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Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
[deliverable/linux.git] / drivers / tty / serial / atmel_serial.c
1 /*
2 * Driver for Atmel AT91 / AT32 Serial ports
3 * Copyright (C) 2003 Rick Bronson
4 *
5 * Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * DMA support added by Chip Coldwell.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25 #include <linux/module.h>
26 #include <linux/tty.h>
27 #include <linux/ioport.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/serial.h>
31 #include <linux/clk.h>
32 #include <linux/console.h>
33 #include <linux/sysrq.h>
34 #include <linux/tty_flip.h>
35 #include <linux/platform_device.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/dma-mapping.h>
39 #include <linux/atmel_pdc.h>
40 #include <linux/atmel_serial.h>
41 #include <linux/uaccess.h>
42 #include <linux/pinctrl/consumer.h>
43
44 #include <asm/io.h>
45 #include <asm/ioctls.h>
46
47 #include <mach/board.h>
48
49 #ifdef CONFIG_ARM
50 #include <mach/cpu.h>
51 #include <asm/gpio.h>
52 #endif
53
54 #define PDC_BUFFER_SIZE 512
55 /* Revisit: We should calculate this based on the actual port settings */
56 #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
57
58 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
59 #define SUPPORT_SYSRQ
60 #endif
61
62 #include <linux/serial_core.h>
63
64 static void atmel_start_rx(struct uart_port *port);
65 static void atmel_stop_rx(struct uart_port *port);
66
67 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
68
69 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
70 * should coexist with the 8250 driver, such as if we have an external 16C550
71 * UART. */
72 #define SERIAL_ATMEL_MAJOR 204
73 #define MINOR_START 154
74 #define ATMEL_DEVICENAME "ttyAT"
75
76 #else
77
78 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
79 * name, but it is legally reserved for the 8250 driver. */
80 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
81 #define MINOR_START 64
82 #define ATMEL_DEVICENAME "ttyS"
83
84 #endif
85
86 #define ATMEL_ISR_PASS_LIMIT 256
87
88 /* UART registers. CR is write-only, hence no GET macro */
89 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
90 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
91 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
92 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
93 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
94 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
95 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
96 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
97 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
98 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
99 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
100 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
101 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
102
103 /* PDC registers */
104 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
105 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
106
107 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
108 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
109 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
110 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
111 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
112
113 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
114 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
115 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
116
117 static int (*atmel_open_hook)(struct uart_port *);
118 static void (*atmel_close_hook)(struct uart_port *);
119
120 struct atmel_dma_buffer {
121 unsigned char *buf;
122 dma_addr_t dma_addr;
123 unsigned int dma_size;
124 unsigned int ofs;
125 };
126
127 struct atmel_uart_char {
128 u16 status;
129 u16 ch;
130 };
131
132 #define ATMEL_SERIAL_RINGSIZE 1024
133
134 /*
135 * We wrap our port structure around the generic uart_port.
136 */
137 struct atmel_uart_port {
138 struct uart_port uart; /* uart */
139 struct clk *clk; /* uart clock */
140 int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
141 u32 backup_imr; /* IMR saved during suspend */
142 int break_active; /* break being received */
143
144 short use_dma_rx; /* enable PDC receiver */
145 short pdc_rx_idx; /* current PDC RX buffer */
146 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
147
148 short use_dma_tx; /* enable PDC transmitter */
149 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
150
151 struct tasklet_struct tasklet;
152 unsigned int irq_status;
153 unsigned int irq_status_prev;
154
155 struct circ_buf rx_ring;
156
157 struct serial_rs485 rs485; /* rs485 settings */
158 unsigned int tx_done_mask;
159 };
160
161 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
162 static unsigned long atmel_ports_in_use;
163
164 #ifdef SUPPORT_SYSRQ
165 static struct console atmel_console;
166 #endif
167
168 #if defined(CONFIG_OF)
169 static const struct of_device_id atmel_serial_dt_ids[] = {
170 { .compatible = "atmel,at91rm9200-usart" },
171 { .compatible = "atmel,at91sam9260-usart" },
172 { /* sentinel */ }
173 };
174
175 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
176 #endif
177
178 static inline struct atmel_uart_port *
179 to_atmel_uart_port(struct uart_port *uart)
180 {
181 return container_of(uart, struct atmel_uart_port, uart);
182 }
183
184 #ifdef CONFIG_SERIAL_ATMEL_PDC
185 static bool atmel_use_dma_rx(struct uart_port *port)
186 {
187 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
188
189 return atmel_port->use_dma_rx;
190 }
191
192 static bool atmel_use_dma_tx(struct uart_port *port)
193 {
194 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
195
196 return atmel_port->use_dma_tx;
197 }
198 #else
199 static bool atmel_use_dma_rx(struct uart_port *port)
200 {
201 return false;
202 }
203
204 static bool atmel_use_dma_tx(struct uart_port *port)
205 {
206 return false;
207 }
208 #endif
209
210 /* Enable or disable the rs485 support */
211 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
212 {
213 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
214 unsigned int mode;
215 unsigned long flags;
216
217 spin_lock_irqsave(&port->lock, flags);
218
219 /* Disable interrupts */
220 UART_PUT_IDR(port, atmel_port->tx_done_mask);
221
222 mode = UART_GET_MR(port);
223
224 /* Resetting serial mode to RS232 (0x0) */
225 mode &= ~ATMEL_US_USMODE;
226
227 atmel_port->rs485 = *rs485conf;
228
229 if (rs485conf->flags & SER_RS485_ENABLED) {
230 dev_dbg(port->dev, "Setting UART to RS485\n");
231 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
232 if ((rs485conf->delay_rts_after_send) > 0)
233 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
234 mode |= ATMEL_US_USMODE_RS485;
235 } else {
236 dev_dbg(port->dev, "Setting UART to RS232\n");
237 if (atmel_use_dma_tx(port))
238 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
239 ATMEL_US_TXBUFE;
240 else
241 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
242 }
243 UART_PUT_MR(port, mode);
244
245 /* Enable interrupts */
246 UART_PUT_IER(port, atmel_port->tx_done_mask);
247
248 spin_unlock_irqrestore(&port->lock, flags);
249
250 }
251
252 /*
253 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
254 */
255 static u_int atmel_tx_empty(struct uart_port *port)
256 {
257 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
258 }
259
260 /*
261 * Set state of the modem control output lines
262 */
263 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
264 {
265 unsigned int control = 0;
266 unsigned int mode;
267 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
268
269 #ifdef CONFIG_ARCH_AT91RM9200
270 if (cpu_is_at91rm9200()) {
271 /*
272 * AT91RM9200 Errata #39: RTS0 is not internally connected
273 * to PA21. We need to drive the pin manually.
