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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 interrupt is used, no need for waiting TXE
27 * interrupt for a low speed UART device
28 */
29
30#ifdef CONFIG_MAGIC_SYSRQ
31#define SUPPORT_SYSRQ
32#endif
33
34#include <linux/module.h>
35#include <linux/ioport.h>
36#include <linux/irq.h>
37#include <linux/init.h>
38#include <linux/console.h>
39#include <linux/tty.h>
40#include <linux/tty_flip.h>
41#include <linux/serial_core.h>
42#include <linux/serial_reg.h>
43
44#include <linux/kthread.h>
45#include <linux/spi/spi.h>
46
47#include "mrst_max3110.h"
48
49#define PR_FMT "mrst_max3110: "
50
51#define UART_TX_NEEDED 1
52#define CON_TX_NEEDED 2
53#define BIT_IRQ_PENDING 3
54
55struct uart_max3110 {
56 struct uart_port port;
57 struct spi_device *spi;
58 char name[SPI_NAME_SIZE];
59
60 wait_queue_head_t wq;
61 struct task_struct *main_thread;
62 struct task_struct *read_thread;
63 struct mutex thread_mutex;
64
65 u32 baud;
66 u16 cur_conf;
67 u8 clock;
68 u8 parity, word_7bits;
69 u16 irq;
70
71 unsigned long uart_flags;
72
73 /* console related */
74 struct circ_buf con_xmit;
75};
76
77/* global data structure, may need be removed */
78static struct uart_max3110 *pmax;
79
80static int receive_chars(struct uart_max3110 *max,
81 unsigned short *str, int len);
82static int max3110_read_multi(struct uart_max3110 *max);
83static void max3110_con_receive(struct uart_max3110 *max);
84
85static int max3110_write_then_read(struct uart_max3110 *max,
86 const void *txbuf, void *rxbuf, unsigned len, int always_fast)
87{
88 struct spi_device *spi = max->spi;
89 struct spi_message message;
90 struct spi_transfer x;
91 int ret;
92
93 spi_message_init(&message);
94 memset(&x, 0, sizeof x);
95 x.len = len;
96 x.tx_buf = txbuf;
97 x.rx_buf = rxbuf;
98 spi_message_add_tail(&x, &message);
99
100 if (always_fast)
101 x.speed_hz = spi->max_speed_hz;
102 else if (max->baud)
103 x.speed_hz = max->baud;
104
105 /* Do the i/o */
106 ret = spi_sync(spi, &message);
107 return ret;
108}
109
110/* Write a 16b word to the device */
111static int max3110_out(struct uart_max3110 *max, const u16 out)
112{
113 void *buf;
114 u16 *obuf, *ibuf;
115 int ret;
116
117 buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
118 if (!buf)
119 return -ENOMEM;
120
121 obuf = buf;
122 ibuf = buf + 4;
123 *obuf = out;
124 ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
125 if (ret) {
126 pr_warning(PR_FMT "%s(): get err msg %d when sending 0x%x\n",
127 __func__, ret, out);
128 goto exit;
129 }
130
131 receive_chars(max, ibuf, 1);
132
133exit:
134 kfree(buf);
135 return ret;
136}
137
138/*
139 * This is usually used to read data from SPIC RX FIFO, which doesn't
140 * need any delay like flushing character out.
141 *
142 * Return how many valide bytes are read back
143 */
144static int max3110_read_multi(struct uart_max3110 *max)
145{
146 void *buf;
147 u16 *obuf, *ibuf;
148 int ret, blen;
149
150 blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
151 buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
152 if (!buf) {
153 pr_warning(PR_FMT "%s(): fail to alloc dma buffer\n", __func__);
154 return 0;
155 }
156
157 /* tx/rx always have the same length */
158 obuf = buf;
159 ibuf = buf + blen;
160
161 if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
162 kfree(buf);
163 return 0;
164 }
165
166 ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH);
167
168 kfree(buf);
169 return ret;
170}
171
172static void serial_m3110_con_putchar(struct uart_port *port, int ch)
173{
174 struct uart_max3110 *max =
175 container_of(port, struct uart_max3110, port);
176 struct circ_buf *xmit = &max->con_xmit;
177
178 if (uart_circ_chars_free(xmit)) {
179 xmit->buf[xmit->head] = (char)ch;
180 xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
181 }
182}
183
184/*
185 * Print a string to the serial port trying not to disturb
186 * any possible real use of the port...
