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max3110: wake up fixes
[linux-2.6.git] / drivers / tty / serial / mrst_max3110.c
blobc8f986876229b9626fb841fe51300b38a5cae13b
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 available 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(&pmax->wq);
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
305 ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
306 if (ret)
307 pr_warning(PR_FMT "%s(): get err msg %d\n",
308 __func__, ret);
309
310 for (i = 0, j = 0; i < len; i++) {
311 if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
312 valid_str[j++] = ibuf[i] & 0xff;
313 }
314
315 if (j)
316 receive_chars(max, valid_str, j);
317
318 max->port.icount.tx += len;
319 left -= len;
320 }
321 }
322
323 kfree(buf);
324 }
325
326 static void transmit_char(struct uart_max3110 *max)
327 {
328 struct uart_port *port = &max->port;
329 struct circ_buf *xmit = &port->state->xmit;
330
331 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
332 return;
333
334 send_circ_buf(max, xmit);
335
336 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
337 uart_write_wakeup(port);
338
339 if (uart_circ_empty(xmit))
340 serial_m3110_stop_tx(port);
341 }
342
343 /*
344 * This will be called by uart_write() and tty_write, can't
345 * go to sleep
346 */
347 static void serial_m3110_start_tx(struct uart_port *port)
348 {
349 struct uart_max3110 *max =
350 container_of(port, struct uart_max3110, port);
351
352 if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
353 wake_up(&max->wq);
354 }
355
356 static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
357 {
358 struct uart_port *port = &max->port;
359 struct tty_struct *tty;
360 int usable;
361
362 /* If uart is not opened, just return */
363 if (!port->state)
364 return;
365
366 tty = port->state->port.tty;
367 if (!tty)
368 return;
369
370 while (len) {
371 usable = tty_buffer_request_room(tty, len);
372 if (usable) {
373 tty_insert_flip_string(tty, str, usable);
374 str += usable;
375 port->icount.rx += usable;
376 }
377 len -= usable;
378 }
379 tty_flip_buffer_push(tty);
380 }
381
382 /*
383 * This routine will be used in read_thread or RX IRQ handling,
384 * it will first do one round buffer read(8 words), if there is some
385 * valid RX data, will try to read 5 more rounds till all data
386 * is read out.
387 *
388 * Use stack space as data buffer to save some system load, and chose
389 * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
390 * receiving bulk data, a much bigger buffer may cause stack overflow
391 */
392 static void max3110_con_receive(struct uart_max3110 *max)
393 {
394 int loop = 1, num, total = 0;
395 u8 recv_buf[512], *pbuf;
396
397 pbuf = recv_buf;
398 do {
399 num = max3110_read_multi(max, pbuf);
400
401 if (num) {
402 loop = 5;
403 pbuf += num;
404 total += num;
405
406 if (total >= 504) {
407 receive_chars(max, recv_buf, total);
408 pbuf = recv_buf;
409 total = 0;
410 }
411 }
412 } while (--loop);
413
414 if (total)
415 receive_chars(max, recv_buf, total);
416 }
417
418 static int max3110_main_thread(void *_max)
419 {
420 struct uart_max3110 *max = _max;
421 wait_queue_head_t *wq = &max->wq;
422 int ret = 0;
423 struct circ_buf *xmit = &max->con_xmit;
424
425 pr_info(PR_FMT "start main thread\n");
426
427 do {
428 wait_event_interruptible(*wq,
429 max->uart_flags || kthread_should_stop());
430
431 mutex_lock(&max->thread_mutex);
432
433 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
434 max3110_con_receive(max);
435
436 /* first handle console output */
437 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
438 send_circ_buf(max, xmit);
439
440 /* handle uart output */
441 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
442 transmit_char(max);
443
444 mutex_unlock(&max->thread_mutex);
445
446 } while (!kthread_should_stop());
447
448 return ret;
449 }
450
