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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
d57f341b GJ |
2 | /* |
3 | * Atheros AR933X SoC built-in UART driver | |
4 | * | |
5 | * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> | |
6 | * | |
7 | * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. | |
d57f341b GJ |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/ioport.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/console.h> | |
14 | #include <linux/sysrq.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/platform_device.h> | |
dd910d98 GJ |
17 | #include <linux/of.h> |
18 | #include <linux/of_platform.h> | |
d57f341b GJ |
19 | #include <linux/tty.h> |
20 | #include <linux/tty_flip.h> | |
21 | #include <linux/serial_core.h> | |
22 | #include <linux/serial.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/io.h> | |
25 | #include <linux/irq.h> | |
15ef17f6 | 26 | #include <linux/clk.h> |
d57f341b | 27 | |
2dff8ad9 GJ |
28 | #include <asm/div64.h> |
29 | ||
d57f341b | 30 | #include <asm/mach-ath79/ar933x_uart.h> |
d57f341b GJ |
31 | |
32 | #define DRIVER_NAME "ar933x-uart" | |
33 | ||
2dff8ad9 GJ |
34 | #define AR933X_UART_MAX_SCALE 0xff |
35 | #define AR933X_UART_MAX_STEP 0xffff | |
36 | ||
37 | #define AR933X_UART_MIN_BAUD 300 | |
38 | #define AR933X_UART_MAX_BAUD 3000000 | |
39 | ||
d57f341b GJ |
40 | #define AR933X_DUMMY_STATUS_RD 0x01 |
41 | ||
42 | static struct uart_driver ar933x_uart_driver; | |
43 | ||
44 | struct ar933x_uart_port { | |
45 | struct uart_port port; | |
46 | unsigned int ier; /* shadow Interrupt Enable Register */ | |
2dff8ad9 GJ |
47 | unsigned int min_baud; |
48 | unsigned int max_baud; | |
15ef17f6 | 49 | struct clk *clk; |
d57f341b GJ |
50 | }; |
51 | ||
12415535 GJ |
52 | static inline bool ar933x_uart_console_enabled(void) |
53 | { | |
97f2645f | 54 | return IS_ENABLED(CONFIG_SERIAL_AR933X_CONSOLE); |
12415535 GJ |
55 | } |
56 | ||
d57f341b GJ |
57 | static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up, |
58 | int offset) | |
59 | { | |
60 | return readl(up->port.membase + offset); | |
61 | } | |
62 | ||
63 | static inline void ar933x_uart_write(struct ar933x_uart_port *up, | |
64 | int offset, unsigned int value) | |
65 | { | |
66 | writel(value, up->port.membase + offset); | |
67 | } | |
68 | ||
69 | static inline void ar933x_uart_rmw(struct ar933x_uart_port *up, | |
70 | unsigned int offset, | |
71 | unsigned int mask, | |
72 | unsigned int val) | |
73 | { | |
74 | unsigned int t; | |
75 | ||
76 | t = ar933x_uart_read(up, offset); | |
77 | t &= ~mask; | |
78 | t |= val; | |
79 | ar933x_uart_write(up, offset, t); | |
80 | } | |
81 | ||
82 | static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up, | |
83 | unsigned int offset, | |
84 | unsigned int val) | |
85 | { | |
86 | ar933x_uart_rmw(up, offset, 0, val); | |
87 | } | |
88 | ||
89 | static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up, | |
90 | unsigned int offset, | |
91 | unsigned int val) | |
92 | { | |
93 | ar933x_uart_rmw(up, offset, val, 0); | |
94 | } | |
95 | ||
96 | static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up) | |
97 | { | |
98 | up->ier |= AR933X_UART_INT_TX_EMPTY; | |
99 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); | |
100 | } | |
