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pch_uart: reference clock on CM-iTC
[linux/fpc-iii.git] / drivers / tty / serial / mrst_max3110.c
blob37e13c3d91d9970446f6ad66aaf96e3955dd33f3
1 /*
2 * mrst_max3110.c - spi uart protocol driver for Maxim 3110
3 *
4 * Copyright (c) 2008-2010, Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 /*
21 * Note:
22 * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has
23 * 1 word. If SPI master controller doesn't support sclk frequency change,
24 * then the char need be sent out one by one with some delay
25 *
26 * 2. Currently only RX availabe interrrupt is used, no need for waiting TXE
27 * interrupt for a low speed UART device
28 */
29
30 #include <linux/module.h>
31 #include <linux/ioport.h>
32 #include <linux/irq.h>
33 #include <linux/init.h>
34 #include <linux/console.h>
35 #include <linux/tty.h>
36 #include <linux/tty_flip.h>
37 #include <linux/serial_core.h>
38 #include <linux/serial_reg.h>
39
40 #include <linux/kthread.h>
41 #include <linux/spi/spi.h>
42
43 #include "mrst_max3110.h"
44
45 #define PR_FMT "mrst_max3110: "
46
47 #define UART_TX_NEEDED 1
48 #define CON_TX_NEEDED 2
49 #define BIT_IRQ_PENDING 3
50
51 struct uart_max3110 {
52 struct uart_port port;
53 struct spi_device *spi;
54 char name[SPI_NAME_SIZE];
55
56 wait_queue_head_t wq;
57 struct task_struct *main_thread;
58 struct task_struct *read_thread;
59 struct mutex thread_mutex;;
60
61 u32 baud;
62 u16 cur_conf;
63 u8 clock;
64 u8 parity, word_7bits;
65 u16 irq;
66
67 unsigned long uart_flags;
68
69 /* console related */
70 struct circ_buf con_xmit;
71 };
72
73 /* global data structure, may need be removed */
74 static struct uart_max3110 *pmax;
75
76 static void receive_chars(struct uart_max3110 *max,
77 unsigned char *str, int len);
78 static int max3110_read_multi(struct uart_max3110 *max, u8 *buf);
79 static void max3110_con_receive(struct uart_max3110 *max);
80
81 static int max3110_write_then_read(struct uart_max3110 *max,
82 const void *txbuf, void *rxbuf, unsigned len, int always_fast)
83 {
84 struct spi_device *spi = max->spi;
85 struct spi_message message;
86 struct spi_transfer x;
87 int ret;
88
89 spi_message_init(&message);
90 memset(&x, 0, sizeof x);
91 x.len = len;
92 x.tx_buf = txbuf;
93 x.rx_buf = rxbuf;
94 spi_message_add_tail(&x, &message);
95
96 if (always_fast)
97 x.speed_hz = spi->max_speed_hz;
98 else if (max->baud)
99 x.speed_hz = max->baud;
100
101 /* Do the i/o */
102 ret = spi_sync(spi, &message);
103 return ret;
104 }
105
106 /* Write a 16b word to the device */
107 static int max3110_out(struct uart_max3110 *max, const u16 out)
108 {
109 void *buf;
110 u16 *obuf, *ibuf;
111 u8 ch;
112 int ret;
113
114 buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
115 if (!buf)
116 return -ENOMEM;
117
118 obuf = buf;
119 ibuf = buf + 4;
120 *obuf = out;
121 ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
122 if (ret) {
123 pr_warning(PR_FMT "%s(): get err msg %d when sending 0x%x\n",
124 __func__, ret, out);
125 goto exit;
126 }
127
128 /* If some valid data is read back */
129 if (*ibuf & MAX3110_READ_DATA_AVAILABLE) {
130 ch = *ibuf & 0xff;
131 receive_chars(max, &ch, 1);
132 }
133
134 exit:
135 kfree(buf);
136 return ret;
137 }
138
139 /*
140 * This is usually used to read data from SPIC RX FIFO, which doesn't
141 * need any delay like flushing character out.
