projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[deliverable/linux.git] / drivers / spi / spi-dw.c
1 /*
2 * Designware SPI core controller driver (refer pxa2xx_spi.c)
3 *
4 * Copyright (c) 2009, 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 #include <linux/dma-mapping.h>
21 #include <linux/interrupt.h>
22 #include <linux/module.h>
23 #include <linux/highmem.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/spi/spi.h>
27
28 #include "spi-dw.h"
29
30 #ifdef CONFIG_DEBUG_FS
31 #include <linux/debugfs.h>
32 #endif
33
34 #define START_STATE ((void *)0)
35 #define RUNNING_STATE ((void *)1)
36 #define DONE_STATE ((void *)2)
37 #define ERROR_STATE ((void *)-1)
38
39 #define QUEUE_RUNNING 0
40 #define QUEUE_STOPPED 1
41
42 #define MRST_SPI_DEASSERT 0
43 #define MRST_SPI_ASSERT 1
44
45 /* Slave spi_dev related */
46 struct chip_data {
47 u16 cr0;
48 u8 cs; /* chip select pin */
49 u8 n_bytes; /* current is a 1/2/4 byte op */
50 u8 tmode; /* TR/TO/RO/EEPROM */
51 u8 type; /* SPI/SSP/MicroWire */
52
53 u8 poll_mode; /* 1 means use poll mode */
54
55 u32 dma_width;
56 u32 rx_threshold;
57 u32 tx_threshold;
58 u8 enable_dma;
59 u8 bits_per_word;
60 u16 clk_div; /* baud rate divider */
61 u32 speed_hz; /* baud rate */
62 void (*cs_control)(u32 command);
63 };
64
65 #ifdef CONFIG_DEBUG_FS
66 #define SPI_REGS_BUFSIZE 1024
67 static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
68 size_t count, loff_t *ppos)
69 {
70 struct dw_spi *dws;
71 char *buf;
72 u32 len = 0;
73 ssize_t ret;
74
75 dws = file->private_data;
76
77 buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
78 if (!buf)
79 return 0;
80
81 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
82 "MRST SPI0 registers:\n");
83 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
84 "=================================\n");
85 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
86 "CTRL0: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL0));
87 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
88 "CTRL1: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL1));
89 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
90 "SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR));
91 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
92 "SER: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SER));
93 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
94 "BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR));
95 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
96 "TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFLTR));
97 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
98 "RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFLTR));
99 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
100 "TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR));
101 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
102 "RXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_RXFLR));
103 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
104 "SR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SR));
105 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
106 "IMR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_IMR));
107 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
108 "ISR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_ISR));
109 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
110 "DMACR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_DMACR));
111 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
112 "DMATDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMATDLR));
113 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
114 "DMARDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMARDLR));
115 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
116 "=================================\n");
117
118 ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
119 kfree(buf);
120 return ret;
121 }
122
123 static const struct file_operations mrst_spi_regs_ops = {
124 .owner = THIS_MODULE,
125 .open = simple_open,
126 .read = spi_show_regs,
127 .llseek = default_llseek,
128 };
129
130 static int mrst_spi_debugfs_init(struct dw_spi *dws)
131 {
132 dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
133 if (!dws->debugfs)
134 return -ENOMEM;
135
136 debugfs_create_file("registers", S_IFREG | S_IRUGO,
137 dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
138 return 0;
139 }
140
141 static void mrst_spi_debugfs_remove(struct dw_spi *dws)
142 {
143 if (dws->debugfs)
144 debugfs_remove_recursive(dws->debugfs);
145 }
146
147 #else
148 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
149 {
150 return 0;
151 }
152
153 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
154 {
155 }
156 #endif /* CONFIG_DEBUG_FS */
157
158 /* Return the max entries we can fill into tx fifo */
159 static inline u32 tx_max(struct dw_spi *dws)
160 {
161 u32 tx_left, tx_room, rxtx_gap;
162
163 tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
164 tx_room = dws->fifo_len - dw_readw(dws, DW_SPI_TXFLR);
165
166 /*
167 * Another concern is about the tx/rx mismatch, we
168 * though to use (dws->fifo_len - rxflr - txflr) as
169 * one maximum value for tx, but it doesn't cover the
170 * data which is out of tx/rx fifo and inside the
171 * shift registers. So a control from sw point of
172 * view is taken.
