1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * RDA8810PL serial device driver
4 *
5 * Copyright RDA Microelectronics Company Limited
6 * Copyright (c) 2017 Andreas Färber
7 * Copyright (c) 2018 Manivannan Sadhasivam
8 */
9
10 #include <linux/clk.h>
11 #include <linux/console.h>
12 #include <linux/delay.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/serial.h>
18 #include <linux/serial_core.h>
19 #include <linux/tty.h>
20 #include <linux/tty_flip.h>
21
22 #define RDA_UART_PORT_NUM 3
23 #define RDA_UART_DEV_NAME "ttyRDA"
24
25 #define RDA_UART_CTRL 0x00
26 #define RDA_UART_STATUS 0x04
27 #define RDA_UART_RXTX_BUFFER 0x08
28 #define RDA_UART_IRQ_MASK 0x0c
29 #define RDA_UART_IRQ_CAUSE 0x10
30 #define RDA_UART_IRQ_TRIGGERS 0x14
31 #define RDA_UART_CMD_SET 0x18
32 #define RDA_UART_CMD_CLR 0x1c
33
34 /* UART_CTRL Bits */
35 #define RDA_UART_ENABLE BIT(0)
36 #define RDA_UART_DBITS_8 BIT(1)
37 #define RDA_UART_TX_SBITS_2 BIT(2)
38 #define RDA_UART_PARITY_EN BIT(3)
39 #define RDA_UART_PARITY(x) (((x) & 0x3) << 4)
40 #define RDA_UART_PARITY_ODD RDA_UART_PARITY(0)
41 #define RDA_UART_PARITY_EVEN RDA_UART_PARITY(1)
42 #define RDA_UART_PARITY_SPACE RDA_UART_PARITY(2)
43 #define RDA_UART_PARITY_MARK RDA_UART_PARITY(3)
44 #define RDA_UART_DIV_MODE BIT(20)
45 #define RDA_UART_IRDA_EN BIT(21)
46 #define RDA_UART_DMA_EN BIT(22)
47 #define RDA_UART_FLOW_CNT_EN BIT(23)
48 #define RDA_UART_LOOP_BACK_EN BIT(24)
49 #define RDA_UART_RX_LOCK_ERR BIT(25)
50 #define RDA_UART_RX_BREAK_LEN(x) (((x) & 0xf) << 28)
51
52 /* UART_STATUS Bits */
53 #define RDA_UART_RX_FIFO(x) (((x) & 0x7f) << 0)
54 #define RDA_UART_RX_FIFO_MASK (0x7f << 0)
55 #define RDA_UART_TX_FIFO(x) (((x) & 0x1f) << 8)
56 #define RDA_UART_TX_FIFO_MASK (0x1f << 8)
57 #define RDA_UART_TX_ACTIVE BIT(14)
58 #define RDA_UART_RX_ACTIVE BIT(15)
59 #define RDA_UART_RX_OVERFLOW_ERR BIT(16)
60 #define RDA_UART_TX_OVERFLOW_ERR BIT(17)
61 #define RDA_UART_RX_PARITY_ERR BIT(18)
62 #define RDA_UART_RX_FRAMING_ERR BIT(19)
63 #define RDA_UART_RX_BREAK_INT BIT(20)
64 #define RDA_UART_DCTS BIT(24)
65 #define RDA_UART_CTS BIT(25)
66 #define RDA_UART_DTR BIT(28)
67 #define RDA_UART_CLK_ENABLED BIT(31)
68
69 /* UART_RXTX_BUFFER Bits */
70 #define RDA_UART_RX_DATA(x) (((x) & 0xff) << 0)
71 #define RDA_UART_TX_DATA(x) (((x) & 0xff) << 0)
72
73 /* UART_IRQ_MASK Bits */
74 #define RDA_UART_TX_MODEM_STATUS BIT(0)
75 #define RDA_UART_RX_DATA_AVAILABLE BIT(1)
76 #define RDA_UART_TX_DATA_NEEDED BIT(2)
77 #define RDA_UART_RX_TIMEOUT BIT(3)
78 #define RDA_UART_RX_LINE_ERR BIT(4)
79 #define RDA_UART_TX_DMA_DONE BIT(5)
80 #define RDA_UART_RX_DMA_DONE BIT(6)
81 #define RDA_UART_RX_DMA_TIMEOUT BIT(7)
82 #define RDA_UART_DTR_RISE BIT(8)
83 #define RDA_UART_DTR_FALL BIT(9)
84
85 /* UART_IRQ_CAUSE Bits */
86 #define RDA_UART_TX_MODEM_STATUS_U BIT(16)
87 #define RDA_UART_RX_DATA_AVAILABLE_U BIT(17)
88 #define RDA_UART_TX_DATA_NEEDED_U BIT(18)
89 #define RDA_UART_RX_TIMEOUT_U BIT(19)
90 #define RDA_UART_RX_LINE_ERR_U BIT(20)
91 #define RDA_UART_TX_DMA_DONE_U BIT(21)
92 #define RDA_UART_RX_DMA_DONE_U BIT(22)
93 #define RDA_UART_RX_DMA_TIMEOUT_U BIT(23)
94 #define RDA_UART_DTR_RISE_U BIT(24)
95 #define RDA_UART_DTR_FALL_U BIT(25)
96
97 /* UART_TRIGGERS Bits */
98 #define RDA_UART_RX_TRIGGER(x) (((x) & 0x1f) << 0)
99 #define RDA_UART_TX_TRIGGER(x) (((x) & 0xf) << 8)
100 #define RDA_UART_AFC_LEVEL(x) (((x) & 0x1f) << 16)
101
102 /* UART_CMD_SET Bits */
103 #define RDA_UART_RI BIT(0)
