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neigh: Remove by-hand SKB queue handling.
[linux-2.6/mini2440.git] / drivers / spi / omap2_mcspi.c
blob9d2186fd74aaf7eaca9f9954dde88d1dc11e7c36
1 /*
2 * OMAP2 McSPI controller driver
3 *
4 * Copyright (C) 2005, 2006 Nokia Corporation
5 * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
6 * Juha Yrjölä <juha.yrjola@nokia.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24 #include <linux/kernel.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/device.h>
29 #include <linux/delay.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/platform_device.h>
32 #include <linux/err.h>
33 #include <linux/clk.h>
34 #include <linux/io.h>
35
36 #include <linux/spi/spi.h>
37
38 #include <mach/dma.h>
39 #include <mach/clock.h>
40
41
42 #define OMAP2_MCSPI_MAX_FREQ 48000000
43
44 #define OMAP2_MCSPI_REVISION 0x00
45 #define OMAP2_MCSPI_SYSCONFIG 0x10
46 #define OMAP2_MCSPI_SYSSTATUS 0x14
47 #define OMAP2_MCSPI_IRQSTATUS 0x18
48 #define OMAP2_MCSPI_IRQENABLE 0x1c
49 #define OMAP2_MCSPI_WAKEUPENABLE 0x20
50 #define OMAP2_MCSPI_SYST 0x24
51 #define OMAP2_MCSPI_MODULCTRL 0x28
52
53 /* per-channel banks, 0x14 bytes each, first is: */
54 #define OMAP2_MCSPI_CHCONF0 0x2c
55 #define OMAP2_MCSPI_CHSTAT0 0x30
56 #define OMAP2_MCSPI_CHCTRL0 0x34
57 #define OMAP2_MCSPI_TX0 0x38
58 #define OMAP2_MCSPI_RX0 0x3c
59
60 /* per-register bitmasks: */
61
62 #define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE (1 << 0)
63 #define OMAP2_MCSPI_SYSCONFIG_SOFTRESET (1 << 1)
64
65 #define OMAP2_MCSPI_SYSSTATUS_RESETDONE (1 << 0)
66
67 #define OMAP2_MCSPI_MODULCTRL_SINGLE (1 << 0)
68 #define OMAP2_MCSPI_MODULCTRL_MS (1 << 2)
69 #define OMAP2_MCSPI_MODULCTRL_STEST (1 << 3)
70
71 #define OMAP2_MCSPI_CHCONF_PHA (1 << 0)
72 #define OMAP2_MCSPI_CHCONF_POL (1 << 1)
73 #define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
74 #define OMAP2_MCSPI_CHCONF_EPOL (1 << 6)
75 #define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
76 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY (0x01 << 12)
77 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY (0x02 << 12)
78 #define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
79 #define OMAP2_MCSPI_CHCONF_DMAW (1 << 14)
80 #define OMAP2_MCSPI_CHCONF_DMAR (1 << 15)
81 #define OMAP2_MCSPI_CHCONF_DPE0 (1 << 16)
82 #define OMAP2_MCSPI_CHCONF_DPE1 (1 << 17)
83 #define OMAP2_MCSPI_CHCONF_IS (1 << 18)
84 #define OMAP2_MCSPI_CHCONF_TURBO (1 << 19)
85 #define OMAP2_MCSPI_CHCONF_FORCE (1 << 20)
86
87 #define OMAP2_MCSPI_CHSTAT_RXS (1 << 0)
88 #define OMAP2_MCSPI_CHSTAT_TXS (1 << 1)
89 #define OMAP2_MCSPI_CHSTAT_EOT (1 << 2)
90
91 #define OMAP2_MCSPI_CHCTRL_EN (1 << 0)
92
93
94 /* We have 2 DMA channels per CS, one for RX and one for TX */
95 struct omap2_mcspi_dma {
96 int dma_tx_channel;
97 int dma_rx_channel;
98
99 int dma_tx_sync_dev;
100 int dma_rx_sync_dev;
101
102 struct completion dma_tx_completion;
103 struct completion dma_rx_completion;
104 };
105
106 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
107 * cache operations; better heuristics consider wordsize and bitrate.
