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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for AMBA serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000 Deep Blue Solutions Ltd.
9 *
10 * This is a generic driver for ARM AMBA-type serial ports. They
11 * have a lot of 16550-like features, but are not register compatible.
12 * Note that although they do have CTS, DCD and DSR inputs, they do
13 * not have an RI input, nor do they have DTR or RTS outputs. If
14 * required, these have to be supplied via some other means (eg, GPIO)
15 * and hooked into this driver.
16 */
17
18#include <linux/module.h>
19#include <linux/ioport.h>
20#include <linux/init.h>
21#include <linux/console.h>
22#include <linux/sysrq.h>
23#include <linux/device.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/serial_core.h>
27#include <linux/serial.h>
28#include <linux/amba/bus.h>
29#include <linux/amba/serial.h>
30#include <linux/clk.h>
31#include <linux/slab.h>
32#include <linux/io.h>
33
34#define UART_NR 8
35
36#define SERIAL_AMBA_MAJOR 204
37#define SERIAL_AMBA_MINOR 16
38#define SERIAL_AMBA_NR UART_NR
39
40#define AMBA_ISR_PASS_LIMIT 256
41
42#define UART_RX_DATA(s) (((s) & UART01x_FR_RXFE) == 0)
43#define UART_TX_READY(s) (((s) & UART01x_FR_TXFF) == 0)
44
45#define UART_DUMMY_RSR_RX 256
46#define UART_PORT_SIZE 64
47
48/*
49 * We wrap our port structure around the generic uart_port.
50 */
51struct uart_amba_port {
52 struct uart_port port;
53 struct clk *clk;
54 struct amba_device *dev;
55 struct amba_pl010_data *data;
56 unsigned int old_status;
57};
58
59static void pl010_stop_tx(struct uart_port *port)
60{
61 struct uart_amba_port *uap =
62 container_of(port, struct uart_amba_port, port);
63 unsigned int cr;
64
65 cr = readb(uap->port.membase + UART010_CR);
66 cr &= ~UART010_CR_TIE;
67 writel(cr, uap->port.membase + UART010_CR);
68}
69
70static void pl010_start_tx(struct uart_port *port)
71{
72 struct uart_amba_port *uap =
73 container_of(port, struct uart_amba_port, port);
74 unsigned int cr;
75
76 cr = readb(uap->port.membase + UART010_CR);
77 cr |= UART010_CR_TIE;
78 writel(cr, uap->port.membase + UART010_CR);
79}
80
81static void pl010_stop_rx(struct uart_port *port)
82{
83 struct uart_amba_port *uap =
84 container_of(port, struct uart_amba_port, port);
85 unsigned int cr;
86
87 cr = readb(uap->port.membase + UART010_CR);
88 cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
89 writel(cr, uap->port.membase + UART010_CR);
90}
91
92static void pl010_disable_ms(struct uart_port *port)
93{
94 struct uart_amba_port *uap = (struct uart_amba_port *)port;
95 unsigned int cr;
96
97 cr = readb(uap->port.membase + UART010_CR);
98 cr &= ~UART010_CR_MSIE;
99 writel(cr, uap->port.membase + UART010_CR);
100}
101
102static void pl010_enable_ms(struct uart_port *port)
103{
104 struct uart_amba_port *uap =
105 container_of(port, struct uart_amba_port, port);
106 unsigned int cr;
107
108 cr = readb(uap->port.membase + UART010_CR);
109 cr |= UART010_CR_MSIE;
110 writel(cr, uap->port.membase + UART010_CR);
111}
112
113static void pl010_rx_chars(struct uart_port *port)
114{
115 unsigned int status, rsr, max_count = 256;
116 u8 ch, flag;
117
118 status = readb(port->membase + UART01x_FR);
119 while (UART_RX_DATA(status) && max_count--) {
120 ch = readb(port->membase + UART01x_DR);
121 flag = TTY_NORMAL;
122
123 port->icount.rx++;
124
125 /*
126 * Note that the error handling code is
127 * out of the main execution path
128 */
129 rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
130 if (unlikely(rsr & UART01x_RSR_ANY)) {
131 writel(0, port->membase + UART01x_ECR);
132
133 if (rsr & UART01x_RSR_BE) {
134 rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
135 port->icount.brk++;
136 if (uart_handle_break(port))
137 goto ignore_char;
138 } else if (rsr & UART01x_RSR_PE)
139 port->icount.parity++;
140 else if (rsr & UART01x_RSR_FE)
141 port->icount.frame++;
142 if (rsr & UART01x_RSR_OE)
143 port->icount.overrun++;
144
145 rsr &= port->read_status_mask;
146
147 if (rsr & UART01x_RSR_BE)
148 flag = TTY_BREAK;
149 else if (rsr & UART01x_RSR_PE)
150 flag = TTY_PARITY;
151 else if (rsr & UART01x_RSR_FE)
152 flag = TTY_FRAME;
153 }
154
155 if (uart_handle_sysrq_char(port, ch))
156 goto ignore_char;
157
158 uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
159
160 ignore_char:
161 status = readb(port->membase + UART01x_FR);
162 }
163 tty_flip_buffer_push(&port->state->port);
164}
165
166static void pl010_tx_chars(struct uart_port *port)
167{
168 u8 ch;
169
170 uart_port_tx_limited(port, ch, port->fifosize >> 1,
171 true,
172 writel(ch, port->membase + UART01x_DR),
173 ({}));
174}
175
176static void pl010_modem_status(struct uart_amba_port *uap)
177{
178 struct uart_port *port = &uap->port;
179 unsigned int status, delta;
180
181 writel(0, port->membase + UART010_ICR);
182
183 status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
184
185 delta = status ^ uap->old_status;
186 uap->old_status = status;
187
188 if (!delta)
189 return;
190
191 if (delta & UART01x_FR_DCD)
192 uart_handle_dcd_change(port, status & UART01x_FR_DCD);
193
194 if (delta & UART01x_FR_DSR)
195 port->icount.dsr++;
196
197 if (delta & UART01x_FR_CTS)
198 uart_handle_cts_change(port, status & UART01x_FR_CTS);
199
200 wake_up_interruptible(&port->state->port.delta_msr_wait);
