1 /*
2 * SPI bus via the Blackfin SPORT peripheral
3 *
4 * Enter bugs at http://blackfin.uclinux.org/
5 *
6 * Copyright 2009-2011 Analog Devices Inc.
7 *
8 * Licensed under the GPL-2 or later.
9 */
10
11 #include <linux/module.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/gpio.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/irq.h>
18 #include <linux/errno.h>
19 #include <linux/interrupt.h>
20 #include <linux/platform_device.h>
21 #include <linux/spi/spi.h>
22 #include <linux/workqueue.h>
23
24 #include <asm/portmux.h>
25 #include <asm/bfin5xx_spi.h>
26 #include <asm/blackfin.h>
27 #include <asm/bfin_sport.h>
28 #include <asm/cacheflush.h>
29
30 #define DRV_NAME "bfin-sport-spi"
31 #define DRV_DESC "SPI bus via the Blackfin SPORT"
32
33 MODULE_AUTHOR("Cliff Cai");
34 MODULE_DESCRIPTION(DRV_DESC);
35 MODULE_LICENSE("GPL");
36 MODULE_ALIAS("platform:bfin-sport-spi");
37
38 enum bfin_sport_spi_state {
39 START_STATE,
40 RUNNING_STATE,
41 DONE_STATE,
42 ERROR_STATE,
43 };
44
45 struct bfin_sport_spi_master_data;
46
47 struct bfin_sport_transfer_ops {
48 void (*write) (struct bfin_sport_spi_master_data *);
49 void (*read) (struct bfin_sport_spi_master_data *);
50 void (*duplex) (struct bfin_sport_spi_master_data *);
51 };
52
53 struct bfin_sport_spi_master_data {
54 /* Driver model hookup */
55 struct device *dev;
56
57 /* SPI framework hookup */
58 struct spi_master *master;
59
60 /* Regs base of SPI controller */
61 struct sport_register __iomem *regs;
62 int err_irq;
63
64 /* Pin request list */
65 u16 *pin_req;
66
67 /* Driver message queue */
68 struct workqueue_struct *workqueue;
69 struct work_struct pump_messages;
70 spinlock_t lock;
71 struct list_head queue;
72 int busy;
73 bool run;
74
75 /* Message Transfer pump */
76 struct tasklet_struct pump_transfers;
77
78 /* Current message transfer state info */
79 enum bfin_sport_spi_state state;
80 struct spi_message *cur_msg;
81 struct spi_transfer *cur_transfer;
82 struct bfin_sport_spi_slave_data *cur_chip;
83 union {
84 void *tx;
85 u8 *tx8;
86 u16 *tx16;
87 };
88 void *tx_end;
89 union {
90 void *rx;
91 u8 *rx8;
92 u16 *rx16;
93 };
94 void *rx_end;
95
96 int cs_change;
97 struct bfin_sport_transfer_ops *ops;
98 };
99
100 struct bfin_sport_spi_slave_data {
101 u16 ctl_reg;
102 u16 baud;
103 u16 cs_chg_udelay; /* Some devices require > 255usec delay */
104 u32 cs_gpio;
105 u16 idle_tx_val;
106 struct bfin_sport_transfer_ops *ops;
107 };
108
109 static void
bfin_sport_spi_enable(struct bfin_sport_spi_master_data * drv_data)110 bfin_sport_spi_enable(struct bfin_sport_spi_master_data *drv_data)
111 {
112 bfin_write_or(&drv_data->regs->tcr1, TSPEN);
113 bfin_write_or(&drv_data->regs->rcr1, TSPEN);
114 SSYNC();
115 }
116
117 static void
bfin_sport_spi_disable(struct bfin_sport_spi_master_data * drv_data)118 bfin_sport_spi_disable(struct bfin_sport_spi_master_data *drv_data)
119 {
120 bfin_write_and(&drv_data->regs->tcr1, ~TSPEN);
121 bfin_write_and(&drv_data->regs->rcr1, ~TSPEN);
122 SSYNC();
123 }
124
125 /* Caculate the SPI_BAUD register value based on input HZ */
126 static u16
bfin_sport_hz_to_spi_baud(u32 speed_hz)127 bfin_sport_hz_to_spi_baud(u32 speed_hz)
128 {
129 u_long clk, sclk = get_sclk();
130 int div = (sclk / (2 * speed_hz)) - 1;
131
132 if (div < 0)
