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11#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
12#define SUPPORT_SYSRQ
13#endif
14
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/console.h>
18#include <linux/serial_core.h>
19#include <linux/serial.h>
20#include <linux/clk.h>
21#include <linux/io.h>
22#include <linux/tty.h>
23#include <linux/tty_flip.h>
24#include <linux/ioport.h>
25#include <linux/of.h>
26#include <linux/platform_device.h>
27#include <linux/regmap.h>
28
29#include <linux/mfd/syscon.h>
30#include <linux/mfd/syscon/clps711x.h>
31
32#include "serial_mctrl_gpio.h"
33
34#define UART_CLPS711X_DEVNAME "ttyCL"
35#define UART_CLPS711X_NR 2
36#define UART_CLPS711X_MAJOR 204
37#define UART_CLPS711X_MINOR 40
38
39#define UARTDR_OFFSET (0x00)
40#define UBRLCR_OFFSET (0x40)
41
42#define UARTDR_FRMERR (1 << 8)
43#define UARTDR_PARERR (1 << 9)
44#define UARTDR_OVERR (1 << 10)
45
46#define UBRLCR_BAUD_MASK ((1 << 12) - 1)
47#define UBRLCR_BREAK (1 << 12)
48#define UBRLCR_PRTEN (1 << 13)
49#define UBRLCR_EVENPRT (1 << 14)
50#define UBRLCR_XSTOP (1 << 15)
51#define UBRLCR_FIFOEN (1 << 16)
52#define UBRLCR_WRDLEN5 (0 << 17)
53#define UBRLCR_WRDLEN6 (1 << 17)
54#define UBRLCR_WRDLEN7 (2 << 17)
55#define UBRLCR_WRDLEN8 (3 << 17)
56#define UBRLCR_WRDLEN_MASK (3 << 17)
57
58struct clps711x_port {
59 struct uart_port port;
60 unsigned int tx_enabled;
61 int rx_irq;
62 struct regmap *syscon;
63 struct mctrl_gpios *gpios;
64};
65
66static struct uart_driver clps711x_uart = {
67 .owner = THIS_MODULE,
68 .driver_name = UART_CLPS711X_DEVNAME,
69 .dev_name = UART_CLPS711X_DEVNAME,
70 .major = UART_CLPS711X_MAJOR,
71 .minor = UART_CLPS711X_MINOR,
72 .nr = UART_CLPS711X_NR,
73};
74
75static void uart_clps711x_stop_tx(struct uart_port *port)
76{
77 struct clps711x_port *s = dev_get_drvdata(port->dev);
78
79 if (s->tx_enabled) {
80 disable_irq(port->irq);
81 s->tx_enabled = 0;
82 }
83}
84
85static void uart_clps711x_start_tx(struct uart_port *port)
86{
87 struct clps711x_port *s = dev_get_drvdata(port->dev);
88
89 if (!s->tx_enabled) {
90 s->tx_enabled = 1;
91 enable_irq(port->irq);
92 }
93}
94
95static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
96{
97 struct uart_port *port = dev_id;
98 struct clps711x_port *s = dev_get_drvdata(port->dev);
99 unsigned int status, flg;
100 u16 ch;
101
102 for (;;) {
103 u32 sysflg = 0;
104
105 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
106 if (sysflg & SYSFLG_URXFE)
107 break;
108
109 ch = readw(port->membase + UARTDR_OFFSET);
110 status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
111 ch &= 0xff;
112
113 port->icount.rx++;
114 flg = TTY_NORMAL;
115
116 if (unlikely(status)) {
117 if (status & UARTDR_PARERR)
118 port->icount.parity++;
119 else if (status & UARTDR_FRMERR)
120 port->icount.frame++;
121 else if (status & UARTDR_OVERR)
122 port->icount.overrun++;
123
124 status &= port->read_status_mask;
125
126 if (status & UARTDR_PARERR)
127 flg = TTY_PARITY;
128 else if (status & UARTDR_FRMERR)
129 flg = TTY_FRAME;
130 else if (status & UARTDR_OVERR)
131 flg = TTY_OVERRUN;
132 }
133
134 if (uart_handle_sysrq_char(port, ch))
135 continue;
136
137 if (status & port->ignore_status_mask)
138 continue;
139
140 uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
141 }
142
143 tty_flip_buffer_push(&port->state->port);
144
145 return IRQ_HANDLED;
146}
147
148static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
149{
150 struct uart_port *port = dev_id;
151 struct clps711x_port *s = dev_get_drvdata(port->dev);
152 struct circ_buf *xmit = &port->state->xmit;
153
154 if (port->x_char) {
155 writew(port->x_char, port->membase + UARTDR_OFFSET);
156 port->icount.tx++;
157 port->x_char = 0;