274 */
275 if (port->mapbase == AT91RM9200_BASE_US0) {
276 if (mctrl & TIOCM_RTS)
277 at91_set_gpio_value(AT91_PIN_PA21, 0);
278 else
279 at91_set_gpio_value(AT91_PIN_PA21, 1);
280 }
281 }
282 #endif
283
284 if (mctrl & TIOCM_RTS)
285 control |= ATMEL_US_RTSEN;
286 else
287 control |= ATMEL_US_RTSDIS;
288
289 if (mctrl & TIOCM_DTR)
290 control |= ATMEL_US_DTREN;
291 else
292 control |= ATMEL_US_DTRDIS;
293
294 UART_PUT_CR(port, control);
295
296 /* Local loopback mode? */
297 mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
298 if (mctrl & TIOCM_LOOP)
299 mode |= ATMEL_US_CHMODE_LOC_LOOP;
300 else
301 mode |= ATMEL_US_CHMODE_NORMAL;
302
303 /* Resetting serial mode to RS232 (0x0) */
304 mode &= ~ATMEL_US_USMODE;
305
306 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
307 dev_dbg(port->dev, "Setting UART to RS485\n");
308 if ((atmel_port->rs485.delay_rts_after_send) > 0)
309 UART_PUT_TTGR(port,
310 atmel_port->rs485.delay_rts_after_send);
311 mode |= ATMEL_US_USMODE_RS485;
312 } else {
313 dev_dbg(port->dev, "Setting UART to RS232\n");
314 }
315 UART_PUT_MR(port, mode);
316 }
317
318 /*
319 * Get state of the modem control input lines
320 */
321 static u_int atmel_get_mctrl(struct uart_port *port)
322 {
323 unsigned int status, ret = 0;
324
325 status = UART_GET_CSR(port);
326
327 /*
328 * The control signals are active low.
329 */
330 if (!(status & ATMEL_US_DCD))
331 ret |= TIOCM_CD;
332 if (!(status & ATMEL_US_CTS))
333 ret |= TIOCM_CTS;
334 if (!(status & ATMEL_US_DSR))
335 ret |= TIOCM_DSR;
336 if (!(status & ATMEL_US_RI))
337 ret |= TIOCM_RI;
338
339 return ret;
340 }
341
342 /*
343 * Stop transmitting.
344 */
345 static void atmel_stop_tx(struct uart_port *port)
346 {
347 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
348
349 if (atmel_use_dma_tx(port)) {
350 /* disable PDC transmit */
351 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
352 }
353 /* Disable interrupts */
354 UART_PUT_IDR(port, atmel_port->tx_done_mask);
355
356 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
357 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
358 atmel_start_rx(port);
359 }
360
361 /*
362 * Start transmitting.
363 */
364 static void atmel_start_tx(struct uart_port *port)
365 {
366 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
367
368 if (atmel_use_dma_tx(port)) {
369 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
370 /* The transmitter is already running. Yes, we
371 really need this.*/
372 return;
373
374 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
375 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
376 atmel_stop_rx(port);
377
378 /* re-enable PDC transmit */
379 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
380 }
381 /* Enable interrupts */
382 UART_PUT_IER(port, atmel_port->tx_done_mask);
383 }
384
385 /*
386 * start receiving - port is in process of being opened.
387 */
388 static void atmel_start_rx(struct uart_port *port)
389 {
390 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
391
392 UART_PUT_CR(port, ATMEL_US_RXEN);
393
394 if (atmel_use_dma_rx(port)) {
395 /* enable PDC controller */
396 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
397 port->read_status_mask);
398 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
399 } else {
400 UART_PUT_IER(port, ATMEL_US_RXRDY);
401 }
402 }
403
404 /*
405 * Stop receiving - port is in process of being closed.
406 */
407 static void atmel_stop_rx(struct uart_port *port)
408 {
409 UART_PUT_CR(port, ATMEL_US_RXDIS);
410
411 if (atmel_use_dma_rx(port)) {
412 /* disable PDC receive */
413 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
414 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
415 port->read_status_mask);
416 } else {
417 UART_PUT_IDR(port, ATMEL_US_RXRDY);
418 }
419 }
420
421 /*
422 * Enable modem status interrupts
423 */
424 static void atmel_enable_ms(struct uart_port *port)
425 {
426 UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
427 | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
428 }
429
430 /*
431 * Control the transmission of a break signal
432 */
433 static void atmel_break_ctl(struct uart_port *port, int break_state)
434 {
435 if (break_state != 0)
436 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
437 else
438 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
439 }
440
441 /*
442 * Stores the incoming character in the ring buffer
443 */
444 static void
445 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
446 unsigned int ch)
447 {
448 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
449 struct circ_buf *ring = &atmel_port->rx_ring;
450 struct atmel_uart_char *c;
451
452 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
453 /* Buffer overflow, ignore char */
454 return;
455
456 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
457 c->status = status;
458 c->ch = ch;
459
460 /* Make sure the character is stored before we update head. */
461 smp_wmb();
462
463 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
464 }
465
466 /*
467 * Deal with parity, framing and overrun errors.
468 */
469 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
470 {
471 /* clear error */
472 UART_PUT_CR(port, ATMEL_US_RSTSTA);
473
474 if (status & ATMEL_US_RXBRK) {
475 /* ignore side-effect */
476 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
477 port->icount.brk++;
478 }
479 if (status & ATMEL_US_PARE)
480 port->icount.parity++;
481 if (status & ATMEL_US_FRAME)
482 port->icount.frame++;
483 if (status & ATMEL_US_OVRE)
484 port->icount.overrun++;
485 }
486
487 /*
488 * Characters received (called from interrupt handler)
489 */
490 static void atmel_rx_chars(struct uart_port *port)
491 {
492 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
493 unsigned int status, ch;
494
495 status = UART_GET_CSR(port);
496 while (status & ATMEL_US_RXRDY) {
497 ch = UART_GET_CHAR(port);
498
499 /*
500 * note that the error handling code is
501 * out of the main execution path
502 */
503 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
504 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
505 || atmel_port->break_active)) {
506
507 /* clear error */
508 UART_PUT_CR(port, ATMEL_US_RSTSTA);
509
510 if (status & ATMEL_US_RXBRK
511 && !atmel_port->break_active) {
512 atmel_port->break_active = 1;
513 UART_PUT_IER(port, ATMEL_US_RXBRK);
514 } else {
515 /*
516 * This is either the end-of-break
517 * condition or we've received at
518 * least one character without RXBRK
519 * being set. In both cases, the next
520 * RXBRK will indicate start-of-break.