104 #define RDA_UART_DCD BIT(1)
105 #define RDA_UART_DSR BIT(2)
106 #define RDA_UART_TX_BREAK_CONTROL BIT(3)
107 #define RDA_UART_TX_FINISH_N_WAIT BIT(4)
108 #define RDA_UART_RTS BIT(5)
109 #define RDA_UART_RX_FIFO_RESET BIT(6)
110 #define RDA_UART_TX_FIFO_RESET BIT(7)
111
112 #define RDA_UART_TX_FIFO_SIZE 16
113
114 static struct uart_driver rda_uart_driver;
115
116 struct rda_uart_port {
117 struct uart_port port;
118 struct clk *clk;
119 };
120
121 #define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
122
123 static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
124
rda_uart_write(struct uart_port * port,u32 val,unsigned int off)125 static inline void rda_uart_write(struct uart_port *port, u32 val,
126 unsigned int off)
127 {
128 writel(val, port->membase + off);
129 }
130
rda_uart_read(struct uart_port * port,unsigned int off)131 static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
132 {
133 return readl(port->membase + off);
134 }
135
rda_uart_tx_empty(struct uart_port * port)136 static unsigned int rda_uart_tx_empty(struct uart_port *port)
137 {
138 unsigned long flags;
139 unsigned int ret;
140 u32 val;
141
142 spin_lock_irqsave(&port->lock, flags);
143
144 val = rda_uart_read(port, RDA_UART_STATUS);
145 ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
146
147 spin_unlock_irqrestore(&port->lock, flags);
148
149 return ret;
150 }
151
rda_uart_get_mctrl(struct uart_port * port)152 static unsigned int rda_uart_get_mctrl(struct uart_port *port)
153 {
154 unsigned int mctrl = 0;
155 u32 cmd_set, status;
156
157 cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
158 status = rda_uart_read(port, RDA_UART_STATUS);
159 if (cmd_set & RDA_UART_RTS)
160 mctrl |= TIOCM_RTS;
161 if (!(status & RDA_UART_CTS))
162 mctrl |= TIOCM_CTS;
163
164 return mctrl;
165 }
166
rda_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)167 static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
168 {
169 u32 val;
170
171 if (mctrl & TIOCM_RTS) {
172 val = rda_uart_read(port, RDA_UART_CMD_SET);
173 rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
174 } else {
175 /* Clear RTS to stop to receive. */
176 val = rda_uart_read(port, RDA_UART_CMD_CLR);
177 rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
178 }
179
180 val = rda_uart_read(port, RDA_UART_CTRL);
181
182 if (mctrl & TIOCM_LOOP)
183 val |= RDA_UART_LOOP_BACK_EN;
184 else
185 val &= ~RDA_UART_LOOP_BACK_EN;
186
187 rda_uart_write(port, val, RDA_UART_CTRL);
188 }
189
rda_uart_stop_tx(struct uart_port * port)190 static void rda_uart_stop_tx(struct uart_port *port)
191 {
192 u32 val;
193
194 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
195 val &= ~RDA_UART_TX_DATA_NEEDED;
196 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
197
198 val = rda_uart_read(port, RDA_UART_CMD_SET);
199 val |= RDA_UART_TX_FIFO_RESET;
200 rda_uart_write(port, val, RDA_UART_CMD_SET);
201 }
202
rda_uart_stop_rx(struct uart_port * port)203 static void rda_uart_stop_rx(struct uart_port *port)
204 {
205 u32 val;
206
207 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
208 val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
209 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
210
211 /* Read Rx buffer before reset to avoid Rx timeout interrupt */
212 val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
213
214 val = rda_uart_read(port, RDA_UART_CMD_SET);
215 val |= RDA_UART_RX_FIFO_RESET;
216 rda_uart_write(port, val, RDA_UART_CMD_SET);