101 | ||
102 | static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up) | |
103 | { | |
104 | up->ier &= ~AR933X_UART_INT_TX_EMPTY; | |
105 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); | |
106 | } | |
107 | ||
108 | static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch) | |
109 | { | |
110 | unsigned int rdata; | |
111 | ||
112 | rdata = ch & AR933X_UART_DATA_TX_RX_MASK; | |
113 | rdata |= AR933X_UART_DATA_TX_CSR; | |
114 | ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata); | |
115 | } | |
116 | ||
117 | static unsigned int ar933x_uart_tx_empty(struct uart_port *port) | |
118 | { | |
f9c1b28e FF |
119 | struct ar933x_uart_port *up = |
120 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
121 | unsigned long flags; |
122 | unsigned int rdata; | |
123 | ||
124 | spin_lock_irqsave(&up->port.lock, flags); | |
125 | rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); | |
126 | spin_unlock_irqrestore(&up->port.lock, flags); | |
127 | ||
128 | return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT; | |
129 | } | |
130 | ||
131 | static unsigned int ar933x_uart_get_mctrl(struct uart_port *port) | |
132 | { | |
133 | return TIOCM_CAR; | |
134 | } | |
135 | ||
136 | static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
137 | { | |
138 | } | |
139 | ||
140 | static void ar933x_uart_start_tx(struct uart_port *port) | |
141 | { | |
f9c1b28e FF |
142 | struct ar933x_uart_port *up = |
143 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
144 | |
145 | ar933x_uart_start_tx_interrupt(up); | |
146 | } | |
147 | ||
148 | static void ar933x_uart_stop_tx(struct uart_port *port) | |
149 | { | |
f9c1b28e FF |
150 | struct ar933x_uart_port *up = |
151 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
152 | |
153 | ar933x_uart_stop_tx_interrupt(up); | |
154 | } | |
155 | ||
156 | static void ar933x_uart_stop_rx(struct uart_port *port) | |
157 | { | |
f9c1b28e FF |
158 | struct ar933x_uart_port *up = |
159 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
160 | |
161 | up->ier &= ~AR933X_UART_INT_RX_VALID; | |
162 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); | |
163 | } | |
164 | ||
165 | static void ar933x_uart_break_ctl(struct uart_port *port, int break_state) | |
166 | { | |
f9c1b28e FF |
167 | struct ar933x_uart_port *up = |
168 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
169 | unsigned long flags; |
170 | ||
171 | spin_lock_irqsave(&up->port.lock, flags); | |
172 | if (break_state == -1) | |
173 | ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, | |
174 | AR933X_UART_CS_TX_BREAK); | |
175 | else | |
176 | ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, | |
177 | AR933X_UART_CS_TX_BREAK); | |
178 | spin_unlock_irqrestore(&up->port.lock, flags); | |
179 | } | |
180 | ||
2dff8ad9 GJ |
181 | /* |
182 | * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17)) | |
183 | */ | |
184 | static unsigned long ar933x_uart_get_baud(unsigned int clk, | |
185 | unsigned int scale, | |
186 | unsigned int step) | |
187 | { | |
188 | u64 t; | |
189 | u32 div; | |
190 | ||
191 | div = (2 << 16) * (scale + 1); | |
192 | t = clk; | |
193 | t *= step; | |
194 | t += (div / 2); | |
195 | do_div(t, div); | |
196 | ||
197 | return t; | |
198 | } | |
199 | ||
