projects / deliverable / linux.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
spi: davinci: always start transmit DMA
[deliverable/linux.git] / drivers / spi / davinci_spi.c
CommitLineData
358934a6
SP		 1/*
2 * Copyright (C) 2009 Texas Instruments.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19#include <linux/interrupt.h>
20#include <linux/io.h>
21#include <linux/gpio.h>
22#include <linux/module.h>
23#include <linux/delay.h>
24#include <linux/platform_device.h>
25#include <linux/err.h>
26#include <linux/clk.h>
27#include <linux/dma-mapping.h>
28#include <linux/spi/spi.h>
29#include <linux/spi/spi_bitbang.h>
5a0e3ad6 30#include <linux/slab.h>
358934a6
SP		 31
32#include <mach/spi.h>
33#include <mach/edma.h>
34
35#define SPI_NO_RESOURCE ((resource_size_t)-1)
36
37#define SPI_MAX_CHIPSELECT 2
38
39#define CS_DEFAULT 0xFF
40
41#define SPI_BUFSIZ (SMP_CACHE_BYTES + 1)
358934a6
SP		 42
43#define SPIFMT_PHASE_MASK BIT(16)
44#define SPIFMT_POLARITY_MASK BIT(17)
45#define SPIFMT_DISTIMER_MASK BIT(18)
46#define SPIFMT_SHIFTDIR_MASK BIT(20)
47#define SPIFMT_WAITENA_MASK BIT(21)
48#define SPIFMT_PARITYENA_MASK BIT(22)
49#define SPIFMT_ODD_PARITY_MASK BIT(23)
50#define SPIFMT_WDELAY_MASK 0x3f000000u
51#define SPIFMT_WDELAY_SHIFT 24
7fe0092b 52#define SPIFMT_PRESCALE_SHIFT 8
358934a6 53
358934a6
SP		 54
55/* SPIPC0 */
56#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
57#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
58#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
59#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
358934a6
SP		 60
61#define SPIINT_MASKALL 0x0101035F
e0d205e9
BN		 62#define SPIINT_MASKINT 0x0000015F
63#define SPI_INTLVL_1 0x000001FF
64#define SPI_INTLVL_0 0x00000000
358934a6 65
cfbc5d1d
BN		 66/* SPIDAT1 (upper 16 bit defines) */
67#define SPIDAT1_CSHOLD_MASK BIT(12)
68
69/* SPIGCR1 */
358934a6
SP		 70#define SPIGCR1_CLKMOD_MASK BIT(1)
71#define SPIGCR1_MASTER_MASK BIT(0)
72#define SPIGCR1_LOOPBACK_MASK BIT(16)
8e206f1c 73#define SPIGCR1_SPIENA_MASK BIT(24)
358934a6
SP		 74
75/* SPIBUF */
76#define SPIBUF_TXFULL_MASK BIT(29)
77#define SPIBUF_RXEMPTY_MASK BIT(31)
78
7abbf23c
BN		 79/* SPIDELAY */
80#define SPIDELAY_C2TDELAY_SHIFT 24
81#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
82#define SPIDELAY_T2CDELAY_SHIFT 16
83#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
84#define SPIDELAY_T2EDELAY_SHIFT 8
85#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
86#define SPIDELAY_C2EDELAY_SHIFT 0
87#define SPIDELAY_C2EDELAY_MASK 0xFF
88
358934a6
SP		 89/* Error Masks */
90#define SPIFLG_DLEN_ERR_MASK BIT(0)
91#define SPIFLG_TIMEOUT_MASK BIT(1)
92#define SPIFLG_PARERR_MASK BIT(2)
93#define SPIFLG_DESYNC_MASK BIT(3)
94#define SPIFLG_BITERR_MASK BIT(4)
95#define SPIFLG_OVRRUN_MASK BIT(6)
358934a6 96#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
839c996c
BN		 97#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \
98 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
99 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
100 | SPIFLG_OVRRUN_MASK)
8e206f1c 101
358934a6 102#define SPIINT_DMA_REQ_EN BIT(16)
358934a6 103
358934a6
SP		 104/* SPI Controller registers */
105#define SPIGCR0 0x00
106#define SPIGCR1 0x04
107#define SPIINT 0x08
108#define SPILVL 0x0c
109#define SPIFLG 0x10
110#define SPIPC0 0x14
358934a6
SP		 111#define SPIDAT1 0x3c
112#define SPIBUF 0x40
358934a6
SP		 113#define SPIDELAY 0x48
114#define SPIDEF 0x4c
115#define SPIFMT0 0x50
358934a6 116
358934a6
SP		 117/* We have 2 DMA channels per CS, one for RX and one for TX */
118struct davinci_spi_dma {
119 int dma_tx_channel;
120 int dma_rx_channel;
121 int dma_tx_sync_dev;
122 int dma_rx_sync_dev;
123 enum dma_event_q eventq;
124
125 struct completion dma_tx_completion;
126 struct completion dma_rx_completion;
127};
128
129/* SPI Controller driver's private data. */
130struct davinci_spi {
131 struct spi_bitbang bitbang;
132 struct clk *clk;
133
134 u8 version;
135 resource_size_t pbase;
136 void __iomem *base;
137 size_t region_size;
e0d205e9
BN		 138 u32 irq;
139 struct completion done;
358934a6
SP		 140
141 const void *tx;
142 void *rx;
143 u8 *tmp_buf;
e0d205e9
BN		 144 int rcount;
145 int wcount;