142 *
143 * Return how many valide bytes are read back
144 */
145 static int max3110_read_multi(struct uart_max3110 *max, u8 *rxbuf)
146 {
147 void *buf;
148 u16 *obuf, *ibuf;
149 u8 *pbuf, valid_str[M3110_RX_FIFO_DEPTH];
150 int i, j, blen;
151
152 blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
153 buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
154 if (!buf) {
155 pr_warning(PR_FMT "%s(): fail to alloc dma buffer\n", __func__);
156 return 0;
157 }
158
159 /* tx/rx always have the same length */
160 obuf = buf;
161 ibuf = buf + blen;
162
163 if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
164 kfree(buf);
165 return 0;
166 }
167
168 /* If caller doesn't provide a buffer, then handle received char */
169 pbuf = rxbuf ? rxbuf : valid_str;
170
171 for (i = 0, j = 0; i < M3110_RX_FIFO_DEPTH; i++) {
172 if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
173 pbuf[j++] = ibuf[i] & 0xff;
174 }
175
176 if (j && (pbuf == valid_str))
177 receive_chars(max, valid_str, j);
178
179 kfree(buf);
180 return j;
181 }
182
183 static void serial_m3110_con_putchar(struct uart_port *port, int ch)
184 {
185 struct uart_max3110 *max =
186 container_of(port, struct uart_max3110, port);
187 struct circ_buf *xmit = &max->con_xmit;
188
189 if (uart_circ_chars_free(xmit)) {
190 xmit->buf[xmit->head] = (char)ch;
191 xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
192 }
193 }
194
195 /*
196 * Print a string to the serial port trying not to disturb
197 * any possible real use of the port...
198 *
199 * The console_lock must be held when we get here.
200 */
201 static void serial_m3110_con_write(struct console *co,
202 const char *s, unsigned int count)
203 {
204 if (!pmax)
205 return;
206
207 uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
208
209 if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
210 wake_up_process(pmax->main_thread);
211 }
212
213 static int __init
214 serial_m3110_con_setup(struct console *co, char *options)
215 {
216 struct uart_max3110 *max = pmax;
217 int baud = 115200;
218 int bits = 8;
219 int parity = 'n';
220 int flow = 'n';
221
222 pr_info(PR_FMT "setting up console\n");
223
224 if (co->index == -1)
225 co->index = 0;
226
227 if (!max) {
228 pr_err(PR_FMT "pmax is NULL, return");
229 return -ENODEV;
230 }
231
232 if (options)
233 uart_parse_options(options, &baud, &parity, &bits, &flow);
234
235 return uart_set_options(&max->port, co, baud, parity, bits, flow);
236 }
237
238 static struct tty_driver *serial_m3110_con_device(struct console *co,
239 int *index)
240 {
241 struct uart_driver *p = co->data;
242 *index = co->index;
243 return p->tty_driver;
244 }
245
246 static struct uart_driver serial_m3110_reg;
247 static struct console serial_m3110_console = {
248 .name = "ttyS",
249 .write = serial_m3110_con_write,
250 .device = serial_m3110_con_device,
251 .setup = serial_m3110_con_setup,
252 .flags = CON_PRINTBUFFER,
253 .index = -1,
254 .data = &serial_m3110_reg,
255 };
256
257 static unsigned int serial_m3110_tx_empty(struct uart_port *port)
258 {
259 return 1;
260 }
261
262 static void serial_m3110_stop_tx(struct uart_port *port)
263 {
264 return;
265 }
266
267 /* stop_rx will be called in spin_lock env */
268 static void serial_m3110_stop_rx(struct uart_port *port)
269 {
270 return;
271 }
272
273 #define WORDS_PER_XFER 128
274 static void send_circ_buf(struct uart_max3110 *max,
275 struct circ_buf *xmit)
276 {
277 void *buf;
278 u16 *obuf, *ibuf;
279 u8 valid_str[WORDS_PER_XFER];
280 int i, j, len, blen, dma_size, left, ret = 0;
281
282
283 dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
284 buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
285 if (!buf)
286 return;
287 obuf = buf;
288 ibuf = buf + dma_size/2;
289
290 while (!uart_circ_empty(xmit)) {
291 left = uart_circ_chars_pending(xmit);
292 while (left) {
