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15#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
16#define SUPPORT_SYSRQ
17#endif
18
19#include <linux/module.h>
20#include <linux/device.h>
21#include <linux/console.h>
22#include <linux/serial_core.h>
23#include <linux/serial.h>
24#include <linux/clk.h>
25#include <linux/io.h>
26#include <linux/tty.h>
27#include <linux/tty_flip.h>
28#include <linux/ioport.h>
29#include <linux/of.h>
30#include <linux/platform_device.h>
31#include <linux/regmap.h>
32
33#include <linux/mfd/syscon.h>
34#include <linux/mfd/syscon/clps711x.h>
35
36#include "serial_mctrl_gpio.h"
37
38#define UART_CLPS711X_DEVNAME "ttyCL"
39#define UART_CLPS711X_NR 2
40#define UART_CLPS711X_MAJOR 204
41#define UART_CLPS711X_MINOR 40
42
43#define UARTDR_OFFSET (0x00)
44#define UBRLCR_OFFSET (0x40)
45
46#define UARTDR_FRMERR (1 << 8)
47#define UARTDR_PARERR (1 << 9)
48#define UARTDR_OVERR (1 << 10)
49
50#define UBRLCR_BAUD_MASK ((1 << 12) - 1)
51#define UBRLCR_BREAK (1 << 12)
52#define UBRLCR_PRTEN (1 << 13)
53#define UBRLCR_EVENPRT (1 << 14)
54#define UBRLCR_XSTOP (1 << 15)
55#define UBRLCR_FIFOEN (1 << 16)
56#define UBRLCR_WRDLEN5 (0 << 17)
57#define UBRLCR_WRDLEN6 (1 << 17)
58#define UBRLCR_WRDLEN7 (2 << 17)
59#define UBRLCR_WRDLEN8 (3 << 17)
60#define UBRLCR_WRDLEN_MASK (3 << 17)
61
62struct clps711x_port {
63 struct uart_port port;
64 unsigned int tx_enabled;
65 int rx_irq;
66 struct regmap *syscon;
67 struct mctrl_gpios *gpios;
68};
69
70static struct uart_driver clps711x_uart = {
71 .owner = THIS_MODULE,
72 .driver_name = UART_CLPS711X_DEVNAME,
73 .dev_name = UART_CLPS711X_DEVNAME,
74 .major = UART_CLPS711X_MAJOR,
75 .minor = UART_CLPS711X_MINOR,
76 .nr = UART_CLPS711X_NR,
77};
78
79static void uart_clps711x_stop_tx(struct uart_port *port)
80{
81 struct clps711x_port *s = dev_get_drvdata(port->dev);
82
83 if (s->tx_enabled) {
84 disable_irq(port->irq);
85 s->tx_enabled = 0;
86 }
87}
88
89static void uart_clps711x_start_tx(struct uart_port *port)
90{
91 struct clps711x_port *s = dev_get_drvdata(port->dev);
92
93 if (!s->tx_enabled) {
94 s->tx_enabled = 1;
95 enable_irq(port->irq);
96 }
97}
98
99static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
100{
101 struct uart_port *port = dev_id;
102 struct clps711x_port *s = dev_get_drvdata(port->dev);
103 unsigned int status, flg;
104 u16 ch;
105
106 for (;;) {
107 u32 sysflg = 0;
108
109 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
110 if (sysflg & SYSFLG_URXFE)
111 break;
112
113 ch = readw(port->membase + UARTDR_OFFSET);
114 status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
115 ch &= 0xff;
116
117 port->icount.rx++;
118 flg = TTY_NORMAL;
119
120 if (unlikely(status)) {
121 if (status & UARTDR_PARERR)
122 port->icount.parity++;
123 else if (status & UARTDR_FRMERR)
124 port->icount.frame++;
125 else if (status & UARTDR_OVERR)
126 port->icount.overrun++;
127
128 status &= port->read_status_mask;
129
130 if (status & UARTDR_PARERR)
131 flg = TTY_PARITY;
132 else if (status & UARTDR_FRMERR)
133 flg = TTY_FRAME;
134 else if (status & UARTDR_OVERR)
135 flg = TTY_OVERRUN;
136 }
137
138 if (uart_handle_sysrq_char(port, ch))
139 continue;
140
141 if (status & port->ignore_status_mask)
142 continue;
143
144 uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
145 }
146
147 tty_flip_buffer_push(&port->state->port);
148
149 return IRQ_HANDLED;
150}
151
152static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
153{
154 struct uart_port *port = dev_id;
155 struct clps711x_port *s = dev_get_drvdata(port->dev);
156 struct circ_buf *xmit = &port->state->xmit;
157
158 if (port->x_char) {
159 writew(port->x_char, port->membase + UARTDR_OFFSET);
160 port->icount.tx++;