96fd881f 146 struct davinci_spi_dma dma_channels;
778e261e 147 struct davinci_spi_platform_data *pdata;
358934a6
SP		 148
149 void (*get_rx)(u32 rx_data, struct davinci_spi *);
150 u32 (*get_tx)(struct davinci_spi *);
151
cda987eb 152 u8 bytes_per_word[SPI_MAX_CHIPSELECT];
358934a6
SP		 153};
154
53a31b07
BN		 155static struct davinci_spi_config davinci_spi_default_cfg;
156
358934a6
SP		 157static unsigned use_dma;
158
159static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi)
160{
53d454a1
BN		 161 if (davinci_spi->rx) {
162 u8 *rx = davinci_spi->rx;
163 *rx++ = (u8)data;
164 davinci_spi->rx = rx;
165 }
358934a6
SP		 166}
167
168static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *davinci_spi)
169{
53d454a1
BN		 170 if (davinci_spi->rx) {
171 u16 *rx = davinci_spi->rx;
172 *rx++ = (u16)data;
173 davinci_spi->rx = rx;
174 }
358934a6
SP		 175}
176
177static u32 davinci_spi_tx_buf_u8(struct davinci_spi *davinci_spi)
178{
53d454a1
BN		 179 u32 data = 0;
180 if (davinci_spi->tx) {
181 const u8 *tx = davinci_spi->tx;
182 data = *tx++;
183 davinci_spi->tx = tx;
184 }
358934a6
SP		 185 return data;
186}
187
188static u32 davinci_spi_tx_buf_u16(struct davinci_spi *davinci_spi)
189{
53d454a1
BN		 190 u32 data = 0;
191 if (davinci_spi->tx) {
192 const u16 *tx = davinci_spi->tx;
193 data = *tx++;
194 davinci_spi->tx = tx;
195 }
358934a6
SP		 196 return data;
197}
198
199static inline void set_io_bits(void __iomem *addr, u32 bits)
200{
201 u32 v = ioread32(addr);
202
203 v |= bits;
204 iowrite32(v, addr);
205}
206
207static inline void clear_io_bits(void __iomem *addr, u32 bits)
208{
209 u32 v = ioread32(addr);
210
211 v &= ~bits;
212 iowrite32(v, addr);
213}
214
358934a6
SP		 215static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable)
216{
217 struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
218
219 if (enable)
220 set_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
221 else
222 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
223}
224
225/*
226 * Interface to control the chip select signal
227 */
228static void davinci_spi_chipselect(struct spi_device *spi, int value)
229{
230 struct davinci_spi *davinci_spi;
231 struct davinci_spi_platform_data *pdata;
7978b8c3 232 u8 chip_sel = spi->chip_select;
cfbc5d1d 233 u16 spidat1_cfg = CS_DEFAULT;
23853973 234 bool gpio_chipsel = false;
358934a6
SP		 235
236 davinci_spi = spi_master_get_devdata(spi->master);
237 pdata = davinci_spi->pdata;
238
23853973
BN		 239 if (pdata->chip_sel && chip_sel < pdata->num_chipselect &&
240 pdata->chip_sel[chip_sel] != SPI_INTERN_CS)
241 gpio_chipsel = true;
242
358934a6
SP		 243 /*
244 * Board specific chip select logic decides the polarity and cs
245 * line for the controller
246 */
23853973
BN		 247 if (gpio_chipsel) {
248 if (value == BITBANG_CS_ACTIVE)
249 gpio_set_value(pdata->chip_sel[chip_sel], 0);
250 else
251 gpio_set_value(pdata->chip_sel[chip_sel], 1);
252 } else {
253 if (value == BITBANG_CS_ACTIVE) {
254 spidat1_cfg |= SPIDAT1_CSHOLD_MASK;
255 spidat1_cfg &= ~(0x1 << chip_sel);
256 }
7978b8c3 257
23853973
BN		 258 iowrite16(spidat1_cfg, davinci_spi->base + SPIDAT1 + 2);
259 }
358934a6
SP		 260}
261
7fe0092b
BN		 262/**
263 * davinci_spi_get_prescale - Calculates the correct prescale value
264 * @maxspeed_hz: the maximum rate the SPI clock can run at
265 *
266 * This function calculates the prescale value that generates a clock rate
267 * less than or equal to the specified maximum.
268 *
269 * Returns: calculated prescale - 1 for easy programming into SPI registers
270 * or negative error number if valid prescalar cannot be updated.
271 */
272static inline int davinci_spi_get_prescale(struct davinci_spi *davinci_spi,
273 u32 max_speed_hz)
274{
275 int ret;
276
277 ret = DIV_ROUND_UP(clk_get_rate(davinci_spi->clk), max_speed_hz);
278
279 if (ret < 3 || ret > 256)
280 return -EINVAL;
281
282 return ret - 1;
283}
284
358934a6
SP		 285/**
286 * davinci_spi_setup_transfer - This functions will determine transfer method
287 * @spi: spi device on which data transfer to be done
288 * @t: spi transfer in which transfer info is filled
289 *
290 * This function determines data transfer method (8/16/32 bit transfer).
