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1/*
2 * Copyright (C) 2009 Texas Instruments.
3 * Copyright (C) 2010 EF Johnson Technologies
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/gpio.h>
19#include <linux/module.h>
20#include <linux/delay.h>
21#include <linux/platform_device.h>
22#include <linux/err.h>
23#include <linux/clk.h>
24#include <linux/dmaengine.h>
25#include <linux/dma-mapping.h>
26#include <linux/edma.h>
27#include <linux/of.h>
28#include <linux/of_device.h>
29#include <linux/of_gpio.h>
30#include <linux/spi/spi.h>
31#include <linux/spi/spi_bitbang.h>
32#include <linux/slab.h>
33
34#include <linux/platform_data/spi-davinci.h>
35
36#define SPI_NO_RESOURCE ((resource_size_t)-1)
37
38#define CS_DEFAULT 0xFF
39
40#define SPIFMT_PHASE_MASK BIT(16)
41#define SPIFMT_POLARITY_MASK BIT(17)
42#define SPIFMT_DISTIMER_MASK BIT(18)
43#define SPIFMT_SHIFTDIR_MASK BIT(20)
44#define SPIFMT_WAITENA_MASK BIT(21)
45#define SPIFMT_PARITYENA_MASK BIT(22)
46#define SPIFMT_ODD_PARITY_MASK BIT(23)
47#define SPIFMT_WDELAY_MASK 0x3f000000u
48#define SPIFMT_WDELAY_SHIFT 24
49#define SPIFMT_PRESCALE_SHIFT 8
50
51/* SPIPC0 */
52#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
53#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
54#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
55#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
56
57#define SPIINT_MASKALL 0x0101035F
58#define SPIINT_MASKINT 0x0000015F
59#define SPI_INTLVL_1 0x000001FF
60#define SPI_INTLVL_0 0x00000000
61
62/* SPIDAT1 (upper 16 bit defines) */
63#define SPIDAT1_CSHOLD_MASK BIT(12)
64#define SPIDAT1_WDEL BIT(10)
65
66/* SPIGCR1 */
67#define SPIGCR1_CLKMOD_MASK BIT(1)
68#define SPIGCR1_MASTER_MASK BIT(0)
69#define SPIGCR1_POWERDOWN_MASK BIT(8)
70#define SPIGCR1_LOOPBACK_MASK BIT(16)
71#define SPIGCR1_SPIENA_MASK BIT(24)
72
73/* SPIBUF */
74#define SPIBUF_TXFULL_MASK BIT(29)
75#define SPIBUF_RXEMPTY_MASK BIT(31)
76
77/* SPIDELAY */
78#define SPIDELAY_C2TDELAY_SHIFT 24
79#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
80#define SPIDELAY_T2CDELAY_SHIFT 16
81#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
82#define SPIDELAY_T2EDELAY_SHIFT 8
83#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
84#define SPIDELAY_C2EDELAY_SHIFT 0
85#define SPIDELAY_C2EDELAY_MASK 0xFF
86
87/* Error Masks */
88#define SPIFLG_DLEN_ERR_MASK BIT(0)
89#define SPIFLG_TIMEOUT_MASK BIT(1)
90#define SPIFLG_PARERR_MASK BIT(2)
91#define SPIFLG_DESYNC_MASK BIT(3)
92#define SPIFLG_BITERR_MASK BIT(4)
93#define SPIFLG_OVRRUN_MASK BIT(6)
94#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
95#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \
96 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
97 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
98 | SPIFLG_OVRRUN_MASK)
99
100#define SPIINT_DMA_REQ_EN BIT(16)
101
102/* SPI Controller registers */
103#define SPIGCR0 0x00
104#define SPIGCR1 0x04
105#define SPIINT 0x08
106#define SPILVL 0x0c
107#define SPIFLG 0x10
108#define SPIPC0 0x14
109#define SPIDAT1 0x3c
110#define SPIBUF 0x40
111#define SPIDELAY 0x48
112#define SPIDEF 0x4c