158 return IRQ_HANDLED;
159 }
160
161 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
162 if (s->tx_enabled) {
163 disable_irq_nosync(port->irq);
164 s->tx_enabled = 0;
165 }
166 return IRQ_HANDLED;
167 }
168
169 while (!uart_circ_empty(xmit)) {
170 u32 sysflg = 0;
171
172 writew(xmit->buf[xmit->tail], port->membase + UARTDR_OFFSET);
173 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
174 port->icount.tx++;
175
176 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
177 if (sysflg & SYSFLG_UTXFF)
178 break;
179 }
180
181 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
182 uart_write_wakeup(port);
183
184 return IRQ_HANDLED;
185}
186
187static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
188{
189 struct clps711x_port *s = dev_get_drvdata(port->dev);
190 u32 sysflg = 0;
191
192 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
193
194 return (sysflg & SYSFLG_UBUSY) ? 0 : TIOCSER_TEMT;
195}
196
197static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
198{
199 unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
200 struct clps711x_port *s = dev_get_drvdata(port->dev);
201
202 return mctrl_gpio_get(s->gpios, &result);
203}
204
205static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
206{
207 struct clps711x_port *s = dev_get_drvdata(port->dev);
208
209 mctrl_gpio_set(s->gpios, mctrl);
210}
211
212static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
213{
214 unsigned int ubrlcr;
215
216 ubrlcr = readl(port->membase + UBRLCR_OFFSET);
217 if (break_state)
218 ubrlcr |= UBRLCR_BREAK;
219 else
220 ubrlcr &= ~UBRLCR_BREAK;
221 writel(ubrlcr, port->membase + UBRLCR_OFFSET);
222}
223
224static void uart_clps711x_set_ldisc(struct uart_port *port,
225 struct ktermios *termios)
226{
227 if (!port->line) {
228 struct clps711x_port *s = dev_get_drvdata(port->dev);
229
230 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON1_SIREN,
231 (termios->c_line == N_IRDA) ? SYSCON1_SIREN : 0);
232 }
233}
234
235static int uart_clps711x_startup(struct uart_port *port)
236{
237 struct clps711x_port *s = dev_get_drvdata(port->dev);
238
239
240 writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
241 port->membase + UBRLCR_OFFSET);
242
243
244 return regmap_update_bits(s->syscon, SYSCON_OFFSET,
245 SYSCON_UARTEN, SYSCON_UARTEN);
246}
247
248static void uart_clps711x_shutdown(struct uart_port *port)
249{
250 struct clps711x_port *s = dev_get_drvdata(port->dev);
251
252
253 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
254}
255
256static void uart_clps711x_set_termios(struct uart_port *port,
257 struct ktermios *termios,
258 struct ktermios *old)
259{
260 u32 ubrlcr;
261 unsigned int baud, quot;
262
263
264 termios->c_cflag &= ~CMSPAR;
265 termios->c_iflag &= ~(BRKINT | IGNBRK);
266
267
268 baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
269 port->uartclk / 16);
270 quot = uart_get_divisor(port, baud);
271
272 switch (termios->c_cflag & CSIZE) {
273 case CS5:
274 ubrlcr = UBRLCR_WRDLEN5;
275 break;
276 case CS6:
277 ubrlcr = UBRLCR_WRDLEN6;
278 break;
279 case CS7:
280 ubrlcr = UBRLCR_WRDLEN7;
281 break;
282 case CS8:
283 default:
284 ubrlcr = UBRLCR_WRDLEN8;
285 break;
286 }
287
288 if (termios->c_cflag & CSTOPB)
289 ubrlcr |= UBRLCR_XSTOP;
290
291 if (termios->c_cflag & PARENB) {
292 ubrlcr |= UBRLCR_PRTEN;
293 if (!(termios->c_cflag & PARODD))
294 ubrlcr |= UBRLCR_EVENPRT;
295 }
296
297
298 ubrlcr |= UBRLCR_FIFOEN;
299
300
301 port->read_status_mask = UARTDR_OVERR;
302 if (termios->c_iflag & INPCK)
303 port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
304
305
306 port->ignore_status_mask = 0;
307 if (!(termios->c_cflag & CREAD))
308 port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
