Merge branch 'omap-boards' into omap-for-linus
[pandora-kernel.git] / drivers / spi / omap2_mcspi.c
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 #include <linux/slab.h>
36
37 #include <linux/spi/spi.h>
38
39 #include <plat/dma.h>
40 #include <plat/clock.h>
41
42
43 #define OMAP2_MCSPI_MAX_FREQ            48000000
44
45 /* OMAP2 has 3 SPI controllers, while OMAP3 has 4 */
46 #define OMAP2_MCSPI_MAX_CTRL            4
47
48 #define OMAP2_MCSPI_REVISION            0x00
49 #define OMAP2_MCSPI_SYSCONFIG           0x10
50 #define OMAP2_MCSPI_SYSSTATUS           0x14
51 #define OMAP2_MCSPI_IRQSTATUS           0x18
52 #define OMAP2_MCSPI_IRQENABLE           0x1c
53 #define OMAP2_MCSPI_WAKEUPENABLE        0x20
54 #define OMAP2_MCSPI_SYST                0x24
55 #define OMAP2_MCSPI_MODULCTRL           0x28
56
57 /* per-channel banks, 0x14 bytes each, first is: */
58 #define OMAP2_MCSPI_CHCONF0             0x2c
59 #define OMAP2_MCSPI_CHSTAT0             0x30
60 #define OMAP2_MCSPI_CHCTRL0             0x34
61 #define OMAP2_MCSPI_TX0                 0x38
62 #define OMAP2_MCSPI_RX0                 0x3c
63
64 /* per-register bitmasks: */
65
66 #define OMAP2_MCSPI_SYSCONFIG_SMARTIDLE BIT(4)
67 #define OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP BIT(2)
68 #define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE  BIT(0)
69 #define OMAP2_MCSPI_SYSCONFIG_SOFTRESET BIT(1)
70
71 #define OMAP2_MCSPI_SYSSTATUS_RESETDONE BIT(0)
72
73 #define OMAP2_MCSPI_MODULCTRL_SINGLE    BIT(0)
74 #define OMAP2_MCSPI_MODULCTRL_MS        BIT(2)
75 #define OMAP2_MCSPI_MODULCTRL_STEST     BIT(3)
76
77 #define OMAP2_MCSPI_CHCONF_PHA          BIT(0)
78 #define OMAP2_MCSPI_CHCONF_POL          BIT(1)
79 #define OMAP2_MCSPI_CHCONF_CLKD_MASK    (0x0f << 2)
80 #define OMAP2_MCSPI_CHCONF_EPOL         BIT(6)
81 #define OMAP2_MCSPI_CHCONF_WL_MASK      (0x1f << 7)
82 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY  BIT(12)
83 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY  BIT(13)
84 #define OMAP2_MCSPI_CHCONF_TRM_MASK     (0x03 << 12)
85 #define OMAP2_MCSPI_CHCONF_DMAW         BIT(14)
86 #define OMAP2_MCSPI_CHCONF_DMAR         BIT(15)
87 #define OMAP2_MCSPI_CHCONF_DPE0         BIT(16)
88 #define OMAP2_MCSPI_CHCONF_DPE1         BIT(17)
89 #define OMAP2_MCSPI_CHCONF_IS           BIT(18)
90 #define OMAP2_MCSPI_CHCONF_TURBO        BIT(19)
91 #define OMAP2_MCSPI_CHCONF_FORCE        BIT(20)
92
93 #define OMAP2_MCSPI_CHSTAT_RXS          BIT(0)
94 #define OMAP2_MCSPI_CHSTAT_TXS          BIT(1)
95 #define OMAP2_MCSPI_CHSTAT_EOT          BIT(2)
96
97 #define OMAP2_MCSPI_CHCTRL_EN           BIT(0)
98
99 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN   BIT(0)
100
101 /* We have 2 DMA channels per CS, one for RX and one for TX */
102 struct omap2_mcspi_dma {
103         int dma_tx_channel;
104         int dma_rx_channel;
105
106         int dma_tx_sync_dev;
107         int dma_rx_sync_dev;
108
109         struct completion dma_tx_completion;
110         struct completion dma_rx_completion;
111 };
112
113 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
114  * cache operations; better heuristics consider wordsize and bitrate.
115  */
116 #define DMA_MIN_BYTES                   8
117
118
119 struct omap2_mcspi {
120         struct work_struct      work;
121         /* lock protects queue and registers */
122         spinlock_t              lock;
123         struct list_head        msg_queue;
124         struct spi_master       *master;
125         struct clk              *ick;
126         struct clk              *fck;
127         /* Virtual base address of the controller */
128         void __iomem            *base;
129         unsigned long           phys;
130         /* SPI1 has 4 channels, while SPI2 has 2 */
131         struct omap2_mcspi_dma  *dma_channels;
132 };
133
134 struct omap2_mcspi_cs {
135         void __iomem            *base;
136         unsigned long           phys;
137         int                     word_len;
138         struct list_head        node;
139         /* Context save and restore shadow register */
140         u32                     chconf0;
141 };
142
143 /* used for context save and restore, structure members to be updated whenever
144  * corresponding registers are modified.
