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spi: dw: Fix dynamic speed change.
[linux-2.6/btrfs-unstable.git] / drivers / spi / spi-dw.c
blob332a6abd8cf30d5ee395bdfc6297c81526ece330
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
16 #include <linux/dma-mapping.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/highmem.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 #include <linux/spi/spi.h>
23 #include <linux/gpio.h>
24
25 #include "spi-dw.h"
26
27 #ifdef CONFIG_DEBUG_FS
28 #include <linux/debugfs.h>
29 #endif
30
31 #define START_STATE ((void *)0)
32 #define RUNNING_STATE ((void *)1)
33 #define DONE_STATE ((void *)2)
34 #define ERROR_STATE ((void *)-1)
35
36 /* Slave spi_dev related */
37 struct chip_data {
38 u16 cr0;
39 u8 cs; /* chip select pin */
40 u8 n_bytes; /* current is a 1/2/4 byte op */
41 u8 tmode; /* TR/TO/RO/EEPROM */
42 u8 type; /* SPI/SSP/MicroWire */
43
44 u8 poll_mode; /* 1 means use poll mode */
45
46 u32 dma_width;
47 u32 rx_threshold;
48 u32 tx_threshold;
49 u8 enable_dma;
50 u8 bits_per_word;
51 u16 clk_div; /* baud rate divider */
52 u32 speed_hz; /* baud rate */
53 void (*cs_control)(u32 command);
54 };
55
56 #ifdef CONFIG_DEBUG_FS
57 #define SPI_REGS_BUFSIZE 1024
58 static ssize_t dw_spi_show_regs(struct file *file, char __user *user_buf,
59 size_t count, loff_t *ppos)
60 {
61 struct dw_spi *dws = file->private_data;
62 char *buf;
63 u32 len = 0;
64 ssize_t ret;
65
66 buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
67 if (!buf)
68 return 0;
69
70 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
71 "%s registers:\n", dev_name(&dws->master->dev));
72 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
73 "=================================\n");
74 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
75 "CTRL0: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL0));
76 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
77 "CTRL1: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL1));
78 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
79 "SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR));
80 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
81 "SER: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SER));
82 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
83 "BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR));
84 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
85 "TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFLTR));
86 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
87 "RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFLTR));
88 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
89 "TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR));
90 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
91 "RXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_RXFLR));
92 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
93 "SR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SR));
94 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
95 "IMR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_IMR));
96 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
97 "ISR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_ISR));
98 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
99 "DMACR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_DMACR));
100 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
101 "DMATDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMATDLR));
102 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
103 "DMARDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMARDLR));
104 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
105 "=================================\n");
106
107 ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
108 kfree(buf);
109 return ret;
110 }
111
112 static const struct file_operations dw_spi_regs_ops = {
113 .owner = THIS_MODULE,
114 .open = simple_open,
115 .read = dw_spi_show_regs,
116 .llseek = default_llseek,
117 };
118
119 static int dw_spi_debugfs_init(struct dw_spi *dws)
120 {
121 dws->debugfs = debugfs_create_dir("dw_spi", NULL);
122 if (!dws->debugfs)
123 return -ENOMEM;
124
125 debugfs_create_file("registers", S_IFREG | S_IRUGO,
126 dws->debugfs, (void *)dws, &dw_spi_regs_ops);
127 return 0;
128 }
129
130 static void dw_spi_debugfs_remove(struct dw_spi *dws)
131 {
132 debugfs_remove_recursive(dws->debugfs);
133 }
134
135 #else
136 static inline int dw_spi_debugfs_init(struct dw_spi *dws)
137 {
138 return 0;
139 }
140
141 static inline void dw_spi_debugfs_remove(struct dw_spi *dws)
142 {
143 }
144 #endif /* CONFIG_DEBUG_FS */
145
146 /* Return the max entries we can fill into tx fifo */
147 static inline u32 tx_max(struct dw_spi *dws)
148 {
149 u32 tx_left, tx_room, rxtx_gap;
150
151 tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
152 tx_room = dws->fifo_len - dw_readw(dws, DW_SPI_TXFLR);
153
154 /*
155 * Another concern is about the tx/rx mismatch, we
156 * though to use (dws->fifo_len - rxflr - txflr) as
157 * one maximum value for tx, but it doesn't cover the
158 * data which is out of tx/rx fifo and inside the
159 * shift registers. So a control from sw point of
160 * view is taken.