108 */
109 #define DMA_MIN_BYTES 8
110
111
112 struct omap2_mcspi {
113 struct work_struct work;
114 /* lock protects queue and registers */
115 spinlock_t lock;
116 struct list_head msg_queue;
117 struct spi_master *master;
118 struct clk *ick;
119 struct clk *fck;
120 /* Virtual base address of the controller */
121 void __iomem *base;
122 /* SPI1 has 4 channels, while SPI2 has 2 */
123 struct omap2_mcspi_dma *dma_channels;
124 };
125
126 struct omap2_mcspi_cs {
127 void __iomem *base;
128 int word_len;
129 };
130
131 static struct workqueue_struct *omap2_mcspi_wq;
132
133 #define MOD_REG_BIT(val, mask, set) do { \
134 if (set) \
135 val |= mask; \
136 else \
137 val &= ~mask; \
138 } while (0)
139
140 static inline void mcspi_write_reg(struct spi_master *master,
141 int idx, u32 val)
142 {
143 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
144
145 __raw_writel(val, mcspi->base + idx);
146 }
147
148 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
149 {
150 struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
151
152 return __raw_readl(mcspi->base + idx);
153 }
154
155 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
156 int idx, u32 val)
157 {
158 struct omap2_mcspi_cs *cs = spi->controller_state;
159
160 __raw_writel(val, cs->base + idx);
161 }
162
163 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
164 {
165 struct omap2_mcspi_cs *cs = spi->controller_state;
166
167 return __raw_readl(cs->base + idx);
168 }
169
170 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
171 int is_read, int enable)
172 {
173 u32 l, rw;
174
175 l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
176
177 if (is_read) /* 1 is read, 0 write */
178 rw = OMAP2_MCSPI_CHCONF_DMAR;
179 else
180 rw = OMAP2_MCSPI_CHCONF_DMAW;
181
182 MOD_REG_BIT(l, rw, enable);
183 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
184 }
185
186 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
187 {
188 u32 l;
189
190 l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
191 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
192 }
193
194 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
195 {
196 u32 l;
197
198 l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
199 MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
200 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
201 }
202
203 static void omap2_mcspi_set_master_mode(struct spi_master *master)
204 {
205 u32 l;
206
207 /* setup when switching from (reset default) slave mode
208 * to single-channel master mode
209 */
210 l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
211 MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
212 MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
213 MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
214 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
215 }
216
217 static unsigned
218 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
219 {
220 struct omap2_mcspi *mcspi;
221 struct omap2_mcspi_cs *cs = spi->controller_state;
222 struct omap2_mcspi_dma *mcspi_dma;
223 unsigned int count, c;
224 unsigned long base, tx_reg, rx_reg;
225 int word_len, data_type, element_count;
226 u8 * rx;
227 const u8 * tx;
228
229 mcspi = spi_master_get_devdata(spi->master);
230 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
231
232 count = xfer->len;
233 c = count;
234 word_len = cs->word_len;
235
236 base = (unsigned long) io_v2p(cs->base);
237 tx_reg = base + OMAP2_MCSPI_TX0;
238 rx_reg = base + OMAP2_MCSPI_RX0;
239 rx = xfer->rx_buf;
240 tx = xfer->tx_buf;
241
242 if (word_len <= 8) {
243 data_type = OMAP_DMA_DATA_TYPE_S8;
244 element_count = count;
245 } else if (word_len <= 16) {
246 data_type = OMAP_DMA_DATA_TYPE_S16;
247 element_count = count >> 1;
248 } else /* word_len <= 32 */ {
249 data_type = OMAP_DMA_DATA_TYPE_S32;
250 element_count = count >> 2;
251 }
252
253 if (tx != NULL) {
254 omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
255 data_type, element_count, 1,
256 OMAP_DMA_SYNC_ELEMENT,
