xref: /openbmc/linux/drivers/tty/serial/lpc32xx_hs.c (revision f7777dcc)
1 /*
2  * High Speed Serial Ports on NXP LPC32xx SoC
3  *
4  * Authors: Kevin Wells <kevin.wells@nxp.com>
5  *          Roland Stigge <stigge@antcom.de>
6  *
7  * Copyright (C) 2010 NXP Semiconductors
8  * Copyright (C) 2012 Roland Stigge
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  */
20 
21 #include <linux/module.h>
22 #include <linux/ioport.h>
23 #include <linux/init.h>
24 #include <linux/console.h>
25 #include <linux/sysrq.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/serial_core.h>
29 #include <linux/serial.h>
30 #include <linux/platform_device.h>
31 #include <linux/delay.h>
32 #include <linux/nmi.h>
33 #include <linux/io.h>
34 #include <linux/irq.h>
35 #include <linux/gpio.h>
36 #include <linux/of.h>
37 #include <mach/platform.h>
38 #include <mach/hardware.h>
39 
40 /*
41  * High Speed UART register offsets
42  */
43 #define LPC32XX_HSUART_FIFO(x)			((x) + 0x00)
44 #define LPC32XX_HSUART_LEVEL(x)			((x) + 0x04)
45 #define LPC32XX_HSUART_IIR(x)			((x) + 0x08)
46 #define LPC32XX_HSUART_CTRL(x)			((x) + 0x0C)
47 #define LPC32XX_HSUART_RATE(x)			((x) + 0x10)
48 
49 #define LPC32XX_HSU_BREAK_DATA			(1 << 10)
50 #define LPC32XX_HSU_ERROR_DATA			(1 << 9)
51 #define LPC32XX_HSU_RX_EMPTY			(1 << 8)
52 
53 #define LPC32XX_HSU_TX_LEV(n)			(((n) >> 8) & 0xFF)
54 #define LPC32XX_HSU_RX_LEV(n)			((n) & 0xFF)
55 
56 #define LPC32XX_HSU_TX_INT_SET			(1 << 6)
57 #define LPC32XX_HSU_RX_OE_INT			(1 << 5)
58 #define LPC32XX_HSU_BRK_INT			(1 << 4)
59 #define LPC32XX_HSU_FE_INT			(1 << 3)
60 #define LPC32XX_HSU_RX_TIMEOUT_INT		(1 << 2)
61 #define LPC32XX_HSU_RX_TRIG_INT			(1 << 1)
62 #define LPC32XX_HSU_TX_INT			(1 << 0)
63 
64 #define LPC32XX_HSU_HRTS_INV			(1 << 21)
65 #define LPC32XX_HSU_HRTS_TRIG_8B		(0x0 << 19)
66 #define LPC32XX_HSU_HRTS_TRIG_16B		(0x1 << 19)
67 #define LPC32XX_HSU_HRTS_TRIG_32B		(0x2 << 19)
68 #define LPC32XX_HSU_HRTS_TRIG_48B		(0x3 << 19)
69 #define LPC32XX_HSU_HRTS_EN			(1 << 18)
70 #define LPC32XX_HSU_TMO_DISABLED		(0x0 << 16)
71 #define LPC32XX_HSU_TMO_INACT_4B		(0x1 << 16)
72 #define LPC32XX_HSU_TMO_INACT_8B		(0x2 << 16)
73 #define LPC32XX_HSU_TMO_INACT_16B		(0x3 << 16)
74 #define LPC32XX_HSU_HCTS_INV			(1 << 15)
75 #define LPC32XX_HSU_HCTS_EN			(1 << 14)
76 #define LPC32XX_HSU_OFFSET(n)			((n) << 9)
77 #define LPC32XX_HSU_BREAK			(1 << 8)
78 #define LPC32XX_HSU_ERR_INT_EN			(1 << 7)
79 #define LPC32XX_HSU_RX_INT_EN			(1 << 6)
80 #define LPC32XX_HSU_TX_INT_EN			(1 << 5)
81 #define LPC32XX_HSU_RX_TL1B			(0x0 << 2)
82 #define LPC32XX_HSU_RX_TL4B			(0x1 << 2)
83 #define LPC32XX_HSU_RX_TL8B			(0x2 << 2)
84 #define LPC32XX_HSU_RX_TL16B			(0x3 << 2)
85 #define LPC32XX_HSU_RX_TL32B			(0x4 << 2)
86 #define LPC32XX_HSU_RX_TL48B			(0x5 << 2)
87 #define LPC32XX_HSU_TX_TLEMPTY			(0x0 << 0)
88 #define LPC32XX_HSU_TX_TL0B			(0x0 << 0)
89 #define LPC32XX_HSU_TX_TL4B			(0x1 << 0)
90 #define LPC32XX_HSU_TX_TL8B			(0x2 << 0)
91 #define LPC32XX_HSU_TX_TL16B			(0x3 << 0)
92 
93 #define MODNAME "lpc32xx_hsuart"
94 
95 struct lpc32xx_hsuart_port {
96 	struct uart_port port;
97 };
98 
99 #define FIFO_READ_LIMIT 128
100 #define MAX_PORTS 3
101 #define LPC32XX_TTY_NAME "ttyTX"
102 static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
103 
104 #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
105 static void wait_for_xmit_empty(struct uart_port *port)
106 {
107 	unsigned int timeout = 10000;
108 
109 	do {
110 		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
111 							port->membase))) == 0)
112 			break;
113 		if (--timeout == 0)
114 			break;
115 		udelay(1);
116 	} while (1);
117 }
118 
119 static void wait_for_xmit_ready(struct uart_port *port)
120 {
121 	unsigned int timeout = 10000;
122 
123 	while (1) {
124 		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
125 							port->membase))) < 32)
