Staging: strip: delete the driver
[linux/fpc-iii.git] / drivers / spi / davinci_spi.c
blob95afb6b77395f3c60b4c8a18bafe2b4146369229
1 /*
2 * Copyright (C) 2009 Texas Instruments.
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.
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.
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
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>
30 #include <linux/slab.h>
32 #include <mach/spi.h>
33 #include <mach/edma.h>
35 #define SPI_NO_RESOURCE ((resource_size_t)-1)
37 #define SPI_MAX_CHIPSELECT 2
39 #define CS_DEFAULT 0xFF
41 #define SPI_BUFSIZ (SMP_CACHE_BYTES + 1)
42 #define DAVINCI_DMA_DATA_TYPE_S8 0x01
43 #define DAVINCI_DMA_DATA_TYPE_S16 0x02
44 #define DAVINCI_DMA_DATA_TYPE_S32 0x04
46 #define SPIFMT_PHASE_MASK BIT(16)
47 #define SPIFMT_POLARITY_MASK BIT(17)
48 #define SPIFMT_DISTIMER_MASK BIT(18)
49 #define SPIFMT_SHIFTDIR_MASK BIT(20)
50 #define SPIFMT_WAITENA_MASK BIT(21)
51 #define SPIFMT_PARITYENA_MASK BIT(22)
52 #define SPIFMT_ODD_PARITY_MASK BIT(23)
53 #define SPIFMT_WDELAY_MASK 0x3f000000u
54 #define SPIFMT_WDELAY_SHIFT 24
55 #define SPIFMT_CHARLEN_MASK 0x0000001Fu
57 /* SPIGCR1 */
58 #define SPIGCR1_SPIENA_MASK 0x01000000u
60 /* SPIPC0 */
61 #define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
62 #define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
63 #define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
64 #define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
65 #define SPIPC0_EN1FUN_MASK BIT(1)
66 #define SPIPC0_EN0FUN_MASK BIT(0)
68 #define SPIINT_MASKALL 0x0101035F
69 #define SPI_INTLVL_1 0x000001FFu
70 #define SPI_INTLVL_0 0x00000000u
72 /* SPIDAT1 */
73 #define SPIDAT1_CSHOLD_SHIFT 28
74 #define SPIDAT1_CSNR_SHIFT 16
75 #define SPIGCR1_CLKMOD_MASK BIT(1)
76 #define SPIGCR1_MASTER_MASK BIT(0)
77 #define SPIGCR1_LOOPBACK_MASK BIT(16)
79 /* SPIBUF */
80 #define SPIBUF_TXFULL_MASK BIT(29)
81 #define SPIBUF_RXEMPTY_MASK BIT(31)
83 /* Error Masks */
84 #define SPIFLG_DLEN_ERR_MASK BIT(0)
85 #define SPIFLG_TIMEOUT_MASK BIT(1)
86 #define SPIFLG_PARERR_MASK BIT(2)
87 #define SPIFLG_DESYNC_MASK BIT(3)
88 #define SPIFLG_BITERR_MASK BIT(4)
89 #define SPIFLG_OVRRUN_MASK BIT(6)
90 #define SPIFLG_RX_INTR_MASK BIT(8)
91 #define SPIFLG_TX_INTR_MASK BIT(9)
92 #define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
93 #define SPIFLG_MASK (SPIFLG_DLEN_ERR_MASK \
94 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
95 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
96 | SPIFLG_OVRRUN_MASK | SPIFLG_RX_INTR_MASK \
97 | SPIFLG_TX_INTR_MASK \
98 | SPIFLG_BUF_INIT_ACTIVE_MASK)
100 #define SPIINT_DLEN_ERR_INTR BIT(0)
101 #define SPIINT_TIMEOUT_INTR BIT(1)
102 #define SPIINT_PARERR_INTR BIT(2)
103 #define SPIINT_DESYNC_INTR BIT(3)
104 #define SPIINT_BITERR_INTR BIT(4)
105 #define SPIINT_OVRRUN_INTR BIT(6)
106 #define SPIINT_RX_INTR BIT(8)
107 #define SPIINT_TX_INTR BIT(9)
108 #define SPIINT_DMA_REQ_EN BIT(16)
109 #define SPIINT_ENABLE_HIGHZ BIT(24)
111 #define SPI_T2CDELAY_SHIFT 16
112 #define SPI_C2TDELAY_SHIFT 24
114 /* SPI Controller registers */
115 #define SPIGCR0 0x00
116 #define SPIGCR1 0x04
117 #define SPIINT 0x08
118 #define SPILVL 0x0c
119 #define SPIFLG 0x10
120 #define SPIPC0 0x14
121 #define SPIPC1 0x18
122 #define SPIPC2 0x1c
123 #define SPIPC3 0x20
124 #define SPIPC4 0x24
125 #define SPIPC5 0x28
126 #define SPIPC6 0x2c
127 #define SPIPC7 0x30
128 #define SPIPC8 0x34
129 #define SPIDAT0 0x38
130 #define SPIDAT1 0x3c
131 #define SPIBUF 0x40
132 #define SPIEMU 0x44
133 #define SPIDELAY 0x48
134 #define SPIDEF 0x4c
135 #define SPIFMT0 0x50
136 #define SPIFMT1 0x54
137 #define SPIFMT2 0x58
138 #define SPIFMT3 0x5c