257 mcspi_dma->dma_tx_sync_dev, 0);
258
259 omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
260 OMAP_DMA_AMODE_CONSTANT,
261 tx_reg, 0, 0);
262
263 omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
264 OMAP_DMA_AMODE_POST_INC,
265 xfer->tx_dma, 0, 0);
266 }
267
268 if (rx != NULL) {
269 omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
270 data_type, element_count, 1,
271 OMAP_DMA_SYNC_ELEMENT,
272 mcspi_dma->dma_rx_sync_dev, 1);
273
274 omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
275 OMAP_DMA_AMODE_CONSTANT,
276 rx_reg, 0, 0);
277
278 omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
279 OMAP_DMA_AMODE_POST_INC,
280 xfer->rx_dma, 0, 0);
281 }
282
283 if (tx != NULL) {
284 omap_start_dma(mcspi_dma->dma_tx_channel);
285 omap2_mcspi_set_dma_req(spi, 0, 1);
286 }
287
288 if (rx != NULL) {
289 omap_start_dma(mcspi_dma->dma_rx_channel);
290 omap2_mcspi_set_dma_req(spi, 1, 1);
291 }
292
293 if (tx != NULL) {
294 wait_for_completion(&mcspi_dma->dma_tx_completion);
295 dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE);
296 }
297
298 if (rx != NULL) {
299 wait_for_completion(&mcspi_dma->dma_rx_completion);
300 dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
301 }
302 return count;
303 }
304
305 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
306 {
307 unsigned long timeout;
308
309 timeout = jiffies + msecs_to_jiffies(1000);
310 while (!(__raw_readl(reg) & bit)) {
311 if (time_after(jiffies, timeout))
312 return -1;
313 cpu_relax();
314 }
315 return 0;
316 }
317
318 static unsigned
319 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
320 {
321 struct omap2_mcspi *mcspi;
322 struct omap2_mcspi_cs *cs = spi->controller_state;
323 unsigned int count, c;
324 u32 l;
325 void __iomem *base = cs->base;
326 void __iomem *tx_reg;
327 void __iomem *rx_reg;
328 void __iomem *chstat_reg;
329 int word_len;
330
331 mcspi = spi_master_get_devdata(spi->master);
332 count = xfer->len;
333 c = count;
334 word_len = cs->word_len;
335
336 l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
337 l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
338
339 /* We store the pre-calculated register addresses on stack to speed
340 * up the transfer loop. */
341 tx_reg = base + OMAP2_MCSPI_TX0;
342 rx_reg = base + OMAP2_MCSPI_RX0;
343 chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
344
345 if (word_len <= 8) {
346 u8 *rx;
347 const u8 *tx;
348
349 rx = xfer->rx_buf;
350 tx = xfer->tx_buf;
351
352 do {
353 c -= 1;
354 if (tx != NULL) {
355 if (mcspi_wait_for_reg_bit(chstat_reg,
356 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
357 dev_err(&spi->dev, "TXS timed out\n");
358 goto out;
359 }
360 #ifdef VERBOSE
361 dev_dbg(&spi->dev, "write-%d %02x\n",
362 word_len, *tx);
363 #endif
364 __raw_writel(*tx++, tx_reg);
365 }
366 if (rx != NULL) {
367 if (mcspi_wait_for_reg_bit(chstat_reg,
368 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
369 dev_err(&spi->dev, "RXS timed out\n");
370 goto out;
371 }
372 /* prevent last RX_ONLY read from triggering
373 * more word i/o: switch to rx+tx
374 */
375 if (c == 0 && tx == NULL)
376 mcspi_write_cs_reg(spi,
377 OMAP2_MCSPI_CHCONF0, l);
378 *rx++ = __raw_readl(rx_reg);
379 #ifdef VERBOSE
380 dev_dbg(&spi->dev, "read-%d %02x\n",
381 word_len, *(rx - 1));
382 #endif
383 }
384 } while (c);
385 } else if (word_len <= 16) {
386 u16 *rx;
387 const u16 *tx;
388
389 rx = xfer->rx_buf;
390 tx = xfer->tx_buf;
391 do {
392 c -= 2;
393 if (tx != NULL) {
394 if (mcspi_wait_for_reg_bit(chstat_reg,
395 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
396 dev_err(&spi->dev, "TXS timed out\n");
397 goto out;
398 }
399 #ifdef VERBOSE
400 dev_dbg(&spi->dev, "write-%d %04x\n",
401 word_len, *tx);
402 #endif
403 __raw_writel(*tx++, tx_reg);
404 }
405 if (rx != NULL) {
406 if (mcspi_wait_for_reg_bit(chstat_reg,
407 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
408 dev_err(&spi->dev, "RXS timed out\n");
409 goto out;
410 }
