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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based on meson_uart.c, by AMLOGIC, INC.
4 *
5 * Copyright (C) 2014 Carlo Caione <carlo@caione.org>
6 */
7
8#include <linux/clk.h>
9#include <linux/console.h>
10#include <linux/delay.h>
11#include <linux/init.h>
12#include <linux/io.h>
13#include <linux/iopoll.h>
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/serial.h>
19#include <linux/serial_core.h>
20#include <linux/tty.h>
21#include <linux/tty_flip.h>
22
23/* Register offsets */
24#define AML_UART_WFIFO 0x00
25#define AML_UART_RFIFO 0x04
26#define AML_UART_CONTROL 0x08
27#define AML_UART_STATUS 0x0c
28#define AML_UART_MISC 0x10
29#define AML_UART_REG5 0x14
30
31/* AML_UART_CONTROL bits */
32#define AML_UART_TX_EN BIT(12)
33#define AML_UART_RX_EN BIT(13)
34#define AML_UART_TWO_WIRE_EN BIT(15)
35#define AML_UART_STOP_BIT_LEN_MASK (0x03 << 16)
36#define AML_UART_STOP_BIT_1SB (0x00 << 16)
37#define AML_UART_STOP_BIT_2SB (0x01 << 16)
38#define AML_UART_PARITY_TYPE BIT(18)
39#define AML_UART_PARITY_EN BIT(19)
40#define AML_UART_TX_RST BIT(22)
41#define AML_UART_RX_RST BIT(23)
42#define AML_UART_CLEAR_ERR BIT(24)
43#define AML_UART_RX_INT_EN BIT(27)
44#define AML_UART_TX_INT_EN BIT(28)
45#define AML_UART_DATA_LEN_MASK (0x03 << 20)
46#define AML_UART_DATA_LEN_8BIT (0x00 << 20)
47#define AML_UART_DATA_LEN_7BIT (0x01 << 20)
48#define AML_UART_DATA_LEN_6BIT (0x02 << 20)
49#define AML_UART_DATA_LEN_5BIT (0x03 << 20)
50
51/* AML_UART_STATUS bits */
52#define AML_UART_PARITY_ERR BIT(16)
53#define AML_UART_FRAME_ERR BIT(17)
54#define AML_UART_TX_FIFO_WERR BIT(18)
55#define AML_UART_RX_EMPTY BIT(20)
56#define AML_UART_TX_FULL BIT(21)
57#define AML_UART_TX_EMPTY BIT(22)
58#define AML_UART_XMIT_BUSY BIT(25)
59#define AML_UART_ERR (AML_UART_PARITY_ERR | \
60 AML_UART_FRAME_ERR | \
61 AML_UART_TX_FIFO_WERR)
62
63/* AML_UART_MISC bits */
64#define AML_UART_XMIT_IRQ(c) (((c) & 0xff) << 8)
65#define AML_UART_RECV_IRQ(c) ((c) & 0xff)
66
67/* AML_UART_REG5 bits */
68#define AML_UART_BAUD_MASK 0x7fffff
69#define AML_UART_BAUD_USE BIT(23)
70#define AML_UART_BAUD_XTAL BIT(24)
71#define AML_UART_BAUD_XTAL_DIV2 BIT(27)
72
73#define AML_UART_PORT_NUM 12
74#define AML_UART_PORT_OFFSET 6
75
76#define AML_UART_POLL_USEC 5
77#define AML_UART_TIMEOUT_USEC 10000
78
79static struct uart_driver meson_uart_driver_ttyAML;
80static struct uart_driver meson_uart_driver_ttyS;
81
82static struct uart_port *meson_ports[AML_UART_PORT_NUM];
83
84struct meson_uart_data {
85 struct uart_driver *uart_driver;
86 bool has_xtal_div2;
87};
88
89static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
90{
91}
92
93static unsigned int meson_uart_get_mctrl(struct uart_port *port)
94{
95 return TIOCM_CTS;
96}
97
98static unsigned int meson_uart_tx_empty(struct uart_port *port)
99{
100 u32 val;
101
102 val = readl(port->membase + AML_UART_STATUS);
103 val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY);
104 return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0;
105}
106
107static void meson_uart_stop_tx(struct uart_port *port)
108{
109 u32 val;
110
111 val = readl(port->membase + AML_UART_CONTROL);
112 val &= ~AML_UART_TX_INT_EN;
113 writel(val, port->membase + AML_UART_CONTROL);
114}
115
116static void meson_uart_stop_rx(struct uart_port *port)
117{
118 u32 val;
119
120 val = readl(port->membase + AML_UART_CONTROL);
121 val &= ~AML_UART_RX_EN;
122 writel(val, port->membase + AML_UART_CONTROL);
123}
124
125static void meson_uart_shutdown(struct uart_port *port)
126{
127 unsigned long flags;
128 u32 val;
129
130 free_irq(port->irq, port);
131
132 uart_port_lock_irqsave(port, &flags);
133
134 val = readl(port->membase + AML_UART_CONTROL);
135 val &= ~AML_UART_RX_EN;
136 val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
137 writel(val, port->membase + AML_UART_CONTROL);
138
139 uart_port_unlock_irqrestore(port, flags);
140}
141
142static void meson_uart_start_tx(struct uart_port *port)
143{
144 struct circ_buf *xmit = &port->state->xmit;
145 unsigned int ch;
146 u32 val;
147
148 if (uart_tx_stopped(port)) {
149 meson_uart_stop_tx(port);
150 return;
151 }
152
153 while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
154 if (port->x_char) {
155 writel(port->x_char, port->membase + AML_UART_WFIFO);
156 port->icount.tx++;
157 port->x_char = 0;
158 continue;
159 }
160
161 if (uart_circ_empty(xmit))
162 break;
163
164 ch = xmit->buf[xmit->tail];
165 writel(ch, port->membase + AML_UART_WFIFO);
166 uart_xmit_advance(port, 1);
167 }
168
169 if (!uart_circ_empty(xmit)) {
170 val = readl(port->membase + AML_UART_CONTROL);
171 val |= AML_UART_TX_INT_EN;
172 writel(val, port->membase + AML_UART_CONTROL);
173 }
174
175 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
176 uart_write_wakeup(port);
177}
178
179static void meson_receive_chars(struct uart_port *port)
180{
181 struct tty_port *tport = &port->state->port;
182 char flag;
183 u32 ostatus, status, ch, mode;
184
185 do {
186 flag = TTY_NORMAL;
187 port->icount.rx++;
188 ostatus = status = readl(port->membase + AML_UART_STATUS);
189
190 if (status & AML_UART_ERR) {
191 if (status & AML_UART_TX_FIFO_WERR)
192 port->icount.overrun++;
193 else if (status & AML_UART_FRAME_ERR)
194 port->icount.frame++;
195 else if (status & AML_UART_PARITY_ERR)
196 port->icount.frame++;
197
198 mode = readl(port->membase + AML_UART_CONTROL);
199 mode |= AML_UART_CLEAR_ERR;
200 writel(mode, port->membase + AML_UART_CONTROL);
201
202 /* It doesn't clear to 0 automatically */
203 mode &= ~AML_UART_CLEAR_ERR;
204 writel(mode, port->membase + AML_UART_CONTROL);
205
206 status &= port->read_status_mask;
207 if (status & AML_UART_FRAME_ERR)
208 flag = TTY_FRAME;
209 else if (status & AML_UART_PARITY_ERR)
210 flag = TTY_PARITY;
211 }
212
213 ch = readl(port->membase + AML_UART_RFIFO);
214 ch &= 0xff;
215
216 if ((ostatus & AML_UART_FRAME_ERR) && (ch == 0)) {
217 port->icount.brk++;
218 flag = TTY_BREAK;
219 if (uart_handle_break(port))
220 continue;
221 }
222
223 if (uart_handle_sysrq_char(port, ch))
224 continue;
225
226 if ((status & port->ignore_status_mask) == 0)
227 tty_insert_flip_char(tport, ch, flag);
228
229 if (status & AML_UART_TX_FIFO_WERR)