217 }
218
rda_uart_start_tx(struct uart_port * port)219 static void rda_uart_start_tx(struct uart_port *port)
220 {
221 u32 val;
222
223 if (uart_tx_stopped(port)) {
224 rda_uart_stop_tx(port);
225 return;
226 }
227
228 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
229 val |= RDA_UART_TX_DATA_NEEDED;
230 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
231 }
232
rda_uart_change_baudrate(struct rda_uart_port * rda_port,unsigned long baud)233 static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
234 unsigned long baud)
235 {
236 clk_set_rate(rda_port->clk, baud * 8);
237 }
238
rda_uart_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)239 static void rda_uart_set_termios(struct uart_port *port,
240 struct ktermios *termios,
241 struct ktermios *old)
242 {
243 struct rda_uart_port *rda_port = to_rda_uart_port(port);
244 unsigned long flags;
245 unsigned int ctrl, cmd_set, cmd_clr, triggers;
246 unsigned int baud;
247 u32 irq_mask;
248
249 spin_lock_irqsave(&port->lock, flags);
250
251 baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
252 rda_uart_change_baudrate(rda_port, baud);
253
254 ctrl = rda_uart_read(port, RDA_UART_CTRL);
255 cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
256 cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
257
258 switch (termios->c_cflag & CSIZE) {
259 case CS5:
260 case CS6:
261 dev_warn(port->dev, "bit size not supported, using 7 bits\n");
262 fallthrough;
263 case CS7:
264 ctrl &= ~RDA_UART_DBITS_8;
265 termios->c_cflag &= ~CSIZE;
266 termios->c_cflag |= CS7;
267 break;
268 default:
269 ctrl |= RDA_UART_DBITS_8;
270 break;
271 }
272
273 /* stop bits */
274 if (termios->c_cflag & CSTOPB)
275 ctrl |= RDA_UART_TX_SBITS_2;
276 else
277 ctrl &= ~RDA_UART_TX_SBITS_2;
278
279 /* parity check */
280 if (termios->c_cflag & PARENB) {
281 ctrl |= RDA_UART_PARITY_EN;
282
283 /* Mark or Space parity */
284 if (termios->c_cflag & CMSPAR) {
285 if (termios->c_cflag & PARODD)
286 ctrl |= RDA_UART_PARITY_MARK;
287 else
288 ctrl |= RDA_UART_PARITY_SPACE;
289 } else if (termios->c_cflag & PARODD) {
290 ctrl |= RDA_UART_PARITY_ODD;
291 } else {
292 ctrl |= RDA_UART_PARITY_EVEN;
293 }
294 } else {
295 ctrl &= ~RDA_UART_PARITY_EN;
296 }
297
298 /* Hardware handshake (RTS/CTS) */
299 if (termios->c_cflag & CRTSCTS) {
300 ctrl |= RDA_UART_FLOW_CNT_EN;
301 cmd_set |= RDA_UART_RTS;
302 } else {
303 ctrl &= ~RDA_UART_FLOW_CNT_EN;
304 cmd_clr |= RDA_UART_RTS;
305 }
306
307 ctrl |= RDA_UART_ENABLE;
308 ctrl &= ~RDA_UART_DMA_EN;
309
310 triggers = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
311 irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
312 rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
313
314 rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
315 rda_uart_write(port, ctrl, RDA_UART_CTRL);
316 rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
317 rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
318
319 rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
320
321 /* Don't rewrite B0 */
322 if (tty_termios_baud_rate(termios))
323 tty_termios_encode_baud_rate(termios, baud, baud);
324
325 /* update the per-port timeout */
326 uart_update_timeout(port, termios->c_cflag, baud);
327
328 spin_unlock_irqrestore(&port->lock, flags);
329 }
330
rda_uart_send_chars(struct uart_port * port)331 static void rda_uart_send_chars(struct uart_port *port)
332 {
333 struct circ_buf *xmit = &port->state->xmit;
334 unsigned int ch;
