xref: /openbmc/linux/drivers/tty/serial/lpc32xx_hs.c (revision b8265621)
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 
87 struct 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"
94 static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
95 
96 #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
97 static 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 
111 static 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 
125 static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
126 {
127 	wait_for_xmit_ready(port);
128 	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
129 }
130 
131 static 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 = spin_trylock(&up->port.lock);
144 	else
145 		spin_lock(&up->port.lock);
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 		spin_unlock(&up->port.lock);
152 	local_irq_restore(flags);
153 }
154 
155 static 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 
179 static struct uart_driver lpc32xx_hsuart_reg;
180 static 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 
190 static int __init lpc32xx_hsuart_console_init(void)
191 {
192 	register_console(&lpc32xx_hsuart_console);
193 	return 0;
194 }
195 console_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 
202 static 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 };
209 static int uarts_registered;
210 
211 static 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 
242 static void __serial_uart_flush(struct uart_port *port)
243 {
244 	u32 tmp;
245 	int cnt = 0;
246 
247 	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
248 	       (cnt++ < FIFO_READ_LIMIT))
249 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
250 }
251 
252 static void __serial_lpc32xx_rx(struct uart_port *port)
253 {
254 	struct tty_port *tport = &port->state->port;
255 	unsigned int tmp, flag;
256 
257 	/* Read data from FIFO and push into terminal */
258 	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
259 	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
260 		flag = TTY_NORMAL;
261 		port->icount.rx++;
262 
263 		if (tmp & LPC32XX_HSU_ERROR_DATA) {
264 			/* Framing error */
265 			writel(LPC32XX_HSU_FE_INT,
266 			       LPC32XX_HSUART_IIR(port->membase));
267 			port->icount.frame++;
268 			flag = TTY_FRAME;
269 			tty_insert_flip_char(tport, 0, TTY_FRAME);
270 		}
271 
272 		tty_insert_flip_char(tport, (tmp & 0xFF), flag);
273 
274 		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
275 	}
276 
277 	spin_unlock(&port->lock);
278 	tty_flip_buffer_push(tport);
279 	spin_lock(&port->lock);
280 }
281 
282 static void __serial_lpc32xx_tx(struct uart_port *port)
283 {
284 	struct circ_buf *xmit = &port->state->xmit;
285 	unsigned int tmp;
286 
287 	if (port->x_char) {
288 		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
289 		port->icount.tx++;
290 		port->x_char = 0;
291 		return;
292 	}
293 
294 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
295 		goto exit_tx;
296 
297 	/* Transfer data */
298 	while (LPC32XX_HSU_TX_LEV(readl(
299 		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
300 		writel((u32) xmit->buf[xmit->tail],
301 		       LPC32XX_HSUART_FIFO(port->membase));
302 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
303 		port->icount.tx++;
304 		if (uart_circ_empty(xmit))
305 			break;
306 	}
307 
308 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
309 		uart_write_wakeup(port);
310 
311 exit_tx:
312 	if (uart_circ_empty(xmit)) {
313 		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
314 		tmp &= ~LPC32XX_HSU_TX_INT_EN;
315 		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
316 	}
317 }
318 
319 static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
320 {
321 	struct uart_port *port = dev_id;
322 	struct tty_port *tport = &port->state->port;
323 	u32 status;
324 
325 	spin_lock(&port->lock);
326 
327 	/* Read UART status and clear latched interrupts */
328 	status = readl(LPC32XX_HSUART_IIR(port->membase));
329 
330 	if (status & LPC32XX_HSU_BRK_INT) {
331 		/* Break received */
332 		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
333 		port->icount.brk++;