145  */
146 struct omap2_mcspi_regs {
147         u32 sysconfig;
148         u32 modulctrl;
149         u32 wakeupenable;
150         struct list_head cs;
151 };
152
153 static struct omap2_mcspi_regs omap2_mcspi_ctx[OMAP2_MCSPI_MAX_CTRL];
154
155 static struct workqueue_struct *omap2_mcspi_wq;
156
157 #define MOD_REG_BIT(val, mask, set) do { \
158         if (set) \
159                 val |= mask; \
160         else \
161                 val &= ~mask; \
162 } while (0)
163
164 static inline void mcspi_write_reg(struct spi_master *master,
165                 int idx, u32 val)
166 {
167         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
168
169         __raw_writel(val, mcspi->base + idx);
170 }
171
172 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
173 {
174         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
175
176         return __raw_readl(mcspi->base + idx);
177 }
178
179 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
180                 int idx, u32 val)
181 {
182         struct omap2_mcspi_cs   *cs = spi->controller_state;
183
184         __raw_writel(val, cs->base +  idx);
185 }
186
187 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
188 {
189         struct omap2_mcspi_cs   *cs = spi->controller_state;
190
191         return __raw_readl(cs->base + idx);
192 }
193
194 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
195 {
196         struct omap2_mcspi_cs *cs = spi->controller_state;
197
198         return cs->chconf0;
199 }
200
201 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
202 {
203         struct omap2_mcspi_cs *cs = spi->controller_state;
204
205         cs->chconf0 = val;
206         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
207         mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
208 }
209
210 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
211                 int is_read, int enable)
212 {
213         u32 l, rw;
214
215         l = mcspi_cached_chconf0(spi);
216
217         if (is_read) /* 1 is read, 0 write */
218                 rw = OMAP2_MCSPI_CHCONF_DMAR;
219         else
220                 rw = OMAP2_MCSPI_CHCONF_DMAW;
221
222         MOD_REG_BIT(l, rw, enable);
223         mcspi_write_chconf0(spi, l);
224 }
225
226 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
227 {
228         u32 l;
229
230         l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
231         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
232 }
233
234 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
235 {
236         u32 l;
237
238         l = mcspi_cached_chconf0(spi);
239         MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
240         mcspi_write_chconf0(spi, l);
241 }
242
243 static void omap2_mcspi_set_master_mode(struct spi_master *master)
244 {
245         u32 l;
246
247         /* setup when switching from (reset default) slave mode
248          * to single-channel master mode
249          */
250         l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
251         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
252         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
253         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
254         mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
255
256         omap2_mcspi_ctx[master->bus_num - 1].modulctrl = l;
257 }
258
259 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
260 {
261         struct spi_master *spi_cntrl;
262         struct omap2_mcspi_cs *cs;
263         spi_cntrl = mcspi->master;
264
265         /* McSPI: context restore */
266         mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL,
267                         omap2_mcspi_ctx[spi_cntrl->bus_num - 1].modulctrl);
268
269         mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_SYSCONFIG,
270                         omap2_mcspi_ctx[spi_cntrl->bus_num - 1].sysconfig);
271
272         mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE,
273                         omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable);
274
275         list_for_each_entry(cs, &omap2_mcspi_ctx[spi_cntrl->bus_num - 1].cs,
276                         node)
277                 __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
278 }
279 static void omap2_mcspi_disable_clocks(struct omap2_mcspi *mcspi)
280 {
281         clk_disable(mcspi->ick);
282         clk_disable(mcspi->fck);
283 }
284
285 static int omap2_mcspi_enable_clocks(struct omap2_mcspi *mcspi)
286 {
287         if (clk_enable(mcspi->ick))
288                 return -ENODEV;
289         if (clk_enable(mcspi->fck))
290                 return -ENODEV;
291
292         omap2_mcspi_restore_ctx(mcspi);
293
294         return 0;
295 }
296
297 static unsigned
298 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
299 {
300         struct omap2_mcspi      *mcspi;
301         struct omap2_mcspi_cs   *cs = spi->controller_state;
302         struct omap2_mcspi_dma  *mcspi_dma;
303         unsigned int            count, c;
304         unsigned long           base, tx_reg, rx_reg;
305         int                     word_len, data_type, element_count;
306         u8                      * rx;
307         const u8                * tx;
308
309         mcspi = spi_master_get_devdata(spi->master);
310         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
311
312         count = xfer->len;
313         c = count;
314         word_len = cs->word_len;
315
316         base = cs->phys;
317         tx_reg = base + OMAP2_MCSPI_TX0;
318         rx_reg = base + OMAP2_MCSPI_RX0;
319         rx = xfer->rx_buf;
320         tx = xfer->tx_buf;
321
322         if (word_len <= 8) {
323                 data_type = OMAP_DMA_DATA_TYPE_S8;
324                 element_count = count;
325         } else if (word_len <= 16) {
326                 data_type = OMAP_DMA_DATA_TYPE_S16;
327                 element_count = count >> 1;
328         } else /* word_len <= 32 */ {
329                 data_type = OMAP_DMA_DATA_TYPE_S32;
330                 element_count = count >> 2;
331         }