309 UARTDR_FRMERR;
310
311 uart_update_timeout(port, termios->c_cflag, baud);
312
313 writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
314}
315
316static const char *uart_clps711x_type(struct uart_port *port)
317{
318 return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
319}
320
321static void uart_clps711x_config_port(struct uart_port *port, int flags)
322{
323 if (flags & UART_CONFIG_TYPE)
324 port->type = PORT_CLPS711X;
325}
326
327static void uart_clps711x_nop_void(struct uart_port *port)
328{
329}
330
331static int uart_clps711x_nop_int(struct uart_port *port)
332{
333 return 0;
334}
335
336static const struct uart_ops uart_clps711x_ops = {
337 .tx_empty = uart_clps711x_tx_empty,
338 .set_mctrl = uart_clps711x_set_mctrl,
339 .get_mctrl = uart_clps711x_get_mctrl,
340 .stop_tx = uart_clps711x_stop_tx,
341 .start_tx = uart_clps711x_start_tx,
342 .stop_rx = uart_clps711x_nop_void,
343 .break_ctl = uart_clps711x_break_ctl,
344 .set_ldisc = uart_clps711x_set_ldisc,
345 .startup = uart_clps711x_startup,
346 .shutdown = uart_clps711x_shutdown,
347 .set_termios = uart_clps711x_set_termios,
348 .type = uart_clps711x_type,
349 .config_port = uart_clps711x_config_port,
350 .release_port = uart_clps711x_nop_void,
351 .request_port = uart_clps711x_nop_int,
352};
353
354#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
355static void uart_clps711x_console_putchar(struct uart_port *port, int ch)
356{
357 struct clps711x_port *s = dev_get_drvdata(port->dev);
358 u32 sysflg = 0;
359
360
361 do {
362 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
363 } while (sysflg & SYSFLG_UTXFF);
364
365 writew(ch, port->membase + UARTDR_OFFSET);
366}
367
368static void uart_clps711x_console_write(struct console *co, const char *c,
369 unsigned n)
370{
371 struct uart_port *port = clps711x_uart.state[co->index].uart_port;
372 struct clps711x_port *s = dev_get_drvdata(port->dev);
373 u32 sysflg = 0;
374
375 uart_console_write(port, c, n, uart_clps711x_console_putchar);
376
377
378 do {
379 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
380 } while (sysflg & SYSFLG_UBUSY);
381}
382
383static int uart_clps711x_console_setup(struct console *co, char *options)
384{
385 int baud = 38400, bits = 8, parity = 'n', flow = 'n';
386 int ret, index = co->index;
387 struct clps711x_port *s;
388 struct uart_port *port;
389 unsigned int quot;
390 u32 ubrlcr;
391
392 if (index < 0 || index >= UART_CLPS711X_NR)
393 return -EINVAL;
394
395 port = clps711x_uart.state[index].uart_port;
396 if (!port)
397 return -ENODEV;
398
399 s = dev_get_drvdata(port->dev);
400
401 if (!options) {
402 u32 syscon = 0;
403
404 regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
405 if (syscon & SYSCON_UARTEN) {
406 ubrlcr = readl(port->membase + UBRLCR_OFFSET);
407
408 if (ubrlcr & UBRLCR_PRTEN) {
409 if (ubrlcr & UBRLCR_EVENPRT)
410 parity = 'e';
411 else
412 parity = 'o';
413 }
414
415 if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
416 bits = 7;
417
418 quot = ubrlcr & UBRLCR_BAUD_MASK;
419 baud = port->uartclk / (16 * (quot + 1));
420 }
421 } else
422 uart_parse_options(options, &baud, &parity, &bits, &flow);
423
424 ret = uart_set_options(port, co, baud, parity, bits, flow);
425 if (ret)
426 return ret;
427
428 return regmap_update_bits(s->syscon, SYSCON_OFFSET,
429 SYSCON_UARTEN, SYSCON_UARTEN);
430}
431
432static struct console clps711x_console = {
433 .name = UART_CLPS711X_DEVNAME,
434 .device = uart_console_device,
435 .write = uart_clps711x_console_write,
436 .setup = uart_clps711x_console_setup,
437 .flags = CON_PRINTBUFFER,
438 .index = -1,
439};
440#endif
441
442static int uart_clps711x_probe(struct platform_device *pdev)
443{
