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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
51struct 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 */
74static struct uart_max3110 *pmax;
75
76static void receive_chars(struct uart_max3110 *max,
77 unsigned char *str, int len);
78static int max3110_read_multi(struct uart_max3110 *max, u8 *buf);
79static void max3110_con_receive(struct uart_max3110 *max);
80
81static 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 */
107static 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
134exit:
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 */
145static 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
183static 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 */
201static 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
213static int __init
214serial_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
238static 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
246static struct uart_driver serial_m3110_reg;
247static 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
257static unsigned int serial_m3110_tx_empty(struct uart_port *port)
258{
259 return 1;
260}
261
262static void serial_m3110_stop_tx(struct uart_port *port)
263{
264 return;
265}
266
267/* stop_rx will be called in spin_lock env */
268static void serial_m3110_stop_rx(struct uart_port *port)
269{
270 return;
271}
272
273#define WORDS_PER_XFER 128
274static 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
325static 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 */
346static 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
355static 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 */
391static 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
417static 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 pr_info(PR_FMT "start main thread\n");
425
426 do {
427 wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
428
429 mutex_lock(&max->thread_mutex);
430
431 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
432 max3110_con_receive(max);
433
434 /* first handle console output */
435 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
436 send_circ_buf(max, xmit);
437
438 /* handle uart output */
439 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
440 transmit_char(max);
441
442 mutex_unlock(&max->thread_mutex);
443
444 } while (!kthread_should_stop());
445
446 return ret;
447}
448
449static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
450{
451 struct uart_max3110 *max = dev_id;
452
453 /* max3110's irq is a falling edge, not level triggered,
454 * so no need to disable the irq */
455 if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
456 wake_up_process(max->main_thread);
457
458 return IRQ_HANDLED;
459}
460
461/* if don't use RX IRQ, then need a thread to polling read */
462static int max3110_read_thread(void *_max)
463{
464 struct uart_max3110 *max = _max;
465
466 pr_info(PR_FMT "start read thread\n");
467 do {
468 /*
469 * If can't acquire the mutex, it means the main thread
470 * is running which will also perform the rx job
471 */
472 if (mutex_trylock(&max->thread_mutex)) {
473 max3110_con_receive(max);
474 mutex_unlock(&max->thread_mutex);
475 }
476
477 set_current_state(TASK_INTERRUPTIBLE);
478 schedule_timeout(HZ / 20);
479 } while (!kthread_should_stop());
480
481 return 0;
482}
483
484static int serial_m3110_startup(struct uart_port *port)
485{
486 struct uart_max3110 *max =
487 container_of(port, struct uart_max3110, port);
488 u16 config = 0;
489 int ret = 0;
490
491 if (port->line != 0) {
492 pr_err(PR_FMT "uart port startup failed\n");
493 return -1;
494 }
495
496 /* Disable all IRQ and config it to 115200, 8n1 */
497 config = WC_TAG | WC_FIFO_ENABLE
498 | WC_1_STOPBITS
499 | WC_8BIT_WORD
500 | WC_BAUD_DR2;
501
502 /* as we use thread to handle tx/rx, need set low latency */
503 port->state->port.tty->low_latency = 1;
504
505 if (max->irq) {
506 max->read_thread = NULL;
507 ret = request_irq(max->irq, serial_m3110_irq,
508 IRQ_TYPE_EDGE_FALLING, "max3110", max);
509 if (ret) {
510 max->irq = 0;
511 pr_err(PR_FMT "unable to allocate IRQ, polling\n");
512 } else {
513 /* Enable RX IRQ only */
514 config |= WC_RXA_IRQ_ENABLE;
515 }
516 }
517
518 if (max->irq == 0) {
519 /* If IRQ is disabled, start a read thread for input data */
520 max->read_thread =
521 kthread_run(max3110_read_thread, max, "max3110_read");
522 if (IS_ERR(max->read_thread)) {
523 ret = PTR_ERR(max->read_thread);
524 max->read_thread = NULL;
525 pr_err(PR_FMT "Can't create read thread!\n");
526 return ret;
527 }
528 }
529
530 ret = max3110_out(max, config);