173 */
174 rxtx_gap = ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
175 / dws->n_bytes;
176
177 return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
178 }
179
180 /* Return the max entries we should read out of rx fifo */
181 static inline u32 rx_max(struct dw_spi *dws)
182 {
183 u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
184
185 return min(rx_left, (u32)dw_readw(dws, DW_SPI_RXFLR));
186 }
187
188 static void dw_writer(struct dw_spi *dws)
189 {
190 u32 max = tx_max(dws);
191 u16 txw = 0;
192
193 while (max--) {
194 /* Set the tx word if the transfer's original "tx" is not null */
195 if (dws->tx_end - dws->len) {
196 if (dws->n_bytes == 1)
197 txw = *(u8 *)(dws->tx);
198 else
199 txw = *(u16 *)(dws->tx);
200 }
201 dw_writew(dws, DW_SPI_DR, txw);
202 dws->tx += dws->n_bytes;
203 }
204 }
205
206 static void dw_reader(struct dw_spi *dws)
207 {
208 u32 max = rx_max(dws);
209 u16 rxw;
210
211 while (max--) {
212 rxw = dw_readw(dws, DW_SPI_DR);
213 /* Care rx only if the transfer's original "rx" is not null */
214 if (dws->rx_end - dws->len) {
215 if (dws->n_bytes == 1)
216 *(u8 *)(dws->rx) = rxw;
217 else
218 *(u16 *)(dws->rx) = rxw;
219 }
220 dws->rx += dws->n_bytes;
221 }
222 }
223
224 static void *next_transfer(struct dw_spi *dws)
225 {
226 struct spi_message *msg = dws->cur_msg;
227 struct spi_transfer *trans = dws->cur_transfer;
228
229 /* Move to next transfer */
230 if (trans->transfer_list.next != &msg->transfers) {
231 dws->cur_transfer =
232 list_entry(trans->transfer_list.next,
233 struct spi_transfer,
234 transfer_list);
235 return RUNNING_STATE;
236 } else
237 return DONE_STATE;
238 }
239
240 /*
241 * Note: first step is the protocol driver prepares
242 * a dma-capable memory, and this func just need translate
243 * the virt addr to physical
244 */
245 static int map_dma_buffers(struct dw_spi *dws)
246 {
247 if (!dws->cur_msg->is_dma_mapped
248 || !dws->dma_inited
249 || !dws->cur_chip->enable_dma
250 || !dws->dma_ops)
251 return 0;
252
253 if (dws->cur_transfer->tx_dma)
254 dws->tx_dma = dws->cur_transfer->tx_dma;
255
256 if (dws->cur_transfer->rx_dma)
257 dws->rx_dma = dws->cur_transfer->rx_dma;
258
259 return 1;
260 }
261
262 /* Caller already set message->status; dma and pio irqs are blocked */
263 static void giveback(struct dw_spi *dws)
264 {
265 struct spi_transfer *last_transfer;
266 unsigned long flags;
267 struct spi_message *msg;
268
269 spin_lock_irqsave(&dws->lock, flags);
270 msg = dws->cur_msg;
271 dws->cur_msg = NULL;
272 dws->cur_transfer = NULL;
273 dws->prev_chip = dws->cur_chip;
274 dws->cur_chip = NULL;
275 dws->dma_mapped = 0;
276 queue_work(dws->workqueue, &dws->pump_messages);
277 spin_unlock_irqrestore(&dws->lock, flags);
278
279 last_transfer = list_entry(msg->transfers.prev,
280 struct spi_transfer,
281 transfer_list);
282
283 if (!last_transfer->cs_change && dws->cs_control)
284 dws->cs_control(MRST_SPI_DEASSERT);
285
286 msg->state = NULL;
287 if (msg->complete)
288 msg->complete(msg->context);
289 }
290
291 static void int_error_stop(struct dw_spi *dws, const char *msg)