291 * It will also set the SPI Clock Control register according to
292 * SPI slave device freq.
293 */
294static int davinci_spi_setup_transfer(struct spi_device *spi,
295 struct spi_transfer *t)
296{
297
298 struct davinci_spi *davinci_spi;
25f33512 299 struct davinci_spi_config *spicfg;
358934a6 300 u8 bits_per_word = 0;
25f33512 301 u32 hz = 0, spifmt = 0, prescale = 0;
358934a6
SP		 302
303 davinci_spi = spi_master_get_devdata(spi->master);
25f33512
BN		 304 spicfg = (struct davinci_spi_config *)spi->controller_data;
305 if (!spicfg)
306 spicfg = &davinci_spi_default_cfg;
358934a6
SP		 307
308 if (t) {
309 bits_per_word = t->bits_per_word;
310 hz = t->speed_hz;
311 }
312
313 /* if bits_per_word is not set then set it default */
314 if (!bits_per_word)
315 bits_per_word = spi->bits_per_word;
316
317 /*
318 * Assign function pointer to appropriate transfer method
319 * 8bit, 16bit or 32bit transfer
320 */
321 if (bits_per_word <= 8 && bits_per_word >= 2) {
322 davinci_spi->get_rx = davinci_spi_rx_buf_u8;
323 davinci_spi->get_tx = davinci_spi_tx_buf_u8;
cda987eb 324 davinci_spi->bytes_per_word[spi->chip_select] = 1;
358934a6
SP		 325 } else if (bits_per_word <= 16 && bits_per_word >= 2) {
326 davinci_spi->get_rx = davinci_spi_rx_buf_u16;
327 davinci_spi->get_tx = davinci_spi_tx_buf_u16;
cda987eb 328 davinci_spi->bytes_per_word[spi->chip_select] = 2;
358934a6
SP		 329 } else
330 return -EINVAL;
331
332 if (!hz)
333 hz = spi->max_speed_hz;
334
25f33512
BN		 335 /* Set up SPIFMTn register, unique to this chipselect. */
336
7fe0092b
BN		 337 prescale = davinci_spi_get_prescale(davinci_spi, hz);
338 if (prescale < 0)
339 return prescale;
340
25f33512
BN		 341 spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
342
343 if (spi->mode & SPI_LSB_FIRST)
344 spifmt |= SPIFMT_SHIFTDIR_MASK;
345
346 if (spi->mode & SPI_CPOL)
347 spifmt |= SPIFMT_POLARITY_MASK;
348
349 if (!(spi->mode & SPI_CPHA))
350 spifmt |= SPIFMT_PHASE_MASK;
351
352 /*
353 * Version 1 hardware supports two basic SPI modes:
354 * - Standard SPI mode uses 4 pins, with chipselect
355 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
356 * (distinct from SPI_3WIRE, with just one data wire;
357 * or similar variants without MOSI or without MISO)
358 *
359 * Version 2 hardware supports an optional handshaking signal,
360 * so it can support two more modes:
361 * - 5 pin SPI variant is standard SPI plus SPI_READY
362 * - 4 pin with enable is (SPI_READY | SPI_NO_CS)
363 */
364
365 if (davinci_spi->version == SPI_VERSION_2) {
366
7abbf23c
BN		 367 u32 delay = 0;
368
25f33512
BN		 369 spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
370 & SPIFMT_WDELAY_MASK);
358934a6 371
25f33512
BN		 372 if (spicfg->odd_parity)
373 spifmt |= SPIFMT_ODD_PARITY_MASK;
374
375 if (spicfg->parity_enable)
376 spifmt |= SPIFMT_PARITYENA_MASK;
377
7abbf23c 378 if (spicfg->timer_disable) {
25f33512 379 spifmt |= SPIFMT_DISTIMER_MASK;
7abbf23c
BN		 380 } else {
381 delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
382 & SPIDELAY_C2TDELAY_MASK;
383 delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
384 & SPIDELAY_T2CDELAY_MASK;
385 }
25f33512 386
7abbf23c 387 if (spi->mode & SPI_READY) {
25f33512 388 spifmt |= SPIFMT_WAITENA_MASK;
7abbf23c
BN		 389 delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
390 & SPIDELAY_T2EDELAY_MASK;
391 delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
392 & SPIDELAY_C2EDELAY_MASK;
393 }
394
395 iowrite32(delay, davinci_spi->base + SPIDELAY);
25f33512
BN		 396 }
397
398 iowrite32(spifmt, davinci_spi->base + SPIFMT0);
358934a6
SP		 399
400 return 0;
401}
402
403static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data)
404{
405 struct spi_device *spi = (struct spi_device *)data;
406 struct davinci_spi *davinci_spi;
407 struct davinci_spi_dma *davinci_spi_dma;
358934a6
SP		 408
409 davinci_spi = spi_master_get_devdata(spi->master);
96fd881f 410 davinci_spi_dma = &davinci_spi->dma_channels;
358934a6
SP		 411
412 if (ch_status == DMA_COMPLETE)
413 edma_stop(davinci_spi_dma->dma_rx_channel);
414 else
415 edma_clean_channel(davinci_spi_dma->dma_rx_channel);
416
417 complete(&davinci_spi_dma->dma_rx_completion);
418 /* We must disable the DMA RX request */
419 davinci_spi_set_dma_req(spi, 0);
420}
421
422static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data)
423{
424 struct spi_device *spi = (struct spi_device *)data;