126 			break;
127 		if (--timeout == 0)
128 			break;
129 		udelay(1);
130 	}
131 }
132 
133 static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
134 {
135 	wait_for_xmit_ready(port);
136 	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
137 }
138 
139 static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
140 					 unsigned int count)
141 {
142 	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
143 	unsigned long flags;
144 	int locked = 1;
145 
146 	touch_nmi_watchdog();
147 	local_irq_save(flags);
148 	if (up->port.sysrq)
149 		locked = 0;
150 	else if (oops_in_progress)
151 		locked = spin_trylock(&up->port.lock);
152 	else
153 		spin_lock(&up->port.lock);
154 
155 	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
156 	wait_for_xmit_empty(&up->port);
157 
158 	if (locked)
159 		spin_unlock(&up->port.lock);
160 	local_irq_restore(flags);
161 }
162 
163 static int __init lpc32xx_hsuart_console_setup(struct console *co,
164 					       char *options)
165 {
166 	struct uart_port *port;
167 	int baud = 115200;
168 	int bits = 8;
169 	int parity = 'n';
170 	int flow = 'n';
171 
172 	if (co->index >= MAX_PORTS)
173 		co->index = 0;
174 
175 	port = &lpc32xx_hs_ports[co->index].port;
176 	if (!port->membase)
177 		return -ENODEV;
178 
179 	if (options)
180 		uart_parse_options(options, &baud, &parity, &bits, &flow);
181 
182 	return uart_set_options(port, co, baud, parity, bits, flow);
183 }
184 
185 static struct uart_driver lpc32xx_hsuart_reg;
186 static struct console lpc32xx_hsuart_console = {
187 	.name		= LPC32XX_TTY_NAME,
188 	.write		= lpc32xx_hsuart_console_write,
189 	.device		= uart_console_device,
190 	.setup		= lpc32xx_hsuart_console_setup,
191 	.flags		= CON_PRINTBUFFER,
192 	.index		= -1,
193 	.data		= &lpc32xx_hsuart_reg,
194 };
195 
196 static int __init lpc32xx_hsuart_console_init(void)
197 {
198 	register_console(&lpc32xx_hsuart_console);
199 	return 0;
200 }
201 console_initcall(lpc32xx_hsuart_console_init);
202 
203 #define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
204 #else
205 #define LPC32XX_HSUART_CONSOLE NULL
206 #endif
207 
208 static struct uart_driver lpc32xx_hs_reg = {
209 	.owner		= THIS_MODULE,
210 	.driver_name	= MODNAME,
211 	.dev_name	= LPC32XX_TTY_NAME,
212 	.nr		= MAX_PORTS,
213 	.cons		= LPC32XX_HSUART_CONSOLE,
214 };
215 static int uarts_registered;
216 
217 static unsigned int __serial_get_clock_div(unsigned long uartclk,
218 					   unsigned long rate)
219 {
220 	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
221 	u32 rate_diff;
222 
223 	/* Find the closest divider to get the desired clock rate */
224 	div = uartclk / rate;
225 	goodrate = hsu_rate = (div / 14) - 1;
226 	if (hsu_rate != 0)
227 		hsu_rate--;
228 
229 	/* Tweak divider */
230 	l_hsu_rate = hsu_rate + 3;
231 	rate_diff = 0xFFFFFFFF;
232 
233 	while (hsu_rate < l_hsu_rate) {
234 		comprate = uartclk / ((hsu_rate + 1) * 14);
235 		if (abs(comprate - rate) < rate_diff) {
236 			goodrate = hsu_rate;
237 			rate_diff = abs(comprate - rate);
238 		}
239 
240 		hsu_rate++;
241 	}
242 	if (hsu_rate > 0xFF)
243 		hsu_rate = 0xFF;
244 
245 	return goodrate;
246 }
247 
248 static void __serial_uart_flush(struct uart_port *port)
249 {
250 	u32 tmp;
251 	int cnt = 0;
252 
253 	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
254 	       (cnt++ < FIFO_READ_LIMIT))
255 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
256 }
257 
258 static void __serial_lpc32xx_rx(struct uart_port *port)
259 {
260 	struct tty_port *tport = &port->state->port;
261 	unsigned int tmp, flag;
262 
263 	/* Read data from FIFO and push into terminal */
264 	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
265 	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
266 		flag = TTY_NORMAL;
267 		port->icount.rx++;
268 
269 		if (tmp & LPC32XX_HSU_ERROR_DATA) {