230 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
231
232 } while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY));
233
234 tty_flip_buffer_push(tport);
235}
236
237static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
238{
239 struct uart_port *port = (struct uart_port *)dev_id;
240
241 uart_port_lock(port);
242
243 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
244 meson_receive_chars(port);
245
246 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
247 if (readl(port->membase + AML_UART_CONTROL) & AML_UART_TX_INT_EN)
248 meson_uart_start_tx(port);
249 }
250
251 uart_port_unlock(port);
252
253 return IRQ_HANDLED;
254}
255
256static const char *meson_uart_type(struct uart_port *port)
257{
258 return (port->type == PORT_MESON) ? "meson_uart" : NULL;
259}
260
261/*
262 * This function is called only from probe() using a temporary io mapping
263 * in order to perform a reset before setting up the device. Since the
264 * temporarily mapped region was successfully requested, there can be no
265 * console on this port at this time. Hence it is not necessary for this
266 * function to acquire the port->lock. (Since there is no console on this
267 * port at this time, the port->lock is not initialized yet.)
268 */
269static void meson_uart_reset(struct uart_port *port)
270{
271 u32 val;
272
273 val = readl(port->membase + AML_UART_CONTROL);
274 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
275 writel(val, port->membase + AML_UART_CONTROL);
276
277 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
278 writel(val, port->membase + AML_UART_CONTROL);
279}
280
281static int meson_uart_startup(struct uart_port *port)
282{
283 unsigned long flags;
284 u32 val;
285 int ret = 0;
286
287 uart_port_lock_irqsave(port, &flags);
288
289 val = readl(port->membase + AML_UART_CONTROL);
290 val |= AML_UART_CLEAR_ERR;
291 writel(val, port->membase + AML_UART_CONTROL);
292 val &= ~AML_UART_CLEAR_ERR;
293 writel(val, port->membase + AML_UART_CONTROL);
294
295 val |= (AML_UART_RX_EN | AML_UART_TX_EN);
296 writel(val, port->membase + AML_UART_CONTROL);
297
298 val |= (AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
299 writel(val, port->membase + AML_UART_CONTROL);
300
301 val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2));
302 writel(val, port->membase + AML_UART_MISC);
303
304 uart_port_unlock_irqrestore(port, flags);
305
306 ret = request_irq(port->irq, meson_uart_interrupt, 0,
307 port->name, port);
308
309 return ret;
310}
311
312static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
313{
314 const struct meson_uart_data *private_data = port->private_data;
315 u32 val = 0;
316
317 while (!meson_uart_tx_empty(port))
318 cpu_relax();
319
320 if (port->uartclk == 24000000) {
321 unsigned int xtal_div = 3;
322
323 if (private_data && private_data->has_xtal_div2) {
324 xtal_div = 2;
325 val |= AML_UART_BAUD_XTAL_DIV2;
326 }
327 val |= DIV_ROUND_CLOSEST(port->uartclk / xtal_div, baud) - 1;
328 val |= AML_UART_BAUD_XTAL;
329 } else {
330 val = DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1;
331 }
332 val |= AML_UART_BAUD_USE;
333 writel(val, port->membase + AML_UART_REG5);
334}
335
336static void meson_uart_set_termios(struct uart_port *port,
337 struct ktermios *termios,
338 const struct ktermios *old)
339{
340 unsigned int cflags, iflags, baud;
341 unsigned long flags;
342 u32 val;
343
344 uart_port_lock_irqsave(port, &flags);
345
346 cflags = termios->c_cflag;
347 iflags = termios->c_iflag;
348
349 val = readl(port->membase + AML_UART_CONTROL);
350
351 val &= ~AML_UART_DATA_LEN_MASK;
352 switch (cflags & CSIZE) {
353 case CS8:
354 val |= AML_UART_DATA_LEN_8BIT;
355 break;
356 case CS7:
357 val |= AML_UART_DATA_LEN_7BIT;
358 break;
359 case CS6:
360 val |= AML_UART_DATA_LEN_6BIT;
361 break;
362 case CS5:
363 val |= AML_UART_DATA_LEN_5BIT;
364 break;
365 }
366
367 if (cflags & PARENB)
368 val |= AML_UART_PARITY_EN;
369 else
370 val &= ~AML_UART_PARITY_EN;
371
372 if (cflags & PARODD)
373 val |= AML_UART_PARITY_TYPE;
374 else
375 val &= ~AML_UART_PARITY_TYPE;
376
377 val &= ~AML_UART_STOP_BIT_LEN_MASK;
378 if (cflags & CSTOPB)
379 val |= AML_UART_STOP_BIT_2SB;
380 else
381 val |= AML_UART_STOP_BIT_1SB;
382
383 if (cflags & CRTSCTS) {
384 if (port->flags & UPF_HARD_FLOW)
385 val &= ~AML_UART_TWO_WIRE_EN;
386 else
387 termios->c_cflag &= ~CRTSCTS;
388 } else {
389 val |= AML_UART_TWO_WIRE_EN;
390 }
391
392 writel(val, port->membase + AML_UART_CONTROL);
393
394 baud = uart_get_baud_rate(port, termios, old, 50, 4000000);
395 meson_uart_change_speed(port, baud);
396
397 port->read_status_mask = AML_UART_TX_FIFO_WERR;
398 if (iflags & INPCK)
399 port->read_status_mask |= AML_UART_PARITY_ERR |
400 AML_UART_FRAME_ERR;
401
402 port->ignore_status_mask = 0;
403 if (iflags & IGNPAR)
404 port->ignore_status_mask |= AML_UART_PARITY_ERR |
405 AML_UART_FRAME_ERR;
406
407 uart_update_timeout(port, termios->c_cflag, baud);
408 uart_port_unlock_irqrestore(port, flags);
409}
410
411static int meson_uart_verify_port(struct uart_port *port,
412 struct serial_struct *ser)
413{
414 int ret = 0;
415
416 if (port->type != PORT_MESON)
417 ret = -EINVAL;
418 if (port->irq != ser->irq)
419 ret = -EINVAL;
420 if (ser->baud_base < 9600)
421 ret = -EINVAL;
422 return ret;
423}
424
425static void meson_uart_release_port(struct uart_port *port)
426{
427 devm_iounmap(port->dev, port->membase);
428 port->membase = NULL;
429 devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
430}
431
432static int meson_uart_request_port(struct uart_port *port)
433{
434 if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
435 dev_name(port->dev))) {
436 dev_err(port->dev, "Memory region busy\n");
437 return -EBUSY;
438 }
439
440 port->membase = devm_ioremap(port->dev, port->mapbase,
441 port->mapsize);
442 if (!port->membase)
443 return -ENOMEM;
444
445 return 0;
446}
447
448static void meson_uart_config_port(struct uart_port *port, int flags)
449{
450 if (flags & UART_CONFIG_TYPE) {
451 port->type = PORT_MESON;
452 meson_uart_request_port(port);
453 }
454}
455
456#ifdef CONFIG_CONSOLE_POLL
457/*
458 * Console polling routines for writing and reading from the uart while
459 * in an interrupt or debug context (i.e. kgdb).