292 {
293 /* Stop the hw */
294 spi_enable_chip(dws, 0);
295
296 dev_err(&dws->master->dev, "%s\n", msg);
297 dws->cur_msg->state = ERROR_STATE;
298 tasklet_schedule(&dws->pump_transfers);
299 }
300
301 void dw_spi_xfer_done(struct dw_spi *dws)
302 {
303 /* Update total byte transferred return count actual bytes read */
304 dws->cur_msg->actual_length += dws->len;
305
306 /* Move to next transfer */
307 dws->cur_msg->state = next_transfer(dws);
308
309 /* Handle end of message */
310 if (dws->cur_msg->state == DONE_STATE) {
311 dws->cur_msg->status = 0;
312 giveback(dws);
313 } else
314 tasklet_schedule(&dws->pump_transfers);
315 }
316 EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
317
318 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
319 {
320 u16 irq_status = dw_readw(dws, DW_SPI_ISR);
321
322 /* Error handling */
323 if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
324 dw_readw(dws, DW_SPI_TXOICR);
325 dw_readw(dws, DW_SPI_RXOICR);
326 dw_readw(dws, DW_SPI_RXUICR);
327 int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
328 return IRQ_HANDLED;
329 }
330
331 dw_reader(dws);
332 if (dws->rx_end == dws->rx) {
333 spi_mask_intr(dws, SPI_INT_TXEI);
334 dw_spi_xfer_done(dws);
335 return IRQ_HANDLED;
336 }
337 if (irq_status & SPI_INT_TXEI) {
338 spi_mask_intr(dws, SPI_INT_TXEI);
339 dw_writer(dws);
340 /* Enable TX irq always, it will be disabled when RX finished */
341 spi_umask_intr(dws, SPI_INT_TXEI);
342 }
343
344 return IRQ_HANDLED;
345 }
346
347 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
348 {
349 struct dw_spi *dws = dev_id;
350 u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f;
351
352 if (!irq_status)
353 return IRQ_NONE;
354
355 if (!dws->cur_msg) {
356 spi_mask_intr(dws, SPI_INT_TXEI);
357 return IRQ_HANDLED;
358 }
359
360 return dws->transfer_handler(dws);
361 }
362
363 /* Must be called inside pump_transfers() */
364 static void poll_transfer(struct dw_spi *dws)
365 {
366 do {
367 dw_writer(dws);
368 dw_reader(dws);
369 cpu_relax();
370 } while (dws->rx_end > dws->rx);
371
372 dw_spi_xfer_done(dws);
373 }
374
375 static void pump_transfers(unsigned long data)
376 {
377 struct dw_spi *dws = (struct dw_spi *)data;
378 struct spi_message *message = NULL;
379 struct spi_transfer *transfer = NULL;
380 struct spi_transfer *previous = NULL;
381 struct spi_device *spi = NULL;
382 struct chip_data *chip = NULL;
383 u8 bits = 0;
384 u8 imask = 0;
385 u8 cs_change = 0;
386 u16 txint_level = 0;
387 u16 clk_div = 0;
388 u32 speed = 0;
389 u32 cr0 = 0;
390
391 /* Get current state information */
392 message = dws->cur_msg;
393 transfer = dws->cur_transfer;
394 chip = dws->cur_chip;
395 spi = message->spi;
396
397 if (unlikely(!chip->clk_div))
398 chip->clk_div = dws->max_freq / chip->speed_hz;
399
400 if (message->state == ERROR_STATE) {
401 message->status = -EIO;
402 goto early_exit;
403 }
404
405 /* Handle end of message */
406 if (message->state == DONE_STATE) {
407 message->status = 0;
408 goto early_exit;
409 }
410
411 /* Delay if requested at end of transfer*/