425 struct davinci_spi *davinci_spi;
426 struct davinci_spi_dma *davinci_spi_dma;
358934a6
SP		 427
428 davinci_spi = spi_master_get_devdata(spi->master);
96fd881f 429 davinci_spi_dma = &davinci_spi->dma_channels;
358934a6
SP		 430
431 if (ch_status == DMA_COMPLETE)
432 edma_stop(davinci_spi_dma->dma_tx_channel);
433 else
434 edma_clean_channel(davinci_spi_dma->dma_tx_channel);
435
436 complete(&davinci_spi_dma->dma_tx_completion);
437 /* We must disable the DMA TX request */
438 davinci_spi_set_dma_req(spi, 0);
439}
440
441static int davinci_spi_request_dma(struct spi_device *spi)
442{
443 struct davinci_spi *davinci_spi;
444 struct davinci_spi_dma *davinci_spi_dma;
358934a6
SP		 445 struct device *sdev;
446 int r;
447
448 davinci_spi = spi_master_get_devdata(spi->master);
96fd881f 449 davinci_spi_dma = &davinci_spi->dma_channels;
358934a6
SP		 450 sdev = davinci_spi->bitbang.master->dev.parent;
451
452 r = edma_alloc_channel(davinci_spi_dma->dma_rx_sync_dev,
453 davinci_spi_dma_rx_callback, spi,
454 davinci_spi_dma->eventq);
455 if (r < 0) {
456 dev_dbg(sdev, "Unable to request DMA channel for SPI RX\n");
457 return -EAGAIN;
458 }
459 davinci_spi_dma->dma_rx_channel = r;
460 r = edma_alloc_channel(davinci_spi_dma->dma_tx_sync_dev,
461 davinci_spi_dma_tx_callback, spi,
462 davinci_spi_dma->eventq);
463 if (r < 0) {
464 edma_free_channel(davinci_spi_dma->dma_rx_channel);
465 davinci_spi_dma->dma_rx_channel = -1;
466 dev_dbg(sdev, "Unable to request DMA channel for SPI TX\n");
467 return -EAGAIN;
468 }
469 davinci_spi_dma->dma_tx_channel = r;
470
471 return 0;
472}
473
474/**
475 * davinci_spi_setup - This functions will set default transfer method
476 * @spi: spi device on which data transfer to be done
477 *
478 * This functions sets the default transfer method.
479 */
358934a6
SP		 480static int davinci_spi_setup(struct spi_device *spi)
481{
b23a5d46 482 int retval = 0;
358934a6
SP		 483 struct davinci_spi *davinci_spi;
484 struct davinci_spi_dma *davinci_spi_dma;
be88471b 485 struct davinci_spi_platform_data *pdata;
358934a6
SP		 486
487 davinci_spi = spi_master_get_devdata(spi->master);
be88471b 488 pdata = davinci_spi->pdata;
358934a6
SP		 489
490 /* if bits per word length is zero then set it default 8 */
491 if (!spi->bits_per_word)
492 spi->bits_per_word = 8;
493
be88471b
BN		 494 if (!(spi->mode & SPI_NO_CS)) {
495 if ((pdata->chip_sel == NULL) ||
496 (pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS))
497 set_io_bits(davinci_spi->base + SPIPC0,
498 1 << spi->chip_select);
499
500 }
501
502 if (spi->mode & SPI_READY)
503 set_io_bits(davinci_spi->base + SPIPC0, SPIPC0_SPIENA_MASK);
504
505 if (spi->mode & SPI_LOOP)
506 set_io_bits(davinci_spi->base + SPIGCR1,
507 SPIGCR1_LOOPBACK_MASK);
508 else
509 clear_io_bits(davinci_spi->base + SPIGCR1,
510 SPIGCR1_LOOPBACK_MASK);
511
96fd881f
BN		 512 if (use_dma) {
513 davinci_spi_dma = &davinci_spi->dma_channels;
358934a6 514
b23a5d46
BN		 515 if ((davinci_spi_dma->dma_rx_channel == -1) ||
516 (davinci_spi_dma->dma_tx_channel == -1))
358934a6 517 retval = davinci_spi_request_dma(spi);
358934a6
SP		 518 }
519
358934a6
SP		 520 return retval;
521}
522
523static void davinci_spi_cleanup(struct spi_device *spi)
524{
96fd881f
BN		 525 if (use_dma) {
526 struct davinci_spi *davinci_spi =
527 spi_master_get_devdata(spi->master);
528 struct davinci_spi_dma *davinci_spi_dma =
529 &davinci_spi->dma_channels;
358934a6
SP		 530
531 if ((davinci_spi_dma->dma_rx_channel != -1)
532 && (davinci_spi_dma->dma_tx_channel != -1)) {
533 edma_free_channel(davinci_spi_dma->dma_tx_channel);
534 edma_free_channel(davinci_spi_dma->dma_rx_channel);
535 }
536 }
537}
538
358934a6
SP		 539static int davinci_spi_check_error(struct davinci_spi *davinci_spi,
540 int int_status)
541{
542 struct device *sdev = davinci_spi->bitbang.master->dev.parent;
543
544 if (int_status & SPIFLG_TIMEOUT_MASK) {
545 dev_dbg(sdev, "SPI Time-out Error\n");
546 return -ETIMEDOUT;
547 }
548 if (int_status & SPIFLG_DESYNC_MASK) {
549 dev_dbg(sdev, "SPI Desynchronization Error\n");
550 return -EIO;
551 }
552 if (int_status & SPIFLG_BITERR_MASK) {
553 dev_dbg(sdev, "SPI Bit error\n");
554 return -EIO;
555 }
556
557 if (davinci_spi->version == SPI_VERSION_2) {
558 if (int_status & SPIFLG_DLEN_ERR_MASK) {
559 dev_dbg(sdev, "SPI Data Length Error\n");
560 return -EIO;
561 }
562 if (int_status & SPIFLG_PARERR_MASK) {