133 div = 0;
134
135 clk = sclk / (2 * (div + 1));
136
137 if (clk > speed_hz)
138 div++;
139
140 return div;
141 }
142
143 /* Chip select operation functions for cs_change flag */
144 static void
bfin_sport_spi_cs_active(struct bfin_sport_spi_slave_data * chip)145 bfin_sport_spi_cs_active(struct bfin_sport_spi_slave_data *chip)
146 {
147 gpio_direction_output(chip->cs_gpio, 0);
148 }
149
150 static void
bfin_sport_spi_cs_deactive(struct bfin_sport_spi_slave_data * chip)151 bfin_sport_spi_cs_deactive(struct bfin_sport_spi_slave_data *chip)
152 {
153 gpio_direction_output(chip->cs_gpio, 1);
154 /* Move delay here for consistency */
155 if (chip->cs_chg_udelay)
156 udelay(chip->cs_chg_udelay);
157 }
158
159 static void
bfin_sport_spi_stat_poll_complete(struct bfin_sport_spi_master_data * drv_data)160 bfin_sport_spi_stat_poll_complete(struct bfin_sport_spi_master_data *drv_data)
161 {
162 unsigned long timeout = jiffies + HZ;
163 while (!(bfin_read(&drv_data->regs->stat) & RXNE)) {
164 if (!time_before(jiffies, timeout))
165 break;
166 }
167 }
168
169 static void
bfin_sport_spi_u8_writer(struct bfin_sport_spi_master_data * drv_data)170 bfin_sport_spi_u8_writer(struct bfin_sport_spi_master_data *drv_data)
171 {
172 u16 dummy;
173
174 while (drv_data->tx < drv_data->tx_end) {
175 bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
176 bfin_sport_spi_stat_poll_complete(drv_data);
177 dummy = bfin_read(&drv_data->regs->rx16);
178 }
179 }
180
181 static void
bfin_sport_spi_u8_reader(struct bfin_sport_spi_master_data * drv_data)182 bfin_sport_spi_u8_reader(struct bfin_sport_spi_master_data *drv_data)
183 {
184 u16 tx_val = drv_data->cur_chip->idle_tx_val;
185
186 while (drv_data->rx < drv_data->rx_end) {
187 bfin_write(&drv_data->regs->tx16, tx_val);
188 bfin_sport_spi_stat_poll_complete(drv_data);
189 *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
190 }
191 }
192
193 static void
bfin_sport_spi_u8_duplex(struct bfin_sport_spi_master_data * drv_data)194 bfin_sport_spi_u8_duplex(struct bfin_sport_spi_master_data *drv_data)
195 {
196 while (drv_data->rx < drv_data->rx_end) {
197 bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
198 bfin_sport_spi_stat_poll_complete(drv_data);
199 *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
200 }
201 }
202
203 static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u8 = {
204 .write = bfin_sport_spi_u8_writer,
205 .read = bfin_sport_spi_u8_reader,
206 .duplex = bfin_sport_spi_u8_duplex,
207 };
208
209 static void
bfin_sport_spi_u16_writer(struct bfin_sport_spi_master_data * drv_data)210 bfin_sport_spi_u16_writer(struct bfin_sport_spi_master_data *drv_data)
211 {
212 u16 dummy;
213
214 while (drv_data->tx < drv_data->tx_end) {
215 bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
216 bfin_sport_spi_stat_poll_complete(drv_data);
217 dummy = bfin_read(&drv_data->regs->rx16);
218 }
219 }
220
221 static void
bfin_sport_spi_u16_reader(struct bfin_sport_spi_master_data * drv_data)222 bfin_sport_spi_u16_reader(struct bfin_sport_spi_master_data *drv_data)
223 {
224 u16 tx_val = drv_data->cur_chip->idle_tx_val;
225
226 while (drv_data->rx < drv_data->rx_end) {
227 bfin_write(&drv_data->regs->tx16, tx_val);
228 bfin_sport_spi_stat_poll_complete(drv_data);
229 *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