293 len = min(left, WORDS_PER_XFER);
294 blen = len * sizeof(u16);
295 memset(ibuf, 0, blen);
296
297 for (i = 0; i < len; i++) {
298 obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
299 xmit->tail = (xmit->tail + 1) &
300 (UART_XMIT_SIZE - 1);
301 }
302
303 /* Fail to send msg to console is not very critical */
304 ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
305 if (ret)
306 pr_warning(PR_FMT "%s(): get err msg %d\n",
307 __func__, ret);
308
309 for (i = 0, j = 0; i < len; i++) {
310 if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
311 valid_str[j++] = ibuf[i] & 0xff;
312 }
313
314 if (j)
315 receive_chars(max, valid_str, j);
316
317 max->port.icount.tx += len;
318 left -= len;
319 }
320 }
321
322 kfree(buf);
323 }
324
325 static void transmit_char(struct uart_max3110 *max)
326 {
327 struct uart_port *port = &max->port;
328 struct circ_buf *xmit = &port->state->xmit;
329
330 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
331 return;
332
333 send_circ_buf(max, xmit);
334
335 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
336 uart_write_wakeup(port);
337
338 if (uart_circ_empty(xmit))
339 serial_m3110_stop_tx(port);
340 }
341
342 /*
343 * This will be called by uart_write() and tty_write, can't
344 * go to sleep
345 */
346 static void serial_m3110_start_tx(struct uart_port *port)
347 {
348 struct uart_max3110 *max =
349 container_of(port, struct uart_max3110, port);
350
351 if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
352 wake_up_process(max->main_thread);
353 }
354
355 static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
356 {
357 struct uart_port *port = &max->port;
358 struct tty_struct *tty;
359 int usable;
360
361 /* If uart is not opened, just return */
362 if (!port->state)
363 return;
364
365 tty = port->state->port.tty;
366 if (!tty)
367 return;
368
369 while (len) {
370 usable = tty_buffer_request_room(tty, len);
371 if (usable) {
372 tty_insert_flip_string(tty, str, usable);
373 str += usable;
374 port->icount.rx += usable;
375 }
376 len -= usable;
377 }
378 tty_flip_buffer_push(tty);
379 }
380
381 /*
382 * This routine will be used in read_thread or RX IRQ handling,
383 * it will first do one round buffer read(8 words), if there is some
384 * valid RX data, will try to read 5 more rounds till all data
385 * is read out.
386 *
387 * Use stack space as data buffer to save some system load, and chose
388 * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
389 * receiving bulk data, a much bigger buffer may cause stack overflow
390 */
391 static void max3110_con_receive(struct uart_max3110 *max)
392 {
393 int loop = 1, num, total = 0;
394 u8 recv_buf[512], *pbuf;
395
396 pbuf = recv_buf;
397 do {
398 num = max3110_read_multi(max, pbuf);
399
400 if (num) {
401 loop = 5;
402 pbuf += num;
403 total += num;
404
405 if (total >= 504) {
406 receive_chars(max, recv_buf, total);
407 pbuf = recv_buf;
408 total = 0;
409 }
410 }
411 } while (--loop);
412
413 if (total)
414 receive_chars(max, recv_buf, total);
415 }
416
417 static int max3110_main_thread(void *_max)
418 {
419 struct uart_max3110 *max = _max;
420 wait_queue_head_t *wq = &max->wq;
421 int ret = 0;
422 struct circ_buf *xmit = &max->con_xmit;
423
424 init_waitqueue_head(wq);
425 pr_info(PR_FMT "start main thread\n");
426
427 do {
428 wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
429
430 mutex_lock(&max->thread_mutex);
431
432 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
433 max3110_con_receive(max);
434
435 /* first handle console output */
436 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
437 send_circ_buf(max, xmit);
438
439 /* handle uart output */
440 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
441 transmit_char(max);
442
443 mutex_unlock(&max->thread_mutex);
444
445 } while (!kthread_should_stop());
446
447 return ret;
448 }
449