563 dev_dbg(sdev, "SPI Parity Error\n");
564 return -EIO;
565 }
566 if (int_status & SPIFLG_OVRRUN_MASK) {
567 dev_dbg(sdev, "SPI Data Overrun error\n");
568 return -EIO;
569 }
358934a6
SP		 570 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
571 dev_dbg(sdev, "SPI Buffer Init Active\n");
572 return -EBUSY;
573 }
574 }
575
576 return 0;
577}
578
e0d205e9
BN		 579/**
580 * davinci_spi_process_events - check for and handle any SPI controller events
581 * @davinci_spi: the controller data
582 *
583 * This function will check the SPIFLG register and handle any events that are
584 * detected there
585 */
586static int davinci_spi_process_events(struct davinci_spi *davinci_spi)
587{
588 u32 buf, status, errors = 0, data1_reg_val;
589
590 buf = ioread32(davinci_spi->base + SPIBUF);
591
592 if (davinci_spi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) {
593 davinci_spi->get_rx(buf & 0xFFFF, davinci_spi);
594 davinci_spi->rcount--;
595 }
596
597 status = ioread32(davinci_spi->base + SPIFLG);
598
599 if (unlikely(status & SPIFLG_ERROR_MASK)) {
600 errors = status & SPIFLG_ERROR_MASK;
601 goto out;
602 }
603
604 if (davinci_spi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
605 data1_reg_val = ioread32(davinci_spi->base + SPIDAT1);
606 davinci_spi->wcount--;
607 data1_reg_val &= ~0xFFFF;
608 data1_reg_val |= 0xFFFF & davinci_spi->get_tx(davinci_spi);
609 iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
610 }
611
612out:
613 return errors;
614}
615
358934a6
SP		 616/**
617 * davinci_spi_bufs - functions which will handle transfer data
618 * @spi: spi device on which data transfer to be done
619 * @t: spi transfer in which transfer info is filled
620 *
621 * This function will put data to be transferred into data register
622 * of SPI controller and then wait until the completion will be marked
623 * by the IRQ Handler.
624 */
625static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
626{
627 struct davinci_spi *davinci_spi;
839c996c 628 int ret;
358934a6 629 u32 tx_data, data1_reg_val;
839c996c 630 u32 errors = 0;
e0d205e9 631 struct davinci_spi_config *spicfg;
358934a6
SP		 632 struct davinci_spi_platform_data *pdata;
633
634 davinci_spi = spi_master_get_devdata(spi->master);
635 pdata = davinci_spi->pdata;
e0d205e9
BN		 636 spicfg = (struct davinci_spi_config *)spi->controller_data;
637 if (!spicfg)
638 spicfg = &davinci_spi_default_cfg;
358934a6
SP		 639
640 davinci_spi->tx = t->tx_buf;
641 davinci_spi->rx = t->rx_buf;
e0d205e9
BN		 642 davinci_spi->wcount = t->len /
643 davinci_spi->bytes_per_word[spi->chip_select];
644 davinci_spi->rcount = davinci_spi->wcount;
7978b8c3 645
839c996c
BN		 646 data1_reg_val = ioread32(davinci_spi->base + SPIDAT1);
647
358934a6
SP		 648 /* Enable SPI */
649 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
650
e0d205e9
BN		 651 if (spicfg->io_type == SPI_IO_TYPE_INTR) {
652 set_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKINT);
653 INIT_COMPLETION(davinci_spi->done);
654 }
cf90fe73 655
839c996c 656 /* start the transfer */
e0d205e9 657 davinci_spi->wcount--;
839c996c
BN		 658 tx_data = davinci_spi->get_tx(davinci_spi);
659 data1_reg_val &= 0xFFFF0000;
660 data1_reg_val |= tx_data & 0xFFFF;
661 iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
358934a6 662
e0d205e9
BN		 663 /* Wait for the transfer to complete */
664 if (spicfg->io_type == SPI_IO_TYPE_INTR) {
665 wait_for_completion_interruptible(&(davinci_spi->done));
666 } else {
667 while (davinci_spi->rcount > 0 || davinci_spi->wcount > 0) {
668 errors = davinci_spi_process_events(davinci_spi);
669 if (errors)
670 break;
671 cpu_relax();
358934a6
SP		 672 }
673 }
674
e0d205e9
BN		 675 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
676
358934a6
SP		 677 /*
678 * Check for bit error, desync error,parity error,timeout error and
679 * receive overflow errors
680 */
839c996c
BN		 681 if (errors) {
682 ret = davinci_spi_check_error(davinci_spi, errors);
683 WARN(!ret, "%s: error reported but no error found!\n",
684 dev_name(&spi->dev));
358934a6 685 return ret;
839c996c 686 }
358934a6 687
358934a6
SP		 688 return t->len;
689}
690
e0d205e9
BN		 691/**
692 * davinci_spi_irq - Interrupt handler for SPI Master Controller
693 * @irq: IRQ number for this SPI Master
694 * @context_data: structure for SPI Master controller davinci_spi
695 *
696 * ISR will determine that interrupt arrives either for READ or WRITE command.