332
333         if (tx != NULL) {
334                 omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
335                                 data_type, element_count, 1,
336                                 OMAP_DMA_SYNC_ELEMENT,
337                                 mcspi_dma->dma_tx_sync_dev, 0);
338
339                 omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
340                                 OMAP_DMA_AMODE_CONSTANT,
341                                 tx_reg, 0, 0);
342
343                 omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
344                                 OMAP_DMA_AMODE_POST_INC,
345                                 xfer->tx_dma, 0, 0);
346         }
347
348         if (rx != NULL) {
349                 omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
350                                 data_type, element_count - 1, 1,
351                                 OMAP_DMA_SYNC_ELEMENT,
352                                 mcspi_dma->dma_rx_sync_dev, 1);
353
354                 omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
355                                 OMAP_DMA_AMODE_CONSTANT,
356                                 rx_reg, 0, 0);
357
358                 omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
359                                 OMAP_DMA_AMODE_POST_INC,
360                                 xfer->rx_dma, 0, 0);
361         }
362
363         if (tx != NULL) {
364                 omap_start_dma(mcspi_dma->dma_tx_channel);
365                 omap2_mcspi_set_dma_req(spi, 0, 1);
366         }
367
368         if (rx != NULL) {
369                 omap_start_dma(mcspi_dma->dma_rx_channel);
370                 omap2_mcspi_set_dma_req(spi, 1, 1);
371         }
372
373         if (tx != NULL) {
374                 wait_for_completion(&mcspi_dma->dma_tx_completion);
375                 dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE);
376         }
377
378         if (rx != NULL) {
379                 wait_for_completion(&mcspi_dma->dma_rx_completion);
380                 dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
381                 omap2_mcspi_set_enable(spi, 0);
382                 if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
383                                 & OMAP2_MCSPI_CHSTAT_RXS)) {
384                         u32 w;
385
386                         w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
387                         if (word_len <= 8)
388                                 ((u8 *)xfer->rx_buf)[element_count - 1] = w;
389                         else if (word_len <= 16)
390                                 ((u16 *)xfer->rx_buf)[element_count - 1] = w;
391                         else /* word_len <= 32 */
392                                 ((u32 *)xfer->rx_buf)[element_count - 1] = w;
393                 } else {
394                         dev_err(&spi->dev, "DMA RX last word empty");
395                         count -= (word_len <= 8)  ? 1 :
396                                  (word_len <= 16) ? 2 :
397                                /* word_len <= 32 */ 4;
398                 }
399                 omap2_mcspi_set_enable(spi, 1);
400         }
401         return count;
402 }
403
404 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
405 {
406         unsigned long timeout;
407
408         timeout = jiffies + msecs_to_jiffies(1000);
409         while (!(__raw_readl(reg) & bit)) {
410                 if (time_after(jiffies, timeout))
411                         return -1;
412                 cpu_relax();
413         }
414         return 0;
415 }
416
417 static unsigned
418 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
419 {
420         struct omap2_mcspi      *mcspi;
421         struct omap2_mcspi_cs   *cs = spi->controller_state;
422         unsigned int            count, c;
423         u32                     l;
424         void __iomem            *base = cs->base;
425         void __iomem            *tx_reg;
426         void __iomem            *rx_reg;
427         void __iomem            *chstat_reg;
428         int                     word_len;
429
430         mcspi = spi_master_get_devdata(spi->master);
431         count = xfer->len;
432         c = count;
433         word_len = cs->word_len;
434
435         l = mcspi_cached_chconf0(spi);
436         l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
437
438         /* We store the pre-calculated register addresses on stack to speed
439          * up the transfer loop. */
440         tx_reg          = base + OMAP2_MCSPI_TX0;
441         rx_reg          = base + OMAP2_MCSPI_RX0;
442         chstat_reg      = base + OMAP2_MCSPI_CHSTAT0;
443
444         if (word_len <= 8) {
445                 u8              *rx;
446                 const u8        *tx;
447
448                 rx = xfer->rx_buf;
449                 tx = xfer->tx_buf;
450
451                 do {
452                         c -= 1;
453                         if (tx != NULL) {
454                                 if (mcspi_wait_for_reg_bit(chstat_reg,
455                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
456                                         dev_err(&spi->dev, "TXS timed out\n");
457                                         goto out;
458                                 }
459 #ifdef VERBOSE
460                                 dev_dbg(&spi->dev, "write-%d %02x\n",
461                                                 word_len, *tx);
462 #endif
463                                 __raw_writel(*tx++, tx_reg);
464                         }
465                         if (rx != NULL) {
466                                 if (mcspi_wait_for_reg_bit(chstat_reg,
467                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
468                                         dev_err(&spi->dev, "RXS timed out\n");
469                                         goto out;
470                                 }
471                                 /* prevent last RX_ONLY read from triggering
472                                  * more word i/o: switch to rx+tx