460 */
461
462static int meson_uart_poll_get_char(struct uart_port *port)
463{
464 u32 c;
465 unsigned long flags;
466
467 uart_port_lock_irqsave(port, &flags);
468
469 if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
470 c = NO_POLL_CHAR;
471 else
472 c = readl(port->membase + AML_UART_RFIFO);
473
474 uart_port_unlock_irqrestore(port, flags);
475
476 return c;
477}
478
479static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
480{
481 unsigned long flags;
482 u32 reg;
483 int ret;
484
485 uart_port_lock_irqsave(port, &flags);
486
487 /* Wait until FIFO is empty or timeout */
488 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
489 reg & AML_UART_TX_EMPTY,
490 AML_UART_POLL_USEC,
491 AML_UART_TIMEOUT_USEC);
492 if (ret == -ETIMEDOUT) {
493 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
494 goto out;
495 }
496
497 /* Write the character */
498 writel(c, port->membase + AML_UART_WFIFO);
499
500 /* Wait until FIFO is empty or timeout */
501 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
502 reg & AML_UART_TX_EMPTY,
503 AML_UART_POLL_USEC,
504 AML_UART_TIMEOUT_USEC);
505 if (ret == -ETIMEDOUT)
506 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
507
508out:
509 uart_port_unlock_irqrestore(port, flags);
510}
511
512#endif /* CONFIG_CONSOLE_POLL */
513
514static const struct uart_ops meson_uart_ops = {
515 .set_mctrl = meson_uart_set_mctrl,
516 .get_mctrl = meson_uart_get_mctrl,
517 .tx_empty = meson_uart_tx_empty,
518 .start_tx = meson_uart_start_tx,
519 .stop_tx = meson_uart_stop_tx,
520 .stop_rx = meson_uart_stop_rx,
521 .startup = meson_uart_startup,
522 .shutdown = meson_uart_shutdown,
523 .set_termios = meson_uart_set_termios,
524 .type = meson_uart_type,
525 .config_port = meson_uart_config_port,
526 .request_port = meson_uart_request_port,
527 .release_port = meson_uart_release_port,
528 .verify_port = meson_uart_verify_port,
529#ifdef CONFIG_CONSOLE_POLL
530 .poll_get_char = meson_uart_poll_get_char,
531 .poll_put_char = meson_uart_poll_put_char,
532#endif
533};
534
535#ifdef CONFIG_SERIAL_MESON_CONSOLE
536static void meson_uart_enable_tx_engine(struct uart_port *port)
537{
538 u32 val;
539
540 val = readl(port->membase + AML_UART_CONTROL);
541 val |= AML_UART_TX_EN;
542 writel(val, port->membase + AML_UART_CONTROL);
543}
544
545static void meson_console_putchar(struct uart_port *port, unsigned char ch)
546{
547 if (!port->membase)
548 return;
549
550 while (readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)
551 cpu_relax();
552 writel(ch, port->membase + AML_UART_WFIFO);
553}
554
555static void meson_serial_port_write(struct uart_port *port, const char *s,
556 u_int count)
557{
558 unsigned long flags;
559 int locked;
560 u32 val, tmp;
561
562 local_irq_save(flags);
563 if (port->sysrq) {
564 locked = 0;
565 } else if (oops_in_progress) {
566 locked = uart_port_trylock(port);
567 } else {
568 uart_port_lock(port);
569 locked = 1;
570 }
571
572 val = readl(port->membase + AML_UART_CONTROL);
573 tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
574 writel(tmp, port->membase + AML_UART_CONTROL);
575
576 uart_console_write(port, s, count, meson_console_putchar);
577 writel(val, port->membase + AML_UART_CONTROL);
578
579 if (locked)
580 uart_port_unlock(port);
581 local_irq_restore(flags);
582}
583
584static void meson_serial_console_write(struct console *co, const char *s,
585 u_int count)
586{
587 struct uart_port *port;
588
589 port = meson_ports[co->index];
590 if (!port)
591 return;
592
593 meson_serial_port_write(port, s, count);
594}
595
596static int meson_serial_console_setup(struct console *co, char *options)
597{
598 struct uart_port *port;
599 int baud = 115200;
600 int bits = 8;
601 int parity = 'n';
602 int flow = 'n';
603
604 if (co->index < 0 || co->index >= AML_UART_PORT_NUM)
605 return -EINVAL;
606
607 port = meson_ports[co->index];
608 if (!port || !port->membase)
609 return -ENODEV;
610
611 meson_uart_enable_tx_engine(port);
612
613 if (options)
614 uart_parse_options(options, &baud, &parity, &bits, &flow);
615
616 return uart_set_options(port, co, baud, parity, bits, flow);
617}
618
619#define MESON_SERIAL_CONSOLE(_devname) \
620 static struct console meson_serial_console_##_devname = { \
621 .name = __stringify(_devname), \
622 .write = meson_serial_console_write, \
623 .device = uart_console_device, \
624 .setup = meson_serial_console_setup, \
625 .flags = CON_PRINTBUFFER, \
626 .index = -1, \
627 .data = &meson_uart_driver_##_devname, \
628 }
629
630MESON_SERIAL_CONSOLE(ttyAML);
631MESON_SERIAL_CONSOLE(ttyS);
632
633static void meson_serial_early_console_write(struct console *co,
634 const char *s,
635 u_int count)
636{
637 struct earlycon_device *dev = co->data;
638
639 meson_serial_port_write(&dev->port, s, count);
640}
641
642static int __init
643meson_serial_early_console_setup(struct earlycon_device *device, const char *opt)
644{
645 if (!device->port.membase)
646 return -ENODEV;
647
648 meson_uart_enable_tx_engine(&device->port);
649 device->con->write = meson_serial_early_console_write;
650 return 0;
651}
652
653OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart", meson_serial_early_console_setup);
654OF_EARLYCON_DECLARE(meson, "amlogic,meson-s4-uart", meson_serial_early_console_setup);
655
656#define MESON_SERIAL_CONSOLE_PTR(_devname) (&meson_serial_console_##_devname)
657#else
658#define MESON_SERIAL_CONSOLE_PTR(_devname) (NULL)
659#endif
660
661#define MESON_UART_DRIVER(_devname) \
662 static struct uart_driver meson_uart_driver_##_devname = { \
663 .owner = THIS_MODULE, \