201}
202
203static irqreturn_t pl010_int(int irq, void *dev_id)
204{
205 struct uart_amba_port *uap = dev_id;
206 struct uart_port *port = &uap->port;
207 unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
208 int handled = 0;
209
210 uart_port_lock(port);
211
212 status = readb(port->membase + UART010_IIR);
213 if (status) {
214 do {
215 if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
216 pl010_rx_chars(port);
217 if (status & UART010_IIR_MIS)
218 pl010_modem_status(uap);
219 if (status & UART010_IIR_TIS)
220 pl010_tx_chars(port);
221
222 if (pass_counter-- == 0)
223 break;
224
225 status = readb(port->membase + UART010_IIR);
226 } while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
227 UART010_IIR_TIS));
228 handled = 1;
229 }
230
231 uart_port_unlock(port);
232
233 return IRQ_RETVAL(handled);
234}
235
236static unsigned int pl010_tx_empty(struct uart_port *port)
237{
238 unsigned int status = readb(port->membase + UART01x_FR);
239
240 return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
241}
242
243static unsigned int pl010_get_mctrl(struct uart_port *port)
244{
245 unsigned int result = 0;
246 unsigned int status;
247
248 status = readb(port->membase + UART01x_FR);
249 if (status & UART01x_FR_DCD)
250 result |= TIOCM_CAR;
251 if (status & UART01x_FR_DSR)
252 result |= TIOCM_DSR;
253 if (status & UART01x_FR_CTS)
254 result |= TIOCM_CTS;
255
256 return result;
257}
258
259static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
260{
261 struct uart_amba_port *uap =
262 container_of(port, struct uart_amba_port, port);
263
264 if (uap->data)
265 uap->data->set_mctrl(uap->dev, port->membase, mctrl);
266}
267
268static void pl010_break_ctl(struct uart_port *port, int break_state)
269{
270 unsigned long flags;
271 unsigned int lcr_h;
272
273 uart_port_lock_irqsave(port, &flags);
274 lcr_h = readb(port->membase + UART010_LCRH);
275 if (break_state == -1)
276 lcr_h |= UART01x_LCRH_BRK;
277 else
278 lcr_h &= ~UART01x_LCRH_BRK;
279 writel(lcr_h, port->membase + UART010_LCRH);
280 uart_port_unlock_irqrestore(port, flags);
281}
282
283static int pl010_startup(struct uart_port *port)
284{
285 struct uart_amba_port *uap =
286 container_of(port, struct uart_amba_port, port);
287 int retval;
288
289 /*
290 * Try to enable the clock producer.
291 */
292 retval = clk_prepare_enable(uap->clk);
293 if (retval)
294 goto out;
295
296 port->uartclk = clk_get_rate(uap->clk);
297
298 /*
299 * Allocate the IRQ
300 */
301 retval = request_irq(port->irq, pl010_int, 0, "uart-pl010", uap);
302 if (retval)
303 goto clk_dis;
304
305 /*
306 * initialise the old status of the modem signals
307 */
308 uap->old_status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
309
310 /*
311 * Finally, enable interrupts
312 */
313 writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
314 port->membase + UART010_CR);
315
316 return 0;
317
318 clk_dis:
319 clk_disable_unprepare(uap->clk);
320 out:
321 return retval;
322}
323
324static void pl010_shutdown(struct uart_port *port)
325{
326 struct uart_amba_port *uap =
327 container_of(port, struct uart_amba_port, port);
328
329 /*
330 * Free the interrupt
331 */
332 free_irq(port->irq, uap);
333
334 /*
335 * disable all interrupts, disable the port
336 */
337 writel(0, port->membase + UART010_CR);
338
339 /* disable break condition and fifos */
340 writel(readb(port->membase + UART010_LCRH) &
341 ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
342 port->membase + UART010_LCRH);
343
344 /*
345 * Shut down the clock producer
346 */
347 clk_disable_unprepare(uap->clk);
348}
349
350static void
351pl010_set_termios(struct uart_port *port, struct ktermios *termios,
352 const struct ktermios *old)
353{
354 unsigned int lcr_h, old_cr;
355 unsigned long flags;
356 unsigned int baud, quot;
357
358 /*
359 * Ask the core to calculate the divisor for us.
360 */
361 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
362 quot = uart_get_divisor(port, baud);
363
364 switch (termios->c_cflag & CSIZE) {
365 case CS5:
366 lcr_h = UART01x_LCRH_WLEN_5;
367 break;
368 case CS6:
369 lcr_h = UART01x_LCRH_WLEN_6;
370 break;
371 case CS7:
372 lcr_h = UART01x_LCRH_WLEN_7;
373 break;
374 default: // CS8
375 lcr_h = UART01x_LCRH_WLEN_8;
376 break;
377 }
378 if (termios->c_cflag & CSTOPB)
379 lcr_h |= UART01x_LCRH_STP2;
380 if (termios->c_cflag & PARENB) {
381 lcr_h |= UART01x_LCRH_PEN;
382 if (!(termios->c_cflag & PARODD))
383 lcr_h |= UART01x_LCRH_EPS;
384 }
385 if (port->fifosize > 1)
386 lcr_h |= UART01x_LCRH_FEN;
387
388 uart_port_lock_irqsave(port, &flags);
389
390 /*
391 * Update the per-port timeout.
392 */
393 uart_update_timeout(port, termios->c_cflag, baud);
394
395 port->read_status_mask = UART01x_RSR_OE;
396 if (termios->c_iflag & INPCK)
397 port->read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
398 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
399 port->read_status_mask |= UART01x_RSR_BE;
400
401 /*
402 * Characters to ignore
403 */
404 port->ignore_status_mask = 0;
405 if (termios->c_iflag & IGNPAR)
406 port->ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
407 if (termios->c_iflag & IGNBRK) {
408 port->ignore_status_mask |= UART01x_RSR_BE;
409 /*
410 * If we're ignoring parity and break indicators,
411 * ignore overruns too (for real raw support).