412 if (message->state == RUNNING_STATE) {
413 previous = list_entry(transfer->transfer_list.prev,
414 struct spi_transfer,
415 transfer_list);
416 if (previous->delay_usecs)
417 udelay(previous->delay_usecs);
418 }
419
420 dws->n_bytes = chip->n_bytes;
421 dws->dma_width = chip->dma_width;
422 dws->cs_control = chip->cs_control;
423
424 dws->rx_dma = transfer->rx_dma;
425 dws->tx_dma = transfer->tx_dma;
426 dws->tx = (void *)transfer->tx_buf;
427 dws->tx_end = dws->tx + transfer->len;
428 dws->rx = transfer->rx_buf;
429 dws->rx_end = dws->rx + transfer->len;
430 dws->cs_change = transfer->cs_change;
431 dws->len = dws->cur_transfer->len;
432 if (chip != dws->prev_chip)
433 cs_change = 1;
434
435 cr0 = chip->cr0;
436
437 /* Handle per transfer options for bpw and speed */
438 if (transfer->speed_hz) {
439 speed = chip->speed_hz;
440
441 if (transfer->speed_hz != speed) {
442 speed = transfer->speed_hz;
443 if (speed > dws->max_freq) {
444 printk(KERN_ERR "MRST SPI0: unsupported"
445 "freq: %dHz\n", speed);
446 message->status = -EIO;
447 goto early_exit;
448 }
449
450 /* clk_div doesn't support odd number */
451 clk_div = dws->max_freq / speed;
452 clk_div = (clk_div + 1) & 0xfffe;
453
454 chip->speed_hz = speed;
455 chip->clk_div = clk_div;
456 }
457 }
458 if (transfer->bits_per_word) {
459 bits = transfer->bits_per_word;
460
461 switch (bits) {
462 case 8:
463 case 16:
464 dws->n_bytes = dws->dma_width = bits >> 3;
465 break;
466 default:
467 printk(KERN_ERR "MRST SPI0: unsupported bits:"
468 "%db\n", bits);
469 message->status = -EIO;
470 goto early_exit;
471 }
472
473 cr0 = (bits - 1)
474 | (chip->type << SPI_FRF_OFFSET)
475 | (spi->mode << SPI_MODE_OFFSET)
476 | (chip->tmode << SPI_TMOD_OFFSET);
477 }
478 message->state = RUNNING_STATE;
479
480 /*
481 * Adjust transfer mode if necessary. Requires platform dependent
482 * chipselect mechanism.
483 */
484 if (dws->cs_control) {
485 if (dws->rx && dws->tx)
486 chip->tmode = SPI_TMOD_TR;
487 else if (dws->rx)
488 chip->tmode = SPI_TMOD_RO;
489 else
490 chip->tmode = SPI_TMOD_TO;
491
492 cr0 &= ~SPI_TMOD_MASK;
493 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
494 }
495
496 /* Check if current transfer is a DMA transaction */
497 dws->dma_mapped = map_dma_buffers(dws);
498
499 /*
500 * Interrupt mode
501 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
502 */
503 if (!dws->dma_mapped && !chip->poll_mode) {
504 int templen = dws->len / dws->n_bytes;
505 txint_level = dws->fifo_len / 2;
506 txint_level = (templen > txint_level) ? txint_level : templen;
507
508 imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI;
509 dws->transfer_handler = interrupt_transfer;
510 }
511
512 /*
513 * Reprogram registers only if
514 * 1. chip select changes
515 * 2. clk_div is changed
516 * 3. control value changes
517 */
518 if (dw_readw(dws, DW_SPI_CTRL0) != cr0 || cs_change || clk_div || imask) {
519 spi_enable_chip(dws, 0);
520
521 if (dw_readw(dws, DW_SPI_CTRL0) != cr0)
522 dw_writew(dws, DW_SPI_CTRL0, cr0);
523
524 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