697 * According to command it will do the appropriate action. It will check
698 * transfer length and if it is not zero then dispatch transfer command again.
699 * If transfer length is zero then it will indicate the COMPLETION so that
700 * davinci_spi_bufs function can go ahead.
701 */
702static irqreturn_t davinci_spi_irq(s32 irq, void *context_data)
703{
704 struct davinci_spi *davinci_spi = context_data;
705 int status;
706
707 status = davinci_spi_process_events(davinci_spi);
708 if (unlikely(status != 0))
709 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKINT);
710
711 if ((!davinci_spi->rcount && !davinci_spi->wcount) || status)
712 complete(&davinci_spi->done);
713
714 return IRQ_HANDLED;
715}
716
358934a6
SP		 717static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
718{
719 struct davinci_spi *davinci_spi;
720 int int_status = 0;
721 int count, temp_count;
358934a6 722 struct davinci_spi_dma *davinci_spi_dma;
b7ab24a0 723 int data_type, ret;
358934a6 724 unsigned long tx_reg, rx_reg;
c29e3c60 725 struct davinci_spi_platform_data *pdata;
358934a6
SP		 726 struct device *sdev;
727
728 davinci_spi = spi_master_get_devdata(spi->master);
c29e3c60 729 pdata = davinci_spi->pdata;
358934a6
SP		 730 sdev = davinci_spi->bitbang.master->dev.parent;
731
96fd881f 732 davinci_spi_dma = &davinci_spi->dma_channels;
358934a6
SP		 733
734 tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1;
735 rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF;
736
737 davinci_spi->tx = t->tx_buf;
738 davinci_spi->rx = t->rx_buf;
739
740 /* convert len to words based on bits_per_word */
b7ab24a0 741 data_type = davinci_spi->bytes_per_word[spi->chip_select];
358934a6 742
358934a6
SP		 743 init_completion(&davinci_spi_dma->dma_rx_completion);
744 init_completion(&davinci_spi_dma->dma_tx_completion);
745
f2bf4e84 746 count = t->len / data_type; /* the number of elements */
358934a6
SP		 747
748 /* disable all interrupts for dma transfers */
749 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
358934a6
SP		 750 /* Enable SPI */
751 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
752
358934a6
SP		 753 if (t->tx_buf) {
754 t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count,
755 DMA_TO_DEVICE);
756 if (dma_mapping_error(&spi->dev, t->tx_dma)) {
757 dev_dbg(sdev, "Unable to DMA map a %d bytes"
758 " TX buffer\n", count);
759 return -ENOMEM;
760 }
761 temp_count = count;
762 } else {
763 /* We need TX clocking for RX transaction */
764 t->tx_dma = dma_map_single(&spi->dev,
765 (void *)davinci_spi->tmp_buf, count + 1,
766 DMA_TO_DEVICE);
767 if (dma_mapping_error(&spi->dev, t->tx_dma)) {
768 dev_dbg(sdev, "Unable to DMA map a %d bytes"
769 " TX tmp buffer\n", count);
770 return -ENOMEM;
771 }
772 temp_count = count + 1;
773 }
774
775 edma_set_transfer_params(davinci_spi_dma->dma_tx_channel,
776 data_type, temp_count, 1, 0, ASYNC);
777 edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT);
778 edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT);
779 edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0);
780 edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0);
781
782 if (t->rx_buf) {
358934a6
SP		 783 t->rx_dma = dma_map_single(&spi->dev, (void *)t->rx_buf, count,
784 DMA_FROM_DEVICE);
785 if (dma_mapping_error(&spi->dev, t->rx_dma)) {
786 dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
787 count);
788 if (t->tx_buf != NULL)
789 dma_unmap_single(NULL, t->tx_dma,
790 count, DMA_TO_DEVICE);
791 return -ENOMEM;
792 }
793 edma_set_transfer_params(davinci_spi_dma->dma_rx_channel,
794 data_type, count, 1, 0, ASYNC);
795 edma_set_src(davinci_spi_dma->dma_rx_channel,
796 rx_reg, INCR, W8BIT);
797 edma_set_dest(davinci_spi_dma->dma_rx_channel,
798 t->rx_dma, INCR, W8BIT);
799 edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0);
800 edma_set_dest_index(davinci_spi_dma->dma_rx_channel,
801 data_type, 0);
802 }
803
c29e3c60
BN		 804 if (pdata->cshold_bug) {
805 u16 spidat1 = ioread16(davinci_spi->base + SPIDAT1 + 2);
806 iowrite16(spidat1, davinci_spi->base + SPIDAT1 + 2);
807 }
358934a6
SP		 808
809 if (t->rx_buf)
810 edma_start(davinci_spi_dma->dma_rx_channel);
811
c29e3c60
BN		 812 edma_start(davinci_spi_dma->dma_tx_channel);
813 davinci_spi_set_dma_req(spi, 1);
358934a6 814