521 */
522 UART_PUT_IDR(port, ATMEL_US_RXBRK);
523 status &= ~ATMEL_US_RXBRK;
524 atmel_port->break_active = 0;
525 }
526 }
527
528 atmel_buffer_rx_char(port, status, ch);
529 status = UART_GET_CSR(port);
530 }
531
532 tasklet_schedule(&atmel_port->tasklet);
533 }
534
535 /*
536 * Transmit characters (called from tasklet with TXRDY interrupt
537 * disabled)
538 */
539 static void atmel_tx_chars(struct uart_port *port)
540 {
541 struct circ_buf *xmit = &port->state->xmit;
542 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
543
544 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
545 UART_PUT_CHAR(port, port->x_char);
546 port->icount.tx++;
547 port->x_char = 0;
548 }
549 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
550 return;
551
552 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
553 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
554 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
555 port->icount.tx++;
556 if (uart_circ_empty(xmit))
557 break;
558 }
559
560 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
561 uart_write_wakeup(port);
562
563 if (!uart_circ_empty(xmit))
564 /* Enable interrupts */
565 UART_PUT_IER(port, atmel_port->tx_done_mask);
566 }
567
568 /*
569 * receive interrupt handler.
570 */
571 static void
572 atmel_handle_receive(struct uart_port *port, unsigned int pending)
573 {
574 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
575
576 if (atmel_use_dma_rx(port)) {
577 /*
578 * PDC receive. Just schedule the tasklet and let it
579 * figure out the details.
580 *
581 * TODO: We're not handling error flags correctly at
582 * the moment.
583 */
584 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
585 UART_PUT_IDR(port, (ATMEL_US_ENDRX
586 | ATMEL_US_TIMEOUT));
587 tasklet_schedule(&atmel_port->tasklet);
588 }
589
590 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
591 ATMEL_US_FRAME | ATMEL_US_PARE))
592 atmel_pdc_rxerr(port, pending);
593 }
594
595 /* Interrupt receive */
596 if (pending & ATMEL_US_RXRDY)
597 atmel_rx_chars(port);
598 else if (pending & ATMEL_US_RXBRK) {
599 /*
600 * End of break detected. If it came along with a
601 * character, atmel_rx_chars will handle it.
602 */
603 UART_PUT_CR(port, ATMEL_US_RSTSTA);
604 UART_PUT_IDR(port, ATMEL_US_RXBRK);
605 atmel_port->break_active = 0;
606 }
607 }
608
609 /*
610 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
611 */
612 static void
613 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
614 {
615 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
616
617 if (pending & atmel_port->tx_done_mask) {
618 /* Either PDC or interrupt transmission */
619 UART_PUT_IDR(port, atmel_port->tx_done_mask);
620 tasklet_schedule(&atmel_port->tasklet);
621 }
622 }
623
624 /*
625 * status flags interrupt handler.
626 */
627 static void
628 atmel_handle_status(struct uart_port *port, unsigned int pending,
629 unsigned int status)
630 {
631 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
632
633 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
634 | ATMEL_US_CTSIC)) {
635 atmel_port->irq_status = status;
636 tasklet_schedule(&atmel_port->tasklet);
637 }
638 }
639
640 /*
641 * Interrupt handler
642 */
643 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
644 {
645 struct uart_port *port = dev_id;
646 unsigned int status, pending, pass_counter = 0;
647
648 do {
649 status = UART_GET_CSR(port);
650 pending = status & UART_GET_IMR(port);
651 if (!pending)
652 break;
653
654 atmel_handle_receive(port, pending);
655 atmel_handle_status(port, pending, status);
656 atmel_handle_transmit(port, pending);
657 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
658
659 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
660 }
661
662 /*
663 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
664 */
665 static void atmel_tx_dma(struct uart_port *port)
666 {
667 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
668 struct circ_buf *xmit = &port->state->xmit;
669 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
670 int count;
671
672 /* nothing left to transmit? */
673 if (UART_GET_TCR(port))
674 return;
675
676 xmit->tail += pdc->ofs;
677 xmit->tail &= UART_XMIT_SIZE - 1;
678
679 port->icount.tx += pdc->ofs;
680 pdc->ofs = 0;
681
682 /* more to transmit - setup next transfer */
683
684 /* disable PDC transmit */
685 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
686
687 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
688 dma_sync_single_for_device(port->dev,
689 pdc->dma_addr,
690 pdc->dma_size,
691 DMA_TO_DEVICE);
692
693 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
694 pdc->ofs = count;
695
696 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
697 UART_PUT_TCR(port, count);
698 /* re-enable PDC transmit */
699 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
700 /* Enable interrupts */
701 UART_PUT_IER(port, atmel_port->tx_done_mask);
702 } else {
703 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
704 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
705 /* DMA done, stop TX, start RX for RS485 */
706 atmel_start_rx(port);
707 }
708 }
709
710 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
711 uart_write_wakeup(port);
712 }
713
714 static void atmel_rx_from_ring(struct uart_port *port)
715 {
716 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
717 struct circ_buf *ring = &atmel_port->rx_ring;
718 unsigned int flg;
719 unsigned int status;
720
721 while (ring->head != ring->tail) {
722 struct atmel_uart_char c;
723
724 /* Make sure c is loaded after head. */
725 smp_rmb();
726
727 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
728
729 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
730
731 port->icount.rx++;
732 status = c.status;
733 flg = TTY_NORMAL;
734
735 /*
736 * note that the error handling code is
737 * out of the main execution path
738 */
739 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
740 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
741 if (status & ATMEL_US_RXBRK) {
742 /* ignore side-effect */
743 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
744
745 port->icount.brk++;
746 if (uart_handle_break(port))
747 continue;
748 }
749 if (status & ATMEL_US_PARE)
750 port->icount.parity++;
751 if (status & ATMEL_US_FRAME)
752 port->icount.frame++;
753 if (status & ATMEL_US_OVRE)
754 port->icount.overrun++;
755
756 status &= port->read_status_mask;
757
758 if (status & ATMEL_US_RXBRK)
759 flg = TTY_BREAK;
760 else if (status & ATMEL_US_PARE)
761 flg = TTY_PARITY;
762 else if (status & ATMEL_US_FRAME)
763 flg = TTY_FRAME;
764 }
765
766
767 if (uart_handle_sysrq_char(port, c.ch))
768 continue;
769
770 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
771 }
772
773 /*
774 * Drop the lock here since it might end up calling
775 * uart_start(), which takes the lock.
776 */
777 spin_unlock(&port->lock);
778 tty_flip_buffer_push(port->state->port.tty);
779 spin_lock(&port->lock);
780 }
781
782 static void atmel_rx_from_dma(struct uart_port *port)
783 {
784 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
785 struct tty_struct *tty = port->state->port.tty;
786 struct atmel_dma_buffer *pdc;
787 int rx_idx = atmel_port->pdc_rx_idx;
788 unsigned int head;
789 unsigned int tail;
790 unsigned int count;
791
792 do {
793 /* Reset the UART timeout early so that we don't miss one */
794 UART_PUT_CR(port, ATMEL_US_STTTO);
795
796 pdc = &atmel_port->pdc_rx[rx_idx];
797 head = UART_GET_RPR(port) - pdc->dma_addr;
798 tail = pdc->ofs;
799
800 /* If the PDC has switched buffers, RPR won't contain
801 * any address within the current buffer. Since head
802 * is unsigned, we just need a one-way comparison to
803 * find out.