412 */
413 if (termios->c_iflag & IGNPAR)
414 port->ignore_status_mask |= UART01x_RSR_OE;
415 }
416
417 /*
418 * Ignore all characters if CREAD is not set.
419 */
420 if ((termios->c_cflag & CREAD) == 0)
421 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
422
423 old_cr = readb(port->membase + UART010_CR) & ~UART010_CR_MSIE;
424
425 if (UART_ENABLE_MS(port, termios->c_cflag))
426 old_cr |= UART010_CR_MSIE;
427
428 /* Set baud rate */
429 quot -= 1;
430 writel((quot & 0xf00) >> 8, port->membase + UART010_LCRM);
431 writel(quot & 0xff, port->membase + UART010_LCRL);
432
433 /*
434 * ----------v----------v----------v----------v-----
435 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
436 * ----------^----------^----------^----------^-----
437 */
438 writel(lcr_h, port->membase + UART010_LCRH);
439 writel(old_cr, port->membase + UART010_CR);
440
441 uart_port_unlock_irqrestore(port, flags);
442}
443
444static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
445{
446 if (termios->c_line == N_PPS) {
447 port->flags |= UPF_HARDPPS_CD;
448 uart_port_lock_irq(port);
449 pl010_enable_ms(port);
450 uart_port_unlock_irq(port);
451 } else {
452 port->flags &= ~UPF_HARDPPS_CD;
453 if (!UART_ENABLE_MS(port, termios->c_cflag)) {
454 uart_port_lock_irq(port);
455 pl010_disable_ms(port);
456 uart_port_unlock_irq(port);
457 }
458 }
459}
460
461static const char *pl010_type(struct uart_port *port)
462{
463 return port->type == PORT_AMBA ? "AMBA" : NULL;
464}
465
466/*
467 * Release the memory region(s) being used by 'port'
468 */
469static void pl010_release_port(struct uart_port *port)
470{
471 release_mem_region(port->mapbase, UART_PORT_SIZE);
472}
473
474/*
475 * Request the memory region(s) being used by 'port'
476 */
477static int pl010_request_port(struct uart_port *port)
478{
479 return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
480 != NULL ? 0 : -EBUSY;
481}
482
483/*
484 * Configure/autoconfigure the port.
485 */
486static void pl010_config_port(struct uart_port *port, int flags)
487{
488 if (flags & UART_CONFIG_TYPE) {
489 port->type = PORT_AMBA;
490 pl010_request_port(port);
491 }
492}
493
494/*
495 * verify the new serial_struct (for TIOCSSERIAL).
496 */
497static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
498{
499 int ret = 0;
500 if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
501 ret = -EINVAL;
502 if (ser->irq < 0 || ser->irq >= nr_irqs)
503 ret = -EINVAL;
504 if (ser->baud_base < 9600)
505 ret = -EINVAL;
506 return ret;
507}
508
509static const struct uart_ops amba_pl010_pops = {
510 .tx_empty = pl010_tx_empty,
511 .set_mctrl = pl010_set_mctrl,
512 .get_mctrl = pl010_get_mctrl,
513 .stop_tx = pl010_stop_tx,
514 .start_tx = pl010_start_tx,
515 .stop_rx = pl010_stop_rx,
516 .enable_ms = pl010_enable_ms,
517 .break_ctl = pl010_break_ctl,
518 .startup = pl010_startup,
519 .shutdown = pl010_shutdown,
520 .set_termios = pl010_set_termios,
521 .set_ldisc = pl010_set_ldisc,
522 .type = pl010_type,
523 .release_port = pl010_release_port,
524 .request_port = pl010_request_port,
525 .config_port = pl010_config_port,
526 .verify_port = pl010_verify_port,
527};
528
529static struct uart_amba_port *amba_ports[UART_NR];
530
531#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
532
533static void pl010_console_putchar(struct uart_port *port, unsigned char ch)
534{
535 unsigned int status;
536
537 do {
538 status = readb(port->membase + UART01x_FR);
539 barrier();
540 } while (!UART_TX_READY(status));
541 writel(ch, port->membase + UART01x_DR);
542}
543
544static void
545pl010_console_write(struct console *co, const char *s, unsigned int count)
546{
547 struct uart_amba_port *uap = amba_ports[co->index];
548 struct uart_port *port = &uap->port;
549 unsigned int status, old_cr;
550
551 clk_enable(uap->clk);
552
553 /*
554 * First save the CR then disable the interrupts
555 */
556 old_cr = readb(port->membase + UART010_CR);
557 writel(UART01x_CR_UARTEN, port->membase + UART010_CR);
558
559 uart_console_write(port, s, count, pl010_console_putchar);
560
561 /*
562 * Finally, wait for transmitter to become empty
563 * and restore the TCR
564 */
565 do {
566 status = readb(port->membase + UART01x_FR);
567 barrier();
568 } while (status & UART01x_FR_BUSY);
569 writel(old_cr, port->membase + UART010_CR);
570
571 clk_disable(uap->clk);
572}
573
574static void __init
575pl010_console_get_options(struct uart_amba_port *uap, int *baud,
576 int *parity, int *bits)
577{
578 if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
579 unsigned int lcr_h, quot;
580 lcr_h = readb(uap->port.membase + UART010_LCRH);
581
582 *parity = 'n';
583 if (lcr_h & UART01x_LCRH_PEN) {
584 if (lcr_h & UART01x_LCRH_EPS)
585 *parity = 'e';
586 else
587 *parity = 'o';
588 }
589
590 if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
591 *bits = 7;
592 else
593 *bits = 8;
594
595 quot = readb(uap->port.membase + UART010_LCRL) |
596 readb(uap->port.membase + UART010_LCRM) << 8;
597 *baud = uap->port.uartclk / (16 * (quot + 1));
598 }
599}
600
601static int __init pl010_console_setup(struct console *co, char *options)
602{
603 struct uart_amba_port *uap;
604 int baud = 38400;
605 int bits = 8;
606 int parity = 'n';
607 int flow = 'n';
608 int ret;
609
610 /*
611 * Check whether an invalid uart number has been specified, and
612 * if so, search for the first available port that does have
613 * console support.
