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1/*
2 * Copyright (C) 2012-2015 Spreadtrum Communications Inc.
3 *
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14#if defined(CONFIG_SERIAL_SPRD_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
15#define SUPPORT_SYSRQ
16#endif
17
18#include <linux/clk.h>
19#include <linux/console.h>
20#include <linux/delay.h>
21#include <linux/io.h>
22#include <linux/ioport.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/of.h>
26#include <linux/platform_device.h>
27#include <linux/serial_core.h>
28#include <linux/serial.h>
29#include <linux/slab.h>
30#include <linux/tty.h>
31#include <linux/tty_flip.h>
32
33/* device name */
34#define UART_NR_MAX 8
35#define SPRD_TTY_NAME "ttyS"
36#define SPRD_FIFO_SIZE 128
37#define SPRD_DEF_RATE 26000000
38#define SPRD_BAUD_IO_LIMIT 3000000
39#define SPRD_TIMEOUT 256
40
41/* the offset of serial registers and BITs for them */
42/* data registers */
43#define SPRD_TXD 0x0000
44#define SPRD_RXD 0x0004
45
46/* line status register and its BITs */
47#define SPRD_LSR 0x0008
48#define SPRD_LSR_OE BIT(4)
49#define SPRD_LSR_FE BIT(3)
50#define SPRD_LSR_PE BIT(2)
51#define SPRD_LSR_BI BIT(7)
52#define SPRD_LSR_TX_OVER BIT(15)
53
54/* data number in TX and RX fifo */
55#define SPRD_STS1 0x000C
56
57/* interrupt enable register and its BITs */
58#define SPRD_IEN 0x0010
59#define SPRD_IEN_RX_FULL BIT(0)
60#define SPRD_IEN_TX_EMPTY BIT(1)
61#define SPRD_IEN_BREAK_DETECT BIT(7)
62#define SPRD_IEN_TIMEOUT BIT(13)
63
64/* interrupt clear register */
65#define SPRD_ICLR 0x0014
66
67/* line control register */
68#define SPRD_LCR 0x0018
69#define SPRD_LCR_STOP_1BIT 0x10
70#define SPRD_LCR_STOP_2BIT 0x30
71#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
72#define SPRD_LCR_DATA_LEN5 0x0
73#define SPRD_LCR_DATA_LEN6 0x4
74#define SPRD_LCR_DATA_LEN7 0x8
75#define SPRD_LCR_DATA_LEN8 0xc
76#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
77#define SPRD_LCR_PARITY_EN 0x2
78#define SPRD_LCR_EVEN_PAR 0x0
79#define SPRD_LCR_ODD_PAR 0x1
80
81/* control register 1 */
82#define SPRD_CTL1 0x001C
83#define RX_HW_FLOW_CTL_THLD BIT(6)
84#define RX_HW_FLOW_CTL_EN BIT(7)
85#define TX_HW_FLOW_CTL_EN BIT(8)
86#define RX_TOUT_THLD_DEF 0x3E00
87#define RX_HFC_THLD_DEF 0x40
88
89/* fifo threshold register */
90#define SPRD_CTL2 0x0020
91#define THLD_TX_EMPTY 0x40
92#define THLD_RX_FULL 0x40
93
94/* config baud rate register */
95#define SPRD_CLKD0 0x0024
96#define SPRD_CLKD1 0x0028
97
98/* interrupt mask status register */
99#define SPRD_IMSR 0x002C
100#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
101#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
102#define SPRD_IMSR_BREAK_DETECT BIT(7)
103#define SPRD_IMSR_TIMEOUT BIT(13)
104
105struct reg_backup {
106 u32 ien;
107 u32 ctrl0;
108 u32 ctrl1;
109 u32 ctrl2;
110 u32 clkd0;
111 u32 clkd1;
112 u32 dspwait;
113};
114
115struct sprd_uart_port {
116 struct uart_port port;
117 struct reg_backup reg_bak;
118 char name[16];
119};
120
121static struct sprd_uart_port *sprd_port[UART_NR_MAX];
122static int sprd_ports_num;
123
124static inline unsigned int serial_in(struct uart_port *port, int offset)
125{
126 return readl_relaxed(port->membase + offset);
127}
128
129static inline void serial_out(struct uart_port *port, int offset, int value)
130{
131 writel_relaxed(value, port->membase + offset);
132}
133
134static unsigned int sprd_tx_empty(struct uart_port *port)
135{
136 if (serial_in(port, SPRD_STS1) & 0xff00)
137 return 0;
138 else
139 return TIOCSER_TEMT;
140}
141
142static unsigned int sprd_get_mctrl(struct uart_port *port)
143{
144 return TIOCM_DSR | TIOCM_CTS;
145}
146
147static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
148{
149 /* nothing to do */
150}
151
152static void sprd_stop_tx(struct uart_port *port)
153{
154 unsigned int ien, iclr;
155
156 iclr = serial_in(port, SPRD_ICLR);
157 ien = serial_in(port, SPRD_IEN);
158
159 iclr |= SPRD_IEN_TX_EMPTY;
160 ien &= ~SPRD_IEN_TX_EMPTY;
161
162 serial_out(port, SPRD_ICLR, iclr);
163 serial_out(port, SPRD_IEN, ien);
164}
165
166static void sprd_start_tx(struct uart_port *port)
167{
168 unsigned int ien;
169
170 ien = serial_in(port, SPRD_IEN);
171 if (!(ien & SPRD_IEN_TX_EMPTY)) {
172 ien |= SPRD_IEN_TX_EMPTY;
173 serial_out(port, SPRD_IEN, ien);
174 }
175}
176
177static void sprd_stop_rx(struct uart_port *port)
178{
179 unsigned int ien, iclr;
180
181 iclr = serial_in(port, SPRD_ICLR);
182 ien = serial_in(port, SPRD_IEN);
183
184 ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
185 iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
186
187 serial_out(port, SPRD_IEN, ien);
188 serial_out(port, SPRD_ICLR, iclr);
189}
190
191/* The Sprd serial does not support this function. */
192static void sprd_break_ctl(struct uart_port *port, int break_state)
193{
194 /* nothing to do */
195}
196
197static int handle_lsr_errors(struct uart_port *port,
198 unsigned int *flag,
199 unsigned int *lsr)
200{
201 int ret = 0;
202
203 /* statistics */
204 if (*lsr & SPRD_LSR_BI) {