230 }
231 }
232
233 static void
bfin_sport_spi_u16_duplex(struct bfin_sport_spi_master_data * drv_data)234 bfin_sport_spi_u16_duplex(struct bfin_sport_spi_master_data *drv_data)
235 {
236 while (drv_data->rx < drv_data->rx_end) {
237 bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
238 bfin_sport_spi_stat_poll_complete(drv_data);
239 *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
240 }
241 }
242
243 static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u16 = {
244 .write = bfin_sport_spi_u16_writer,
245 .read = bfin_sport_spi_u16_reader,
246 .duplex = bfin_sport_spi_u16_duplex,
247 };
248
249 /* stop controller and re-config current chip */
250 static void
bfin_sport_spi_restore_state(struct bfin_sport_spi_master_data * drv_data)251 bfin_sport_spi_restore_state(struct bfin_sport_spi_master_data *drv_data)
252 {
253 struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
254
255 bfin_sport_spi_disable(drv_data);
256 dev_dbg(drv_data->dev, "restoring spi ctl state\n");
257
258 bfin_write(&drv_data->regs->tcr1, chip->ctl_reg);
259 bfin_write(&drv_data->regs->tclkdiv, chip->baud);
260 SSYNC();
261
262 bfin_write(&drv_data->regs->rcr1, chip->ctl_reg & ~(ITCLK | ITFS));
263 SSYNC();
264
265 bfin_sport_spi_cs_active(chip);
266 }
267
268 /* test if there is more transfer to be done */
269 static enum bfin_sport_spi_state
bfin_sport_spi_next_transfer(struct bfin_sport_spi_master_data * drv_data)270 bfin_sport_spi_next_transfer(struct bfin_sport_spi_master_data *drv_data)
271 {
272 struct spi_message *msg = drv_data->cur_msg;
273 struct spi_transfer *trans = drv_data->cur_transfer;
274
275 /* Move to next transfer */
276 if (trans->transfer_list.next != &msg->transfers) {
277 drv_data->cur_transfer =
278 list_entry(trans->transfer_list.next,
279 struct spi_transfer, transfer_list);
280 return RUNNING_STATE;
281 }
282
283 return DONE_STATE;
284 }
285
286 /*
287 * caller already set message->status;
288 * dma and pio irqs are blocked give finished message back
289 */
290 static void
bfin_sport_spi_giveback(struct bfin_sport_spi_master_data * drv_data)291 bfin_sport_spi_giveback(struct bfin_sport_spi_master_data *drv_data)
292 {
293 struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
294 unsigned long flags;
295 struct spi_message *msg;
296
297 spin_lock_irqsave(&drv_data->lock, flags);
298 msg = drv_data->cur_msg;
299 drv_data->state = START_STATE;
300 drv_data->cur_msg = NULL;
301 drv_data->cur_transfer = NULL;
302 drv_data->cur_chip = NULL;
303 queue_work(drv_data->workqueue, &drv_data->pump_messages);
304 spin_unlock_irqrestore(&drv_data->lock, flags);
305
306 if (!drv_data->cs_change)
307 bfin_sport_spi_cs_deactive(chip);
308
309 if (msg->complete)
310 msg->complete(msg->context);
311 }
312
313 static irqreturn_t
sport_err_handler(int irq,void * dev_id)314 sport_err_handler(int irq, void *dev_id)
315 {
316 struct bfin_sport_spi_master_data *drv_data = dev_id;
317 u16 status;
318
319 dev_dbg(drv_data->dev, "%s enter\n", __func__);
320 status = bfin_read(&drv_data->regs->stat) & (TOVF | TUVF | ROVF | RUVF);
321
322 if (status) {
323 bfin_write(&drv_data->regs->stat, status);
324 SSYNC();
325
326 bfin_sport_spi_disable(drv_data);
327 dev_err(drv_data->dev, "status error:%s%s%s%s\n",
