1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * ***************************************************************************
4 * Marvell Armada-3700 Serial Driver
5 * Author: Wilson Ding <dingwei@marvell.com>
6 * Copyright (C) 2015 Marvell International Ltd.
7 * ***************************************************************************
8 */
9
10 #include <linux/clk.h>
11 #include <linux/console.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/iopoll.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/serial.h>
24 #include <linux/serial_core.h>
25 #include <linux/slab.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28
29 /* Register Map */
30 #define UART_STD_RBR 0x00
31 #define UART_EXT_RBR 0x18
32
33 #define UART_STD_TSH 0x04
34 #define UART_EXT_TSH 0x1C
35
36 #define UART_STD_CTRL1 0x08
37 #define UART_EXT_CTRL1 0x04
38 #define CTRL_SOFT_RST BIT(31)
39 #define CTRL_TXFIFO_RST BIT(15)
40 #define CTRL_RXFIFO_RST BIT(14)
41 #define CTRL_SND_BRK_SEQ BIT(11)
42 #define CTRL_BRK_DET_INT BIT(3)
43 #define CTRL_FRM_ERR_INT BIT(2)
44 #define CTRL_PAR_ERR_INT BIT(1)
45 #define CTRL_OVR_ERR_INT BIT(0)
46 #define CTRL_BRK_INT (CTRL_BRK_DET_INT | CTRL_FRM_ERR_INT | \
47 CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT)
48
49 #define UART_STD_CTRL2 UART_STD_CTRL1
50 #define UART_EXT_CTRL2 0x20
51 #define CTRL_STD_TX_RDY_INT BIT(5)
52 #define CTRL_EXT_TX_RDY_INT BIT(6)
53 #define CTRL_STD_RX_RDY_INT BIT(4)
54 #define CTRL_EXT_RX_RDY_INT BIT(5)
55
56 #define UART_STAT 0x0C
57 #define STAT_TX_FIFO_EMP BIT(13)
58 #define STAT_TX_FIFO_FUL BIT(11)
59 #define STAT_TX_EMP BIT(6)
60 #define STAT_STD_TX_RDY BIT(5)
61 #define STAT_EXT_TX_RDY BIT(15)
62 #define STAT_STD_RX_RDY BIT(4)
63 #define STAT_EXT_RX_RDY BIT(14)
64 #define STAT_BRK_DET BIT(3)
65 #define STAT_FRM_ERR BIT(2)
66 #define STAT_PAR_ERR BIT(1)
67 #define STAT_OVR_ERR BIT(0)
68 #define STAT_BRK_ERR (STAT_BRK_DET | STAT_FRM_ERR \
69 | STAT_PAR_ERR | STAT_OVR_ERR)
70
71 #define UART_BRDV 0x10
72 #define BRDV_BAUD_MASK 0x3FF
73
74 #define UART_OSAMP 0x14
75 #define OSAMP_DEFAULT_DIVISOR 16
76 #define OSAMP_DIVISORS_MASK 0x3F3F3F3F
77
78 #define MVEBU_NR_UARTS 2
79
80 #define MVEBU_UART_TYPE "mvebu-uart"
81 #define DRIVER_NAME "mvebu_serial"
82
83 enum {
84 /* Either there is only one summed IRQ... */
85 UART_IRQ_SUM = 0,
86 /* ...or there are two separate IRQ for RX and TX */
87 UART_RX_IRQ = 0,
88 UART_TX_IRQ,
89 UART_IRQ_COUNT
90 };
91
92 /* Diverging register offsets */
93 struct uart_regs_layout {
94 unsigned int rbr;
95 unsigned int tsh;
96 unsigned int ctrl;
97 unsigned int intr;
98 };
99
100 /* Diverging flags */
101 struct uart_flags {
102 unsigned int ctrl_tx_rdy_int;
103 unsigned int ctrl_rx_rdy_int;
104 unsigned int stat_tx_rdy;
105 unsigned int stat_rx_rdy;
106 };
107
108 /* Driver data, a structure for each UART port */
109 struct mvebu_uart_driver_data {
110 bool is_ext;
111 struct uart_regs_layout regs;
112 struct uart_flags flags;
113 };
114
115 /* Saved registers during suspend */
116 struct mvebu_uart_pm_regs {
117 unsigned int rbr;
118 unsigned int tsh;
119 unsigned int ctrl;
120 unsigned int intr;
121 unsigned int stat;
122 unsigned int brdv;
123 unsigned int osamp;
124 };
125
126 /* MVEBU UART driver structure */
127 struct mvebu_uart {
128 struct uart_port *port;
129 struct clk *clk;
130 int irq[UART_IRQ_COUNT];
131 unsigned char __iomem *nb;
132 struct mvebu_uart_driver_data *data;
133 #if defined(CONFIG_PM)
134 struct mvebu_uart_pm_regs pm_regs;
135 #endif /* CONFIG_PM */
136 };
137
to_mvuart(struct uart_port * port)138 static struct mvebu_uart *to_mvuart(struct uart_port *port)
139 {
140 return (struct mvebu_uart *)port->private_data;
141 }
142
143 #define IS_EXTENDED(port) (to_mvuart(port)->data->is_ext)