334 		uart_handle_break(port);
335 	}
336 
337 	/* Framing error */
338 	if (status & LPC32XX_HSU_FE_INT)
339 		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
340 
341 	if (status & LPC32XX_HSU_RX_OE_INT) {
342 		/* Receive FIFO overrun */
343 		writel(LPC32XX_HSU_RX_OE_INT,
344 		       LPC32XX_HSUART_IIR(port->membase));
345 		port->icount.overrun++;
346 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
347 		tty_schedule_flip(tport);
348 	}
349 
350 	/* Data received? */
351 	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
352 		__serial_lpc32xx_rx(port);
353 
354 	/* Transmit data request? */
355 	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
356 		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
357 		__serial_lpc32xx_tx(port);
358 	}
359 
360 	spin_unlock(&port->lock);
361 
362 	return IRQ_HANDLED;
363 }
364 
365 /* port->lock is not held.  */
366 static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
367 {
368 	unsigned int ret = 0;
369 
370 	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
371 		ret = TIOCSER_TEMT;
372 
373 	return ret;
374 }
375 
376 /* port->lock held by caller.  */
377 static void serial_lpc32xx_set_mctrl(struct uart_port *port,
378 				     unsigned int mctrl)
379 {
380 	/* No signals are supported on HS UARTs */
381 }
382 
383 /* port->lock is held by caller and interrupts are disabled.  */
384 static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
385 {
386 	/* No signals are supported on HS UARTs */
387 	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
388 }
389 
390 /* port->lock held by caller.  */
391 static void serial_lpc32xx_stop_tx(struct uart_port *port)
392 {
393 	u32 tmp;
394 
395 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
396 	tmp &= ~LPC32XX_HSU_TX_INT_EN;
397 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
398 }
399 
400 /* port->lock held by caller.  */
401 static void serial_lpc32xx_start_tx(struct uart_port *port)
402 {
403 	u32 tmp;
404 
405 	__serial_lpc32xx_tx(port);
406 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
407 	tmp |= LPC32XX_HSU_TX_INT_EN;
408 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
409 }
410 
411 /* port->lock held by caller.  */
412 static void serial_lpc32xx_stop_rx(struct uart_port *port)
413 {
414 	u32 tmp;
415 
416 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
417 	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
418 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
419 
420 	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
421 		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
422 }
423 
424 /* port->lock is not held.  */
425 static void serial_lpc32xx_break_ctl(struct uart_port *port,
426 				     int break_state)
427 {
428 	unsigned long flags;
429 	u32 tmp;
430 
431 	spin_lock_irqsave(&port->lock, flags);
432 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
433 	if (break_state != 0)
434 		tmp |= LPC32XX_HSU_BREAK;
435 	else
436 		tmp &= ~LPC32XX_HSU_BREAK;
437 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
438 	spin_unlock_irqrestore(&port->lock, flags);
439 }
440 
441 /* port->lock is not held.  */
442 static int serial_lpc32xx_startup(struct uart_port *port)
443 {
444 	int retval;
445 	unsigned long flags;
446 	u32 tmp;
447 
448 	spin_lock_irqsave(&port->lock, flags);
449 
450 	__serial_uart_flush(port);
451 
452 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
453 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
454 	       LPC32XX_HSUART_IIR(port->membase));
455 
456 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
457 
458 	/*
459 	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
460 	 * and default FIFO trigger levels
461 	 */
462 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
463 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
464 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
465 
466 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
467 
468 	spin_unlock_irqrestore(&port->lock, flags);
469 
470 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
471 			     0, MODNAME, port);
472 	if (!retval)