205 *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
206 port->icount.brk++;
207 ret = uart_handle_break(port);
208 if (ret)
209 return ret;
210 } else if (*lsr & SPRD_LSR_PE)
211 port->icount.parity++;
212 else if (*lsr & SPRD_LSR_FE)
213 port->icount.frame++;
214 if (*lsr & SPRD_LSR_OE)
215 port->icount.overrun++;
216
217 /* mask off conditions which should be ignored */
218 *lsr &= port->read_status_mask;
219 if (*lsr & SPRD_LSR_BI)
220 *flag = TTY_BREAK;
221 else if (*lsr & SPRD_LSR_PE)
222 *flag = TTY_PARITY;
223 else if (*lsr & SPRD_LSR_FE)
224 *flag = TTY_FRAME;
225
226 return ret;
227}
228
229static inline void sprd_rx(struct uart_port *port)
230{
231 struct tty_port *tty = &port->state->port;
232 unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
233
234 while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
235 lsr = serial_in(port, SPRD_LSR);
236 ch = serial_in(port, SPRD_RXD);
237 flag = TTY_NORMAL;
238 port->icount.rx++;
239
240 if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE |
241 SPRD_LSR_FE | SPRD_LSR_OE))
242 if (handle_lsr_errors(port, &lsr, &flag))
243 continue;
244 if (uart_handle_sysrq_char(port, ch))
245 continue;
246
247 uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
248 }
249
250 tty_flip_buffer_push(tty);
251}
252
253static inline void sprd_tx(struct uart_port *port)
254{
255 struct circ_buf *xmit = &port->state->xmit;
256 int count;
257
258 if (port->x_char) {
259 serial_out(port, SPRD_TXD, port->x_char);
260 port->icount.tx++;
261 port->x_char = 0;
262 return;
263 }
264
265 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
266 sprd_stop_tx(port);
267 return;
268 }
269
270 count = THLD_TX_EMPTY;
271 do {
272 serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
273 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
274 port->icount.tx++;
275 if (uart_circ_empty(xmit))
276 break;
277 } while (--count > 0);
278
279 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
280 uart_write_wakeup(port);
281
282 if (uart_circ_empty(xmit))
283 sprd_stop_tx(port);
284}
285
286/* this handles the interrupt from one port */
287static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
288{
289 struct uart_port *port = dev_id;
290 unsigned int ims;
291
292 spin_lock(&port->lock);
293
294 ims = serial_in(port, SPRD_IMSR);
295
296 if (!ims) {
297 spin_unlock(&port->lock);
298 return IRQ_NONE;
299 }
300
301 serial_out(port, SPRD_ICLR, ~0);
302
303 if (ims & (SPRD_IMSR_RX_FIFO_FULL |
304 SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
305 sprd_rx(port);
306
307 if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
308 sprd_tx(port);
309
310 spin_unlock(&port->lock);
311
312 return IRQ_HANDLED;
313}
314
315static int sprd_startup(struct uart_port *port)
316{
317 int ret = 0;
318 unsigned int ien, fc;
319 unsigned int timeout;
320 struct sprd_uart_port *sp;
321 unsigned long flags;
322
323 serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
324
325 /* clear rx fifo */
326 timeout = SPRD_TIMEOUT;
327 while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
328 serial_in(port, SPRD_RXD);
329
330 /* clear tx fifo */
331 timeout = SPRD_TIMEOUT;
332 while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
333 cpu_relax();
334
335 /* clear interrupt */
336 serial_out(port, SPRD_IEN, 0);
337 serial_out(port, SPRD_ICLR, ~0);
338
339 /* allocate irq */
340 sp = container_of(port, struct sprd_uart_port, port);
341 snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
342 ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
343 IRQF_SHARED, sp->name, port);
344 if (ret) {
345 dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
346 port->irq, ret);
347 return ret;
348 }
349 fc = serial_in(port, SPRD_CTL1);
350 fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
351 serial_out(port, SPRD_CTL1, fc);
352
353 /* enable interrupt */
354 spin_lock_irqsave(&port->lock, flags);
355 ien = serial_in(port, SPRD_IEN);
356 ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
357 serial_out(port, SPRD_IEN, ien);
358 spin_unlock_irqrestore(&port->lock, flags);
359
360 return 0;
361}
362
363static void sprd_shutdown(struct uart_port *port)
364{
365 serial_out(port, SPRD_IEN, 0);
366 serial_out(port, SPRD_ICLR, ~0);
367 devm_free_irq(port->dev, port->irq, port);
368}
369
370static void sprd_set_termios(struct uart_port *port,
371 struct ktermios *termios,
372 struct ktermios *old)
373{
374 unsigned int baud, quot;
375 unsigned int lcr = 0, fc;
376 unsigned long flags;
377
378 /* ask the core to calculate the divisor for us */
379 baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT);
380
381 quot = (unsigned int)((port->uartclk + baud / 2) / baud);
382
383 /* set data length */
384 switch (termios->c_cflag & CSIZE) {
385 case CS5:
386 lcr |= SPRD_LCR_DATA_LEN5;
387 break;
388 case CS6:
389 lcr |= SPRD_LCR_DATA_LEN6;
390 break;
391 case CS7:
392 lcr |= SPRD_LCR_DATA_LEN7;
393 break;
394 case CS8:
395 default:
396 lcr |= SPRD_LCR_DATA_LEN8;
397 break;
398 }
399
400 /* calculate stop bits */