161 port->x_char = 0;
162 return IRQ_HANDLED;
163 }
164
165 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
166 if (s->tx_enabled) {
167 disable_irq_nosync(port->irq);
168 s->tx_enabled = 0;
169 }
170 return IRQ_HANDLED;
171 }
172
173 while (!uart_circ_empty(xmit)) {
174 u32 sysflg = 0;
175
176 writew(xmit->buf[xmit->tail], port->membase + UARTDR_OFFSET);
177 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
178 port->icount.tx++;
179
180 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
181 if (sysflg & SYSFLG_UTXFF)
182 break;
183 }
184
185 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
186 uart_write_wakeup(port);
187
188 return IRQ_HANDLED;
189}
190
191static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
192{
193 struct clps711x_port *s = dev_get_drvdata(port->dev);
194 u32 sysflg = 0;
195
196 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
197
198 return (sysflg & SYSFLG_UBUSY) ? 0 : TIOCSER_TEMT;
199}
200
201static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
202{
203 unsigned int result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
204 struct clps711x_port *s = dev_get_drvdata(port->dev);
205
206 return mctrl_gpio_get(s->gpios, &result);
207}
208
209static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
210{
211 struct clps711x_port *s = dev_get_drvdata(port->dev);
212
213 mctrl_gpio_set(s->gpios, mctrl);
214}
215
216static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
217{
218 unsigned int ubrlcr;
219
220 ubrlcr = readl(port->membase + UBRLCR_OFFSET);
221 if (break_state)
222 ubrlcr |= UBRLCR_BREAK;
223 else
224 ubrlcr &= ~UBRLCR_BREAK;
225 writel(ubrlcr, port->membase + UBRLCR_OFFSET);
226}
227
228static void uart_clps711x_set_ldisc(struct uart_port *port,
229 struct ktermios *termios)
230{
231 if (!port->line) {
232 struct clps711x_port *s = dev_get_drvdata(port->dev);
233
234 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON1_SIREN,
235 (termios->c_line == N_IRDA) ? SYSCON1_SIREN : 0);
236 }
237}
238
239static int uart_clps711x_startup(struct uart_port *port)
240{
241 struct clps711x_port *s = dev_get_drvdata(port->dev);
242
243
244 writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
245 port->membase + UBRLCR_OFFSET);
246
247
248 return regmap_update_bits(s->syscon, SYSCON_OFFSET,
249 SYSCON_UARTEN, SYSCON_UARTEN);
250}
251
252static void uart_clps711x_shutdown(struct uart_port *port)
253{
254 struct clps711x_port *s = dev_get_drvdata(port->dev);
255
256
257 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
258}
259
260static void uart_clps711x_set_termios(struct uart_port *port,
261 struct ktermios *termios,
262 struct ktermios *old)
263{
264 u32 ubrlcr;
265 unsigned int baud, quot;
266
267
268 termios->c_cflag &= ~CMSPAR;
269 termios->c_iflag &= ~(BRKINT | IGNBRK);
270
271
272 baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
273 port->uartclk / 16);
274 quot = uart_get_divisor(port, baud);
275
276 switch (termios->c_cflag & CSIZE) {
277 case CS5:
278 ubrlcr = UBRLCR_WRDLEN5;
279 break;
280 case CS6:
281 ubrlcr = UBRLCR_WRDLEN6;
282 break;
283 case CS7:
284 ubrlcr = UBRLCR_WRDLEN7;
285 break;
286 case CS8:
287 default:
288 ubrlcr = UBRLCR_WRDLEN8;
289 break;
290 }
291
292 if (termios->c_cflag & CSTOPB)
293 ubrlcr |= UBRLCR_XSTOP;
294
295 if (termios->c_cflag & PARENB) {
296 ubrlcr |= UBRLCR_PRTEN;
297 if (!(termios->c_cflag & PARODD))
298 ubrlcr |= UBRLCR_EVENPRT;
299 }
300
301
302 ubrlcr |= UBRLCR_FIFOEN;
303
304
305 port->read_status_mask = UARTDR_OVERR;
306 if (termios->c_iflag & INPCK)
307 port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
308
309
310 port->ignore_status_mask = 0;
311 if (!(termios->c_cflag & CREAD))