473 		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
474 		       LPC32XX_HSUART_CTRL(port->membase));
475 
476 	return retval;
477 }
478 
479 /* port->lock is not held.  */
480 static void serial_lpc32xx_shutdown(struct uart_port *port)
481 {
482 	u32 tmp;
483 	unsigned long flags;
484 
485 	spin_lock_irqsave(&port->lock, flags);
486 
487 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
488 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
489 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
490 
491 	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
492 
493 	spin_unlock_irqrestore(&port->lock, flags);
494 
495 	free_irq(port->irq, port);
496 }
497 
498 /* port->lock is not held.  */
499 static void serial_lpc32xx_set_termios(struct uart_port *port,
500 				       struct ktermios *termios,
501 				       struct ktermios *old)
502 {
503 	unsigned long flags;
504 	unsigned int baud, quot;
505 	u32 tmp;
506 
507 	/* Always 8-bit, no parity, 1 stop bit */
508 	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
509 	termios->c_cflag |= CS8;
510 
511 	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
512 
513 	baud = uart_get_baud_rate(port, termios, old, 0,
514 				  port->uartclk / 14);
515 
516 	quot = __serial_get_clock_div(port->uartclk, baud);
517 
518 	spin_lock_irqsave(&port->lock, flags);
519 
520 	/* Ignore characters? */
521 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
522 	if ((termios->c_cflag & CREAD) == 0)
523 		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
524 	else
525 		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
526 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
527 
528 	writel(quot, LPC32XX_HSUART_RATE(port->membase));
529 
530 	uart_update_timeout(port, termios->c_cflag, baud);
531 
532 	spin_unlock_irqrestore(&port->lock, flags);
533 
534 	/* Don't rewrite B0 */
535 	if (tty_termios_baud_rate(termios))
536 		tty_termios_encode_baud_rate(termios, baud, baud);
537 }
538 
539 static const char *serial_lpc32xx_type(struct uart_port *port)
540 {
541 	return MODNAME;
542 }
543 
544 static void serial_lpc32xx_release_port(struct uart_port *port)
545 {
546 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
547 		if (port->flags & UPF_IOREMAP) {
548 			iounmap(port->membase);
549 			port->membase = NULL;
550 		}
551 
552 		release_mem_region(port->mapbase, SZ_4K);
553 	}
554 }
555 
556 static int serial_lpc32xx_request_port(struct uart_port *port)
557 {
558 	int ret = -ENODEV;
559 
560 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
561 		ret = 0;
562 
563 		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
564 			ret = -EBUSY;
565 		else if (port->flags & UPF_IOREMAP) {
566 			port->membase = ioremap(port->mapbase, SZ_4K);
567 			if (!port->membase) {
568 				release_mem_region(port->mapbase, SZ_4K);
569 				ret = -ENOMEM;
570 			}
571 		}
572 	}
573 
574 	return ret;
575 }
576 
577 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
578 {
579 	int ret;
580 
581 	ret = serial_lpc32xx_request_port(port);
582 	if (ret < 0)
583 		return;
584 	port->type = PORT_UART00;
585 	port->fifosize = 64;
586 
587 	__serial_uart_flush(port);
588 
589 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
590 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
591 	       LPC32XX_HSUART_IIR(port->membase));
592 
593 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
594 
595 	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
596 	   and default FIFO trigger levels */
597 	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
598 	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
599 	       LPC32XX_HSUART_CTRL(port->membase));
600 }
601 
602 static int serial_lpc32xx_verify_port(struct uart_port *port,
603 				      struct serial_struct *ser)
604 {
605 	int ret = 0;
606 
607 	if (ser->type != PORT_UART00)
608 		ret = -EINVAL;
609 
610 	return ret;
611 }
612 
613 static const struct uart_ops serial_lpc32xx_pops = {
614 	.tx_empty	= serial_lpc32xx_tx_empty,
615 	.set_mctrl	= serial_lpc32xx_set_mctrl,
616 	.get_mctrl	= serial_lpc32xx_get_mctrl,
617 	.stop_tx	= serial_lpc32xx_stop_tx,