525 spi_chip_sel(dws, spi->chip_select);
526
527 /* Set the interrupt mask, for poll mode just disable all int */
528 spi_mask_intr(dws, 0xff);
529 if (imask)
530 spi_umask_intr(dws, imask);
531 if (txint_level)
532 dw_writew(dws, DW_SPI_TXFLTR, txint_level);
533
534 spi_enable_chip(dws, 1);
535 if (cs_change)
536 dws->prev_chip = chip;
537 }
538
539 if (dws->dma_mapped)
540 dws->dma_ops->dma_transfer(dws, cs_change);
541
542 if (chip->poll_mode)
543 poll_transfer(dws);
544
545 return;
546
547 early_exit:
548 giveback(dws);
549 return;
550 }
551
552 static void pump_messages(struct work_struct *work)
553 {
554 struct dw_spi *dws =
555 container_of(work, struct dw_spi, pump_messages);
556 unsigned long flags;
557
558 /* Lock queue and check for queue work */
559 spin_lock_irqsave(&dws->lock, flags);
560 if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
561 dws->busy = 0;
562 spin_unlock_irqrestore(&dws->lock, flags);
563 return;
564 }
565
566 /* Make sure we are not already running a message */
567 if (dws->cur_msg) {
568 spin_unlock_irqrestore(&dws->lock, flags);
569 return;
570 }
571
572 /* Extract head of queue */
573 dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
574 list_del_init(&dws->cur_msg->queue);
575
576 /* Initial message state*/
577 dws->cur_msg->state = START_STATE;
578 dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
579 struct spi_transfer,
580 transfer_list);
581 dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
582
583 /* Mark as busy and launch transfers */
584 tasklet_schedule(&dws->pump_transfers);
585
586 dws->busy = 1;
587 spin_unlock_irqrestore(&dws->lock, flags);
588 }
589
590 /* spi_device use this to queue in their spi_msg */
591 static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
592 {
593 struct dw_spi *dws = spi_master_get_devdata(spi->master);
594 unsigned long flags;
595
596 spin_lock_irqsave(&dws->lock, flags);
597
598 if (dws->run == QUEUE_STOPPED) {
599 spin_unlock_irqrestore(&dws->lock, flags);
600 return -ESHUTDOWN;
601 }
602
603 msg->actual_length = 0;
604 msg->status = -EINPROGRESS;
605 msg->state = START_STATE;
606
607 list_add_tail(&msg->queue, &dws->queue);
608
609 if (dws->run == QUEUE_RUNNING && !dws->busy) {
610
611 if (dws->cur_transfer || dws->cur_msg)
612 queue_work(dws->workqueue,
613 &dws->pump_messages);
614 else {
615 /* If no other data transaction in air, just go */
616 spin_unlock_irqrestore(&dws->lock, flags);
617 pump_messages(&dws->pump_messages);
618 return 0;
619 }
620 }
621
622 spin_unlock_irqrestore(&dws->lock, flags);
623 return 0;
624 }
625
626 /* This may be called twice for each spi dev */
627 static int dw_spi_setup(struct spi_device *spi)
628 {
629 struct dw_spi_chip *chip_info = NULL;
630 struct chip_data *chip;
631
632 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
633 return -EINVAL;
634
635 /* Only alloc on first setup */
636 chip = spi_get_ctldata(spi);
637 if (!chip) {
638 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
639 if (!chip)
640 return -ENOMEM;
641 }
642
643 /*
644 * Protocol drivers may change the chip settings, so...