144
145 #define UART_RBR(port) (to_mvuart(port)->data->regs.rbr)
146 #define UART_TSH(port) (to_mvuart(port)->data->regs.tsh)
147 #define UART_CTRL(port) (to_mvuart(port)->data->regs.ctrl)
148 #define UART_INTR(port) (to_mvuart(port)->data->regs.intr)
149
150 #define CTRL_TX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_tx_rdy_int)
151 #define CTRL_RX_RDY_INT(port) (to_mvuart(port)->data->flags.ctrl_rx_rdy_int)
152 #define STAT_TX_RDY(port) (to_mvuart(port)->data->flags.stat_tx_rdy)
153 #define STAT_RX_RDY(port) (to_mvuart(port)->data->flags.stat_rx_rdy)
154
155 static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS];
156
157 /* Core UART Driver Operations */
mvebu_uart_tx_empty(struct uart_port * port)158 static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
159 {
160 unsigned long flags;
161 unsigned int st;
162
163 spin_lock_irqsave(&port->lock, flags);
164 st = readl(port->membase + UART_STAT);
165 spin_unlock_irqrestore(&port->lock, flags);
166
167 return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0;
168 }
169
mvebu_uart_get_mctrl(struct uart_port * port)170 static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
171 {
172 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
173 }
174
mvebu_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)175 static void mvebu_uart_set_mctrl(struct uart_port *port,
176 unsigned int mctrl)
177 {
178 /*
179 * Even if we do not support configuring the modem control lines, this
180 * function must be proided to the serial core
181 */
182 }
183
mvebu_uart_stop_tx(struct uart_port * port)184 static void mvebu_uart_stop_tx(struct uart_port *port)
185 {
186 unsigned int ctl = readl(port->membase + UART_INTR(port));
187
188 ctl &= ~CTRL_TX_RDY_INT(port);
189 writel(ctl, port->membase + UART_INTR(port));
190 }
191
mvebu_uart_start_tx(struct uart_port * port)192 static void mvebu_uart_start_tx(struct uart_port *port)
193 {
194 unsigned int ctl;
195 struct circ_buf *xmit = &port->state->xmit;
196
197 if (IS_EXTENDED(port) && !uart_circ_empty(xmit)) {
198 writel(xmit->buf[xmit->tail], port->membase + UART_TSH(port));
199 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
200 port->icount.tx++;
201 }
202
203 ctl = readl(port->membase + UART_INTR(port));
204 ctl |= CTRL_TX_RDY_INT(port);
205 writel(ctl, port->membase + UART_INTR(port));
206 }
207
mvebu_uart_stop_rx(struct uart_port * port)208 static void mvebu_uart_stop_rx(struct uart_port *port)
209 {
210 unsigned int ctl;
211
212 ctl = readl(port->membase + UART_CTRL(port));
213 ctl &= ~CTRL_BRK_INT;
214 writel(ctl, port->membase + UART_CTRL(port));
215
216 ctl = readl(port->membase + UART_INTR(port));
217 ctl &= ~CTRL_RX_RDY_INT(port);
218 writel(ctl, port->membase + UART_INTR(port));
219 }
220
mvebu_uart_break_ctl(struct uart_port * port,int brk)221 static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
222 {
223 unsigned int ctl;
224 unsigned long flags;
225
226 spin_lock_irqsave(&port->lock, flags);
227 ctl = readl(port->membase + UART_CTRL(port));
228 if (brk == -1)
229 ctl |= CTRL_SND_BRK_SEQ;
230 else
231 ctl &= ~CTRL_SND_BRK_SEQ;
232 writel(ctl, port->membase + UART_CTRL(port));
233 spin_unlock_irqrestore(&port->lock, flags);
234 }
235
mvebu_uart_rx_chars(struct uart_port * port,unsigned int status)236 static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
237 {
238 struct tty_port *tport = &port->state->port;
239 unsigned char ch = 0;
240 char flag = 0;
241
242 do {
243 if (status & STAT_RX_RDY(port)) {
244 ch = readl(port->membase + UART_RBR(port));
245 ch &= 0xff;
246 flag = TTY_NORMAL;
247 port->icount.rx++;
248
249 if (status & STAT_PAR_ERR)
250 port->icount.parity++;
251 }
252
253 if (status & STAT_BRK_DET) {
254 port->icount.brk++;