328 status & TOVF ? " TOVF" : "",
329 status & TUVF ? " TUVF" : "",
330 status & ROVF ? " ROVF" : "",
331 status & RUVF ? " RUVF" : "");
332 }
333
334 return IRQ_HANDLED;
335 }
336
337 static void
bfin_sport_spi_pump_transfers(unsigned long data)338 bfin_sport_spi_pump_transfers(unsigned long data)
339 {
340 struct bfin_sport_spi_master_data *drv_data = (void *)data;
341 struct spi_message *message = NULL;
342 struct spi_transfer *transfer = NULL;
343 struct spi_transfer *previous = NULL;
344 struct bfin_sport_spi_slave_data *chip = NULL;
345 unsigned int bits_per_word;
346 u32 tranf_success = 1;
347 u32 transfer_speed;
348 u8 full_duplex = 0;
349
350 /* Get current state information */
351 message = drv_data->cur_msg;
352 transfer = drv_data->cur_transfer;
353 chip = drv_data->cur_chip;
354
355 if (transfer->speed_hz)
356 transfer_speed = bfin_sport_hz_to_spi_baud(transfer->speed_hz);
357 else
358 transfer_speed = chip->baud;
359 bfin_write(&drv_data->regs->tclkdiv, transfer_speed);
360 SSYNC();
361
362 /*
363 * if msg is error or done, report it back using complete() callback
364 */
365
366 /* Handle for abort */
367 if (drv_data->state == ERROR_STATE) {
368 dev_dbg(drv_data->dev, "transfer: we've hit an error\n");
369 message->status = -EIO;
370 bfin_sport_spi_giveback(drv_data);
371 return;
372 }
373
374 /* Handle end of message */
375 if (drv_data->state == DONE_STATE) {
376 dev_dbg(drv_data->dev, "transfer: all done!\n");
377 message->status = 0;
378 bfin_sport_spi_giveback(drv_data);
379 return;
380 }
381
382 /* Delay if requested at end of transfer */
383 if (drv_data->state == RUNNING_STATE) {
384 dev_dbg(drv_data->dev, "transfer: still running ...\n");
385 previous = list_entry(transfer->transfer_list.prev,
386 struct spi_transfer, transfer_list);
387 if (previous->delay_usecs)
388 udelay(previous->delay_usecs);
389 }
390
391 if (transfer->len == 0) {
392 /* Move to next transfer of this msg */
393 drv_data->state = bfin_sport_spi_next_transfer(drv_data);
394 /* Schedule next transfer tasklet */
395 tasklet_schedule(&drv_data->pump_transfers);
396 }
397
398 if (transfer->tx_buf != NULL) {
399 drv_data->tx = (void *)transfer->tx_buf;
400 drv_data->tx_end = drv_data->tx + transfer->len;
401 dev_dbg(drv_data->dev, "tx_buf is %p, tx_end is %p\n",
402 transfer->tx_buf, drv_data->tx_end);
403 } else
404 drv_data->tx = NULL;
405
406 if (transfer->rx_buf != NULL) {
407 full_duplex = transfer->tx_buf != NULL;
408 drv_data->rx = transfer->rx_buf;
409 drv_data->rx_end = drv_data->rx + transfer->len;
410 dev_dbg(drv_data->dev, "rx_buf is %p, rx_end is %p\n",
411 transfer->rx_buf, drv_data->rx_end);
412 } else
413 drv_data->rx = NULL;
414
415 drv_data->cs_change = transfer->cs_change;
416
417 /* Bits per word setup */
418 bits_per_word = transfer->bits_per_word;
419 if (bits_per_word == 16)
420 drv_data->ops = &bfin_sport_transfer_ops_u16;
421 else
422 drv_data->ops = &bfin_sport_transfer_ops_u8;
423 bfin_write(&drv_data->regs->tcr2, bits_per_word - 1);
424 bfin_write(&drv_data->regs->tfsdiv, bits_per_word - 1);
425 bfin_write(&drv_data->regs->rcr2, bits_per_word - 1);
426
427 drv_data->state = RUNNING_STATE;
428
429 if (drv_data->cs_change)
430 bfin_sport_spi_cs_active(chip);
431
432 dev_dbg(drv_data->dev,