664 .driver_name = "meson_uart", \
665 .dev_name = __stringify(_devname), \
666 .nr = AML_UART_PORT_NUM, \
667 .cons = MESON_SERIAL_CONSOLE_PTR(_devname), \
668 }
669
670MESON_UART_DRIVER(ttyAML);
671MESON_UART_DRIVER(ttyS);
672
673static int meson_uart_probe_clocks(struct platform_device *pdev,
674 struct uart_port *port)
675{
676 struct clk *clk_xtal = NULL;
677 struct clk *clk_pclk = NULL;
678 struct clk *clk_baud = NULL;
679
680 clk_pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
681 if (IS_ERR(clk_pclk))
682 return PTR_ERR(clk_pclk);
683
684 clk_xtal = devm_clk_get_enabled(&pdev->dev, "xtal");
685 if (IS_ERR(clk_xtal))
686 return PTR_ERR(clk_xtal);
687
688 clk_baud = devm_clk_get_enabled(&pdev->dev, "baud");
689 if (IS_ERR(clk_baud))
690 return PTR_ERR(clk_baud);
691
692 port->uartclk = clk_get_rate(clk_baud);
693
694 return 0;
695}
696
697static struct uart_driver *meson_uart_current(const struct meson_uart_data *pd)
698{
699 return (pd && pd->uart_driver) ?
700 pd->uart_driver : &meson_uart_driver_ttyAML;
701}
702
703static int meson_uart_probe(struct platform_device *pdev)
704{
705 const struct meson_uart_data *priv_data;
706 struct uart_driver *uart_driver;
707 struct resource *res_mem;
708 struct uart_port *port;
709 u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
710 int ret = 0;
711 int irq;
712 bool has_rtscts;
713
714 if (pdev->dev.of_node)
715 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
716
717 if (pdev->id < 0) {
718 int id;
719
720 for (id = AML_UART_PORT_OFFSET; id < AML_UART_PORT_NUM; id++) {
721 if (!meson_ports[id]) {
722 pdev->id = id;
723 break;
724 }
725 }
726 }
727
728 if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM)
729 return -EINVAL;
730
731 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
732 if (!res_mem)
733 return -ENODEV;
734
735 irq = platform_get_irq(pdev, 0);
736 if (irq < 0)
737 return irq;
738
739 of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
740 has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts");
741
742 if (meson_ports[pdev->id]) {
743 return dev_err_probe(&pdev->dev, -EBUSY,
744 "port %d already allocated\n", pdev->id);
745 }
746
747 port = devm_kzalloc(&pdev->dev, sizeof(struct uart_port), GFP_KERNEL);
748 if (!port)
749 return -ENOMEM;
750
751 ret = meson_uart_probe_clocks(pdev, port);
752 if (ret)
753 return ret;
754
755 priv_data = device_get_match_data(&pdev->dev);
756
757 uart_driver = meson_uart_current(priv_data);
758
759 if (!uart_driver->state) {
760 ret = uart_register_driver(uart_driver);
761 if (ret)
762 return dev_err_probe(&pdev->dev, ret,
763 "can't register uart driver\n");
764 }
765
766 port->iotype = UPIO_MEM;
767 port->mapbase = res_mem->start;
768 port->mapsize = resource_size(res_mem);
769 port->irq = irq;
770 port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
771 if (has_rtscts)
772 port->flags |= UPF_HARD_FLOW;
773 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
774 port->dev = &pdev->dev;
775 port->line = pdev->id;
776 port->type = PORT_MESON;
777 port->x_char = 0;
778 port->ops = &meson_uart_ops;
779 port->fifosize = fifosize;
780 port->private_data = (void *)priv_data;
781
782 meson_ports[pdev->id] = port;
783 platform_set_drvdata(pdev, port);
784
785 /* reset port before registering (and possibly registering console) */
786 if (meson_uart_request_port(port) >= 0) {
787 meson_uart_reset(port);
788 meson_uart_release_port(port);
789 }
790
791 ret = uart_add_one_port(uart_driver, port);
792 if (ret)
793 meson_ports[pdev->id] = NULL;
794
795 return ret;
796}
797
798static void meson_uart_remove(struct platform_device *pdev)
799{
800 struct uart_driver *uart_driver;
801 struct uart_port *port;
802
803 port = platform_get_drvdata(pdev);
804 uart_driver = meson_uart_current(port->private_data);
805 uart_remove_one_port(uart_driver, port);
806 meson_ports[pdev->id] = NULL;
807
808 for (int id = 0; id < AML_UART_PORT_NUM; id++)
809 if (meson_ports[id])
810 return;
811
812 /* No more available uart ports, unregister uart driver */
813 uart_unregister_driver(uart_driver);
814}
815
816static struct meson_uart_data meson_g12a_uart_data = {
817 .has_xtal_div2 = true,
818};
819
820static struct meson_uart_data meson_a1_uart_data = {
821 .uart_driver = &meson_uart_driver_ttyS,
822 .has_xtal_div2 = false,
823};
824
825static struct meson_uart_data meson_s4_uart_data = {
826 .uart_driver = &meson_uart_driver_ttyS,
827 .has_xtal_div2 = true,
828};
829
830static const struct of_device_id meson_uart_dt_match[] = {
831 { .compatible = "amlogic,meson6-uart" },
832 { .compatible = "amlogic,meson8-uart" },
833 { .compatible = "amlogic,meson8b-uart" },
834 { .compatible = "amlogic,meson-gx-uart" },
835 {
836 .compatible = "amlogic,meson-g12a-uart",
837 .data = (void *)&meson_g12a_uart_data,
838 },
839 {
840 .compatible = "amlogic,meson-s4-uart",
841 .data = (void *)&meson_s4_uart_data,
842 },
843 {
844 .compatible = "amlogic,meson-a1-uart",
845 .data = (void *)&meson_a1_uart_data,
846 },
847 { /* sentinel */ },
848};
849MODULE_DEVICE_TABLE(of, meson_uart_dt_match);
850
851static struct platform_driver meson_uart_platform_driver = {
852 .probe = meson_uart_probe,
853 .remove_new = meson_uart_remove,
854 .driver = {
855 .name = "meson_uart",
856 .of_match_table = meson_uart_dt_match,
857 },
858};
859
860module_platform_driver(meson_uart_platform_driver);
861
862MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
863MODULE_DESCRIPTION("Amlogic Meson serial port driver");
864MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based on meson_uart.c, by AMLOGIC, INC.