451 static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
452 {
453 struct uart_max3110 *max = dev_id;
454
455 /* max3110's irq is a falling edge, not level triggered,
456 * so no need to disable the irq */
457
458 if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
459 wake_up(&max->wq);
460
461 return IRQ_HANDLED;
462 }
463
464 /* if don't use RX IRQ, then need a thread to polling read */
465 static int max3110_read_thread(void *_max)
466 {
467 struct uart_max3110 *max = _max;
468
469 pr_info(PR_FMT "start read thread\n");
470 do {
471 /*
472 * If can't acquire the mutex, it means the main thread
473 * is running which will also perform the rx job
474 */
475 if (mutex_trylock(&max->thread_mutex)) {
476 max3110_con_receive(max);
477 mutex_unlock(&max->thread_mutex);
478 }
479
480 set_current_state(TASK_INTERRUPTIBLE);
481 schedule_timeout(HZ / 20);
482 } while (!kthread_should_stop());
483
484 return 0;
485 }
486
487 static int serial_m3110_startup(struct uart_port *port)
488 {
489 struct uart_max3110 *max =
490 container_of(port, struct uart_max3110, port);
491 u16 config = 0;
492 int ret = 0;
493
494 if (port->line != 0) {
495 pr_err(PR_FMT "uart port startup failed\n");
496 return -1;
497 }
498
499 /* Disable all IRQ and config it to 115200, 8n1 */
500 config = WC_TAG | WC_FIFO_ENABLE
501 | WC_1_STOPBITS
502 | WC_8BIT_WORD
503 | WC_BAUD_DR2;
504
505 /* as we use thread to handle tx/rx, need set low latency */
506 port->state->port.tty->low_latency = 1;
507
508 if (max->irq) {
509 max->read_thread = NULL;
510 ret = request_irq(max->irq, serial_m3110_irq,
511 IRQ_TYPE_EDGE_FALLING, "max3110", max);
512 if (ret) {
513 max->irq = 0;
514 pr_err(PR_FMT "unable to allocate IRQ, polling\n");
515 } else {
516 /* Enable RX IRQ only */
517 config |= WC_RXA_IRQ_ENABLE;
518 }
519 }
520
521 if (max->irq == 0) {
522 /* If IRQ is disabled, start a read thread for input data */
523 max->read_thread =
524 kthread_run(max3110_read_thread, max, "max3110_read");
525 if (IS_ERR(max->read_thread)) {
526 ret = PTR_ERR(max->read_thread);
527 max->read_thread = NULL;
528 pr_err(PR_FMT "Can't create read thread!\n");
529 return ret;
530 }
531 }
532
533 ret = max3110_out(max, config);
534 if (ret) {
535 if (max->irq)
536 free_irq(max->irq, max);
537 if (max->read_thread)
538 kthread_stop(max->read_thread);
539 max->read_thread = NULL;
540 return ret;
541 }
542
543 max->cur_conf = config;
544 return 0;
545 }
546
547 static void serial_m3110_shutdown(struct uart_port *port)
548 {
549 struct uart_max3110 *max =
550 container_of(port, struct uart_max3110, port);
551 u16 config;
552
553 if (max->read_thread) {
554 kthread_stop(max->read_thread);
555 max->read_thread = NULL;
556 }
557
558 if (max->irq)
559 free_irq(max->irq, max);
560
561 /* Disable interrupts from this port */
562 config = WC_TAG | WC_SW_SHDI;
563 max3110_out(max, config);
564 }
565
566 static void serial_m3110_release_port(struct uart_port *port)
567 {
568 }
569
570 static int serial_m3110_request_port(struct uart_port *port)
571 {
572 return 0;
573 }
574
575 static void serial_m3110_config_port(struct uart_port *port, int flags)
576 {
577 port->type = PORT_MAX3100;
578 }
579
580 static int
581 serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
582 {
583 /* we don't want the core code to modify any port params */
584 return -EINVAL;
585 }
586
587
588 static const char *serial_m3110_type(struct uart_port *port)
589 {
590 struct uart_max3110 *max =
591 container_of(port, struct uart_max3110, port);
592 return max->name;
593 }
594
595 static void
596 serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
597 struct ktermios *old)
598 {
599 struct uart_max3110 *max =
600 container_of(port, struct uart_max3110, port);
601 unsigned char cval;
602 unsigned int baud, parity = 0;
603 int clk_div = -1;
604 u16 new_conf = max->cur_conf;
605