614 */
615 if (co->index >= UART_NR)
616 co->index = 0;
617 uap = amba_ports[co->index];
618 if (!uap)
619 return -ENODEV;
620
621 ret = clk_prepare(uap->clk);
622 if (ret)
623 return ret;
624
625 uap->port.uartclk = clk_get_rate(uap->clk);
626
627 if (options)
628 uart_parse_options(options, &baud, &parity, &bits, &flow);
629 else
630 pl010_console_get_options(uap, &baud, &parity, &bits);
631
632 return uart_set_options(&uap->port, co, baud, parity, bits, flow);
633}
634
635static struct uart_driver amba_reg;
636static struct console amba_console = {
637 .name = "ttyAM",
638 .write = pl010_console_write,
639 .device = uart_console_device,
640 .setup = pl010_console_setup,
641 .flags = CON_PRINTBUFFER,
642 .index = -1,
643 .data = &amba_reg,
644};
645
646#define AMBA_CONSOLE &amba_console
647#else
648#define AMBA_CONSOLE NULL
649#endif
650
651static DEFINE_MUTEX(amba_reg_lock);
652static struct uart_driver amba_reg = {
653 .owner = THIS_MODULE,
654 .driver_name = "ttyAM",
655 .dev_name = "ttyAM",
656 .major = SERIAL_AMBA_MAJOR,
657 .minor = SERIAL_AMBA_MINOR,
658 .nr = UART_NR,
659 .cons = AMBA_CONSOLE,
660};
661
662static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
663{
664 struct uart_amba_port *uap;
665 void __iomem *base;
666 int i, ret;
667
668 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
669 if (amba_ports[i] == NULL)
670 break;
671
672 if (i == ARRAY_SIZE(amba_ports))
673 return -EBUSY;
674
675 uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
676 GFP_KERNEL);
677 if (!uap)
678 return -ENOMEM;
679
680 base = devm_ioremap(&dev->dev, dev->res.start,
681 resource_size(&dev->res));
682 if (!base)
683 return -ENOMEM;
684
685 uap->clk = devm_clk_get(&dev->dev, NULL);
686 if (IS_ERR(uap->clk))
687 return PTR_ERR(uap->clk);
688
689 uap->port.dev = &dev->dev;
690 uap->port.mapbase = dev->res.start;
691 uap->port.membase = base;
692 uap->port.iotype = UPIO_MEM;
693 uap->port.irq = dev->irq[0];
694 uap->port.fifosize = 16;
695 uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
696 uap->port.ops = &amba_pl010_pops;
697 uap->port.flags = UPF_BOOT_AUTOCONF;
698 uap->port.line = i;
699 uap->dev = dev;
700 uap->data = dev_get_platdata(&dev->dev);
701
702 amba_ports[i] = uap;
703
704 amba_set_drvdata(dev, uap);
705
706 mutex_lock(&amba_reg_lock);
707 if (!amba_reg.state) {
708 ret = uart_register_driver(&amba_reg);
709 if (ret < 0) {
710 mutex_unlock(&amba_reg_lock);
711 dev_err(uap->port.dev,
712 "Failed to register AMBA-PL010 driver\n");
713 return ret;
714 }
715 }
716 mutex_unlock(&amba_reg_lock);
717
718 ret = uart_add_one_port(&amba_reg, &uap->port);
719 if (ret)
720 amba_ports[i] = NULL;
721
722 return ret;
723}
724
725static void pl010_remove(struct amba_device *dev)
726{
727 struct uart_amba_port *uap = amba_get_drvdata(dev);
728 int i;
729 bool busy = false;
730
731 uart_remove_one_port(&amba_reg, &uap->port);
732
733 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
734 if (amba_ports[i] == uap)
735 amba_ports[i] = NULL;
736 else if (amba_ports[i])
737 busy = true;
738
739 if (!busy)
740 uart_unregister_driver(&amba_reg);
741}
742
743#ifdef CONFIG_PM_SLEEP
744static int pl010_suspend(struct device *dev)
745{
746 struct uart_amba_port *uap = dev_get_drvdata(dev);
747
748 if (uap)
749 uart_suspend_port(&amba_reg, &uap->port);
750
751 return 0;
752}
753
754static int pl010_resume(struct device *dev)
755{
756 struct uart_amba_port *uap = dev_get_drvdata(dev);
757
758 if (uap)
759 uart_resume_port(&amba_reg, &uap->port);
760
761 return 0;
762}
763#endif
764
765static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
766
767static const struct amba_id pl010_ids[] = {
768 {
769 .id = 0x00041010,
770 .mask = 0x000fffff,
771 },
772 { 0, 0 },
773};
774
775MODULE_DEVICE_TABLE(amba, pl010_ids);
776
777static struct amba_driver pl010_driver = {
778 .drv = {
779 .name = "uart-pl010",
780 .pm = &pl010_dev_pm_ops,
781 },
782 .id_table = pl010_ids,
783 .probe = pl010_probe,
784 .remove = pl010_remove,
785};
786
787static int __init pl010_init(void)
788{
789 printk(KERN_INFO "Serial: AMBA driver\n");
790
791 return amba_driver_register(&pl010_driver);
792}
793
794static void __exit pl010_exit(void)
795{
796 amba_driver_unregister(&pl010_driver);
797}
798
799module_init(pl010_init);
800module_exit(pl010_exit);
801
802MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
803MODULE_DESCRIPTION("ARM AMBA serial port driver");
804MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for AMBA serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000 Deep Blue Solutions Ltd.
9 *
10 * This is a generic driver for ARM AMBA-type serial ports. They
11 * have a lot of 16550-like features, but are not register compatible.
12 * Note that although they do have CTS, DCD and DSR inputs, they do
13 * not have an RI input, nor do they have DTR or RTS outputs. If
14 * required, these have to be supplied via some other means (eg, GPIO)
15 * and hooked into this driver.
