xref: /linux/drivers/tty/serial/lpc32xx_hs.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
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 
86 struct 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"
93 static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
94 
95 #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
96 static 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 
110 static 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 
124 static 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 
130 static 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 
154 static void lpc32xx_loopback_set(resource_size_t mapbase, int state);
155 
156 static int __init lpc32xx_hsuart_console_setup(struct console *co,
157 					       char *options)
158 {
159 	struct uart_port *port;
160 	int baud = 115200;
161 	int bits = 8;
162 	int parity = 'n';
163 	int flow = 'n';
164 
165 	if (co->index >= MAX_PORTS)
166 		co->index = 0;
167 
168 	port = &lpc32xx_hs_ports[co->index].port;
169 	if (!port->membase)
170 		return -ENODEV;
171 
172 	if (options)
173 		uart_parse_options(options, &baud, &parity, &bits, &flow);
174 
175 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
176 
177 	return uart_set_options(port, co, baud, parity, bits, flow);
178 }
179 
180 static struct uart_driver lpc32xx_hsuart_reg;
181 static struct console lpc32xx_hsuart_console = {
182 	.name		= LPC32XX_TTY_NAME,
183 	.write		= lpc32xx_hsuart_console_write,
184 	.device		= uart_console_device,
185 	.setup		= lpc32xx_hsuart_console_setup,
186 	.flags		= CON_PRINTBUFFER,
187 	.index		= -1,
188 	.data		= &lpc32xx_hsuart_reg,
189 };
190 
191 static int __init lpc32xx_hsuart_console_init(void)
192 {
193 	register_console(&lpc32xx_hsuart_console);
194 	return 0;
195 }
196 console_initcall(lpc32xx_hsuart_console_init);
197 
198 #define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
199 #else
200 #define LPC32XX_HSUART_CONSOLE NULL
201 #endif
202 
203 static struct uart_driver lpc32xx_hs_reg = {
204 	.owner		= THIS_MODULE,
205 	.driver_name	= MODNAME,
206 	.dev_name	= LPC32XX_TTY_NAME,
207 	.nr		= MAX_PORTS,
208 	.cons		= LPC32XX_HSUART_CONSOLE,
209 };
210 static int uarts_registered;
211 
212 static unsigned int __serial_get_clock_div(unsigned long uartclk,
213 					   unsigned long rate)
214 {
215 	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
216 	u32 rate_diff;
217 
218 	/* Find the closest divider to get the desired clock rate */
219 	div = uartclk / rate;
220 	goodrate = hsu_rate = (div / 14) - 1;
221 	if (hsu_rate != 0)
222 		hsu_rate--;
223 
224 	/* Tweak divider */
225 	l_hsu_rate = hsu_rate + 3;
226 	rate_diff = 0xFFFFFFFF;
227 
228 	while (hsu_rate < l_hsu_rate) {
229 		comprate = uartclk / ((hsu_rate + 1) * 14);
230 		if (abs(comprate - rate) < rate_diff) {
231 			goodrate = hsu_rate;
232 			rate_diff = abs(comprate - rate);
233 		}
234 
235 		hsu_rate++;
236 	}
237 	if (hsu_rate > 0xFF)
238 		hsu_rate = 0xFF;
239 
240 	return goodrate;
241 }
242 
243 static void __serial_uart_flush(struct uart_port *port)
244 {
245 	u32 tmp;
246 	int cnt = 0;
247 
248 	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
249 	       (cnt++ < FIFO_READ_LIMIT))
250 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
251 }
252 
253 static void __serial_lpc32xx_rx(struct uart_port *port)
254 {
255 	struct tty_port *tport = &port->state->port;
256 	unsigned int tmp, flag;
257 
258 	/* Read data from FIFO and push into terminal */
259 	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
260 	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
261 		flag = TTY_NORMAL;
262 		port->icount.rx++;
263 
264 		if (tmp & LPC32XX_HSU_ERROR_DATA) {
265 			/* Framing error */
266 			writel(LPC32XX_HSU_FE_INT,
267 			       LPC32XX_HSUART_IIR(port->membase));
268 			port->icount.frame++;
269 			flag = TTY_FRAME;
270 			tty_insert_flip_char(tport, 0, TTY_FRAME);
271 		}
272 
273 		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
274 
275 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
276 	}
277 
278 	spin_unlock(&port->lock);
279 	tty_flip_buffer_push(tport);
280 	spin_lock(&port->lock);
281 }
282 
283 static void __serial_lpc32xx_tx(struct uart_port *port)
284 {
285 	struct circ_buf *xmit = &port->state->xmit;
286 	unsigned int tmp;
287 
288 	if (port->x_char) {
289 		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
290 		port->icount.tx++;
291 		port->x_char = 0;
292 		return;
293 	}
294 
295 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
296 		goto exit_tx;
297 
298 	/* Transfer data */
299 	while (LPC32XX_HSU_TX_LEV(readl(
300 		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
301 		writel((u32) xmit->buf[xmit->tail],