411 /* prevent last RX_ONLY read from triggering
412 * more word i/o: switch to rx+tx
413 */
414 if (c == 0 && tx == NULL)
415 mcspi_write_cs_reg(spi,
416 OMAP2_MCSPI_CHCONF0, l);
417 *rx++ = __raw_readl(rx_reg);
418 #ifdef VERBOSE
419 dev_dbg(&spi->dev, "read-%d %04x\n",
420 word_len, *(rx - 1));
421 #endif
422 }
423 } while (c);
424 } else if (word_len <= 32) {
425 u32 *rx;
426 const u32 *tx;
427
428 rx = xfer->rx_buf;
429 tx = xfer->tx_buf;
430 do {
431 c -= 4;
432 if (tx != NULL) {
433 if (mcspi_wait_for_reg_bit(chstat_reg,
434 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
435 dev_err(&spi->dev, "TXS timed out\n");
436 goto out;
437 }
438 #ifdef VERBOSE
439 dev_dbg(&spi->dev, "write-%d %04x\n",
440 word_len, *tx);
441 #endif
442 __raw_writel(*tx++, tx_reg);
443 }
444 if (rx != NULL) {
445 if (mcspi_wait_for_reg_bit(chstat_reg,
446 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
447 dev_err(&spi->dev, "RXS timed out\n");
448 goto out;
449 }
450 /* prevent last RX_ONLY read from triggering
451 * more word i/o: switch to rx+tx
452 */
453 if (c == 0 && tx == NULL)
454 mcspi_write_cs_reg(spi,
455 OMAP2_MCSPI_CHCONF0, l);
456 *rx++ = __raw_readl(rx_reg);
457 #ifdef VERBOSE
458 dev_dbg(&spi->dev, "read-%d %04x\n",
459 word_len, *(rx - 1));
460 #endif
461 }
462 } while (c);
463 }
464
465 /* for TX_ONLY mode, be sure all words have shifted out */
466 if (xfer->rx_buf == NULL) {
467 if (mcspi_wait_for_reg_bit(chstat_reg,
468 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
469 dev_err(&spi->dev, "TXS timed out\n");
470 } else if (mcspi_wait_for_reg_bit(chstat_reg,
471 OMAP2_MCSPI_CHSTAT_EOT) < 0)
472 dev_err(&spi->dev, "EOT timed out\n");
473 }
474 out:
475 return count - c;
476 }
477
478 /* called only when no transfer is active to this device */
479 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
480 struct spi_transfer *t)
481 {
482 struct omap2_mcspi_cs *cs = spi->controller_state;
483 struct omap2_mcspi *mcspi;
484 u32 l = 0, div = 0;
485 u8 word_len = spi->bits_per_word;
486
487 mcspi = spi_master_get_devdata(spi->master);
488
489 if (t != NULL && t->bits_per_word)
490 word_len = t->bits_per_word;
491
492 cs->word_len = word_len;
493
494 if (spi->max_speed_hz) {
495 while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
496 > spi->max_speed_hz)
497 div++;
498 } else
499 div = 15;
500
501 l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
502
503 /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
504 * REVISIT: this controller could support SPI_3WIRE mode.
505 */
506 l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
507 l |= OMAP2_MCSPI_CHCONF_DPE0;
508
509 /* wordlength */
510 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
511 l |= (word_len - 1) << 7;
512
513 /* set chipselect polarity; manage with FORCE */
514 if (!(spi->mode & SPI_CS_HIGH))
515 l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
516 else
517 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
518
519 /* set clock divisor */
520 l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
521 l |= div << 2;
522
523 /* set SPI mode 0..3 */
524 if (spi->mode & SPI_CPOL)
525 l |= OMAP2_MCSPI_CHCONF_POL;
526 else
527 l &= ~OMAP2_MCSPI_CHCONF_POL;
528 if (spi->mode & SPI_CPHA)
529 l |= OMAP2_MCSPI_CHCONF_PHA;
530 else
531 l &= ~OMAP2_MCSPI_CHCONF_PHA;
532
533 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
534
535 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
536 OMAP2_MCSPI_MAX_FREQ / (1 << div),
537 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
538 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
539
540 return 0;
541 }
542
543 static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
544 {
545 struct spi_device *spi = data;
546 struct omap2_mcspi *mcspi;
547 struct omap2_mcspi_dma *mcspi_dma;
548
549 mcspi = spi_master_get_devdata(spi->master);
550 mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
551
552 complete(&mcspi_dma->dma_rx_completion);
553