270 			/* Framing error */
271 			writel(LPC32XX_HSU_FE_INT,
272 			       LPC32XX_HSUART_IIR(port->membase));
273 			port->icount.frame++;
274 			flag = TTY_FRAME;
275 			tty_insert_flip_char(tport, 0, TTY_FRAME);
276 		}
277 
278 		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
279 
280 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
281 	}
282 
283 	spin_unlock(&port->lock);
284 	tty_flip_buffer_push(tport);
285 	spin_lock(&port->lock);
286 }
287 
288 static void __serial_lpc32xx_tx(struct uart_port *port)
289 {
290 	struct circ_buf *xmit = &port->state->xmit;
291 	unsigned int tmp;
292 
293 	if (port->x_char) {
294 		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
295 		port->icount.tx++;
296 		port->x_char = 0;
297 		return;
298 	}
299 
300 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
301 		goto exit_tx;
302 
303 	/* Transfer data */
304 	while (LPC32XX_HSU_TX_LEV(readl(
305 		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
306 		writel((u32) xmit->buf[xmit->tail],
307 		       LPC32XX_HSUART_FIFO(port->membase));
308 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
309 		port->icount.tx++;
310 		if (uart_circ_empty(xmit))
311 			break;
312 	}
313 
314 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
315 		uart_write_wakeup(port);
316 
317 exit_tx:
318 	if (uart_circ_empty(xmit)) {
319 		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
320 		tmp &= ~LPC32XX_HSU_TX_INT_EN;
321 		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
322 	}
323 }
324 
325 static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
326 {
327 	struct uart_port *port = dev_id;
328 	struct tty_port *tport = &port->state->port;
329 	u32 status;
330 
331 	spin_lock(&port->lock);
332 
333 	/* Read UART status and clear latched interrupts */
334 	status = readl(LPC32XX_HSUART_IIR(port->membase));
335 
336 	if (status & LPC32XX_HSU_BRK_INT) {
337 		/* Break received */
338 		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
339 		port->icount.brk++;
340 		uart_handle_break(port);
341 	}
342 
343 	/* Framing error */
344 	if (status & LPC32XX_HSU_FE_INT)
345 		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
346 
347 	if (status & LPC32XX_HSU_RX_OE_INT) {
348 		/* Receive FIFO overrun */
349 		writel(LPC32XX_HSU_RX_OE_INT,
350 		       LPC32XX_HSUART_IIR(port->membase));
351 		port->icount.overrun++;
352 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
353 		tty_schedule_flip(tport);
354 	}
355 
356 	/* Data received? */
357 	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
358 		__serial_lpc32xx_rx(port);
359 
360 	/* Transmit data request? */
361 	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
362 		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
363 		__serial_lpc32xx_tx(port);
364 	}
365 
366 	spin_unlock(&port->lock);
367 
368 	return IRQ_HANDLED;
369 }
370 
371 /* port->lock is not held.  */
372 static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
373 {
374 	unsigned int ret = 0;
375 
376 	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
377 		ret = TIOCSER_TEMT;
378 
379 	return ret;
380 }
381 
382 /* port->lock held by caller.  */
383 static void serial_lpc32xx_set_mctrl(struct uart_port *port,
384 				     unsigned int mctrl)
385 {
386 	/* No signals are supported on HS UARTs */
387 }
388 
389 /* port->lock is held by caller and interrupts are disabled.  */
390 static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
391 {
392 	/* No signals are supported on HS UARTs */
393 	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
394 }
395 
396 /* port->lock held by caller.  */
397 static void serial_lpc32xx_stop_tx(struct uart_port *port)
398 {
399 	u32 tmp;
400 
401 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
402 	tmp &= ~LPC32XX_HSU_TX_INT_EN;
403 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