804 *
805 * In this case, we just need to consume the entire
806 * buffer and resubmit it for DMA. This will clear the
807 * ENDRX bit as well, so that we can safely re-enable
808 * all interrupts below.
809 */
810 head = min(head, pdc->dma_size);
811
812 if (likely(head != tail)) {
813 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
814 pdc->dma_size, DMA_FROM_DEVICE);
815
816 /*
817 * head will only wrap around when we recycle
818 * the DMA buffer, and when that happens, we
819 * explicitly set tail to 0. So head will
820 * always be greater than tail.
821 */
822 count = head - tail;
823
824 tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
825
826 dma_sync_single_for_device(port->dev, pdc->dma_addr,
827 pdc->dma_size, DMA_FROM_DEVICE);
828
829 port->icount.rx += count;
830 pdc->ofs = head;
831 }
832
833 /*
834 * If the current buffer is full, we need to check if
835 * the next one contains any additional data.
836 */
837 if (head >= pdc->dma_size) {
838 pdc->ofs = 0;
839 UART_PUT_RNPR(port, pdc->dma_addr);
840 UART_PUT_RNCR(port, pdc->dma_size);
841
842 rx_idx = !rx_idx;
843 atmel_port->pdc_rx_idx = rx_idx;
844 }
845 } while (head >= pdc->dma_size);
846
847 /*
848 * Drop the lock here since it might end up calling
849 * uart_start(), which takes the lock.
850 */
851 spin_unlock(&port->lock);
852 tty_flip_buffer_push(tty);
853 spin_lock(&port->lock);
854
855 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
856 }
857
858 /*
859 * tasklet handling tty stuff outside the interrupt handler.
860 */
861 static void atmel_tasklet_func(unsigned long data)
862 {
863 struct uart_port *port = (struct uart_port *)data;
864 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
865 unsigned int status;
866 unsigned int status_change;
867
868 /* The interrupt handler does not take the lock */
869 spin_lock(&port->lock);
870
871 if (atmel_use_dma_tx(port))
872 atmel_tx_dma(port);
873 else
874 atmel_tx_chars(port);
875
876 status = atmel_port->irq_status;
877 status_change = status ^ atmel_port->irq_status_prev;
878
879 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
880 | ATMEL_US_DCD | ATMEL_US_CTS)) {
881 /* TODO: All reads to CSR will clear these interrupts! */
882 if (status_change & ATMEL_US_RI)
883 port->icount.rng++;
884 if (status_change & ATMEL_US_DSR)
885 port->icount.dsr++;
886 if (status_change & ATMEL_US_DCD)
887 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
888 if (status_change & ATMEL_US_CTS)
889 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
890
891 wake_up_interruptible(&port->state->port.delta_msr_wait);
892
893 atmel_port->irq_status_prev = status;
894 }
895
896 if (atmel_use_dma_rx(port))
897 atmel_rx_from_dma(port);
898 else
899 atmel_rx_from_ring(port);
900
901 spin_unlock(&port->lock);
902 }
903
904 /*
905 * Perform initialization and enable port for reception
906 */
907 static int atmel_startup(struct uart_port *port)
908 {
909 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
910 struct tty_struct *tty = port->state->port.tty;
911 int retval;
912
913 /*
914 * Ensure that no interrupts are enabled otherwise when
915 * request_irq() is called we could get stuck trying to
916 * handle an unexpected interrupt
917 */
918 UART_PUT_IDR(port, -1);
919
920 /*
921 * Allocate the IRQ
922 */
923 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
924 tty ? tty->name : "atmel_serial", port);
925 if (retval) {
926 printk("atmel_serial: atmel_startup - Can't get irq\n");
927 return retval;
928 }
929
930 /*
931 * Initialize DMA (if necessary)
932 */
933 if (atmel_use_dma_rx(port)) {
934 int i;
935
936 for (i = 0; i < 2; i++) {
937 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
938
939 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
940 if (pdc->buf == NULL) {
941 if (i != 0) {
942 dma_unmap_single(port->dev,
943 atmel_port->pdc_rx[0].dma_addr,
944 PDC_BUFFER_SIZE,
945 DMA_FROM_DEVICE);
946 kfree(atmel_port->pdc_rx[0].buf);
947 }
948 free_irq(port->irq, port);
949 return -ENOMEM;
950 }
951 pdc->dma_addr = dma_map_single(port->dev,
952 pdc->buf,
953 PDC_BUFFER_SIZE,
954 DMA_FROM_DEVICE);
955 pdc->dma_size = PDC_BUFFER_SIZE;
956 pdc->ofs = 0;
957 }
958
959 atmel_port->pdc_rx_idx = 0;
960
961 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
962 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
963
964 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
965 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
966 }
967 if (atmel_use_dma_tx(port)) {
968 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
969 struct circ_buf *xmit = &port->state->xmit;
970
971 pdc->buf = xmit->buf;
972 pdc->dma_addr = dma_map_single(port->dev,
973 pdc->buf,
974 UART_XMIT_SIZE,
975 DMA_TO_DEVICE);
976 pdc->dma_size = UART_XMIT_SIZE;
977 pdc->ofs = 0;
978 }
979
980 /*
981 * If there is a specific "open" function (to register
982 * control line interrupts)
983 */
984 if (atmel_open_hook) {
985 retval = atmel_open_hook(port);
986 if (retval) {
987 free_irq(port->irq, port);
988 return retval;
989 }
990 }
991
992 /* Save current CSR for comparison in atmel_tasklet_func() */
993 atmel_port->irq_status_prev = UART_GET_CSR(port);
994 atmel_port->irq_status = atmel_port->irq_status_prev;
995
996 /*
997 * Finally, enable the serial port
998 */
999 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1000 /* enable xmit & rcvr */
1001 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1002
1003 if (atmel_use_dma_rx(port)) {
1004 /* set UART timeout */
1005 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1006 UART_PUT_CR(port, ATMEL_US_STTTO);
1007
1008 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1009 /* enable PDC controller */
1010 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1011 } else {
1012 /* enable receive only */
1013 UART_PUT_IER(port, ATMEL_US_RXRDY);
1014 }
1015
1016 return 0;
1017 }
1018
1019 /*
1020 * Disable the port
1021 */
1022 static void atmel_shutdown(struct uart_port *port)
1023 {
1024 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1025 /*
1026 * Ensure everything is stopped.
1027 */
1028 atmel_stop_rx(port);
1029 atmel_stop_tx(port);
1030
1031 /*
1032 * Shut-down the DMA.