335 u32 val;
336
337 if (uart_tx_stopped(port))
338 return;
339
340 if (port->x_char) {
341 while (!(rda_uart_read(port, RDA_UART_STATUS) &
342 RDA_UART_TX_FIFO_MASK))
343 cpu_relax();
344
345 rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
346 port->icount.tx++;
347 port->x_char = 0;
348 }
349
350 while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
351 if (uart_circ_empty(xmit))
352 break;
353
354 ch = xmit->buf[xmit->tail];
355 rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
356 xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
357 port->icount.tx++;
358 }
359
360 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
361 uart_write_wakeup(port);
362
363 if (!uart_circ_empty(xmit)) {
364 /* Re-enable Tx FIFO interrupt */
365 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
366 val |= RDA_UART_TX_DATA_NEEDED;
367 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
368 }
369 }
370
rda_uart_receive_chars(struct uart_port * port)371 static void rda_uart_receive_chars(struct uart_port *port)
372 {
373 u32 status, val;
374
375 status = rda_uart_read(port, RDA_UART_STATUS);
376 while ((status & RDA_UART_RX_FIFO_MASK)) {
377 char flag = TTY_NORMAL;
378
379 if (status & RDA_UART_RX_PARITY_ERR) {
380 port->icount.parity++;
381 flag = TTY_PARITY;
382 }
383
384 if (status & RDA_UART_RX_FRAMING_ERR) {
385 port->icount.frame++;
386 flag = TTY_FRAME;
387 }
388
389 if (status & RDA_UART_RX_OVERFLOW_ERR) {
390 port->icount.overrun++;
391 flag = TTY_OVERRUN;
392 }
393
394 val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
395 val &= 0xff;
396
397 port->icount.rx++;
398 tty_insert_flip_char(&port->state->port, val, flag);
399
400 status = rda_uart_read(port, RDA_UART_STATUS);
401 }
402
403 tty_flip_buffer_push(&port->state->port);
404 }
405
rda_interrupt(int irq,void * dev_id)406 static irqreturn_t rda_interrupt(int irq, void *dev_id)
407 {
408 struct uart_port *port = dev_id;
409 unsigned long flags;
410 u32 val, irq_mask;
411
412 spin_lock_irqsave(&port->lock, flags);
413
414 /* Clear IRQ cause */
415 val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
416 rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
417
418 if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
419 rda_uart_receive_chars(port);
420
421 if (val & (RDA_UART_TX_DATA_NEEDED)) {
422 irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
423 irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
424 rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
425
426 rda_uart_send_chars(port);
427 }
428
429 spin_unlock_irqrestore(&port->lock, flags);
430
431 return IRQ_HANDLED;
432 }
433
rda_uart_startup(struct uart_port * port)434 static int rda_uart_startup(struct uart_port *port)
435 {
436 unsigned long flags;
437 int ret;
438 u32 val;
439
440 spin_lock_irqsave(&port->lock, flags);
441 rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
442 spin_unlock_irqrestore(&port->lock, flags);
443
444 ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
445 "rda-uart", port);
446 if (ret)
447 return ret;
448
449 spin_lock_irqsave(&port->lock, flags);
450
451 val = rda_uart_read(port, RDA_UART_CTRL);
452 val |= RDA_UART_ENABLE;
453 rda_uart_write(port, val, RDA_UART_CTRL);
454
455 /* enable rx interrupt */
456 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
457 val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
458 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
459
460 spin_unlock_irqrestore(&port->lock, flags);