200 | static void ar933x_uart_get_scale_step(unsigned int clk, | |
201 | unsigned int baud, | |
202 | unsigned int *scale, | |
203 | unsigned int *step) | |
204 | { | |
205 | unsigned int tscale; | |
206 | long min_diff; | |
207 | ||
208 | *scale = 0; | |
209 | *step = 0; | |
210 | ||
211 | min_diff = baud; | |
212 | for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) { | |
213 | u64 tstep; | |
214 | int diff; | |
215 | ||
216 | tstep = baud * (tscale + 1); | |
217 | tstep *= (2 << 16); | |
218 | do_div(tstep, clk); | |
219 | ||
220 | if (tstep > AR933X_UART_MAX_STEP) | |
221 | break; | |
222 | ||
223 | diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud); | |
224 | if (diff < min_diff) { | |
225 | min_diff = diff; | |
226 | *scale = tscale; | |
227 | *step = tstep; | |
228 | } | |
229 | } | |
230 | } | |
231 | ||
d57f341b GJ |
232 | static void ar933x_uart_set_termios(struct uart_port *port, |
233 | struct ktermios *new, | |
234 | struct ktermios *old) | |
235 | { | |
f9c1b28e FF |
236 | struct ar933x_uart_port *up = |
237 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
238 | unsigned int cs; |
239 | unsigned long flags; | |
2dff8ad9 | 240 | unsigned int baud, scale, step; |
d57f341b GJ |
241 | |
242 | /* Only CS8 is supported */ | |
243 | new->c_cflag &= ~CSIZE; | |
244 | new->c_cflag |= CS8; | |
245 | ||
246 | /* Only one stop bit is supported */ | |
247 | new->c_cflag &= ~CSTOPB; | |
248 | ||
249 | cs = 0; | |
250 | if (new->c_cflag & PARENB) { | |
251 | if (!(new->c_cflag & PARODD)) | |
252 | cs |= AR933X_UART_CS_PARITY_EVEN; | |
253 | else | |
254 | cs |= AR933X_UART_CS_PARITY_ODD; | |
255 | } else { | |
256 | cs |= AR933X_UART_CS_PARITY_NONE; | |
257 | } | |
258 | ||
259 | /* Mark/space parity is not supported */ | |
260 | new->c_cflag &= ~CMSPAR; | |
261 | ||
2dff8ad9 GJ |
262 | baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud); |
263 | ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step); | |
d57f341b GJ |
264 | |
265 | /* | |
266 | * Ok, we're now changing the port state. Do it with | |
267 | * interrupts disabled. | |
268 | */ | |
269 | spin_lock_irqsave(&up->port.lock, flags); | |
270 | ||
2dff8ad9 GJ |
271 | /* disable the UART */ |
272 | ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, | |
273 | AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S); | |
274 | ||
d57f341b GJ |
275 | /* Update the per-port timeout. */ |
276 | uart_update_timeout(port, new->c_cflag, baud); | |
277 | ||
278 | up->port.ignore_status_mask = 0; | |
279 | ||
280 | /* ignore all characters if CREAD is not set */ | |
281 | if ((new->c_cflag & CREAD) == 0) | |
282 | up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD; | |
283 | ||
284 | ar933x_uart_write(up, AR933X_UART_CLOCK_REG, | |
2dff8ad9 | 285 | scale << AR933X_UART_CLOCK_SCALE_S | step); |
d57f341b GJ |
286 | |
287 | /* setup configuration register */ | |
288 | ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs); | |
289 | ||
290 | /* enable host interrupt */ | |
291 | ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, | |
292 | AR933X_UART_CS_HOST_INT_EN); | |
293 | ||
2dff8ad9 GJ |
294 | /* reenable the UART */ |
295 | ar933x_uart_rmw(up, AR933X_UART_CS_REG, | |
296 | AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S, | |
