ~LPC32XX_HSU_BREAK;
434	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
435	spin_unlock_irqrestore(&port->lock, flags);
436}
437
438/* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
439static void lpc32xx_loopback_set(resource_size_t mapbase, int state)
440{
441	int bit;
442	u32 tmp;
443
444	switch (mapbase) {
445	case LPC32XX_HS_UART1_BASE:
446		bit = 0;
447		break;
448	case LPC32XX_HS_UART2_BASE:
449		bit = 1;
450		break;
451	case LPC32XX_HS_UART7_BASE:
452		bit = 6;
453		break;
454	default:
455		WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
456		return;
457	}
458
459	tmp = readl(LPC32XX_UARTCTL_CLOOP);
460	if (state)
461		tmp |= (1 << bit);
462	else
463		tmp &= ~(1 << bit);
464	writel(tmp, LPC32XX_UARTCTL_CLOOP);
465}
466
467/* port->lock is not held.  */
468static int serial_lpc32xx_startup(struct uart_port *port)
469{
470	int retval;
471	unsigned long flags;
472	u32 tmp;
473
474	spin_lock_irqsave(&port->lock, flags);
475
476	__serial_uart_flush(port);
477
478	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
479		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
480	       LPC32XX_HSUART_IIR(port->membase));
481
482	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
483
484	/*
485	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
486	 * and default FIFO trigger levels
487	 */
488	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
489		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
490	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
491
492	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
493
494	spin_unlock_irqrestore(&port->lock, flags);
495
496	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
497			     0, MODNAME, port);
498	if (!retval)
499		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
500		       LPC32XX_HSUART_CTRL(port->membase));
501
502	return retval;
503}
504
505/* port->lock is not held.  */
506static void serial_lpc32xx_shutdown(struct uart_port *port)
507{
508	u32 tmp;
509	unsigned long flags;
510
511	spin_lock_irqsave(&port->lock, flags);
512
513	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
514		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
515	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
516
517	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
518
519	spin_unlock_irqrestore(&port->lock, flags);
520
521	free_irq(port->irq, port);
522}
523
524/* port->lock is not held.  */
525static void serial_lpc32xx_set_termios(struct uart_port *port,
526				       struct ktermios *termios,
527				       struct ktermios *old)
528{
529	unsigned long flags;
530	unsigned int baud, quot;
531	u32 tmp;
532
533	/* Always 8-bit, no parity, 1 stop bit */
534	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
535	termios->c_cflag |= CS8;
536
537	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
538
539	baud = uart_get_baud_rate(port, termios, old, 0,
540				  port->uartclk / 14);
541
542	quot = __serial_get_clock_div(port->uartclk, baud);
543
544	spin_lock_irqsave(&port->lock, flags);
545
546	/* Ignore characters? */
547	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
548	if ((termios->c_cflag & CREAD) == 0)
549		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
550	else
551		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
552	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
553
554	writel(quot, LPC32XX_HSUART_RATE(port->membase));
555
556	uart_update_timeout(port, termios->c_cflag, baud);
557
558	spin_unlock_irqrestore(&port->lock, flags);
559
560	/* Don't rewrite B0 */
561	if (tty_termios_baud_rate(termios))
562		tty_termios_encode_baud_rate(termios, baud, baud);
563}
564
565static const char *serial_lpc32xx_type(struct uart_port *port)
566{
567	return MODNAME;
568}
569
570static void serial_lpc32xx_release_port(struct uart_port *port)
571{
572	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
573		if (port->flags & UPF_IOREMAP) {
574			iounmap(port->membase);
575			port->membase = NULL;
576		}
577
578		release_mem_region(port->mapbase, SZ_4K);
579	}
580}
581
582static int serial_lpc32xx_request_port(struct uart_port *port)
583{
584	int ret = -ENODEV;
585
586	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
587		ret = 0;
588
589		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
590			ret = -EBUSY;
591		else if (port->flags & UPF_IOREMAP) {
592			port->membase = ioremap(port->mapbase, SZ_4K);
593			if (!port->membase) {
594				release_mem_region(port->mapbase, SZ_4K);
595				ret = -ENOMEM;
596			}
597		}
598	}
599
600	return ret;
601}
602
603static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
604{
605	int ret;
606
607	ret = serial_lpc32xx_request_port(port);
608	if (ret < 0)
609		return;
610	port->type = PORT_UART00;
611	port->fifosize = 64;
612
613	__serial_uart_flush(port);
614
615	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
616		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