401 lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
402 if (termios->c_cflag & CSTOPB)
403 lcr |= SPRD_LCR_STOP_2BIT;
404 else
405 lcr |= SPRD_LCR_STOP_1BIT;
406
407 /* calculate parity */
408 lcr &= ~SPRD_LCR_PARITY;
409 termios->c_cflag &= ~CMSPAR; /* no support mark/space */
410 if (termios->c_cflag & PARENB) {
411 lcr |= SPRD_LCR_PARITY_EN;
412 if (termios->c_cflag & PARODD)
413 lcr |= SPRD_LCR_ODD_PAR;
414 else
415 lcr |= SPRD_LCR_EVEN_PAR;
416 }
417
418 spin_lock_irqsave(&port->lock, flags);
419
420 /* update the per-port timeout */
421 uart_update_timeout(port, termios->c_cflag, baud);
422
423 port->read_status_mask = SPRD_LSR_OE;
424 if (termios->c_iflag & INPCK)
425 port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
426 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
427 port->read_status_mask |= SPRD_LSR_BI;
428
429 /* characters to ignore */
430 port->ignore_status_mask = 0;
431 if (termios->c_iflag & IGNPAR)
432 port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
433 if (termios->c_iflag & IGNBRK) {
434 port->ignore_status_mask |= SPRD_LSR_BI;
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 port->ignore_status_mask |= SPRD_LSR_OE;
441 }
442
443 /* flow control */
444 fc = serial_in(port, SPRD_CTL1);
445 fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
446 if (termios->c_cflag & CRTSCTS) {
447 fc |= RX_HW_FLOW_CTL_THLD;
448 fc |= RX_HW_FLOW_CTL_EN;
449 fc |= TX_HW_FLOW_CTL_EN;
450 }
451
452 /* clock divider bit0~bit15 */
453 serial_out(port, SPRD_CLKD0, quot & 0xffff);
454
455 /* clock divider bit16~bit20 */
456 serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
457 serial_out(port, SPRD_LCR, lcr);
458 fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
459 serial_out(port, SPRD_CTL1, fc);
460
461 spin_unlock_irqrestore(&port->lock, flags);
462
463 /* Don't rewrite B0 */
464 if (tty_termios_baud_rate(termios))
465 tty_termios_encode_baud_rate(termios, baud, baud);
466}
467
468static const char *sprd_type(struct uart_port *port)
469{
470 return "SPX";
471}
472
473static void sprd_release_port(struct uart_port *port)
474{
475 /* nothing to do */
476}
477
478static int sprd_request_port(struct uart_port *port)
479{
480 return 0;
481}
482
483static void sprd_config_port(struct uart_port *port, int flags)
484{
485 if (flags & UART_CONFIG_TYPE)
486 port->type = PORT_SPRD;
487}
488
489static int sprd_verify_port(struct uart_port *port,
490 struct serial_struct *ser)
491{
492 if (ser->type != PORT_SPRD)
493 return -EINVAL;
494 if (port->irq != ser->irq)
495 return -EINVAL;
496 if (port->iotype != ser->io_type)
497 return -EINVAL;
498 return 0;
499}
500
501static struct uart_ops serial_sprd_ops = {
502 .tx_empty = sprd_tx_empty,
503 .get_mctrl = sprd_get_mctrl,
504 .set_mctrl = sprd_set_mctrl,
505 .stop_tx = sprd_stop_tx,
506 .start_tx = sprd_start_tx,
507 .stop_rx = sprd_stop_rx,
508 .break_ctl = sprd_break_ctl,
509 .startup = sprd_startup,
510 .shutdown = sprd_shutdown,
511 .set_termios = sprd_set_termios,
512 .type = sprd_type,
513 .release_port = sprd_release_port,
514 .request_port = sprd_request_port,
515 .config_port = sprd_config_port,
516 .verify_port = sprd_verify_port,
517};
518
519#ifdef CONFIG_SERIAL_SPRD_CONSOLE
520static void wait_for_xmitr(struct uart_port *port)
521{
522 unsigned int status, tmout = 10000;
523
524 /* wait up to 10ms for the character(s) to be sent */
525 do {
526 status = serial_in(port, SPRD_STS1);
527 if (--tmout == 0)
528 break;
529 udelay(1);
530 } while (status & 0xff00);
531}
532
533static void sprd_console_putchar(struct uart_port *port, int ch)
534{
535 wait_for_xmitr(port);
536 serial_out(port, SPRD_TXD, ch);
537}
538
539static void sprd_console_write(struct console *co, const char *s,
540 unsigned int count)
541{
542 struct uart_port *port = &sprd_port[co->index]->port;
543 int locked = 1;
544 unsigned long flags;
545
546 if (port->sysrq)
547 locked = 0;
548 else if (oops_in_progress)
549 locked = spin_trylock_irqsave(&port->lock, flags);
550 else
551 spin_lock_irqsave(&port->lock, flags);
552
553 uart_console_write(port, s, count, sprd_console_putchar);
554
555 /* wait for transmitter to become empty */
556 wait_for_xmitr(port);
557
558 if (locked)
559 spin_unlock_irqrestore(&port->lock, flags);
560}
561
562static int __init sprd_console_setup(struct console *co, char *options)
563{
564 struct uart_port *port;
565 int baud = 115200;
566 int bits = 8;
567 int parity = 'n';
568 int flow = 'n';
569
570 if (co->index >= UART_NR_MAX || co->index < 0)
571 co->index = 0;
572
573 port = &sprd_port[co->index]->port;
574 if (port == NULL) {
575 pr_info("serial port %d not yet initialized\n", co->index);
576 return -ENODEV;
577 }
578 if (options)
579 uart_parse_options(options, &baud, &parity, &bits, &flow);
580
581 return uart_set_options(port, co, baud, parity, bits, flow);
582}
583
584static struct uart_driver sprd_uart_driver;
585static struct console sprd_console = {
586 .name = SPRD_TTY_NAME,
587 .write = sprd_console_write,
588 .device = uart_console_device,