16 */
17
18#include <linux/module.h>
19#include <linux/ioport.h>
20#include <linux/init.h>
21#include <linux/console.h>
22#include <linux/sysrq.h>
23#include <linux/device.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/serial_core.h>
27#include <linux/serial.h>
28#include <linux/amba/bus.h>
29#include <linux/amba/serial.h>
30#include <linux/clk.h>
31#include <linux/slab.h>
32#include <linux/io.h>
33
34#define UART_NR 8
35
36#define SERIAL_AMBA_MAJOR 204
37#define SERIAL_AMBA_MINOR 16
38#define SERIAL_AMBA_NR UART_NR
39
40#define AMBA_ISR_PASS_LIMIT 256
41
42#define UART_RX_DATA(s) (((s) & UART01x_FR_RXFE) == 0)
43#define UART_TX_READY(s) (((s) & UART01x_FR_TXFF) == 0)
44
45#define UART_DUMMY_RSR_RX 256
46#define UART_PORT_SIZE 64
47
48/*
49 * We wrap our port structure around the generic uart_port.
50 */
51struct uart_amba_port {
52 struct uart_port port;
53 struct clk *clk;
54 struct amba_device *dev;
55 struct amba_pl010_data *data;
56 unsigned int old_status;
57};
58
59static void pl010_stop_tx(struct uart_port *port)
60{
61 struct uart_amba_port *uap =
62 container_of(port, struct uart_amba_port, port);
63 unsigned int cr;
64
65 cr = readb(uap->port.membase + UART010_CR);
66 cr &= ~UART010_CR_TIE;
67 writel(cr, uap->port.membase + UART010_CR);
68}
69
70static void pl010_start_tx(struct uart_port *port)
71{
72 struct uart_amba_port *uap =
73 container_of(port, struct uart_amba_port, port);
74 unsigned int cr;
75
76 cr = readb(uap->port.membase + UART010_CR);
77 cr |= UART010_CR_TIE;
78 writel(cr, uap->port.membase + UART010_CR);
79}
80
81static void pl010_stop_rx(struct uart_port *port)
82{
83 struct uart_amba_port *uap =
84 container_of(port, struct uart_amba_port, port);
85 unsigned int cr;
86
87 cr = readb(uap->port.membase + UART010_CR);
88 cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
89 writel(cr, uap->port.membase + UART010_CR);
90}
91
92static void pl010_disable_ms(struct uart_port *port)
93{
94 struct uart_amba_port *uap = (struct uart_amba_port *)port;
95 unsigned int cr;
96
97 cr = readb(uap->port.membase + UART010_CR);
98 cr &= ~UART010_CR_MSIE;
99 writel(cr, uap->port.membase + UART010_CR);
100}
101
102static void pl010_enable_ms(struct uart_port *port)
103{
104 struct uart_amba_port *uap =
105 container_of(port, struct uart_amba_port, port);
106 unsigned int cr;
107
108 cr = readb(uap->port.membase + UART010_CR);
109 cr |= UART010_CR_MSIE;
110 writel(cr, uap->port.membase + UART010_CR);
111}
112
113static void pl010_rx_chars(struct uart_amba_port *uap)
114{
115 unsigned int status, ch, flag, rsr, max_count = 256;
116
117 status = readb(uap->port.membase + UART01x_FR);
118 while (UART_RX_DATA(status) && max_count--) {
119 ch = readb(uap->port.membase + UART01x_DR);
120 flag = TTY_NORMAL;
121
122 uap->port.icount.rx++;
123
124 /*
125 * Note that the error handling code is
126 * out of the main execution path
127 */
128 rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
129 if (unlikely(rsr & UART01x_RSR_ANY)) {
130 writel(0, uap->port.membase + UART01x_ECR);
131
132 if (rsr & UART01x_RSR_BE) {
133 rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
134 uap->port.icount.brk++;
135 if (uart_handle_break(&uap->port))
136 goto ignore_char;
137 } else if (rsr & UART01x_RSR_PE)
138 uap->port.icount.parity++;
139 else if (rsr & UART01x_RSR_FE)
140 uap->port.icount.frame++;
141 if (rsr & UART01x_RSR_OE)
142 uap->port.icount.overrun++;
143
144 rsr &= uap->port.read_status_mask;
145
146 if (rsr & UART01x_RSR_BE)
147 flag = TTY_BREAK;
148 else if (rsr & UART01x_RSR_PE)
149 flag = TTY_PARITY;
150 else if (rsr & UART01x_RSR_FE)
151 flag = TTY_FRAME;
152 }
153
154 if (uart_handle_sysrq_char(&uap->port, ch))
155 goto ignore_char;
156
157 uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
158
159 ignore_char:
160 status = readb(uap->port.membase + UART01x_FR);
161 }
162 tty_flip_buffer_push(&uap->port.state->port);
163}
164
165static void pl010_tx_chars(struct uart_amba_port *uap)
166{
167 struct circ_buf *xmit = &uap->port.state->xmit;
168 int count;
169
170 if (uap->port.x_char) {
171 writel(uap->port.x_char, uap->port.membase + UART01x_DR);
172 uap->port.icount.tx++;
173 uap->port.x_char = 0;
174 return;
175 }
176 if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
177 pl010_stop_tx(&uap->port);
178 return;
179 }
180
181 count = uap->port.fifosize >> 1;
182 do {
183 writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
184 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
185 uap->port.icount.tx++;
186 if (uart_circ_empty(xmit))
187 break;
188 } while (--count > 0);
189
190 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
191 uart_write_wakeup(&uap->port);
192
193 if (uart_circ_empty(xmit))
194 pl010_stop_tx(&uap->port);
195}
196
197static void pl010_modem_status(struct uart_amba_port *uap)
198{
199 unsigned int status, delta;
200
201 writel(0, uap->port.membase + UART010_ICR);
202
203 status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
204
205 delta = status ^ uap->old_status;
206 uap->old_status = status;
207
208 if (!delta)
209 return;
210
211 if (delta & UART01x_FR_DCD)
212 uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