461
462 return 0;
463 }
464
rda_uart_shutdown(struct uart_port * port)465 static void rda_uart_shutdown(struct uart_port *port)
466 {
467 unsigned long flags;
468 u32 val;
469
470 spin_lock_irqsave(&port->lock, flags);
471
472 rda_uart_stop_tx(port);
473 rda_uart_stop_rx(port);
474
475 val = rda_uart_read(port, RDA_UART_CTRL);
476 val &= ~RDA_UART_ENABLE;
477 rda_uart_write(port, val, RDA_UART_CTRL);
478
479 spin_unlock_irqrestore(&port->lock, flags);
480 }
481
rda_uart_type(struct uart_port * port)482 static const char *rda_uart_type(struct uart_port *port)
483 {
484 return (port->type == PORT_RDA) ? "rda-uart" : NULL;
485 }
486
rda_uart_request_port(struct uart_port * port)487 static int rda_uart_request_port(struct uart_port *port)
488 {
489 struct platform_device *pdev = to_platform_device(port->dev);
490 struct resource *res;
491
492 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
493 if (!res)
494 return -ENXIO;
495
496 if (!devm_request_mem_region(port->dev, port->mapbase,
497 resource_size(res), dev_name(port->dev)))
498 return -EBUSY;
499
500 if (port->flags & UPF_IOREMAP) {
501 port->membase = devm_ioremap(port->dev, port->mapbase,
502 resource_size(res));
503 if (!port->membase)
504 return -EBUSY;
505 }
506
507 return 0;
508 }
509
rda_uart_config_port(struct uart_port * port,int flags)510 static void rda_uart_config_port(struct uart_port *port, int flags)
511 {
512 unsigned long irq_flags;
513
514 if (flags & UART_CONFIG_TYPE) {
515 port->type = PORT_RDA;
516 rda_uart_request_port(port);
517 }
518
519 spin_lock_irqsave(&port->lock, irq_flags);
520
521 /* Clear mask, so no surprise interrupts. */
522 rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
523
524 /* Clear status register */
525 rda_uart_write(port, 0, RDA_UART_STATUS);
526
527 spin_unlock_irqrestore(&port->lock, irq_flags);
528 }
529
rda_uart_release_port(struct uart_port * port)530 static void rda_uart_release_port(struct uart_port *port)
531 {
532 struct platform_device *pdev = to_platform_device(port->dev);
533 struct resource *res;
534
535 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
536 if (!res)
537 return;
538
539 if (port->flags & UPF_IOREMAP) {
540 devm_release_mem_region(port->dev, port->mapbase,
541 resource_size(res));
542 devm_iounmap(port->dev, port->membase);
543 port->membase = NULL;
544 }
545 }
546
rda_uart_verify_port(struct uart_port * port,struct serial_struct * ser)547 static int rda_uart_verify_port(struct uart_port *port,
548 struct serial_struct *ser)
549 {
550 if (port->type != PORT_RDA)
551 return -EINVAL;
552
553 if (port->irq != ser->irq)
554 return -EINVAL;
555
556 return 0;
557 }
558
559 static const struct uart_ops rda_uart_ops = {
560 .tx_empty = rda_uart_tx_empty,
561 .get_mctrl = rda_uart_get_mctrl,
562 .set_mctrl = rda_uart_set_mctrl,
563 .start_tx = rda_uart_start_tx,
564 .stop_tx = rda_uart_stop_tx,
565 .stop_rx = rda_uart_stop_rx,
566 .startup = rda_uart_startup,
567 .shutdown = rda_uart_shutdown,
568 .set_termios = rda_uart_set_termios,
569 .type = rda_uart_type,
570 .request_port = rda_uart_request_port,
571 .release_port = rda_uart_release_port,
572 .config_port = rda_uart_config_port,
573 .verify_port = rda_uart_verify_port,
574 };
575
576 #ifdef CONFIG_SERIAL_RDA_CONSOLE
577
rda_console_putchar(struct uart_port * port,unsigned char ch)578 static void rda_console_putchar(struct uart_port *port, unsigned char ch)
579 {
580 if (!port->membase)
581 return;