161 */
162 rxtx_gap = ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
163 / dws->n_bytes;
164
165 return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
166 }
167
168 /* Return the max entries we should read out of rx fifo */
169 static inline u32 rx_max(struct dw_spi *dws)
170 {
171 u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
172
173 return min_t(u32, rx_left, dw_readw(dws, DW_SPI_RXFLR));
174 }
175
176 static void dw_writer(struct dw_spi *dws)
177 {
178 u32 max = tx_max(dws);
179 u16 txw = 0;
180
181 while (max--) {
182 /* Set the tx word if the transfer's original "tx" is not null */
183 if (dws->tx_end - dws->len) {
184 if (dws->n_bytes == 1)
185 txw = *(u8 *)(dws->tx);
186 else
187 txw = *(u16 *)(dws->tx);
188 }
189 dw_writew(dws, DW_SPI_DR, txw);
190 dws->tx += dws->n_bytes;
191 }
192 }
193
194 static void dw_reader(struct dw_spi *dws)
195 {
196 u32 max = rx_max(dws);
197 u16 rxw;
198
199 while (max--) {
200 rxw = dw_readw(dws, DW_SPI_DR);
201 /* Care rx only if the transfer's original "rx" is not null */
202 if (dws->rx_end - dws->len) {
203 if (dws->n_bytes == 1)
204 *(u8 *)(dws->rx) = rxw;
205 else
206 *(u16 *)(dws->rx) = rxw;
207 }
208 dws->rx += dws->n_bytes;
209 }
210 }
211
212 static void *next_transfer(struct dw_spi *dws)
213 {
214 struct spi_message *msg = dws->cur_msg;
215 struct spi_transfer *trans = dws->cur_transfer;
216
217 /* Move to next transfer */
218 if (trans->transfer_list.next != &msg->transfers) {
219 dws->cur_transfer =
220 list_entry(trans->transfer_list.next,
221 struct spi_transfer,
222 transfer_list);
223 return RUNNING_STATE;
224 }
225
226 return DONE_STATE;
227 }
228
229 /*
230 * Note: first step is the protocol driver prepares
231 * a dma-capable memory, and this func just need translate
232 * the virt addr to physical
233 */
234 static int map_dma_buffers(struct dw_spi *dws)
235 {
236 if (!dws->cur_msg->is_dma_mapped
237 || !dws->dma_inited
238 || !dws->cur_chip->enable_dma
239 || !dws->dma_ops)
240 return 0;
241
242 if (dws->cur_transfer->tx_dma)
243 dws->tx_dma = dws->cur_transfer->tx_dma;
244
245 if (dws->cur_transfer->rx_dma)
246 dws->rx_dma = dws->cur_transfer->rx_dma;
247
248 return 1;
249 }
250
251 /* Caller already set message->status; dma and pio irqs are blocked */
252 static void giveback(struct dw_spi *dws)
253 {
254 struct spi_transfer *last_transfer;
255 struct spi_message *msg;
256
257 msg = dws->cur_msg;
258 dws->cur_msg = NULL;
259 dws->cur_transfer = NULL;
260 dws->prev_chip = dws->cur_chip;
261 dws->cur_chip = NULL;
262 dws->dma_mapped = 0;
263
264 last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
265 transfer_list);
266
267 if (!last_transfer->cs_change)
268 spi_chip_sel(dws, msg->spi, 0);
269
270 spi_finalize_current_message(dws->master);
271 }
272
273 static void int_error_stop(struct dw_spi *dws, const char *msg)
274 {
275 /* Stop the hw */
276 spi_enable_chip(dws, 0);
277
278 dev_err(&dws->master->dev, "%s\n", msg);
279 dws->cur_msg->state = ERROR_STATE;