645 * if chip_info exists, use it
646 */
647 chip_info = spi->controller_data;
648
649 /* chip_info doesn't always exist */
650 if (chip_info) {
651 if (chip_info->cs_control)
652 chip->cs_control = chip_info->cs_control;
653
654 chip->poll_mode = chip_info->poll_mode;
655 chip->type = chip_info->type;
656
657 chip->rx_threshold = 0;
658 chip->tx_threshold = 0;
659
660 chip->enable_dma = chip_info->enable_dma;
661 }
662
663 if (spi->bits_per_word <= 8) {
664 chip->n_bytes = 1;
665 chip->dma_width = 1;
666 } else if (spi->bits_per_word <= 16) {
667 chip->n_bytes = 2;
668 chip->dma_width = 2;
669 } else {
670 /* Never take >16b case for MRST SPIC */
671 dev_err(&spi->dev, "invalid wordsize\n");
672 return -EINVAL;
673 }
674 chip->bits_per_word = spi->bits_per_word;
675
676 if (!spi->max_speed_hz) {
677 dev_err(&spi->dev, "No max speed HZ parameter\n");
678 return -EINVAL;
679 }
680 chip->speed_hz = spi->max_speed_hz;
681
682 chip->tmode = 0; /* Tx & Rx */
683 /* Default SPI mode is SCPOL = 0, SCPH = 0 */
684 chip->cr0 = (chip->bits_per_word - 1)
685 | (chip->type << SPI_FRF_OFFSET)
686 | (spi->mode << SPI_MODE_OFFSET)
687 | (chip->tmode << SPI_TMOD_OFFSET);
688
689 spi_set_ctldata(spi, chip);
690 return 0;
691 }
692
693 static void dw_spi_cleanup(struct spi_device *spi)
694 {
695 struct chip_data *chip = spi_get_ctldata(spi);
696 kfree(chip);
697 }
698
699 static int __devinit init_queue(struct dw_spi *dws)
700 {
701 INIT_LIST_HEAD(&dws->queue);
702 spin_lock_init(&dws->lock);
703
704 dws->run = QUEUE_STOPPED;
705 dws->busy = 0;
706
707 tasklet_init(&dws->pump_transfers,
708 pump_transfers, (unsigned long)dws);
709
710 INIT_WORK(&dws->pump_messages, pump_messages);
711 dws->workqueue = create_singlethread_workqueue(
712 dev_name(dws->master->dev.parent));
713 if (dws->workqueue == NULL)
714 return -EBUSY;
715
716 return 0;
717 }
718
719 static int start_queue(struct dw_spi *dws)
720 {
721 unsigned long flags;
722
723 spin_lock_irqsave(&dws->lock, flags);
724
725 if (dws->run == QUEUE_RUNNING || dws->busy) {
726 spin_unlock_irqrestore(&dws->lock, flags);
727 return -EBUSY;
728 }
729
730 dws->run = QUEUE_RUNNING;
731 dws->cur_msg = NULL;
732 dws->cur_transfer = NULL;
733 dws->cur_chip = NULL;
734 dws->prev_chip = NULL;
735 spin_unlock_irqrestore(&dws->lock, flags);
736
737 queue_work(dws->workqueue, &dws->pump_messages);
738
739 return 0;
740 }
741
742 static int stop_queue(struct dw_spi *dws)
743 {
744 unsigned long flags;
745 unsigned limit = 50;
746 int status = 0;
747
748 spin_lock_irqsave(&dws->lock, flags);
749 dws->run = QUEUE_STOPPED;
750 while ((!list_empty(&dws->queue) || dws->busy) && limit--) {
751 spin_unlock_irqrestore(&dws->lock, flags);
752 msleep(10);
753 spin_lock_irqsave(&dws->lock, flags);
754 }
755
756 if (!list_empty(&dws->queue) || dws->busy)
757 status = -EBUSY;
758 spin_unlock_irqrestore(&dws->lock, flags);
759
760 return status;
761 }
762
763 static int destroy_queue(struct dw_spi *dws)
764 {
765 int status;
766
767 status = stop_queue(dws);
768 if (status != 0)
769 return status;
770 destroy_workqueue(dws->workqueue);
771 return 0;
772 }
773
774 /* Restart the controller, disable all interrupts, clean rx fifo */
775 static void spi_hw_init(struct dw_spi *dws)
776 {
777 spi_enable_chip(dws, 0);
778 spi_mask_intr(dws, 0xff);
779 spi_enable_chip(dws, 1);
780
781 /*
782 * Try to detect the FIFO depth if not set by interface driver,
783 * the depth could be from 2 to 256 from HW spec
784 */
785 if (!dws->fifo_len) {
786 u32 fifo;
787 for (fifo = 2; fifo <= 257; fifo++) {
788 dw_writew(dws, DW_SPI_TXFLTR, fifo);