187 *
188 * The console_lock must be held when we get here.
189 */
190static void serial_m3110_con_write(struct console *co,
191 const char *s, unsigned int count)
192{
193 if (!pmax)
194 return;
195
196 uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
197
198 if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
199 wake_up(&pmax->wq);
200}
201
202static int __init
203serial_m3110_con_setup(struct console *co, char *options)
204{
205 struct uart_max3110 *max = pmax;
206 int baud = 115200;
207 int bits = 8;
208 int parity = 'n';
209 int flow = 'n';
210
211 pr_info(PR_FMT "setting up console\n");
212
213 if (co->index == -1)
214 co->index = 0;
215
216 if (!max) {
217 pr_err(PR_FMT "pmax is NULL, return");
218 return -ENODEV;
219 }
220
221 if (options)
222 uart_parse_options(options, &baud, &parity, &bits, &flow);
223
224 return uart_set_options(&max->port, co, baud, parity, bits, flow);
225}
226
227static struct tty_driver *serial_m3110_con_device(struct console *co,
228 int *index)
229{
230 struct uart_driver *p = co->data;
231 *index = co->index;
232 return p->tty_driver;
233}
234
235static struct uart_driver serial_m3110_reg;
236static struct console serial_m3110_console = {
237 .name = "ttyS",
238 .write = serial_m3110_con_write,
239 .device = serial_m3110_con_device,
240 .setup = serial_m3110_con_setup,
241 .flags = CON_PRINTBUFFER,
242 .index = -1,
243 .data = &serial_m3110_reg,
244};
245
246static unsigned int serial_m3110_tx_empty(struct uart_port *port)
247{
248 return 1;
249}
250
251static void serial_m3110_stop_tx(struct uart_port *port)
252{
253 return;
254}
255
256/* stop_rx will be called in spin_lock env */
257static void serial_m3110_stop_rx(struct uart_port *port)
258{
259 return;
260}
261
262#define WORDS_PER_XFER 128
263static void send_circ_buf(struct uart_max3110 *max,
264 struct circ_buf *xmit)
265{
266 void *buf;
267 u16 *obuf, *ibuf;
268 int i, len, blen, dma_size, left, ret = 0;
269
270
271 dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
272 buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
273 if (!buf)
274 return;
275 obuf = buf;
276 ibuf = buf + dma_size/2;
277
278 while (!uart_circ_empty(xmit)) {
279 left = uart_circ_chars_pending(xmit);
280 while (left) {
281 len = min(left, WORDS_PER_XFER);
282 blen = len * sizeof(u16);
283 memset(ibuf, 0, blen);
284
285 for (i = 0; i < len; i++) {
286 obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
287 xmit->tail = (xmit->tail + 1) &
288 (UART_XMIT_SIZE - 1);
289 }
290
291 /* Fail to send msg to console is not very critical */
292
293 ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
294 if (ret)
295 pr_warning(PR_FMT "%s(): get err msg %d\n",
296 __func__, ret);
297
298 receive_chars(max, ibuf, len);
299
300 max->port.icount.tx += len;
301 left -= len;
302 }
303 }
304
305 kfree(buf);
306}
307
308static void transmit_char(struct uart_max3110 *max)
309{
310 struct uart_port *port = &max->port;
311 struct circ_buf *xmit = &port->state->xmit;
312
313 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
314 return;
315
316 send_circ_buf(max, xmit);
317
318 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
319 uart_write_wakeup(port);
320
321 if (uart_circ_empty(xmit))
322 serial_m3110_stop_tx(port);
323}
324
325/*
326 * This will be called by uart_write() and tty_write, can't
327 * go to sleep
328 */
329static void serial_m3110_start_tx(struct uart_port *port)
330{
331 struct uart_max3110 *max =
332 container_of(port, struct uart_max3110, port);