554 /* We must disable the DMA RX request */
555 omap2_mcspi_set_dma_req(spi, 1, 0);
556 }
557
558 static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
559 {
560 struct spi_device *spi = data;
561 struct omap2_mcspi *mcspi;
562 struct omap2_mcspi_dma *mcspi_dma;
563
564 mcspi = spi_master_get_devdata(spi->master);
565 mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
566
567 complete(&mcspi_dma->dma_tx_completion);
568
569 /* We must disable the DMA TX request */
570 omap2_mcspi_set_dma_req(spi, 0, 0);
571 }
572
573 static int omap2_mcspi_request_dma(struct spi_device *spi)
574 {
575 struct spi_master *master = spi->master;
576 struct omap2_mcspi *mcspi;
577 struct omap2_mcspi_dma *mcspi_dma;
578
579 mcspi = spi_master_get_devdata(master);
580 mcspi_dma = mcspi->dma_channels + spi->chip_select;
581
582 if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
583 omap2_mcspi_dma_rx_callback, spi,
584 &mcspi_dma->dma_rx_channel)) {
585 dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
586 return -EAGAIN;
587 }
588
589 if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
590 omap2_mcspi_dma_tx_callback, spi,
591 &mcspi_dma->dma_tx_channel)) {
592 omap_free_dma(mcspi_dma->dma_rx_channel);
593 mcspi_dma->dma_rx_channel = -1;
594 dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
595 return -EAGAIN;
596 }
597
598 init_completion(&mcspi_dma->dma_rx_completion);
599 init_completion(&mcspi_dma->dma_tx_completion);
600
601 return 0;
602 }
603
604 /* the spi->mode bits understood by this driver: */
605 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
606
607 static int omap2_mcspi_setup(struct spi_device *spi)
608 {
609 int ret;
610 struct omap2_mcspi *mcspi;
611 struct omap2_mcspi_dma *mcspi_dma;
612 struct omap2_mcspi_cs *cs = spi->controller_state;
613
614 if (spi->mode & ~MODEBITS) {
615 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
616 spi->mode & ~MODEBITS);
617 return -EINVAL;
618 }
619
620 if (spi->bits_per_word == 0)
621 spi->bits_per_word = 8;
622 else if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
623 dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
624 spi->bits_per_word);
625 return -EINVAL;
626 }
627
628 mcspi = spi_master_get_devdata(spi->master);
629 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
630
631 if (!cs) {
632 cs = kzalloc(sizeof *cs, GFP_KERNEL);
633 if (!cs)
634 return -ENOMEM;
635 cs->base = mcspi->base + spi->chip_select * 0x14;
636 spi->controller_state = cs;
637 }
638
639 if (mcspi_dma->dma_rx_channel == -1
640 || mcspi_dma->dma_tx_channel == -1) {
641 ret = omap2_mcspi_request_dma(spi);
642 if (ret < 0)
643 return ret;
644 }
645
646 clk_enable(mcspi->ick);
647 clk_enable(mcspi->fck);
648 ret = omap2_mcspi_setup_transfer(spi, NULL);
649 clk_disable(mcspi->fck);
650 clk_disable(mcspi->ick);
651
652 return ret;
653 }
654
655 static void omap2_mcspi_cleanup(struct spi_device *spi)
656 {
657 struct omap2_mcspi *mcspi;
658 struct omap2_mcspi_dma *mcspi_dma;
659
660 mcspi = spi_master_get_devdata(spi->master);
661 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
662
663 kfree(spi->controller_state);
664
665 if (mcspi_dma->dma_rx_channel != -1) {
666 omap_free_dma(mcspi_dma->dma_rx_channel);
667 mcspi_dma->dma_rx_channel = -1;
668 }
669 if (mcspi_dma->dma_tx_channel != -1) {
670 omap_free_dma(mcspi_dma->dma_tx_channel);
671 mcspi_dma->dma_tx_channel = -1;
672 }
673 }
674
675 static void omap2_mcspi_work(struct work_struct *work)
676 {
677 struct omap2_mcspi *mcspi;
678
679 mcspi = container_of(work, struct omap2_mcspi, work);
680 spin_lock_irq(&mcspi->lock);
681
682 clk_enable(mcspi->ick);
683 clk_enable(mcspi->fck);
684
685 /* We only enable one channel at a time -- the one whose message is
686 * at the head of the queue -- although this controller would gladly
687 * arbitrate among multiple channels. This corresponds to "single
688 * channel" master mode. As a side effect, we need to manage the
689 * chipselect with the FORCE bit ... CS != channel enable.