450 static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
451 {
452 struct uart_max3110 *max = dev_id;
453
454 /* max3110's irq is a falling edge, not level triggered,
455 * so no need to disable the irq */
456 if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
457 wake_up_process(max->main_thread);
458
459 return IRQ_HANDLED;
460 }
461
462 /* if don't use RX IRQ, then need a thread to polling read */
463 static int max3110_read_thread(void *_max)
464 {
465 struct uart_max3110 *max = _max;
466
467 pr_info(PR_FMT "start read thread\n");
468 do {
469 /*
470 * If can't acquire the mutex, it means the main thread
471 * is running which will also perform the rx job
472 */
473 if (mutex_trylock(&max->thread_mutex)) {
474 max3110_con_receive(max);
475 mutex_unlock(&max->thread_mutex);
476 }
477
478 set_current_state(TASK_INTERRUPTIBLE);
479 schedule_timeout(HZ / 20);
480 } while (!kthread_should_stop());
481
482 return 0;
483 }
484
485 static int serial_m3110_startup(struct uart_port *port)
486 {
487 struct uart_max3110 *max =
488 container_of(port, struct uart_max3110, port);
489 u16 config = 0;
490 int ret = 0;
491
492 if (port->line != 0) {
493 pr_err(PR_FMT "uart port startup failed\n");
494 return -1;
495 }
496
497 /* Disable all IRQ and config it to 115200, 8n1 */
498 config = WC_TAG | WC_FIFO_ENABLE
499 | WC_1_STOPBITS
500 | WC_8BIT_WORD
501 | WC_BAUD_DR2;
502
503 /* as we use thread to handle tx/rx, need set low latency */
504 port->state->port.tty->low_latency = 1;
505
506 if (max->irq) {
507 max->read_thread = NULL;
508 ret = request_irq(max->irq, serial_m3110_irq,
509 IRQ_TYPE_EDGE_FALLING, "max3110", max);
510 if (ret) {
511 max->irq = 0;
512 pr_err(PR_FMT "unable to allocate IRQ, polling\n");
513 } else {
514 /* Enable RX IRQ only */
515 config |= WC_RXA_IRQ_ENABLE;
516 }
517 }
518
519 if (max->irq == 0) {
520 /* If IRQ is disabled, start a read thread for input data */
521 max->read_thread =
522 kthread_run(max3110_read_thread, max, "max3110_read");
523 if (IS_ERR(max->read_thread)) {
524 ret = PTR_ERR(max->read_thread);
525 max->read_thread = NULL;
526 pr_err(PR_FMT "Can't create read thread!\n");
527 return ret;
528 }
529 }
530
531 ret = max3110_out(max, config);
532 if (ret) {
533 if (max->irq)
534 free_irq(max->irq, max);
535 if (max->read_thread)
536 kthread_stop(max->read_thread);
537 max->read_thread = NULL;
538 return ret;
539 }
540
541 max->cur_conf = config;
542 return 0;
543 }
544
545 static void serial_m3110_shutdown(struct uart_port *port)
546 {
547 struct uart_max3110 *max =
548 container_of(port, struct uart_max3110, port);
549 u16 config;
550
551 if (max->read_thread) {
552 kthread_stop(max->read_thread);
553 max->read_thread = NULL;
554 }
555
556 if (max->irq)
557 free_irq(max->irq, max);
558
559 /* Disable interrupts from this port */
560 config = WC_TAG | WC_SW_SHDI;
561 max3110_out(max, config);
562 }
563
564 static void serial_m3110_release_port(struct uart_port *port)
565 {
566 }
567
568 static int serial_m3110_request_port(struct uart_port *port)
569 {
570 return 0;
571 }
572
573 static void serial_m3110_config_port(struct uart_port *port, int flags)
574 {
575 port->type = PORT_MAX3100;
576 }
577
578 static int
579 serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
580 {
581 /* we don't want the core code to modify any port params */
582 return -EINVAL;
583 }
584
585
586 static const char *serial_m3110_type(struct uart_port *port)
587 {
588 struct uart_max3110 *max =
589 container_of(port, struct uart_max3110, port);
590 return max->name;
591 }
592
593 static void
594 serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
595 struct ktermios *old)
596 {
597 struct uart_max3110 *max =
598 container_of(port, struct uart_max3110, port);
599 unsigned char cval;
600 unsigned int baud, parity = 0;
601 int clk_div = -1;
602 u16 new_conf = max->cur_conf;
