xref: /linux/drivers/tty/serial/lpc32xx_hs.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
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 	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 
251 static 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 	spin_unlock(&port->lock);
277 	tty_flip_buffer_push(tport);
278 	spin_lock(&port->lock);
279 }
280 
281 static void __serial_lpc32xx_tx(struct uart_port *port)
282 {
283 	struct circ_buf *xmit = &port->state->xmit;
284 	unsigned int tmp;
285 
286 	if (port->x_char) {
287 		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
288 		port->icount.tx++;
289 		port->x_char = 0;
290 		return;
291 	}
292 
293 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
294 		goto exit_tx;
295 
296 	/* Transfer data */
297 	while (LPC32XX_HSU_TX_LEV(readl(
298 		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
299 		writel((u32) xmit->buf[xmit->tail],
300 		       LPC32XX_HSUART_FIFO(port->membase));
301 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
302 		port->icount.tx++;
303 		if (uart_circ_empty(xmit))
304 			break;
305 	}
306 
307 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
308 		uart_write_wakeup(port);
309 
310 exit_tx:
311 	if (uart_circ_empty(xmit)) {
312 		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
313 		tmp &= ~LPC32XX_HSU_TX_INT_EN;
314 		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
315 	}
316 }
317 
318 static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
319 {
320 	struct uart_port *port = dev_id;
321 	struct tty_port *tport = &port->state->port;
322 	u32 status;
323 
324 	spin_lock(&port->lock);
325 
326 	/* Read UART status and clear latched interrupts */
327 	status = readl(LPC32XX_HSUART_IIR(port->membase));
328 
329 	if (status & LPC32XX_HSU_BRK_INT) {
330 		/* Break received */
331 		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
332 		port->icount.brk++;
333 		uart_handle_break(port);
334 	}
335 
336 	/* Framing error */
337 	if (status & LPC32XX_HSU_FE_INT)
338 		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
339 
340 	if (status & LPC32XX_HSU_RX_OE_INT) {
341 		/* Receive FIFO overrun */
342 		writel(LPC32XX_HSU_RX_OE_INT,
343 		       LPC32XX_HSUART_IIR(port->membase));
344 		port->icount.overrun++;
345 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
346 		tty_schedule_flip(tport);
347 	}
348 
349 	/* Data received? */
350 	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
351 		__serial_lpc32xx_rx(port);
352 
353 	/* Transmit data request? */
354 	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
355 		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
356 		__serial_lpc32xx_tx(port);
357 	}
358 
359 	spin_unlock(&port->lock);
360 
361 	return IRQ_HANDLED;
362 }
363 
364 /* port->lock is not held.  */
365 static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
366 {
367 	unsigned int ret = 0;
368 
369 	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
370 		ret = TIOCSER_TEMT;
371 
372 	return ret;
373 }
374 
375 /* port->lock held by caller.  */
376 static void serial_lpc32xx_set_mctrl(struct uart_port *port,
377 				     unsigned int mctrl)
378 {
379 	/* No signals are supported on HS UARTs */
380 }
381 
382 /* port->lock is held by caller and interrupts are disabled.  */
383 static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
384 {
385 	/* No signals are supported on HS UARTs */
386 	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
387 }
388 
389 /* port->lock held by caller.  */
390 static void serial_lpc32xx_stop_tx(struct uart_port *port)
391 {
392 	u32 tmp;
393 
394 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
395 	tmp &= ~LPC32XX_HSU_TX_INT_EN;
396 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
397 }
398 
399 /* port->lock held by caller.  */
400 static void serial_lpc32xx_start_tx(struct uart_port *port)
401 {
402 	u32 tmp;
403 
404 	__serial_lpc32xx_tx(port);
405 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
406 	tmp |= LPC32XX_HSU_TX_INT_EN;
407 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
408 }
409 
410 /* port->lock held by caller.  */
411 static void serial_lpc32xx_stop_rx(struct uart_port *port)
412 {
413 	u32 tmp;
414 
415 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
416 	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
417 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
418 
419 	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
420 		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
421 }
422 
423 /* port->lock is not held.  */
424 static void serial_lpc32xx_break_ctl(struct uart_port *port,
425 				     int break_state)
426 {
427 	unsigned long flags;
428 	u32 tmp;
429 
430 	spin_lock_irqsave(&port->lock, flags);