589 .setup = sprd_console_setup,
590 .flags = CON_PRINTBUFFER,
591 .index = -1,
592 .data = &sprd_uart_driver,
593};
594
595#define SPRD_CONSOLE (&sprd_console)
596
597/* Support for earlycon */
598static void sprd_putc(struct uart_port *port, int c)
599{
600 unsigned int timeout = SPRD_TIMEOUT;
601
602 while (timeout-- &&
603 !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
604 cpu_relax();
605
606 writeb(c, port->membase + SPRD_TXD);
607}
608
609static void sprd_early_write(struct console *con, const char *s,
610 unsigned n)
611{
612 struct earlycon_device *dev = con->data;
613
614 uart_console_write(&dev->port, s, n, sprd_putc);
615}
616
617static int __init sprd_early_console_setup(
618 struct earlycon_device *device,
619 const char *opt)
620{
621 if (!device->port.membase)
622 return -ENODEV;
623
624 device->con->write = sprd_early_write;
625 return 0;
626}
627OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
628 sprd_early_console_setup);
629
630#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
631#define SPRD_CONSOLE NULL
632#endif
633
634static struct uart_driver sprd_uart_driver = {
635 .owner = THIS_MODULE,
636 .driver_name = "sprd_serial",
637 .dev_name = SPRD_TTY_NAME,
638 .major = 0,
639 .minor = 0,
640 .nr = UART_NR_MAX,
641 .cons = SPRD_CONSOLE,
642};
643
644static int sprd_probe_dt_alias(int index, struct device *dev)
645{
646 struct device_node *np;
647 int ret = index;
648
649 if (!IS_ENABLED(CONFIG_OF))
650 return ret;
651
652 np = dev->of_node;
653 if (!np)
654 return ret;
655
656 ret = of_alias_get_id(np, "serial");
657 if (IS_ERR_VALUE(ret))
658 ret = index;
659 else if (ret >= ARRAY_SIZE(sprd_port) || sprd_port[ret] != NULL) {
660 dev_warn(dev, "requested serial port %d not available.\n", ret);
661 ret = index;
662 }
663
664 return ret;
665}
666
667static int sprd_remove(struct platform_device *dev)
668{
669 struct sprd_uart_port *sup = platform_get_drvdata(dev);
670
671 if (sup) {
672 uart_remove_one_port(&sprd_uart_driver, &sup->port);
673 sprd_port[sup->port.line] = NULL;
674 sprd_ports_num--;
675 }
676
677 if (!sprd_ports_num)
678 uart_unregister_driver(&sprd_uart_driver);
679
680 return 0;
681}
682
683static int sprd_probe(struct platform_device *pdev)
684{
685 struct resource *res;
686 struct uart_port *up;
687 struct clk *clk;
688 int irq;
689 int index;
690 int ret;
691
692 for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
693 if (sprd_port[index] == NULL)
694 break;
695
696 if (index == ARRAY_SIZE(sprd_port))
697 return -EBUSY;
698
699 index = sprd_probe_dt_alias(index, &pdev->dev);
700
701 sprd_port[index] = devm_kzalloc(&pdev->dev,
702 sizeof(*sprd_port[index]), GFP_KERNEL);
703 if (!sprd_port[index])
704 return -ENOMEM;
705
706 up = &sprd_port[index]->port;
707 up->dev = &pdev->dev;
708 up->line = index;
709 up->type = PORT_SPRD;
710 up->iotype = UPIO_MEM;
711 up->uartclk = SPRD_DEF_RATE;
712 up->fifosize = SPRD_FIFO_SIZE;
713 up->ops = &serial_sprd_ops;
714 up->flags = UPF_BOOT_AUTOCONF;
715
716 clk = devm_clk_get(&pdev->dev, NULL);
717 if (!IS_ERR_OR_NULL(clk))
718 up->uartclk = clk_get_rate(clk);
719
720 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
721 if (!res) {
722 dev_err(&pdev->dev, "not provide mem resource\n");
723 return -ENODEV;
724 }
725 up->mapbase = res->start;
726 up->membase = devm_ioremap_resource(&pdev->dev, res);
727 if (IS_ERR(up->membase))
728 return PTR_ERR(up->membase);
729
730 irq = platform_get_irq(pdev, 0);
731 if (irq < 0) {
732 dev_err(&pdev->dev, "not provide irq resource\n");
733 return -ENODEV;
734 }
735 up->irq = irq;
736
737 if (!sprd_ports_num) {
738 ret = uart_register_driver(&sprd_uart_driver);
739 if (ret < 0) {
740 pr_err("Failed to register SPRD-UART driver\n");
741 return ret;
742 }
743 }
744 sprd_ports_num++;
745
746 ret = uart_add_one_port(&sprd_uart_driver, up);
747 if (ret) {
748 sprd_port[index] = NULL;
749 sprd_remove(pdev);
750 }
751
752 platform_set_drvdata(pdev, up);
753
754 return ret;
755}
756
757#ifdef CONFIG_PM_SLEEP
758static int sprd_suspend(struct device *dev)
759{
760 struct sprd_uart_port *sup = dev_get_drvdata(dev);
761
762 uart_suspend_port(&sprd_uart_driver, &sup->port);
763
764 return 0;
765}
766
767static int sprd_resume(struct device *dev)
768{
769 struct sprd_uart_port *sup = dev_get_drvdata(dev);
770
771 uart_resume_port(&sprd_uart_driver, &sup->port);
772
773 return 0;
774}
775#endif
776
777static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
778
779static const struct of_device_id serial_ids[] = {
780 {.compatible = "sprd,sc9836-uart",},
781 {}
782};
783MODULE_DEVICE_TABLE(of, serial_ids);
784
785static struct platform_driver sprd_platform_driver = {
786 .probe = sprd_probe,
787 .remove = sprd_remove,
788 .driver = {
789 .name = "sprd_serial",
790 .of_match_table = of_match_ptr(serial_ids),
791 .pm = &sprd_pm_ops,
792 },
793};
794
795module_platform_driver(sprd_platform_driver);
796
797MODULE_LICENSE("GPL v2");
798MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2012-2015 Spreadtrum Communications Inc.