113#define SPIFMT0 0x50
114
115/* SPI Controller driver's private data. */
116struct davinci_spi {
117 struct spi_bitbang bitbang;
118 struct clk *clk;
119
120 u8 version;
121 resource_size_t pbase;
122 void __iomem *base;
123 u32 irq;
124 struct completion done;
125
126 const void *tx;
127 void *rx;
128 int rcount;
129 int wcount;
130
131 struct dma_chan *dma_rx;
132 struct dma_chan *dma_tx;
133 int dma_rx_chnum;
134 int dma_tx_chnum;
135
136 struct davinci_spi_platform_data pdata;
137
138 void (*get_rx)(u32 rx_data, struct davinci_spi *);
139 u32 (*get_tx)(struct davinci_spi *);
140
141 u8 *bytes_per_word;
142
143 u8 prescaler_limit;
144};
145
146static struct davinci_spi_config davinci_spi_default_cfg;
147
148static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi)
149{
150 if (dspi->rx) {
151 u8 *rx = dspi->rx;
152 *rx++ = (u8)data;
153 dspi->rx = rx;
154 }
155}
156
157static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi)
158{
159 if (dspi->rx) {
160 u16 *rx = dspi->rx;
161 *rx++ = (u16)data;
162 dspi->rx = rx;
163 }
164}
165
166static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi)
167{
168 u32 data = 0;
169
170 if (dspi->tx) {
171 const u8 *tx = dspi->tx;
172
173 data = *tx++;
174 dspi->tx = tx;
175 }
176 return data;
177}
178
179static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi)
180{
181 u32 data = 0;
182
183 if (dspi->tx) {
184 const u16 *tx = dspi->tx;
185
186 data = *tx++;
187 dspi->tx = tx;
188 }
189 return data;
190}
191
192static inline void set_io_bits(void __iomem *addr, u32 bits)
193{
194 u32 v = ioread32(addr);
195
196 v |= bits;
197 iowrite32(v, addr);
198}
199
200static inline void clear_io_bits(void __iomem *addr, u32 bits)
201{
202 u32 v = ioread32(addr);
203
204 v &= ~bits;
205 iowrite32(v, addr);
206}
207
208/*
209 * Interface to control the chip select signal
210 */
211static void davinci_spi_chipselect(struct spi_device *spi, int value)
212{
213 struct davinci_spi *dspi;
214 struct davinci_spi_platform_data *pdata;
215 struct davinci_spi_config *spicfg = spi->controller_data;
216 u8 chip_sel = spi->chip_select;
217 u16 spidat1 = CS_DEFAULT;
218
219 dspi = spi_master_get_devdata(spi->master);
220 pdata = &dspi->pdata;
221
222 /* program delay transfers if tx_delay is non zero */
223 if (spicfg->wdelay)
224 spidat1 |= SPIDAT1_WDEL;
225
226 /*
227 * Board specific chip select logic decides the polarity and cs
228 * line for the controller
229 */
230 if (spi->cs_gpio >= 0) {
231 if (value == BITBANG_CS_ACTIVE)
232 gpio_set_value(spi->cs_gpio, spi->mode & SPI_CS_HIGH);
233 else
234 gpio_set_value(spi->cs_gpio,
235 !(spi->mode & SPI_CS_HIGH));
236 } else {
237 if (value == BITBANG_CS_ACTIVE) {
238 spidat1 |= SPIDAT1_CSHOLD_MASK;
239 spidat1 &= ~(0x1 << chip_sel);
240 }
241 }
242
243 iowrite16(spidat1, dspi->base + SPIDAT1 + 2);
244}
245
246/**
247 * davinci_spi_get_prescale - Calculates the correct prescale value
248 * @maxspeed_hz: the maximum rate the SPI clock can run at
249 *
250 * This function calculates the prescale value that generates a clock rate
251 * less than or equal to the specified maximum.