404 }
405 
406 /* port->lock held by caller.  */
407 static void serial_lpc32xx_start_tx(struct uart_port *port)
408 {
409 	u32 tmp;
410 
411 	__serial_lpc32xx_tx(port);
412 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
413 	tmp |= LPC32XX_HSU_TX_INT_EN;
414 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
415 }
416 
417 /* port->lock held by caller.  */
418 static void serial_lpc32xx_stop_rx(struct uart_port *port)
419 {
420 	u32 tmp;
421 
422 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
423 	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
424 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
425 
426 	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
427 		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
428 }
429 
430 /* port->lock held by caller.  */
431 static void serial_lpc32xx_enable_ms(struct uart_port *port)
432 {
433 	/* Modem status is not supported */
434 }
435 
436 /* port->lock is not held.  */
437 static void serial_lpc32xx_break_ctl(struct uart_port *port,
438 				     int break_state)
439 {
440 	unsigned long flags;
441 	u32 tmp;
442 
443 	spin_lock_irqsave(&port->lock, flags);
444 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
445 	if (break_state != 0)
446 		tmp |= LPC32XX_HSU_BREAK;
447 	else
448 		tmp &= ~LPC32XX_HSU_BREAK;
449 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
450 	spin_unlock_irqrestore(&port->lock, flags);
451 }
452 
453 /* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
454 static void lpc32xx_loopback_set(resource_size_t mapbase, int state)
455 {
456 	int bit;
457 	u32 tmp;
458 
459 	switch (mapbase) {
460 	case LPC32XX_HS_UART1_BASE:
461 		bit = 0;
462 		break;
463 	case LPC32XX_HS_UART2_BASE:
464 		bit = 1;
465 		break;
466 	case LPC32XX_HS_UART7_BASE:
467 		bit = 6;
468 		break;
469 	default:
470 		WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
471 		return;
472 	}
473 
474 	tmp = readl(LPC32XX_UARTCTL_CLOOP);
475 	if (state)
476 		tmp |= (1 << bit);
477 	else
478 		tmp &= ~(1 << bit);
479 	writel(tmp, LPC32XX_UARTCTL_CLOOP);
480 }
481 
482 /* port->lock is not held.  */
483 static int serial_lpc32xx_startup(struct uart_port *port)
484 {
485 	int retval;
486 	unsigned long flags;
487 	u32 tmp;
488 
489 	spin_lock_irqsave(&port->lock, flags);
490 
491 	__serial_uart_flush(port);
492 
493 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
494 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
495 	       LPC32XX_HSUART_IIR(port->membase));
496 
497 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
498 
499 	/*
500 	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
501 	 * and default FIFO trigger levels
502 	 */
503 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
504 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
505 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
506 
507 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
508 
509 	spin_unlock_irqrestore(&port->lock, flags);
510 
511 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
512 			     0, MODNAME, port);
513 	if (!retval)
514 		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
515 		       LPC32XX_HSUART_CTRL(port->membase));
516 
517 	return retval;
518 }
519 
520 /* port->lock is not held.  */
521 static void serial_lpc32xx_shutdown(struct uart_port *port)
522 {
523 	u32 tmp;
524 	unsigned long flags;
525 
526 	spin_lock_irqsave(&port->lock, flags);
527 
528 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
529 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
530 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
531 
532 	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
533 
534 	spin_unlock_irqrestore(&port->lock, flags);
535 
536 	free_irq(port->irq, port);
537 }
538 
539 /* port->lock is not held.  */