690 */
691 while (!list_empty(&mcspi->msg_queue)) {
692 struct spi_message *m;
693 struct spi_device *spi;
694 struct spi_transfer *t = NULL;
695 int cs_active = 0;
696 struct omap2_mcspi_cs *cs;
697 int par_override = 0;
698 int status = 0;
699 u32 chconf;
700
701 m = container_of(mcspi->msg_queue.next, struct spi_message,
702 queue);
703
704 list_del_init(&m->queue);
705 spin_unlock_irq(&mcspi->lock);
706
707 spi = m->spi;
708 cs = spi->controller_state;
709
710 omap2_mcspi_set_enable(spi, 1);
711 list_for_each_entry(t, &m->transfers, transfer_list) {
712 if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
713 status = -EINVAL;
714 break;
715 }
716 if (par_override || t->speed_hz || t->bits_per_word) {
717 par_override = 1;
718 status = omap2_mcspi_setup_transfer(spi, t);
719 if (status < 0)
720 break;
721 if (!t->speed_hz && !t->bits_per_word)
722 par_override = 0;
723 }
724
725 if (!cs_active) {
726 omap2_mcspi_force_cs(spi, 1);
727 cs_active = 1;
728 }
729
730 chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
731 chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
732 if (t->tx_buf == NULL)
733 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
734 else if (t->rx_buf == NULL)
735 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
736 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, chconf);
737
738 if (t->len) {
739 unsigned count;
740
741 /* RX_ONLY mode needs dummy data in TX reg */
742 if (t->tx_buf == NULL)
743 __raw_writel(0, cs->base
744 + OMAP2_MCSPI_TX0);
745
746 if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
747 count = omap2_mcspi_txrx_dma(spi, t);
748 else
749 count = omap2_mcspi_txrx_pio(spi, t);
750 m->actual_length += count;
751
752 if (count != t->len) {
753 status = -EIO;
754 break;
755 }
756 }
757
758 if (t->delay_usecs)
759 udelay(t->delay_usecs);
760
761 /* ignore the "leave it on after last xfer" hint */
762 if (t->cs_change) {
763 omap2_mcspi_force_cs(spi, 0);
764 cs_active = 0;
765 }
766 }
767
768 /* Restore defaults if they were overriden */
769 if (par_override) {
770 par_override = 0;
771 status = omap2_mcspi_setup_transfer(spi, NULL);
772 }
773
774 if (cs_active)
775 omap2_mcspi_force_cs(spi, 0);
776
777 omap2_mcspi_set_enable(spi, 0);
778
779 m->status = status;
780 m->complete(m->context);
781
782 spin_lock_irq(&mcspi->lock);
783 }
784
785 clk_disable(mcspi->fck);
786 clk_disable(mcspi->ick);
787
788 spin_unlock_irq(&mcspi->lock);
789 }
790
791 static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
792 {
793 struct omap2_mcspi *mcspi;
794 unsigned long flags;
795 struct spi_transfer *t;
796
797 m->actual_length = 0;
798 m->status = 0;
799
800 /* reject invalid messages and transfers */
801 if (list_empty(&m->transfers) || !m->complete)
802 return -EINVAL;
803 list_for_each_entry(t, &m->transfers, transfer_list) {
804 const void *tx_buf = t->tx_buf;
805 void *rx_buf = t->rx_buf;
806 unsigned len = t->len;
807
808 if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
809 || (len && !(rx_buf || tx_buf))
810 || (t->bits_per_word &&
811 ( t->bits_per_word < 4
812 || t->bits_per_word > 32))) {
813 dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
814 t->speed_hz,
815 len,
816 tx_buf ? "tx" : "",
817 rx_buf ? "rx" : "",
818 t->bits_per_word);
819 return -EINVAL;
820 }
821 if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
822 dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
823 t->speed_hz,
824 OMAP2_MCSPI_MAX_FREQ/(1<<16));
825 return -EINVAL;
826 }
827
828 if (m->is_dma_mapped || len < DMA_MIN_BYTES)
829 continue;
830
831 /* Do DMA mapping "early" for better error reporting and
832 * dcache use. Note that if dma_unmap_single() ever starts
833 * to do real work on ARM, we'd need to clean up mappings
834 * for previous transfers on *ALL* exits of this loop...