139 #define TGINTVEC0 0x60
140 #define TGINTVEC1 0x64
142 struct davinci_spi_slave {
143 u32 cmd_to_write;
144 u32 clk_ctrl_to_write;
145 u32 bytes_per_word;
146 u8 active_cs;
149 /* We have 2 DMA channels per CS, one for RX and one for TX */
150 struct davinci_spi_dma {
151 int dma_tx_channel;
152 int dma_rx_channel;
153 int dma_tx_sync_dev;
154 int dma_rx_sync_dev;
155 enum dma_event_q eventq;
157 struct completion dma_tx_completion;
158 struct completion dma_rx_completion;
161 /* SPI Controller driver's private data. */
162 struct davinci_spi {
163 struct spi_bitbang bitbang;
164 struct clk *clk;
166 u8 version;
167 resource_size_t pbase;
168 void __iomem *base;
169 size_t region_size;
170 u32 irq;
171 struct completion done;
173 const void *tx;
174 void *rx;
175 u8 *tmp_buf;
176 int count;
177 struct davinci_spi_dma *dma_channels;
178 struct davinci_spi_platform_data *pdata;
180 void (*get_rx)(u32 rx_data, struct davinci_spi *);
181 u32 (*get_tx)(struct davinci_spi *);
183 struct davinci_spi_slave slave[SPI_MAX_CHIPSELECT];
186 static unsigned use_dma;
188 static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi)
190 u8 *rx = davinci_spi->rx;
192 *rx++ = (u8)data;
193 davinci_spi->rx = rx;
196 static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *davinci_spi)
198 u16 *rx = davinci_spi->rx;
200 *rx++ = (u16)data;
201 davinci_spi->rx = rx;
204 static u32 davinci_spi_tx_buf_u8(struct davinci_spi *davinci_spi)
206 u32 data;
207 const u8 *tx = davinci_spi->tx;
209 data = *tx++;
210 davinci_spi->tx = tx;
211 return data;
214 static u32 davinci_spi_tx_buf_u16(struct davinci_spi *davinci_spi)
216 u32 data;
217 const u16 *tx = davinci_spi->tx;
219 data = *tx++;
220 davinci_spi->tx = tx;
221 return data;
224 static inline void set_io_bits(void __iomem *addr, u32 bits)
226 u32 v = ioread32(addr);
228 v |= bits;
229 iowrite32(v, addr);
232 static inline void clear_io_bits(void __iomem *addr, u32 bits)
234 u32 v = ioread32(addr);
236 v &= ~bits;
237 iowrite32(v, addr);
240 static inline void set_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
242 set_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
245 static inline void clear_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
247 clear_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
250 static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable)
252 struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
254 if (enable)
255 set_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
256 else
257 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
261 * Interface to control the chip select signal
263 static void davinci_spi_chipselect(struct spi_device *spi, int value)
265 struct davinci_spi *davinci_spi;
266 struct davinci_spi_platform_data *pdata;
267 u32 data1_reg_val = 0;
269 davinci_spi = spi_master_get_devdata(spi->master);
270 pdata = davinci_spi->pdata;
273 * Board specific chip select logic decides the polarity and cs
274 * line for the controller
276 if (value == BITBANG_CS_INACTIVE) {
277 set_io_bits(davinci_spi->base + SPIDEF, CS_DEFAULT);
279 data1_reg_val |= CS_DEFAULT << SPIDAT1_CSNR_SHIFT;
280 iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
282 while ((ioread32(davinci_spi->base + SPIBUF)
283 & SPIBUF_RXEMPTY_MASK) == 0)
284 cpu_relax();
289 * davinci_spi_setup_transfer - This functions will determine transfer method
290 * @spi: spi device on which data transfer to be done
291 * @t: spi transfer in which transfer info is filled
293 * This function determines data transfer method (8/16/32 bit transfer).
294 * It will also set the SPI Clock Control register according to
295 * SPI slave device freq.