4 *
5 * Copyright (C) 2014 Carlo Caione <carlo@caione.org>
6 */
7
8#include <linux/clk.h>
9#include <linux/console.h>
10#include <linux/delay.h>
11#include <linux/init.h>
12#include <linux/io.h>
13#include <linux/iopoll.h>
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/serial.h>
19#include <linux/serial_core.h>
20#include <linux/tty.h>
21#include <linux/tty_flip.h>
22
23/* Register offsets */
24#define AML_UART_WFIFO 0x00
25#define AML_UART_RFIFO 0x04
26#define AML_UART_CONTROL 0x08
27#define AML_UART_STATUS 0x0c
28#define AML_UART_MISC 0x10
29#define AML_UART_REG5 0x14
30
31/* AML_UART_CONTROL bits */
32#define AML_UART_TX_EN BIT(12)
33#define AML_UART_RX_EN BIT(13)
34#define AML_UART_TWO_WIRE_EN BIT(15)
35#define AML_UART_STOP_BIT_LEN_MASK (0x03 << 16)
36#define AML_UART_STOP_BIT_1SB (0x00 << 16)
37#define AML_UART_STOP_BIT_2SB (0x01 << 16)
38#define AML_UART_PARITY_TYPE BIT(18)
39#define AML_UART_PARITY_EN BIT(19)
40#define AML_UART_TX_RST BIT(22)
41#define AML_UART_RX_RST BIT(23)
42#define AML_UART_CLEAR_ERR BIT(24)
43#define AML_UART_RX_INT_EN BIT(27)
44#define AML_UART_TX_INT_EN BIT(28)
45#define AML_UART_DATA_LEN_MASK (0x03 << 20)
46#define AML_UART_DATA_LEN_8BIT (0x00 << 20)
47#define AML_UART_DATA_LEN_7BIT (0x01 << 20)
48#define AML_UART_DATA_LEN_6BIT (0x02 << 20)
49#define AML_UART_DATA_LEN_5BIT (0x03 << 20)
50
51/* AML_UART_STATUS bits */
52#define AML_UART_PARITY_ERR BIT(16)
53#define AML_UART_FRAME_ERR BIT(17)
54#define AML_UART_TX_FIFO_WERR BIT(18)
55#define AML_UART_RX_EMPTY BIT(20)
56#define AML_UART_TX_FULL BIT(21)
57#define AML_UART_TX_EMPTY BIT(22)
58#define AML_UART_XMIT_BUSY BIT(25)
59#define AML_UART_ERR (AML_UART_PARITY_ERR | \
60 AML_UART_FRAME_ERR | \
61 AML_UART_TX_FIFO_WERR)
62
63/* AML_UART_MISC bits */
64#define AML_UART_XMIT_IRQ(c) (((c) & 0xff) << 8)
65#define AML_UART_RECV_IRQ(c) ((c) & 0xff)
66
67/* AML_UART_REG5 bits */
68#define AML_UART_BAUD_MASK 0x7fffff
69#define AML_UART_BAUD_USE BIT(23)
70#define AML_UART_BAUD_XTAL BIT(24)
71
72#define AML_UART_PORT_NUM 12
73#define AML_UART_PORT_OFFSET 6
74#define AML_UART_DEV_NAME "ttyAML"
75
76#define AML_UART_POLL_USEC 5
77#define AML_UART_TIMEOUT_USEC 10000
78
79static struct uart_driver meson_uart_driver;
80
81static struct uart_port *meson_ports[AML_UART_PORT_NUM];
82
83static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
84{
85}
86
87static unsigned int meson_uart_get_mctrl(struct uart_port *port)
88{
89 return TIOCM_CTS;
90}
91
92static unsigned int meson_uart_tx_empty(struct uart_port *port)
93{
94 u32 val;
95
96 val = readl(port->membase + AML_UART_STATUS);
97 val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY);
98 return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0;
99}
100
101static void meson_uart_stop_tx(struct uart_port *port)
102{
103 u32 val;
104
105 val = readl(port->membase + AML_UART_CONTROL);
106 val &= ~AML_UART_TX_INT_EN;
107 writel(val, port->membase + AML_UART_CONTROL);
108}
109
110static void meson_uart_stop_rx(struct uart_port *port)
111{
112 u32 val;
113
114 val = readl(port->membase + AML_UART_CONTROL);
115 val &= ~AML_UART_RX_EN;
116 writel(val, port->membase + AML_UART_CONTROL);
117}
118
119static void meson_uart_shutdown(struct uart_port *port)
120{
121 unsigned long flags;
122 u32 val;
123
124 free_irq(port->irq, port);
125
126 spin_lock_irqsave(&port->lock, flags);
127
128 val = readl(port->membase + AML_UART_CONTROL);
129 val &= ~AML_UART_RX_EN;
130 val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
131 writel(val, port->membase + AML_UART_CONTROL);
132
133 spin_unlock_irqrestore(&port->lock, flags);
134}
135
136static void meson_uart_start_tx(struct uart_port *port)
137{
138 struct circ_buf *xmit = &port->state->xmit;
139 unsigned int ch;
140 u32 val;
141
142 if (uart_tx_stopped(port)) {
143 meson_uart_stop_tx(port);
144 return;
145 }
146
147 while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
148 if (port->x_char) {
149 writel(port->x_char, port->membase + AML_UART_WFIFO);
150 port->icount.tx++;
151 port->x_char = 0;
152 continue;
153 }
154
155 if (uart_circ_empty(xmit))
156 break;
157
158 ch = xmit->buf[xmit->tail];
159 writel(ch, port->membase + AML_UART_WFIFO);
160 xmit->tail = (xmit->tail+1) & (SERIAL_XMIT_SIZE - 1);
161 port->icount.tx++;
162 }
163
164 if (!uart_circ_empty(xmit)) {
165 val = readl(port->membase + AML_UART_CONTROL);
166 val |= AML_UART_TX_INT_EN;
167 writel(val, port->membase + AML_UART_CONTROL);
168 }
169
170 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
171 uart_write_wakeup(port);
172}
173
174static void meson_receive_chars(struct uart_port *port)
175{
176 struct tty_port *tport = &port->state->port;
177 char flag;
178 u32 ostatus, status, ch, mode;
179
180 do {
181 flag = TTY_NORMAL;
182 port->icount.rx++;
183 ostatus = status = readl(port->membase + AML_UART_STATUS);
184
185 if (status & AML_UART_ERR) {
186 if (status & AML_UART_TX_FIFO_WERR)
187 port->icount.overrun++;
188 else if (status & AML_UART_FRAME_ERR)
189 port->icount.frame++;
190 else if (status & AML_UART_PARITY_ERR)
191 port->icount.frame++;
192
193 mode = readl(port->membase + AML_UART_CONTROL);
194 mode |= AML_UART_CLEAR_ERR;
195 writel(mode, port->membase + AML_UART_CONTROL);
196
197 /* It doesn't clear to 0 automatically */
198 mode &= ~AML_UART_CLEAR_ERR;
199 writel(mode, port->membase + AML_UART_CONTROL);
200
201 status &= port->read_status_mask;
202 if (status & AML_UART_FRAME_ERR)
203 flag = TTY_FRAME;
204 else if (status & AML_UART_PARITY_ERR)
205 flag = TTY_PARITY;
206 }
207
208 ch = readl(port->membase + AML_UART_RFIFO);
209 ch &= 0xff;
210
211 if ((ostatus & AML_UART_FRAME_ERR) && (ch == 0)) {