4 */
5
6#if defined(CONFIG_SERIAL_SPRD_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
7#define SUPPORT_SYSRQ
8#endif
9
10#include <linux/clk.h>
11#include <linux/console.h>
12#include <linux/delay.h>
13#include <linux/io.h>
14#include <linux/ioport.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/serial_core.h>
20#include <linux/serial.h>
21#include <linux/slab.h>
22#include <linux/tty.h>
23#include <linux/tty_flip.h>
24
25/* device name */
26#define UART_NR_MAX 8
27#define SPRD_TTY_NAME "ttyS"
28#define SPRD_FIFO_SIZE 128
29#define SPRD_DEF_RATE 26000000
30#define SPRD_BAUD_IO_LIMIT 3000000
31#define SPRD_TIMEOUT 256000
32
33/* the offset of serial registers and BITs for them */
34/* data registers */
35#define SPRD_TXD 0x0000
36#define SPRD_RXD 0x0004
37
38/* line status register and its BITs */
39#define SPRD_LSR 0x0008
40#define SPRD_LSR_OE BIT(4)
41#define SPRD_LSR_FE BIT(3)
42#define SPRD_LSR_PE BIT(2)
43#define SPRD_LSR_BI BIT(7)
44#define SPRD_LSR_TX_OVER BIT(15)
45
46/* data number in TX and RX fifo */
47#define SPRD_STS1 0x000C
48
49/* interrupt enable register and its BITs */
50#define SPRD_IEN 0x0010
51#define SPRD_IEN_RX_FULL BIT(0)
52#define SPRD_IEN_TX_EMPTY BIT(1)
53#define SPRD_IEN_BREAK_DETECT BIT(7)
54#define SPRD_IEN_TIMEOUT BIT(13)
55
56/* interrupt clear register */
57#define SPRD_ICLR 0x0014
58#define SPRD_ICLR_TIMEOUT BIT(13)
59
60/* line control register */
61#define SPRD_LCR 0x0018
62#define SPRD_LCR_STOP_1BIT 0x10
63#define SPRD_LCR_STOP_2BIT 0x30
64#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
65#define SPRD_LCR_DATA_LEN5 0x0
66#define SPRD_LCR_DATA_LEN6 0x4
67#define SPRD_LCR_DATA_LEN7 0x8
68#define SPRD_LCR_DATA_LEN8 0xc
69#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
70#define SPRD_LCR_PARITY_EN 0x2
71#define SPRD_LCR_EVEN_PAR 0x0
72#define SPRD_LCR_ODD_PAR 0x1
73
74/* control register 1 */
75#define SPRD_CTL1 0x001C
76#define RX_HW_FLOW_CTL_THLD BIT(6)
77#define RX_HW_FLOW_CTL_EN BIT(7)
78#define TX_HW_FLOW_CTL_EN BIT(8)
79#define RX_TOUT_THLD_DEF 0x3E00
80#define RX_HFC_THLD_DEF 0x40
81
82/* fifo threshold register */
83#define SPRD_CTL2 0x0020
84#define THLD_TX_EMPTY 0x40
85#define THLD_RX_FULL 0x40
86
87/* config baud rate register */
88#define SPRD_CLKD0 0x0024
89#define SPRD_CLKD1 0x0028
90
91/* interrupt mask status register */
92#define SPRD_IMSR 0x002C
93#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
94#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
95#define SPRD_IMSR_BREAK_DETECT BIT(7)
96#define SPRD_IMSR_TIMEOUT BIT(13)
97
98struct reg_backup {
99 u32 ien;
100 u32 ctrl0;
101 u32 ctrl1;
102 u32 ctrl2;
103 u32 clkd0;
104 u32 clkd1;
105 u32 dspwait;
106};
107
108struct sprd_uart_port {
109 struct uart_port port;
110 struct reg_backup reg_bak;
111 char name[16];
112};
113
114static struct sprd_uart_port *sprd_port[UART_NR_MAX];
115static int sprd_ports_num;
116
117static inline unsigned int serial_in(struct uart_port *port, int offset)
118{
119 return readl_relaxed(port->membase + offset);
120}
121
122static inline void serial_out(struct uart_port *port, int offset, int value)
123{
124 writel_relaxed(value, port->membase + offset);
125}
126
127static unsigned int sprd_tx_empty(struct uart_port *port)
128{
129 if (serial_in(port, SPRD_STS1) & 0xff00)
130 return 0;
131 else
132 return TIOCSER_TEMT;
133}
134
135static unsigned int sprd_get_mctrl(struct uart_port *port)
136{
137 return TIOCM_DSR | TIOCM_CTS;
138}
139
140static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
141{
142 /* nothing to do */
143}
144
145static void sprd_stop_tx(struct uart_port *port)
146{
147 unsigned int ien, iclr;
148
149 iclr = serial_in(port, SPRD_ICLR);
150 ien = serial_in(port, SPRD_IEN);
151
152 iclr |= SPRD_IEN_TX_EMPTY;
153 ien &= ~SPRD_IEN_TX_EMPTY;
154
155 serial_out(port, SPRD_ICLR, iclr);
156 serial_out(port, SPRD_IEN, ien);
157}
158
159static void sprd_start_tx(struct uart_port *port)
160{
161 unsigned int ien;
162
163 ien = serial_in(port, SPRD_IEN);
164 if (!(ien & SPRD_IEN_TX_EMPTY)) {
165 ien |= SPRD_IEN_TX_EMPTY;
166 serial_out(port, SPRD_IEN, ien);
167 }
168}
169
170static void sprd_stop_rx(struct uart_port *port)
171{
172 unsigned int ien, iclr;
173
174 iclr = serial_in(port, SPRD_ICLR);
175 ien = serial_in(port, SPRD_IEN);
176
177 ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
178 iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
179
180 serial_out(port, SPRD_IEN, ien);
181 serial_out(port, SPRD_ICLR, iclr);
182}
183
184/* The Sprd serial does not support this function. */
185static void sprd_break_ctl(struct uart_port *port, int break_state)
186{
187 /* nothing to do */
188}
189
190static int handle_lsr_errors(struct uart_port *port,
191 unsigned int *flag,
192 unsigned int *lsr)
193{
194 int ret = 0;
195
196 /* statistics */
197 if (*lsr & SPRD_LSR_BI) {
198 *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
199 port->icount.brk++;
200 ret = uart_handle_break(port);
201 if (ret)
202 return ret;
203 } else if (*lsr & SPRD_LSR_PE)
204 port->icount.parity++;
205 else if (*lsr & SPRD_LSR_FE)
206 port->icount.frame++;
207 if (*lsr & SPRD_LSR_OE)
208 port->icount.overrun++;
209
210 /* mask off conditions which should be ignored */
211 *lsr &= port->read_status_mask;
212 if (*lsr & SPRD_LSR_BI)
213 *flag = TTY_BREAK;
214 else if (*lsr & SPRD_LSR_PE)
215 *flag = TTY_PARITY;
216 else if (*lsr & SPRD_LSR_FE)
217 *flag = TTY_FRAME;
218
219 return ret;
220}
221
222static inline void sprd_rx(struct uart_port *port)
223{
224 struct tty_port *tty = &port->state->port;