252 *
253 * Returns: calculated prescale value for easy programming into SPI registers
254 * or negative error number if valid prescalar cannot be updated.
255 */
256static inline int davinci_spi_get_prescale(struct davinci_spi *dspi,
257 u32 max_speed_hz)
258{
259 int ret;
260
261 /* Subtract 1 to match what will be programmed into SPI register. */
262 ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1;
263
264 if (ret < dspi->prescaler_limit || ret > 255)
265 return -EINVAL;
266
267 return ret;
268}
269
270/**
271 * davinci_spi_setup_transfer - This functions will determine transfer method
272 * @spi: spi device on which data transfer to be done
273 * @t: spi transfer in which transfer info is filled
274 *
275 * This function determines data transfer method (8/16/32 bit transfer).
276 * It will also set the SPI Clock Control register according to
277 * SPI slave device freq.
278 */
279static int davinci_spi_setup_transfer(struct spi_device *spi,
280 struct spi_transfer *t)
281{
282
283 struct davinci_spi *dspi;
284 struct davinci_spi_config *spicfg;
285 u8 bits_per_word = 0;
286 u32 hz = 0, spifmt = 0;
287 int prescale;
288
289 dspi = spi_master_get_devdata(spi->master);
290 spicfg = spi->controller_data;
291 if (!spicfg)
292 spicfg = &davinci_spi_default_cfg;
293
294 if (t) {
295 bits_per_word = t->bits_per_word;
296 hz = t->speed_hz;
297 }
298
299 /* if bits_per_word is not set then set it default */
300 if (!bits_per_word)
301 bits_per_word = spi->bits_per_word;
302
303 /*
304 * Assign function pointer to appropriate transfer method
305 * 8bit, 16bit or 32bit transfer
306 */
307 if (bits_per_word <= 8) {
308 dspi->get_rx = davinci_spi_rx_buf_u8;
309 dspi->get_tx = davinci_spi_tx_buf_u8;
310 dspi->bytes_per_word[spi->chip_select] = 1;
311 } else {
312 dspi->get_rx = davinci_spi_rx_buf_u16;
313 dspi->get_tx = davinci_spi_tx_buf_u16;
314 dspi->bytes_per_word[spi->chip_select] = 2;
315 }
316
317 if (!hz)
318 hz = spi->max_speed_hz;
319
320 /* Set up SPIFMTn register, unique to this chipselect. */
321
322 prescale = davinci_spi_get_prescale(dspi, hz);
323 if (prescale < 0)
324 return prescale;
325
326 spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
327
328 if (spi->mode & SPI_LSB_FIRST)
329 spifmt |= SPIFMT_SHIFTDIR_MASK;
330
331 if (spi->mode & SPI_CPOL)
332 spifmt |= SPIFMT_POLARITY_MASK;
333
334 if (!(spi->mode & SPI_CPHA))
335 spifmt |= SPIFMT_PHASE_MASK;
336
337 /*
338 * Assume wdelay is used only on SPI peripherals that has this field
339 * in SPIFMTn register and when it's configured from board file or DT.