213
214 if (delta & UART01x_FR_DSR)
215 uap->port.icount.dsr++;
216
217 if (delta & UART01x_FR_CTS)
218 uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
219
220 wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
221}
222
223static irqreturn_t pl010_int(int irq, void *dev_id)
224{
225 struct uart_amba_port *uap = dev_id;
226 unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
227 int handled = 0;
228
229 spin_lock(&uap->port.lock);
230
231 status = readb(uap->port.membase + UART010_IIR);
232 if (status) {
233 do {
234 if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
235 pl010_rx_chars(uap);
236 if (status & UART010_IIR_MIS)
237 pl010_modem_status(uap);
238 if (status & UART010_IIR_TIS)
239 pl010_tx_chars(uap);
240
241 if (pass_counter-- == 0)
242 break;
243
244 status = readb(uap->port.membase + UART010_IIR);
245 } while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
246 UART010_IIR_TIS));
247 handled = 1;
248 }
249
250 spin_unlock(&uap->port.lock);
251
252 return IRQ_RETVAL(handled);
253}
254
255static unsigned int pl010_tx_empty(struct uart_port *port)
256{
257 struct uart_amba_port *uap =
258 container_of(port, struct uart_amba_port, port);
259 unsigned int status = readb(uap->port.membase + UART01x_FR);
260 return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
261}
262
263static unsigned int pl010_get_mctrl(struct uart_port *port)
264{
265 struct uart_amba_port *uap =
266 container_of(port, struct uart_amba_port, port);
267 unsigned int result = 0;
268 unsigned int status;
269
270 status = readb(uap->port.membase + UART01x_FR);
271 if (status & UART01x_FR_DCD)
272 result |= TIOCM_CAR;
273 if (status & UART01x_FR_DSR)
274 result |= TIOCM_DSR;
275 if (status & UART01x_FR_CTS)
276 result |= TIOCM_CTS;
277
278 return result;
279}
280
281static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
282{
283 struct uart_amba_port *uap =
284 container_of(port, struct uart_amba_port, port);
285
286 if (uap->data)
287 uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
288}
289
290static void pl010_break_ctl(struct uart_port *port, int break_state)
291{
292 struct uart_amba_port *uap =
293 container_of(port, struct uart_amba_port, port);
294 unsigned long flags;
295 unsigned int lcr_h;
296
297 spin_lock_irqsave(&uap->port.lock, flags);
298 lcr_h = readb(uap->port.membase + UART010_LCRH);
299 if (break_state == -1)
300 lcr_h |= UART01x_LCRH_BRK;
301 else
302 lcr_h &= ~UART01x_LCRH_BRK;
303 writel(lcr_h, uap->port.membase + UART010_LCRH);
304 spin_unlock_irqrestore(&uap->port.lock, flags);
305}
306
307static int pl010_startup(struct uart_port *port)
308{
309 struct uart_amba_port *uap =
310 container_of(port, struct uart_amba_port, port);
311 int retval;
312
313 /*
314 * Try to enable the clock producer.
315 */
316 retval = clk_prepare_enable(uap->clk);
317 if (retval)
318 goto out;
319
320 uap->port.uartclk = clk_get_rate(uap->clk);
321
322 /*
323 * Allocate the IRQ
324 */
325 retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
326 if (retval)
327 goto clk_dis;
328
329 /*
330 * initialise the old status of the modem signals
331 */
332 uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
333
334 /*
335 * Finally, enable interrupts
336 */
337 writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
338 uap->port.membase + UART010_CR);
339
340 return 0;
341
342 clk_dis:
343 clk_disable_unprepare(uap->clk);
344 out:
345 return retval;
346}
347
348static void pl010_shutdown(struct uart_port *port)
349{
350 struct uart_amba_port *uap =
351 container_of(port, struct uart_amba_port, port);
352
353 /*
354 * Free the interrupt
355 */
356 free_irq(uap->port.irq, uap);
357
358 /*
359 * disable all interrupts, disable the port
360 */
361 writel(0, uap->port.membase + UART010_CR);
362
363 /* disable break condition and fifos */
364 writel(readb(uap->port.membase + UART010_LCRH) &
365 ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
366 uap->port.membase + UART010_LCRH);
367
368 /*
369 * Shut down the clock producer
370 */
371 clk_disable_unprepare(uap->clk);
372}
373
374static void
375pl010_set_termios(struct uart_port *port, struct ktermios *termios,
376 struct ktermios *old)
377{
378 struct uart_amba_port *uap =
379 container_of(port, struct uart_amba_port, port);
380 unsigned int lcr_h, old_cr;
381 unsigned long flags;
382 unsigned int baud, quot;
383
384 /*
385 * Ask the core to calculate the divisor for us.
386 */
387 baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
388 quot = uart_get_divisor(port, baud);
389
390 switch (termios->c_cflag & CSIZE) {
391 case CS5:
392 lcr_h = UART01x_LCRH_WLEN_5;
393 break;
394 case CS6:
395 lcr_h = UART01x_LCRH_WLEN_6;
396 break;
397 case CS7:
398 lcr_h = UART01x_LCRH_WLEN_7;
399 break;
400 default: // CS8
401 lcr_h = UART01x_LCRH_WLEN_8;
402 break;
403 }
404 if (termios->c_cflag & CSTOPB)
405 lcr_h |= UART01x_LCRH_STP2;
406 if (termios->c_cflag & PARENB) {
407 lcr_h |= UART01x_LCRH_PEN;
408 if (!(termios->c_cflag & PARODD))
409 lcr_h |= UART01x_LCRH_EPS;
410 }
411 if (uap->port.fifosize > 1)
412 lcr_h |= UART01x_LCRH_FEN;
413
414 spin_lock_irqsave(&uap->port.lock, flags);
415
416 /*
417 * Update the per-port timeout.