225 unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
226
227 while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
228 lsr = serial_in(port, SPRD_LSR);
229 ch = serial_in(port, SPRD_RXD);
230 flag = TTY_NORMAL;
231 port->icount.rx++;
232
233 if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE |
234 SPRD_LSR_FE | SPRD_LSR_OE))
235 if (handle_lsr_errors(port, &lsr, &flag))
236 continue;
237 if (uart_handle_sysrq_char(port, ch))
238 continue;
239
240 uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
241 }
242
243 tty_flip_buffer_push(tty);
244}
245
246static inline void sprd_tx(struct uart_port *port)
247{
248 struct circ_buf *xmit = &port->state->xmit;
249 int count;
250
251 if (port->x_char) {
252 serial_out(port, SPRD_TXD, port->x_char);
253 port->icount.tx++;
254 port->x_char = 0;
255 return;
256 }
257
258 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
259 sprd_stop_tx(port);
260 return;
261 }
262
263 count = THLD_TX_EMPTY;
264 do {
265 serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
266 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
267 port->icount.tx++;
268 if (uart_circ_empty(xmit))
269 break;
270 } while (--count > 0);
271
272 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
273 uart_write_wakeup(port);
274
275 if (uart_circ_empty(xmit))
276 sprd_stop_tx(port);
277}
278
279/* this handles the interrupt from one port */
280static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
281{
282 struct uart_port *port = dev_id;
283 unsigned int ims;
284
285 spin_lock(&port->lock);
286
287 ims = serial_in(port, SPRD_IMSR);
288
289 if (!ims) {
290 spin_unlock(&port->lock);
291 return IRQ_NONE;
292 }
293
294 if (ims & SPRD_IMSR_TIMEOUT)
295 serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT);
296
297 if (ims & (SPRD_IMSR_RX_FIFO_FULL |
298 SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
299 sprd_rx(port);
300
301 if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
302 sprd_tx(port);
303
304 spin_unlock(&port->lock);
305
306 return IRQ_HANDLED;
307}
308
309static int sprd_startup(struct uart_port *port)
310{
311 int ret = 0;
312 unsigned int ien, fc;
313 unsigned int timeout;
314 struct sprd_uart_port *sp;
315 unsigned long flags;
316
317 serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
318
319 /* clear rx fifo */
320 timeout = SPRD_TIMEOUT;
321 while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
322 serial_in(port, SPRD_RXD);
323
324 /* clear tx fifo */
325 timeout = SPRD_TIMEOUT;
326 while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
327 cpu_relax();
328
329 /* clear interrupt */
330 serial_out(port, SPRD_IEN, 0);
331 serial_out(port, SPRD_ICLR, ~0);
332
333 /* allocate irq */
334 sp = container_of(port, struct sprd_uart_port, port);
335 snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
336 ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
337 IRQF_SHARED, sp->name, port);
338 if (ret) {
339 dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
340 port->irq, ret);
341 return ret;
342 }
343 fc = serial_in(port, SPRD_CTL1);
344 fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
345 serial_out(port, SPRD_CTL1, fc);
346
347 /* enable interrupt */
348 spin_lock_irqsave(&port->lock, flags);
349 ien = serial_in(port, SPRD_IEN);
350 ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
351 serial_out(port, SPRD_IEN, ien);
352 spin_unlock_irqrestore(&port->lock, flags);
353
354 return 0;
355}
356
357static void sprd_shutdown(struct uart_port *port)
358{
359 serial_out(port, SPRD_IEN, 0);
360 serial_out(port, SPRD_ICLR, ~0);
361 devm_free_irq(port->dev, port->irq, port);
362}
363
364static void sprd_set_termios(struct uart_port *port,
365 struct ktermios *termios,
366 struct ktermios *old)
367{
368 unsigned int baud, quot;
369 unsigned int lcr = 0, fc;
370 unsigned long flags;
371
372 /* ask the core to calculate the divisor for us */
373 baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT);
374
375 quot = (unsigned int)((port->uartclk + baud / 2) / baud);
376
377 /* set data length */
378 switch (termios->c_cflag & CSIZE) {
379 case CS5:
380 lcr |= SPRD_LCR_DATA_LEN5;
381 break;
382 case CS6:
383 lcr |= SPRD_LCR_DATA_LEN6;
384 break;
385 case CS7:
386 lcr |= SPRD_LCR_DATA_LEN7;
387 break;
388 case CS8:
389 default:
390 lcr |= SPRD_LCR_DATA_LEN8;
391 break;
392 }
393
394 /* calculate stop bits */
395 lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
396 if (termios->c_cflag & CSTOPB)
397 lcr |= SPRD_LCR_STOP_2BIT;
398 else
399 lcr |= SPRD_LCR_STOP_1BIT;
400
401 /* calculate parity */
402 lcr &= ~SPRD_LCR_PARITY;
403 termios->c_cflag &= ~CMSPAR; /* no support mark/space */
404 if (termios->c_cflag & PARENB) {
405 lcr |= SPRD_LCR_PARITY_EN;
406 if (termios->c_cflag & PARODD)
407 lcr |= SPRD_LCR_ODD_PAR;
408 else
409 lcr |= SPRD_LCR_EVEN_PAR;
410 }
411
412 spin_lock_irqsave(&port->lock, flags);
413
414 /* update the per-port timeout */
415 uart_update_timeout(port, termios->c_cflag, baud);
416
417 port->read_status_mask = SPRD_LSR_OE;
418 if (termios->c_iflag & INPCK)
419 port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
420 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
421 port->read_status_mask |= SPRD_LSR_BI;
422
423 /* characters to ignore */
424 port->ignore_status_mask = 0;
425 if (termios->c_iflag & IGNPAR)
426 port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
427 if (termios->c_iflag & IGNBRK) {
428 port->ignore_status_mask |= SPRD_LSR_BI;
429 /*
430 * If we're ignoring parity and break indicators,
431 * ignore overruns too (for real raw support).