255 status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
256 if (uart_handle_break(port))
257 goto ignore_char;
258 }
259
260 if (status & STAT_OVR_ERR)
261 port->icount.overrun++;
262
263 if (status & STAT_FRM_ERR)
264 port->icount.frame++;
265
266 if (uart_handle_sysrq_char(port, ch))
267 goto ignore_char;
268
269 if (status & port->ignore_status_mask & STAT_PAR_ERR)
270 status &= ~STAT_RX_RDY(port);
271
272 status &= port->read_status_mask;
273
274 if (status & STAT_PAR_ERR)
275 flag = TTY_PARITY;
276
277 status &= ~port->ignore_status_mask;
278
279 if (status & STAT_RX_RDY(port))
280 tty_insert_flip_char(tport, ch, flag);
281
282 if (status & STAT_BRK_DET)
283 tty_insert_flip_char(tport, 0, TTY_BREAK);
284
285 if (status & STAT_FRM_ERR)
286 tty_insert_flip_char(tport, 0, TTY_FRAME);
287
288 if (status & STAT_OVR_ERR)
289 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
290
291 ignore_char:
292 status = readl(port->membase + UART_STAT);
293 } while (status & (STAT_RX_RDY(port) | STAT_BRK_DET));
294
295 tty_flip_buffer_push(tport);
296 }
297
mvebu_uart_tx_chars(struct uart_port * port,unsigned int status)298 static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status)
299 {
300 struct circ_buf *xmit = &port->state->xmit;
301 unsigned int count;
302 unsigned int st;
303
304 if (port->x_char) {
305 writel(port->x_char, port->membase + UART_TSH(port));
306 port->icount.tx++;
307 port->x_char = 0;
308 return;
309 }
310
311 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
312 mvebu_uart_stop_tx(port);
313 return;
314 }
315
316 for (count = 0; count < port->fifosize; count++) {
317 writel(xmit->buf[xmit->tail], port->membase + UART_TSH(port));
318 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
319 port->icount.tx++;
320
321 if (uart_circ_empty(xmit))
322 break;
323
324 st = readl(port->membase + UART_STAT);
325 if (st & STAT_TX_FIFO_FUL)
326 break;
327 }
328
329 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
330 uart_write_wakeup(port);
331
332 if (uart_circ_empty(xmit))
333 mvebu_uart_stop_tx(port);
334 }
335
mvebu_uart_isr(int irq,void * dev_id)336 static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
337 {
338 struct uart_port *port = (struct uart_port *)dev_id;
339 unsigned int st = readl(port->membase + UART_STAT);
340
341 if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
342 STAT_BRK_DET))
343 mvebu_uart_rx_chars(port, st);
344
345 if (st & STAT_TX_RDY(port))
346 mvebu_uart_tx_chars(port, st);
347
348 return IRQ_HANDLED;
349 }
350
mvebu_uart_rx_isr(int irq,void * dev_id)351 static irqreturn_t mvebu_uart_rx_isr(int irq, void *dev_id)
352 {
353 struct uart_port *port = (struct uart_port *)dev_id;
354 unsigned int st = readl(port->membase + UART_STAT);
355
356 if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
357 STAT_BRK_DET))
358 mvebu_uart_rx_chars(port, st);
359
360 return IRQ_HANDLED;
361 }
362
mvebu_uart_tx_isr(int irq,void * dev_id)363 static irqreturn_t mvebu_uart_tx_isr(int irq, void *dev_id)
364 {
365 struct uart_port *port = (struct uart_port *)dev_id;
366 unsigned int st = readl(port->membase + UART_STAT);
367
368 if (st & STAT_TX_RDY(port))
369 mvebu_uart_tx_chars(port, st);
370
371 return IRQ_HANDLED;
372 }
373
mvebu_uart_startup(struct uart_port * port)374 static int mvebu_uart_startup(struct uart_port *port)
375 {
376 struct mvebu_uart *mvuart = to_mvuart(port);
377 unsigned int ctl;
378 int ret;
379
380 writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST,
381 port->membase + UART_CTRL(port));
382 udelay(1);
383
384 /* Clear the error bits of state register before IRQ request */
385 ret = readl(port->membase + UART_STAT);
386 ret |= STAT_BRK_ERR;
387 writel(ret, port->membase + UART_STAT);
388
389 writel(CTRL_BRK_INT, port->membase + UART_CTRL(port));