333
334 if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
335 wake_up(&max->wq);
336}
337
338static int
339receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
340{
341 struct uart_port *port = &max->port;
342 struct tty_struct *tty;
343 char buf[M3110_RX_FIFO_DEPTH];
344 int r, w, usable;
345
346 /* If uart is not opened, just return */
347 if (!port->state)
348 return 0;
349
350 tty = tty_port_tty_get(&port->state->port);
351 if (!tty)
352 return 0;
353
354 for (r = 0, w = 0; r < len; r++) {
355 if (str[r] & MAX3110_BREAK &&
356 uart_handle_break(port))
357 continue;
358
359 if (str[r] & MAX3110_READ_DATA_AVAILABLE) {
360 if (uart_handle_sysrq_char(port, str[r] & 0xff))
361 continue;
362
363 buf[w++] = str[r] & 0xff;
364 }
365 }
366
367 if (!w) {
368 tty_kref_put(tty);
369 return 0;
370 }
371
372 for (r = 0; w; r += usable, w -= usable) {
373 usable = tty_buffer_request_room(tty, w);
374 if (usable) {
375 tty_insert_flip_string(tty, buf + r, usable);
376 port->icount.rx += usable;
377 }
378 }
379 tty_flip_buffer_push(tty);
380 tty_kref_put(tty);
381
382 return r;
383}
384
385/*
386 * This routine will be used in read_thread or RX IRQ handling,
387 * it will first do one round buffer read(8 words), if there is some
388 * valid RX data, will try to read 5 more rounds till all data
389 * is read out.
390 *
391 * Use stack space as data buffer to save some system load, and chose
392 * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
393 * receiving bulk data, a much bigger buffer may cause stack overflow
394 */
395static void max3110_con_receive(struct uart_max3110 *max)
396{
397 int loop = 1, num;
398
399 do {
400 num = max3110_read_multi(max);
401
402 if (num) {
403 loop = 5;
404 }
405 } while (--loop);
406}
407
408static int max3110_main_thread(void *_max)
409{
410 struct uart_max3110 *max = _max;
411 wait_queue_head_t *wq = &max->wq;
412 int ret = 0;
413 struct circ_buf *xmit = &max->con_xmit;
414
415 pr_info(PR_FMT "start main thread\n");
416
417 do {
418 wait_event_interruptible(*wq,
419 max->uart_flags || kthread_should_stop());
420
421 mutex_lock(&max->thread_mutex);
422
423 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
424 max3110_con_receive(max);
425
426 /* first handle console output */
427 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
428 send_circ_buf(max, xmit);
429
430 /* handle uart output */
431 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
432 transmit_char(max);
433
434 mutex_unlock(&max->thread_mutex);
435
436 } while (!kthread_should_stop());
437
438 return ret;
439}
440
441static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
442{
443 struct uart_max3110 *max = dev_id;
444
445 /* max3110's irq is a falling edge, not level triggered,
446 * so no need to disable the irq */
447
448 if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
449 wake_up(&max->wq);
450
451 return IRQ_HANDLED;
452}
453
454/* if don't use RX IRQ, then need a thread to polling read */
455static int max3110_read_thread(void *_max)
456{
457 struct uart_max3110 *max = _max;
458
459 pr_info(PR_FMT "start read thread\n");
460 do {
461 /*
462 * If can't acquire the mutex, it means the main thread
463 * is running which will also perform the rx job
464 */
465 if (mutex_trylock(&max->thread_mutex)) {
466 max3110_con_receive(max);
467 mutex_unlock(&max->thread_mutex);
468 }
469
470 set_current_state(TASK_INTERRUPTIBLE);
471 schedule_timeout(HZ / 20);
472 } while (!kthread_should_stop());
473
474 return 0;
475}
476