433 "now pumping a transfer: width is %d, len is %d\n",
434 bits_per_word, transfer->len);
435
436 /* PIO mode write then read */
437 dev_dbg(drv_data->dev, "doing IO transfer\n");
438
439 bfin_sport_spi_enable(drv_data);
440 if (full_duplex) {
441 /* full duplex mode */
442 BUG_ON((drv_data->tx_end - drv_data->tx) !=
443 (drv_data->rx_end - drv_data->rx));
444 drv_data->ops->duplex(drv_data);
445
446 if (drv_data->tx != drv_data->tx_end)
447 tranf_success = 0;
448 } else if (drv_data->tx != NULL) {
449 /* write only half duplex */
450
451 drv_data->ops->write(drv_data);
452
453 if (drv_data->tx != drv_data->tx_end)
454 tranf_success = 0;
455 } else if (drv_data->rx != NULL) {
456 /* read only half duplex */
457
458 drv_data->ops->read(drv_data);
459 if (drv_data->rx != drv_data->rx_end)
460 tranf_success = 0;
461 }
462 bfin_sport_spi_disable(drv_data);
463
464 if (!tranf_success) {
465 dev_dbg(drv_data->dev, "IO write error!\n");
466 drv_data->state = ERROR_STATE;
467 } else {
468 /* Update total byte transferred */
469 message->actual_length += transfer->len;
470 /* Move to next transfer of this msg */
471 drv_data->state = bfin_sport_spi_next_transfer(drv_data);
472 if (drv_data->cs_change)
473 bfin_sport_spi_cs_deactive(chip);
474 }
475
476 /* Schedule next transfer tasklet */
477 tasklet_schedule(&drv_data->pump_transfers);
478 }
479
480 /* pop a msg from queue and kick off real transfer */
481 static void
bfin_sport_spi_pump_messages(struct work_struct * work)482 bfin_sport_spi_pump_messages(struct work_struct *work)
483 {
484 struct bfin_sport_spi_master_data *drv_data;
485 unsigned long flags;
486 struct spi_message *next_msg;
487
488 drv_data = container_of(work, struct bfin_sport_spi_master_data, pump_messages);
489
490 /* Lock queue and check for queue work */
491 spin_lock_irqsave(&drv_data->lock, flags);
492 if (list_empty(&drv_data->queue) || !drv_data->run) {
493 /* pumper kicked off but no work to do */
494 drv_data->busy = 0;
495 spin_unlock_irqrestore(&drv_data->lock, flags);
496 return;
497 }
498
499 /* Make sure we are not already running a message */
500 if (drv_data->cur_msg) {
501 spin_unlock_irqrestore(&drv_data->lock, flags);
502 return;
503 }
504
505 /* Extract head of queue */
506 next_msg = list_entry(drv_data->queue.next,
507 struct spi_message, queue);
508
509 drv_data->cur_msg = next_msg;
510
511 /* Setup the SSP using the per chip configuration */
512 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
513
514 list_del_init(&drv_data->cur_msg->queue);
515
516 /* Initialize message state */
517 drv_data->cur_msg->state = START_STATE;
518 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
519 struct spi_transfer, transfer_list);
520 bfin_sport_spi_restore_state(drv_data);
521 dev_dbg(drv_data->dev, "got a message to pump, "
522 "state is set to: baud %d, cs_gpio %i, ctl 0x%x\n",
523 drv_data->cur_chip->baud, drv_data->cur_chip->cs_gpio,
524 drv_data->cur_chip->ctl_reg);
525
526 dev_dbg(drv_data->dev,
527 "the first transfer len is %d\n",
528 drv_data->cur_transfer->len);
529
530 /* Mark as busy and launch transfers */
531 tasklet_schedule(&drv_data->pump_transfers);
532
533 drv_data->busy = 1;
534 spin_unlock_irqrestore(&drv_data->lock, flags);
535 }
536
537 /*
538 * got a msg to transfer, queue it in drv_data->queue.