390
391 ctl = readl(port->membase + UART_INTR(port));
392 ctl |= CTRL_RX_RDY_INT(port);
393 writel(ctl, port->membase + UART_INTR(port));
394
395 if (!mvuart->irq[UART_TX_IRQ]) {
396 /* Old bindings with just one interrupt (UART0 only) */
397 ret = devm_request_irq(port->dev, mvuart->irq[UART_IRQ_SUM],
398 mvebu_uart_isr, port->irqflags,
399 dev_name(port->dev), port);
400 if (ret) {
401 dev_err(port->dev, "unable to request IRQ %d\n",
402 mvuart->irq[UART_IRQ_SUM]);
403 return ret;
404 }
405 } else {
406 /* New bindings with an IRQ for RX and TX (both UART) */
407 ret = devm_request_irq(port->dev, mvuart->irq[UART_RX_IRQ],
408 mvebu_uart_rx_isr, port->irqflags,
409 dev_name(port->dev), port);
410 if (ret) {
411 dev_err(port->dev, "unable to request IRQ %d\n",
412 mvuart->irq[UART_RX_IRQ]);
413 return ret;
414 }
415
416 ret = devm_request_irq(port->dev, mvuart->irq[UART_TX_IRQ],
417 mvebu_uart_tx_isr, port->irqflags,
418 dev_name(port->dev),
419 port);
420 if (ret) {
421 dev_err(port->dev, "unable to request IRQ %d\n",
422 mvuart->irq[UART_TX_IRQ]);
423 devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ],
424 port);
425 return ret;
426 }
427 }
428
429 return 0;
430 }
431
mvebu_uart_shutdown(struct uart_port * port)432 static void mvebu_uart_shutdown(struct uart_port *port)
433 {
434 struct mvebu_uart *mvuart = to_mvuart(port);
435
436 writel(0, port->membase + UART_INTR(port));
437
438 if (!mvuart->irq[UART_TX_IRQ]) {
439 devm_free_irq(port->dev, mvuart->irq[UART_IRQ_SUM], port);
440 } else {
441 devm_free_irq(port->dev, mvuart->irq[UART_RX_IRQ], port);
442 devm_free_irq(port->dev, mvuart->irq[UART_TX_IRQ], port);
443 }
444 }
445
mvebu_uart_baud_rate_set(struct uart_port * port,unsigned int baud)446 static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
447 {
448 struct mvebu_uart *mvuart = to_mvuart(port);
449 unsigned int d_divisor, m_divisor;
450 u32 brdv, osamp;
451
452 if (IS_ERR(mvuart->clk))
453 return -PTR_ERR(mvuart->clk);
454
455 /*
456 * The baudrate is derived from the UART clock thanks to two divisors:
457 * > D ("baud generator"): can divide the clock from 2 to 2^10 - 1.
458 * > M ("fractional divisor"): allows a better accuracy for
459 * baudrates higher than 230400.
460 *
461 * As the derivation of M is rather complicated, the code sticks to its
462 * default value (x16) when all the prescalers are zeroed, and only
463 * makes use of D to configure the desired baudrate.
464 */
465 m_divisor = OSAMP_DEFAULT_DIVISOR;
466 d_divisor = DIV_ROUND_UP(port->uartclk, baud * m_divisor);
467
468 brdv = readl(port->membase + UART_BRDV);
469 brdv &= ~BRDV_BAUD_MASK;
470 brdv |= d_divisor;
471 writel(brdv, port->membase + UART_BRDV);
472
473 osamp = readl(port->membase + UART_OSAMP);
474 osamp &= ~OSAMP_DIVISORS_MASK;
475 writel(osamp, port->membase + UART_OSAMP);
476
477 return 0;
478 }
479
mvebu_uart_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)480 static void mvebu_uart_set_termios(struct uart_port *port,
481 struct ktermios *termios,
482 struct ktermios *old)
483 {
484 unsigned long flags;
485 unsigned int baud;
486
487 spin_lock_irqsave(&port->lock, flags);
488
489 port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
490 STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
491
492 if (termios->c_iflag & INPCK)
493 port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR;
494
495 port->ignore_status_mask = 0;
496 if (termios->c_iflag & IGNPAR)
497 port->ignore_status_mask |=
498 STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR;
499
500 if ((termios->c_cflag & CREAD) == 0)
501 port->ignore_status_mask |= STAT_RX_RDY(port) | STAT_BRK_ERR;
502
503 /*
504 * Maximum achievable frequency with simple baudrate divisor is 230400.