297 | AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S); | |
298 | ||
d57f341b GJ |
299 | spin_unlock_irqrestore(&up->port.lock, flags); |
300 | ||
301 | if (tty_termios_baud_rate(new)) | |
302 | tty_termios_encode_baud_rate(new, baud, baud); | |
303 | } | |
304 | ||
305 | static void ar933x_uart_rx_chars(struct ar933x_uart_port *up) | |
306 | { | |
92a19f9c | 307 | struct tty_port *port = &up->port.state->port; |
d57f341b GJ |
308 | int max_count = 256; |
309 | ||
d57f341b GJ |
310 | do { |
311 | unsigned int rdata; | |
312 | unsigned char ch; | |
313 | ||
314 | rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); | |
315 | if ((rdata & AR933X_UART_DATA_RX_CSR) == 0) | |
316 | break; | |
317 | ||
318 | /* remove the character from the FIFO */ | |
319 | ar933x_uart_write(up, AR933X_UART_DATA_REG, | |
320 | AR933X_UART_DATA_RX_CSR); | |
321 | ||
d57f341b GJ |
322 | up->port.icount.rx++; |
323 | ch = rdata & AR933X_UART_DATA_TX_RX_MASK; | |
324 | ||
325 | if (uart_handle_sysrq_char(&up->port, ch)) | |
326 | continue; | |
327 | ||
328 | if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0) | |
92a19f9c | 329 | tty_insert_flip_char(port, ch, TTY_NORMAL); |
d57f341b GJ |
330 | } while (max_count-- > 0); |
331 | ||
b16c8e3e | 332 | spin_unlock(&up->port.lock); |
2e124b4a | 333 | tty_flip_buffer_push(port); |
b16c8e3e | 334 | spin_lock(&up->port.lock); |
d57f341b GJ |
335 | } |
336 | ||
337 | static void ar933x_uart_tx_chars(struct ar933x_uart_port *up) | |
338 | { | |
339 | struct circ_buf *xmit = &up->port.state->xmit; | |
340 | int count; | |
341 | ||
342 | if (uart_tx_stopped(&up->port)) | |
343 | return; | |
344 | ||
345 | count = up->port.fifosize; | |
346 | do { | |
347 | unsigned int rdata; | |
348 | ||
349 | rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); | |
350 | if ((rdata & AR933X_UART_DATA_TX_CSR) == 0) | |
351 | break; | |
352 | ||
353 | if (up->port.x_char) { | |
354 | ar933x_uart_putc(up, up->port.x_char); | |
355 | up->port.icount.tx++; | |
356 | up->port.x_char = 0; | |
357 | continue; | |
358 | } | |
359 | ||
360 | if (uart_circ_empty(xmit)) | |
361 | break; | |
362 | ||
363 | ar933x_uart_putc(up, xmit->buf[xmit->tail]); | |
364 | ||
365 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
366 | up->port.icount.tx++; | |
367 | } while (--count > 0); | |
368 | ||
369 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
370 | uart_write_wakeup(&up->port); | |
371 | ||
372 | if (!uart_circ_empty(xmit)) | |
373 | ar933x_uart_start_tx_interrupt(up); | |
374 | } | |
375 | ||
376 | static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id) | |
377 | { | |
378 | struct ar933x_uart_port *up = dev_id; | |
379 | unsigned int status; | |
380 | ||
381 | status = ar933x_uart_read(up, AR933X_UART_CS_REG); | |
382 | if ((status & AR933X_UART_CS_HOST_INT) == 0) | |
383 | return IRQ_NONE; | |
384 | ||
385 | spin_lock(&up->port.lock); | |
386 | ||
387 | status = ar933x_uart_read(up, AR933X_UART_INT_REG); | |
388 | status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG); | |
389 | ||
390 | if (status & AR933X_UART_INT_RX_VALID) { | |
391 | ar933x_uart_write(up, AR933X_UART_INT_REG, | |
392 | AR933X_UART_INT_RX_VALID); | |
393 | ar933x_uart_rx_chars(up); | |
394 | } | |