539 * And kick off message pumper
540 */
541 static int
bfin_sport_spi_transfer(struct spi_device * spi,struct spi_message * msg)542 bfin_sport_spi_transfer(struct spi_device *spi, struct spi_message *msg)
543 {
544 struct bfin_sport_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
545 unsigned long flags;
546
547 spin_lock_irqsave(&drv_data->lock, flags);
548
549 if (!drv_data->run) {
550 spin_unlock_irqrestore(&drv_data->lock, flags);
551 return -ESHUTDOWN;
552 }
553
554 msg->actual_length = 0;
555 msg->status = -EINPROGRESS;
556 msg->state = START_STATE;
557
558 dev_dbg(&spi->dev, "adding an msg in transfer()\n");
559 list_add_tail(&msg->queue, &drv_data->queue);
560
561 if (drv_data->run && !drv_data->busy)
562 queue_work(drv_data->workqueue, &drv_data->pump_messages);
563
564 spin_unlock_irqrestore(&drv_data->lock, flags);
565
566 return 0;
567 }
568
569 /* Called every time common spi devices change state */
570 static int
bfin_sport_spi_setup(struct spi_device * spi)571 bfin_sport_spi_setup(struct spi_device *spi)
572 {
573 struct bfin_sport_spi_slave_data *chip, *first = NULL;
574 int ret;
575
576 /* Only alloc (or use chip_info) on first setup */
577 chip = spi_get_ctldata(spi);
578 if (chip == NULL) {
579 struct bfin5xx_spi_chip *chip_info;
580
581 chip = first = kzalloc(sizeof(*chip), GFP_KERNEL);
582 if (!chip)
583 return -ENOMEM;
584
585 /* platform chip_info isn't required */
586 chip_info = spi->controller_data;
587 if (chip_info) {
588 /*
589 * DITFS and TDTYPE are only thing we don't set, but
590 * they probably shouldn't be changed by people.
591 */
592 if (chip_info->ctl_reg || chip_info->enable_dma) {
593 ret = -EINVAL;
594 dev_err(&spi->dev, "don't set ctl_reg/enable_dma fields\n");
595 goto error;
596 }
597 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
598 chip->idle_tx_val = chip_info->idle_tx_val;
599 }
600 }
601
602 /* translate common spi framework into our register
603 * following configure contents are same for tx and rx.
604 */
605
606 if (spi->mode & SPI_CPHA)
607 chip->ctl_reg &= ~TCKFE;
608 else
609 chip->ctl_reg |= TCKFE;
610
611 if (spi->mode & SPI_LSB_FIRST)
612 chip->ctl_reg |= TLSBIT;
613 else
614 chip->ctl_reg &= ~TLSBIT;
615
616 /* Sport in master mode */
617 chip->ctl_reg |= ITCLK | ITFS | TFSR | LATFS | LTFS;
618
619 chip->baud = bfin_sport_hz_to_spi_baud(spi->max_speed_hz);
620
621 chip->cs_gpio = spi->chip_select;
622 ret = gpio_request(chip->cs_gpio, spi->modalias);
623 if (ret)
624 goto error;
625
626 dev_dbg(&spi->dev, "setup spi chip %s, width is %d\n",
627 spi->modalias, spi->bits_per_word);
628 dev_dbg(&spi->dev, "ctl_reg is 0x%x, GPIO is %i\n",
629 chip->ctl_reg, spi->chip_select);
630
631 spi_set_ctldata(spi, chip);
632
633 bfin_sport_spi_cs_deactive(chip);
634
635 return ret;
636
637 error:
638 kfree(first);
639 return ret;
640 }
641
642 /*
643 * callback for spi framework.
644 * clean driver specific data
645 */
646 static void
bfin_sport_spi_cleanup(struct spi_device * spi)647 bfin_sport_spi_cleanup(struct spi_device *spi)
648 {
649 struct bfin_sport_spi_slave_data *chip = spi_get_ctldata(spi);
650
651 if (!chip)
652 return;
653
654 gpio_free(chip->cs_gpio);
655
656 kfree(chip);
657 }
658
659 static int
bfin_sport_spi_init_queue(struct bfin_sport_spi_master_data * drv_data)660 bfin_sport_spi_init_queue(struct bfin_sport_spi_master_data *drv_data)
661 {
662 INIT_LIST_HEAD(&drv_data->queue);
663 spin_lock_init(&drv_data->lock);
664
665 drv_data->run = false;
666 drv_data->busy = 0;
667
668 /* init transfer tasklet */
669 tasklet_init(&drv_data->pump_transfers,
670 bfin_sport_spi_pump_transfers, (unsigned long)drv_data);
671
672 /* init messages workqueue */
673 INIT_WORK(&drv_data->pump_messages, bfin_sport_spi_pump_messages);