1033 */
1034 if (atmel_use_dma_rx(port)) {
1035 int i;
1036
1037 for (i = 0; i < 2; i++) {
1038 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1039
1040 dma_unmap_single(port->dev,
1041 pdc->dma_addr,
1042 pdc->dma_size,
1043 DMA_FROM_DEVICE);
1044 kfree(pdc->buf);
1045 }
1046 }
1047 if (atmel_use_dma_tx(port)) {
1048 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1049
1050 dma_unmap_single(port->dev,
1051 pdc->dma_addr,
1052 pdc->dma_size,
1053 DMA_TO_DEVICE);
1054 }
1055
1056 /*
1057 * Disable all interrupts, port and break condition.
1058 */
1059 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1060 UART_PUT_IDR(port, -1);
1061
1062 /*
1063 * Free the interrupt
1064 */
1065 free_irq(port->irq, port);
1066
1067 /*
1068 * If there is a specific "close" function (to unregister
1069 * control line interrupts)
1070 */
1071 if (atmel_close_hook)
1072 atmel_close_hook(port);
1073 }
1074
1075 /*
1076 * Flush any TX data submitted for DMA. Called when the TX circular
1077 * buffer is reset.
1078 */
1079 static void atmel_flush_buffer(struct uart_port *port)
1080 {
1081 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1082
1083 if (atmel_use_dma_tx(port)) {
1084 UART_PUT_TCR(port, 0);
1085 atmel_port->pdc_tx.ofs = 0;
1086 }
1087 }
1088
1089 /*
1090 * Power / Clock management.
1091 */
1092 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1093 unsigned int oldstate)
1094 {
1095 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1096
1097 switch (state) {
1098 case 0:
1099 /*
1100 * Enable the peripheral clock for this serial port.
1101 * This is called on uart_open() or a resume event.
1102 */
1103 clk_enable(atmel_port->clk);
1104
1105 /* re-enable interrupts if we disabled some on suspend */
1106 UART_PUT_IER(port, atmel_port->backup_imr);
1107 break;
1108 case 3:
1109 /* Back up the interrupt mask and disable all interrupts */
1110 atmel_port->backup_imr = UART_GET_IMR(port);
1111 UART_PUT_IDR(port, -1);
1112
1113 /*
1114 * Disable the peripheral clock for this serial port.
1115 * This is called on uart_close() or a suspend event.
1116 */
1117 clk_disable(atmel_port->clk);
1118 break;
1119 default:
1120 printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
1121 }
1122 }
1123
1124 /*
1125 * Change the port parameters
1126 */
1127 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1128 struct ktermios *old)
1129 {
1130 unsigned long flags;
1131 unsigned int mode, imr, quot, baud;
1132 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1133
1134 /* Get current mode register */
1135 mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
1136 | ATMEL_US_NBSTOP | ATMEL_US_PAR
1137 | ATMEL_US_USMODE);
1138
1139 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1140 quot = uart_get_divisor(port, baud);
1141
1142 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1143 quot /= 8;
1144 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1145 }
1146
1147 /* byte size */
1148 switch (termios->c_cflag & CSIZE) {
1149 case CS5:
1150 mode |= ATMEL_US_CHRL_5;
1151 break;
1152 case CS6:
1153 mode |= ATMEL_US_CHRL_6;
1154 break;
1155 case CS7:
1156 mode |= ATMEL_US_CHRL_7;
1157 break;
1158 default:
1159 mode |= ATMEL_US_CHRL_8;
1160 break;
1161 }
1162
1163 /* stop bits */
1164 if (termios->c_cflag & CSTOPB)
1165 mode |= ATMEL_US_NBSTOP_2;
1166
1167 /* parity */
1168 if (termios->c_cflag & PARENB) {
1169 /* Mark or Space parity */
1170 if (termios->c_cflag & CMSPAR) {
1171 if (termios->c_cflag & PARODD)
1172 mode |= ATMEL_US_PAR_MARK;
1173 else
1174 mode |= ATMEL_US_PAR_SPACE;
1175 } else if (termios->c_cflag & PARODD)
1176 mode |= ATMEL_US_PAR_ODD;
1177 else
1178 mode |= ATMEL_US_PAR_EVEN;
1179 } else
1180 mode |= ATMEL_US_PAR_NONE;
1181
1182 /* hardware handshake (RTS/CTS) */
1183 if (termios->c_cflag & CRTSCTS)
1184 mode |= ATMEL_US_USMODE_HWHS;
1185 else
1186 mode |= ATMEL_US_USMODE_NORMAL;
1187
1188 spin_lock_irqsave(&port->lock, flags);
1189
1190 port->read_status_mask = ATMEL_US_OVRE;
1191 if (termios->c_iflag & INPCK)
1192 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1193 if (termios->c_iflag & (BRKINT | PARMRK))
1194 port->read_status_mask |= ATMEL_US_RXBRK;
1195
1196 if (atmel_use_dma_rx(port))
1197 /* need to enable error interrupts */
1198 UART_PUT_IER(port, port->read_status_mask);
1199
1200 /*
1201 * Characters to ignore
1202 */
1203 port->ignore_status_mask = 0;
1204 if (termios->c_iflag & IGNPAR)
1205 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1206 if (termios->c_iflag & IGNBRK) {
1207 port->ignore_status_mask |= ATMEL_US_RXBRK;
1208 /*
1209 * If we're ignoring parity and break indicators,
1210 * ignore overruns too (for real raw support).
1211 */
1212 if (termios->c_iflag & IGNPAR)
1213 port->ignore_status_mask |= ATMEL_US_OVRE;
1214 }
1215 /* TODO: Ignore all characters if CREAD is set.*/
1216
1217 /* update the per-port timeout */
1218 uart_update_timeout(port, termios->c_cflag, baud);
1219
1220 /*
1221 * save/disable interrupts. The tty layer will ensure that the
1222 * transmitter is empty if requested by the caller, so there's
1223 * no need to wait for it here.
1224 */
1225 imr = UART_GET_IMR(port);
1226 UART_PUT_IDR(port, -1);
1227
1228 /* disable receiver and transmitter */
1229 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
1230
1231 /* Resetting serial mode to RS232 (0x0) */
1232 mode &= ~ATMEL_US_USMODE;
1233
1234 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
1235 dev_dbg(port->dev, "Setting UART to RS485\n");
1236 if ((atmel_port->rs485.delay_rts_after_send) > 0)
1237 UART_PUT_TTGR(port,
1238 atmel_port->rs485.delay_rts_after_send);
1239 mode |= ATMEL_US_USMODE_RS485;
1240 } else {
1241 dev_dbg(port->dev, "Setting UART to RS232\n");
1242 }
1243
1244 /* set the parity, stop bits and data size */
1245 UART_PUT_MR(port, mode);
1246
1247 /* set the baud rate */
1248 UART_PUT_BRGR(port, quot);
1249 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1250 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1251
1252 /* restore interrupts */
1253 UART_PUT_IER(port, imr);
1254
1255 /* CTS flow-control and modem-status interrupts */
1256 if (UART_ENABLE_MS(port, termios->c_cflag))
1257 port->ops->enable_ms(port);
1258
1259 spin_unlock_irqrestore(&port->lock, flags);
1260 }
1261
1262 static void atmel_set_ldisc(struct uart_port *port, int new)
1263 {
1264 if (new == N_PPS) {
1265 port->flags |= UPF_HARDPPS_CD;
1266 atmel_enable_ms(port);
1267 } else {
1268 port->flags &= ~UPF_HARDPPS_CD;
1269 }
1270 }
1271
1272 /*
1273 * Return string describing the specified port
1274 */
1275 static const char *atmel_type(struct uart_port *port)
1276 {
1277 return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
1278 }
1279
1280 /*
1281 * Release the memory region(s) being used by 'port'.