418 */
419 uart_update_timeout(port, termios->c_cflag, baud);
420
421 uap->port.read_status_mask = UART01x_RSR_OE;
422 if (termios->c_iflag & INPCK)
423 uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
424 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
425 uap->port.read_status_mask |= UART01x_RSR_BE;
426
427 /*
428 * Characters to ignore
429 */
430 uap->port.ignore_status_mask = 0;
431 if (termios->c_iflag & IGNPAR)
432 uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
433 if (termios->c_iflag & IGNBRK) {
434 uap->port.ignore_status_mask |= UART01x_RSR_BE;
435 /*
436 * If we're ignoring parity and break indicators,
437 * ignore overruns too (for real raw support).
438 */
439 if (termios->c_iflag & IGNPAR)
440 uap->port.ignore_status_mask |= UART01x_RSR_OE;
441 }
442
443 /*
444 * Ignore all characters if CREAD is not set.
445 */
446 if ((termios->c_cflag & CREAD) == 0)
447 uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
448
449 /* first, disable everything */
450 old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
451
452 if (UART_ENABLE_MS(port, termios->c_cflag))
453 old_cr |= UART010_CR_MSIE;
454
455 writel(0, uap->port.membase + UART010_CR);
456
457 /* Set baud rate */
458 quot -= 1;
459 writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
460 writel(quot & 0xff, uap->port.membase + UART010_LCRL);
461
462 /*
463 * ----------v----------v----------v----------v-----
464 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
465 * ----------^----------^----------^----------^-----
466 */
467 writel(lcr_h, uap->port.membase + UART010_LCRH);
468 writel(old_cr, uap->port.membase + UART010_CR);
469
470 spin_unlock_irqrestore(&uap->port.lock, flags);
471}
472
473static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
474{
475 if (termios->c_line == N_PPS) {
476 port->flags |= UPF_HARDPPS_CD;
477 spin_lock_irq(&port->lock);
478 pl010_enable_ms(port);
479 spin_unlock_irq(&port->lock);
480 } else {
481 port->flags &= ~UPF_HARDPPS_CD;
482 if (!UART_ENABLE_MS(port, termios->c_cflag)) {
483 spin_lock_irq(&port->lock);
484 pl010_disable_ms(port);
485 spin_unlock_irq(&port->lock);
486 }
487 }
488}
489
490static const char *pl010_type(struct uart_port *port)
491{
492 return port->type == PORT_AMBA ? "AMBA" : NULL;
493}
494
495/*
496 * Release the memory region(s) being used by 'port'
497 */
498static void pl010_release_port(struct uart_port *port)
499{
500 release_mem_region(port->mapbase, UART_PORT_SIZE);
501}
502
503/*
504 * Request the memory region(s) being used by 'port'
505 */
506static int pl010_request_port(struct uart_port *port)
507{
508 return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
509 != NULL ? 0 : -EBUSY;
510}
511
512/*
513 * Configure/autoconfigure the port.
514 */
515static void pl010_config_port(struct uart_port *port, int flags)
516{
517 if (flags & UART_CONFIG_TYPE) {
518 port->type = PORT_AMBA;
519 pl010_request_port(port);
520 }
521}
522
523/*
524 * verify the new serial_struct (for TIOCSSERIAL).
525 */
526static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
527{
528 int ret = 0;
529 if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
530 ret = -EINVAL;
531 if (ser->irq < 0 || ser->irq >= nr_irqs)
532 ret = -EINVAL;
533 if (ser->baud_base < 9600)
534 ret = -EINVAL;
535 return ret;
536}
537
538static const struct uart_ops amba_pl010_pops = {
539 .tx_empty = pl010_tx_empty,
540 .set_mctrl = pl010_set_mctrl,
541 .get_mctrl = pl010_get_mctrl,
542 .stop_tx = pl010_stop_tx,
543 .start_tx = pl010_start_tx,
544 .stop_rx = pl010_stop_rx,
545 .enable_ms = pl010_enable_ms,
546 .break_ctl = pl010_break_ctl,
547 .startup = pl010_startup,
548 .shutdown = pl010_shutdown,
549 .set_termios = pl010_set_termios,
550 .set_ldisc = pl010_set_ldisc,
551 .type = pl010_type,
552 .release_port = pl010_release_port,
553 .request_port = pl010_request_port,
554 .config_port = pl010_config_port,
555 .verify_port = pl010_verify_port,
556};
557
558static struct uart_amba_port *amba_ports[UART_NR];
559
560#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
561
562static void pl010_console_putchar(struct uart_port *port, int ch)
563{
564 struct uart_amba_port *uap =
565 container_of(port, struct uart_amba_port, port);
566 unsigned int status;
567
568 do {
569 status = readb(uap->port.membase + UART01x_FR);
570 barrier();
571 } while (!UART_TX_READY(status));
572 writel(ch, uap->port.membase + UART01x_DR);
573}
574
575static void
576pl010_console_write(struct console *co, const char *s, unsigned int count)
577{
578 struct uart_amba_port *uap = amba_ports[co->index];
579 unsigned int status, old_cr;
580
581 clk_enable(uap->clk);
582
583 /*
584 * First save the CR then disable the interrupts
585 */
586 old_cr = readb(uap->port.membase + UART010_CR);
587 writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
588
589 uart_console_write(&uap->port, s, count, pl010_console_putchar);
590
591 /*
592 * Finally, wait for transmitter to become empty
593 * and restore the TCR
594 */
595 do {
596 status = readb(uap->port.membase + UART01x_FR);
597 barrier();
598 } while (status & UART01x_FR_BUSY);
599 writel(old_cr, uap->port.membase + UART010_CR);
600
601 clk_disable(uap->clk);
602}
603
604static void __init
605pl010_console_get_options(struct uart_amba_port *uap, int *baud,
606 int *parity, int *bits)
607{
608 if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
609 unsigned int lcr_h, quot;
610 lcr_h = readb(uap->port.membase + UART010_LCRH);
611
612 *parity = 'n';
613 if (lcr_h & UART01x_LCRH_PEN) {
614 if (lcr_h & UART01x_LCRH_EPS)
615 *parity = 'e';
616 else
617 *parity = 'o';
618 }
619
620 if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
621 *bits = 7;
622 else
623 *bits = 8;
624
625 quot = readb(uap->port.membase + UART010_LCRL) |
626 readb(uap->port.membase + UART010_LCRM) << 8;
627 *baud = uap->port.uartclk / (16 * (quot + 1));
628 }
629}
630
631static int __init pl010_console_setup(struct console *co, char *options)
632{
633 struct uart_amba_port *uap;
634 int baud = 38400;
635 int bits = 8;
636 int parity = 'n';
637 int flow = 'n';
638 int ret;
639
640 /*
641 * Check whether an invalid uart number has been specified, and
642 * if so, search for the first available port that does have
643 * console support.