674 drv_data->workqueue =
675 create_singlethread_workqueue(dev_name(drv_data->master->dev.parent));
676 if (drv_data->workqueue == NULL)
677 return -EBUSY;
678
679 return 0;
680 }
681
682 static int
bfin_sport_spi_start_queue(struct bfin_sport_spi_master_data * drv_data)683 bfin_sport_spi_start_queue(struct bfin_sport_spi_master_data *drv_data)
684 {
685 unsigned long flags;
686
687 spin_lock_irqsave(&drv_data->lock, flags);
688
689 if (drv_data->run || drv_data->busy) {
690 spin_unlock_irqrestore(&drv_data->lock, flags);
691 return -EBUSY;
692 }
693
694 drv_data->run = true;
695 drv_data->cur_msg = NULL;
696 drv_data->cur_transfer = NULL;
697 drv_data->cur_chip = NULL;
698 spin_unlock_irqrestore(&drv_data->lock, flags);
699
700 queue_work(drv_data->workqueue, &drv_data->pump_messages);
701
702 return 0;
703 }
704
705 static inline int
bfin_sport_spi_stop_queue(struct bfin_sport_spi_master_data * drv_data)706 bfin_sport_spi_stop_queue(struct bfin_sport_spi_master_data *drv_data)
707 {
708 unsigned long flags;
709 unsigned limit = 500;
710 int status = 0;
711
712 spin_lock_irqsave(&drv_data->lock, flags);
713
714 /*
715 * This is a bit lame, but is optimized for the common execution path.
716 * A wait_queue on the drv_data->busy could be used, but then the common
717 * execution path (pump_messages) would be required to call wake_up or
718 * friends on every SPI message. Do this instead
719 */
720 drv_data->run = false;
721 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
722 spin_unlock_irqrestore(&drv_data->lock, flags);
723 msleep(10);
724 spin_lock_irqsave(&drv_data->lock, flags);
725 }
726
727 if (!list_empty(&drv_data->queue) || drv_data->busy)
728 status = -EBUSY;
729
730 spin_unlock_irqrestore(&drv_data->lock, flags);
731
732 return status;
733 }
734
735 static inline int
bfin_sport_spi_destroy_queue(struct bfin_sport_spi_master_data * drv_data)736 bfin_sport_spi_destroy_queue(struct bfin_sport_spi_master_data *drv_data)
737 {
738 int status;
739
740 status = bfin_sport_spi_stop_queue(drv_data);
741 if (status)
742 return status;
743
744 destroy_workqueue(drv_data->workqueue);
745
746 return 0;
747 }
748
bfin_sport_spi_probe(struct platform_device * pdev)749 static int bfin_sport_spi_probe(struct platform_device *pdev)
750 {
751 struct device *dev = &pdev->dev;
752 struct bfin5xx_spi_master *platform_info;
753 struct spi_master *master;
754 struct resource *res, *ires;
755 struct bfin_sport_spi_master_data *drv_data;
756 int status;
757
758 platform_info = dev_get_platdata(dev);
759
760 /* Allocate master with space for drv_data */
761 master = spi_alloc_master(dev, sizeof(*master) + 16);
762 if (!master) {
763 dev_err(dev, "cannot alloc spi_master\n");
764 return -ENOMEM;
765 }
766
767 drv_data = spi_master_get_devdata(master);
768 drv_data->master = master;
769 drv_data->dev = dev;
770 drv_data->pin_req = platform_info->pin_req;
771
772 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
773 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
774 master->bus_num = pdev->id;
775 master->num_chipselect = platform_info->num_chipselect;
776 master->cleanup = bfin_sport_spi_cleanup;
777 master->setup = bfin_sport_spi_setup;
778 master->transfer = bfin_sport_spi_transfer;
779
780 /* Find and map our resources */
781 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
782 if (res == NULL) {
783 dev_err(dev, "cannot get IORESOURCE_MEM\n");
784 status = -ENOENT;
785 goto out_error_get_res;
786 }
787
788 drv_data->regs = ioremap(res->start, resource_size(res));
789 if (drv_data->regs == NULL) {
790 dev_err(dev, "cannot map registers\n");
791 status = -ENXIO;
792 goto out_error_ioremap;
793 }
794