395 | ||
396 | if (status & AR933X_UART_INT_TX_EMPTY) { | |
397 | ar933x_uart_write(up, AR933X_UART_INT_REG, | |
398 | AR933X_UART_INT_TX_EMPTY); | |
399 | ar933x_uart_stop_tx_interrupt(up); | |
400 | ar933x_uart_tx_chars(up); | |
401 | } | |
402 | ||
403 | spin_unlock(&up->port.lock); | |
404 | ||
405 | return IRQ_HANDLED; | |
406 | } | |
407 | ||
408 | static int ar933x_uart_startup(struct uart_port *port) | |
409 | { | |
f9c1b28e FF |
410 | struct ar933x_uart_port *up = |
411 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
412 | unsigned long flags; |
413 | int ret; | |
414 | ||
415 | ret = request_irq(up->port.irq, ar933x_uart_interrupt, | |
416 | up->port.irqflags, dev_name(up->port.dev), up); | |
417 | if (ret) | |
418 | return ret; | |
419 | ||
420 | spin_lock_irqsave(&up->port.lock, flags); | |
421 | ||
422 | /* Enable HOST interrupts */ | |
423 | ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, | |
424 | AR933X_UART_CS_HOST_INT_EN); | |
425 | ||
426 | /* Enable RX interrupts */ | |
427 | up->ier = AR933X_UART_INT_RX_VALID; | |
428 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); | |
429 | ||
430 | spin_unlock_irqrestore(&up->port.lock, flags); | |
431 | ||
432 | return 0; | |
433 | } | |
434 | ||
435 | static void ar933x_uart_shutdown(struct uart_port *port) | |
436 | { | |
f9c1b28e FF |
437 | struct ar933x_uart_port *up = |
438 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
439 | |
440 | /* Disable all interrupts */ | |
441 | up->ier = 0; | |
442 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); | |
443 | ||
444 | /* Disable break condition */ | |
445 | ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, | |
446 | AR933X_UART_CS_TX_BREAK); | |
447 | ||
448 | free_irq(up->port.irq, up); | |
449 | } | |
450 | ||
451 | static const char *ar933x_uart_type(struct uart_port *port) | |
452 | { | |
453 | return (port->type == PORT_AR933X) ? "AR933X UART" : NULL; | |
454 | } | |
455 | ||
456 | static void ar933x_uart_release_port(struct uart_port *port) | |
457 | { | |
458 | /* Nothing to release ... */ | |
459 | } | |
460 | ||
461 | static int ar933x_uart_request_port(struct uart_port *port) | |
462 | { | |
463 | /* UARTs always present */ | |
464 | return 0; | |
465 | } | |
466 | ||
467 | static void ar933x_uart_config_port(struct uart_port *port, int flags) | |
468 | { | |
469 | if (flags & UART_CONFIG_TYPE) | |
470 | port->type = PORT_AR933X; | |
471 | } | |
472 | ||
473 | static int ar933x_uart_verify_port(struct uart_port *port, | |
474 | struct serial_struct *ser) | |
475 | { | |
f9c1b28e FF |
476 | struct ar933x_uart_port *up = |
477 | container_of(port, struct ar933x_uart_port, port); | |
2dff8ad9 | 478 | |
d57f341b GJ |
479 | if (ser->type != PORT_UNKNOWN && |
480 | ser->type != PORT_AR933X) | |
481 | return -EINVAL; | |
482 | ||
483 | if (ser->irq < 0 || ser->irq >= NR_IRQS) | |
484 | return -EINVAL; | |
485 | ||
2dff8ad9 GJ |
486 | if (ser->baud_base < up->min_baud || |
487 | ser->baud_base > up->max_baud) | |
d57f341b GJ |
488 | return -EINVAL; |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
2331e068 | 493 | static const struct uart_ops ar933x_uart_ops = { |
d57f341b GJ |
494 | .tx_empty = ar933x_uart_tx_empty, |
495 | .set_mctrl = ar933x_uart_set_mctrl, | |