432 */
433 if (termios->c_iflag & IGNPAR)
434 port->ignore_status_mask |= SPRD_LSR_OE;
435 }
436
437 /* flow control */
438 fc = serial_in(port, SPRD_CTL1);
439 fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
440 if (termios->c_cflag & CRTSCTS) {
441 fc |= RX_HW_FLOW_CTL_THLD;
442 fc |= RX_HW_FLOW_CTL_EN;
443 fc |= TX_HW_FLOW_CTL_EN;
444 }
445
446 /* clock divider bit0~bit15 */
447 serial_out(port, SPRD_CLKD0, quot & 0xffff);
448
449 /* clock divider bit16~bit20 */
450 serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
451 serial_out(port, SPRD_LCR, lcr);
452 fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
453 serial_out(port, SPRD_CTL1, fc);
454
455 spin_unlock_irqrestore(&port->lock, flags);
456
457 /* Don't rewrite B0 */
458 if (tty_termios_baud_rate(termios))
459 tty_termios_encode_baud_rate(termios, baud, baud);
460}
461
462static const char *sprd_type(struct uart_port *port)
463{
464 return "SPX";
465}
466
467static void sprd_release_port(struct uart_port *port)
468{
469 /* nothing to do */
470}
471
472static int sprd_request_port(struct uart_port *port)
473{
474 return 0;
475}
476
477static void sprd_config_port(struct uart_port *port, int flags)
478{
479 if (flags & UART_CONFIG_TYPE)
480 port->type = PORT_SPRD;
481}
482
483static int sprd_verify_port(struct uart_port *port,
484 struct serial_struct *ser)
485{
486 if (ser->type != PORT_SPRD)
487 return -EINVAL;
488 if (port->irq != ser->irq)
489 return -EINVAL;
490 if (port->iotype != ser->io_type)
491 return -EINVAL;
492 return 0;
493}
494
495static const struct uart_ops serial_sprd_ops = {
496 .tx_empty = sprd_tx_empty,
497 .get_mctrl = sprd_get_mctrl,
498 .set_mctrl = sprd_set_mctrl,
499 .stop_tx = sprd_stop_tx,
500 .start_tx = sprd_start_tx,
501 .stop_rx = sprd_stop_rx,
502 .break_ctl = sprd_break_ctl,
503 .startup = sprd_startup,
504 .shutdown = sprd_shutdown,
505 .set_termios = sprd_set_termios,
506 .type = sprd_type,
507 .release_port = sprd_release_port,
508 .request_port = sprd_request_port,
509 .config_port = sprd_config_port,
510 .verify_port = sprd_verify_port,
511};
512
513#ifdef CONFIG_SERIAL_SPRD_CONSOLE
514static void wait_for_xmitr(struct uart_port *port)
515{
516 unsigned int status, tmout = 10000;
517
518 /* wait up to 10ms for the character(s) to be sent */
519 do {
520 status = serial_in(port, SPRD_STS1);
521 if (--tmout == 0)
522 break;
523 udelay(1);
524 } while (status & 0xff00);
525}
526
527static void sprd_console_putchar(struct uart_port *port, int ch)
528{
529 wait_for_xmitr(port);
530 serial_out(port, SPRD_TXD, ch);
531}
532
533static void sprd_console_write(struct console *co, const char *s,
534 unsigned int count)
535{
536 struct uart_port *port = &sprd_port[co->index]->port;
537 int locked = 1;
538 unsigned long flags;
539
540 if (port->sysrq)
541 locked = 0;
542 else if (oops_in_progress)
543 locked = spin_trylock_irqsave(&port->lock, flags);
544 else
545 spin_lock_irqsave(&port->lock, flags);
546
547 uart_console_write(port, s, count, sprd_console_putchar);
548
549 /* wait for transmitter to become empty */
550 wait_for_xmitr(port);
551
552 if (locked)
553 spin_unlock_irqrestore(&port->lock, flags);
554}
555
556static int __init sprd_console_setup(struct console *co, char *options)
557{
558 struct uart_port *port;
559 int baud = 115200;
560 int bits = 8;
561 int parity = 'n';
562 int flow = 'n';
563
564 if (co->index >= UART_NR_MAX || co->index < 0)
565 co->index = 0;
566
567 port = &sprd_port[co->index]->port;
568 if (port == NULL) {
569 pr_info("serial port %d not yet initialized\n", co->index);
570 return -ENODEV;
571 }
572 if (options)
573 uart_parse_options(options, &baud, &parity, &bits, &flow);
574
575 return uart_set_options(port, co, baud, parity, bits, flow);
576}
577
578static struct uart_driver sprd_uart_driver;
579static struct console sprd_console = {
580 .name = SPRD_TTY_NAME,
581 .write = sprd_console_write,
582 .device = uart_console_device,
583 .setup = sprd_console_setup,
584 .flags = CON_PRINTBUFFER,
585 .index = -1,
586 .data = &sprd_uart_driver,
587};
588
589#define SPRD_CONSOLE (&sprd_console)
590
591/* Support for earlycon */
592static void sprd_putc(struct uart_port *port, int c)
593{
594 unsigned int timeout = SPRD_TIMEOUT;
595
596 while (timeout-- &&
597 !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
598 cpu_relax();
599
600 writeb(c, port->membase + SPRD_TXD);
601}
602
603static void sprd_early_write(struct console *con, const char *s,