340 */
341 if (spicfg->wdelay)
342 spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
343 & SPIFMT_WDELAY_MASK);
344
345 /*
346 * Version 1 hardware supports two basic SPI modes:
347 * - Standard SPI mode uses 4 pins, with chipselect
348 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
349 * (distinct from SPI_3WIRE, with just one data wire;
350 * or similar variants without MOSI or without MISO)
351 *
352 * Version 2 hardware supports an optional handshaking signal,
353 * so it can support two more modes:
354 * - 5 pin SPI variant is standard SPI plus SPI_READY
355 * - 4 pin with enable is (SPI_READY | SPI_NO_CS)
356 */
357
358 if (dspi->version == SPI_VERSION_2) {
359
360 u32 delay = 0;
361
362 if (spicfg->odd_parity)
363 spifmt |= SPIFMT_ODD_PARITY_MASK;
364
365 if (spicfg->parity_enable)
366 spifmt |= SPIFMT_PARITYENA_MASK;
367
368 if (spicfg->timer_disable) {
369 spifmt |= SPIFMT_DISTIMER_MASK;
370 } else {
371 delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
372 & SPIDELAY_C2TDELAY_MASK;
373 delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
374 & SPIDELAY_T2CDELAY_MASK;
375 }
376
377 if (spi->mode & SPI_READY) {
378 spifmt |= SPIFMT_WAITENA_MASK;
379 delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
380 & SPIDELAY_T2EDELAY_MASK;
381 delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
382 & SPIDELAY_C2EDELAY_MASK;
383 }
384
385 iowrite32(delay, dspi->base + SPIDELAY);
386 }
387
388 iowrite32(spifmt, dspi->base + SPIFMT0);
389
390 return 0;
391}
392
393static int davinci_spi_of_setup(struct spi_device *spi)
394{
395 struct davinci_spi_config *spicfg = spi->controller_data;
396 struct device_node *np = spi->dev.of_node;
397 u32 prop;
398
399 if (spicfg == NULL && np) {
400 spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL);
401 if (!spicfg)
402 return -ENOMEM;
403 *spicfg = davinci_spi_default_cfg;
404 /* override with dt configured values */
405 if (!of_property_read_u32(np, "ti,spi-wdelay", &prop))
406 spicfg->wdelay = (u8)prop;
407 spi->controller_data = spicfg;
408 }
409
410 return 0;
411}
412
413/**
414 * davinci_spi_setup - This functions will set default transfer method
415 * @spi: spi device on which data transfer to be done
416 *
417 * This functions sets the default transfer method.
418 */
419static int davinci_spi_setup(struct spi_device *spi)
420{
421 int retval = 0;
422 struct davinci_spi *dspi;
423 struct davinci_spi_platform_data *pdata;
424 struct spi_master *master = spi->master;
425 struct device_node *np = spi->dev.of_node;
426 bool internal_cs = true;
427
428 dspi = spi_master_get_devdata(spi->master);
429 pdata = &dspi->pdata;
430
431 if (!(spi->mode & SPI_NO_CS)) {
432 if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) {
433 retval = gpio_direction_output(
434 spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
435 internal_cs = false;
436 } else if (pdata->chip_sel &&
437 spi->chip_select < pdata->num_chipselect &&
438 pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) {
439 spi->cs_gpio = pdata->chip_sel[spi->chip_select];
440 retval = gpio_direction_output(
441 spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
442 internal_cs = false;
443 }
444
445 if (retval) {
446 dev_err(&spi->dev, "GPIO %d setup failed (%d)\n",
447 spi->cs_gpio, retval);
448 return retval;
449 }
450
451 if (internal_cs)
452 set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select);
453 }
454
455 if (spi->mode & SPI_READY)
456 set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK);
457
458 if (spi->mode & SPI_LOOP)
459 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
460 else