603
604 switch (termios->c_cflag & CSIZE) {
605 case CS7:
606 cval = UART_LCR_WLEN7;
607 new_conf |= WC_7BIT_WORD;
608 break;
609 default:
610 /* We only support CS7 & CS8 */
611 termios->c_cflag &= ~CSIZE;
612 termios->c_cflag |= CS8;
613 case CS8:
614 cval = UART_LCR_WLEN8;
615 new_conf |= WC_8BIT_WORD;
616 break;
617 }
618
619 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
620
621 /* First calc the div for 1.8MHZ clock case */
622 switch (baud) {
623 case 300:
624 clk_div = WC_BAUD_DR384;
625 break;
626 case 600:
627 clk_div = WC_BAUD_DR192;
628 break;
629 case 1200:
630 clk_div = WC_BAUD_DR96;
631 break;
632 case 2400:
633 clk_div = WC_BAUD_DR48;
634 break;
635 case 4800:
636 clk_div = WC_BAUD_DR24;
637 break;
638 case 9600:
639 clk_div = WC_BAUD_DR12;
640 break;
641 case 19200:
642 clk_div = WC_BAUD_DR6;
643 break;
644 case 38400:
645 clk_div = WC_BAUD_DR3;
646 break;
647 case 57600:
648 clk_div = WC_BAUD_DR2;
649 break;
650 case 115200:
651 clk_div = WC_BAUD_DR1;
652 break;
653 case 230400:
654 if (max->clock & MAX3110_HIGH_CLK)
655 break;
656 default:
657 /* Pick the previous baud rate */
658 baud = max->baud;
659 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
660 tty_termios_encode_baud_rate(termios, baud, baud);
661 }
662
663 if (max->clock & MAX3110_HIGH_CLK) {
664 clk_div += 1;
665 /* High clk version max3110 doesn't support B300 */
666 if (baud == 300) {
667 baud = 600;
668 clk_div = WC_BAUD_DR384;
669 }
670 if (baud == 230400)
671 clk_div = WC_BAUD_DR1;
672 tty_termios_encode_baud_rate(termios, baud, baud);
673 }
674
675 new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
676
677 if (unlikely(termios->c_cflag & CMSPAR))
678 termios->c_cflag &= ~CMSPAR;
679
680 if (termios->c_cflag & CSTOPB)
681 new_conf |= WC_2_STOPBITS;
682 else
683 new_conf &= ~WC_2_STOPBITS;
684
685 if (termios->c_cflag & PARENB) {
686 new_conf |= WC_PARITY_ENABLE;
687 parity |= UART_LCR_PARITY;
688 } else
689 new_conf &= ~WC_PARITY_ENABLE;
690
691 if (!(termios->c_cflag & PARODD))
692 parity |= UART_LCR_EPAR;
693 max->parity = parity;
694
695 uart_update_timeout(port, termios->c_cflag, baud);
696
697 new_conf |= WC_TAG;
698 if (new_conf != max->cur_conf) {
699 if (!max3110_out(max, new_conf)) {
700 max->cur_conf = new_conf;
701 max->baud = baud;
702 }
703 }
704 }
705
706 /* Don't handle hw handshaking */
707 static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
708 {
709 return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
710 }
711
712 static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
713 {
714 }
715
716 static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
717 {
718 }
719
720 static void serial_m3110_pm(struct uart_port *port, unsigned int state,
721 unsigned int oldstate)
722 {
723 }
724
725 static void serial_m3110_enable_ms(struct uart_port *port)
726 {
727 }
728
729 struct uart_ops serial_m3110_ops = {
730 .tx_empty = serial_m3110_tx_empty,
731 .set_mctrl = serial_m3110_set_mctrl,
732 .get_mctrl = serial_m3110_get_mctrl,
733 .stop_tx = serial_m3110_stop_tx,
734 .start_tx = serial_m3110_start_tx,
735 .stop_rx = serial_m3110_stop_rx,
736 .enable_ms = serial_m3110_enable_ms,
737 .break_ctl = serial_m3110_break_ctl,
738 .startup = serial_m3110_startup,
739 .shutdown = serial_m3110_shutdown,
740 .set_termios = serial_m3110_set_termios,
741 .pm = serial_m3110_pm,
742 .type = serial_m3110_type,
743 .release_port = serial_m3110_release_port,
744 .request_port = serial_m3110_request_port,
745 .config_port = serial_m3110_config_port,
746 .verify_port = serial_m3110_verify_port,
747 };
748
749 static struct uart_driver serial_m3110_reg = {
750 .owner = THIS_MODULE,
751 .driver_name = "MRST serial",
752 .dev_name = "ttyS",
753 .major = TTY_MAJOR,
754 .minor = 64,
755 .nr = 1,
756 .cons = &serial_m3110_console,
757 };
758
759 #ifdef CONFIG_PM