280 tasklet_schedule(&dws->pump_transfers);
281 }
282
283 void dw_spi_xfer_done(struct dw_spi *dws)
284 {
285 /* Update total byte transferred return count actual bytes read */
286 dws->cur_msg->actual_length += dws->len;
287
288 /* Move to next transfer */
289 dws->cur_msg->state = next_transfer(dws);
290
291 /* Handle end of message */
292 if (dws->cur_msg->state == DONE_STATE) {
293 dws->cur_msg->status = 0;
294 giveback(dws);
295 } else
296 tasklet_schedule(&dws->pump_transfers);
297 }
298 EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
299
300 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
301 {
302 u16 irq_status = dw_readw(dws, DW_SPI_ISR);
303
304 /* Error handling */
305 if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
306 dw_readw(dws, DW_SPI_TXOICR);
307 dw_readw(dws, DW_SPI_RXOICR);
308 dw_readw(dws, DW_SPI_RXUICR);
309 int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
310 return IRQ_HANDLED;
311 }
312
313 dw_reader(dws);
314 if (dws->rx_end == dws->rx) {
315 spi_mask_intr(dws, SPI_INT_TXEI);
316 dw_spi_xfer_done(dws);
317 return IRQ_HANDLED;
318 }
319 if (irq_status & SPI_INT_TXEI) {
320 spi_mask_intr(dws, SPI_INT_TXEI);
321 dw_writer(dws);
322 /* Enable TX irq always, it will be disabled when RX finished */
323 spi_umask_intr(dws, SPI_INT_TXEI);
324 }
325
326 return IRQ_HANDLED;
327 }
328
329 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
330 {
331 struct dw_spi *dws = dev_id;
332 u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f;
333
334 if (!irq_status)
335 return IRQ_NONE;
336
337 if (!dws->cur_msg) {
338 spi_mask_intr(dws, SPI_INT_TXEI);
339 return IRQ_HANDLED;
340 }
341
342 return dws->transfer_handler(dws);
343 }
344
345 /* Must be called inside pump_transfers() */
346 static void poll_transfer(struct dw_spi *dws)
347 {
348 do {
349 dw_writer(dws);
350 dw_reader(dws);
351 cpu_relax();
352 } while (dws->rx_end > dws->rx);
353
354 dw_spi_xfer_done(dws);
355 }
356
357 static void pump_transfers(unsigned long data)
358 {
359 struct dw_spi *dws = (struct dw_spi *)data;
360 struct spi_message *message = NULL;
361 struct spi_transfer *transfer = NULL;
362 struct spi_transfer *previous = NULL;
363 struct spi_device *spi = NULL;
364 struct chip_data *chip = NULL;
365 u8 bits = 0;
366 u8 imask = 0;
367 u8 cs_change = 0;
368 u16 txint_level = 0;
369 u16 clk_div = 0;
370 u32 speed = 0;
371 u32 cr0 = 0;
372
373 /* Get current state information */
374 message = dws->cur_msg;
375 transfer = dws->cur_transfer;
376 chip = dws->cur_chip;
377 spi = message->spi;
378
379 if (message->state == ERROR_STATE) {
380 message->status = -EIO;
381 goto early_exit;
382 }
383
384 /* Handle end of message */
385 if (message->state == DONE_STATE) {
386 message->status = 0;
387 goto early_exit;
388 }
389
390 /* Delay if requested at end of transfer */
391 if (message->state == RUNNING_STATE) {
392 previous = list_entry(transfer->transfer_list.prev,
393 struct spi_transfer,
394 transfer_list);
395 if (previous->delay_usecs)
396 udelay(previous->delay_usecs);