431 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
432 	if (break_state != 0)
433 		tmp |= LPC32XX_HSU_BREAK;
434 	else
435 		tmp &= ~LPC32XX_HSU_BREAK;
436 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
437 	spin_unlock_irqrestore(&port->lock, flags);
438 }
439 
440 /* port->lock is not held.  */
441 static int serial_lpc32xx_startup(struct uart_port *port)
442 {
443 	int retval;
444 	unsigned long flags;
445 	u32 tmp;
446 
447 	spin_lock_irqsave(&port->lock, flags);
448 
449 	__serial_uart_flush(port);
450 
451 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
452 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
453 	       LPC32XX_HSUART_IIR(port->membase));
454 
455 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
456 
457 	/*
458 	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
459 	 * and default FIFO trigger levels
460 	 */
461 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
462 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
463 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
464 
465 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
466 
467 	spin_unlock_irqrestore(&port->lock, flags);
468 
469 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
470 			     0, MODNAME, port);
471 	if (!retval)
472 		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
473 		       LPC32XX_HSUART_CTRL(port->membase));
474 
475 	return retval;
476 }
477 
478 /* port->lock is not held.  */
479 static void serial_lpc32xx_shutdown(struct uart_port *port)
480 {
481 	u32 tmp;
482 	unsigned long flags;
483 
484 	spin_lock_irqsave(&port->lock, flags);
485 
486 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
487 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
488 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
489 
490 	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
491 
492 	spin_unlock_irqrestore(&port->lock, flags);
493 
494 	free_irq(port->irq, port);
495 }
496 
497 /* port->lock is not held.  */
498 static void serial_lpc32xx_set_termios(struct uart_port *port,
499 				       struct ktermios *termios,
500 				       struct ktermios *old)
501 {
502 	unsigned long flags;
503 	unsigned int baud, quot;
504 	u32 tmp;
505 
506 	/* Always 8-bit, no parity, 1 stop bit */
507 	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
508 	termios->c_cflag |= CS8;
509 
510 	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
511 
512 	baud = uart_get_baud_rate(port, termios, old, 0,
513 				  port->uartclk / 14);
514 
515 	quot = __serial_get_clock_div(port->uartclk, baud);
516 
517 	spin_lock_irqsave(&port->lock, flags);
518 
519 	/* Ignore characters? */
520 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
521 	if ((termios->c_cflag & CREAD) == 0)
522 		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
523 	else
524 		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
525 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
526 
527 	writel(quot, LPC32XX_HSUART_RATE(port->membase));
528 
529 	uart_update_timeout(port, termios->c_cflag, baud);
530 
531 	spin_unlock_irqrestore(&port->lock, flags);
532 
533 	/* Don't rewrite B0 */
534 	if (tty_termios_baud_rate(termios))
535 		tty_termios_encode_baud_rate(termios, baud, baud);
536 }
537 
538 static const char *serial_lpc32xx_type(struct uart_port *port)
539 {
540 	return MODNAME;
541 }
542 
543 static void serial_lpc32xx_release_port(struct uart_port *port)
544 {
545 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
546 		if (port->flags & UPF_IOREMAP) {
547 			iounmap(port->membase);
548 			port->membase = NULL;
549 		}
550 
551 		release_mem_region(port->mapbase, SZ_4K);
552 	}
553 }
554 
555 static int serial_lpc32xx_request_port(struct uart_port *port)
556 {
557 	int ret = -ENODEV;
558 
559 	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
560 		ret = 0;
561 
562 		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
563 			ret = -EBUSY;
564 		else if (port->flags & UPF_IOREMAP) {
565 			port->membase = ioremap(port->mapbase, SZ_4K);
566 			if (!port->membase) {
567 				release_mem_region(port->mapbase, SZ_4K);
568 				ret = -ENOMEM;
569 			}
570 		}
571 	}
572 
573 	return ret;
574 }
575 
576 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
577 {
578 	int ret;
579 
580 	ret = serial_lpc32xx_request_port(port);
581 	if (ret < 0)
582 		return;
583 	port->type = PORT_UART00;
584 	port->fifosize = 64;
585 
586 	__serial_uart_flush(port);
587 
588 	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
589 		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
590 	       LPC32XX_HSUART_IIR(port->membase));
591 
592 	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
593 
594 	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
595 	   and default FIFO trigger levels */