1282 */
1283 static void atmel_release_port(struct uart_port *port)
1284 {
1285 struct platform_device *pdev = to_platform_device(port->dev);
1286 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1287
1288 release_mem_region(port->mapbase, size);
1289
1290 if (port->flags & UPF_IOREMAP) {
1291 iounmap(port->membase);
1292 port->membase = NULL;
1293 }
1294 }
1295
1296 /*
1297 * Request the memory region(s) being used by 'port'.
1298 */
1299 static int atmel_request_port(struct uart_port *port)
1300 {
1301 struct platform_device *pdev = to_platform_device(port->dev);
1302 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1303
1304 if (!request_mem_region(port->mapbase, size, "atmel_serial"))
1305 return -EBUSY;
1306
1307 if (port->flags & UPF_IOREMAP) {
1308 port->membase = ioremap(port->mapbase, size);
1309 if (port->membase == NULL) {
1310 release_mem_region(port->mapbase, size);
1311 return -ENOMEM;
1312 }
1313 }
1314
1315 return 0;
1316 }
1317
1318 /*
1319 * Configure/autoconfigure the port.
1320 */
1321 static void atmel_config_port(struct uart_port *port, int flags)
1322 {
1323 if (flags & UART_CONFIG_TYPE) {
1324 port->type = PORT_ATMEL;
1325 atmel_request_port(port);
1326 }
1327 }
1328
1329 /*
1330 * Verify the new serial_struct (for TIOCSSERIAL).
1331 */
1332 static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
1333 {
1334 int ret = 0;
1335 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
1336 ret = -EINVAL;
1337 if (port->irq != ser->irq)
1338 ret = -EINVAL;
1339 if (ser->io_type != SERIAL_IO_MEM)
1340 ret = -EINVAL;
1341 if (port->uartclk / 16 != ser->baud_base)
1342 ret = -EINVAL;
1343 if ((void *)port->mapbase != ser->iomem_base)
1344 ret = -EINVAL;
1345 if (port->iobase != ser->port)
1346 ret = -EINVAL;
1347 if (ser->hub6 != 0)
1348 ret = -EINVAL;
1349 return ret;
1350 }
1351
1352 #ifdef CONFIG_CONSOLE_POLL
1353 static int atmel_poll_get_char(struct uart_port *port)
1354 {
1355 while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
1356 cpu_relax();
1357
1358 return UART_GET_CHAR(port);
1359 }
1360
1361 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
1362 {
1363 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1364 cpu_relax();
1365
1366 UART_PUT_CHAR(port, ch);
1367 }
1368 #endif
1369
1370 static int
1371 atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
1372 {
1373 struct serial_rs485 rs485conf;
1374
1375 switch (cmd) {
1376 case TIOCSRS485:
1377 if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
1378 sizeof(rs485conf)))
1379 return -EFAULT;
1380
1381 atmel_config_rs485(port, &rs485conf);
1382 break;
1383
1384 case TIOCGRS485:
1385 if (copy_to_user((struct serial_rs485 *) arg,
1386 &(to_atmel_uart_port(port)->rs485),
1387 sizeof(rs485conf)))
1388 return -EFAULT;
1389 break;
1390
1391 default:
1392 return -ENOIOCTLCMD;
1393 }
1394 return 0;
1395 }
1396
1397
1398
1399 static struct uart_ops atmel_pops = {
1400 .tx_empty = atmel_tx_empty,
1401 .set_mctrl = atmel_set_mctrl,
1402 .get_mctrl = atmel_get_mctrl,
1403 .stop_tx = atmel_stop_tx,
1404 .start_tx = atmel_start_tx,
1405 .stop_rx = atmel_stop_rx,
1406 .enable_ms = atmel_enable_ms,
1407 .break_ctl = atmel_break_ctl,
1408 .startup = atmel_startup,
1409 .shutdown = atmel_shutdown,
1410 .flush_buffer = atmel_flush_buffer,
1411 .set_termios = atmel_set_termios,
1412 .set_ldisc = atmel_set_ldisc,
1413 .type = atmel_type,
1414 .release_port = atmel_release_port,
1415 .request_port = atmel_request_port,
1416 .config_port = atmel_config_port,
1417 .verify_port = atmel_verify_port,
1418 .pm = atmel_serial_pm,
1419 .ioctl = atmel_ioctl,
1420 #ifdef CONFIG_CONSOLE_POLL
1421 .poll_get_char = atmel_poll_get_char,
1422 .poll_put_char = atmel_poll_put_char,
1423 #endif
1424 };
1425
1426 static void atmel_of_init_port(struct atmel_uart_port *atmel_port,
1427 struct device_node *np)
1428 {
1429 u32 rs485_delay[2];
1430
1431 /* DMA/PDC usage specification */
1432 if (of_get_property(np, "atmel,use-dma-rx", NULL))
1433 atmel_port->use_dma_rx = 1;
1434 else
1435 atmel_port->use_dma_rx = 0;
1436 if (of_get_property(np, "atmel,use-dma-tx", NULL))
1437 atmel_port->use_dma_tx = 1;
1438 else
1439 atmel_port->use_dma_tx = 0;
1440
1441 /* rs485 properties */
1442 if (of_property_read_u32_array(np, "rs485-rts-delay",
1443 rs485_delay, 2) == 0) {
1444 struct serial_rs485 *rs485conf = &atmel_port->rs485;
1445
1446 rs485conf->delay_rts_before_send = rs485_delay[0];
1447 rs485conf->delay_rts_after_send = rs485_delay[1];
1448 rs485conf->flags = 0;
1449
1450 if (of_get_property(np, "rs485-rx-during-tx", NULL))
1451 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1452
1453 if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
1454 rs485conf->flags |= SER_RS485_ENABLED;
1455 }
1456 }
1457
1458 /*
1459 * Configure the port from the platform device resource info.
