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13#include <linux/module.h>
14#include <linux/ioport.h>
15#include <linux/init.h>
16#include <linux/console.h>
17#include <linux/sysrq.h>
18#include <linux/delay.h>
19#include <linux/platform_device.h>
20#include <linux/tty.h>
21#include <linux/tty_flip.h>
22#include <linux/serial_core.h>
23#include <linux/serial.h>
24#include <linux/slab.h>
25#include <linux/io.h>
26#include <linux/irq.h>
27
28#include <asm/div64.h>
29
30#include <asm/mach-ath79/ar933x_uart.h>
31#include <asm/mach-ath79/ar933x_uart_platform.h>
32
33#define DRIVER_NAME "ar933x-uart"
34
35#define AR933X_UART_MAX_SCALE 0xff
36#define AR933X_UART_MAX_STEP 0xffff
37
38#define AR933X_UART_MIN_BAUD 300
39#define AR933X_UART_MAX_BAUD 3000000
40
41#define AR933X_DUMMY_STATUS_RD 0x01
42
43static struct uart_driver ar933x_uart_driver;
44
45struct ar933x_uart_port {
46 struct uart_port port;
47 unsigned int ier;
48 unsigned int min_baud;
49 unsigned int max_baud;
50};
51
52static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
53 int offset)
54{
55 return readl(up->port.membase + offset);
56}
57
58static inline void ar933x_uart_write(struct ar933x_uart_port *up,
59 int offset, unsigned int value)
60{
61 writel(value, up->port.membase + offset);
62}
63
64static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
65 unsigned int offset,
66 unsigned int mask,
67 unsigned int val)
68{
69 unsigned int t;
70
71 t = ar933x_uart_read(up, offset);
72 t &= ~mask;
73 t |= val;
74 ar933x_uart_write(up, offset, t);
75}
76
77static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
78 unsigned int offset,
79 unsigned int val)
80{
81 ar933x_uart_rmw(up, offset, 0, val);
82}
83
84static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
85 unsigned int offset,
86 unsigned int val)
87{
88 ar933x_uart_rmw(up, offset, val, 0);
89}
90
91static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
92{
93 up->ier |= AR933X_UART_INT_TX_EMPTY;
94 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
95}
96
97static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
98{
99 up->ier &= ~AR933X_UART_INT_TX_EMPTY;
100 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
101}
102
103static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
104{
105 unsigned int rdata;
106
107 rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
108 rdata |= AR933X_UART_DATA_TX_CSR;
109 ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
110}
111
112static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
113{
114 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
115 unsigned long flags;
116 unsigned int rdata;
117
118 spin_lock_irqsave(&up->port.lock, flags);
119 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
120 spin_unlock_irqrestore(&up->port.lock, flags);
121
122 return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
123}
124
125static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
126{
127 return TIOCM_CAR;
128}
129
130static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
131{
132}
133
134static void ar933x_uart_start_tx(struct uart_port *port)
135{
136 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
137
138 ar933x_uart_start_tx_interrupt(up);
139}
140
141static void ar933x_uart_stop_tx(struct uart_port *port)
142{
143 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
144
145 ar933x_uart_stop_tx_interrupt(up);
146}
147
148static void ar933x_uart_stop_rx(struct uart_port *port)
149{
150 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
151
152 up->ier &= ~AR933X_UART_INT_RX_VALID;
153 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
154}
155
156static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
157{
158 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
159 unsigned long flags;
160
161 spin_lock_irqsave(&up->port.lock, flags);
162 if (break_state == -1)
163 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
164 AR933X_UART_CS_TX_BREAK);
165 else
166 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
167 AR933X_UART_CS_TX_BREAK);
168 spin_unlock_irqrestore(&up->port.lock, flags);
169}
170
171static void ar933x_uart_enable_ms(struct uart_port *port)
172{
173}
174
175
176
177
178static unsigned long ar933x_uart_get_baud(unsigned int clk,
179 unsigned int scale,
180 unsigned int step)
181{
182 u64 t;
183 u32 div;
184
185 div = (2 << 16) * (scale + 1);
186 t = clk;
187 t *= step;
188 t += (div / 2);
189 do_div(t, div);
190
191 return t;
192}
193
194static void ar933x_uart_get_scale_step(unsigned int clk,
195 unsigned int baud,
196 unsigned int *scale,