297 static int davinci_spi_setup_transfer(struct spi_device *spi,
298 struct spi_transfer *t)
301 struct davinci_spi *davinci_spi;
302 struct davinci_spi_platform_data *pdata;
303 u8 bits_per_word = 0;
304 u32 hz = 0, prescale;
306 davinci_spi = spi_master_get_devdata(spi->master);
307 pdata = davinci_spi->pdata;
309 if (t) {
310 bits_per_word = t->bits_per_word;
311 hz = t->speed_hz;
314 /* if bits_per_word is not set then set it default */
315 if (!bits_per_word)
316 bits_per_word = spi->bits_per_word;
319 * Assign function pointer to appropriate transfer method
320 * 8bit, 16bit or 32bit transfer
322 if (bits_per_word <= 8 && bits_per_word >= 2) {
323 davinci_spi->get_rx = davinci_spi_rx_buf_u8;
324 davinci_spi->get_tx = davinci_spi_tx_buf_u8;
325 davinci_spi->slave[spi->chip_select].bytes_per_word = 1;
326 } else if (bits_per_word <= 16 && bits_per_word >= 2) {
327 davinci_spi->get_rx = davinci_spi_rx_buf_u16;
328 davinci_spi->get_tx = davinci_spi_tx_buf_u16;
329 davinci_spi->slave[spi->chip_select].bytes_per_word = 2;
330 } else
331 return -EINVAL;
333 if (!hz)
334 hz = spi->max_speed_hz;
336 clear_fmt_bits(davinci_spi->base, SPIFMT_CHARLEN_MASK,
337 spi->chip_select);
338 set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f,
339 spi->chip_select);
341 prescale = ((clk_get_rate(davinci_spi->clk) / hz) - 1) & 0xff;
343 clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select);
344 set_fmt_bits(davinci_spi->base, prescale << 8, spi->chip_select);
346 return 0;
349 static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data)
351 struct spi_device *spi = (struct spi_device *)data;
352 struct davinci_spi *davinci_spi;
353 struct davinci_spi_dma *davinci_spi_dma;
354 struct davinci_spi_platform_data *pdata;
356 davinci_spi = spi_master_get_devdata(spi->master);
357 davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
358 pdata = davinci_spi->pdata;
360 if (ch_status == DMA_COMPLETE)
361 edma_stop(davinci_spi_dma->dma_rx_channel);
362 else
363 edma_clean_channel(davinci_spi_dma->dma_rx_channel);
365 complete(&davinci_spi_dma->dma_rx_completion);
366 /* We must disable the DMA RX request */
367 davinci_spi_set_dma_req(spi, 0);
370 static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data)
372 struct spi_device *spi = (struct spi_device *)data;
373 struct davinci_spi *davinci_spi;
374 struct davinci_spi_dma *davinci_spi_dma;
375 struct davinci_spi_platform_data *pdata;
377 davinci_spi = spi_master_get_devdata(spi->master);
378 davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
379 pdata = davinci_spi->pdata;
381 if (ch_status == DMA_COMPLETE)
382 edma_stop(davinci_spi_dma->dma_tx_channel);
383 else
384 edma_clean_channel(davinci_spi_dma->dma_tx_channel);
386 complete(&davinci_spi_dma->dma_tx_completion);
387 /* We must disable the DMA TX request */
388 davinci_spi_set_dma_req(spi, 0);
391 static int davinci_spi_request_dma(struct spi_device *spi)
393 struct davinci_spi *davinci_spi;
394 struct davinci_spi_dma *davinci_spi_dma;
395 struct davinci_spi_platform_data *pdata;
396 struct device *sdev;
397 int r;
399 davinci_spi = spi_master_get_devdata(spi->master);
400 davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
401 pdata = davinci_spi->pdata;
402 sdev = davinci_spi->bitbang.master->dev.parent;
404 r = edma_alloc_channel(davinci_spi_dma->dma_rx_sync_dev,
405 davinci_spi_dma_rx_callback, spi,
406 davinci_spi_dma->eventq);
407 if (r < 0) {
408 dev_dbg(sdev, "Unable to request DMA channel for SPI RX\n");
409 return -EAGAIN;
411 davinci_spi_dma->dma_rx_channel = r;
412 r = edma_alloc_channel(davinci_spi_dma->dma_tx_sync_dev,
413 davinci_spi_dma_tx_callback, spi,
414 davinci_spi_dma->eventq);
415 if (r < 0) {
416 edma_free_channel(davinci_spi_dma->dma_rx_channel);
417 davinci_spi_dma->dma_rx_channel = -1;
418 dev_dbg(sdev, "Unable to request DMA channel for SPI TX\n");
419 return -EAGAIN;
421 davinci_spi_dma->dma_tx_channel = r;
423 return 0;
427 * davinci_spi_setup - This functions will set default transfer method
428 * @spi: spi device on which data transfer to be done
430 * This functions sets the default transfer method.
433 static int davinci_spi_setup(struct spi_device *spi)
435 int retval;
436 struct davinci_spi *davinci_spi;
437 struct davinci_spi_dma *davinci_spi_dma;
438 struct device *sdev;
440 davinci_spi = spi_master_get_devdata(spi->master);
441 sdev = davinci_spi->bitbang.master->dev.parent;
443 /* if bits per word length is zero then set it default 8 */
444 if (!spi->bits_per_word)
445 spi->bits_per_word = 8;
447 davinci_spi->slave[spi->chip_select].cmd_to_write = 0;
449 if (use_dma && davinci_spi->dma_channels) {
450 davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
452 if ((davinci_spi_dma->dma_rx_channel == -1)
453 || (davinci_spi_dma->dma_tx_channel == -1)) {
454 retval = davinci_spi_request_dma(spi);
455 if (retval < 0)
456 return retval;
461 * SPI in DaVinci and DA8xx operate between
462 * 600 KHz and 50 MHz
464 if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000) {
465 dev_dbg(sdev, "Operating frequency is not in acceptable "
466 "range\n");
467 return -EINVAL;
471 * Set up SPIFMTn register, unique to this chipselect.
473 * NOTE: we could do all of these with one write. Also, some
474 * of the "version 2" features are found in chips that don't
475 * support all of them...