461 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
462
463 return davinci_spi_of_setup(spi);
464}
465
466static void davinci_spi_cleanup(struct spi_device *spi)
467{
468 struct davinci_spi_config *spicfg = spi->controller_data;
469
470 spi->controller_data = NULL;
471 if (spi->dev.of_node)
472 kfree(spicfg);
473}
474
475static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status)
476{
477 struct device *sdev = dspi->bitbang.master->dev.parent;
478
479 if (int_status & SPIFLG_TIMEOUT_MASK) {
480 dev_err(sdev, "SPI Time-out Error\n");
481 return -ETIMEDOUT;
482 }
483 if (int_status & SPIFLG_DESYNC_MASK) {
484 dev_err(sdev, "SPI Desynchronization Error\n");
485 return -EIO;
486 }
487 if (int_status & SPIFLG_BITERR_MASK) {
488 dev_err(sdev, "SPI Bit error\n");
489 return -EIO;
490 }
491
492 if (dspi->version == SPI_VERSION_2) {
493 if (int_status & SPIFLG_DLEN_ERR_MASK) {
494 dev_err(sdev, "SPI Data Length Error\n");
495 return -EIO;
496 }
497 if (int_status & SPIFLG_PARERR_MASK) {
498 dev_err(sdev, "SPI Parity Error\n");
499 return -EIO;
500 }
501 if (int_status & SPIFLG_OVRRUN_MASK) {
502 dev_err(sdev, "SPI Data Overrun error\n");
503 return -EIO;
504 }
505 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
506 dev_err(sdev, "SPI Buffer Init Active\n");
507 return -EBUSY;
508 }
509 }
510
511 return 0;
512}
513
514/**
515 * davinci_spi_process_events - check for and handle any SPI controller events
516 * @dspi: the controller data
517 *
518 * This function will check the SPIFLG register and handle any events that are
519 * detected there
520 */
521static int davinci_spi_process_events(struct davinci_spi *dspi)
522{
523 u32 buf, status, errors = 0, spidat1;
524
525 buf = ioread32(dspi->base + SPIBUF);
526
527 if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) {
528 dspi->get_rx(buf & 0xFFFF, dspi);
529 dspi->rcount--;
530 }
531
532 status = ioread32(dspi->base + SPIFLG);
533
534 if (unlikely(status & SPIFLG_ERROR_MASK)) {
535 errors = status & SPIFLG_ERROR_MASK;
536 goto out;
537 }
538
539 if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
540 spidat1 = ioread32(dspi->base + SPIDAT1);
541 dspi->wcount--;
542 spidat1 &= ~0xFFFF;
543 spidat1 |= 0xFFFF & dspi->get_tx(dspi);
544 iowrite32(spidat1, dspi->base + SPIDAT1);
545 }
546
547out:
548 return errors;
549}
550
551static void davinci_spi_dma_rx_callback(void *data)
552{
553 struct davinci_spi *dspi = (struct davinci_spi *)data;
554
555 dspi->rcount = 0;
556
557 if (!dspi->wcount && !dspi->rcount)
558 complete(&dspi->done);
559}
560
561static void davinci_spi_dma_tx_callback(void *data)
562{
563 struct davinci_spi *dspi = (struct davinci_spi *)data;
564
565 dspi->wcount = 0;
566
567 if (!dspi->wcount && !dspi->rcount)
568 complete(&dspi->done);
569}
570
571/**
572 * davinci_spi_bufs - functions which will handle transfer data
573 * @spi: spi device on which data transfer to be done
574 * @t: spi transfer in which transfer info is filled
575 *
576 * This function will put data to be transferred into data register
577 * of SPI controller and then wait until the completion will be marked
578 * by the IRQ Handler.
579 */
580static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
581{
582 struct davinci_spi *dspi;
583 int data_type, ret = -ENOMEM;
584 u32 tx_data, spidat1;
585 u32 errors = 0;
586 struct davinci_spi_config *spicfg;
587 struct davinci_spi_platform_data *pdata;
588 unsigned uninitialized_var(rx_buf_count);
589 void *dummy_buf = NULL;
590 struct scatterlist sg_rx, sg_tx;
591
592 dspi = spi_master_get_devdata(spi->master);
593 pdata = &dspi->pdata;
