1 // SPDX-License-Identifier: GPL-2.0+
3 * High Speed Serial Ports on NXP LPC32xx SoC
8 * Copyright (C) 2010 NXP Semiconductors
9 * Copyright (C) 2012 Roland Stigge
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>
25 #include <linux/irq.h>
27 #include <linux/sizes.h>
28 #include <linux/soc/nxp/lpc32xx-misc.h>
31 * High Speed UART register offsets
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)
39 #define LPC32XX_HSU_BREAK_DATA (1 << 10)
40 #define LPC32XX_HSU_ERROR_DATA (1 << 9)
41 #define LPC32XX_HSU_RX_EMPTY (1 << 8)
43 #define LPC32XX_HSU_TX_LEV(n) (((n) >> 8) & 0xFF)
44 #define LPC32XX_HSU_RX_LEV(n) ((n) & 0xFF)
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)
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)
83 #define LPC32XX_MAIN_OSC_FREQ 13000000
85 #define MODNAME "lpc32xx_hsuart"
87 struct lpc32xx_hsuart_port {
88 struct uart_port port;
91 #define FIFO_READ_LIMIT 128
93 #define LPC32XX_TTY_NAME "ttyTX"
94 static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
96 #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
97 static void wait_for_xmit_empty(struct uart_port *port)
99 unsigned int timeout = 10000;
102 if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
103 port->membase))) == 0)
111 static void wait_for_xmit_ready(struct uart_port *port)
113 unsigned int timeout = 10000;
116 if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
117 port->membase))) < 32)
125 static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
127 wait_for_xmit_ready(port);
128 writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
131 static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
134 struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
138 touch_nmi_watchdog();
139 local_irq_save(flags);
142 else if (oops_in_progress)
143 locked = spin_trylock(&up->port.lock);
145 spin_lock(&up->port.lock);
147 uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
148 wait_for_xmit_empty(&up->port);
151 spin_unlock(&up->port.lock);
152 local_irq_restore(flags);
155 static int __init lpc32xx_hsuart_console_setup(struct console *co,
158 struct uart_port *port;
164 if (co->index >= MAX_PORTS)
167 port = &lpc32xx_hs_ports[co->index].port;
172 uart_parse_options(options, &baud, &parity, &bits, &flow);
174 lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
176 return uart_set_options(port, co, baud, parity, bits, flow);
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,
187 .data = &lpc32xx_hsuart_reg,
190 static int __init lpc32xx_hsuart_console_init(void)
192 register_console(&lpc32xx_hsuart_console);
195 console_initcall(lpc32xx_hsuart_console_init);
197 #define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
199 #define LPC32XX_HSUART_CONSOLE NULL
202 static struct uart_driver lpc32xx_hs_reg = {
203 .owner = THIS_MODULE,
204 .driver_name = MODNAME,
205 .dev_name = LPC32XX_TTY_NAME,
207 .cons = LPC32XX_HSUART_CONSOLE,
209 static int uarts_registered;
211 static unsigned int __serial_get_clock_div(unsigned long uartclk,
214 u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
217 /* Find the closest divider to get the desired clock rate */
218 div = uartclk / rate;
219 goodrate = hsu_rate = (div / 14) - 1;
224 l_hsu_rate = hsu_rate + 3;
225 rate_diff = 0xFFFFFFFF;
227 while (hsu_rate < l_hsu_rate) {
228 comprate = uartclk / ((hsu_rate + 1) * 14);
229 if (abs(comprate - rate) < rate_diff) {
231 rate_diff = abs(comprate - rate);
242 static void __serial_uart_flush(struct uart_port *port)
246 while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
247 (cnt++ < FIFO_READ_LIMIT))
248 readl(LPC32XX_HSUART_FIFO(port->membase));
251 static void __serial_lpc32xx_rx(struct uart_port *port)
253 struct tty_port *tport = &port->state->port;
254 unsigned int tmp, flag;
256 /* Read data from FIFO and push into terminal */
257 tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
258 while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
262 if (tmp & LPC32XX_HSU_ERROR_DATA) {
264 writel(LPC32XX_HSU_FE_INT,
265 LPC32XX_HSUART_IIR(port->membase));
266 port->icount.frame++;
268 tty_insert_flip_char(tport, 0, TTY_FRAME);
271 tty_insert_flip_char(tport, (tmp & 0xFF), flag);
273 tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
276 tty_flip_buffer_push(tport);
279 static void __serial_lpc32xx_tx(struct uart_port *port)
281 struct circ_buf *xmit = &port->state->xmit;
285 writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
291 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
295 while (LPC32XX_HSU_TX_LEV(readl(
296 LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
297 writel((u32) xmit->buf[xmit->tail],
298 LPC32XX_HSUART_FIFO(port->membase));
299 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
301 if (uart_circ_empty(xmit))
305 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
306 uart_write_wakeup(port);
309 if (uart_circ_empty(xmit)) {
310 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
311 tmp &= ~LPC32XX_HSU_TX_INT_EN;
312 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
316 static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
318 struct uart_port *port = dev_id;