606 switch (termios->c_cflag & CSIZE) {
607 case CS7:
608 cval = UART_LCR_WLEN7;
609 new_conf |= WC_7BIT_WORD;
610 break;
611 default:
612 /* We only support CS7 & CS8 */
613 termios->c_cflag &= ~CSIZE;
614 termios->c_cflag |= CS8;
615 case CS8:
616 cval = UART_LCR_WLEN8;
617 new_conf |= WC_8BIT_WORD;
618 break;
619 }
620
621 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
622
623 /* First calc the div for 1.8MHZ clock case */
624 switch (baud) {
625 case 300:
626 clk_div = WC_BAUD_DR384;
627 break;
628 case 600:
629 clk_div = WC_BAUD_DR192;
630 break;
631 case 1200:
632 clk_div = WC_BAUD_DR96;
633 break;
634 case 2400:
635 clk_div = WC_BAUD_DR48;
636 break;
637 case 4800:
638 clk_div = WC_BAUD_DR24;
639 break;
640 case 9600:
641 clk_div = WC_BAUD_DR12;
642 break;
643 case 19200:
644 clk_div = WC_BAUD_DR6;
645 break;
646 case 38400:
647 clk_div = WC_BAUD_DR3;
648 break;
649 case 57600:
650 clk_div = WC_BAUD_DR2;
651 break;
652 case 115200:
653 clk_div = WC_BAUD_DR1;
654 break;
655 case 230400:
656 if (max->clock & MAX3110_HIGH_CLK)
657 break;
658 default:
659 /* Pick the previous baud rate */
660 baud = max->baud;
661 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
662 tty_termios_encode_baud_rate(termios, baud, baud);
663 }
664
665 if (max->clock & MAX3110_HIGH_CLK) {
666 clk_div += 1;
667 /* High clk version max3110 doesn't support B300 */
668 if (baud == 300) {
669 baud = 600;
670 clk_div = WC_BAUD_DR384;
671 }
672 if (baud == 230400)
673 clk_div = WC_BAUD_DR1;
674 tty_termios_encode_baud_rate(termios, baud, baud);
675 }
676
677 new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
678
679 if (unlikely(termios->c_cflag & CMSPAR))
680 termios->c_cflag &= ~CMSPAR;
681
682 if (termios->c_cflag & CSTOPB)
683 new_conf |= WC_2_STOPBITS;
684 else
685 new_conf &= ~WC_2_STOPBITS;
686
687 if (termios->c_cflag & PARENB) {
688 new_conf |= WC_PARITY_ENABLE;
689 parity |= UART_LCR_PARITY;
690 } else
691 new_conf &= ~WC_PARITY_ENABLE;
692
693 if (!(termios->c_cflag & PARODD))
694 parity |= UART_LCR_EPAR;
695 max->parity = parity;
696
697 uart_update_timeout(port, termios->c_cflag, baud);
698
699 new_conf |= WC_TAG;
700 if (new_conf != max->cur_conf) {
701 if (!max3110_out(max, new_conf)) {
702 max->cur_conf = new_conf;
703 max->baud = baud;
704 }
705 }
706 }
707
708 /* Don't handle hw handshaking */
709 static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
710 {
711 return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
712 }
713
714 static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
715 {
716 }
717
718 static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
719 {
720 }
721
722 static void serial_m3110_pm(struct uart_port *port, unsigned int state,
723 unsigned int oldstate)
724 {
725 }
726
727 static void serial_m3110_enable_ms(struct uart_port *port)
728 {
729 }
730
731 struct uart_ops serial_m3110_ops = {
732 .tx_empty = serial_m3110_tx_empty,
733 .set_mctrl = serial_m3110_set_mctrl,
734 .get_mctrl = serial_m3110_get_mctrl,
735 .stop_tx = serial_m3110_stop_tx,
736 .start_tx = serial_m3110_start_tx,
737 .stop_rx = serial_m3110_stop_rx,
738 .enable_ms = serial_m3110_enable_ms,
739 .break_ctl = serial_m3110_break_ctl,
740 .startup = serial_m3110_startup,
741 .shutdown = serial_m3110_shutdown,
742 .set_termios = serial_m3110_set_termios,
743 .pm = serial_m3110_pm,
744 .type = serial_m3110_type,
745 .release_port = serial_m3110_release_port,
746 .request_port = serial_m3110_request_port,
747 .config_port = serial_m3110_config_port,
748 .verify_port = serial_m3110_verify_port,
749 };
750
751 static struct uart_driver serial_m3110_reg = {
752 .owner = THIS_MODULE,
753 .driver_name = "MRST serial",
754 .dev_name = "ttyS",
755 .major = TTY_MAJOR,
756 .minor = 64,
757 .nr = 1,
758 .cons = &serial_m3110_console,
759 };
760
761 #ifdef CONFIG_PM
762 static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