496 | .get_mctrl = ar933x_uart_get_mctrl, | |
497 | .stop_tx = ar933x_uart_stop_tx, | |
498 | .start_tx = ar933x_uart_start_tx, | |
499 | .stop_rx = ar933x_uart_stop_rx, | |
d57f341b GJ |
500 | .break_ctl = ar933x_uart_break_ctl, |
501 | .startup = ar933x_uart_startup, | |
502 | .shutdown = ar933x_uart_shutdown, | |
503 | .set_termios = ar933x_uart_set_termios, | |
504 | .type = ar933x_uart_type, | |
505 | .release_port = ar933x_uart_release_port, | |
506 | .request_port = ar933x_uart_request_port, | |
507 | .config_port = ar933x_uart_config_port, | |
508 | .verify_port = ar933x_uart_verify_port, | |
509 | }; | |
510 | ||
d57f341b GJ |
511 | static struct ar933x_uart_port * |
512 | ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS]; | |
513 | ||
514 | static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up) | |
515 | { | |
516 | unsigned int status; | |
517 | unsigned int timeout = 60000; | |
518 | ||
519 | /* Wait up to 60ms for the character(s) to be sent. */ | |
520 | do { | |
521 | status = ar933x_uart_read(up, AR933X_UART_DATA_REG); | |
522 | if (--timeout == 0) | |
523 | break; | |
524 | udelay(1); | |
525 | } while ((status & AR933X_UART_DATA_TX_CSR) == 0); | |
526 | } | |
527 | ||
528 | static void ar933x_uart_console_putchar(struct uart_port *port, int ch) | |
529 | { | |
f9c1b28e FF |
530 | struct ar933x_uart_port *up = |
531 | container_of(port, struct ar933x_uart_port, port); | |
d57f341b GJ |
532 | |
533 | ar933x_uart_wait_xmitr(up); | |
534 | ar933x_uart_putc(up, ch); | |
535 | } | |
536 | ||
537 | static void ar933x_uart_console_write(struct console *co, const char *s, | |
538 | unsigned int count) | |
539 | { | |
540 | struct ar933x_uart_port *up = ar933x_console_ports[co->index]; | |
541 | unsigned long flags; | |
542 | unsigned int int_en; | |
543 | int locked = 1; | |
544 | ||
545 | local_irq_save(flags); | |
546 | ||
547 | if (up->port.sysrq) | |
548 | locked = 0; | |
549 | else if (oops_in_progress) | |
550 | locked = spin_trylock(&up->port.lock); | |
551 | else | |
552 | spin_lock(&up->port.lock); | |
553 | ||
554 | /* | |
555 | * First save the IER then disable the interrupts | |
556 | */ | |
557 | int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG); | |
558 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0); | |
559 | ||
560 | uart_console_write(&up->port, s, count, ar933x_uart_console_putchar); | |
561 | ||
562 | /* | |
563 | * Finally, wait for transmitter to become empty | |
564 | * and restore the IER | |
565 | */ | |
566 | ar933x_uart_wait_xmitr(up); | |
567 | ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en); | |
568 | ||
569 | ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS); | |
570 | ||
571 | if (locked) | |
572 | spin_unlock(&up->port.lock); | |
573 | ||
574 | local_irq_restore(flags); | |
575 | } | |
576 | ||
577 | static int ar933x_uart_console_setup(struct console *co, char *options) | |
578 | { | |
579 | struct ar933x_uart_port *up; | |
580 | int baud = 115200; | |
581 | int bits = 8; | |
582 | int parity = 'n'; | |
583 | int flow = 'n'; | |
584 | ||
585 | if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS) | |
586 | return -EINVAL; | |
587 | ||
588 | up = ar933x_console_ports[co->index]; | |
589 | if (!up) | |
590 | return -ENODEV; | |