444 struct device_node *np = pdev->dev.of_node;
445 int ret, index = np ? of_alias_get_id(np, "serial") : pdev->id;
446 struct clps711x_port *s;
447 struct resource *res;
448 struct clk *uart_clk;
449 int irq;
450
451 if (index < 0 || index >= UART_CLPS711X_NR)
452 return -EINVAL;
453
454 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
455 if (!s)
456 return -ENOMEM;
457
458 uart_clk = devm_clk_get(&pdev->dev, NULL);
459 if (IS_ERR(uart_clk))
460 return PTR_ERR(uart_clk);
461
462 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
463 s->port.membase = devm_ioremap_resource(&pdev->dev, res);
464 if (IS_ERR(s->port.membase))
465 return PTR_ERR(s->port.membase);
466
467 irq = platform_get_irq(pdev, 0);
468 if (irq < 0)
469 return irq;
470 s->port.irq = irq;
471
472 s->rx_irq = platform_get_irq(pdev, 1);
473 if (s->rx_irq < 0)
474 return s->rx_irq;
475
476 if (!np) {
477 char syscon_name[9];
478
479 sprintf(syscon_name, "syscon.%i", index + 1);
480 s->syscon = syscon_regmap_lookup_by_pdevname(syscon_name);
481 if (IS_ERR(s->syscon))
482 return PTR_ERR(s->syscon);
483 } else {
484 s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
485 if (IS_ERR(s->syscon))
486 return PTR_ERR(s->syscon);
487 }
488
489 s->port.line = index;
490 s->port.dev = &pdev->dev;
491 s->port.iotype = UPIO_MEM32;
492 s->port.mapbase = res->start;
493 s->port.type = PORT_CLPS711X;
494 s->port.fifosize = 16;
495 s->port.flags = UPF_SKIP_TEST | UPF_FIXED_TYPE;
496 s->port.uartclk = clk_get_rate(uart_clk);
497 s->port.ops = &uart_clps711x_ops;
498
499 platform_set_drvdata(pdev, s);
500
501 s->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
502 if (IS_ERR(s->gpios))
503 return PTR_ERR(s->gpios);
504
505 ret = uart_add_one_port(&clps711x_uart, &s->port);
506 if (ret)
507 return ret;
508
509
510 if (!uart_console(&s->port))
511 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
512
513 s->tx_enabled = 1;
514
515 ret = devm_request_irq(&pdev->dev, s->port.irq, uart_clps711x_int_tx, 0,
516 dev_name(&pdev->dev), &s->port);
517 if (ret) {
518 uart_remove_one_port(&clps711x_uart, &s->port);
519 return ret;
520 }
521
522 ret = devm_request_irq(&pdev->dev, s->rx_irq, uart_clps711x_int_rx, 0,
523 dev_name(&pdev->dev), &s->port);
524 if (ret)
525 uart_remove_one_port(&clps711x_uart, &s->port);
526
527 return ret;
528}
529
530static int uart_clps711x_remove(struct platform_device *pdev)
531{
532 struct clps711x_port *s = platform_get_drvdata(pdev);
533
534 return uart_remove_one_port(&clps711x_uart, &s->port);
535}
536
537static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
538 { .compatible = "cirrus,ep7209-uart", },
539 { }
540};
541MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);
542
543static struct platform_driver clps711x_uart_platform = {
544 .driver = {
545 .name = "clps711x-uart",
546 .of_match_table = of_match_ptr(clps711x_uart_dt_ids),
547 },
548 .probe = uart_clps711x_probe,
549 .remove = uart_clps711x_remove,
550};
551
552static int __init uart_clps711x_init(void)
553{
554 int ret;
555
556#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
557 clps711x_uart.cons = &clps711x_console;
558 clps711x_console.data = &clps711x_uart;
559#endif
560
561 ret = uart_register_driver(&clps711x_uart);
562 if (ret)
563 return ret;
564
565 return platform_driver_register(&clps711x_uart_platform);
566}
567module_init(uart_clps711x_init);
568
569static void __exit uart_clps711x_exit(void)
570{
571 platform_driver_unregister(&clps711x_uart_platform);
572 uart_unregister_driver(&clps711x_uart);
573}
574module_exit(uart_clps711x_exit);
575
576MODULE_AUTHOR("Deep Blue Solutions Ltd");
577MODULE_DESCRIPTION("CLPS711X serial driver");
578MODULE_LICENSE("GPL");
579