397 }
398
399 dws->n_bytes = chip->n_bytes;
400 dws->dma_width = chip->dma_width;
401 dws->cs_control = chip->cs_control;
402
403 dws->rx_dma = transfer->rx_dma;
404 dws->tx_dma = transfer->tx_dma;
405 dws->tx = (void *)transfer->tx_buf;
406 dws->tx_end = dws->tx + transfer->len;
407 dws->rx = transfer->rx_buf;
408 dws->rx_end = dws->rx + transfer->len;
409 dws->len = dws->cur_transfer->len;
410 if (chip != dws->prev_chip)
411 cs_change = 1;
412
413 cr0 = chip->cr0;
414
415 /* Handle per transfer options for bpw and speed */
416 if (transfer->speed_hz) {
417 speed = chip->speed_hz;
418
419 if ((transfer->speed_hz != speed) || (!chip->clk_div)) {
420 speed = transfer->speed_hz;
421
422 /* clk_div doesn't support odd number */
423 clk_div = dws->max_freq / speed;
424 clk_div = (clk_div + 1) & 0xfffe;
425
426 chip->speed_hz = speed;
427 chip->clk_div = clk_div;
428 }
429 }
430 if (transfer->bits_per_word) {
431 bits = transfer->bits_per_word;
432 dws->n_bytes = dws->dma_width = bits >> 3;
433 cr0 = (bits - 1)
434 | (chip->type << SPI_FRF_OFFSET)
435 | (spi->mode << SPI_MODE_OFFSET)
436 | (chip->tmode << SPI_TMOD_OFFSET);
437 }
438 message->state = RUNNING_STATE;
439
440 /*
441 * Adjust transfer mode if necessary. Requires platform dependent
442 * chipselect mechanism.
443 */
444 if (dws->cs_control) {
445 if (dws->rx && dws->tx)
446 chip->tmode = SPI_TMOD_TR;
447 else if (dws->rx)
448 chip->tmode = SPI_TMOD_RO;
449 else
450 chip->tmode = SPI_TMOD_TO;
451
452 cr0 &= ~SPI_TMOD_MASK;
453 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
454 }
455
456 /* Check if current transfer is a DMA transaction */
457 dws->dma_mapped = map_dma_buffers(dws);
458
459 /*
460 * Interrupt mode
461 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
462 */
463 if (!dws->dma_mapped && !chip->poll_mode) {
464 int templen = dws->len / dws->n_bytes;
465
466 txint_level = dws->fifo_len / 2;
467 txint_level = (templen > txint_level) ? txint_level : templen;
468
469 imask |= SPI_INT_TXEI | SPI_INT_TXOI |
470 SPI_INT_RXUI | SPI_INT_RXOI;
471 dws->transfer_handler = interrupt_transfer;
472 }
473
474 /*
475 * Reprogram registers only if
476 * 1. chip select changes
477 * 2. clk_div is changed
478 * 3. control value changes
479 */
480 if (dw_readw(dws, DW_SPI_CTRL0) != cr0 || cs_change || clk_div || imask) {
481 spi_enable_chip(dws, 0);
482
483 if (dw_readw(dws, DW_SPI_CTRL0) != cr0)
484 dw_writew(dws, DW_SPI_CTRL0, cr0);
485
486 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
487 spi_chip_sel(dws, spi, 1);
488
489 /* Set the interrupt mask, for poll mode just disable all int */
490 spi_mask_intr(dws, 0xff);
491 if (imask)
492 spi_umask_intr(dws, imask);
493 if (txint_level)
494 dw_writew(dws, DW_SPI_TXFLTR, txint_level);
495
496 spi_enable_chip(dws, 1);
497 if (cs_change)
498 dws->prev_chip = chip;
499 }
500
501 if (dws->dma_mapped)
502 dws->dma_ops->dma_transfer(dws, cs_change);
503
504 if (chip->poll_mode)
505 poll_transfer(dws);
506
507 return;
508
509 early_exit:
510 giveback(dws);
511 }
512
513 static int dw_spi_transfer_one_message(struct spi_master *master,
514 struct spi_message *msg)
515 {
516 struct dw_spi *dws = spi_master_get_devdata(master);
517
518 dws->cur_msg = msg;
519 /* Initial message state */
520 dws->cur_msg->state = START_STATE;
521 dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
522 struct spi_transfer,
523 transfer_list);
524 dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
525
526 /* Launch transfers */
527 tasklet_schedule(&dws->pump_transfers);
528
529 return 0;
530 }
531
532 /* This may be called twice for each spi dev */
533 static int dw_spi_setup(struct spi_device *spi)
534 {
535 struct dw_spi_chip *chip_info = NULL;
536 struct chip_data *chip;
537 int ret;
538
539 /* Only alloc on first setup */
540 chip = spi_get_ctldata(spi);
541 if (!chip) {
542 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
543 if (!chip)
544 return -ENOMEM;
545 spi_set_ctldata(spi, chip);
546 }
547
548 /*
549 * Protocol drivers may change the chip settings, so...
550 * if chip_info exists, use it
551 */
552 chip_info = spi->controller_data;
553
554 /* chip_info doesn't always exist */
555 if (chip_info) {
556 if (chip_info->cs_control)
557 chip->cs_control = chip_info->cs_control;
558
559 chip->poll_mode = chip_info->poll_mode;
560 chip->type = chip_info->type;
561
562 chip->rx_threshold = 0;
563 chip->tx_threshold = 0;
564
565 chip->enable_dma = chip_info->enable_dma;
566 }
567
568 if (spi->bits_per_word == 8) {
569 chip->n_bytes = 1;
570 chip->dma_width = 1;
571 } else if (spi->bits_per_word == 16) {
572 chip->n_bytes = 2;
573 chip->dma_width = 2;
574 }
575 chip->bits_per_word = spi->bits_per_word;
576
577 if (!spi->max_speed_hz) {
578 dev_err(&spi->dev, "No max speed HZ parameter\n");
579 return -EINVAL;
580 }
581
582 chip->tmode = 0; /* Tx & Rx */
583 /* Default SPI mode is SCPOL = 0, SCPH = 0 */
584 chip->cr0 = (chip->bits_per_word - 1)
585 | (chip->type << SPI_FRF_OFFSET)
586 | (spi->mode << SPI_MODE_OFFSET)
587 | (chip->tmode << SPI_TMOD_OFFSET);
588
589 if (spi->mode & SPI_LOOP)
590 chip->cr0 |= 1 << SPI_SRL_OFFSET;
591
592 if (gpio_is_valid(spi->cs_gpio)) {
593 ret = gpio_direction_output(spi->cs_gpio,
594 !(spi->mode & SPI_CS_HIGH));
595 if (ret)
596 return ret;
597 }
598
599 return 0;
600 }
601
602 static void dw_spi_cleanup(struct spi_device *spi)
603 {
604 struct chip_data *chip = spi_get_ctldata(spi);
605
606 kfree(chip);
607 spi_set_ctldata(spi, NULL);
608 }
609
610 /* Restart the controller, disable all interrupts, clean rx fifo */
611 static void spi_hw_init(struct dw_spi *dws)
612 {
613 spi_enable_chip(dws, 0);
614 spi_mask_intr(dws, 0xff);
615 spi_enable_chip(dws, 1);
616
617 /*
618 * Try to detect the FIFO depth if not set by interface driver,
619 * the depth could be from 2 to 256 from HW spec
620 */
621 if (!dws->fifo_len) {
622 u32 fifo;
623
624 for (fifo = 2; fifo <= 257; fifo++) {
625 dw_writew(dws, DW_SPI_TXFLTR, fifo);
626 if (fifo != dw_readw(dws, DW_SPI_TXFLTR))
627 break;
628 }