540 static void serial_lpc32xx_set_termios(struct uart_port *port,
541 				       struct ktermios *termios,
542 				       struct ktermios *old)
543 {
544 	unsigned long flags;
545 	unsigned int baud, quot;
546 	u32 tmp;
547 
548 	/* Always 8-bit, no parity, 1 stop bit */
549 	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
550 	termios->c_cflag |= CS8;
551 
552 	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
553 
554 	baud = uart_get_baud_rate(port, termios, old, 0,
555 				  port->uartclk / 14);
556 
557 	quot = __serial_get_clock_div(port->uartclk, baud);
558 
559 	spin_lock_irqsave(&port->lock, flags);
560 
561 	/* Ignore characters? */
562 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
563 	if ((termios->c_cflag & CREAD) == 0)
564 		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
565 	else
566 		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
567 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
568 
569 	writel(quot, LPC32XX_HSUART_RATE(port->membase));
570 
571 	uart_update_timeout(port, termios->c_cflag, baud);
572 
573 	spin_unlock_irqrestore(&port->lock, flags);
574 
575 	/* Don't rewrite B0 */
576 	if (tty_termios_baud_rate(termios))
577 		tty_termios_encode_baud_rate(termios, baud, baud);
578 }
579 
580 static const char *serial_lpc32xx_type(struct uart_port *port)
581 {
582 	return MODNAME;
583 }
584 
585 static void serial_lpc32xx_release_port(struct uart_port *port)
586 {
587 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
588 		if (port->flags & UPF_IOREMAP) {
589 			iounmap(port->membase);
590 			port->membase = NULL;
591 		}
592 
593 		release_mem_region(port->mapbase, SZ_4K);
594 	}
595 }
596 
597 static int serial_lpc32xx_request_port(struct uart_port *port)
598 {
599 	int ret = -ENODEV;
600 
601 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
602 		ret = 0;
603 
604 		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
605 			ret = -EBUSY;
606 		else if (port->flags & UPF_IOREMAP) {
607 			port->membase = ioremap(port->mapbase, SZ_4K);
608 			if (!port->membase) {
609 				release_mem_region(port->mapbase, SZ_4K);
610 				ret = -ENOMEM;
611 			}
612 		}
613 	}
614 
615 	return ret;
616 }
617 
618 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
619 {
620 	int ret;
621 
622 	ret = serial_lpc32xx_request_port(port);
623 	if (ret < 0)
624 		return;
625 	port->type = PORT_UART00;
626 	port->fifosize = 64;
627 
628 	__serial_uart_flush(port);
629 
630 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
631 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
632 	       LPC32XX_HSUART_IIR(port->membase));
633 
634 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
635 
636 	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
637 	   and default FIFO trigger levels */
638 	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
639 	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
640 	       LPC32XX_HSUART_CTRL(port->membase));
641 }
642 
643 static int serial_lpc32xx_verify_port(struct uart_port *port,
644 				      struct serial_struct *ser)
645 {
646 	int ret = 0;
647 
648 	if (ser->type != PORT_UART00)
649 		ret = -EINVAL;
650 
651 	return ret;
652 }
653 
654 static struct uart_ops serial_lpc32xx_pops = {
655 	.tx_empty	= serial_lpc32xx_tx_empty,
656 	.set_mctrl	= serial_lpc32xx_set_mctrl,
657 	.get_mctrl	= serial_lpc32xx_get_mctrl,
658 	.stop_tx	= serial_lpc32xx_stop_tx,
659 	.start_tx	= serial_lpc32xx_start_tx,
660 	.stop_rx	= serial_lpc32xx_stop_rx,
661 	.enable_ms	= serial_lpc32xx_enable_ms,
662 	.break_ctl	= serial_lpc32xx_break_ctl,
663 	.startup	= serial_lpc32xx_startup,
664 	.shutdown	= serial_lpc32xx_shutdown,
665 	.set_termios	= serial_lpc32xx_set_termios,
666 	.type		= serial_lpc32xx_type,
667 	.release_port	= serial_lpc32xx_release_port,
668 	.request_port	= serial_lpc32xx_request_port,
669 	.config_port	= serial_lpc32xx_config_port,