505 * Since the error per bit frame would be of more than 15%, achieving
506 * higher frequencies would require to implement the fractional divisor
507 * feature.
508 */
509 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
510 if (mvebu_uart_baud_rate_set(port, baud)) {
511 /* No clock available, baudrate cannot be changed */
512 if (old)
513 baud = uart_get_baud_rate(port, old, NULL, 0, 230400);
514 } else {
515 tty_termios_encode_baud_rate(termios, baud, baud);
516 uart_update_timeout(port, termios->c_cflag, baud);
517 }
518
519 /* Only the following flag changes are supported */
520 if (old) {
521 termios->c_iflag &= INPCK | IGNPAR;
522 termios->c_iflag |= old->c_iflag & ~(INPCK | IGNPAR);
523 termios->c_cflag &= CREAD | CBAUD;
524 termios->c_cflag |= old->c_cflag & ~(CREAD | CBAUD);
525 termios->c_cflag |= CS8;
526 }
527
528 spin_unlock_irqrestore(&port->lock, flags);
529 }
530
mvebu_uart_type(struct uart_port * port)531 static const char *mvebu_uart_type(struct uart_port *port)
532 {
533 return MVEBU_UART_TYPE;
534 }
535
mvebu_uart_release_port(struct uart_port * port)536 static void mvebu_uart_release_port(struct uart_port *port)
537 {
538 /* Nothing to do here */
539 }
540
mvebu_uart_request_port(struct uart_port * port)541 static int mvebu_uart_request_port(struct uart_port *port)
542 {
543 return 0;
544 }
545
546 #ifdef CONFIG_CONSOLE_POLL
mvebu_uart_get_poll_char(struct uart_port * port)547 static int mvebu_uart_get_poll_char(struct uart_port *port)
548 {
549 unsigned int st = readl(port->membase + UART_STAT);
550
551 if (!(st & STAT_RX_RDY(port)))
552 return NO_POLL_CHAR;
553
554 return readl(port->membase + UART_RBR(port));
555 }
556
mvebu_uart_put_poll_char(struct uart_port * port,unsigned char c)557 static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c)
558 {
559 unsigned int st;
560
561 for (;;) {
562 st = readl(port->membase + UART_STAT);
563
564 if (!(st & STAT_TX_FIFO_FUL))
565 break;
566
567 udelay(1);
568 }
569
570 writel(c, port->membase + UART_TSH(port));
571 }
572 #endif
573
574 static const struct uart_ops mvebu_uart_ops = {
575 .tx_empty = mvebu_uart_tx_empty,
576 .set_mctrl = mvebu_uart_set_mctrl,
577 .get_mctrl = mvebu_uart_get_mctrl,
578 .stop_tx = mvebu_uart_stop_tx,
579 .start_tx = mvebu_uart_start_tx,
580 .stop_rx = mvebu_uart_stop_rx,
581 .break_ctl = mvebu_uart_break_ctl,
582 .startup = mvebu_uart_startup,
583 .shutdown = mvebu_uart_shutdown,
584 .set_termios = mvebu_uart_set_termios,
585 .type = mvebu_uart_type,
586 .release_port = mvebu_uart_release_port,
587 .request_port = mvebu_uart_request_port,
588 #ifdef CONFIG_CONSOLE_POLL
589 .poll_get_char = mvebu_uart_get_poll_char,
590 .poll_put_char = mvebu_uart_put_poll_char,
591 #endif
592 };
593
594 /* Console Driver Operations */
595
596 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
597 /* Early Console */
mvebu_uart_putc(struct uart_port * port,int c)598 static void mvebu_uart_putc(struct uart_port *port, int c)
599 {
600 unsigned int st;
601
602 for (;;) {
603 st = readl(port->membase + UART_STAT);
604 if (!(st & STAT_TX_FIFO_FUL))
605 break;
606 }
607
608 /* At early stage, DT is not parsed yet, only use UART0 */
609 writel(c, port->membase + UART_STD_TSH);
610
611 for (;;) {
612 st = readl(port->membase + UART_STAT);
613 if (st & STAT_TX_FIFO_EMP)
614 break;
615 }
616 }
617
mvebu_uart_putc_early_write(struct console * con,const char * s,unsigned n)618 static void mvebu_uart_putc_early_write(struct console *con,
619 const char *s,
620 unsigned n)
621 {
622 struct earlycon_device *dev = con->data;