582
583 while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
584 cpu_relax();
585
586 rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
587 }
588
rda_uart_port_write(struct uart_port * port,const char * s,u_int count)589 static void rda_uart_port_write(struct uart_port *port, const char *s,
590 u_int count)
591 {
592 u32 old_irq_mask;
593 unsigned long flags;
594 int locked;
595
596 local_irq_save(flags);
597
598 if (port->sysrq) {
599 locked = 0;
600 } else if (oops_in_progress) {
601 locked = spin_trylock(&port->lock);
602 } else {
603 spin_lock(&port->lock);
604 locked = 1;
605 }
606
607 old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
608 rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
609
610 uart_console_write(port, s, count, rda_console_putchar);
611
612 /* wait until all contents have been sent out */
613 while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
614 cpu_relax();
615
616 rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
617
618 if (locked)
619 spin_unlock(&port->lock);
620
621 local_irq_restore(flags);
622 }
623
rda_uart_console_write(struct console * co,const char * s,u_int count)624 static void rda_uart_console_write(struct console *co, const char *s,
625 u_int count)
626 {
627 struct rda_uart_port *rda_port;
628
629 rda_port = rda_uart_ports[co->index];
630 if (!rda_port)
631 return;
632
633 rda_uart_port_write(&rda_port->port, s, count);
634 }
635
rda_uart_console_setup(struct console * co,char * options)636 static int rda_uart_console_setup(struct console *co, char *options)
637 {
638 struct rda_uart_port *rda_port;
639 int baud = 921600;
640 int bits = 8;
641 int parity = 'n';
642 int flow = 'n';
643
644 if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
645 return -EINVAL;
646
647 rda_port = rda_uart_ports[co->index];
648 if (!rda_port || !rda_port->port.membase)
649 return -ENODEV;
650
651 if (options)
652 uart_parse_options(options, &baud, &parity, &bits, &flow);
653
654 return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
655 }
656
657 static struct console rda_uart_console = {
658 .name = RDA_UART_DEV_NAME,
659 .write = rda_uart_console_write,
660 .device = uart_console_device,
661 .setup = rda_uart_console_setup,
662 .flags = CON_PRINTBUFFER,
663 .index = -1,
664 .data = &rda_uart_driver,
665 };
666
rda_uart_console_init(void)667 static int __init rda_uart_console_init(void)
668 {
669 register_console(&rda_uart_console);
670
671 return 0;
672 }
673 console_initcall(rda_uart_console_init);
674
rda_uart_early_console_write(struct console * co,const char * s,u_int count)675 static void rda_uart_early_console_write(struct console *co,
676 const char *s,
677 u_int count)
678 {
679 struct earlycon_device *dev = co->data;
680
681 rda_uart_port_write(&dev->port, s, count);
682 }
683
684 static int __init
rda_uart_early_console_setup(struct earlycon_device * device,const char * opt)685 rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
686 {
687 if (!device->port.membase)
688 return -ENODEV;
689
690 device->con->write = rda_uart_early_console_write;
691
692 return 0;
693 }
694
695 OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
696 rda_uart_early_console_setup);
697
698 #define RDA_UART_CONSOLE (&rda_uart_console)
699 #else
700 #define RDA_UART_CONSOLE NULL
701 #endif /* CONFIG_SERIAL_RDA_CONSOLE */
702
703 static struct uart_driver rda_uart_driver = {
704 .owner = THIS_MODULE,
705 .driver_name = "rda-uart",