477 if (spi->mode & SPI_LSB_FIRST)
478 set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
479 spi->chip_select);
480 else
481 clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
482 spi->chip_select);
484 if (spi->mode & SPI_CPOL)
485 set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
486 spi->chip_select);
487 else
488 clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
489 spi->chip_select);
491 if (!(spi->mode & SPI_CPHA))
492 set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
493 spi->chip_select);
494 else
495 clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
496 spi->chip_select);
499 * Version 1 hardware supports two basic SPI modes:
500 * - Standard SPI mode uses 4 pins, with chipselect
501 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
502 * (distinct from SPI_3WIRE, with just one data wire;
503 * or similar variants without MOSI or without MISO)
505 * Version 2 hardware supports an optional handshaking signal,
506 * so it can support two more modes:
507 * - 5 pin SPI variant is standard SPI plus SPI_READY
508 * - 4 pin with enable is (SPI_READY | SPI_NO_CS)
511 if (davinci_spi->version == SPI_VERSION_2) {
512 clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
513 spi->chip_select);
514 set_fmt_bits(davinci_spi->base,
515 (davinci_spi->pdata->wdelay
516 << SPIFMT_WDELAY_SHIFT)
517 & SPIFMT_WDELAY_MASK,
518 spi->chip_select);
520 if (davinci_spi->pdata->odd_parity)
521 set_fmt_bits(davinci_spi->base,
522 SPIFMT_ODD_PARITY_MASK,
523 spi->chip_select);
524 else
525 clear_fmt_bits(davinci_spi->base,
526 SPIFMT_ODD_PARITY_MASK,
527 spi->chip_select);
529 if (davinci_spi->pdata->parity_enable)
530 set_fmt_bits(davinci_spi->base,
531 SPIFMT_PARITYENA_MASK,
532 spi->chip_select);
533 else
534 clear_fmt_bits(davinci_spi->base,
535 SPIFMT_PARITYENA_MASK,
536 spi->chip_select);
538 if (davinci_spi->pdata->wait_enable)
539 set_fmt_bits(davinci_spi->base,
540 SPIFMT_WAITENA_MASK,
541 spi->chip_select);
542 else
543 clear_fmt_bits(davinci_spi->base,
544 SPIFMT_WAITENA_MASK,
545 spi->chip_select);
547 if (davinci_spi->pdata->timer_disable)
548 set_fmt_bits(davinci_spi->base,
549 SPIFMT_DISTIMER_MASK,
550 spi->chip_select);
551 else
552 clear_fmt_bits(davinci_spi->base,
553 SPIFMT_DISTIMER_MASK,
554 spi->chip_select);
557 retval = davinci_spi_setup_transfer(spi, NULL);
559 return retval;
562 static void davinci_spi_cleanup(struct spi_device *spi)
564 struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
565 struct davinci_spi_dma *davinci_spi_dma;
567 davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
569 if (use_dma && davinci_spi->dma_channels) {
570 davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
572 if ((davinci_spi_dma->dma_rx_channel != -1)
573 && (davinci_spi_dma->dma_tx_channel != -1)) {
574 edma_free_channel(davinci_spi_dma->dma_tx_channel);
575 edma_free_channel(davinci_spi_dma->dma_rx_channel);
580 static int davinci_spi_bufs_prep(struct spi_device *spi,
581 struct davinci_spi *davinci_spi)
583 int op_mode = 0;
586 * REVISIT unless devices disagree about SPI_LOOP or
587 * SPI_READY (SPI_NO_CS only allows one device!), this
588 * should not need to be done before each message...
589 * optimize for both flags staying cleared.
592 op_mode = SPIPC0_DIFUN_MASK
593 | SPIPC0_DOFUN_MASK
594 | SPIPC0_CLKFUN_MASK;
595 if (!(spi->mode & SPI_NO_CS))
596 op_mode |= 1 << spi->chip_select;
597 if (spi->mode & SPI_READY)
598 op_mode |= SPIPC0_SPIENA_MASK;
600 iowrite32(op_mode, davinci_spi->base + SPIPC0);
602 if (spi->mode & SPI_LOOP)
603 set_io_bits(davinci_spi->base + SPIGCR1,
604 SPIGCR1_LOOPBACK_MASK);
605 else
606 clear_io_bits(davinci_spi->base + SPIGCR1,
607 SPIGCR1_LOOPBACK_MASK);
609 return 0;
612 static int davinci_spi_check_error(struct davinci_spi *davinci_spi,
613 int int_status)
615 struct device *sdev = davinci_spi->bitbang.master->dev.parent;
617 if (int_status & SPIFLG_TIMEOUT_MASK) {
618 dev_dbg(sdev, "SPI Time-out Error\n");
619 return -ETIMEDOUT;
621 if (int_status & SPIFLG_DESYNC_MASK) {
622 dev_dbg(sdev, "SPI Desynchronization Error\n");
623 return -EIO;
625 if (int_status & SPIFLG_BITERR_MASK) {
626 dev_dbg(sdev, "SPI Bit error\n");
627 return -EIO;
630 if (davinci_spi->version == SPI_VERSION_2) {
631 if (int_status & SPIFLG_DLEN_ERR_MASK) {
632 dev_dbg(sdev, "SPI Data Length Error\n");
633 return -EIO;
635 if (int_status & SPIFLG_PARERR_MASK) {
636 dev_dbg(sdev, "SPI Parity Error\n");
637 return -EIO;
639 if (int_status & SPIFLG_OVRRUN_MASK) {
640 dev_dbg(sdev, "SPI Data Overrun error\n");
641 return -EIO;
643 if (int_status & SPIFLG_TX_INTR_MASK) {
644 dev_dbg(sdev, "SPI TX intr bit set\n");
645 return -EIO;
647 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
648 dev_dbg(sdev, "SPI Buffer Init Active\n");
649 return -EBUSY;
653 return 0;
657 * davinci_spi_bufs - functions which will handle transfer data
658 * @spi: spi device on which data transfer to be done
659 * @t: spi transfer in which transfer info is filled
661 * This function will put data to be transferred into data register
662 * of SPI controller and then wait until the completion will be marked
663 * by the IRQ Handler.