623
624 uart_console_write(&dev->port, s, n, mvebu_uart_putc);
625 }
626
627 static int __init
mvebu_uart_early_console_setup(struct earlycon_device * device,const char * opt)628 mvebu_uart_early_console_setup(struct earlycon_device *device,
629 const char *opt)
630 {
631 if (!device->port.membase)
632 return -ENODEV;
633
634 device->con->write = mvebu_uart_putc_early_write;
635
636 return 0;
637 }
638
639 EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup);
640 OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart",
641 mvebu_uart_early_console_setup);
642
wait_for_xmitr(struct uart_port * port)643 static void wait_for_xmitr(struct uart_port *port)
644 {
645 u32 val;
646
647 readl_poll_timeout_atomic(port->membase + UART_STAT, val,
648 (val & STAT_TX_RDY(port)), 1, 10000);
649 }
650
wait_for_xmite(struct uart_port * port)651 static void wait_for_xmite(struct uart_port *port)
652 {
653 u32 val;
654
655 readl_poll_timeout_atomic(port->membase + UART_STAT, val,
656 (val & STAT_TX_EMP), 1, 10000);
657 }
658
mvebu_uart_console_putchar(struct uart_port * port,int ch)659 static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
660 {
661 wait_for_xmitr(port);
662 writel(ch, port->membase + UART_TSH(port));
663 }
664
mvebu_uart_console_write(struct console * co,const char * s,unsigned int count)665 static void mvebu_uart_console_write(struct console *co, const char *s,
666 unsigned int count)
667 {
668 struct uart_port *port = &mvebu_uart_ports[co->index];
669 unsigned long flags;
670 unsigned int ier, intr, ctl;
671 int locked = 1;
672
673 if (oops_in_progress)
674 locked = spin_trylock_irqsave(&port->lock, flags);
675 else
676 spin_lock_irqsave(&port->lock, flags);
677
678 ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
679 intr = readl(port->membase + UART_INTR(port)) &
680 (CTRL_RX_RDY_INT(port) | CTRL_TX_RDY_INT(port));
681 writel(0, port->membase + UART_CTRL(port));
682 writel(0, port->membase + UART_INTR(port));
683
684 uart_console_write(port, s, count, mvebu_uart_console_putchar);
685
686 wait_for_xmite(port);
687
688 if (ier)
689 writel(ier, port->membase + UART_CTRL(port));
690
691 if (intr) {
692 ctl = intr | readl(port->membase + UART_INTR(port));
693 writel(ctl, port->membase + UART_INTR(port));
694 }
695
696 if (locked)
697 spin_unlock_irqrestore(&port->lock, flags);
698 }
699
mvebu_uart_console_setup(struct console * co,char * options)700 static int mvebu_uart_console_setup(struct console *co, char *options)
701 {
702 struct uart_port *port;
703 int baud = 9600;
704 int bits = 8;
705 int parity = 'n';
706 int flow = 'n';
707
708 if (co->index < 0 || co->index >= MVEBU_NR_UARTS)
709 return -EINVAL;
710
711 port = &mvebu_uart_ports[co->index];
712
713 if (!port->mapbase || !port->membase) {
714 pr_debug("console on ttyMV%i not present\n", co->index);
715 return -ENODEV;
716 }
717
718 if (options)
719 uart_parse_options(options, &baud, &parity, &bits, &flow);
720
721 return uart_set_options(port, co, baud, parity, bits, flow);
722 }
723
724 static struct uart_driver mvebu_uart_driver;
725
726 static struct console mvebu_uart_console = {
727 .name = "ttyMV",
728 .write = mvebu_uart_console_write,
729 .device = uart_console_device,
730 .setup = mvebu_uart_console_setup,
731 .flags = CON_PRINTBUFFER,
732 .index = -1,
733 .data = &mvebu_uart_driver,
734 };
735
mvebu_uart_console_init(void)736 static int __init mvebu_uart_console_init(void)
737 {
738 register_console(&mvebu_uart_console);
739 return 0;
740 }
741
742 console_initcall(mvebu_uart_console_init);
743
744