197 unsigned int *step)
198{
199 unsigned int tscale;
200 long min_diff;
201
202 *scale = 0;
203 *step = 0;
204
205 min_diff = baud;
206 for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
207 u64 tstep;
208 int diff;
209
210 tstep = baud * (tscale + 1);
211 tstep *= (2 << 16);
212 do_div(tstep, clk);
213
214 if (tstep > AR933X_UART_MAX_STEP)
215 break;
216
217 diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
218 if (diff < min_diff) {
219 min_diff = diff;
220 *scale = tscale;
221 *step = tstep;
222 }
223 }
224}
225
226static void ar933x_uart_set_termios(struct uart_port *port,
227 struct ktermios *new,
228 struct ktermios *old)
229{
230 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
231 unsigned int cs;
232 unsigned long flags;
233 unsigned int baud, scale, step;
234
235
236 new->c_cflag &= ~CSIZE;
237 new->c_cflag |= CS8;
238
239
240 new->c_cflag &= ~CSTOPB;
241
242 cs = 0;
243 if (new->c_cflag & PARENB) {
244 if (!(new->c_cflag & PARODD))
245 cs |= AR933X_UART_CS_PARITY_EVEN;
246 else
247 cs |= AR933X_UART_CS_PARITY_ODD;
248 } else {
249 cs |= AR933X_UART_CS_PARITY_NONE;
250 }
251
252
253 new->c_cflag &= ~CMSPAR;
254
255 baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
256 ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
257
258
259
260
261
262 spin_lock_irqsave(&up->port.lock, flags);
263
264
265 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
266 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
267
268
269 uart_update_timeout(port, new->c_cflag, baud);
270
271 up->port.ignore_status_mask = 0;
272
273
274 if ((new->c_cflag & CREAD) == 0)
275 up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
276
277 ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
278 scale << AR933X_UART_CLOCK_SCALE_S | step);
279
280
281 ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
282
283
284 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
285 AR933X_UART_CS_HOST_INT_EN);
286
287
288 ar933x_uart_rmw(up, AR933X_UART_CS_REG,
289 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
290 AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
291
292 spin_unlock_irqrestore(&up->port.lock, flags);
293
294 if (tty_termios_baud_rate(new))
295 tty_termios_encode_baud_rate(new, baud, baud);
296}
297
298static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
299{
300 struct tty_port *port = &up->port.state->port;
301 int max_count = 256;
302
303 do {
304 unsigned int rdata;
305 unsigned char ch;
306
307 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
308 if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
309 break;
310
311
312 ar933x_uart_write(up, AR933X_UART_DATA_REG,
313 AR933X_UART_DATA_RX_CSR);
314
315 up->port.icount.rx++;
316 ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
317
318 if (uart_handle_sysrq_char(&up->port, ch))
319 continue;
320
321 if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
322 tty_insert_flip_char(port, ch, TTY_NORMAL);
323 } while (max_count-- > 0);
324
325 tty_flip_buffer_push(port);
326}
327
328static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
329{
330 struct circ_buf *xmit = &up->port.state->xmit;
331 int count;
332
333 if (uart_tx_stopped(&up->port))
334 return;
335
336 count = up->port.fifosize;
337 do {
338 unsigned int rdata;
339
340 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
341 if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
342 break;
343
344 if (up->port.x_char) {
345 ar933x_uart_putc(up, up->port.x_char);
346 up->port.icount.tx++;
347 up->port.x_char = 0;
348 continue;
349 }
350
351 if (uart_circ_empty(xmit))
352 break;
353
354 ar933x_uart_putc(up, xmit->buf[xmit->tail]);
355
356 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
357 up->port.icount.tx++;
358 } while (--count > 0);
359
360 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
361 uart_write_wakeup(&up->port);
362
363 if (!uart_circ_empty(xmit))
364 ar933x_uart_start_tx_interrupt(up);
365}
366
367static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
368{
369 struct ar933x_uart_port *up = dev_id;
370 unsigned int status;
371
372 status = ar933x_uart_read(up, AR933X_UART_CS_REG);
373 if ((status & AR933X_UART_CS_HOST_INT) == 0)
374 return IRQ_NONE;
375
376 spin_lock(&up->port.lock);
377
378 status = ar933x_uart_read(up, AR933X_UART_INT_REG);
379 status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
380
381 if (status & AR933X_UART_INT_RX_VALID) {
382 ar933x_uart_write(up, AR933X_UART_INT_REG,
383 AR933X_UART_INT_RX_VALID);
384 ar933x_uart_rx_chars(up);
385 }
386
387 if (status & AR933X_UART_INT_TX_EMPTY) {