302 		       LPC32XX_HSUART_FIFO(port->membase));
303 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
304 		port->icount.tx++;
305 		if (uart_circ_empty(xmit))
306 			break;
307 	}
308 
309 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
310 		uart_write_wakeup(port);
311 
312 exit_tx:
313 	if (uart_circ_empty(xmit)) {
314 		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
315 		tmp &= ~LPC32XX_HSU_TX_INT_EN;
316 		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
317 	}
318 }
319 
320 static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
321 {
322 	struct uart_port *port = dev_id;
323 	struct tty_port *tport = &port->state->port;
324 	u32 status;
325 
326 	spin_lock(&port->lock);
327 
328 	/* Read UART status and clear latched interrupts */
329 	status = readl(LPC32XX_HSUART_IIR(port->membase));
330 
331 	if (status & LPC32XX_HSU_BRK_INT) {
332 		/* Break received */
333 		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
334 		port->icount.brk++;
335 		uart_handle_break(port);
336 	}
337 
338 	/* Framing error */
339 	if (status & LPC32XX_HSU_FE_INT)
340 		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
341 
342 	if (status & LPC32XX_HSU_RX_OE_INT) {
343 		/* Receive FIFO overrun */
344 		writel(LPC32XX_HSU_RX_OE_INT,
345 		       LPC32XX_HSUART_IIR(port->membase));
346 		port->icount.overrun++;
347 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
348 		tty_schedule_flip(tport);
349 	}
350 
351 	/* Data received? */
352 	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
353 		__serial_lpc32xx_rx(port);
354 
355 	/* Transmit data request? */
356 	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
357 		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
358 		__serial_lpc32xx_tx(port);
359 	}
360 
361 	spin_unlock(&port->lock);
362 
363 	return IRQ_HANDLED;
364 }
365 
366 /* port->lock is not held.  */
367 static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
368 {
369 	unsigned int ret = 0;
370 
371 	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
372 		ret = TIOCSER_TEMT;
373 
374 	return ret;
375 }
376 
377 /* port->lock held by caller.  */
378 static void serial_lpc32xx_set_mctrl(struct uart_port *port,
379 				     unsigned int mctrl)
380 {
381 	/* No signals are supported on HS UARTs */
382 }
383 
384 /* port->lock is held by caller and interrupts are disabled.  */
385 static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
386 {
387 	/* No signals are supported on HS UARTs */
388 	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
389 }
390 
391 /* port->lock held by caller.  */
392 static void serial_lpc32xx_stop_tx(struct uart_port *port)
393 {
394 	u32 tmp;
395 
396 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
397 	tmp &= ~LPC32XX_HSU_TX_INT_EN;
398 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
399 }
400 
401 /* port->lock held by caller.  */
402 static void serial_lpc32xx_start_tx(struct uart_port *port)
403 {
404 	u32 tmp;
405 
406 	__serial_lpc32xx_tx(port);
407 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
408 	tmp |= LPC32XX_HSU_TX_INT_EN;
409 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
410 }
411 
412 /* port->lock held by caller.  */
413 static void serial_lpc32xx_stop_rx(struct uart_port *port)
414 {
415 	u32 tmp;
416 
417 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
418 	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
419 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
420 
421 	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
422 		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
423 }
424 
425 /* port->lock is not held.  */
426 static void serial_lpc32xx_break_ctl(struct uart_port *port,
427 				     int break_state)
428 {
429 	unsigned long flags;
430 	u32 tmp;
431 
432 	spin_lock_irqsave(&port->lock, flags);
433 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
434 	if (break_state != 0)
435 		tmp |= LPC32XX_HSU_BREAK;
436 	else
437 		tmp &= ~LPC32XX_HSU_BREAK;
438 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
439 	spin_unlock_irqrestore(&port->lock, flags);
440 }
441 
442 /* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
443 static void lpc32xx_loopback_set(resource_size_t mapbase, int state)
444 {
445 	int bit;
446 	u32 tmp;
447 
448 	switch (mapbase) {
449 	case LPC32XX_HS_UART1_BASE:
450 		bit = 0;
451 		break;
452 	case LPC32XX_HS_UART2_BASE:
453 		bit = 1;
454 		break;
455 	case LPC32XX_HS_UART7_BASE:
456 		bit = 6;
457 		break;
458 	default:
459 		WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
460 		return;
461 	}
462 
463 	tmp = readl(LPC32XX_UARTCTL_CLOOP);
464 	if (state)
465 		tmp |= (1 << bit);
466 	else
467 		tmp &= ~(1 << bit);