745 #endif /* CONFIG_SERIAL_MVEBU_CONSOLE */
746
747 static struct uart_driver mvebu_uart_driver = {
748 .owner = THIS_MODULE,
749 .driver_name = DRIVER_NAME,
750 .dev_name = "ttyMV",
751 .nr = MVEBU_NR_UARTS,
752 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
753 .cons = &mvebu_uart_console,
754 #endif
755 };
756
757 #if defined(CONFIG_PM)
mvebu_uart_suspend(struct device * dev)758 static int mvebu_uart_suspend(struct device *dev)
759 {
760 struct mvebu_uart *mvuart = dev_get_drvdata(dev);
761 struct uart_port *port = mvuart->port;
762
763 uart_suspend_port(&mvebu_uart_driver, port);
764
765 mvuart->pm_regs.rbr = readl(port->membase + UART_RBR(port));
766 mvuart->pm_regs.tsh = readl(port->membase + UART_TSH(port));
767 mvuart->pm_regs.ctrl = readl(port->membase + UART_CTRL(port));
768 mvuart->pm_regs.intr = readl(port->membase + UART_INTR(port));
769 mvuart->pm_regs.stat = readl(port->membase + UART_STAT);
770 mvuart->pm_regs.brdv = readl(port->membase + UART_BRDV);
771 mvuart->pm_regs.osamp = readl(port->membase + UART_OSAMP);
772
773 device_set_wakeup_enable(dev, true);
774
775 return 0;
776 }
777
mvebu_uart_resume(struct device * dev)778 static int mvebu_uart_resume(struct device *dev)
779 {
780 struct mvebu_uart *mvuart = dev_get_drvdata(dev);
781 struct uart_port *port = mvuart->port;
782
783 writel(mvuart->pm_regs.rbr, port->membase + UART_RBR(port));
784 writel(mvuart->pm_regs.tsh, port->membase + UART_TSH(port));
785 writel(mvuart->pm_regs.ctrl, port->membase + UART_CTRL(port));
786 writel(mvuart->pm_regs.intr, port->membase + UART_INTR(port));
787 writel(mvuart->pm_regs.stat, port->membase + UART_STAT);
788 writel(mvuart->pm_regs.brdv, port->membase + UART_BRDV);
789 writel(mvuart->pm_regs.osamp, port->membase + UART_OSAMP);
790
791 uart_resume_port(&mvebu_uart_driver, port);
792
793 return 0;
794 }
795
796 static const struct dev_pm_ops mvebu_uart_pm_ops = {
797 .suspend = mvebu_uart_suspend,
798 .resume = mvebu_uart_resume,
799 };
800 #endif /* CONFIG_PM */
801
802 static const struct of_device_id mvebu_uart_of_match[];
803
804 /* Counter to keep track of each UART port id when not using CONFIG_OF */
805 static int uart_num_counter;
806
mvebu_uart_probe(struct platform_device * pdev)807 static int mvebu_uart_probe(struct platform_device *pdev)
808 {
809 struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
810 const struct of_device_id *match = of_match_device(mvebu_uart_of_match,
811 &pdev->dev);
812 struct uart_port *port;
813 struct mvebu_uart *mvuart;
814 int id, irq;
815
816 if (!reg) {
817 dev_err(&pdev->dev, "no registers defined\n");
818 return -EINVAL;
819 }
820
821 if (!match)
822 return -ENODEV;
823
824 /* Assume that all UART ports have a DT alias or none has */
825 id = of_alias_get_id(pdev->dev.of_node, "serial");
826 if (!pdev->dev.of_node || id < 0)
827 pdev->id = uart_num_counter++;
828 else
829 pdev->id = id;
830
831 if (pdev->id >= MVEBU_NR_UARTS) {
832 dev_err(&pdev->dev, "cannot have more than %d UART ports\n",
833 MVEBU_NR_UARTS);
834 return -EINVAL;
835 }
836
837 port = &mvebu_uart_ports[pdev->id];
838
839 spin_lock_init(&port->lock);
840
841 port->dev = &pdev->dev;
842 port->type = PORT_MVEBU;
843 port->ops = &mvebu_uart_ops;
844 port->regshift = 0;
845
846 port->fifosize = 32;
847 port->iotype = UPIO_MEM32;
848 port->flags = UPF_FIXED_PORT;
849 port->line = pdev->id;
850
851 /*
852 * IRQ number is not stored in this structure because we may have two of
853 * them per port (RX and TX). Instead, use the driver UART structure
854 * array so called ->irq[].