617	       LPC32XX_HSUART_IIR(port->membase));
618
619	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
620
621	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
622	   and default FIFO trigger levels */
623	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
624	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
625	       LPC32XX_HSUART_CTRL(port->membase));
626}
627
628static int serial_lpc32xx_verify_port(struct uart_port *port,
629				      struct serial_struct *ser)
630{
631	int ret = 0;
632
633	if (ser->type != PORT_UART00)
634		ret = -EINVAL;
635
636	return ret;
637}
638
639static const struct uart_ops serial_lpc32xx_pops = {
640	.tx_empty	= serial_lpc32xx_tx_empty,
641	.set_mctrl	= serial_lpc32xx_set_mctrl,
642	.get_mctrl	= serial_lpc32xx_get_mctrl,
643	.stop_tx	= serial_lpc32xx_stop_tx,
644	.start_tx	= serial_lpc32xx_start_tx,
645	.stop_rx	= serial_lpc32xx_stop_rx,
646	.break_ctl	= serial_lpc32xx_break_ctl,
647	.startup	= serial_lpc32xx_startup,
648	.shutdown	= serial_lpc32xx_shutdown,
649	.set_termios	= serial_lpc32xx_set_termios,
650	.type		= serial_lpc32xx_type,
651	.release_port	= serial_lpc32xx_release_port,
652	.request_port	= serial_lpc32xx_request_port,
653	.config_port	= serial_lpc32xx_config_port,
654	.verify_port	= serial_lpc32xx_verify_port,
655};
656
657/*
658 * Register a set of serial devices attached to a platform device
659 */
660static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
661{
662	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
663	int ret = 0;
664	struct resource *res;
665
666	if (uarts_registered >= MAX_PORTS) {
667		dev_err(&pdev->dev,
668			"Error: Number of possible ports exceeded (%d)!\n",
669			uarts_registered + 1);
670		return -ENXIO;
671	}
672
673	memset(p, 0, sizeof(*p));
674
675	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
676	if (!res) {
677		dev_err(&pdev->dev,
678			"Error getting mem resource for HS UART port %d\n",
679			uarts_registered);
680		return -ENXIO;
681	}
682	p->port.mapbase = res->start;
683	p->port.membase = NULL;
684
685	ret = platform_get_irq(pdev, 0);
686	if (ret < 0) {
687		dev_err(&pdev->dev, "Error getting irq for HS UART port %d\n",
688			uarts_registered);
689		return ret;
690	}
691	p->port.irq = ret;
692
693	p->port.iotype = UPIO_MEM32;
694	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
695	p->port.regshift = 2;
696	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
697	p->port.dev = &pdev->dev;
698	p->port.ops = &serial_lpc32xx_pops;
699	p->port.line = uarts_registered++;
700	spin_lock_init(&p->port.lock);
701
702	/* send port to loopback mode by default */
703	lpc32xx_loopback_set(p->port.mapbase, 1);
704
705	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
706
707	platform_set_drvdata(pdev, p);
708
709	return ret;
710}
711
712/*
713 * Remove serial ports registered against a platform device.
714 */
715static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
716{
717	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
718
719	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
720
721	return 0;
722}
723
724
725#ifdef CONFIG_PM
726static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
727				     pm_message_t state)
728{
729	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
730
731	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
732
733	return 0;
734}
735
736static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
737{
738	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
739
740	uart_resume_port(&lpc32xx_hs_reg, &p->port);
741
742	return 0;
743}
744#else
745#define serial_hs_lpc32xx_suspend	NULL
746#define serial_hs_lpc32xx_resume	NULL
747#endif
748
749static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
750	{ .compatible = "nxp,lpc3220-hsuart" },
751	{ /* sentinel */ }
752};
753
754MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
755
756static struct platform_driver serial_hs_lpc32xx_driver = {
757	.probe		= serial_hs_lpc32xx_probe,
758	.remove		= serial_hs_lpc32xx_remove,
759	.suspend	= serial_hs_lpc32xx_suspend,
760	.resume		= serial_hs_lpc32xx_resume,
761	.driver		= {
762		.name	= MODNAME,
763		.of_match_table	= serial_hs_lpc32xx_dt_ids,
764	},
765};
766
767static int __init lpc32xx_hsuart_init(void)
768{
769	int ret;
770
771	ret = uart_register_driver(&lpc32xx_hs_reg);
772	if (ret)
773		return ret;
774
775	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
776	if (ret)
777		uart_unregister_driver(&lpc32xx_hs_reg);
778
779	return ret;
780}
781
782static void __exit lpc32xx_hsuart_exit(void)
783{
784	platform_driver_unregister(&serial_hs_lpc32xx_driver);
785	uart_unregister_driver(&lpc32xx_hs_reg);
786}
787
788module_init(lpc32xx_hsuart_init);
789module_exit(lpc32xx_hsuart_exit);
790
791MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
792MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
793MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
794MODULE_LICENSE("GPL");