644 */
645 if (co->index >= UART_NR)
646 co->index = 0;
647 uap = amba_ports[co->index];
648 if (!uap)
649 return -ENODEV;
650
651 ret = clk_prepare(uap->clk);
652 if (ret)
653 return ret;
654
655 uap->port.uartclk = clk_get_rate(uap->clk);
656
657 if (options)
658 uart_parse_options(options, &baud, &parity, &bits, &flow);
659 else
660 pl010_console_get_options(uap, &baud, &parity, &bits);
661
662 return uart_set_options(&uap->port, co, baud, parity, bits, flow);
663}
664
665static struct uart_driver amba_reg;
666static struct console amba_console = {
667 .name = "ttyAM",
668 .write = pl010_console_write,
669 .device = uart_console_device,
670 .setup = pl010_console_setup,
671 .flags = CON_PRINTBUFFER,
672 .index = -1,
673 .data = &amba_reg,
674};
675
676#define AMBA_CONSOLE &amba_console
677#else
678#define AMBA_CONSOLE NULL
679#endif
680
681static DEFINE_MUTEX(amba_reg_lock);
682static struct uart_driver amba_reg = {
683 .owner = THIS_MODULE,
684 .driver_name = "ttyAM",
685 .dev_name = "ttyAM",
686 .major = SERIAL_AMBA_MAJOR,
687 .minor = SERIAL_AMBA_MINOR,
688 .nr = UART_NR,
689 .cons = AMBA_CONSOLE,
690};
691
692static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
693{
694 struct uart_amba_port *uap;
695 void __iomem *base;
696 int i, ret;
697
698 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
699 if (amba_ports[i] == NULL)
700 break;
701
702 if (i == ARRAY_SIZE(amba_ports))
703 return -EBUSY;
704
705 uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
706 GFP_KERNEL);
707 if (!uap)
708 return -ENOMEM;
709
710 base = devm_ioremap(&dev->dev, dev->res.start,
711 resource_size(&dev->res));
712 if (!base)
713 return -ENOMEM;
714
715 uap->clk = devm_clk_get(&dev->dev, NULL);
716 if (IS_ERR(uap->clk))
717 return PTR_ERR(uap->clk);
718
719 uap->port.dev = &dev->dev;
720 uap->port.mapbase = dev->res.start;
721 uap->port.membase = base;
722 uap->port.iotype = UPIO_MEM;
723 uap->port.irq = dev->irq[0];
724 uap->port.fifosize = 16;
725 uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
726 uap->port.ops = &amba_pl010_pops;
727 uap->port.flags = UPF_BOOT_AUTOCONF;
728 uap->port.line = i;
729 uap->dev = dev;
730 uap->data = dev_get_platdata(&dev->dev);
731
732 amba_ports[i] = uap;
733
734 amba_set_drvdata(dev, uap);
735
736 mutex_lock(&amba_reg_lock);
737 if (!amba_reg.state) {
738 ret = uart_register_driver(&amba_reg);
739 if (ret < 0) {
740 mutex_unlock(&amba_reg_lock);
741 dev_err(uap->port.dev,
742 "Failed to register AMBA-PL010 driver\n");
743 return ret;
744 }
745 }
746 mutex_unlock(&amba_reg_lock);
747
748 ret = uart_add_one_port(&amba_reg, &uap->port);
749 if (ret)
750 amba_ports[i] = NULL;
751
752 return ret;
753}
754
755static void pl010_remove(struct amba_device *dev)
756{
757 struct uart_amba_port *uap = amba_get_drvdata(dev);
758 int i;
759 bool busy = false;
760
761 uart_remove_one_port(&amba_reg, &uap->port);
762
763 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
764 if (amba_ports[i] == uap)
765 amba_ports[i] = NULL;
766 else if (amba_ports[i])
767 busy = true;
768
769 if (!busy)
770 uart_unregister_driver(&amba_reg);
771}
772
773#ifdef CONFIG_PM_SLEEP
774static int pl010_suspend(struct device *dev)
775{
776 struct uart_amba_port *uap = dev_get_drvdata(dev);
777
778 if (uap)
779 uart_suspend_port(&amba_reg, &uap->port);
780
781 return 0;
782}
783
784static int pl010_resume(struct device *dev)
785{
786 struct uart_amba_port *uap = dev_get_drvdata(dev);
787
788 if (uap)
789 uart_resume_port(&amba_reg, &uap->port);
790
791 return 0;
792}
793#endif
794
795static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
796
797static const struct amba_id pl010_ids[] = {
798 {
799 .id = 0x00041010,
800 .mask = 0x000fffff,
801 },
802 { 0, 0 },
803};
804
805MODULE_DEVICE_TABLE(amba, pl010_ids);
806
807static struct amba_driver pl010_driver = {
808 .drv = {
809 .name = "uart-pl010",
810 .pm = &pl010_dev_pm_ops,
811 },
812 .id_table = pl010_ids,
813 .probe = pl010_probe,
814 .remove = pl010_remove,
815};
816
817static int __init pl010_init(void)
818{
819 printk(KERN_INFO "Serial: AMBA driver\n");
820
821 return amba_driver_register(&pl010_driver);
822}
823
824static void __exit pl010_exit(void)
825{
826 amba_driver_unregister(&pl010_driver);
827}
828
829module_init(pl010_init);
830module_exit(pl010_exit);
831
832MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
833MODULE_DESCRIPTION("ARM AMBA serial port driver");
834MODULE_LICENSE("GPL");