xref: /openbmc/linux/drivers/tty/serial/lpc32xx_hs.c (revision adb57164)
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 <linux/sizes.h>
29 #include <linux/soc/nxp/lpc32xx-misc.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 LPC32XX_MAIN_OSC_FREQ			13000000
85 
86 #define MODNAME "lpc32xx_hsuart"
87 
88 struct lpc32xx_hsuart_port {
89 	struct uart_port port;
90 };
91 
92 #define FIFO_READ_LIMIT 128
93 #define MAX_PORTS 3
94 #define LPC32XX_TTY_NAME "ttyTX"
95 static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
96 
97 #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
98 static void wait_for_xmit_empty(struct uart_port *port)
99 {
100 	unsigned int timeout = 10000;
101 
102 	do {
103 		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
104 							port->membase))) == 0)
105 			break;
106 		if (--timeout == 0)
107 			break;
108 		udelay(1);
109 	} while (1);
110 }
111 
112 static void wait_for_xmit_ready(struct uart_port *port)
113 {
114 	unsigned int timeout = 10000;
115 
116 	while (1) {
117 		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
118 							port->membase))) < 32)
119 			break;
120 		if (--timeout == 0)
121 			break;
122 		udelay(1);
123 	}
124 }
125 
126 static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
127 {
128 	wait_for_xmit_ready(port);
129 	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
130 }
131 
132 static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
133 					 unsigned int count)
134 {
135 	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
136 	unsigned long flags;
137 	int locked = 1;
138 
139 	touch_nmi_watchdog();
140 	local_irq_save(flags);
141 	if (up->port.sysrq)
142 		locked = 0;
143 	else if (oops_in_progress)
144 		locked = spin_trylock(&up->port.lock);
145 	else
146 		spin_lock(&up->port.lock);
147 
148 	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
149 	wait_for_xmit_empty(&up->port);
150 
151 	if (locked)
152 		spin_unlock(&up->port.lock);
153 	local_irq_restore(flags);
154 }
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 /* port->lock is not held.  */
443 static int serial_lpc32xx_startup(struct uart_port *port)
444 {
445 	int retval;
446 	unsigned long flags;
447 	u32 tmp;
448 
449 	spin_lock_irqsave(&port->lock, flags);
450 
451 	__serial_uart_flush(port);
452 
453 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
454 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
455 	       LPC32XX_HSUART_IIR(port->membase));
456 
457 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
458 
459 	/*
460 	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
461 	 * and default FIFO trigger levels
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, 0); /* get out of loopback mode */
468 
469 	spin_unlock_irqrestore(&port->lock, flags);
470 
471 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
472 			     0, MODNAME, port);
473 	if (!retval)
474 		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
475 		       LPC32XX_HSUART_CTRL(port->membase));
476 
477 	return retval;
478 }
479 
480 /* port->lock is not held.  */
481 static void serial_lpc32xx_shutdown(struct uart_port *port)
482 {
483 	u32 tmp;
484 	unsigned long flags;
485 
486 	spin_lock_irqsave(&port->lock, flags);
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, 1); /* go to loopback mode */
493 
494 	spin_unlock_irqrestore(&port->lock, flags);
495 
496 	free_irq(port->irq, port);
497 }
498 
499 /* port->lock is not held.  */
500 static void serial_lpc32xx_set_termios(struct uart_port *port,
501 				       struct ktermios *termios,
502 				       struct ktermios *old)
503 {
504 	unsigned long flags;
505 	unsigned int baud, quot;
506 	u32 tmp;
507 
508 	/* Always 8-bit, no parity, 1 stop bit */
509 	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
510 	termios->c_cflag |= CS8;
511 
512 	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
513 
514 	baud = uart_get_baud_rate(port, termios, old, 0,
515 				  port->uartclk / 14);
516 
517 	quot = __serial_get_clock_div(port->uartclk, baud);
518 
519 	spin_lock_irqsave(&port->lock, flags);
520 
521 	/* Ignore characters? */
522 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
523 	if ((termios->c_cflag & CREAD) == 0)
524 		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
525 	else
526 		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
527 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
528 
529 	writel(quot, LPC32XX_HSUART_RATE(port->membase));
530 
531 	uart_update_timeout(port, termios->c_cflag, baud);
532 
533 	spin_unlock_irqrestore(&port->lock, flags);
534 
535 	/* Don't rewrite B0 */
536 	if (tty_termios_baud_rate(termios))
537 		tty_termios_encode_baud_rate(termios, baud, baud);
538 }
539 
540 static const char *serial_lpc32xx_type(struct uart_port *port)
541 {
542 	return MODNAME;
543 }
544 
545 static void serial_lpc32xx_release_port(struct uart_port *port)
546 {
547 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
548 		if (port->flags & UPF_IOREMAP) {
549 			iounmap(port->membase);
550 			port->membase = NULL;
551 		}
552 
553 		release_mem_region(port->mapbase, SZ_4K);
554 	}
555 }
556 
557 static int serial_lpc32xx_request_port(struct uart_port *port)
558 {
559 	int ret = -ENODEV;
560 
561 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
562 		ret = 0;
563 
564 		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
565 			ret = -EBUSY;
566 		else if (port->flags & UPF_IOREMAP) {
567 			port->membase = ioremap(port->mapbase, SZ_4K);