665 static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
667 struct davinci_spi *davinci_spi;
668 int int_status, count, ret;
669 u8 conv, tmp;
670 u32 tx_data, data1_reg_val;
671 u32 buf_val, flg_val;
672 struct davinci_spi_platform_data *pdata;
674 davinci_spi = spi_master_get_devdata(spi->master);
675 pdata = davinci_spi->pdata;
677 davinci_spi->tx = t->tx_buf;
678 davinci_spi->rx = t->rx_buf;
680 /* convert len to words based on bits_per_word */
681 conv = davinci_spi->slave[spi->chip_select].bytes_per_word;
682 davinci_spi->count = t->len / conv;
684 INIT_COMPLETION(davinci_spi->done);
686 ret = davinci_spi_bufs_prep(spi, davinci_spi);
687 if (ret)
688 return ret;
690 /* Enable SPI */
691 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
693 iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
694 (pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
695 davinci_spi->base + SPIDELAY);
697 count = davinci_spi->count;
698 data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
699 tmp = ~(0x1 << spi->chip_select);
701 clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
703 data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
705 while ((ioread32(davinci_spi->base + SPIBUF)
706 & SPIBUF_RXEMPTY_MASK) == 0)
707 cpu_relax();
709 /* Determine the command to execute READ or WRITE */
710 if (t->tx_buf) {
711 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
713 while (1) {
714 tx_data = davinci_spi->get_tx(davinci_spi);
716 data1_reg_val &= ~(0xFFFF);
717 data1_reg_val |= (0xFFFF & tx_data);
719 buf_val = ioread32(davinci_spi->base + SPIBUF);
720 if ((buf_val & SPIBUF_TXFULL_MASK) == 0) {
721 iowrite32(data1_reg_val,
722 davinci_spi->base + SPIDAT1);
724 count--;
726 while (ioread32(davinci_spi->base + SPIBUF)
727 & SPIBUF_RXEMPTY_MASK)
728 cpu_relax();
730 /* getting the returned byte */
731 if (t->rx_buf) {
732 buf_val = ioread32(davinci_spi->base + SPIBUF);
733 davinci_spi->get_rx(buf_val, davinci_spi);
735 if (count <= 0)
736 break;
738 } else {
739 if (pdata->poll_mode) {
740 while (1) {
741 /* keeps the serial clock going */
742 if ((ioread32(davinci_spi->base + SPIBUF)
743 & SPIBUF_TXFULL_MASK) == 0)
744 iowrite32(data1_reg_val,
745 davinci_spi->base + SPIDAT1);
747 while (ioread32(davinci_spi->base + SPIBUF) &
748 SPIBUF_RXEMPTY_MASK)
749 cpu_relax();
751 flg_val = ioread32(davinci_spi->base + SPIFLG);
752 buf_val = ioread32(davinci_spi->base + SPIBUF);
754 davinci_spi->get_rx(buf_val, davinci_spi);
756 count--;
757 if (count <= 0)
758 break;
760 } else { /* Receive in Interrupt mode */
761 int i;
763 for (i = 0; i < davinci_spi->count; i++) {
764 set_io_bits(davinci_spi->base + SPIINT,
765 SPIINT_BITERR_INTR
766 | SPIINT_OVRRUN_INTR
767 | SPIINT_RX_INTR);
769 iowrite32(data1_reg_val,
770 davinci_spi->base + SPIDAT1);
772 while (ioread32(davinci_spi->base + SPIINT) &
773 SPIINT_RX_INTR)
774 cpu_relax();
776 iowrite32((data1_reg_val & 0x0ffcffff),
777 davinci_spi->base + SPIDAT1);
782 * Check for bit error, desync error,parity error,timeout error and
783 * receive overflow errors
785 int_status = ioread32(davinci_spi->base + SPIFLG);
787 ret = davinci_spi_check_error(davinci_spi, int_status);
788 if (ret != 0)
789 return ret;
791 /* SPI Framework maintains the count only in bytes so convert back */
792 davinci_spi->count *= conv;
794 return t->len;
797 #define DAVINCI_DMA_DATA_TYPE_S8 0x01
798 #define DAVINCI_DMA_DATA_TYPE_S16 0x02
799 #define DAVINCI_DMA_DATA_TYPE_S32 0x04
801 static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
803 struct davinci_spi *davinci_spi;
804 int int_status = 0;
805 int count, temp_count;
806 u8 conv = 1;
807 u8 tmp;
808 u32 data1_reg_val;
809 struct davinci_spi_dma *davinci_spi_dma;
810 int word_len, data_type, ret;
811 unsigned long tx_reg, rx_reg;
812 struct davinci_spi_platform_data *pdata;
813 struct device *sdev;
815 davinci_spi = spi_master_get_devdata(spi->master);
816 pdata = davinci_spi->pdata;
817 sdev = davinci_spi->bitbang.master->dev.parent;
819 davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
821 tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1;
822 rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF;