473                                  */
474                                 if (c == 0 && tx == NULL)
475                                         mcspi_write_chconf0(spi, l);
476                                 *rx++ = __raw_readl(rx_reg);
477 #ifdef VERBOSE
478                                 dev_dbg(&spi->dev, "read-%d %02x\n",
479                                                 word_len, *(rx - 1));
480 #endif
481                         }
482                 } while (c);
483         } else if (word_len <= 16) {
484                 u16             *rx;
485                 const u16       *tx;
486
487                 rx = xfer->rx_buf;
488                 tx = xfer->tx_buf;
489                 do {
490                         c -= 2;
491                         if (tx != NULL) {
492                                 if (mcspi_wait_for_reg_bit(chstat_reg,
493                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
494                                         dev_err(&spi->dev, "TXS timed out\n");
495                                         goto out;
496                                 }
497 #ifdef VERBOSE
498                                 dev_dbg(&spi->dev, "write-%d %04x\n",
499                                                 word_len, *tx);
500 #endif
501                                 __raw_writel(*tx++, tx_reg);
502                         }
503                         if (rx != NULL) {
504                                 if (mcspi_wait_for_reg_bit(chstat_reg,
505                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
506                                         dev_err(&spi->dev, "RXS timed out\n");
507                                         goto out;
508                                 }
509                                 /* prevent last RX_ONLY read from triggering
510                                  * more word i/o: switch to rx+tx
511                                  */
512                                 if (c == 0 && tx == NULL)
513                                         mcspi_write_chconf0(spi, l);
514                                 *rx++ = __raw_readl(rx_reg);
515 #ifdef VERBOSE
516                                 dev_dbg(&spi->dev, "read-%d %04x\n",
517                                                 word_len, *(rx - 1));
518 #endif
519                         }
520                 } while (c);
521         } else if (word_len <= 32) {
522                 u32             *rx;
523                 const u32       *tx;
524
525                 rx = xfer->rx_buf;
526                 tx = xfer->tx_buf;
527                 do {
528                         c -= 4;
529                         if (tx != NULL) {
530                                 if (mcspi_wait_for_reg_bit(chstat_reg,
531                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
532                                         dev_err(&spi->dev, "TXS timed out\n");
533                                         goto out;
534                                 }
535 #ifdef VERBOSE
536                                 dev_dbg(&spi->dev, "write-%d %08x\n",
537                                                 word_len, *tx);
538 #endif
539                                 __raw_writel(*tx++, tx_reg);
540                         }
541                         if (rx != NULL) {
542                                 if (mcspi_wait_for_reg_bit(chstat_reg,
543                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
544                                         dev_err(&spi->dev, "RXS timed out\n");
545                                         goto out;
546                                 }
547                                 /* prevent last RX_ONLY read from triggering
548                                  * more word i/o: switch to rx+tx
549                                  */
550                                 if (c == 0 && tx == NULL)
551                                         mcspi_write_chconf0(spi, l);
552                                 *rx++ = __raw_readl(rx_reg);
553 #ifdef VERBOSE
554                                 dev_dbg(&spi->dev, "read-%d %08x\n",
555                                                 word_len, *(rx - 1));
556 #endif
557                         }
558                 } while (c);
559         }
560
561         /* for TX_ONLY mode, be sure all words have shifted out */
562         if (xfer->rx_buf == NULL) {
563                 if (mcspi_wait_for_reg_bit(chstat_reg,
564                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
565                         dev_err(&spi->dev, "TXS timed out\n");
566                 } else if (mcspi_wait_for_reg_bit(chstat_reg,
567                                 OMAP2_MCSPI_CHSTAT_EOT) < 0)
568                         dev_err(&spi->dev, "EOT timed out\n");
569         }
570 out:
571         return count - c;
572 }
573
574 /* called only when no transfer is active to this device */
575 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
576                 struct spi_transfer *t)
577 {
578         struct omap2_mcspi_cs *cs = spi->controller_state;
579         struct omap2_mcspi *mcspi;
580         struct spi_master *spi_cntrl;
581         u32 l = 0, div = 0;
582         u8 word_len = spi->bits_per_word;
583         u32 speed_hz = spi->max_speed_hz;
584
585         mcspi = spi_master_get_devdata(spi->master);
586         spi_cntrl = mcspi->master;
587
588         if (t != NULL && t->bits_per_word)
589                 word_len = t->bits_per_word;
590
591         cs->word_len = word_len;
592
593         if (t && t->speed_hz)
594                 speed_hz = t->speed_hz;
595
596         if (speed_hz) {
597                 while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
598                                         > speed_hz)
599                         div++;
600         } else
601                 div = 15;
602
603         l = mcspi_cached_chconf0(spi);
604
605         /* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
606          * REVISIT: this controller could support SPI_3WIRE mode.