1460 */
1461 static void atmel_init_port(struct atmel_uart_port *atmel_port,
1462 struct platform_device *pdev)
1463 {
1464 struct uart_port *port = &atmel_port->uart;
1465 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1466
1467 if (pdev->dev.of_node) {
1468 atmel_of_init_port(atmel_port, pdev->dev.of_node);
1469 } else {
1470 atmel_port->use_dma_rx = pdata->use_dma_rx;
1471 atmel_port->use_dma_tx = pdata->use_dma_tx;
1472 atmel_port->rs485 = pdata->rs485;
1473 }
1474
1475 port->iotype = UPIO_MEM;
1476 port->flags = UPF_BOOT_AUTOCONF;
1477 port->ops = &atmel_pops;
1478 port->fifosize = 1;
1479 port->dev = &pdev->dev;
1480 port->mapbase = pdev->resource[0].start;
1481 port->irq = pdev->resource[1].start;
1482
1483 tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
1484 (unsigned long)port);
1485
1486 memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
1487
1488 if (pdata && pdata->regs) {
1489 /* Already mapped by setup code */
1490 port->membase = pdata->regs;
1491 } else {
1492 port->flags |= UPF_IOREMAP;
1493 port->membase = NULL;
1494 }
1495
1496 /* for console, the clock could already be configured */
1497 if (!atmel_port->clk) {
1498 atmel_port->clk = clk_get(&pdev->dev, "usart");
1499 clk_enable(atmel_port->clk);
1500 port->uartclk = clk_get_rate(atmel_port->clk);
1501 clk_disable(atmel_port->clk);
1502 /* only enable clock when USART is in use */
1503 }
1504
1505 /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
1506 if (atmel_port->rs485.flags & SER_RS485_ENABLED)
1507 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
1508 else if (atmel_use_dma_tx(port)) {
1509 port->fifosize = PDC_BUFFER_SIZE;
1510 atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
1511 } else {
1512 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
1513 }
1514 }
1515
1516 struct platform_device *atmel_default_console_device; /* the serial console device */
1517
1518 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1519 static void atmel_console_putchar(struct uart_port *port, int ch)
1520 {
1521 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1522 cpu_relax();
1523 UART_PUT_CHAR(port, ch);
1524 }
1525
1526 /*
1527 * Interrupts are disabled on entering
1528 */
1529 static void atmel_console_write(struct console *co, const char *s, u_int count)
1530 {
1531 struct uart_port *port = &atmel_ports[co->index].uart;
1532 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1533 unsigned int status, imr;
1534 unsigned int pdc_tx;
1535
1536 /*
1537 * First, save IMR and then disable interrupts
1538 */
1539 imr = UART_GET_IMR(port);
1540 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
1541
1542 /* Store PDC transmit status and disable it */
1543 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
1544 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1545
1546 uart_console_write(port, s, count, atmel_console_putchar);
1547
1548 /*
1549 * Finally, wait for transmitter to become empty
1550 * and restore IMR
1551 */
1552 do {
1553 status = UART_GET_CSR(port);
1554 } while (!(status & ATMEL_US_TXRDY));
1555
1556 /* Restore PDC transmit status */
1557 if (pdc_tx)
1558 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1559
1560 /* set interrupts back the way they were */
1561 UART_PUT_IER(port, imr);
1562 }
1563
1564 /*
1565 * If the port was already initialised (eg, by a boot loader),
1566 * try to determine the current setup.
1567 */
1568 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
1569 int *parity, int *bits)
1570 {
1571 unsigned int mr, quot;
1572
1573 /*
1574 * If the baud rate generator isn't running, the port wasn't
1575 * initialized by the boot loader.
1576 */
1577 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
1578 if (!quot)
1579 return;
1580
1581 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
1582 if (mr == ATMEL_US_CHRL_8)
1583 *bits = 8;
1584 else
1585 *bits = 7;
1586
1587 mr = UART_GET_MR(port) & ATMEL_US_PAR;
1588 if (mr == ATMEL_US_PAR_EVEN)
1589 *parity = 'e';
1590 else if (mr == ATMEL_US_PAR_ODD)
1591 *parity = 'o';
1592
1593 /*
1594 * The serial core only rounds down when matching this to a
1595 * supported baud rate. Make sure we don't end up slightly
1596 * lower than one of those, as it would make us fall through
1597 * to a much lower baud rate than we really want.
1598 */
1599 *baud = port->uartclk / (16 * (quot - 1));
1600 }
1601
1602 static int __init atmel_console_setup(struct console *co, char *options)
1603 {
1604 struct uart_port *port = &atmel_ports[co->index].uart;
1605 int baud = 115200;
1606 int bits = 8;
1607 int parity = 'n';
1608 int flow = 'n';
1609
1610 if (port->membase == NULL) {
1611 /* Port not initialized yet - delay setup */
1612 return -ENODEV;
1613 }
1614
1615 clk_enable(atmel_ports[co->index].clk);
1616
1617 UART_PUT_IDR(port, -1);
1618 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1619 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1620
1621 if (options)
1622 uart_parse_options(options, &baud, &parity, &bits, &flow);
1623 else
1624 atmel_console_get_options(port, &baud, &parity, &bits);
1625
1626 return uart_set_options(port, co, baud, parity, bits, flow);
1627 }
1628
1629 static struct uart_driver atmel_uart;
1630
1631 static struct console atmel_console = {
1632 .name = ATMEL_DEVICENAME,
1633 .write = atmel_console_write,
1634 .device = uart_console_device,
1635 .setup = atmel_console_setup,
1636 .flags = CON_PRINTBUFFER,
1637 .index = -1,
1638 .data = &atmel_uart,
1639 };
1640
1641 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
1642
1643 /*
1644 * Early console initialization (before VM subsystem initialized).
1645 */
1646 static int __init atmel_console_init(void)
1647 {
1648 if (atmel_default_console_device) {
1649 struct atmel_uart_data *pdata =
1650 atmel_default_console_device->dev.platform_data;
1651 int id = pdata->num;
1652 struct atmel_uart_port *port = &atmel_ports[id];
1653
1654 port->backup_imr = 0;
1655 port->uart.line = id;
1656
1657 add_preferred_console(ATMEL_DEVICENAME, id, NULL);
1658 atmel_init_port(port, atmel_default_console_device);
1659 register_console(&atmel_console);
1660 }
1661
1662 return 0;
1663 }
1664
1665 console_initcall(atmel_console_init);
1666
1667 /*
1668 * Late console initialization.