596 	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
597 	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
598 	       LPC32XX_HSUART_CTRL(port->membase));
599 }
600 
601 static int serial_lpc32xx_verify_port(struct uart_port *port,
602 				      struct serial_struct *ser)
603 {
604 	int ret = 0;
605 
606 	if (ser->type != PORT_UART00)
607 		ret = -EINVAL;
608 
609 	return ret;
610 }
611 
612 static const struct uart_ops serial_lpc32xx_pops = {
613 	.tx_empty	= serial_lpc32xx_tx_empty,
614 	.set_mctrl	= serial_lpc32xx_set_mctrl,
615 	.get_mctrl	= serial_lpc32xx_get_mctrl,
616 	.stop_tx	= serial_lpc32xx_stop_tx,
617 	.start_tx	= serial_lpc32xx_start_tx,
618 	.stop_rx	= serial_lpc32xx_stop_rx,
619 	.break_ctl	= serial_lpc32xx_break_ctl,
620 	.startup	= serial_lpc32xx_startup,
621 	.shutdown	= serial_lpc32xx_shutdown,
622 	.set_termios	= serial_lpc32xx_set_termios,
623 	.type		= serial_lpc32xx_type,
624 	.release_port	= serial_lpc32xx_release_port,
625 	.request_port	= serial_lpc32xx_request_port,
626 	.config_port	= serial_lpc32xx_config_port,
627 	.verify_port	= serial_lpc32xx_verify_port,
628 };
629 
630 /*
631  * Register a set of serial devices attached to a platform device
632  */
633 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
634 {
635 	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
636 	int ret = 0;
637 	struct resource *res;
638 
639 	if (uarts_registered >= MAX_PORTS) {
640 		dev_err(&pdev->dev,
641 			"Error: Number of possible ports exceeded (%d)!\n",
642 			uarts_registered + 1);
643 		return -ENXIO;
644 	}
645 
646 	memset(p, 0, sizeof(*p));
647 
648 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
649 	if (!res) {
650 		dev_err(&pdev->dev,
651 			"Error getting mem resource for HS UART port %d\n",
652 			uarts_registered);
653 		return -ENXIO;
654 	}
655 	p->port.mapbase = res->start;
656 	p->port.membase = NULL;
657 
658 	ret = platform_get_irq(pdev, 0);
659 	if (ret < 0)
660 		return ret;
661 	p->port.irq = ret;
662 
663 	p->port.iotype = UPIO_MEM32;
664 	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
665 	p->port.regshift = 2;
666 	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
667 	p->port.dev = &pdev->dev;
668 	p->port.ops = &serial_lpc32xx_pops;
669 	p->port.line = uarts_registered++;
670 	spin_lock_init(&p->port.lock);
671 
672 	/* send port to loopback mode by default */
673 	lpc32xx_loopback_set(p->port.mapbase, 1);
674 
675 	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
676 
677 	platform_set_drvdata(pdev, p);
678 
679 	return ret;
680 }
681 
682 /*
683  * Remove serial ports registered against a platform device.
684  */
685 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
686 {
687 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
688 
689 	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
690 
691 	return 0;
692 }
693 
694 
695 #ifdef CONFIG_PM
696 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
697 				     pm_message_t state)
698 {
699 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
700 
701 	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
702 
703 	return 0;
704 }
705 
706 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
707 {
708 	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
709 
710 	uart_resume_port(&lpc32xx_hs_reg, &p->port);
711 
712 	return 0;
713 }
714 #else
715 #define serial_hs_lpc32xx_suspend	NULL
716 #define serial_hs_lpc32xx_resume	NULL
717 #endif
718 
719 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
720 	{ .compatible = "nxp,lpc3220-hsuart" },
721 	{ /* sentinel */ }
722 };
723 
724 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
725 
726 static struct platform_driver serial_hs_lpc32xx_driver = {
727 	.probe		= serial_hs_lpc32xx_probe,
728 	.remove		= serial_hs_lpc32xx_remove,
729 	.suspend	= serial_hs_lpc32xx_suspend,
730 	.resume		= serial_hs_lpc32xx_resume,
731 	.driver		= {
732 		.name	= MODNAME,
733 		.of_match_table	= serial_hs_lpc32xx_dt_ids,
734 	},
735 };
736 
737 static int __init lpc32xx_hsuart_init(void)
738 {
739 	int ret;
740 
741 	ret = uart_register_driver(&lpc32xx_hs_reg);
742 	if (ret)
743 		return ret;
744 
745 	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
746 	if (ret)
747 		uart_unregister_driver(&lpc32xx_hs_reg);
748 
749 	return ret;
750 }
751 
752 static void __exit lpc32xx_hsuart_exit(void)
753 {
754 	platform_driver_unregister(&serial_hs_lpc32xx_driver);
755 	uart_unregister_driver(&lpc32xx_hs_reg);
756 }
757 
758 module_init(lpc32xx_hsuart_init);
759 module_exit(lpc32xx_hsuart_exit);
760 
761 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
762 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
763 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
764 MODULE_LICENSE("GPL");
765