319 struct tty_port *tport = &port->state->port;
322 spin_lock(&port->lock);
324 /* Read UART status and clear latched interrupts */
325 status = readl(LPC32XX_HSUART_IIR(port->membase));
327 if (status & LPC32XX_HSU_BRK_INT) {
329 writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
331 uart_handle_break(port);
335 if (status & LPC32XX_HSU_FE_INT)
336 writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
338 if (status & LPC32XX_HSU_RX_OE_INT) {
339 /* Receive FIFO overrun */
340 writel(LPC32XX_HSU_RX_OE_INT,
341 LPC32XX_HSUART_IIR(port->membase));
342 port->icount.overrun++;
343 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
344 tty_schedule_flip(tport);
348 if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
349 __serial_lpc32xx_rx(port);
351 /* Transmit data request? */
352 if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
353 writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
354 __serial_lpc32xx_tx(port);
357 spin_unlock(&port->lock);
362 /* port->lock is not held. */
363 static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
365 unsigned int ret = 0;
367 if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
373 /* port->lock held by caller. */
374 static void serial_lpc32xx_set_mctrl(struct uart_port *port,
377 /* No signals are supported on HS UARTs */
380 /* port->lock is held by caller and interrupts are disabled. */
381 static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
383 /* No signals are supported on HS UARTs */
384 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
387 /* port->lock held by caller. */
388 static void serial_lpc32xx_stop_tx(struct uart_port *port)
392 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
393 tmp &= ~LPC32XX_HSU_TX_INT_EN;
394 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
397 /* port->lock held by caller. */
398 static void serial_lpc32xx_start_tx(struct uart_port *port)
402 __serial_lpc32xx_tx(port);
403 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
404 tmp |= LPC32XX_HSU_TX_INT_EN;
405 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
408 /* port->lock held by caller. */
409 static void serial_lpc32xx_stop_rx(struct uart_port *port)
413 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
414 tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
415 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
417 writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
418 LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
421 /* port->lock is not held. */
422 static void serial_lpc32xx_break_ctl(struct uart_port *port,
428 spin_lock_irqsave(&port->lock, flags);
429 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
430 if (break_state != 0)
431 tmp |= LPC32XX_HSU_BREAK;
433 tmp &= ~LPC32XX_HSU_BREAK;
434 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
435 spin_unlock_irqrestore(&port->lock, flags);
438 /* port->lock is not held. */
439 static int serial_lpc32xx_startup(struct uart_port *port)
445 spin_lock_irqsave(&port->lock, flags);
447 __serial_uart_flush(port);
449 writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
450 LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
451 LPC32XX_HSUART_IIR(port->membase));
453 writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
456 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
457 * and default FIFO trigger levels
459 tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
460 LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
461 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
463 lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
465 spin_unlock_irqrestore(&port->lock, flags);
467 retval = request_irq(port->irq, serial_lpc32xx_interrupt,
470 writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
471 LPC32XX_HSUART_CTRL(port->membase));
476 /* port->lock is not held. */
477 static void serial_lpc32xx_shutdown(struct uart_port *port)
482 spin_lock_irqsave(&port->lock, flags);
484 tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
485 LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
486 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
488 lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
490 spin_unlock_irqrestore(&port->lock, flags);
492 free_irq(port->irq, port);
495 /* port->lock is not held. */
496 static void serial_lpc32xx_set_termios(struct uart_port *port,
497 struct ktermios *termios,
498 struct ktermios *old)
501 unsigned int baud, quot;
504 /* Always 8-bit, no parity, 1 stop bit */
505 termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
506 termios->c_cflag |= CS8;
508 termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
510 baud = uart_get_baud_rate(port, termios, old, 0,
513 quot = __serial_get_clock_div(port->uartclk, baud);
515 spin_lock_irqsave(&port->lock, flags);
517 /* Ignore characters? */
518 tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
519 if ((termios->c_cflag & CREAD) == 0)
520 tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
522 tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
523 writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
525 writel(quot, LPC32XX_HSUART_RATE(port->membase));