835 */
836 if (tx_buf != NULL) {
837 t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
838 len, DMA_TO_DEVICE);
839 if (dma_mapping_error(&spi->dev, t->tx_dma)) {
840 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
841 'T', len);
842 return -EINVAL;
843 }
844 }
845 if (rx_buf != NULL) {
846 t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
847 DMA_FROM_DEVICE);
848 if (dma_mapping_error(&spi->dev, t->rx_dma)) {
849 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
850 'R', len);
851 if (tx_buf != NULL)
852 dma_unmap_single(NULL, t->tx_dma,
853 len, DMA_TO_DEVICE);
854 return -EINVAL;
855 }
856 }
857 }
858
859 mcspi = spi_master_get_devdata(spi->master);
860
861 spin_lock_irqsave(&mcspi->lock, flags);
862 list_add_tail(&m->queue, &mcspi->msg_queue);
863 queue_work(omap2_mcspi_wq, &mcspi->work);
864 spin_unlock_irqrestore(&mcspi->lock, flags);
865
866 return 0;
867 }
868
869 static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
870 {
871 struct spi_master *master = mcspi->master;
872 u32 tmp;
873
874 clk_enable(mcspi->ick);
875 clk_enable(mcspi->fck);
876
877 mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
878 OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
879 do {
880 tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
881 } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
882
883 mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
884 /* (3 << 8) | (2 << 3) | */
885 OMAP2_MCSPI_SYSCONFIG_AUTOIDLE);
886
887 omap2_mcspi_set_master_mode(master);
888
889 clk_disable(mcspi->fck);
890 clk_disable(mcspi->ick);
891 return 0;
892 }
893
894 static u8 __initdata spi1_rxdma_id [] = {
895 OMAP24XX_DMA_SPI1_RX0,
896 OMAP24XX_DMA_SPI1_RX1,
897 OMAP24XX_DMA_SPI1_RX2,
898 OMAP24XX_DMA_SPI1_RX3,
899 };
900
901 static u8 __initdata spi1_txdma_id [] = {
902 OMAP24XX_DMA_SPI1_TX0,
903 OMAP24XX_DMA_SPI1_TX1,
904 OMAP24XX_DMA_SPI1_TX2,
905 OMAP24XX_DMA_SPI1_TX3,
906 };
907
908 static u8 __initdata spi2_rxdma_id[] = {
909 OMAP24XX_DMA_SPI2_RX0,
910 OMAP24XX_DMA_SPI2_RX1,
911 };
912
913 static u8 __initdata spi2_txdma_id[] = {
914 OMAP24XX_DMA_SPI2_TX0,
915 OMAP24XX_DMA_SPI2_TX1,
916 };
917
918 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP34XX)
919 static u8 __initdata spi3_rxdma_id[] = {
920 OMAP24XX_DMA_SPI3_RX0,
921 OMAP24XX_DMA_SPI3_RX1,
922 };
923
924 static u8 __initdata spi3_txdma_id[] = {
925 OMAP24XX_DMA_SPI3_TX0,
926 OMAP24XX_DMA_SPI3_TX1,
927 };
928 #endif
929
930 #ifdef CONFIG_ARCH_OMAP3
931 static u8 __initdata spi4_rxdma_id[] = {
932 OMAP34XX_DMA_SPI4_RX0,
933 };
934
935 static u8 __initdata spi4_txdma_id[] = {
936 OMAP34XX_DMA_SPI4_TX0,
937 };
938 #endif
939
940 static int __init omap2_mcspi_probe(struct platform_device *pdev)
941 {
942 struct spi_master *master;
943 struct omap2_mcspi *mcspi;
944 struct resource *r;
945 int status = 0, i;
946 const u8 *rxdma_id, *txdma_id;
947 unsigned num_chipselect;
948
949 switch (pdev->id) {
950 case 1:
951 rxdma_id = spi1_rxdma_id;
952 txdma_id = spi1_txdma_id;
953 num_chipselect = 4;
954 break;
955 case 2:
956 rxdma_id = spi2_rxdma_id;
957 txdma_id = spi2_txdma_id;
958 num_chipselect = 2;
959 break;
960 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3)
961 case 3:
962 rxdma_id = spi3_rxdma_id;
963 txdma_id = spi3_txdma_id;
964 num_chipselect = 2;
965 break;
966 #endif
967 #ifdef CONFIG_ARCH_OMAP3
968 case 4:
969 rxdma_id = spi4_rxdma_id;
970 txdma_id = spi4_txdma_id;
971 num_chipselect = 1;
972 break;
973 #endif
974 default:
975 return -EINVAL;
976 }
977
978 master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
979 if (master == NULL) {
980 dev_dbg(&pdev->dev, "master allocation failed\n");