824 davinci_spi->tx = t->tx_buf;
825 davinci_spi->rx = t->rx_buf;
827 /* convert len to words based on bits_per_word */
828 conv = davinci_spi->slave[spi->chip_select].bytes_per_word;
829 davinci_spi->count = t->len / conv;
831 INIT_COMPLETION(davinci_spi->done);
833 init_completion(&davinci_spi_dma->dma_rx_completion);
834 init_completion(&davinci_spi_dma->dma_tx_completion);
836 word_len = conv * 8;
838 if (word_len <= 8)
839 data_type = DAVINCI_DMA_DATA_TYPE_S8;
840 else if (word_len <= 16)
841 data_type = DAVINCI_DMA_DATA_TYPE_S16;
842 else if (word_len <= 32)
843 data_type = DAVINCI_DMA_DATA_TYPE_S32;
844 else
845 return -EINVAL;
847 ret = davinci_spi_bufs_prep(spi, davinci_spi);
848 if (ret)
849 return ret;
851 /* Put delay val if required */
852 iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
853 (pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
854 davinci_spi->base + SPIDELAY);
856 count = davinci_spi->count; /* the number of elements */
857 data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
859 /* CS default = 0xFF */
860 tmp = ~(0x1 << spi->chip_select);
862 clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
864 data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
866 /* disable all interrupts for dma transfers */
867 clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
868 /* Disable SPI to write configuration bits in SPIDAT */
869 clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
870 iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
871 /* Enable SPI */
872 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
874 while ((ioread32(davinci_spi->base + SPIBUF)
875 & SPIBUF_RXEMPTY_MASK) == 0)
876 cpu_relax();
879 if (t->tx_buf) {
880 t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count,
881 DMA_TO_DEVICE);
882 if (dma_mapping_error(&spi->dev, t->tx_dma)) {
883 dev_dbg(sdev, "Unable to DMA map a %d bytes"
884 " TX buffer\n", count);
885 return -ENOMEM;
887 temp_count = count;
888 } else {
889 /* We need TX clocking for RX transaction */
890 t->tx_dma = dma_map_single(&spi->dev,
891 (void *)davinci_spi->tmp_buf, count + 1,
892 DMA_TO_DEVICE);
893 if (dma_mapping_error(&spi->dev, t->tx_dma)) {
894 dev_dbg(sdev, "Unable to DMA map a %d bytes"
895 " TX tmp buffer\n", count);
896 return -ENOMEM;
898 temp_count = count + 1;
901 edma_set_transfer_params(davinci_spi_dma->dma_tx_channel,
902 data_type, temp_count, 1, 0, ASYNC);
903 edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT);
904 edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT);
905 edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0);
906 edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0);
908 if (t->rx_buf) {
909 /* initiate transaction */
910 iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
912 t->rx_dma = dma_map_single(&spi->dev, (void *)t->rx_buf, count,
913 DMA_FROM_DEVICE);
914 if (dma_mapping_error(&spi->dev, t->rx_dma)) {
915 dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
916 count);
917 if (t->tx_buf != NULL)
918 dma_unmap_single(NULL, t->tx_dma,
919 count, DMA_TO_DEVICE);
920 return -ENOMEM;
922 edma_set_transfer_params(davinci_spi_dma->dma_rx_channel,
923 data_type, count, 1, 0, ASYNC);
924 edma_set_src(davinci_spi_dma->dma_rx_channel,
925 rx_reg, INCR, W8BIT);
926 edma_set_dest(davinci_spi_dma->dma_rx_channel,
927 t->rx_dma, INCR, W8BIT);
928 edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0);
929 edma_set_dest_index(davinci_spi_dma->dma_rx_channel,
930 data_type, 0);
933 if ((t->tx_buf) || (t->rx_buf))
934 edma_start(davinci_spi_dma->dma_tx_channel);
936 if (t->rx_buf)
937 edma_start(davinci_spi_dma->dma_rx_channel);
939 if ((t->rx_buf) || (t->tx_buf))
940 davinci_spi_set_dma_req(spi, 1);
942 if (t->tx_buf)
943 wait_for_completion_interruptible(
944 &davinci_spi_dma->dma_tx_completion);
946 if (t->rx_buf)
947 wait_for_completion_interruptible(
948 &davinci_spi_dma->dma_rx_completion);
950 dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE);
952 if (t->rx_buf)
953 dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE);
956 * Check for bit error, desync error,parity error,timeout error and
957 * receive overflow errors