591 | ||
592 | if (options) | |
593 | uart_parse_options(options, &baud, &parity, &bits, &flow); | |
594 | ||
595 | return uart_set_options(&up->port, co, baud, parity, bits, flow); | |
596 | } | |
597 | ||
598 | static struct console ar933x_uart_console = { | |
599 | .name = "ttyATH", | |
600 | .write = ar933x_uart_console_write, | |
601 | .device = uart_console_device, | |
602 | .setup = ar933x_uart_console_setup, | |
603 | .flags = CON_PRINTBUFFER, | |
604 | .index = -1, | |
605 | .data = &ar933x_uart_driver, | |
606 | }; | |
607 | ||
608 | static void ar933x_uart_add_console_port(struct ar933x_uart_port *up) | |
609 | { | |
12415535 GJ |
610 | if (!ar933x_uart_console_enabled()) |
611 | return; | |
612 | ||
d57f341b GJ |
613 | ar933x_console_ports[up->port.line] = up; |
614 | } | |
615 | ||
d57f341b GJ |
616 | static struct uart_driver ar933x_uart_driver = { |
617 | .owner = THIS_MODULE, | |
618 | .driver_name = DRIVER_NAME, | |
619 | .dev_name = "ttyATH", | |
620 | .nr = CONFIG_SERIAL_AR933X_NR_UARTS, | |
12415535 | 621 | .cons = NULL, /* filled in runtime */ |
d57f341b GJ |
622 | }; |
623 | ||
9671f099 | 624 | static int ar933x_uart_probe(struct platform_device *pdev) |
d57f341b | 625 | { |
d57f341b GJ |
626 | struct ar933x_uart_port *up; |
627 | struct uart_port *port; | |
628 | struct resource *mem_res; | |
629 | struct resource *irq_res; | |
dd910d98 | 630 | struct device_node *np; |
2dff8ad9 | 631 | unsigned int baud; |
d57f341b GJ |
632 | int id; |
633 | int ret; | |
634 | ||
dd910d98 | 635 | np = pdev->dev.of_node; |
97f2645f | 636 | if (IS_ENABLED(CONFIG_OF) && np) { |
dd910d98 GJ |
637 | id = of_alias_get_id(np, "serial"); |
638 | if (id < 0) { | |
639 | dev_err(&pdev->dev, "unable to get alias id, err=%d\n", | |
640 | id); | |
641 | return id; | |
642 | } | |
643 | } else { | |
644 | id = pdev->id; | |
645 | if (id == -1) | |
646 | id = 0; | |
647 | } | |
d57f341b | 648 | |
bb8478d7 | 649 | if (id >= CONFIG_SERIAL_AR933X_NR_UARTS) |
d57f341b GJ |
650 | return -EINVAL; |
651 | ||
d57f341b GJ |
652 | irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
653 | if (!irq_res) { | |
654 | dev_err(&pdev->dev, "no IRQ resource\n"); | |
655 | return -EINVAL; | |
656 | } | |
657 | ||
a324e4de GJ |
658 | up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port), |
659 | GFP_KERNEL); | |
d57f341b GJ |
660 | if (!up) |
661 | return -ENOMEM; | |
662 | ||
15ef17f6 GJ |
663 | up->clk = devm_clk_get(&pdev->dev, "uart"); |
664 | if (IS_ERR(up->clk)) { | |
665 | dev_err(&pdev->dev, "unable to get UART clock\n"); | |
666 | return PTR_ERR(up->clk); | |
667 | } | |
668 | ||
d57f341b | 669 | port = &up->port; |
d57f341b | 670 | |
071eb0ff | 671 | mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
a324e4de GJ |
672 | port->membase = devm_ioremap_resource(&pdev->dev, mem_res); |
673 | if (IS_ERR(port->membase)) | |
674 | return PTR_ERR(port->membase); | |
d57f341b | 675 | |
15ef17f6 GJ |
676 | ret = clk_prepare_enable(up->clk); |
677 | if (ret) | |
678 | return ret; | |
679 | ||
680 | port->uartclk = clk_get_rate(up->clk); | |
681 | if (!port->uartclk) { | |
682 | ret = -EINVAL; | |
683 | goto err_disable_clk; | |
684 | } | |
685 | ||
a324e4de | 686 | port->mapbase = mem_res->start; |
d57f341b GJ |
687 | port->line = id; |