312 port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
313 UARTDR_FRMERR;
314
315 uart_update_timeout(port, termios->c_cflag, baud);
316
317 writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
318}
319
320static const char *uart_clps711x_type(struct uart_port *port)
321{
322 return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
323}
324
325static void uart_clps711x_config_port(struct uart_port *port, int flags)
326{
327 if (flags & UART_CONFIG_TYPE)
328 port->type = PORT_CLPS711X;
329}
330
331static void uart_clps711x_nop_void(struct uart_port *port)
332{
333}
334
335static int uart_clps711x_nop_int(struct uart_port *port)
336{
337 return 0;
338}
339
340static const struct uart_ops uart_clps711x_ops = {
341 .tx_empty = uart_clps711x_tx_empty,
342 .set_mctrl = uart_clps711x_set_mctrl,
343 .get_mctrl = uart_clps711x_get_mctrl,
344 .stop_tx = uart_clps711x_stop_tx,
345 .start_tx = uart_clps711x_start_tx,
346 .stop_rx = uart_clps711x_nop_void,
347 .break_ctl = uart_clps711x_break_ctl,
348 .set_ldisc = uart_clps711x_set_ldisc,
349 .startup = uart_clps711x_startup,
350 .shutdown = uart_clps711x_shutdown,
351 .set_termios = uart_clps711x_set_termios,
352 .type = uart_clps711x_type,
353 .config_port = uart_clps711x_config_port,
354 .release_port = uart_clps711x_nop_void,
355 .request_port = uart_clps711x_nop_int,
356};
357
358#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
359static void uart_clps711x_console_putchar(struct uart_port *port, int ch)
360{
361 struct clps711x_port *s = dev_get_drvdata(port->dev);
362 u32 sysflg = 0;
363
364
365 do {
366 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
367 } while (sysflg & SYSFLG_UTXFF);
368
369 writew(ch, port->membase + UARTDR_OFFSET);
370}
371
372static void uart_clps711x_console_write(struct console *co, const char *c,
373 unsigned n)
374{
375 struct uart_port *port = clps711x_uart.state[co->index].uart_port;
376 struct clps711x_port *s = dev_get_drvdata(port->dev);
377 u32 sysflg = 0;
378
379 uart_console_write(port, c, n, uart_clps711x_console_putchar);
380
381
382 do {
383 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
384 } while (sysflg & SYSFLG_UBUSY);
385}
386
387static int uart_clps711x_console_setup(struct console *co, char *options)
388{
389 int baud = 38400, bits = 8, parity = 'n', flow = 'n';
390 int ret, index = co->index;
391 struct clps711x_port *s;
392 struct uart_port *port;
393 unsigned int quot;
394 u32 ubrlcr;
395
396 if (index < 0 || index >= UART_CLPS711X_NR)
397 return -EINVAL;
398
399 port = clps711x_uart.state[index].uart_port;
400 if (!port)
401 return -ENODEV;
402
403 s = dev_get_drvdata(port->dev);
404
405 if (!options) {
406 u32 syscon = 0;
407
408 regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
409 if (syscon & SYSCON_UARTEN) {
410 ubrlcr = readl(port->membase + UBRLCR_OFFSET);
411
412 if (ubrlcr & UBRLCR_PRTEN) {
413 if (ubrlcr & UBRLCR_EVENPRT)
414 parity = 'e';
415 else
416 parity = 'o';
417 }
418
419 if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
420 bits = 7;
421
422 quot = ubrlcr & UBRLCR_BAUD_MASK;
423 baud = port->uartclk / (16 * (quot + 1));
424 }
425 } else
426 uart_parse_options(options, &baud, &parity, &bits, &flow);
427
428 ret = uart_set_options(port, co, baud, parity, bits, flow);
429 if (ret)
430 return ret;
431
432 return regmap_update_bits(s->syscon, SYSCON_OFFSET,
433 SYSCON_UARTEN, SYSCON_UARTEN);
434}
435
436static struct console clps711x_console = {
437 .name = UART_CLPS711X_DEVNAME,
438 .device = uart_console_device,
439 .write = uart_clps711x_console_write,
440 .setup = uart_clps711x_console_setup,
441 .flags = CON_PRINTBUFFER,
442 .index = -1,
443};
444#endif
445
446static int uart_clps711x_probe(struct platform_device *pdev)