212 port->icount.brk++;
213 flag = TTY_BREAK;
214 if (uart_handle_break(port))
215 continue;
216 }
217
218 if (uart_handle_sysrq_char(port, ch))
219 continue;
220
221 if ((status & port->ignore_status_mask) == 0)
222 tty_insert_flip_char(tport, ch, flag);
223
224 if (status & AML_UART_TX_FIFO_WERR)
225 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
226
227 } while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY));
228
229 tty_flip_buffer_push(tport);
230}
231
232static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
233{
234 struct uart_port *port = (struct uart_port *)dev_id;
235
236 spin_lock(&port->lock);
237
238 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
239 meson_receive_chars(port);
240
241 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
242 if (readl(port->membase + AML_UART_CONTROL) & AML_UART_TX_INT_EN)
243 meson_uart_start_tx(port);
244 }
245
246 spin_unlock(&port->lock);
247
248 return IRQ_HANDLED;
249}
250
251static const char *meson_uart_type(struct uart_port *port)
252{
253 return (port->type == PORT_MESON) ? "meson_uart" : NULL;
254}
255
256static void meson_uart_reset(struct uart_port *port)
257{
258 u32 val;
259
260 val = readl(port->membase + AML_UART_CONTROL);
261 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
262 writel(val, port->membase + AML_UART_CONTROL);
263
264 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR);
265 writel(val, port->membase + AML_UART_CONTROL);
266}
267
268static int meson_uart_startup(struct uart_port *port)
269{
270 u32 val;
271 int ret = 0;
272
273 val = readl(port->membase + AML_UART_CONTROL);
274 val |= AML_UART_CLEAR_ERR;
275 writel(val, port->membase + AML_UART_CONTROL);
276 val &= ~AML_UART_CLEAR_ERR;
277 writel(val, port->membase + AML_UART_CONTROL);
278
279 val |= (AML_UART_RX_EN | AML_UART_TX_EN);
280 writel(val, port->membase + AML_UART_CONTROL);
281
282 val |= (AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
283 writel(val, port->membase + AML_UART_CONTROL);
284
285 val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2));
286 writel(val, port->membase + AML_UART_MISC);
287
288 ret = request_irq(port->irq, meson_uart_interrupt, 0,
289 port->name, port);
290
291 return ret;
292}
293
294static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
295{
296 u32 val;
297
298 while (!meson_uart_tx_empty(port))
299 cpu_relax();
300
301 if (port->uartclk == 24000000) {
302 val = ((port->uartclk / 3) / baud) - 1;
303 val |= AML_UART_BAUD_XTAL;
304 } else {
305 val = ((port->uartclk * 10 / (baud * 4) + 5) / 10) - 1;
306 }
307 val |= AML_UART_BAUD_USE;
308 writel(val, port->membase + AML_UART_REG5);
309}
310
311static void meson_uart_set_termios(struct uart_port *port,
312 struct ktermios *termios,
313 struct ktermios *old)
314{
315 unsigned int cflags, iflags, baud;
316 unsigned long flags;
317 u32 val;
318
319 spin_lock_irqsave(&port->lock, flags);
320
321 cflags = termios->c_cflag;
322 iflags = termios->c_iflag;
323
324 val = readl(port->membase + AML_UART_CONTROL);
325
326 val &= ~AML_UART_DATA_LEN_MASK;
327 switch (cflags & CSIZE) {
328 case CS8:
329 val |= AML_UART_DATA_LEN_8BIT;
330 break;
331 case CS7:
332 val |= AML_UART_DATA_LEN_7BIT;
333 break;
334 case CS6:
335 val |= AML_UART_DATA_LEN_6BIT;
336 break;
337 case CS5:
338 val |= AML_UART_DATA_LEN_5BIT;
339 break;
340 }
341
342 if (cflags & PARENB)
343 val |= AML_UART_PARITY_EN;
344 else
345 val &= ~AML_UART_PARITY_EN;
346
347 if (cflags & PARODD)
348 val |= AML_UART_PARITY_TYPE;
349 else
350 val &= ~AML_UART_PARITY_TYPE;
351
352 val &= ~AML_UART_STOP_BIT_LEN_MASK;
353 if (cflags & CSTOPB)
354 val |= AML_UART_STOP_BIT_2SB;
355 else
356 val |= AML_UART_STOP_BIT_1SB;
357
358 if (cflags & CRTSCTS)
359 val &= ~AML_UART_TWO_WIRE_EN;
360 else
361 val |= AML_UART_TWO_WIRE_EN;
362
363 writel(val, port->membase + AML_UART_CONTROL);
364
365 baud = uart_get_baud_rate(port, termios, old, 50, 4000000);
366 meson_uart_change_speed(port, baud);
367
368 port->read_status_mask = AML_UART_TX_FIFO_WERR;
369 if (iflags & INPCK)
370 port->read_status_mask |= AML_UART_PARITY_ERR |
371 AML_UART_FRAME_ERR;
372
373 port->ignore_status_mask = 0;
374 if (iflags & IGNPAR)
375 port->ignore_status_mask |= AML_UART_PARITY_ERR |
376 AML_UART_FRAME_ERR;
377
378 uart_update_timeout(port, termios->c_cflag, baud);
379 spin_unlock_irqrestore(&port->lock, flags);
380}
381
382static int meson_uart_verify_port(struct uart_port *port,
383 struct serial_struct *ser)
384{
385 int ret = 0;
386
387 if (port->type != PORT_MESON)
388 ret = -EINVAL;
389 if (port->irq != ser->irq)
390 ret = -EINVAL;
391 if (ser->baud_base < 9600)
392 ret = -EINVAL;
393 return ret;
394}
395
396static void meson_uart_release_port(struct uart_port *port)
397{
398 devm_iounmap(port->dev, port->membase);
399 port->membase = NULL;
400 devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
401}
402
403static int meson_uart_request_port(struct uart_port *port)
404{
405 if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
406 dev_name(port->dev))) {
407 dev_err(port->dev, "Memory region busy\n");
408 return -EBUSY;
409 }
410
411 port->membase = devm_ioremap(port->dev, port->mapbase,
412 port->mapsize);
413 if (!port->membase)
414 return -ENOMEM;
415
416 return 0;
417}
418
419static void meson_uart_config_port(struct uart_port *port, int flags)
420{
421 if (flags & UART_CONFIG_TYPE) {
422 port->type = PORT_MESON;
423 meson_uart_request_port(port);
424 }
425}
426
427#ifdef CONFIG_CONSOLE_POLL
428/*
429 * Console polling routines for writing and reading from the uart while
430 * in an interrupt or debug context (i.e. kgdb).