607          */
608         l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
609         l |= OMAP2_MCSPI_CHCONF_DPE0;
610
611         /* wordlength */
612         l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
613         l |= (word_len - 1) << 7;
614
615         /* set chipselect polarity; manage with FORCE */
616         if (!(spi->mode & SPI_CS_HIGH))
617                 l |= OMAP2_MCSPI_CHCONF_EPOL;   /* active-low; normal */
618         else
619                 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
620
621         /* set clock divisor */
622         l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
623         l |= div << 2;
624
625         /* set SPI mode 0..3 */
626         if (spi->mode & SPI_CPOL)
627                 l |= OMAP2_MCSPI_CHCONF_POL;
628         else
629                 l &= ~OMAP2_MCSPI_CHCONF_POL;
630         if (spi->mode & SPI_CPHA)
631                 l |= OMAP2_MCSPI_CHCONF_PHA;
632         else
633                 l &= ~OMAP2_MCSPI_CHCONF_PHA;
634
635         mcspi_write_chconf0(spi, l);
636
637         dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
638                         OMAP2_MCSPI_MAX_FREQ / (1 << div),
639                         (spi->mode & SPI_CPHA) ? "trailing" : "leading",
640                         (spi->mode & SPI_CPOL) ? "inverted" : "normal");
641
642         return 0;
643 }
644
645 static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
646 {
647         struct spi_device       *spi = data;
648         struct omap2_mcspi      *mcspi;
649         struct omap2_mcspi_dma  *mcspi_dma;
650
651         mcspi = spi_master_get_devdata(spi->master);
652         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
653
654         complete(&mcspi_dma->dma_rx_completion);
655
656         /* We must disable the DMA RX request */
657         omap2_mcspi_set_dma_req(spi, 1, 0);
658 }
659
660 static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
661 {
662         struct spi_device       *spi = data;
663         struct omap2_mcspi      *mcspi;
664         struct omap2_mcspi_dma  *mcspi_dma;
665
666         mcspi = spi_master_get_devdata(spi->master);
667         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
668
669         complete(&mcspi_dma->dma_tx_completion);
670
671         /* We must disable the DMA TX request */
672         omap2_mcspi_set_dma_req(spi, 0, 0);
673 }
674
675 static int omap2_mcspi_request_dma(struct spi_device *spi)
676 {
677         struct spi_master       *master = spi->master;
678         struct omap2_mcspi      *mcspi;
679         struct omap2_mcspi_dma  *mcspi_dma;
680
681         mcspi = spi_master_get_devdata(master);
682         mcspi_dma = mcspi->dma_channels + spi->chip_select;
683
684         if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
685                         omap2_mcspi_dma_rx_callback, spi,
686                         &mcspi_dma->dma_rx_channel)) {
687                 dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
688                 return -EAGAIN;
689         }
690
691         if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
692                         omap2_mcspi_dma_tx_callback, spi,
693                         &mcspi_dma->dma_tx_channel)) {
694                 omap_free_dma(mcspi_dma->dma_rx_channel);
695                 mcspi_dma->dma_rx_channel = -1;
696                 dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
697                 return -EAGAIN;
698         }
699
700         init_completion(&mcspi_dma->dma_rx_completion);
701         init_completion(&mcspi_dma->dma_tx_completion);
702
703         return 0;
704 }
705
706 static int omap2_mcspi_setup(struct spi_device *spi)
707 {
708         int                     ret;
709         struct omap2_mcspi      *mcspi;
710         struct omap2_mcspi_dma  *mcspi_dma;
711         struct omap2_mcspi_cs   *cs = spi->controller_state;
712
713         if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
714                 dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
715                         spi->bits_per_word);
716                 return -EINVAL;
717         }
718
719         mcspi = spi_master_get_devdata(spi->master);
720         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
721
722         if (!cs) {
723                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
724                 if (!cs)
725                         return -ENOMEM;
726                 cs->base = mcspi->base + spi->chip_select * 0x14;
727                 cs->phys = mcspi->phys + spi->chip_select * 0x14;
728                 cs->chconf0 = 0;
729                 spi->controller_state = cs;
730                 /* Link this to context save list */
731                 list_add_tail(&cs->node,
732                         &omap2_mcspi_ctx[mcspi->master->bus_num - 1].cs);
733         }
734
735         if (mcspi_dma->dma_rx_channel == -1
736                         || mcspi_dma->dma_tx_channel == -1) {
737                 ret = omap2_mcspi_request_dma(spi);
738                 if (ret < 0)
739                         return ret;
740         }
741
742         if (omap2_mcspi_enable_clocks(mcspi))
743                 return -ENODEV;
744
745         ret = omap2_mcspi_setup_transfer(spi, NULL);
746         omap2_mcspi_disable_clocks(mcspi);
747
748         return ret;
749 }
750
751 static void omap2_mcspi_cleanup(struct spi_device *spi)
752 {
753         struct omap2_mcspi      *mcspi;
754         struct omap2_mcspi_dma  *mcspi_dma;
755         struct omap2_mcspi_cs   *cs;
756
757         mcspi = spi_master_get_devdata(spi->master);
758         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
759
760         if (spi->controller_state) {
761                 /* Unlink controller state from context save list */
762                 cs = spi->controller_state;
763                 list_del(&cs->node);
764
765                 kfree(spi->controller_state);
766         }
767
768         if (mcspi_dma->dma_rx_channel != -1) {
769                 omap_free_dma(mcspi_dma->dma_rx_channel);
770                 mcspi_dma->dma_rx_channel = -1;
771         }
772         if (mcspi_dma->dma_tx_channel != -1) {
773                 omap_free_dma(mcspi_dma->dma_tx_channel);
774                 mcspi_dma->dma_tx_channel = -1;
775         }
776 }
777
778 static void omap2_mcspi_work(struct work_struct *work)
779 {
780         struct omap2_mcspi      *mcspi;
781
782         mcspi = container_of(work, struct omap2_mcspi, work);
783         spin_lock_irq(&mcspi->lock);
784
785         if (omap2_mcspi_enable_clocks(mcspi))
786                 goto out;
787
788         /* We only enable one channel at a time -- the one whose message is
789          * at the head of the queue -- although this controller would gladly
790          * arbitrate among multiple channels.  This corresponds to "single
791          * channel" master mode.  As a side effect, we need to manage the
792          * chipselect with the FORCE bit ... CS != channel enable.