795 ires = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
796 if (!ires) {
797 dev_err(dev, "cannot get IORESOURCE_IRQ\n");
798 status = -ENODEV;
799 goto out_error_get_ires;
800 }
801 drv_data->err_irq = ires->start;
802
803 /* Initial and start queue */
804 status = bfin_sport_spi_init_queue(drv_data);
805 if (status) {
806 dev_err(dev, "problem initializing queue\n");
807 goto out_error_queue_alloc;
808 }
809
810 status = bfin_sport_spi_start_queue(drv_data);
811 if (status) {
812 dev_err(dev, "problem starting queue\n");
813 goto out_error_queue_alloc;
814 }
815
816 status = request_irq(drv_data->err_irq, sport_err_handler,
817 0, "sport_spi_err", drv_data);
818 if (status) {
819 dev_err(dev, "unable to request sport err irq\n");
820 goto out_error_irq;
821 }
822
823 status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
824 if (status) {
825 dev_err(dev, "requesting peripherals failed\n");
826 goto out_error_peripheral;
827 }
828
829 /* Register with the SPI framework */
830 platform_set_drvdata(pdev, drv_data);
831 status = spi_register_master(master);
832 if (status) {
833 dev_err(dev, "problem registering spi master\n");
834 goto out_error_master;
835 }
836
837 dev_info(dev, "%s, regs_base@%p\n", DRV_DESC, drv_data->regs);
838 return 0;
839
840 out_error_master:
841 peripheral_free_list(drv_data->pin_req);
842 out_error_peripheral:
843 free_irq(drv_data->err_irq, drv_data);
844 out_error_irq:
845 out_error_queue_alloc:
846 bfin_sport_spi_destroy_queue(drv_data);
847 out_error_get_ires:
848 iounmap(drv_data->regs);
849 out_error_ioremap:
850 out_error_get_res:
851 spi_master_put(master);
852
853 return status;
854 }
855
856 /* stop hardware and remove the driver */
bfin_sport_spi_remove(struct platform_device * pdev)857 static int bfin_sport_spi_remove(struct platform_device *pdev)
858 {
859 struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
860 int status = 0;
861
862 if (!drv_data)
863 return 0;
864
865 /* Remove the queue */
866 status = bfin_sport_spi_destroy_queue(drv_data);
867 if (status)
868 return status;
869
870 /* Disable the SSP at the peripheral and SOC level */
871 bfin_sport_spi_disable(drv_data);
872
873 /* Disconnect from the SPI framework */
874 spi_unregister_master(drv_data->master);
875
876 peripheral_free_list(drv_data->pin_req);
877
878 return 0;
879 }
880
881 #ifdef CONFIG_PM_SLEEP
bfin_sport_spi_suspend(struct device * dev)882 static int bfin_sport_spi_suspend(struct device *dev)
883 {
884 struct bfin_sport_spi_master_data *drv_data = dev_get_drvdata(dev);
885 int status;
886
887 status = bfin_sport_spi_stop_queue(drv_data);
888 if (status)
889 return status;
890
891 /* stop hardware */
892 bfin_sport_spi_disable(drv_data);
893
894 return status;
895 }
896
bfin_sport_spi_resume(struct device * dev)897 static int bfin_sport_spi_resume(struct device *dev)
898 {
899 struct bfin_sport_spi_master_data *drv_data = dev_get_drvdata(dev);
900 int status;
901
902 /* Enable the SPI interface */
903 bfin_sport_spi_enable(drv_data);
904
905 /* Start the queue running */
906 status = bfin_sport_spi_start_queue(drv_data);
907 if (status)
908 dev_err(drv_data->dev, "problem resuming queue\n");
909
910 return status;
911 }
912
913 static SIMPLE_DEV_PM_OPS(bfin_sport_spi_pm_ops, bfin_sport_spi_suspend,
914 bfin_sport_spi_resume);
915
916 #define BFIN_SPORT_SPI_PM_OPS (&bfin_sport_spi_pm_ops)
917 #else
918 #define BFIN_SPORT_SPI_PM_OPS NULL
919 #endif
920
921 static struct platform_driver bfin_sport_spi_driver = {
922 .driver = {
923 .name = DRV_NAME,
924 .owner = THIS_MODULE,
925 .pm = BFIN_SPORT_SPI_PM_OPS,
926 },
927 .probe = bfin_sport_spi_probe,
928 .remove = bfin_sport_spi_remove,
929 };
930 module_platform_driver(bfin_sport_spi_driver);
931