388 ar933x_uart_write(up, AR933X_UART_INT_REG,
389 AR933X_UART_INT_TX_EMPTY);
390 ar933x_uart_stop_tx_interrupt(up);
391 ar933x_uart_tx_chars(up);
392 }
393
394 spin_unlock(&up->port.lock);
395
396 return IRQ_HANDLED;
397}
398
399static int ar933x_uart_startup(struct uart_port *port)
400{
401 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
402 unsigned long flags;
403 int ret;
404
405 ret = request_irq(up->port.irq, ar933x_uart_interrupt,
406 up->port.irqflags, dev_name(up->port.dev), up);
407 if (ret)
408 return ret;
409
410 spin_lock_irqsave(&up->port.lock, flags);
411
412
413 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
414 AR933X_UART_CS_HOST_INT_EN);
415
416
417 up->ier = AR933X_UART_INT_RX_VALID;
418 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
419
420 spin_unlock_irqrestore(&up->port.lock, flags);
421
422 return 0;
423}
424
425static void ar933x_uart_shutdown(struct uart_port *port)
426{
427 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
428
429
430 up->ier = 0;
431 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
432
433
434 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
435 AR933X_UART_CS_TX_BREAK);
436
437 free_irq(up->port.irq, up);
438}
439
440static const char *ar933x_uart_type(struct uart_port *port)
441{
442 return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
443}
444
445static void ar933x_uart_release_port(struct uart_port *port)
446{
447
448}
449
450static int ar933x_uart_request_port(struct uart_port *port)
451{
452
453 return 0;
454}
455
456static void ar933x_uart_config_port(struct uart_port *port, int flags)
457{
458 if (flags & UART_CONFIG_TYPE)
459 port->type = PORT_AR933X;
460}
461
462static int ar933x_uart_verify_port(struct uart_port *port,
463 struct serial_struct *ser)
464{
465 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
466
467 if (ser->type != PORT_UNKNOWN &&
468 ser->type != PORT_AR933X)
469 return -EINVAL;
470
471 if (ser->irq < 0 || ser->irq >= NR_IRQS)
472 return -EINVAL;
473
474 if (ser->baud_base < up->min_baud ||
475 ser->baud_base > up->max_baud)
476 return -EINVAL;
477
478 return 0;
479}
480
481static struct uart_ops ar933x_uart_ops = {
482 .tx_empty = ar933x_uart_tx_empty,
483 .set_mctrl = ar933x_uart_set_mctrl,
484 .get_mctrl = ar933x_uart_get_mctrl,
485 .stop_tx = ar933x_uart_stop_tx,
486 .start_tx = ar933x_uart_start_tx,
487 .stop_rx = ar933x_uart_stop_rx,
488 .enable_ms = ar933x_uart_enable_ms,
489 .break_ctl = ar933x_uart_break_ctl,
490 .startup = ar933x_uart_startup,
491 .shutdown = ar933x_uart_shutdown,
492 .set_termios = ar933x_uart_set_termios,
493 .type = ar933x_uart_type,
494 .release_port = ar933x_uart_release_port,
495 .request_port = ar933x_uart_request_port,
496 .config_port = ar933x_uart_config_port,
497 .verify_port = ar933x_uart_verify_port,
498};
499
500#ifdef CONFIG_SERIAL_AR933X_CONSOLE
501
502static struct ar933x_uart_port *
503ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
504
505static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
506{
507 unsigned int status;
508 unsigned int timeout = 60000;
509
510
511 do {
512 status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
513 if (--timeout == 0)
514 break;
515 udelay(1);
516 } while ((status & AR933X_UART_DATA_TX_CSR) == 0);
517}
518
519static void ar933x_uart_console_putchar(struct uart_port *port, int ch)
520{
521 struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
522
523 ar933x_uart_wait_xmitr(up);
524 ar933x_uart_putc(up, ch);
525}
526
527static void ar933x_uart_console_write(struct console *co, const char *s,
528 unsigned int count)
529{
530 struct ar933x_uart_port *up = ar933x_console_ports[co->index];
531 unsigned long flags;
532 unsigned int int_en;
533 int locked = 1;
534
535 local_irq_save(flags);
536
537 if (up->port.sysrq)
538 locked = 0;
539 else if (oops_in_progress)
540 locked = spin_trylock(&up->port.lock);
541 else
542 spin_lock(&up->port.lock);
543
544
545
546
547 int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
548 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);
549
550 uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);
551
552
553
554
555
556 ar933x_uart_wait_xmitr(up);
557 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);
558
559 ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
560
561 if (locked)
562 spin_unlock(&up->port.lock);
563
564 local_irq_restore(flags);
565}
566
567static int ar933x_uart_console_setup(struct console *co, char *options)
568{
569 struct ar933x_uart_port *up;
570 int baud = 115200;
571 int bits = 8;