531 if (ret) {
532 if (max->irq)
533 free_irq(max->irq, max);
534 if (max->read_thread)
535 kthread_stop(max->read_thread);
536 max->read_thread = NULL;
537 return ret;
538 }
539
540 max->cur_conf = config;
541 return 0;
542}
543
544static void serial_m3110_shutdown(struct uart_port *port)
545{
546 struct uart_max3110 *max =
547 container_of(port, struct uart_max3110, port);
548 u16 config;
549
550 if (max->read_thread) {
551 kthread_stop(max->read_thread);
552 max->read_thread = NULL;
553 }
554
555 if (max->irq)
556 free_irq(max->irq, max);
557
558 /* Disable interrupts from this port */
559 config = WC_TAG | WC_SW_SHDI;
560 max3110_out(max, config);
561}
562
563static void serial_m3110_release_port(struct uart_port *port)
564{
565}
566
567static int serial_m3110_request_port(struct uart_port *port)
568{
569 return 0;
570}
571
572static void serial_m3110_config_port(struct uart_port *port, int flags)
573{
574 port->type = PORT_MAX3100;
575}
576
577static int
578serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
579{
580 /* we don't want the core code to modify any port params */
581 return -EINVAL;
582}
583
584
585static const char *serial_m3110_type(struct uart_port *port)
586{
587 struct uart_max3110 *max =
588 container_of(port, struct uart_max3110, port);
589 return max->name;
590}
591
592static void
593serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
594 struct ktermios *old)
595{
596 struct uart_max3110 *max =
597 container_of(port, struct uart_max3110, port);
598 unsigned char cval;
599 unsigned int baud, parity = 0;
600 int clk_div = -1;
601 u16 new_conf = max->cur_conf;
602
603 switch (termios->c_cflag & CSIZE) {
604 case CS7:
605 cval = UART_LCR_WLEN7;
606 new_conf |= WC_7BIT_WORD;
607 break;
608 default:
609 /* We only support CS7 & CS8 */
610 termios->c_cflag &= ~CSIZE;
611 termios->c_cflag |= CS8;
612 case CS8:
613 cval = UART_LCR_WLEN8;
614 new_conf |= WC_8BIT_WORD;
615 break;
616 }
617
618 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
619
620 /* First calc the div for 1.8MHZ clock case */
621 switch (baud) {
622 case 300:
623 clk_div = WC_BAUD_DR384;
624 break;
625 case 600:
626 clk_div = WC_BAUD_DR192;
627 break;
628 case 1200:
629 clk_div = WC_BAUD_DR96;
630 break;
631 case 2400:
632 clk_div = WC_BAUD_DR48;
633 break;
634 case 4800:
635 clk_div = WC_BAUD_DR24;
636 break;
637 case 9600:
638 clk_div = WC_BAUD_DR12;
639 break;
640 case 19200:
641 clk_div = WC_BAUD_DR6;
642 break;
643 case 38400:
644 clk_div = WC_BAUD_DR3;
645 break;
646 case 57600:
647 clk_div = WC_BAUD_DR2;
648 break;
649 case 115200:
650 clk_div = WC_BAUD_DR1;
651 break;
652 case 230400:
653 if (max->clock & MAX3110_HIGH_CLK)
654 break;
655 default:
656 /* Pick the previous baud rate */
657 baud = max->baud;
658 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
659 tty_termios_encode_baud_rate(termios, baud, baud);
660 }
661
662 if (max->clock & MAX3110_HIGH_CLK) {
663 clk_div += 1;
664 /* High clk version max3110 doesn't support B300 */
665 if (baud == 300) {
666 baud = 600;
667 clk_div = WC_BAUD_DR384;
668 }
669 if (baud == 230400)
670 clk_div = WC_BAUD_DR1;
671 tty_termios_encode_baud_rate(termios, baud, baud);
672 }
673
674 new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
675
676 if (unlikely(termios->c_cflag & CMSPAR))
677 termios->c_cflag &= ~CMSPAR;
678
679 if (termios->c_cflag & CSTOPB)
680 new_conf |= WC_2_STOPBITS;
681 else
682 new_conf &= ~WC_2_STOPBITS;
683
684 if (termios->c_cflag & PARENB) {
685 new_conf |= WC_PARITY_ENABLE;
686 parity |= UART_LCR_PARITY;
687 } else
688 new_conf &= ~WC_PARITY_ENABLE;
689
690 if (!(termios->c_cflag & PARODD))
691 parity |= UART_LCR_EPAR;
692 max->parity = parity;
693
694 uart_update_timeout(port, termios->c_cflag, baud);
695
696 new_conf |= WC_TAG;
697 if (new_conf != max->cur_conf) {
698 if (!max3110_out(max, new_conf)) {
699 max->cur_conf = new_conf;
700 max->baud = baud;
701 }
702 }
703}
704
705/* Don't handle hw handshaking */
706static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
707{
708 return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
709}
710
711static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
712{
713}
714
715static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
716{
717}
718
719static void serial_m3110_pm(struct uart_port *port, unsigned int state,
720 unsigned int oldstate)
721{
722}
723
724static void serial_m3110_enable_ms(struct uart_port *port)
725{
726}
727
728struct uart_ops serial_m3110_ops = {
729 .tx_empty = serial_m3110_tx_empty,
730 .set_mctrl = serial_m3110_set_mctrl,
731 .get_mctrl = serial_m3110_get_mctrl,
732 .stop_tx = serial_m3110_stop_tx,