477static int serial_m3110_startup(struct uart_port *port)
478{
479 struct uart_max3110 *max =
480 container_of(port, struct uart_max3110, port);
481 u16 config = 0;
482 int ret = 0;
483
484 if (port->line != 0) {
485 pr_err(PR_FMT "uart port startup failed\n");
486 return -1;
487 }
488
489 /* Disable all IRQ and config it to 115200, 8n1 */
490 config = WC_TAG | WC_FIFO_ENABLE
491 | WC_1_STOPBITS
492 | WC_8BIT_WORD
493 | WC_BAUD_DR2;
494
495 /* as we use thread to handle tx/rx, need set low latency */
496 port->state->port.tty->low_latency = 1;
497
498 if (max->irq) {
499 max->read_thread = NULL;
500 ret = request_irq(max->irq, serial_m3110_irq,
501 IRQ_TYPE_EDGE_FALLING, "max3110", max);
502 if (ret) {
503 max->irq = 0;
504 pr_err(PR_FMT "unable to allocate IRQ, polling\n");
505 } else {
506 /* Enable RX IRQ only */
507 config |= WC_RXA_IRQ_ENABLE;
508 }
509 }
510
511 if (max->irq == 0) {
512 /* If IRQ is disabled, start a read thread for input data */
513 max->read_thread =
514 kthread_run(max3110_read_thread, max, "max3110_read");
515 if (IS_ERR(max->read_thread)) {
516 ret = PTR_ERR(max->read_thread);
517 max->read_thread = NULL;
518 pr_err(PR_FMT "Can't create read thread!\n");
519 return ret;
520 }
521 }
522
523 ret = max3110_out(max, config);
524 if (ret) {
525 if (max->irq)
526 free_irq(max->irq, max);
527 if (max->read_thread)
528 kthread_stop(max->read_thread);
529 max->read_thread = NULL;
530 return ret;
531 }
532
533 max->cur_conf = config;
534 return 0;
535}
536
537static void serial_m3110_shutdown(struct uart_port *port)
538{
539 struct uart_max3110 *max =
540 container_of(port, struct uart_max3110, port);
541 u16 config;
542
543 if (max->read_thread) {
544 kthread_stop(max->read_thread);
545 max->read_thread = NULL;
546 }
547
548 if (max->irq)
549 free_irq(max->irq, max);
550
551 /* Disable interrupts from this port */
552 config = WC_TAG | WC_SW_SHDI;
553 max3110_out(max, config);
554}
555
556static void serial_m3110_release_port(struct uart_port *port)
557{
558}
559
560static int serial_m3110_request_port(struct uart_port *port)
561{
562 return 0;
563}
564
565static void serial_m3110_config_port(struct uart_port *port, int flags)
566{
567 port->type = PORT_MAX3100;
568}
569
570static int
571serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
572{
573 /* we don't want the core code to modify any port params */
574 return -EINVAL;
575}
576
577
578static const char *serial_m3110_type(struct uart_port *port)
579{
580 struct uart_max3110 *max =
581 container_of(port, struct uart_max3110, port);
582 return max->name;
583}
584
585static void
586serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
587 struct ktermios *old)
588{
589 struct uart_max3110 *max =
590 container_of(port, struct uart_max3110, port);
591 unsigned char cval;
592 unsigned int baud, parity = 0;
593 int clk_div = -1;
594 u16 new_conf = max->cur_conf;
595
596 switch (termios->c_cflag & CSIZE) {
597 case CS7:
598 cval = UART_LCR_WLEN7;
599 new_conf |= WC_7BIT_WORD;
600 break;
601 default:
602 /* We only support CS7 & CS8 */
603 termios->c_cflag &= ~CSIZE;
604 termios->c_cflag |= CS8;
605 case CS8:
606 cval = UART_LCR_WLEN8;
607 new_conf |= WC_8BIT_WORD;
608 break;
609 }
610
611 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
612
613 /* First calc the div for 1.8MHZ clock case */
614 switch (baud) {
615 case 300:
616 clk_div = WC_BAUD_DR384;
617 break;
618 case 600:
619 clk_div = WC_BAUD_DR192;
620 break;
621 case 1200:
622 clk_div = WC_BAUD_DR96;
623 break;