527 uart_update_timeout(port, termios->c_cflag, baud);
529 spin_unlock_irqrestore(&port->lock, flags);
531 /* Don't rewrite B0 */
532 if (tty_termios_baud_rate(termios))
533 tty_termios_encode_baud_rate(termios, baud, baud);
536 static const char *serial_lpc32xx_type(struct uart_port *port)
541 static void serial_lpc32xx_release_port(struct uart_port *port)
543 if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
544 if (port->flags & UPF_IOREMAP) {
545 iounmap(port->membase);
546 port->membase = NULL;
549 release_mem_region(port->mapbase, SZ_4K);
553 static int serial_lpc32xx_request_port(struct uart_port *port)
557 if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
560 if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
562 else if (port->flags & UPF_IOREMAP) {
563 port->membase = ioremap(port->mapbase, SZ_4K);
564 if (!port->membase) {
565 release_mem_region(port->mapbase, SZ_4K);
574 static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
578 ret = serial_lpc32xx_request_port(port);
581 port->type = PORT_UART00;
584 __serial_uart_flush(port);
586 writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
587 LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
588 LPC32XX_HSUART_IIR(port->membase));
590 writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
592 /* Set receiver timeout, HSU offset of 20, no break, no interrupts,
593 and default FIFO trigger levels */
594 writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
595 LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
596 LPC32XX_HSUART_CTRL(port->membase));
599 static int serial_lpc32xx_verify_port(struct uart_port *port,
600 struct serial_struct *ser)
604 if (ser->type != PORT_UART00)
610 static const struct uart_ops serial_lpc32xx_pops = {
611 .tx_empty = serial_lpc32xx_tx_empty,
612 .set_mctrl = serial_lpc32xx_set_mctrl,
613 .get_mctrl = serial_lpc32xx_get_mctrl,
614 .stop_tx = serial_lpc32xx_stop_tx,
615 .start_tx = serial_lpc32xx_start_tx,
616 .stop_rx = serial_lpc32xx_stop_rx,
617 .break_ctl = serial_lpc32xx_break_ctl,
618 .startup = serial_lpc32xx_startup,
619 .shutdown = serial_lpc32xx_shutdown,
620 .set_termios = serial_lpc32xx_set_termios,
621 .type = serial_lpc32xx_type,
622 .release_port = serial_lpc32xx_release_port,
623 .request_port = serial_lpc32xx_request_port,
624 .config_port = serial_lpc32xx_config_port,
625 .verify_port = serial_lpc32xx_verify_port,
629 * Register a set of serial devices attached to a platform device
631 static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
633 struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
635 struct resource *res;
637 if (uarts_registered >= MAX_PORTS) {
639 "Error: Number of possible ports exceeded (%d)!\n",
640 uarts_registered + 1);
644 memset(p, 0, sizeof(*p));
646 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
649 "Error getting mem resource for HS UART port %d\n",
653 p->port.mapbase = res->start;
654 p->port.membase = NULL;
656 ret = platform_get_irq(pdev, 0);
661 p->port.iotype = UPIO_MEM32;
662 p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
663 p->port.regshift = 2;
664 p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
665 p->port.dev = &pdev->dev;
666 p->port.ops = &serial_lpc32xx_pops;
667 p->port.line = uarts_registered++;
668 spin_lock_init(&p->port.lock);
670 /* send port to loopback mode by default */
671 lpc32xx_loopback_set(p->port.mapbase, 1);
673 ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
675 platform_set_drvdata(pdev, p);
681 * Remove serial ports registered against a platform device.
683 static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
685 struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
687 uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
694 static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
697 struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
699 uart_suspend_port(&lpc32xx_hs_reg, &p->port);
704 static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
706 struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
708 uart_resume_port(&lpc32xx_hs_reg, &p->port);
713 #define serial_hs_lpc32xx_suspend NULL
714 #define serial_hs_lpc32xx_resume NULL
717 static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
718 { .compatible = "nxp,lpc3220-hsuart" },
722 MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
724 static struct platform_driver serial_hs_lpc32xx_driver = {
725 .probe = serial_hs_lpc32xx_probe,
726 .remove = serial_hs_lpc32xx_remove,
727 .suspend = serial_hs_lpc32xx_suspend,
728 .resume = serial_hs_lpc32xx_resume,
731 .of_match_table = serial_hs_lpc32xx_dt_ids,
735 static int __init lpc32xx_hsuart_init(void)
739 ret = uart_register_driver(&lpc32xx_hs_reg);
743 ret = platform_driver_register(&serial_hs_lpc32xx_driver);
745 uart_unregister_driver(&lpc32xx_hs_reg);
750 static void __exit lpc32xx_hsuart_exit(void)
752 platform_driver_unregister(&serial_hs_lpc32xx_driver);
753 uart_unregister_driver(&lpc32xx_hs_reg);
756 module_init(lpc32xx_hsuart_init);
757 module_exit(lpc32xx_hsuart_exit);
761 MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
762 MODULE_LICENSE("GPL");