706 .dev_name = RDA_UART_DEV_NAME,
707 .nr = RDA_UART_PORT_NUM,
708 .cons = RDA_UART_CONSOLE,
709 };
710
711 static const struct of_device_id rda_uart_dt_matches[] = {
712 { .compatible = "rda,8810pl-uart" },
713 { }
714 };
715 MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
716
rda_uart_probe(struct platform_device * pdev)717 static int rda_uart_probe(struct platform_device *pdev)
718 {
719 struct resource *res_mem;
720 struct rda_uart_port *rda_port;
721 int ret, irq;
722
723 if (pdev->dev.of_node)
724 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
725
726 if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
727 dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
728 return -EINVAL;
729 }
730
731 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
732 if (!res_mem) {
733 dev_err(&pdev->dev, "could not get mem\n");
734 return -ENODEV;
735 }
736
737 irq = platform_get_irq(pdev, 0);
738 if (irq < 0)
739 return irq;
740
741 if (rda_uart_ports[pdev->id]) {
742 dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
743 return -EBUSY;
744 }
745
746 rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
747 if (!rda_port)
748 return -ENOMEM;
749
750 rda_port->clk = devm_clk_get(&pdev->dev, NULL);
751 if (IS_ERR(rda_port->clk)) {
752 dev_err(&pdev->dev, "could not get clk\n");
753 return PTR_ERR(rda_port->clk);
754 }
755
756 rda_port->port.dev = &pdev->dev;
757 rda_port->port.regshift = 0;
758 rda_port->port.line = pdev->id;
759 rda_port->port.type = PORT_RDA;
760 rda_port->port.iotype = UPIO_MEM;
761 rda_port->port.mapbase = res_mem->start;
762 rda_port->port.irq = irq;
763 rda_port->port.uartclk = clk_get_rate(rda_port->clk);
764 if (rda_port->port.uartclk == 0) {
765 dev_err(&pdev->dev, "clock rate is zero\n");
766 return -EINVAL;
767 }
768 rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
769 UPF_LOW_LATENCY;
770 rda_port->port.x_char = 0;
771 rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
772 rda_port->port.ops = &rda_uart_ops;
773
774 rda_uart_ports[pdev->id] = rda_port;
775 platform_set_drvdata(pdev, rda_port);
776
777 ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
778 if (ret)
779 rda_uart_ports[pdev->id] = NULL;
780
781 return ret;
782 }
783
rda_uart_remove(struct platform_device * pdev)784 static int rda_uart_remove(struct platform_device *pdev)
785 {
786 struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
787
788 uart_remove_one_port(&rda_uart_driver, &rda_port->port);
789 rda_uart_ports[pdev->id] = NULL;
790
791 return 0;
792 }
793
794 static struct platform_driver rda_uart_platform_driver = {
795 .probe = rda_uart_probe,
796 .remove = rda_uart_remove,
797 .driver = {
798 .name = "rda-uart",
799 .of_match_table = rda_uart_dt_matches,
800 },
801 };
802
rda_uart_init(void)803 static int __init rda_uart_init(void)
804 {
805 int ret;
806
807 ret = uart_register_driver(&rda_uart_driver);
808 if (ret)
809 return ret;
810
811 ret = platform_driver_register(&rda_uart_platform_driver);
812 if (ret)
813 uart_unregister_driver(&rda_uart_driver);
814
815 return ret;
816 }
817
rda_uart_exit(void)818 static void __exit rda_uart_exit(void)
819 {
820 platform_driver_unregister(&rda_uart_platform_driver);
821 uart_unregister_driver(&rda_uart_driver);
822 }
823
824 module_init(rda_uart_init);
825 module_exit(rda_uart_exit);
826
827 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
828 MODULE_DESCRIPTION("RDA8810PL serial device driver");
829 MODULE_LICENSE("GPL");
830