793          */
794         while (!list_empty(&mcspi->msg_queue)) {
795                 struct spi_message              *m;
796                 struct spi_device               *spi;
797                 struct spi_transfer             *t = NULL;
798                 int                             cs_active = 0;
799                 struct omap2_mcspi_cs           *cs;
800                 int                             par_override = 0;
801                 int                             status = 0;
802                 u32                             chconf;
803
804                 m = container_of(mcspi->msg_queue.next, struct spi_message,
805                                  queue);
806
807                 list_del_init(&m->queue);
808                 spin_unlock_irq(&mcspi->lock);
809
810                 spi = m->spi;
811                 cs = spi->controller_state;
812
813                 omap2_mcspi_set_enable(spi, 1);
814                 list_for_each_entry(t, &m->transfers, transfer_list) {
815                         if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
816                                 status = -EINVAL;
817                                 break;
818                         }
819                         if (par_override || t->speed_hz || t->bits_per_word) {
820                                 par_override = 1;
821                                 status = omap2_mcspi_setup_transfer(spi, t);
822                                 if (status < 0)
823                                         break;
824                                 if (!t->speed_hz && !t->bits_per_word)
825                                         par_override = 0;
826                         }
827
828                         if (!cs_active) {
829                                 omap2_mcspi_force_cs(spi, 1);
830                                 cs_active = 1;
831                         }
832
833                         chconf = mcspi_cached_chconf0(spi);
834                         chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
835                         if (t->tx_buf == NULL)
836                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
837                         else if (t->rx_buf == NULL)
838                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
839                         mcspi_write_chconf0(spi, chconf);
840
841                         if (t->len) {
842                                 unsigned        count;
843
844                                 /* RX_ONLY mode needs dummy data in TX reg */
845                                 if (t->tx_buf == NULL)
846                                         __raw_writel(0, cs->base
847                                                         + OMAP2_MCSPI_TX0);
848
849                                 if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
850                                         count = omap2_mcspi_txrx_dma(spi, t);
851                                 else
852                                         count = omap2_mcspi_txrx_pio(spi, t);
853                                 m->actual_length += count;
854
855                                 if (count != t->len) {
856                                         status = -EIO;
857                                         break;
858                                 }
859                         }
860
861                         if (t->delay_usecs)
862                                 udelay(t->delay_usecs);
863
864                         /* ignore the "leave it on after last xfer" hint */
865                         if (t->cs_change) {
866                                 omap2_mcspi_force_cs(spi, 0);
867                                 cs_active = 0;
868                         }
869                 }
870
871                 /* Restore defaults if they were overriden */
872                 if (par_override) {
873                         par_override = 0;
874                         status = omap2_mcspi_setup_transfer(spi, NULL);
875                 }
876
877                 if (cs_active)
878                         omap2_mcspi_force_cs(spi, 0);
879
880                 omap2_mcspi_set_enable(spi, 0);
881
882                 m->status = status;
883                 m->complete(m->context);
884
885                 spin_lock_irq(&mcspi->lock);
886         }
887
888         omap2_mcspi_disable_clocks(mcspi);
889
890 out:
891         spin_unlock_irq(&mcspi->lock);
892 }
893
894 static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
895 {
896         struct omap2_mcspi      *mcspi;
897         unsigned long           flags;
898         struct spi_transfer     *t;
899
900         m->actual_length = 0;
901         m->status = 0;
902
903         /* reject invalid messages and transfers */
904         if (list_empty(&m->transfers) || !m->complete)
905                 return -EINVAL;
906         list_for_each_entry(t, &m->transfers, transfer_list) {
907                 const void      *tx_buf = t->tx_buf;
908                 void            *rx_buf = t->rx_buf;
909                 unsigned        len = t->len;
910
911                 if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
912                                 || (len && !(rx_buf || tx_buf))
913                                 || (t->bits_per_word &&
914                                         (  t->bits_per_word < 4
915                                         || t->bits_per_word > 32))) {
916                         dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
917                                         t->speed_hz,
918                                         len,
919                                         tx_buf ? "tx" : "",
920                                         rx_buf ? "rx" : "",
921                                         t->bits_per_word);
922                         return -EINVAL;
923                 }
924                 if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
925                         dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
926                                         t->speed_hz,
927                                         OMAP2_MCSPI_MAX_FREQ/(1<<16));
928                         return -EINVAL;
929                 }
930
931                 if (m->is_dma_mapped || len < DMA_MIN_BYTES)
932                         continue;
933
934                 /* Do DMA mapping "early" for better error reporting and
935                  * dcache use.  Note that if dma_unmap_single() ever starts
936                  * to do real work on ARM, we'd need to clean up mappings
937                  * for previous transfers on *ALL* exits of this loop...