604 unsigned n)
605{
606 struct earlycon_device *dev = con->data;
607
608 uart_console_write(&dev->port, s, n, sprd_putc);
609}
610
611static int __init sprd_early_console_setup(
612 struct earlycon_device *device,
613 const char *opt)
614{
615 if (!device->port.membase)
616 return -ENODEV;
617
618 device->con->write = sprd_early_write;
619 return 0;
620}
621OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
622 sprd_early_console_setup);
623
624#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
625#define SPRD_CONSOLE NULL
626#endif
627
628static struct uart_driver sprd_uart_driver = {
629 .owner = THIS_MODULE,
630 .driver_name = "sprd_serial",
631 .dev_name = SPRD_TTY_NAME,
632 .major = 0,
633 .minor = 0,
634 .nr = UART_NR_MAX,
635 .cons = SPRD_CONSOLE,
636};
637
638static int sprd_probe_dt_alias(int index, struct device *dev)
639{
640 struct device_node *np;
641 int ret = index;
642
643 if (!IS_ENABLED(CONFIG_OF))
644 return ret;
645
646 np = dev->of_node;
647 if (!np)
648 return ret;
649
650 ret = of_alias_get_id(np, "serial");
651 if (ret < 0)
652 ret = index;
653 else if (ret >= ARRAY_SIZE(sprd_port) || sprd_port[ret] != NULL) {
654 dev_warn(dev, "requested serial port %d not available.\n", ret);
655 ret = index;
656 }
657
658 return ret;
659}
660
661static int sprd_remove(struct platform_device *dev)
662{
663 struct sprd_uart_port *sup = platform_get_drvdata(dev);
664
665 if (sup) {
666 uart_remove_one_port(&sprd_uart_driver, &sup->port);
667 sprd_port[sup->port.line] = NULL;
668 sprd_ports_num--;
669 }
670
671 if (!sprd_ports_num)
672 uart_unregister_driver(&sprd_uart_driver);
673
674 return 0;
675}
676
677static int sprd_probe(struct platform_device *pdev)
678{
679 struct resource *res;
680 struct uart_port *up;
681 struct clk *clk;
682 int irq;
683 int index;
684 int ret;
685
686 for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
687 if (sprd_port[index] == NULL)
688 break;
689
690 if (index == ARRAY_SIZE(sprd_port))
691 return -EBUSY;
692
693 index = sprd_probe_dt_alias(index, &pdev->dev);
694
695 sprd_port[index] = devm_kzalloc(&pdev->dev,
696 sizeof(*sprd_port[index]), GFP_KERNEL);
697 if (!sprd_port[index])
698 return -ENOMEM;
699
700 up = &sprd_port[index]->port;
701 up->dev = &pdev->dev;
702 up->line = index;
703 up->type = PORT_SPRD;
704 up->iotype = UPIO_MEM;
705 up->uartclk = SPRD_DEF_RATE;
706 up->fifosize = SPRD_FIFO_SIZE;
707 up->ops = &serial_sprd_ops;
708 up->flags = UPF_BOOT_AUTOCONF;
709
710 clk = devm_clk_get(&pdev->dev, NULL);
711 if (!IS_ERR_OR_NULL(clk))
712 up->uartclk = clk_get_rate(clk);
713
714 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
715 if (!res) {
716 dev_err(&pdev->dev, "not provide mem resource\n");
717 return -ENODEV;
718 }
719 up->mapbase = res->start;
720 up->membase = devm_ioremap_resource(&pdev->dev, res);
721 if (IS_ERR(up->membase))
722 return PTR_ERR(up->membase);
723
724 irq = platform_get_irq(pdev, 0);
725 if (irq < 0) {
726 dev_err(&pdev->dev, "not provide irq resource: %d\n", irq);
727 return irq;
728 }
729 up->irq = irq;
730
731 if (!sprd_ports_num) {
732 ret = uart_register_driver(&sprd_uart_driver);
733 if (ret < 0) {
734 pr_err("Failed to register SPRD-UART driver\n");
735 return ret;
736 }
737 }
738 sprd_ports_num++;
739
740 ret = uart_add_one_port(&sprd_uart_driver, up);
741 if (ret) {
742 sprd_port[index] = NULL;
743 sprd_remove(pdev);
744 }
745
746 platform_set_drvdata(pdev, up);
747
748 return ret;
749}
750
751#ifdef CONFIG_PM_SLEEP
752static int sprd_suspend(struct device *dev)
753{
754 struct sprd_uart_port *sup = dev_get_drvdata(dev);
755
756 uart_suspend_port(&sprd_uart_driver, &sup->port);
757
758 return 0;
759}
760
761static int sprd_resume(struct device *dev)
762{
763 struct sprd_uart_port *sup = dev_get_drvdata(dev);
764
765 uart_resume_port(&sprd_uart_driver, &sup->port);
766
767 return 0;
768}
769#endif
770
771static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
772
773static const struct of_device_id serial_ids[] = {
774 {.compatible = "sprd,sc9836-uart",},
775 {}
776};
777MODULE_DEVICE_TABLE(of, serial_ids);
778
779static struct platform_driver sprd_platform_driver = {
780 .probe = sprd_probe,
781 .remove = sprd_remove,
782 .driver = {
783 .name = "sprd_serial",
784 .of_match_table = of_match_ptr(serial_ids),
785 .pm = &sprd_pm_ops,
786 },
787};
788
789module_platform_driver(sprd_platform_driver);
790
791MODULE_LICENSE("GPL v2");
792MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");