789 if (fifo != dw_readw(dws, DW_SPI_TXFLTR))
790 break;
791 }
792
793 dws->fifo_len = (fifo == 257) ? 0 : fifo;
794 dw_writew(dws, DW_SPI_TXFLTR, 0);
795 }
796 }
797
798 int __devinit dw_spi_add_host(struct dw_spi *dws)
799 {
800 struct spi_master *master;
801 int ret;
802
803 BUG_ON(dws == NULL);
804
805 master = spi_alloc_master(dws->parent_dev, 0);
806 if (!master) {
807 ret = -ENOMEM;
808 goto exit;
809 }
810
811 dws->master = master;
812 dws->type = SSI_MOTO_SPI;
813 dws->prev_chip = NULL;
814 dws->dma_inited = 0;
815 dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
816 snprintf(dws->name, sizeof(dws->name), "dw_spi%d",
817 dws->bus_num);
818
819 ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
820 dws->name, dws);
821 if (ret < 0) {
822 dev_err(&master->dev, "can not get IRQ\n");
823 goto err_free_master;
824 }
825
826 master->mode_bits = SPI_CPOL | SPI_CPHA;
827 master->bus_num = dws->bus_num;
828 master->num_chipselect = dws->num_cs;
829 master->cleanup = dw_spi_cleanup;
830 master->setup = dw_spi_setup;
831 master->transfer = dw_spi_transfer;
832
833 /* Basic HW init */
834 spi_hw_init(dws);
835
836 if (dws->dma_ops && dws->dma_ops->dma_init) {
837 ret = dws->dma_ops->dma_init(dws);
838 if (ret) {
839 dev_warn(&master->dev, "DMA init failed\n");
840 dws->dma_inited = 0;
841 }
842 }
843
844 /* Initial and start queue */
845 ret = init_queue(dws);
846 if (ret) {
847 dev_err(&master->dev, "problem initializing queue\n");
848 goto err_diable_hw;
849 }
850 ret = start_queue(dws);
851 if (ret) {
852 dev_err(&master->dev, "problem starting queue\n");
853 goto err_diable_hw;
854 }
855
856 spi_master_set_devdata(master, dws);
857 ret = spi_register_master(master);
858 if (ret) {
859 dev_err(&master->dev, "problem registering spi master\n");
860 goto err_queue_alloc;
861 }
862
863 mrst_spi_debugfs_init(dws);
864 return 0;
865
866 err_queue_alloc:
867 destroy_queue(dws);
868 if (dws->dma_ops && dws->dma_ops->dma_exit)
869 dws->dma_ops->dma_exit(dws);
870 err_diable_hw:
871 spi_enable_chip(dws, 0);
872 free_irq(dws->irq, dws);
873 err_free_master:
874 spi_master_put(master);
875 exit:
876 return ret;
877 }
878 EXPORT_SYMBOL_GPL(dw_spi_add_host);
879
880 void __devexit dw_spi_remove_host(struct dw_spi *dws)
881 {
882 int status = 0;
883
884 if (!dws)
885 return;
886 mrst_spi_debugfs_remove(dws);
887
888 /* Remove the queue */
889 status = destroy_queue(dws);
890 if (status != 0)
891 dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
892 "complete, message memory not freed\n");
893
894 if (dws->dma_ops && dws->dma_ops->dma_exit)
895 dws->dma_ops->dma_exit(dws);
896 spi_enable_chip(dws, 0);
897 /* Disable clk */
898 spi_set_clk(dws, 0);
899 free_irq(dws->irq, dws);
900
901 /* Disconnect from the SPI framework */
902 spi_unregister_master(dws->master);
903 }
904 EXPORT_SYMBOL_GPL(dw_spi_remove_host);
905
906 int dw_spi_suspend_host(struct dw_spi *dws)
907 {
908 int ret = 0;
909
910 ret = stop_queue(dws);
911 if (ret)
912 return ret;
913 spi_enable_chip(dws, 0);
914 spi_set_clk(dws, 0);
915 return ret;
916 }
917 EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
918
919 int dw_spi_resume_host(struct dw_spi *dws)
920 {
921 int ret;
922
923 spi_hw_init(dws);
924 ret = start_queue(dws);
925 if (ret)
926 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
927 return ret;
928 }
929 EXPORT_SYMBOL_GPL(dw_spi_resume_host);
930
931 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
932 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
933 MODULE_LICENSE("GPL v2");
Linux kernel - Deliverables
This page took 0.051439 seconds and 5 git commands to generate.