938                  */
939                 if (tx_buf != NULL) {
940                         t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
941                                         len, DMA_TO_DEVICE);
942                         if (dma_mapping_error(&spi->dev, t->tx_dma)) {
943                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
944                                                 'T', len);
945                                 return -EINVAL;
946                         }
947                 }
948                 if (rx_buf != NULL) {
949                         t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
950                                         DMA_FROM_DEVICE);
951                         if (dma_mapping_error(&spi->dev, t->rx_dma)) {
952                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
953                                                 'R', len);
954                                 if (tx_buf != NULL)
955                                         dma_unmap_single(NULL, t->tx_dma,
956                                                         len, DMA_TO_DEVICE);
957                                 return -EINVAL;
958                         }
959                 }
960         }
961
962         mcspi = spi_master_get_devdata(spi->master);
963
964         spin_lock_irqsave(&mcspi->lock, flags);
965         list_add_tail(&m->queue, &mcspi->msg_queue);
966         queue_work(omap2_mcspi_wq, &mcspi->work);
967         spin_unlock_irqrestore(&mcspi->lock, flags);
968
969         return 0;
970 }
971
972 static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
973 {
974         struct spi_master       *master = mcspi->master;
975         u32                     tmp;
976
977         if (omap2_mcspi_enable_clocks(mcspi))
978                 return -1;
979
980         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
981                         OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
982         do {
983                 tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
984         } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
985
986         tmp = OMAP2_MCSPI_SYSCONFIG_AUTOIDLE |
987                 OMAP2_MCSPI_SYSCONFIG_ENAWAKEUP |
988                 OMAP2_MCSPI_SYSCONFIG_SMARTIDLE;
989         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, tmp);
990         omap2_mcspi_ctx[master->bus_num - 1].sysconfig = tmp;
991
992         tmp = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
993         mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, tmp);
994         omap2_mcspi_ctx[master->bus_num - 1].wakeupenable = tmp;
995
996         omap2_mcspi_set_master_mode(master);
997         omap2_mcspi_disable_clocks(mcspi);
998         return 0;
999 }
1000
1001 static u8 __initdata spi1_rxdma_id [] = {
1002         OMAP24XX_DMA_SPI1_RX0,
1003         OMAP24XX_DMA_SPI1_RX1,
1004         OMAP24XX_DMA_SPI1_RX2,
1005         OMAP24XX_DMA_SPI1_RX3,
1006 };
1007
1008 static u8 __initdata spi1_txdma_id [] = {
1009         OMAP24XX_DMA_SPI1_TX0,
1010         OMAP24XX_DMA_SPI1_TX1,
1011         OMAP24XX_DMA_SPI1_TX2,
1012         OMAP24XX_DMA_SPI1_TX3,
1013 };
1014
1015 static u8 __initdata spi2_rxdma_id[] = {
1016         OMAP24XX_DMA_SPI2_RX0,
1017         OMAP24XX_DMA_SPI2_RX1,
1018 };
1019
1020 static u8 __initdata spi2_txdma_id[] = {
1021         OMAP24XX_DMA_SPI2_TX0,
1022         OMAP24XX_DMA_SPI2_TX1,
1023 };
1024
1025 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3) \
1026         || defined(CONFIG_ARCH_OMAP4)
1027 static u8 __initdata spi3_rxdma_id[] = {
1028         OMAP24XX_DMA_SPI3_RX0,
1029         OMAP24XX_DMA_SPI3_RX1,
1030 };
1031
1032 static u8 __initdata spi3_txdma_id[] = {
1033         OMAP24XX_DMA_SPI3_TX0,
1034         OMAP24XX_DMA_SPI3_TX1,
1035 };
1036 #endif
1037
1038 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
1039 static u8 __initdata spi4_rxdma_id[] = {
1040         OMAP34XX_DMA_SPI4_RX0,
1041 };
1042
1043 static u8 __initdata spi4_txdma_id[] = {
1044         OMAP34XX_DMA_SPI4_TX0,
1045 };
1046 #endif
1047
1048 static int __init omap2_mcspi_probe(struct platform_device *pdev)
1049 {
1050         struct spi_master       *master;
1051         struct omap2_mcspi      *mcspi;
1052         struct resource         *r;
1053         int                     status = 0, i;
1054         const u8                *rxdma_id, *txdma_id;
1055         unsigned                num_chipselect;
1056
1057         switch (pdev->id) {
1058         case 1:
1059                 rxdma_id = spi1_rxdma_id;
1060                 txdma_id = spi1_txdma_id;
1061                 num_chipselect = 4;
1062                 break;
1063         case 2:
1064                 rxdma_id = spi2_rxdma_id;
1065                 txdma_id = spi2_txdma_id;
1066                 num_chipselect = 2;
1067                 break;
1068 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3) \
1069         || defined(CONFIG_ARCH_OMAP4)
1070         case 3:
1071                 rxdma_id = spi3_rxdma_id;
1072                 txdma_id = spi3_txdma_id;
1073                 num_chipselect = 2;
1074                 break;
1075 #endif
1076 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
1077         case 4:
1078                 rxdma_id = spi4_rxdma_id;
1079                 txdma_id = spi4_txdma_id;
1080                 num_chipselect = 1;
1081                 break;