981 return -ENOMEM;
982 }
983
984 if (pdev->id != -1)
985 master->bus_num = pdev->id;
986
987 master->setup = omap2_mcspi_setup;
988 master->transfer = omap2_mcspi_transfer;
989 master->cleanup = omap2_mcspi_cleanup;
990 master->num_chipselect = num_chipselect;
991
992 dev_set_drvdata(&pdev->dev, master);
993
994 mcspi = spi_master_get_devdata(master);
995 mcspi->master = master;
996
997 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
998 if (r == NULL) {
999 status = -ENODEV;
1000 goto err1;
1001 }
1002 if (!request_mem_region(r->start, (r->end - r->start) + 1,
1003 pdev->dev.bus_id)) {
1004 status = -EBUSY;
1005 goto err1;
1006 }
1007
1008 mcspi->base = (void __iomem *) io_p2v(r->start);
1009
1010 INIT_WORK(&mcspi->work, omap2_mcspi_work);
1011
1012 spin_lock_init(&mcspi->lock);
1013 INIT_LIST_HEAD(&mcspi->msg_queue);
1014
1015 mcspi->ick = clk_get(&pdev->dev, "mcspi_ick");
1016 if (IS_ERR(mcspi->ick)) {
1017 dev_dbg(&pdev->dev, "can't get mcspi_ick\n");
1018 status = PTR_ERR(mcspi->ick);
1019 goto err1a;
1020 }
1021 mcspi->fck = clk_get(&pdev->dev, "mcspi_fck");
1022 if (IS_ERR(mcspi->fck)) {
1023 dev_dbg(&pdev->dev, "can't get mcspi_fck\n");
1024 status = PTR_ERR(mcspi->fck);
1025 goto err2;
1026 }
1027
1028 mcspi->dma_channels = kcalloc(master->num_chipselect,
1029 sizeof(struct omap2_mcspi_dma),
1030 GFP_KERNEL);
1031
1032 if (mcspi->dma_channels == NULL)
1033 goto err3;
1034
1035 for (i = 0; i < num_chipselect; i++) {
1036 mcspi->dma_channels[i].dma_rx_channel = -1;
1037 mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i];
1038 mcspi->dma_channels[i].dma_tx_channel = -1;
1039 mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i];
1040 }
1041
1042 if (omap2_mcspi_reset(mcspi) < 0)
1043 goto err4;
1044
1045 status = spi_register_master(master);
1046 if (status < 0)
1047 goto err4;
1048
1049 return status;
1050
1051 err4:
1052 kfree(mcspi->dma_channels);
1053 err3:
1054 clk_put(mcspi->fck);
1055 err2:
1056 clk_put(mcspi->ick);
1057 err1a:
1058 release_mem_region(r->start, (r->end - r->start) + 1);
1059 err1:
1060 spi_master_put(master);
1061 return status;
1062 }
1063
1064 static int __exit omap2_mcspi_remove(struct platform_device *pdev)
1065 {
1066 struct spi_master *master;
1067 struct omap2_mcspi *mcspi;
1068 struct omap2_mcspi_dma *dma_channels;
1069 struct resource *r;
1070
1071 master = dev_get_drvdata(&pdev->dev);
1072 mcspi = spi_master_get_devdata(master);
1073 dma_channels = mcspi->dma_channels;
1074
1075 clk_put(mcspi->fck);
1076 clk_put(mcspi->ick);
1077
1078 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1079 release_mem_region(r->start, (r->end - r->start) + 1);
1080
1081 spi_unregister_master(master);
1082 kfree(dma_channels);
1083
1084 return 0;
1085 }
1086
1087 /* work with hotplug and coldplug */
1088 MODULE_ALIAS("platform:omap2_mcspi");
1089
1090 static struct platform_driver omap2_mcspi_driver = {
1091 .driver = {
1092 .name = "omap2_mcspi",
1093 .owner = THIS_MODULE,
1094 },
1095 .remove = __exit_p(omap2_mcspi_remove),
1096 };
1097
1098
1099 static int __init omap2_mcspi_init(void)
1100 {
1101 omap2_mcspi_wq = create_singlethread_workqueue(
1102 omap2_mcspi_driver.driver.name);
1103 if (omap2_mcspi_wq == NULL)
1104 return -1;
1105 return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
1106 }
1107 subsys_initcall(omap2_mcspi_init);
1108
1109 static void __exit omap2_mcspi_exit(void)
1110 {
1111 platform_driver_unregister(&omap2_mcspi_driver);
1112
1113 destroy_workqueue(omap2_mcspi_wq);
1114 }
1115 module_exit(omap2_mcspi_exit);
1116
1117 MODULE_LICENSE("GPL");
Support for the Chinese Samsung S3C2440 based development boards