629
630 dws->fifo_len = (fifo == 257) ? 0 : fifo;
631 dw_writew(dws, DW_SPI_TXFLTR, 0);
632 }
633 }
634
635 int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
636 {
637 struct spi_master *master;
638 int ret;
639
640 BUG_ON(dws == NULL);
641
642 master = spi_alloc_master(dev, 0);
643 if (!master)
644 return -ENOMEM;
645
646 dws->master = master;
647 dws->type = SSI_MOTO_SPI;
648 dws->prev_chip = NULL;
649 dws->dma_inited = 0;
650 dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
651 snprintf(dws->name, sizeof(dws->name), "dw_spi%d", dws->bus_num);
652
653 ret = devm_request_irq(dev, dws->irq, dw_spi_irq, IRQF_SHARED,
654 dws->name, dws);
655 if (ret < 0) {
656 dev_err(&master->dev, "can not get IRQ\n");
657 goto err_free_master;
658 }
659
660 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
661 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
662 master->bus_num = dws->bus_num;
663 master->num_chipselect = dws->num_cs;
664 master->setup = dw_spi_setup;
665 master->cleanup = dw_spi_cleanup;
666 master->transfer_one_message = dw_spi_transfer_one_message;
667 master->max_speed_hz = dws->max_freq;
668
669 /* Basic HW init */
670 spi_hw_init(dws);
671
672 if (dws->dma_ops && dws->dma_ops->dma_init) {
673 ret = dws->dma_ops->dma_init(dws);
674 if (ret) {
675 dev_warn(&master->dev, "DMA init failed\n");
676 dws->dma_inited = 0;
677 }
678 }
679
680 tasklet_init(&dws->pump_transfers, pump_transfers, (unsigned long)dws);
681
682 spi_master_set_devdata(master, dws);
683 ret = devm_spi_register_master(dev, master);
684 if (ret) {
685 dev_err(&master->dev, "problem registering spi master\n");
686 goto err_dma_exit;
687 }
688
689 dw_spi_debugfs_init(dws);
690 return 0;
691
692 err_dma_exit:
693 if (dws->dma_ops && dws->dma_ops->dma_exit)
694 dws->dma_ops->dma_exit(dws);
695 spi_enable_chip(dws, 0);
696 err_free_master:
697 spi_master_put(master);
698 return ret;
699 }
700 EXPORT_SYMBOL_GPL(dw_spi_add_host);
701
702 void dw_spi_remove_host(struct dw_spi *dws)
703 {
704 if (!dws)
705 return;
706 dw_spi_debugfs_remove(dws);
707
708 if (dws->dma_ops && dws->dma_ops->dma_exit)
709 dws->dma_ops->dma_exit(dws);
710 spi_enable_chip(dws, 0);
711 /* Disable clk */
712 spi_set_clk(dws, 0);
713 }
714 EXPORT_SYMBOL_GPL(dw_spi_remove_host);
715
716 int dw_spi_suspend_host(struct dw_spi *dws)
717 {
718 int ret = 0;
719
720 ret = spi_master_suspend(dws->master);
721 if (ret)
722 return ret;
723 spi_enable_chip(dws, 0);
724 spi_set_clk(dws, 0);
725 return ret;
726 }
727 EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
728
729 int dw_spi_resume_host(struct dw_spi *dws)
730 {
731 int ret;
732
733 spi_hw_init(dws);
734 ret = spi_master_resume(dws->master);
735 if (ret)
736 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
737 return ret;
738 }
739 EXPORT_SYMBOL_GPL(dw_spi_resume_host);
740
741 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
742 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
743 MODULE_LICENSE("GPL v2");
(deprecated) Btrfs devel tree