959 int_status = ioread32(davinci_spi->base + SPIFLG);
961 ret = davinci_spi_check_error(davinci_spi, int_status);
962 if (ret != 0)
963 return ret;
965 /* SPI Framework maintains the count only in bytes so convert back */
966 davinci_spi->count *= conv;
968 return t->len;
972 * davinci_spi_irq - IRQ handler for DaVinci SPI
973 * @irq: IRQ number for this SPI Master
974 * @context_data: structure for SPI Master controller davinci_spi
976 static irqreturn_t davinci_spi_irq(s32 irq, void *context_data)
978 struct davinci_spi *davinci_spi = context_data;
979 u32 int_status, rx_data = 0;
980 irqreturn_t ret = IRQ_NONE;
982 int_status = ioread32(davinci_spi->base + SPIFLG);
984 while ((int_status & SPIFLG_RX_INTR_MASK)) {
985 if (likely(int_status & SPIFLG_RX_INTR_MASK)) {
986 ret = IRQ_HANDLED;
988 rx_data = ioread32(davinci_spi->base + SPIBUF);
989 davinci_spi->get_rx(rx_data, davinci_spi);
991 /* Disable Receive Interrupt */
992 iowrite32(~(SPIINT_RX_INTR | SPIINT_TX_INTR),
993 davinci_spi->base + SPIINT);
994 } else
995 (void)davinci_spi_check_error(davinci_spi, int_status);
997 int_status = ioread32(davinci_spi->base + SPIFLG);
1000 return ret;
1004 * davinci_spi_probe - probe function for SPI Master Controller
1005 * @pdev: platform_device structure which contains plateform specific data
1007 static int davinci_spi_probe(struct platform_device *pdev)
1009 struct spi_master *master;
1010 struct davinci_spi *davinci_spi;
1011 struct davinci_spi_platform_data *pdata;
1012 struct resource *r, *mem;
1013 resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
1014 resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
1015 resource_size_t dma_eventq = SPI_NO_RESOURCE;
1016 int i = 0, ret = 0;
1018 pdata = pdev->dev.platform_data;
1019 if (pdata == NULL) {
1020 ret = -ENODEV;
1021 goto err;
1024 master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
1025 if (master == NULL) {
1026 ret = -ENOMEM;
1027 goto err;
1030 dev_set_drvdata(&pdev->dev, master);
1032 davinci_spi = spi_master_get_devdata(master);
1033 if (davinci_spi == NULL) {
1034 ret = -ENOENT;
1035 goto free_master;
1038 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1039 if (r == NULL) {
1040 ret = -ENOENT;
1041 goto free_master;
1044 davinci_spi->pbase = r->start;
1045 davinci_spi->region_size = resource_size(r);
1046 davinci_spi->pdata = pdata;
1048 mem = request_mem_region(r->start, davinci_spi->region_size,
1049 pdev->name);
1050 if (mem == NULL) {
1051 ret = -EBUSY;
1052 goto free_master;
1055 davinci_spi->base = (struct davinci_spi_reg __iomem *)
1056 ioremap(r->start, davinci_spi->region_size);
1057 if (davinci_spi->base == NULL) {
1058 ret = -ENOMEM;
1059 goto release_region;
1062 davinci_spi->irq = platform_get_irq(pdev, 0);
1063 if (davinci_spi->irq <= 0) {
1064 ret = -EINVAL;
1065 goto unmap_io;
1068 ret = request_irq(davinci_spi->irq, davinci_spi_irq, IRQF_DISABLED,
1069 dev_name(&pdev->dev), davinci_spi);
1070 if (ret)
1071 goto unmap_io;
1073 /* Allocate tmp_buf for tx_buf */
1074 davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL);
1075 if (davinci_spi->tmp_buf == NULL) {
1076 ret = -ENOMEM;
1077 goto irq_free;
1080 davinci_spi->bitbang.master = spi_master_get(master);
1081 if (davinci_spi->bitbang.master == NULL) {
1082 ret = -ENODEV;
1083 goto free_tmp_buf;
1086 davinci_spi->clk = clk_get(&pdev->dev, NULL);
1087 if (IS_ERR(davinci_spi->clk)) {
1088 ret = -ENODEV;
1089 goto put_master;
1091 clk_enable(davinci_spi->clk);
1094 master->bus_num = pdev->id;
1095 master->num_chipselect = pdata->num_chipselect;
1096 master->setup = davinci_spi_setup;
1097 master->cleanup = davinci_spi_cleanup;
1099 davinci_spi->bitbang.chipselect = davinci_spi_chipselect;
1100 davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer;
1102 davinci_spi->version = pdata->version;
1103 use_dma = pdata->use_dma;
1105 davinci_spi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
1106 if (davinci_spi->version == SPI_VERSION_2)
1107 davinci_spi->bitbang.flags |= SPI_READY;
1109 if (use_dma) {
1110 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1111 if (r)
1112 dma_rx_chan = r->start;
1113 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
1114 if (r)