763 {
764 struct uart_max3110 *max = spi_get_drvdata(spi);
765
766 disable_irq(max->irq);
767 uart_suspend_port(&serial_m3110_reg, &max->port);
768 max3110_out(max, max->cur_conf | WC_SW_SHDI);
769 return 0;
770 }
771
772 static int serial_m3110_resume(struct spi_device *spi)
773 {
774 struct uart_max3110 *max = spi_get_drvdata(spi);
775
776 max3110_out(max, max->cur_conf);
777 uart_resume_port(&serial_m3110_reg, &max->port);
778 enable_irq(max->irq);
779 return 0;
780 }
781 #else
782 #define serial_m3110_suspend NULL
783 #define serial_m3110_resume NULL
784 #endif
785
786 static int __devinit serial_m3110_probe(struct spi_device *spi)
787 {
788 struct uart_max3110 *max;
789 void *buffer;
790 u16 res;
791 int ret = 0;
792
793 max = kzalloc(sizeof(*max), GFP_KERNEL);
794 if (!max)
795 return -ENOMEM;
796
797 /* Set spi info */
798 spi->bits_per_word = 16;
799 max->clock = MAX3110_HIGH_CLK;
800
801 spi_setup(spi);
802
803 max->port.type = PORT_MAX3100;
804 max->port.fifosize = 2; /* Only have 16b buffer */
805 max->port.ops = &serial_m3110_ops;
806 max->port.line = 0;
807 max->port.dev = &spi->dev;
808 max->port.uartclk = 115200;
809
810 max->spi = spi;
811 strcpy(max->name, spi->modalias);
812 max->irq = (u16)spi->irq;
813
814 mutex_init(&max->thread_mutex);
815
816 max->word_7bits = 0;
817 max->parity = 0;
818 max->baud = 0;
819
820 max->cur_conf = 0;
821 max->uart_flags = 0;
822
823 /* Check if reading configuration register returns something sane */
824
825 res = RC_TAG;
826 ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
827 if (ret < 0 || res == 0 || res == 0xffff) {
828 dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
829 res);
830 ret = -ENODEV;
831 goto err_get_page;
832 }
833
834 buffer = (void *)__get_free_page(GFP_KERNEL);
835 if (!buffer) {
836 ret = -ENOMEM;
837 goto err_get_page;
838 }
839 max->con_xmit.buf = buffer;
840 max->con_xmit.head = 0;
841 max->con_xmit.tail = 0;
842
843 init_waitqueue_head(&max->wq);
844
845 max->main_thread = kthread_run(max3110_main_thread,
846 max, "max3110_main");
847 if (IS_ERR(max->main_thread)) {
848 ret = PTR_ERR(max->main_thread);
849 goto err_kthread;
850 }
851
852 spi_set_drvdata(spi, max);
853 pmax = max;
854
855 /* Give membase a psudo value to pass serial_core's check */
856 max->port.membase = (void *)0xff110000;
857 uart_add_one_port(&serial_m3110_reg, &max->port);
858
859 return 0;
860
861 err_kthread:
862 free_page((unsigned long)buffer);
863 err_get_page:
864 kfree(max);
865 return ret;
866 }
867
868 static int __devexit serial_m3110_remove(struct spi_device *dev)
869 {
870 struct uart_max3110 *max = spi_get_drvdata(dev);
871
872 if (!max)
873 return 0;
874
875 uart_remove_one_port(&serial_m3110_reg, &max->port);
876
877 free_page((unsigned long)max->con_xmit.buf);
878
879 if (max->main_thread)
880 kthread_stop(max->main_thread);
881
882 kfree(max);
883 return 0;
884 }
885
886 static struct spi_driver uart_max3110_driver = {
887 .driver = {
888 .name = "spi_max3111",
889 .bus = &spi_bus_type,
890 .owner = THIS_MODULE,
891 },
892 .probe = serial_m3110_probe,
893 .remove = __devexit_p(serial_m3110_remove),
894 .suspend = serial_m3110_suspend,
895 .resume = serial_m3110_resume,
896 };
897
898 static int __init serial_m3110_init(void)
899 {
900 int ret = 0;
901
902 ret = uart_register_driver(&serial_m3110_reg);
903 if (ret)
904 return ret;
905
906 ret = spi_register_driver(&uart_max3110_driver);
907 if (ret)
908 uart_unregister_driver(&serial_m3110_reg);
909
910 return ret;
911 }
912
913 static void __exit serial_m3110_exit(void)
914 {
915 spi_unregister_driver(&uart_max3110_driver);
916 uart_unregister_driver(&serial_m3110_reg);
917 }
918
919 module_init(serial_m3110_init);
920 module_exit(serial_m3110_exit);
921
922 MODULE_LICENSE("GPL v2");
923 MODULE_ALIAS("max3110-uart");
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