1082 #endif
1083         default:
1084                 return -EINVAL;
1085         }
1086
1087         master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1088         if (master == NULL) {
1089                 dev_dbg(&pdev->dev, "master allocation failed\n");
1090                 return -ENOMEM;
1091         }
1092
1093         /* the spi->mode bits understood by this driver: */
1094         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1095
1096         if (pdev->id != -1)
1097                 master->bus_num = pdev->id;
1098
1099         master->setup = omap2_mcspi_setup;
1100         master->transfer = omap2_mcspi_transfer;
1101         master->cleanup = omap2_mcspi_cleanup;
1102         master->num_chipselect = num_chipselect;
1103
1104         dev_set_drvdata(&pdev->dev, master);
1105
1106         mcspi = spi_master_get_devdata(master);
1107         mcspi->master = master;
1108
1109         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1110         if (r == NULL) {
1111                 status = -ENODEV;
1112                 goto err1;
1113         }
1114         if (!request_mem_region(r->start, (r->end - r->start) + 1,
1115                         dev_name(&pdev->dev))) {
1116                 status = -EBUSY;
1117                 goto err1;
1118         }
1119
1120         mcspi->phys = r->start;
1121         mcspi->base = ioremap(r->start, r->end - r->start + 1);
1122         if (!mcspi->base) {
1123                 dev_dbg(&pdev->dev, "can't ioremap MCSPI\n");
1124                 status = -ENOMEM;
1125                 goto err1aa;
1126         }
1127
1128         INIT_WORK(&mcspi->work, omap2_mcspi_work);
1129
1130         spin_lock_init(&mcspi->lock);
1131         INIT_LIST_HEAD(&mcspi->msg_queue);
1132         INIT_LIST_HEAD(&omap2_mcspi_ctx[master->bus_num - 1].cs);
1133
1134         mcspi->ick = clk_get(&pdev->dev, "ick");
1135         if (IS_ERR(mcspi->ick)) {
1136                 dev_dbg(&pdev->dev, "can't get mcspi_ick\n");
1137                 status = PTR_ERR(mcspi->ick);
1138                 goto err1a;
1139         }
1140         mcspi->fck = clk_get(&pdev->dev, "fck");
1141         if (IS_ERR(mcspi->fck)) {
1142                 dev_dbg(&pdev->dev, "can't get mcspi_fck\n");
1143                 status = PTR_ERR(mcspi->fck);
1144                 goto err2;
1145         }
1146
1147         mcspi->dma_channels = kcalloc(master->num_chipselect,
1148                         sizeof(struct omap2_mcspi_dma),
1149                         GFP_KERNEL);
1150
1151         if (mcspi->dma_channels == NULL)
1152                 goto err3;
1153
1154         for (i = 0; i < num_chipselect; i++) {
1155                 mcspi->dma_channels[i].dma_rx_channel = -1;
1156                 mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i];
1157                 mcspi->dma_channels[i].dma_tx_channel = -1;
1158                 mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i];
1159         }
1160
1161         if (omap2_mcspi_reset(mcspi) < 0)
1162                 goto err4;
1163
1164         status = spi_register_master(master);
1165         if (status < 0)
1166                 goto err4;
1167
1168         return status;
1169
1170 err4:
1171         kfree(mcspi->dma_channels);
1172 err3:
1173         clk_put(mcspi->fck);
1174 err2:
1175         clk_put(mcspi->ick);
1176 err1a:
1177         iounmap(mcspi->base);
1178 err1aa:
1179         release_mem_region(r->start, (r->end - r->start) + 1);
1180 err1:
1181         spi_master_put(master);
1182         return status;
1183 }
1184
1185 static int __exit omap2_mcspi_remove(struct platform_device *pdev)
1186 {
1187         struct spi_master       *master;
1188         struct omap2_mcspi      *mcspi;
1189         struct omap2_mcspi_dma  *dma_channels;
1190         struct resource         *r;
1191         void __iomem *base;
1192
1193         master = dev_get_drvdata(&pdev->dev);
1194         mcspi = spi_master_get_devdata(master);
1195         dma_channels = mcspi->dma_channels;
1196
1197         clk_put(mcspi->fck);
1198         clk_put(mcspi->ick);
1199
1200         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1201         release_mem_region(r->start, (r->end - r->start) + 1);
1202
1203         base = mcspi->base;
1204         spi_unregister_master(master);
1205         iounmap(base);
1206         kfree(dma_channels);
1207
1208         return 0;
1209 }
1210
1211 /* work with hotplug and coldplug */
1212 MODULE_ALIAS("platform:omap2_mcspi");
1213
1214 static struct platform_driver omap2_mcspi_driver = {
1215         .driver = {
1216                 .name =         "omap2_mcspi",
1217                 .owner =        THIS_MODULE,
1218         },
1219         .remove =       __exit_p(omap2_mcspi_remove),
1220 };
1221
1222
1223 static int __init omap2_mcspi_init(void)
1224 {
1225         omap2_mcspi_wq = create_singlethread_workqueue(
1226                                 omap2_mcspi_driver.driver.name);
1227         if (omap2_mcspi_wq == NULL)
1228                 return -1;
1229         return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
1230 }
1231 subsys_initcall(omap2_mcspi_init);
1232
1233 static void __exit omap2_mcspi_exit(void)
1234 {
1235         platform_driver_unregister(&omap2_mcspi_driver);
1236
1237         destroy_workqueue(omap2_mcspi_wq);
1238 }
1239 module_exit(omap2_mcspi_exit);
1240
1241 MODULE_LICENSE("GPL");