468 	writel(tmp, LPC32XX_UARTCTL_CLOOP);
469 }
470 
471 /* port->lock is not held.  */
472 static int serial_lpc32xx_startup(struct uart_port *port)
473 {
474 	int retval;
475 	unsigned long flags;
476 	u32 tmp;
477 
478 	spin_lock_irqsave(&port->lock, flags);
479 
480 	__serial_uart_flush(port);
481 
482 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
483 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
484 	       LPC32XX_HSUART_IIR(port->membase));
485 
486 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
487 
488 	/*
489 	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
490 	 * and default FIFO trigger levels
491 	 */
492 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
493 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
494 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
495 
496 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
497 
498 	spin_unlock_irqrestore(&port->lock, flags);
499 
500 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
501 			     0, MODNAME, port);
502 	if (!retval)
503 		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
504 		       LPC32XX_HSUART_CTRL(port->membase));
505 
506 	return retval;
507 }
508 
509 /* port->lock is not held.  */
510 static void serial_lpc32xx_shutdown(struct uart_port *port)
511 {
512 	u32 tmp;
513 	unsigned long flags;
514 
515 	spin_lock_irqsave(&port->lock, flags);
516 
517 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
518 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
519 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
520 
521 	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
522 
523 	spin_unlock_irqrestore(&port->lock, flags);
524 
525 	free_irq(port->irq, port);
526 }
527 
528 /* port->lock is not held.  */
529 static void serial_lpc32xx_set_termios(struct uart_port *port,
530 				       struct ktermios *termios,
531 				       struct ktermios *old)
532 {
533 	unsigned long flags;
534 	unsigned int baud, quot;
535 	u32 tmp;
536 
537 	/* Always 8-bit, no parity, 1 stop bit */
538 	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
539 	termios->c_cflag |= CS8;
540 
541 	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
542 
543 	baud = uart_get_baud_rate(port, termios, old, 0,
544 				  port->uartclk / 14);
545 
546 	quot = __serial_get_clock_div(port->uartclk, baud);
547 
548 	spin_lock_irqsave(&port->lock, flags);
549 
550 	/* Ignore characters? */
551 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
552 	if ((termios->c_cflag & CREAD) == 0)
553 		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
554 	else
555 		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
556 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
557 
558 	writel(quot, LPC32XX_HSUART_RATE(port->membase));
559 
560 	uart_update_timeout(port, termios->c_cflag, baud);
561 
562 	spin_unlock_irqrestore(&port->lock, flags);
563 
564 	/* Don't rewrite B0 */
565 	if (tty_termios_baud_rate(termios))
566 		tty_termios_encode_baud_rate(termios, baud, baud);
567 }
568 
569 static const char *serial_lpc32xx_type(struct uart_port *port)
570 {
571 	return MODNAME;
572 }
573 
574 static void serial_lpc32xx_release_port(struct uart_port *port)
575 {
576 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
577 		if (port->flags & UPF_IOREMAP) {
578 			iounmap(port->membase);
579 			port->membase = NULL;
580 		}
581 
582 		release_mem_region(port->mapbase, SZ_4K);
583 	}
584 }
585 
586 static int serial_lpc32xx_request_port(struct uart_port *port)
587 {
588 	int ret = -ENODEV;
589 
590 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
591 		ret = 0;
592 
593 		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
594 			ret = -EBUSY;
595 		else if (port->flags & UPF_IOREMAP) {
596 			port->membase = ioremap(port->mapbase, SZ_4K);
597 			if (!port->membase) {
598 				release_mem_region(port->mapbase, SZ_4K);
599 				ret = -ENOMEM;
600 			}
601 		}
602 	}
603 
604 	return ret;
605 }
606 
607 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
608 {
609 	int ret;
610 
611 	ret = serial_lpc32xx_request_port(port);
612 	if (ret < 0)
613 		return;
614 	port->type = PORT_UART00;
615 	port->fifosize = 64;
616 
617 	__serial_uart_flush(port);
618 
619 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
620 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
621 	       LPC32XX_HSUART_IIR(port->membase));
622 
623 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
624 
625 	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
626 	   and default FIFO trigger levels */
627 	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
628 	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
629 	       LPC32XX_HSUART_CTRL(port->membase));