733 .start_tx = serial_m3110_start_tx,
734 .stop_rx = serial_m3110_stop_rx,
735 .enable_ms = serial_m3110_enable_ms,
736 .break_ctl = serial_m3110_break_ctl,
737 .startup = serial_m3110_startup,
738 .shutdown = serial_m3110_shutdown,
739 .set_termios = serial_m3110_set_termios,
740 .pm = serial_m3110_pm,
741 .type = serial_m3110_type,
742 .release_port = serial_m3110_release_port,
743 .request_port = serial_m3110_request_port,
744 .config_port = serial_m3110_config_port,
745 .verify_port = serial_m3110_verify_port,
746};
747
748static struct uart_driver serial_m3110_reg = {
749 .owner = THIS_MODULE,
750 .driver_name = "MRST serial",
751 .dev_name = "ttyS",
752 .major = TTY_MAJOR,
753 .minor = 64,
754 .nr = 1,
755 .cons = &serial_m3110_console,
756};
757
758#ifdef CONFIG_PM
759static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
760{
761 struct uart_max3110 *max = spi_get_drvdata(spi);
762
763 disable_irq(max->irq);
764 uart_suspend_port(&serial_m3110_reg, &max->port);
765 max3110_out(max, max->cur_conf | WC_SW_SHDI);
766 return 0;
767}
768
769static int serial_m3110_resume(struct spi_device *spi)
770{
771 struct uart_max3110 *max = spi_get_drvdata(spi);
772
773 max3110_out(max, max->cur_conf);
774 uart_resume_port(&serial_m3110_reg, &max->port);
775 enable_irq(max->irq);
776 return 0;
777}
778#else
779#define serial_m3110_suspend NULL
780#define serial_m3110_resume NULL
781#endif
782
783static int __devinit serial_m3110_probe(struct spi_device *spi)
784{
785 struct uart_max3110 *max;
786 void *buffer;
787 u16 res;
788 int ret = 0;
789
790 max = kzalloc(sizeof(*max), GFP_KERNEL);
791 if (!max)
792 return -ENOMEM;
793
794 /* Set spi info */
795 spi->bits_per_word = 16;
796 max->clock = MAX3110_HIGH_CLK;
797
798 spi_setup(spi);
799
800 max->port.type = PORT_MAX3100;
801 max->port.fifosize = 2; /* Only have 16b buffer */
802 max->port.ops = &serial_m3110_ops;
803 max->port.line = 0;
804 max->port.dev = &spi->dev;
805 max->port.uartclk = 115200;
806
807 max->spi = spi;
808 strcpy(max->name, spi->modalias);
809 max->irq = (u16)spi->irq;
810
811 mutex_init(&max->thread_mutex);
812
813 max->word_7bits = 0;
814 max->parity = 0;
815 max->baud = 0;
816
817 max->cur_conf = 0;
818 max->uart_flags = 0;
819
820 /* Check if reading configuration register returns something sane */
821
822 res = RC_TAG;
823 ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
824 if (ret < 0 || res == 0 || res == 0xffff) {
825 dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
826 res);
827 ret = -ENODEV;
828 goto err_get_page;
829 }
830
831 buffer = (void *)__get_free_page(GFP_KERNEL);
832 if (!buffer) {
833 ret = -ENOMEM;
834 goto err_get_page;
835 }
836 max->con_xmit.buf = buffer;
837 max->con_xmit.head = 0;
838 max->con_xmit.tail = 0;
839
840 init_waitqueue_head(&max->wq);
841
842 max->main_thread = kthread_run(max3110_main_thread,
843 max, "max3110_main");
844 if (IS_ERR(max->main_thread)) {
845 ret = PTR_ERR(max->main_thread);
846 goto err_kthread;
847 }
848
849 spi_set_drvdata(spi, max);
850 pmax = max;
851
852 /* Give membase a psudo value to pass serial_core's check */
853 max->port.membase = (void *)0xff110000;
854 uart_add_one_port(&serial_m3110_reg, &max->port);
855
856 return 0;
857
858err_kthread:
859 free_page((unsigned long)buffer);
860err_get_page:
861 kfree(max);
862 return ret;
863}
864
865static int __devexit serial_m3110_remove(struct spi_device *dev)
866{
867 struct uart_max3110 *max = spi_get_drvdata(dev);
868
869 if (!max)
870 return 0;
871
872 uart_remove_one_port(&serial_m3110_reg, &max->port);
873
874 free_page((unsigned long)max->con_xmit.buf);
875
876 if (max->main_thread)
877 kthread_stop(max->main_thread);
878
879 kfree(max);
880 return 0;
881}
882
883static struct spi_driver uart_max3110_driver = {
884 .driver = {
885 .name = "spi_max3111",
886 .bus = &spi_bus_type,
887 .owner = THIS_MODULE,
888 },
889 .probe = serial_m3110_probe,
890 .remove = __devexit_p(serial_m3110_remove),
891 .suspend = serial_m3110_suspend,
892 .resume = serial_m3110_resume,
893};
894
895static int __init serial_m3110_init(void)
896{
897 int ret = 0;
898
899 ret = uart_register_driver(&serial_m3110_reg);
900 if (ret)
901 return ret;
902
903 ret = spi_register_driver(&uart_max3110_driver);
904 if (ret)
905 uart_unregister_driver(&serial_m3110_reg);
906
907 return ret;
908}
909
910static void __exit serial_m3110_exit(void)
911{
912 spi_unregister_driver(&uart_max3110_driver);
913 uart_unregister_driver(&serial_m3110_reg);
914}
915
916module_init(serial_m3110_init);
917module_exit(serial_m3110_exit);
918
919MODULE_LICENSE("GPL v2");
920MODULE_ALIAS("spi:max3110-uart");