688 | port->irq = irq_res->start; | |
689 | port->dev = &pdev->dev; | |
690 | port->type = PORT_AR933X; | |
691 | port->iotype = UPIO_MEM32; | |
d57f341b GJ |
692 | |
693 | port->regshift = 2; | |
694 | port->fifosize = AR933X_UART_FIFO_SIZE; | |
695 | port->ops = &ar933x_uart_ops; | |
696 | ||
2dff8ad9 GJ |
697 | baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1); |
698 | up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD); | |
699 | ||
700 | baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP); | |
701 | up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD); | |
702 | ||
d57f341b GJ |
703 | ar933x_uart_add_console_port(up); |
704 | ||
705 | ret = uart_add_one_port(&ar933x_uart_driver, &up->port); | |
706 | if (ret) | |
15ef17f6 | 707 | goto err_disable_clk; |
d57f341b GJ |
708 | |
709 | platform_set_drvdata(pdev, up); | |
710 | return 0; | |
15ef17f6 GJ |
711 | |
712 | err_disable_clk: | |
713 | clk_disable_unprepare(up->clk); | |
714 | return ret; | |
d57f341b GJ |
715 | } |
716 | ||
ae8d8a14 | 717 | static int ar933x_uart_remove(struct platform_device *pdev) |
d57f341b GJ |
718 | { |
719 | struct ar933x_uart_port *up; | |
720 | ||
721 | up = platform_get_drvdata(pdev); | |
d57f341b | 722 | |
15ef17f6 | 723 | if (up) { |
d57f341b | 724 | uart_remove_one_port(&ar933x_uart_driver, &up->port); |
15ef17f6 GJ |
725 | clk_disable_unprepare(up->clk); |
726 | } | |
d57f341b GJ |
727 | |
728 | return 0; | |
729 | } | |
730 | ||
dd910d98 GJ |
731 | #ifdef CONFIG_OF |
732 | static const struct of_device_id ar933x_uart_of_ids[] = { | |
733 | { .compatible = "qca,ar9330-uart" }, | |
734 | {}, | |
735 | }; | |
736 | MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids); | |
737 | #endif | |
738 | ||
d57f341b GJ |
739 | static struct platform_driver ar933x_uart_platform_driver = { |
740 | .probe = ar933x_uart_probe, | |
2d47b716 | 741 | .remove = ar933x_uart_remove, |
d57f341b GJ |
742 | .driver = { |
743 | .name = DRIVER_NAME, | |
dd910d98 | 744 | .of_match_table = of_match_ptr(ar933x_uart_of_ids), |
d57f341b GJ |
745 | }, |
746 | }; | |
747 | ||
748 | static int __init ar933x_uart_init(void) | |
749 | { | |
750 | int ret; | |
751 | ||
12415535 GJ |
752 | if (ar933x_uart_console_enabled()) |
753 | ar933x_uart_driver.cons = &ar933x_uart_console; | |
754 | ||
d57f341b GJ |
755 | ret = uart_register_driver(&ar933x_uart_driver); |
756 | if (ret) | |
757 | goto err_out; | |
758 | ||
759 | ret = platform_driver_register(&ar933x_uart_platform_driver); | |
760 | if (ret) | |
761 | goto err_unregister_uart_driver; | |
762 | ||
763 | return 0; | |
764 | ||
765 | err_unregister_uart_driver: | |
766 | uart_unregister_driver(&ar933x_uart_driver); | |
767 | err_out: | |
768 | return ret; | |
769 | } | |
770 | ||
771 | static void __exit ar933x_uart_exit(void) | |
772 | { | |
773 | platform_driver_unregister(&ar933x_uart_platform_driver); | |
774 | uart_unregister_driver(&ar933x_uart_driver); | |
775 | } | |
776 | ||
777 | module_init(ar933x_uart_init); | |
778 | module_exit(ar933x_uart_exit); | |
779 | ||
780 | MODULE_DESCRIPTION("Atheros AR933X UART driver"); | |
781 | MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); | |
782 | MODULE_LICENSE("GPL v2"); | |
783 | MODULE_ALIAS("platform:" DRIVER_NAME); |