431 */
432
433static int meson_uart_poll_get_char(struct uart_port *port)
434{
435 u32 c;
436 unsigned long flags;
437
438 spin_lock_irqsave(&port->lock, flags);
439
440 if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
441 c = NO_POLL_CHAR;
442 else
443 c = readl(port->membase + AML_UART_RFIFO);
444
445 spin_unlock_irqrestore(&port->lock, flags);
446
447 return c;
448}
449
450static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
451{
452 unsigned long flags;
453 u32 reg;
454 int ret;
455
456 spin_lock_irqsave(&port->lock, flags);
457
458 /* Wait until FIFO is empty or timeout */
459 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
460 reg & AML_UART_TX_EMPTY,
461 AML_UART_POLL_USEC,
462 AML_UART_TIMEOUT_USEC);
463 if (ret == -ETIMEDOUT) {
464 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
465 goto out;
466 }
467
468 /* Write the character */
469 writel(c, port->membase + AML_UART_WFIFO);
470
471 /* Wait until FIFO is empty or timeout */
472 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
473 reg & AML_UART_TX_EMPTY,
474 AML_UART_POLL_USEC,
475 AML_UART_TIMEOUT_USEC);
476 if (ret == -ETIMEDOUT)
477 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
478
479out:
480 spin_unlock_irqrestore(&port->lock, flags);
481}
482
483#endif /* CONFIG_CONSOLE_POLL */
484
485static const struct uart_ops meson_uart_ops = {
486 .set_mctrl = meson_uart_set_mctrl,
487 .get_mctrl = meson_uart_get_mctrl,
488 .tx_empty = meson_uart_tx_empty,
489 .start_tx = meson_uart_start_tx,
490 .stop_tx = meson_uart_stop_tx,
491 .stop_rx = meson_uart_stop_rx,
492 .startup = meson_uart_startup,
493 .shutdown = meson_uart_shutdown,
494 .set_termios = meson_uart_set_termios,
495 .type = meson_uart_type,
496 .config_port = meson_uart_config_port,
497 .request_port = meson_uart_request_port,
498 .release_port = meson_uart_release_port,
499 .verify_port = meson_uart_verify_port,
500#ifdef CONFIG_CONSOLE_POLL
501 .poll_get_char = meson_uart_poll_get_char,
502 .poll_put_char = meson_uart_poll_put_char,
503#endif
504};
505
506#ifdef CONFIG_SERIAL_MESON_CONSOLE
507static void meson_uart_enable_tx_engine(struct uart_port *port)
508{
509 u32 val;
510
511 val = readl(port->membase + AML_UART_CONTROL);
512 val |= AML_UART_TX_EN;
513 writel(val, port->membase + AML_UART_CONTROL);
514}
515
516static void meson_console_putchar(struct uart_port *port, int ch)
517{
518 if (!port->membase)
519 return;
520
521 while (readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)
522 cpu_relax();
523 writel(ch, port->membase + AML_UART_WFIFO);
524}
525
526static void meson_serial_port_write(struct uart_port *port, const char *s,
527 u_int count)
528{
529 unsigned long flags;
530 int locked;
531 u32 val, tmp;
532
533 local_irq_save(flags);
534 if (port->sysrq) {
535 locked = 0;
536 } else if (oops_in_progress) {
537 locked = spin_trylock(&port->lock);
538 } else {
539 spin_lock(&port->lock);
540 locked = 1;
541 }
542
543 val = readl(port->membase + AML_UART_CONTROL);
544 tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
545 writel(tmp, port->membase + AML_UART_CONTROL);
546
547 uart_console_write(port, s, count, meson_console_putchar);
548 writel(val, port->membase + AML_UART_CONTROL);
549
550 if (locked)
551 spin_unlock(&port->lock);
552 local_irq_restore(flags);
553}
554
555static void meson_serial_console_write(struct console *co, const char *s,
556 u_int count)
557{
558 struct uart_port *port;
559
560 port = meson_ports[co->index];
561 if (!port)
562 return;
563
564 meson_serial_port_write(port, s, count);
565}
566
567static int meson_serial_console_setup(struct console *co, char *options)
568{
569 struct uart_port *port;
570 int baud = 115200;
571 int bits = 8;
572 int parity = 'n';
573 int flow = 'n';
574
575 if (co->index < 0 || co->index >= AML_UART_PORT_NUM)
576 return -EINVAL;
577
578 port = meson_ports[co->index];
579 if (!port || !port->membase)
580 return -ENODEV;
581
582 meson_uart_enable_tx_engine(port);
583
584 if (options)
585 uart_parse_options(options, &baud, &parity, &bits, &flow);
586
587 return uart_set_options(port, co, baud, parity, bits, flow);
588}
589
590static struct console meson_serial_console = {
591 .name = AML_UART_DEV_NAME,
592 .write = meson_serial_console_write,
593 .device = uart_console_device,
594 .setup = meson_serial_console_setup,
595 .flags = CON_PRINTBUFFER,
596 .index = -1,
597 .data = &meson_uart_driver,
598};
599
600static int __init meson_serial_console_init(void)
601{
602 register_console(&meson_serial_console);
603 return 0;
604}
605
606static void meson_serial_early_console_write(struct console *co,
607 const char *s,
608 u_int count)
609{
610 struct earlycon_device *dev = co->data;
611
612 meson_serial_port_write(&dev->port, s, count);
613}
614
615static int __init
616meson_serial_early_console_setup(struct earlycon_device *device, const char *opt)
617{
618 if (!device->port.membase)
619 return -ENODEV;
620
621 meson_uart_enable_tx_engine(&device->port);
622 device->con->write = meson_serial_early_console_write;
623 return 0;
624}
625/* Legacy bindings, should be removed when no more used */
626OF_EARLYCON_DECLARE(meson, "amlogic,meson-uart",
627 meson_serial_early_console_setup);
628/* Stable bindings */
629OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart",
630 meson_serial_early_console_setup);
631
632#define MESON_SERIAL_CONSOLE (&meson_serial_console)
633#else
634static int __init meson_serial_console_init(void) {
635 return 0;
636}
637#define MESON_SERIAL_CONSOLE NULL
638#endif
639
640static struct uart_driver meson_uart_driver = {
641 .owner = THIS_MODULE,
642 .driver_name = "meson_uart",
643 .dev_name = AML_UART_DEV_NAME,
644 .nr = AML_UART_PORT_NUM,
645 .cons = MESON_SERIAL_CONSOLE,
646};
647
648static inline struct clk *meson_uart_probe_clock(struct device *dev,
649 const char *id)
650{
651 struct clk *clk = NULL;
652 int ret;
653
654 clk = devm_clk_get(dev, id);
655 if (IS_ERR(clk))
656 return clk;
657
658 ret = clk_prepare_enable(clk);
659 if (ret) {
660 dev_err(dev, "couldn't enable clk\n");
661 return ERR_PTR(ret);
662 }
663
664 devm_add_action_or_reset(dev,
665 (void(*)(void *))clk_disable_unprepare,
666 clk);
667
668 return clk;
669}
670
671/*
672 * This function gets clocks in the legacy non-stable DT bindings.