447{
448 struct device_node *np = pdev->dev.of_node;
449 int ret, index = np ? of_alias_get_id(np, "serial") : pdev->id;
450 struct clps711x_port *s;
451 struct resource *res;
452 struct clk *uart_clk;
453 int irq;
454
455 if (index < 0 || index >= UART_CLPS711X_NR)
456 return -EINVAL;
457
458 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
459 if (!s)
460 return -ENOMEM;
461
462 uart_clk = devm_clk_get(&pdev->dev, NULL);
463 if (IS_ERR(uart_clk))
464 return PTR_ERR(uart_clk);
465
466 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
467 s->port.membase = devm_ioremap_resource(&pdev->dev, res);
468 if (IS_ERR(s->port.membase))
469 return PTR_ERR(s->port.membase);
470
471 irq = platform_get_irq(pdev, 0);
472 if (irq < 0)
473 return irq;
474 s->port.irq = irq;
475
476 s->rx_irq = platform_get_irq(pdev, 1);
477 if (s->rx_irq < 0)
478 return s->rx_irq;
479
480 if (!np) {
481 char syscon_name[9];
482
483 sprintf(syscon_name, "syscon.%i", index + 1);
484 s->syscon = syscon_regmap_lookup_by_pdevname(syscon_name);
485 if (IS_ERR(s->syscon))
486 return PTR_ERR(s->syscon);
487 } else {
488 s->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
489 if (IS_ERR(s->syscon))
490 return PTR_ERR(s->syscon);
491 }
492
493 s->port.line = index;
494 s->port.dev = &pdev->dev;
495 s->port.iotype = UPIO_MEM32;
496 s->port.mapbase = res->start;
497 s->port.type = PORT_CLPS711X;
498 s->port.fifosize = 16;
499 s->port.flags = UPF_SKIP_TEST | UPF_FIXED_TYPE;
500 s->port.uartclk = clk_get_rate(uart_clk);
501 s->port.ops = &uart_clps711x_ops;
502
503 platform_set_drvdata(pdev, s);
504
505 s->gpios = mctrl_gpio_init_noauto(&pdev->dev, 0);
506 if (IS_ERR(s->gpios))
507 return PTR_ERR(s->gpios);
508
509 ret = uart_add_one_port(&clps711x_uart, &s->port);
510 if (ret)
511 return ret;
512
513
514 if (!uart_console(&s->port))
515 regmap_update_bits(s->syscon, SYSCON_OFFSET, SYSCON_UARTEN, 0);
516
517 s->tx_enabled = 1;
518
519 ret = devm_request_irq(&pdev->dev, s->port.irq, uart_clps711x_int_tx, 0,
520 dev_name(&pdev->dev), &s->port);
521 if (ret) {
522 uart_remove_one_port(&clps711x_uart, &s->port);
523 return ret;
524 }
525
526 ret = devm_request_irq(&pdev->dev, s->rx_irq, uart_clps711x_int_rx, 0,
527 dev_name(&pdev->dev), &s->port);
528 if (ret)
529 uart_remove_one_port(&clps711x_uart, &s->port);
530
531 return ret;
532}
533
534static int uart_clps711x_remove(struct platform_device *pdev)
535{
536 struct clps711x_port *s = platform_get_drvdata(pdev);
537
538 return uart_remove_one_port(&clps711x_uart, &s->port);
539}
540
541static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
542 { .compatible = "cirrus,ep7209-uart", },
543 { }
544};
545MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);
546
547static struct platform_driver clps711x_uart_platform = {
548 .driver = {
549 .name = "clps711x-uart",
550 .of_match_table = of_match_ptr(clps711x_uart_dt_ids),
551 },
552 .probe = uart_clps711x_probe,
553 .remove = uart_clps711x_remove,
554};
555
556static int __init uart_clps711x_init(void)
557{
558 int ret;
559
560#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
561 clps711x_uart.cons = &clps711x_console;
562 clps711x_console.data = &clps711x_uart;
563#endif
564
565 ret = uart_register_driver(&clps711x_uart);
566 if (ret)
567 return ret;
568
569 return platform_driver_register(&clps711x_uart_platform);
570}
571module_init(uart_clps711x_init);
572
573static void __exit uart_clps711x_exit(void)
574{
575 platform_driver_unregister(&clps711x_uart_platform);
576 uart_unregister_driver(&clps711x_uart);
577}
578module_exit(uart_clps711x_exit);
579
580MODULE_AUTHOR("Deep Blue Solutions Ltd");
581MODULE_DESCRIPTION("CLPS711X serial driver");
582MODULE_LICENSE("GPL");
583