1115 dma_tx_chan = r->start;
1116 r = platform_get_resource(pdev, IORESOURCE_DMA, 2);
1117 if (r)
1118 dma_eventq = r->start;
1121 if (!use_dma ||
1122 dma_rx_chan == SPI_NO_RESOURCE ||
1123 dma_tx_chan == SPI_NO_RESOURCE ||
1124 dma_eventq == SPI_NO_RESOURCE) {
1125 davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio;
1126 use_dma = 0;
1127 } else {
1128 davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_dma;
1129 davinci_spi->dma_channels = kzalloc(master->num_chipselect
1130 * sizeof(struct davinci_spi_dma), GFP_KERNEL);
1131 if (davinci_spi->dma_channels == NULL) {
1132 ret = -ENOMEM;
1133 goto free_clk;
1136 for (i = 0; i < master->num_chipselect; i++) {
1137 davinci_spi->dma_channels[i].dma_rx_channel = -1;
1138 davinci_spi->dma_channels[i].dma_rx_sync_dev =
1139 dma_rx_chan;
1140 davinci_spi->dma_channels[i].dma_tx_channel = -1;
1141 davinci_spi->dma_channels[i].dma_tx_sync_dev =
1142 dma_tx_chan;
1143 davinci_spi->dma_channels[i].eventq = dma_eventq;
1145 dev_info(&pdev->dev, "DaVinci SPI driver in EDMA mode\n"
1146 "Using RX channel = %d , TX channel = %d and "
1147 "event queue = %d", dma_rx_chan, dma_tx_chan,
1148 dma_eventq);
1151 davinci_spi->get_rx = davinci_spi_rx_buf_u8;
1152 davinci_spi->get_tx = davinci_spi_tx_buf_u8;
1154 init_completion(&davinci_spi->done);
1156 /* Reset In/OUT SPI module */
1157 iowrite32(0, davinci_spi->base + SPIGCR0);
1158 udelay(100);
1159 iowrite32(1, davinci_spi->base + SPIGCR0);
1161 /* Clock internal */
1162 if (davinci_spi->pdata->clk_internal)
1163 set_io_bits(davinci_spi->base + SPIGCR1,
1164 SPIGCR1_CLKMOD_MASK);
1165 else
1166 clear_io_bits(davinci_spi->base + SPIGCR1,
1167 SPIGCR1_CLKMOD_MASK);
1169 /* master mode default */
1170 set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
1172 if (davinci_spi->pdata->intr_level)
1173 iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL);
1174 else
1175 iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL);
1177 ret = spi_bitbang_start(&davinci_spi->bitbang);
1178 if (ret)
1179 goto free_clk;
1181 dev_info(&pdev->dev, "Controller at 0x%p \n", davinci_spi->base);
1183 if (!pdata->poll_mode)
1184 dev_info(&pdev->dev, "Operating in interrupt mode"
1185 " using IRQ %d\n", davinci_spi->irq);
1187 return ret;
1189 free_clk:
1190 clk_disable(davinci_spi->clk);
1191 clk_put(davinci_spi->clk);
1192 put_master:
1193 spi_master_put(master);
1194 free_tmp_buf:
1195 kfree(davinci_spi->tmp_buf);
1196 irq_free:
1197 free_irq(davinci_spi->irq, davinci_spi);
1198 unmap_io:
1199 iounmap(davinci_spi->base);
1200 release_region:
1201 release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
1202 free_master:
1203 kfree(master);
1204 err:
1205 return ret;
1209 * davinci_spi_remove - remove function for SPI Master Controller
1210 * @pdev: platform_device structure which contains plateform specific data
1212 * This function will do the reverse action of davinci_spi_probe function
1213 * It will free the IRQ and SPI controller's memory region.
1214 * It will also call spi_bitbang_stop to destroy the work queue which was
1215 * created by spi_bitbang_start.
1217 static int __exit davinci_spi_remove(struct platform_device *pdev)
1219 struct davinci_spi *davinci_spi;
1220 struct spi_master *master;
1222 master = dev_get_drvdata(&pdev->dev);
1223 davinci_spi = spi_master_get_devdata(master);
1225 spi_bitbang_stop(&davinci_spi->bitbang);
1227 clk_disable(davinci_spi->clk);
1228 clk_put(davinci_spi->clk);
1229 spi_master_put(master);
1230 kfree(davinci_spi->tmp_buf);
1231 free_irq(davinci_spi->irq, davinci_spi);
1232 iounmap(davinci_spi->base);
1233 release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
1235 return 0;
1238 static struct platform_driver davinci_spi_driver = {
1239 .driver.name = "spi_davinci",
1240 .remove = __exit_p(davinci_spi_remove),
1243 static int __init davinci_spi_init(void)
1245 return platform_driver_probe(&davinci_spi_driver, davinci_spi_probe);
1247 module_init(davinci_spi_init);
1249 static void __exit davinci_spi_exit(void)
1251 platform_driver_unregister(&davinci_spi_driver);
1253 module_exit(davinci_spi_exit);
1255 MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
1256 MODULE_LICENSE("GPL");