673 * This code will be remove once all the platforms switch to the
674 * new DT bindings.
675 */
676static int meson_uart_probe_clocks_legacy(struct platform_device *pdev,
677 struct uart_port *port)
678{
679 struct clk *clk = NULL;
680
681 clk = meson_uart_probe_clock(&pdev->dev, NULL);
682 if (IS_ERR(clk))
683 return PTR_ERR(clk);
684
685 port->uartclk = clk_get_rate(clk);
686
687 return 0;
688}
689
690static int meson_uart_probe_clocks(struct platform_device *pdev,
691 struct uart_port *port)
692{
693 struct clk *clk_xtal = NULL;
694 struct clk *clk_pclk = NULL;
695 struct clk *clk_baud = NULL;
696
697 clk_pclk = meson_uart_probe_clock(&pdev->dev, "pclk");
698 if (IS_ERR(clk_pclk))
699 return PTR_ERR(clk_pclk);
700
701 clk_xtal = meson_uart_probe_clock(&pdev->dev, "xtal");
702 if (IS_ERR(clk_xtal))
703 return PTR_ERR(clk_xtal);
704
705 clk_baud = meson_uart_probe_clock(&pdev->dev, "baud");
706 if (IS_ERR(clk_baud))
707 return PTR_ERR(clk_baud);
708
709 port->uartclk = clk_get_rate(clk_baud);
710
711 return 0;
712}
713
714static int meson_uart_probe(struct platform_device *pdev)
715{
716 struct resource *res_mem, *res_irq;
717 struct uart_port *port;
718 u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
719 int ret = 0;
720
721 if (pdev->dev.of_node)
722 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
723
724 if (pdev->id < 0) {
725 int id;
726
727 for (id = AML_UART_PORT_OFFSET; id < AML_UART_PORT_NUM; id++) {
728 if (!meson_ports[id]) {
729 pdev->id = id;
730 break;
731 }
732 }
733 }
734
735 if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM)
736 return -EINVAL;
737
738 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
739 if (!res_mem)
740 return -ENODEV;
741
742 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
743 if (!res_irq)
744 return -ENODEV;
745
746 of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
747
748 if (meson_ports[pdev->id]) {
749 dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
750 return -EBUSY;
751 }
752
753 port = devm_kzalloc(&pdev->dev, sizeof(struct uart_port), GFP_KERNEL);
754 if (!port)
755 return -ENOMEM;
756
757 /* Use legacy way until all platforms switch to new bindings */
758 if (of_device_is_compatible(pdev->dev.of_node, "amlogic,meson-uart"))
759 ret = meson_uart_probe_clocks_legacy(pdev, port);
760 else
761 ret = meson_uart_probe_clocks(pdev, port);
762
763 if (ret)
764 return ret;
765
766 port->iotype = UPIO_MEM;
767 port->mapbase = res_mem->start;
768 port->mapsize = resource_size(res_mem);
769 port->irq = res_irq->start;
770 port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
771 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
772 port->dev = &pdev->dev;
773 port->line = pdev->id;
774 port->type = PORT_MESON;
775 port->x_char = 0;
776 port->ops = &meson_uart_ops;
777 port->fifosize = fifosize;
778
779 meson_ports[pdev->id] = port;
780 platform_set_drvdata(pdev, port);
781
782 /* reset port before registering (and possibly registering console) */
783 if (meson_uart_request_port(port) >= 0) {
784 meson_uart_reset(port);
785 meson_uart_release_port(port);
786 }
787
788 ret = uart_add_one_port(&meson_uart_driver, port);
789 if (ret)
790 meson_ports[pdev->id] = NULL;
791
792 return ret;
793}
794
795static int meson_uart_remove(struct platform_device *pdev)
796{
797 struct uart_port *port;
798
799 port = platform_get_drvdata(pdev);
800 uart_remove_one_port(&meson_uart_driver, port);
801 meson_ports[pdev->id] = NULL;
802
803 return 0;
804}
805
806static const struct of_device_id meson_uart_dt_match[] = {
807 /* Legacy bindings, should be removed when no more used */
808 { .compatible = "amlogic,meson-uart" },
809 /* Stable bindings */
810 { .compatible = "amlogic,meson6-uart" },
811 { .compatible = "amlogic,meson8-uart" },
812 { .compatible = "amlogic,meson8b-uart" },
813 { .compatible = "amlogic,meson-gx-uart" },
814 { /* sentinel */ },
815};
816MODULE_DEVICE_TABLE(of, meson_uart_dt_match);
817
818static struct platform_driver meson_uart_platform_driver = {
819 .probe = meson_uart_probe,
820 .remove = meson_uart_remove,
821 .driver = {
822 .name = "meson_uart",
823 .of_match_table = meson_uart_dt_match,
824 },
825};
826
827static int __init meson_uart_init(void)
828{
829 int ret;
830
831 ret = meson_serial_console_init();
832 if (ret)
833 return ret;
834
835 ret = uart_register_driver(&meson_uart_driver);
836 if (ret)
837 return ret;
838
839 ret = platform_driver_register(&meson_uart_platform_driver);
840 if (ret)
841 uart_unregister_driver(&meson_uart_driver);
842
843 return ret;
844}
845
846static void __exit meson_uart_exit(void)
847{
848 platform_driver_unregister(&meson_uart_platform_driver);
849 uart_unregister_driver(&meson_uart_driver);
850}
851
852module_init(meson_uart_init);
853module_exit(meson_uart_exit);
854
855MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
856MODULE_DESCRIPTION("Amlogic Meson serial port driver");
857MODULE_LICENSE("GPL v2");