670 	.verify_port	= serial_lpc32xx_verify_port,
671 };
672 
673 /*
674  * Register a set of serial devices attached to a platform device
675  */
676 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
677 {
678 	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
679 	int ret = 0;
680 	struct resource *res;
681 
682 	if (uarts_registered >= MAX_PORTS) {
683 		dev_err(&pdev->dev,
684 			"Error: Number of possible ports exceeded (%d)!\n",
685 			uarts_registered + 1);
686 		return -ENXIO;
687 	}
688 
689 	memset(p, 0, sizeof(*p));
690 
691 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
692 	if (!res) {
693 		dev_err(&pdev->dev,
694 			"Error getting mem resource for HS UART port %d\n",
695 			uarts_registered);
696 		return -ENXIO;
697 	}
698 	p->port.mapbase = res->start;
699 	p->port.membase = NULL;
700 
701 	p->port.irq = platform_get_irq(pdev, 0);
702 	if (p->port.irq < 0) {
703 		dev_err(&pdev->dev, "Error getting irq for HS UART port %d\n",
704 			uarts_registered);
705 		return p->port.irq;
706 	}
707 
708 	p->port.iotype = UPIO_MEM32;
709 	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
710 	p->port.regshift = 2;
711 	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
712 	p->port.dev = &pdev->dev;
713 	p->port.ops = &serial_lpc32xx_pops;
714 	p->port.line = uarts_registered++;
715 	spin_lock_init(&p->port.lock);
716 
717 	/* send port to loopback mode by default */
718 	lpc32xx_loopback_set(p->port.mapbase, 1);
719 
720 	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
721 
722 	platform_set_drvdata(pdev, p);
723 
724 	return ret;
725 }
726 
727 /*
728  * Remove serial ports registered against a platform device.
729  */
730 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
731 {
732 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
733 
734 	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
735 
736 	return 0;
737 }
738 
739 
740 #ifdef CONFIG_PM
741 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
742 				     pm_message_t state)
743 {
744 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
745 
746 	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
747 
748 	return 0;
749 }
750 
751 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
752 {
753 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
754 
755 	uart_resume_port(&lpc32xx_hs_reg, &p->port);
756 
757 	return 0;
758 }
759 #else
760 #define serial_hs_lpc32xx_suspend	NULL
761 #define serial_hs_lpc32xx_resume	NULL
762 #endif
763 
764 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
765 	{ .compatible = "nxp,lpc3220-hsuart" },
766 	{ /* sentinel */ }
767 };
768 
769 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
770 
771 static struct platform_driver serial_hs_lpc32xx_driver = {
772 	.probe		= serial_hs_lpc32xx_probe,
773 	.remove		= serial_hs_lpc32xx_remove,
774 	.suspend	= serial_hs_lpc32xx_suspend,
775 	.resume		= serial_hs_lpc32xx_resume,
776 	.driver		= {
777 		.name	= MODNAME,
778 		.owner	= THIS_MODULE,
779 		.of_match_table	= serial_hs_lpc32xx_dt_ids,
780 	},
781 };
782 
783 static int __init lpc32xx_hsuart_init(void)
784 {
785 	int ret;
786 
787 	ret = uart_register_driver(&lpc32xx_hs_reg);
788 	if (ret)
789 		return ret;
790 
791 	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
792 	if (ret)
793 		uart_unregister_driver(&lpc32xx_hs_reg);
794 
795 	return ret;
796 }
797 
798 static void __exit lpc32xx_hsuart_exit(void)
799 {
800 	platform_driver_unregister(&serial_hs_lpc32xx_driver);
801 	uart_unregister_driver(&lpc32xx_hs_reg);
802 }
803 
804 module_init(lpc32xx_hsuart_init);
805 module_exit(lpc32xx_hsuart_exit);
806 
807 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
808 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
809 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
810 MODULE_LICENSE("GPL");
811