618 	.start_tx	= serial_lpc32xx_start_tx,
619 	.stop_rx	= serial_lpc32xx_stop_rx,
620 	.break_ctl	= serial_lpc32xx_break_ctl,
621 	.startup	= serial_lpc32xx_startup,
622 	.shutdown	= serial_lpc32xx_shutdown,
623 	.set_termios	= serial_lpc32xx_set_termios,
624 	.type		= serial_lpc32xx_type,
625 	.release_port	= serial_lpc32xx_release_port,
626 	.request_port	= serial_lpc32xx_request_port,
627 	.config_port	= serial_lpc32xx_config_port,
628 	.verify_port	= serial_lpc32xx_verify_port,
629 };
630 
631 /*
632  * Register a set of serial devices attached to a platform device
633  */
634 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
635 {
636 	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
637 	int ret = 0;
638 	struct resource *res;
639 
640 	if (uarts_registered >= MAX_PORTS) {
641 		dev_err(&pdev->dev,
642 			"Error: Number of possible ports exceeded (%d)!\n",
643 			uarts_registered + 1);
644 		return -ENXIO;
645 	}
646 
647 	memset(p, 0, sizeof(*p));
648 
649 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
650 	if (!res) {
651 		dev_err(&pdev->dev,
652 			"Error getting mem resource for HS UART port %d\n",
653 			uarts_registered);
654 		return -ENXIO;
655 	}
656 	p->port.mapbase = res->start;
657 	p->port.membase = NULL;
658 
659 	ret = platform_get_irq(pdev, 0);
660 	if (ret < 0)
661 		return ret;
662 	p->port.irq = ret;
663 
664 	p->port.iotype = UPIO_MEM32;
665 	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
666 	p->port.regshift = 2;
667 	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
668 	p->port.dev = &pdev->dev;
669 	p->port.ops = &serial_lpc32xx_pops;
670 	p->port.line = uarts_registered++;
671 	spin_lock_init(&p->port.lock);
672 
673 	/* send port to loopback mode by default */
674 	lpc32xx_loopback_set(p->port.mapbase, 1);
675 
676 	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
677 
678 	platform_set_drvdata(pdev, p);
679 
680 	return ret;
681 }
682 
683 /*
684  * Remove serial ports registered against a platform device.
685  */
686 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
687 {
688 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
689 
690 	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
691 
692 	return 0;
693 }
694 
695 
696 #ifdef CONFIG_PM
697 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
698 				     pm_message_t state)
699 {
700 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
701 
702 	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
703 
704 	return 0;
705 }
706 
707 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
708 {
709 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
710 
711 	uart_resume_port(&lpc32xx_hs_reg, &p->port);
712 
713 	return 0;
714 }
715 #else
716 #define serial_hs_lpc32xx_suspend	NULL
717 #define serial_hs_lpc32xx_resume	NULL
718 #endif
719 
720 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
721 	{ .compatible = "nxp,lpc3220-hsuart" },
722 	{ /* sentinel */ }
723 };
724 
725 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
726 
727 static struct platform_driver serial_hs_lpc32xx_driver = {
728 	.probe		= serial_hs_lpc32xx_probe,
729 	.remove		= serial_hs_lpc32xx_remove,
730 	.suspend	= serial_hs_lpc32xx_suspend,
731 	.resume		= serial_hs_lpc32xx_resume,
732 	.driver		= {
733 		.name	= MODNAME,
734 		.of_match_table	= serial_hs_lpc32xx_dt_ids,
735 	},
736 };
737 
738 static int __init lpc32xx_hsuart_init(void)
739 {
740 	int ret;
741 
742 	ret = uart_register_driver(&lpc32xx_hs_reg);
743 	if (ret)
744 		return ret;
745 
746 	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
747 	if (ret)
748 		uart_unregister_driver(&lpc32xx_hs_reg);
749 
750 	return ret;
751 }
752 
753 static void __exit lpc32xx_hsuart_exit(void)
754 {
755 	platform_driver_unregister(&serial_hs_lpc32xx_driver);
756 	uart_unregister_driver(&lpc32xx_hs_reg);
757 }
758 
759 module_init(lpc32xx_hsuart_init);
760 module_exit(lpc32xx_hsuart_exit);
761 
762 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
763 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
764 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
765 MODULE_LICENSE("GPL");
766