760 static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
761 {
762 struct uart_max3110 *max = spi_get_drvdata(spi);
763
764 disable_irq(max->irq);
765 uart_suspend_port(&serial_m3110_reg, &max->port);
766 max3110_out(max, max->cur_conf | WC_SW_SHDI);
767 return 0;
768 }
769
770 static int serial_m3110_resume(struct spi_device *spi)
771 {
772 struct uart_max3110 *max = spi_get_drvdata(spi);
773
774 max3110_out(max, max->cur_conf);
775 uart_resume_port(&serial_m3110_reg, &max->port);
776 enable_irq(max->irq);
777 return 0;
778 }
779 #else
780 #define serial_m3110_suspend NULL
781 #define serial_m3110_resume NULL
782 #endif
783
784 static int __devinit serial_m3110_probe(struct spi_device *spi)
785 {
786 struct uart_max3110 *max;
787 void *buffer;
788 u16 res;
789 int ret = 0;
790
791 max = kzalloc(sizeof(*max), GFP_KERNEL);
792 if (!max)
793 return -ENOMEM;
794
795 /* Set spi info */
796 spi->bits_per_word = 16;
797 max->clock = MAX3110_HIGH_CLK;
798
799 spi_setup(spi);
800
801 max->port.type = PORT_MAX3100;
802 max->port.fifosize = 2; /* Only have 16b buffer */
803 max->port.ops = &serial_m3110_ops;
804 max->port.line = 0;
805 max->port.dev = &spi->dev;
806 max->port.uartclk = 115200;
807
808 max->spi = spi;
809 strcpy(max->name, spi->modalias);
810 max->irq = (u16)spi->irq;
811
812 mutex_init(&max->thread_mutex);
813
814 max->word_7bits = 0;
815 max->parity = 0;
816 max->baud = 0;
817
818 max->cur_conf = 0;
819 max->uart_flags = 0;
820
821 /* Check if reading configuration register returns something sane */
822
823 res = RC_TAG;
824 ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
825 if (ret < 0 || res == 0 || res == 0xffff) {
826 printk(KERN_ERR "MAX3111 deemed not present (conf reg %04x)",
827 res);
828 ret = -ENODEV;
829 goto err_get_page;
830 }
831
832 buffer = (void *)__get_free_page(GFP_KERNEL);
833 if (!buffer) {
834 ret = -ENOMEM;
835 goto err_get_page;
836 }
837 max->con_xmit.buf = buffer;
838 max->con_xmit.head = 0;
839 max->con_xmit.tail = 0;
840
841 max->main_thread = kthread_run(max3110_main_thread,
842 max, "max3110_main");
843 if (IS_ERR(max->main_thread)) {
844 ret = PTR_ERR(max->main_thread);
845 goto err_kthread;
846 }
847
848 spi_set_drvdata(spi, max);
849 pmax = max;
850
851 /* Give membase a psudo value to pass serial_core's check */
852 max->port.membase = (void *)0xff110000;
853 uart_add_one_port(&serial_m3110_reg, &max->port);
854
855 return 0;
856
857 err_kthread:
858 free_page((unsigned long)buffer);
859 err_get_page:
860 kfree(max);
861 return ret;
862 }
863
864 static int __devexit serial_m3110_remove(struct spi_device *dev)
865 {
866 struct uart_max3110 *max = spi_get_drvdata(dev);
867
868 if (!max)
869 return 0;
870
871 uart_remove_one_port(&serial_m3110_reg, &max->port);
872
873 free_page((unsigned long)max->con_xmit.buf);
874
875 if (max->main_thread)
876 kthread_stop(max->main_thread);
877
878 kfree(max);
879 return 0;
880 }
881
882 static struct spi_driver uart_max3110_driver = {
883 .driver = {
884 .name = "spi_max3111",
885 .bus = &spi_bus_type,
886 .owner = THIS_MODULE,
887 },
888 .probe = serial_m3110_probe,
889 .remove = __devexit_p(serial_m3110_remove),
890 .suspend = serial_m3110_suspend,
891 .resume = serial_m3110_resume,
892 };
893
894 static int __init serial_m3110_init(void)
895 {
896 int ret = 0;
897
898 ret = uart_register_driver(&serial_m3110_reg);
899 if (ret)
900 return ret;
901
902 ret = spi_register_driver(&uart_max3110_driver);
903 if (ret)
904 uart_unregister_driver(&serial_m3110_reg);
905
906 return ret;
907 }
908
909 static void __exit serial_m3110_exit(void)
910 {
911 spi_unregister_driver(&uart_max3110_driver);
912 uart_unregister_driver(&serial_m3110_reg);
913 }
914
915 module_init(serial_m3110_init);
916 module_exit(serial_m3110_exit);
917
918 MODULE_LICENSE("GPL v2");
919 MODULE_ALIAS("max3110-uart");
Linux with added FPC-III support