1669 */
1670 static int __init atmel_late_console_init(void)
1671 {
1672 if (atmel_default_console_device
1673 && !(atmel_console.flags & CON_ENABLED))
1674 register_console(&atmel_console);
1675
1676 return 0;
1677 }
1678
1679 core_initcall(atmel_late_console_init);
1680
1681 static inline bool atmel_is_console_port(struct uart_port *port)
1682 {
1683 return port->cons && port->cons->index == port->line;
1684 }
1685
1686 #else
1687 #define ATMEL_CONSOLE_DEVICE NULL
1688
1689 static inline bool atmel_is_console_port(struct uart_port *port)
1690 {
1691 return false;
1692 }
1693 #endif
1694
1695 static struct uart_driver atmel_uart = {
1696 .owner = THIS_MODULE,
1697 .driver_name = "atmel_serial",
1698 .dev_name = ATMEL_DEVICENAME,
1699 .major = SERIAL_ATMEL_MAJOR,
1700 .minor = MINOR_START,
1701 .nr = ATMEL_MAX_UART,
1702 .cons = ATMEL_CONSOLE_DEVICE,
1703 };
1704
1705 #ifdef CONFIG_PM
1706 static bool atmel_serial_clk_will_stop(void)
1707 {
1708 #ifdef CONFIG_ARCH_AT91
1709 return at91_suspend_entering_slow_clock();
1710 #else
1711 return false;
1712 #endif
1713 }
1714
1715 static int atmel_serial_suspend(struct platform_device *pdev,
1716 pm_message_t state)
1717 {
1718 struct uart_port *port = platform_get_drvdata(pdev);
1719 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1720
1721 if (atmel_is_console_port(port) && console_suspend_enabled) {
1722 /* Drain the TX shifter */
1723 while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
1724 cpu_relax();
1725 }
1726
1727 /* we can not wake up if we're running on slow clock */
1728 atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
1729 if (atmel_serial_clk_will_stop())
1730 device_set_wakeup_enable(&pdev->dev, 0);
1731
1732 uart_suspend_port(&atmel_uart, port);
1733
1734 return 0;
1735 }
1736
1737 static int atmel_serial_resume(struct platform_device *pdev)
1738 {
1739 struct uart_port *port = platform_get_drvdata(pdev);
1740 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1741
1742 uart_resume_port(&atmel_uart, port);
1743 device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
1744
1745 return 0;
1746 }
1747 #else
1748 #define atmel_serial_suspend NULL
1749 #define atmel_serial_resume NULL
1750 #endif
1751
1752 static int atmel_serial_probe(struct platform_device *pdev)
1753 {
1754 struct atmel_uart_port *port;
1755 struct device_node *np = pdev->dev.of_node;
1756 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1757 void *data;
1758 int ret = -ENODEV;
1759 struct pinctrl *pinctrl;
1760
1761 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
1762
1763 if (np)
1764 ret = of_alias_get_id(np, "serial");
1765 else
1766 if (pdata)
1767 ret = pdata->num;
1768
1769 if (ret < 0)
1770 /* port id not found in platform data nor device-tree aliases:
1771 * auto-enumerate it */
1772 ret = find_first_zero_bit(&atmel_ports_in_use,
1773 sizeof(atmel_ports_in_use));
1774
1775 if (ret > ATMEL_MAX_UART) {
1776 ret = -ENODEV;
1777 goto err;
1778 }
1779
1780 if (test_and_set_bit(ret, &atmel_ports_in_use)) {
1781 /* port already in use */
1782 ret = -EBUSY;
1783 goto err;
1784 }
1785
1786 port = &atmel_ports[ret];
1787 port->backup_imr = 0;
1788 port->uart.line = ret;
1789
1790 atmel_init_port(port, pdev);
1791
1792 pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
1793 if (IS_ERR(pinctrl)) {
1794 ret = PTR_ERR(pinctrl);
1795 goto err;
1796 }
1797
1798 if (!atmel_use_dma_rx(&port->uart)) {
1799 ret = -ENOMEM;
1800 data = kmalloc(sizeof(struct atmel_uart_char)
1801 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
1802 if (!data)
1803 goto err_alloc_ring;
1804 port->rx_ring.buf = data;
1805 }
1806
1807 ret = uart_add_one_port(&atmel_uart, &port->uart);
1808 if (ret)
1809 goto err_add_port;
1810
1811 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1812 if (atmel_is_console_port(&port->uart)
1813 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
1814 /*
1815 * The serial core enabled the clock for us, so undo
1816 * the clk_enable() in atmel_console_setup()
1817 */
1818 clk_disable(port->clk);
1819 }
1820 #endif
1821
1822 device_init_wakeup(&pdev->dev, 1);
1823 platform_set_drvdata(pdev, port);
1824
1825 if (port->rs485.flags & SER_RS485_ENABLED) {
1826 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
1827 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
1828 }
1829
1830 return 0;
1831
1832 err_add_port:
1833 kfree(port->rx_ring.buf);
1834 port->rx_ring.buf = NULL;
1835 err_alloc_ring:
1836 if (!atmel_is_console_port(&port->uart)) {
1837 clk_put(port->clk);
1838 port->clk = NULL;
1839 }
1840 err:
1841 return ret;
1842 }
1843
1844 static int atmel_serial_remove(struct platform_device *pdev)
1845 {
1846 struct uart_port *port = platform_get_drvdata(pdev);
1847 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1848 int ret = 0;
1849
1850 device_init_wakeup(&pdev->dev, 0);
1851 platform_set_drvdata(pdev, NULL);
1852
1853 ret = uart_remove_one_port(&atmel_uart, port);
1854
1855 tasklet_kill(&atmel_port->tasklet);
1856 kfree(atmel_port->rx_ring.buf);
1857
1858 /* "port" is allocated statically, so we shouldn't free it */
1859
1860 clear_bit(port->line, &atmel_ports_in_use);
1861
1862 clk_put(atmel_port->clk);
1863
1864 return ret;
1865 }
1866
1867 static struct platform_driver atmel_serial_driver = {
1868 .probe = atmel_serial_probe,
1869 .remove = atmel_serial_remove,
1870 .suspend = atmel_serial_suspend,
1871 .resume = atmel_serial_resume,
1872 .driver = {
1873 .name = "atmel_usart",
1874 .owner = THIS_MODULE,
1875 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
1876 },
1877 };
1878
1879 static int __init atmel_serial_init(void)
1880 {
1881 int ret;
1882
1883 ret = uart_register_driver(&atmel_uart);
1884 if (ret)
1885 return ret;
1886
1887 ret = platform_driver_register(&atmel_serial_driver);
1888 if (ret)
1889 uart_unregister_driver(&atmel_uart);
1890
1891 return ret;
1892 }
1893
1894 static void __exit atmel_serial_exit(void)
1895 {
1896 platform_driver_unregister(&atmel_serial_driver);
1897 uart_unregister_driver(&atmel_uart);
1898 }
1899
1900 module_init(atmel_serial_init);
1901 module_exit(atmel_serial_exit);
1902
1903 MODULE_AUTHOR("Rick Bronson");
1904 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
1905 MODULE_LICENSE("GPL");
1906 MODULE_ALIAS("platform:atmel_usart");
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