624 case 2400:
625 clk_div = WC_BAUD_DR48;
626 break;
627 case 4800:
628 clk_div = WC_BAUD_DR24;
629 break;
630 case 9600:
631 clk_div = WC_BAUD_DR12;
632 break;
633 case 19200:
634 clk_div = WC_BAUD_DR6;
635 break;
636 case 38400:
637 clk_div = WC_BAUD_DR3;
638 break;
639 case 57600:
640 clk_div = WC_BAUD_DR2;
641 break;
642 case 115200:
643 clk_div = WC_BAUD_DR1;
644 break;
645 case 230400:
646 if (max->clock & MAX3110_HIGH_CLK)
647 break;
648 default:
649 /* Pick the previous baud rate */
650 baud = max->baud;
651 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
652 tty_termios_encode_baud_rate(termios, baud, baud);
653 }
654
655 if (max->clock & MAX3110_HIGH_CLK) {
656 clk_div += 1;
657 /* High clk version max3110 doesn't support B300 */
658 if (baud == 300) {
659 baud = 600;
660 clk_div = WC_BAUD_DR384;
661 }
662 if (baud == 230400)
663 clk_div = WC_BAUD_DR1;
664 tty_termios_encode_baud_rate(termios, baud, baud);
665 }
666
667 new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
668
669 if (unlikely(termios->c_cflag & CMSPAR))
670 termios->c_cflag &= ~CMSPAR;
671
672 if (termios->c_cflag & CSTOPB)
673 new_conf |= WC_2_STOPBITS;
674 else
675 new_conf &= ~WC_2_STOPBITS;
676
677 if (termios->c_cflag & PARENB) {
678 new_conf |= WC_PARITY_ENABLE;
679 parity |= UART_LCR_PARITY;
680 } else
681 new_conf &= ~WC_PARITY_ENABLE;
682
683 if (!(termios->c_cflag & PARODD))
684 parity |= UART_LCR_EPAR;
685 max->parity = parity;
686
687 uart_update_timeout(port, termios->c_cflag, baud);
688
689 new_conf |= WC_TAG;
690 if (new_conf != max->cur_conf) {
691 if (!max3110_out(max, new_conf)) {
692 max->cur_conf = new_conf;
693 max->baud = baud;
694 }
695 }
696}
697
698/* Don't handle hw handshaking */
699static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
700{
701 return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
702}
703
704static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
705{
706}
707
708static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
709{
710}
711
712static void serial_m3110_pm(struct uart_port *port, unsigned int state,
713 unsigned int oldstate)
714{
715}
716
717static void serial_m3110_enable_ms(struct uart_port *port)
718{
719}
720
721struct uart_ops serial_m3110_ops = {
722 .tx_empty = serial_m3110_tx_empty,
723 .set_mctrl = serial_m3110_set_mctrl,
724 .get_mctrl = serial_m3110_get_mctrl,
725 .stop_tx = serial_m3110_stop_tx,
726 .start_tx = serial_m3110_start_tx,
727 .stop_rx = serial_m3110_stop_rx,
728 .enable_ms = serial_m3110_enable_ms,
729 .break_ctl = serial_m3110_break_ctl,
730 .startup = serial_m3110_startup,
731 .shutdown = serial_m3110_shutdown,
732 .set_termios = serial_m3110_set_termios,
733 .pm = serial_m3110_pm,
734 .type = serial_m3110_type,
735 .release_port = serial_m3110_release_port,
736 .request_port = serial_m3110_request_port,
737 .config_port = serial_m3110_config_port,
738 .verify_port = serial_m3110_verify_port,
739};
740
741static struct uart_driver serial_m3110_reg = {
742 .owner = THIS_MODULE,
743 .driver_name = "MRST serial",
744 .dev_name = "ttyS",
745 .major = TTY_MAJOR,
746 .minor = 64,
747 .nr = 1,
748 .cons = &serial_m3110_console,
749};
750
751#ifdef CONFIG_PM
752static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
753{
754 struct uart_max3110 *max = spi_get_drvdata(spi);
755
756 disable_irq(max->irq);
757 uart_suspend_port(&serial_m3110_reg, &max->port);
758 max3110_out(max, max->cur_conf | WC_SW_SHDI);
759 return 0;
760}
761
762static int serial_m3110_resume(struct spi_device *spi)