630 }
631 
632 static int serial_lpc32xx_verify_port(struct uart_port *port,
633 				      struct serial_struct *ser)
634 {
635 	int ret = 0;
636 
637 	if (ser->type != PORT_UART00)
638 		ret = -EINVAL;
639 
640 	return ret;
641 }
642 
643 static const struct uart_ops serial_lpc32xx_pops = {
644 	.tx_empty	= serial_lpc32xx_tx_empty,
645 	.set_mctrl	= serial_lpc32xx_set_mctrl,
646 	.get_mctrl	= serial_lpc32xx_get_mctrl,
647 	.stop_tx	= serial_lpc32xx_stop_tx,
648 	.start_tx	= serial_lpc32xx_start_tx,
649 	.stop_rx	= serial_lpc32xx_stop_rx,
650 	.break_ctl	= serial_lpc32xx_break_ctl,
651 	.startup	= serial_lpc32xx_startup,
652 	.shutdown	= serial_lpc32xx_shutdown,
653 	.set_termios	= serial_lpc32xx_set_termios,
654 	.type		= serial_lpc32xx_type,
655 	.release_port	= serial_lpc32xx_release_port,
656 	.request_port	= serial_lpc32xx_request_port,
657 	.config_port	= serial_lpc32xx_config_port,
658 	.verify_port	= serial_lpc32xx_verify_port,
659 };
660 
661 /*
662  * Register a set of serial devices attached to a platform device
663  */
664 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
665 {
666 	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
667 	int ret = 0;
668 	struct resource *res;
669 
670 	if (uarts_registered >= MAX_PORTS) {
671 		dev_err(&pdev->dev,
672 			"Error: Number of possible ports exceeded (%d)!\n",
673 			uarts_registered + 1);
674 		return -ENXIO;
675 	}
676 
677 	memset(p, 0, sizeof(*p));
678 
679 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
680 	if (!res) {
681 		dev_err(&pdev->dev,
682 			"Error getting mem resource for HS UART port %d\n",
683 			uarts_registered);
684 		return -ENXIO;
685 	}
686 	p->port.mapbase = res->start;
687 	p->port.membase = NULL;
688 
689 	ret = platform_get_irq(pdev, 0);
690 	if (ret < 0) {
691 		dev_err(&pdev->dev, "Error getting irq for HS UART port %d\n",
692 			uarts_registered);
693 		return ret;
694 	}
695 	p->port.irq = ret;
696 
697 	p->port.iotype = UPIO_MEM32;
698 	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
699 	p->port.regshift = 2;
700 	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
701 	p->port.dev = &pdev->dev;
702 	p->port.ops = &serial_lpc32xx_pops;
703 	p->port.line = uarts_registered++;
704 	spin_lock_init(&p->port.lock);
705 
706 	/* send port to loopback mode by default */
707 	lpc32xx_loopback_set(p->port.mapbase, 1);
708 
709 	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
710 
711 	platform_set_drvdata(pdev, p);
712 
713 	return ret;
714 }
715 
716 /*
717  * Remove serial ports registered against a platform device.
718  */
719 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
720 {
721 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
722 
723 	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
724 
725 	return 0;
726 }
727 
728 
729 #ifdef CONFIG_PM
730 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
731 				     pm_message_t state)
732 {
733 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
734 
735 	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
736 
737 	return 0;
738 }
739 
740 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
741 {
742 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
743 
744 	uart_resume_port(&lpc32xx_hs_reg, &p->port);
745 
746 	return 0;
747 }
748 #else
749 #define serial_hs_lpc32xx_suspend	NULL
750 #define serial_hs_lpc32xx_resume	NULL
751 #endif
752 
753 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
754 	{ .compatible = "nxp,lpc3220-hsuart" },
755 	{ /* sentinel */ }
756 };
757 
758 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
759 
760 static struct platform_driver serial_hs_lpc32xx_driver = {
761 	.probe		= serial_hs_lpc32xx_probe,
762 	.remove		= serial_hs_lpc32xx_remove,
763 	.suspend	= serial_hs_lpc32xx_suspend,
764 	.resume		= serial_hs_lpc32xx_resume,
765 	.driver		= {
766 		.name	= MODNAME,
767 		.of_match_table	= serial_hs_lpc32xx_dt_ids,
768 	},
769 };
770 
771 static int __init lpc32xx_hsuart_init(void)
772 {
773 	int ret;
774 
775 	ret = uart_register_driver(&lpc32xx_hs_reg);
776 	if (ret)
777 		return ret;
778 
779 	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
780 	if (ret)
781 		uart_unregister_driver(&lpc32xx_hs_reg);
782 
783 	return ret;
784 }
785 
786 static void __exit lpc32xx_hsuart_exit(void)
787 {
788 	platform_driver_unregister(&serial_hs_lpc32xx_driver);
789 	uart_unregister_driver(&lpc32xx_hs_reg);
790 }
791 
792 module_init(lpc32xx_hsuart_init);
793 module_exit(lpc32xx_hsuart_exit);
794 
795 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
796 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
797 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
798 MODULE_LICENSE("GPL");
799