855 */
856 port->irq = 0;
857 port->irqflags = 0;
858 port->mapbase = reg->start;
859
860 port->membase = devm_ioremap_resource(&pdev->dev, reg);
861 if (IS_ERR(port->membase))
862 return PTR_ERR(port->membase);
863
864 mvuart = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart),
865 GFP_KERNEL);
866 if (!mvuart)
867 return -ENOMEM;
868
869 /* Get controller data depending on the compatible string */
870 mvuart->data = (struct mvebu_uart_driver_data *)match->data;
871 mvuart->port = port;
872
873 port->private_data = mvuart;
874 platform_set_drvdata(pdev, mvuart);
875
876 /* Get fixed clock frequency */
877 mvuart->clk = devm_clk_get(&pdev->dev, NULL);
878 if (IS_ERR(mvuart->clk)) {
879 if (PTR_ERR(mvuart->clk) == -EPROBE_DEFER)
880 return PTR_ERR(mvuart->clk);
881
882 if (IS_EXTENDED(port)) {
883 dev_err(&pdev->dev, "unable to get UART clock\n");
884 return PTR_ERR(mvuart->clk);
885 }
886 } else {
887 if (!clk_prepare_enable(mvuart->clk))
888 port->uartclk = clk_get_rate(mvuart->clk);
889 }
890
891 /* Manage interrupts */
892 if (platform_irq_count(pdev) == 1) {
893 /* Old bindings: no name on the single unamed UART0 IRQ */
894 irq = platform_get_irq(pdev, 0);
895 if (irq < 0)
896 return irq;
897
898 mvuart->irq[UART_IRQ_SUM] = irq;
899 } else {
900 /*
901 * New bindings: named interrupts (RX, TX) for both UARTS,
902 * only make use of uart-rx and uart-tx interrupts, do not use
903 * uart-sum of UART0 port.
904 */
905 irq = platform_get_irq_byname(pdev, "uart-rx");
906 if (irq < 0)
907 return irq;
908
909 mvuart->irq[UART_RX_IRQ] = irq;
910
911 irq = platform_get_irq_byname(pdev, "uart-tx");
912 if (irq < 0)
913 return irq;
914
915 mvuart->irq[UART_TX_IRQ] = irq;
916 }
917
918 /* UART Soft Reset*/
919 writel(CTRL_SOFT_RST, port->membase + UART_CTRL(port));
920 udelay(1);
921 writel(0, port->membase + UART_CTRL(port));
922
923 return uart_add_one_port(&mvebu_uart_driver, port);
924 }
925
926 static struct mvebu_uart_driver_data uart_std_driver_data = {
927 .is_ext = false,
928 .regs.rbr = UART_STD_RBR,
929 .regs.tsh = UART_STD_TSH,
930 .regs.ctrl = UART_STD_CTRL1,
931 .regs.intr = UART_STD_CTRL2,
932 .flags.ctrl_tx_rdy_int = CTRL_STD_TX_RDY_INT,
933 .flags.ctrl_rx_rdy_int = CTRL_STD_RX_RDY_INT,
934 .flags.stat_tx_rdy = STAT_STD_TX_RDY,
935 .flags.stat_rx_rdy = STAT_STD_RX_RDY,
936 };
937
938 static struct mvebu_uart_driver_data uart_ext_driver_data = {
939 .is_ext = true,
940 .regs.rbr = UART_EXT_RBR,
941 .regs.tsh = UART_EXT_TSH,
942 .regs.ctrl = UART_EXT_CTRL1,
943 .regs.intr = UART_EXT_CTRL2,
944 .flags.ctrl_tx_rdy_int = CTRL_EXT_TX_RDY_INT,
945 .flags.ctrl_rx_rdy_int = CTRL_EXT_RX_RDY_INT,
946 .flags.stat_tx_rdy = STAT_EXT_TX_RDY,
947 .flags.stat_rx_rdy = STAT_EXT_RX_RDY,
948 };
949
950 /* Match table for of_platform binding */
951 static const struct of_device_id mvebu_uart_of_match[] = {
952 {
953 .compatible = "marvell,armada-3700-uart",
954 .data = (void *)&uart_std_driver_data,
955 },
956 {
957 .compatible = "marvell,armada-3700-uart-ext",
958 .data = (void *)&uart_ext_driver_data,
959 },
960 {}
961 };
962
963 static struct platform_driver mvebu_uart_platform_driver = {
964 .probe = mvebu_uart_probe,
965 .driver = {
966 .name = "mvebu-uart",
967 .of_match_table = of_match_ptr(mvebu_uart_of_match),
968 .suppress_bind_attrs = true,
969 #if defined(CONFIG_PM)
970 .pm = &mvebu_uart_pm_ops,
971 #endif /* CONFIG_PM */
972 },
973 };
974
mvebu_uart_init(void)975 static int __init mvebu_uart_init(void)
976 {
977 int ret;
978
979 ret = uart_register_driver(&mvebu_uart_driver);
980 if (ret)
981 return ret;
982
983 ret = platform_driver_register(&mvebu_uart_platform_driver);
984 if (ret)
985 uart_unregister_driver(&mvebu_uart_driver);
986
987 return ret;
988 }
989 arch_initcall(mvebu_uart_init);
990