763{
764 struct uart_max3110 *max = spi_get_drvdata(spi);
765
766 max3110_out(max, max->cur_conf);
767 uart_resume_port(&serial_m3110_reg, &max->port);
768 enable_irq(max->irq);
769 return 0;
770}
771#else
772#define serial_m3110_suspend NULL
773#define serial_m3110_resume NULL
774#endif
775
776static int __devinit serial_m3110_probe(struct spi_device *spi)
777{
778 struct uart_max3110 *max;
779 void *buffer;
780 u16 res;
781 int ret = 0;
782
783 max = kzalloc(sizeof(*max), GFP_KERNEL);
784 if (!max)
785 return -ENOMEM;
786
787 /* Set spi info */
788 spi->bits_per_word = 16;
789 max->clock = MAX3110_HIGH_CLK;
790
791 spi_setup(spi);
792
793 max->port.type = PORT_MAX3100;
794 max->port.fifosize = 2; /* Only have 16b buffer */
795 max->port.ops = &serial_m3110_ops;
796 max->port.line = 0;
797 max->port.dev = &spi->dev;
798 max->port.uartclk = 115200;
799
800 max->spi = spi;
801 strcpy(max->name, spi->modalias);
802 max->irq = (u16)spi->irq;
803
804 mutex_init(&max->thread_mutex);
805
806 max->word_7bits = 0;
807 max->parity = 0;
808 max->baud = 0;
809
810 max->cur_conf = 0;
811 max->uart_flags = 0;
812
813 /* Check if reading configuration register returns something sane */
814
815 res = RC_TAG;
816 ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
817 if (ret < 0 || res == 0 || res == 0xffff) {
818 dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
819 res);
820 ret = -ENODEV;
821 goto err_get_page;
822 }
823
824 buffer = (void *)__get_free_page(GFP_KERNEL);
825 if (!buffer) {
826 ret = -ENOMEM;
827 goto err_get_page;
828 }
829 max->con_xmit.buf = buffer;
830 max->con_xmit.head = 0;
831 max->con_xmit.tail = 0;
832
833 init_waitqueue_head(&max->wq);
834
835 max->main_thread = kthread_run(max3110_main_thread,
836 max, "max3110_main");
837 if (IS_ERR(max->main_thread)) {
838 ret = PTR_ERR(max->main_thread);
839 goto err_kthread;
840 }
841
842 spi_set_drvdata(spi, max);
843 pmax = max;
844
845 /* Give membase a psudo value to pass serial_core's check */
846 max->port.membase = (void *)0xff110000;
847 uart_add_one_port(&serial_m3110_reg, &max->port);
848
849 return 0;
850
851err_kthread:
852 free_page((unsigned long)buffer);
853err_get_page:
854 kfree(max);
855 return ret;
856}
857
858static int __devexit serial_m3110_remove(struct spi_device *dev)
859{
860 struct uart_max3110 *max = spi_get_drvdata(dev);
861
862 if (!max)
863 return 0;
864
865 uart_remove_one_port(&serial_m3110_reg, &max->port);
866
867 free_page((unsigned long)max->con_xmit.buf);
868
869 if (max->main_thread)
870 kthread_stop(max->main_thread);
871
872 kfree(max);
873 return 0;
874}
875
876static struct spi_driver uart_max3110_driver = {
877 .driver = {
878 .name = "spi_max3111",
879 .owner = THIS_MODULE,
880 },
881 .probe = serial_m3110_probe,
882 .remove = __devexit_p(serial_m3110_remove),
883 .suspend = serial_m3110_suspend,
884 .resume = serial_m3110_resume,
885};
886
887static int __init serial_m3110_init(void)
888{
889 int ret = 0;
890
891 ret = uart_register_driver(&serial_m3110_reg);
892 if (ret)
893 return ret;
894
895 ret = spi_register_driver(&uart_max3110_driver);
896 if (ret)
897 uart_unregister_driver(&serial_m3110_reg);
898
899 return ret;
900}
901
902static void __exit serial_m3110_exit(void)
903{
904 spi_unregister_driver(&uart_max3110_driver);
905 uart_unregister_driver(&serial_m3110_reg);
906}
907
908module_init(serial_m3110_init);
909module_exit(serial_m3110_exit);
910
911MODULE_LICENSE("GPL v2");
912MODULE_ALIAS("spi:max3110-uart");