c29e3c60 815 wait_for_completion_interruptible(&davinci_spi_dma->dma_tx_completion);
358934a6
SP		 816
817 if (t->rx_buf)
818 wait_for_completion_interruptible(
819 &davinci_spi_dma->dma_rx_completion);
820
821 dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE);
822
823 if (t->rx_buf)
824 dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE);
825
826 /*
827 * Check for bit error, desync error,parity error,timeout error and
828 * receive overflow errors
829 */
830 int_status = ioread32(davinci_spi->base + SPIFLG);
831
832 ret = davinci_spi_check_error(davinci_spi, int_status);
833 if (ret != 0)
834 return ret;
835
358934a6
SP		 836 return t->len;
837}
838
358934a6
SP		 839/**
840 * davinci_spi_probe - probe function for SPI Master Controller
841 * @pdev: platform_device structure which contains plateform specific data
842 */
843static int davinci_spi_probe(struct platform_device *pdev)
844{
845 struct spi_master *master;
846 struct davinci_spi *davinci_spi;
847 struct davinci_spi_platform_data *pdata;
848 struct resource *r, *mem;
849 resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
850 resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
851 resource_size_t dma_eventq = SPI_NO_RESOURCE;
852 int i = 0, ret = 0;
f34bd4cc 853 u32 spipc0;
358934a6
SP		 854
855 pdata = pdev->dev.platform_data;
856 if (pdata == NULL) {
857 ret = -ENODEV;
858 goto err;
859 }
860
861 master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
862 if (master == NULL) {
863 ret = -ENOMEM;
864 goto err;
865 }
866
867 dev_set_drvdata(&pdev->dev, master);
868
869 davinci_spi = spi_master_get_devdata(master);
870 if (davinci_spi == NULL) {
871 ret = -ENOENT;
872 goto free_master;
873 }
874
875 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
876 if (r == NULL) {
877 ret = -ENOENT;
878 goto free_master;
879 }
880
881 davinci_spi->pbase = r->start;
882 davinci_spi->region_size = resource_size(r);
883 davinci_spi->pdata = pdata;
884
885 mem = request_mem_region(r->start, davinci_spi->region_size,
886 pdev->name);
887 if (mem == NULL) {
888 ret = -EBUSY;
889 goto free_master;
890 }
891
50356dd7 892 davinci_spi->base = ioremap(r->start, davinci_spi->region_size);
358934a6
SP		 893 if (davinci_spi->base == NULL) {
894 ret = -ENOMEM;
895 goto release_region;
896 }
897
e0d205e9
BN		 898 davinci_spi->irq = platform_get_irq(pdev, 0);
899 if (davinci_spi->irq <= 0) {
900 ret = -EINVAL;
901 goto unmap_io;
902 }
903
904 ret = request_irq(davinci_spi->irq, davinci_spi_irq, 0,
905 dev_name(&pdev->dev), davinci_spi);
906 if (ret)
907 goto unmap_io;
908
358934a6
SP		 909 /* Allocate tmp_buf for tx_buf */
910 davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL);
911 if (davinci_spi->tmp_buf == NULL) {
912 ret = -ENOMEM;
e0d205e9 913 goto irq_free;
358934a6
SP		 914 }
915
916 davinci_spi->bitbang.master = spi_master_get(master);
917 if (davinci_spi->bitbang.master == NULL) {
918 ret = -ENODEV;
919 goto free_tmp_buf;
920 }
921
922 davinci_spi->clk = clk_get(&pdev->dev, NULL);
923 if (IS_ERR(davinci_spi->clk)) {
924 ret = -ENODEV;
925 goto put_master;
926 }
927 clk_enable(davinci_spi->clk);
928
358934a6
SP		 929 master->bus_num = pdev->id;
930 master->num_chipselect = pdata->num_chipselect;
931 master->setup = davinci_spi_setup;
932 master->cleanup = davinci_spi_cleanup;
933
934 davinci_spi->bitbang.chipselect = davinci_spi_chipselect;
935 davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer;
936
937 davinci_spi->version = pdata->version;
938 use_dma = pdata->use_dma;
939
940 davinci_spi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
941 if (davinci_spi->version == SPI_VERSION_2)
942 davinci_spi->bitbang.flags |= SPI_READY;
943
944 if (use_dma) {
778e261e
BN		 945 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
946 if (r)
947 dma_rx_chan = r->start;
948 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
949 if (r)
950 dma_tx_chan = r->start;
951 r = platform_get_resource(pdev, IORESOURCE_DMA, 2);
952 if (r)
953 dma_eventq = r->start;
358934a6
SP		 954 }
955
956 if (!use_dma ||
957 dma_rx_chan == SPI_NO_RESOURCE ||
958 dma_tx_chan == SPI_NO_RESOURCE ||
959 dma_eventq == SPI_NO_RESOURCE) {
960 davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio;
961 use_dma = 0;
962 } else {
963 davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_dma;