572 int parity = 'n';
573 int flow = 'n';
574
575 if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
576 return -EINVAL;
577
578 up = ar933x_console_ports[co->index];
579 if (!up)
580 return -ENODEV;
581
582 if (options)
583 uart_parse_options(options, &baud, &parity, &bits, &flow);
584
585 return uart_set_options(&up->port, co, baud, parity, bits, flow);
586}
587
588static struct console ar933x_uart_console = {
589 .name = "ttyATH",
590 .write = ar933x_uart_console_write,
591 .device = uart_console_device,
592 .setup = ar933x_uart_console_setup,
593 .flags = CON_PRINTBUFFER,
594 .index = -1,
595 .data = &ar933x_uart_driver,
596};
597
598static void ar933x_uart_add_console_port(struct ar933x_uart_port *up)
599{
600 ar933x_console_ports[up->port.line] = up;
601}
602
603#define AR933X_SERIAL_CONSOLE (&ar933x_uart_console)
604
605#else
606
607static inline void ar933x_uart_add_console_port(struct ar933x_uart_port *up) {}
608
609#define AR933X_SERIAL_CONSOLE NULL
610
611#endif
612
613static struct uart_driver ar933x_uart_driver = {
614 .owner = THIS_MODULE,
615 .driver_name = DRIVER_NAME,
616 .dev_name = "ttyATH",
617 .nr = CONFIG_SERIAL_AR933X_NR_UARTS,
618 .cons = AR933X_SERIAL_CONSOLE,
619};
620
621static int ar933x_uart_probe(struct platform_device *pdev)
622{
623 struct ar933x_uart_platform_data *pdata;
624 struct ar933x_uart_port *up;
625 struct uart_port *port;
626 struct resource *mem_res;
627 struct resource *irq_res;
628 unsigned int baud;
629 int id;
630 int ret;
631
632 pdata = pdev->dev.platform_data;
633 if (!pdata)
634 return -EINVAL;
635
636 id = pdev->id;
637 if (id == -1)
638 id = 0;
639
640 if (id > CONFIG_SERIAL_AR933X_NR_UARTS)
641 return -EINVAL;
642
643 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
644 if (!mem_res) {
645 dev_err(&pdev->dev, "no MEM resource\n");
646 return -EINVAL;
647 }
648
649 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
650 if (!irq_res) {
651 dev_err(&pdev->dev, "no IRQ resource\n");
652 return -EINVAL;
653 }
654
655 up = kzalloc(sizeof(struct ar933x_uart_port), GFP_KERNEL);
656 if (!up)
657 return -ENOMEM;
658
659 port = &up->port;
660 port->mapbase = mem_res->start;
661
662 port->membase = ioremap(mem_res->start, AR933X_UART_REGS_SIZE);
663 if (!port->membase) {
664 ret = -ENOMEM;
665 goto err_free_up;
666 }
667
668 port->line = id;
669 port->irq = irq_res->start;
670 port->dev = &pdev->dev;
671 port->type = PORT_AR933X;
672 port->iotype = UPIO_MEM32;
673 port->uartclk = pdata->uartclk;
674
675 port->regshift = 2;
676 port->fifosize = AR933X_UART_FIFO_SIZE;
677 port->ops = &ar933x_uart_ops;
678
679 baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
680 up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
681
682 baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
683 up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
684
685 ar933x_uart_add_console_port(up);
686
687 ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
688 if (ret)
689 goto err_unmap;
690
691 platform_set_drvdata(pdev, up);
692 return 0;
693
694err_unmap:
695 iounmap(up->port.membase);
696err_free_up:
697 kfree(up);
698 return ret;
699}
700
701static int ar933x_uart_remove(struct platform_device *pdev)
702{
703 struct ar933x_uart_port *up;
704
705 up = platform_get_drvdata(pdev);
706 platform_set_drvdata(pdev, NULL);
707
708 if (up) {
709 uart_remove_one_port(&ar933x_uart_driver, &up->port);
710 iounmap(up->port.membase);
711 kfree(up);
712 }
713
714 return 0;
715}
716
717static struct platform_driver ar933x_uart_platform_driver = {
718 .probe = ar933x_uart_probe,
719 .remove = ar933x_uart_remove,
720 .driver = {
721 .name = DRIVER_NAME,
722 .owner = THIS_MODULE,
723 },
724};
725
726static int __init ar933x_uart_init(void)
727{
728 int ret;
729
730 ar933x_uart_driver.nr = CONFIG_SERIAL_AR933X_NR_UARTS;
731 ret = uart_register_driver(&ar933x_uart_driver);
732 if (ret)
733 goto err_out;
734
735 ret = platform_driver_register(&ar933x_uart_platform_driver);
736 if (ret)
737 goto err_unregister_uart_driver;
738
739 return 0;
740
741err_unregister_uart_driver:
742 uart_unregister_driver(&ar933x_uart_driver);
743err_out:
744 return ret;
745}
746
747static void __exit ar933x_uart_exit(void)
748{
749 platform_driver_unregister(&ar933x_uart_platform_driver);
750 uart_unregister_driver(&ar933x_uart_driver);
751}
752
753module_init(ar933x_uart_init);
754module_exit(ar933x_uart_exit);
755
756MODULE_DESCRIPTION("Atheros AR933X UART driver");
757MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
758MODULE_LICENSE("GPL v2");
759MODULE_ALIAS("platform:" DRIVER_NAME);
760