568 			if (!port->membase) {
569 				release_mem_region(port->mapbase, SZ_4K);
570 				ret = -ENOMEM;
571 			}
572 		}
573 	}
574 
575 	return ret;
576 }
577 
578 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
579 {
580 	int ret;
581 
582 	ret = serial_lpc32xx_request_port(port);
583 	if (ret < 0)
584 		return;
585 	port->type = PORT_UART00;
586 	port->fifosize = 64;
587 
588 	__serial_uart_flush(port);
589 
590 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
591 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
592 	       LPC32XX_HSUART_IIR(port->membase));
593 
594 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
595 
596 	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
597 	   and default FIFO trigger levels */
598 	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
599 	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
600 	       LPC32XX_HSUART_CTRL(port->membase));
601 }
602 
603 static int serial_lpc32xx_verify_port(struct uart_port *port,
604 				      struct serial_struct *ser)
605 {
606 	int ret = 0;
607 
608 	if (ser->type != PORT_UART00)
609 		ret = -EINVAL;
610 
611 	return ret;
612 }
613 
614 static const struct uart_ops serial_lpc32xx_pops = {
615 	.tx_empty	= serial_lpc32xx_tx_empty,
616 	.set_mctrl	= serial_lpc32xx_set_mctrl,
617 	.get_mctrl	= serial_lpc32xx_get_mctrl,
618 	.stop_tx	= serial_lpc32xx_stop_tx,
619 	.start_tx	= serial_lpc32xx_start_tx,
620 	.stop_rx	= serial_lpc32xx_stop_rx,
621 	.break_ctl	= serial_lpc32xx_break_ctl,
622 	.startup	= serial_lpc32xx_startup,
623 	.shutdown	= serial_lpc32xx_shutdown,
624 	.set_termios	= serial_lpc32xx_set_termios,
625 	.type		= serial_lpc32xx_type,
626 	.release_port	= serial_lpc32xx_release_port,
627 	.request_port	= serial_lpc32xx_request_port,
628 	.config_port	= serial_lpc32xx_config_port,
629 	.verify_port	= serial_lpc32xx_verify_port,
630 };
631 
632 /*
633  * Register a set of serial devices attached to a platform device
634  */
635 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
636 {
637 	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
638 	int ret = 0;
639 	struct resource *res;
640 
641 	if (uarts_registered >= MAX_PORTS) {
642 		dev_err(&pdev->dev,
643 			"Error: Number of possible ports exceeded (%d)!\n",
644 			uarts_registered + 1);
645 		return -ENXIO;
646 	}
647 
648 	memset(p, 0, sizeof(*p));
649 
650 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
651 	if (!res) {
652 		dev_err(&pdev->dev,
653 			"Error getting mem resource for HS UART port %d\n",
654 			uarts_registered);
655 		return -ENXIO;
656 	}
657 	p->port.mapbase = res->start;
658 	p->port.membase = NULL;
659 
660 	ret = platform_get_irq(pdev, 0);
661 	if (ret < 0)
662 		return ret;
663 	p->port.irq = ret;
664 
665 	p->port.iotype = UPIO_MEM32;
666 	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
667 	p->port.regshift = 2;
668 	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
669 	p->port.dev = &pdev->dev;
670 	p->port.ops = &serial_lpc32xx_pops;
671 	p->port.line = uarts_registered++;
672 	spin_lock_init(&p->port.lock);
673 
674 	/* send port to loopback mode by default */
675 	lpc32xx_loopback_set(p->port.mapbase, 1);
676 
677 	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
678 
679 	platform_set_drvdata(pdev, p);
680 
681 	return ret;
682 }
683 
684 /*
685  * Remove serial ports registered against a platform device.
686  */
687 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
688 {
689 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
690 
691 	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
692 
693 	return 0;
694 }
695 
696 
697 #ifdef CONFIG_PM
698 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
699 				     pm_message_t state)
700 {
701 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
702 
703 	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
704 
705 	return 0;
706 }
707 
708 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
709 {
710 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
711 
712 	uart_resume_port(&lpc32xx_hs_reg, &p->port);
713 
714 	return 0;
715 }
716 #else
717 #define serial_hs_lpc32xx_suspend	NULL
718 #define serial_hs_lpc32xx_resume	NULL
719 #endif
720 
721 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
722 	{ .compatible = "nxp,lpc3220-hsuart" },
723 	{ /* sentinel */ }
724 };
725 
726 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
727 
728 static struct platform_driver serial_hs_lpc32xx_driver = {
729 	.probe		= serial_hs_lpc32xx_probe,
730 	.remove		= serial_hs_lpc32xx_remove,
731 	.suspend	= serial_hs_lpc32xx_suspend,
732 	.resume		= serial_hs_lpc32xx_resume,
733 	.driver		= {
734 		.name	= MODNAME,
735 		.of_match_table	= serial_hs_lpc32xx_dt_ids,
736 	},
737 };
738 
739 static int __init lpc32xx_hsuart_init(void)
740 {
741 	int ret;
742 
743 	ret = uart_register_driver(&lpc32xx_hs_reg);
744 	if (ret)
745 		return ret;
746 
747 	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
748 	if (ret)
749 		uart_unregister_driver(&lpc32xx_hs_reg);
750 
751 	return ret;
752 }
753 
754 static void __exit lpc32xx_hsuart_exit(void)
755 {
756 	platform_driver_unregister(&serial_hs_lpc32xx_driver);
757 	uart_unregister_driver(&lpc32xx_hs_reg);
758 }
759 
760 module_init(lpc32xx_hsuart_init);
761 module_exit(lpc32xx_hsuart_exit);
762 
763 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
764 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
765 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
766 MODULE_LICENSE("GPL");
767