358934a6 964
96fd881f
BN		 965 davinci_spi->dma_channels.dma_rx_channel = -1;
966 davinci_spi->dma_channels.dma_rx_sync_dev = dma_rx_chan;
967 davinci_spi->dma_channels.dma_tx_channel = -1;
968 davinci_spi->dma_channels.dma_tx_sync_dev = dma_tx_chan;
969 davinci_spi->dma_channels.eventq = dma_eventq;
970
358934a6
SP		 971 dev_info(&pdev->dev, "DaVinci SPI driver in EDMA mode\n"
972 "Using RX channel = %d , TX channel = %d and "
973 "event queue = %d", dma_rx_chan, dma_tx_chan,
974 dma_eventq);
975 }
976
977 davinci_spi->get_rx = davinci_spi_rx_buf_u8;
978 davinci_spi->get_tx = davinci_spi_tx_buf_u8;
979
e0d205e9
BN		 980 init_completion(&davinci_spi->done);
981
358934a6
SP		 982 /* Reset In/OUT SPI module */
983 iowrite32(0, davinci_spi->base + SPIGCR0);
984 udelay(100);
985 iowrite32(1, davinci_spi->base + SPIGCR0);
986
be88471b 987 /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */
f34bd4cc
BN		 988 spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK;
989 iowrite32(spipc0, davinci_spi->base + SPIPC0);
990
23853973
BN		 991 /* initialize chip selects */
992 if (pdata->chip_sel) {
993 for (i = 0; i < pdata->num_chipselect; i++) {
994 if (pdata->chip_sel[i] != SPI_INTERN_CS)
995 gpio_direction_output(pdata->chip_sel[i], 1);
996 }
997 }
998
358934a6
SP		 999 /* Clock internal */
1000 if (davinci_spi->pdata->clk_internal)
1001 set_io_bits(davinci_spi->base + SPIGCR1,
1002 SPIGCR1_CLKMOD_MASK);
1003 else
1004 clear_io_bits(davinci_spi->base + SPIGCR1,
1005 SPIGCR1_CLKMOD_MASK);
1006
e0d205e9
BN		 1007 if (pdata->intr_line)
1008 iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL);
1009 else
1010 iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL);
1011
843a713b
BN		 1012 iowrite32(CS_DEFAULT, davinci_spi->base + SPIDEF);
1013
358934a6
SP		 1014 /* master mode default */
1015 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
1016
358934a6
SP		 1017 ret = spi_bitbang_start(&davinci_spi->bitbang);
1018 if (ret)
1019 goto free_clk;
1020
3b740b10 1021 dev_info(&pdev->dev, "Controller at 0x%p\n", davinci_spi->base);
358934a6 1022
358934a6
SP		 1023 return ret;
1024
1025free_clk:
1026 clk_disable(davinci_spi->clk);
1027 clk_put(davinci_spi->clk);
1028put_master:
1029 spi_master_put(master);
1030free_tmp_buf:
1031 kfree(davinci_spi->tmp_buf);
e0d205e9
BN		 1032irq_free:
1033 free_irq(davinci_spi->irq, davinci_spi);
358934a6
SP		 1034unmap_io:
1035 iounmap(davinci_spi->base);
1036release_region:
1037 release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
1038free_master:
1039 kfree(master);
1040err:
1041 return ret;
1042}
1043
1044/**
1045 * davinci_spi_remove - remove function for SPI Master Controller
1046 * @pdev: platform_device structure which contains plateform specific data
1047 *
1048 * This function will do the reverse action of davinci_spi_probe function
1049 * It will free the IRQ and SPI controller's memory region.
1050 * It will also call spi_bitbang_stop to destroy the work queue which was
1051 * created by spi_bitbang_start.
1052 */
1053static int __exit davinci_spi_remove(struct platform_device *pdev)
1054{
1055 struct davinci_spi *davinci_spi;
1056 struct spi_master *master;
1057
1058 master = dev_get_drvdata(&pdev->dev);
1059 davinci_spi = spi_master_get_devdata(master);
1060
1061 spi_bitbang_stop(&davinci_spi->bitbang);
1062
1063 clk_disable(davinci_spi->clk);
1064 clk_put(davinci_spi->clk);
1065 spi_master_put(master);
1066 kfree(davinci_spi->tmp_buf);
e0d205e9 1067 free_irq(davinci_spi->irq, davinci_spi);
358934a6
SP		 1068 iounmap(davinci_spi->base);
1069 release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
1070
1071 return 0;
1072}
1073
1074static struct platform_driver davinci_spi_driver = {
1075 .driver.name = "spi_davinci",
1076 .remove = __exit_p(davinci_spi_remove),
1077};
1078
1079static int __init davinci_spi_init(void)
1080{
1081 return platform_driver_probe(&davinci_spi_driver, davinci_spi_probe);
1082}
1083module_init(davinci_spi_init);
1084
1085static void __exit davinci_spi_exit(void)
1086{
1087 platform_driver_unregister(&davinci_spi_driver);
1088}
1089module_exit(davinci_spi_exit);
1090
1091MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
1092MODULE_LICENSE("GPL");
Linux kernel - Deliverables
This page took 0.127752 seconds and 5 git commands to generate.