594 spicfg = (struct davinci_spi_config *)spi->controller_data;
595 if (!spicfg)
596 spicfg = &davinci_spi_default_cfg;
597
598 /* convert len to words based on bits_per_word */
599 data_type = dspi->bytes_per_word[spi->chip_select];
600
601 dspi->tx = t->tx_buf;
602 dspi->rx = t->rx_buf;
603 dspi->wcount = t->len / data_type;
604 dspi->rcount = dspi->wcount;
605
606 spidat1 = ioread32(dspi->base + SPIDAT1);
607
608 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
609 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
610
611 reinit_completion(&dspi->done);
612
613 if (spicfg->io_type == SPI_IO_TYPE_INTR)
614 set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
615
616 if (spicfg->io_type != SPI_IO_TYPE_DMA) {
617 /* start the transfer */
618 dspi->wcount--;
619 tx_data = dspi->get_tx(dspi);
620 spidat1 &= 0xFFFF0000;
621 spidat1 |= tx_data & 0xFFFF;
622 iowrite32(spidat1, dspi->base + SPIDAT1);
623 } else {
624 struct dma_slave_config dma_rx_conf = {
625 .direction = DMA_DEV_TO_MEM,
626 .src_addr = (unsigned long)dspi->pbase + SPIBUF,
627 .src_addr_width = data_type,
628 .src_maxburst = 1,
629 };
630 struct dma_slave_config dma_tx_conf = {
631 .direction = DMA_MEM_TO_DEV,
632 .dst_addr = (unsigned long)dspi->pbase + SPIDAT1,
633 .dst_addr_width = data_type,
634 .dst_maxburst = 1,
635 };
636 struct dma_async_tx_descriptor *rxdesc;
637 struct dma_async_tx_descriptor *txdesc;
638 void *buf;
639
640 dummy_buf = kzalloc(t->len, GFP_KERNEL);
641 if (!dummy_buf)
642 goto err_alloc_dummy_buf;
643
644 dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf);
645 dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf);
646
647 sg_init_table(&sg_rx, 1);
648 if (!t->rx_buf)
649 buf = dummy_buf;
650 else
651 buf = t->rx_buf;
652 t->rx_dma = dma_map_single(&spi->dev, buf,
653 t->len, DMA_FROM_DEVICE);
654 if (!t->rx_dma) {
655 ret = -EFAULT;
656 goto err_rx_map;
657 }
658 sg_dma_address(&sg_rx) = t->rx_dma;
659 sg_dma_len(&sg_rx) = t->len;
660
661 sg_init_table(&sg_tx, 1);
662 if (!t->tx_buf)
663 buf = dummy_buf;
664 else
665 buf = (void *)t->tx_buf;
666 t->tx_dma = dma_map_single(&spi->dev, buf,
667 t->len, DMA_TO_DEVICE);
668 if (!t->tx_dma) {
669 ret = -EFAULT;
670 goto err_tx_map;
671 }
672 sg_dma_address(&sg_tx) = t->tx_dma;
673 sg_dma_len(&sg_tx) = t->len;
674
675 rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx,
676 &sg_rx, 1, DMA_DEV_TO_MEM,
677 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
678 if (!rxdesc)
679 goto err_desc;
680
681 txdesc = dmaengine_prep_slave_sg(dspi->dma_tx,
682 &sg_tx, 1, DMA_MEM_TO_DEV,
683 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
684 if (!txdesc)
685 goto err_desc;
686
687 rxdesc->callback = davinci_spi_dma_rx_callback;
688 rxdesc->callback_param = (void *)dspi;
689 txdesc->callback = davinci_spi_dma_tx_callback;
690 txdesc->callback_param = (void *)dspi;
691
692 if (pdata->cshold_bug)
693 iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2);
694
695 dmaengine_submit(rxdesc);
696 dmaengine_submit(txdesc);
697
698 dma_async_issue_pending(dspi->dma_rx);
699 dma_async_issue_pending(dspi->dma_tx);
700
701 set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
702 }
703
704 /* Wait for the transfer to complete */
705 if (spicfg->io_type != SPI_IO_TYPE_POLL) {
706 if (wait_for_completion_timeout(&dspi->done, HZ) == 0)
707 errors = SPIFLG_TIMEOUT_MASK;
708 } else {
709 while (dspi->rcount > 0 || dspi->wcount > 0) {
710 errors = davinci_spi_process_events(dspi);
711 if (errors)
712 break;
713 cpu_relax();
714 }
715 }
716
717 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL);
718 if (spicfg->io_type == SPI_IO_TYPE_DMA) {
719 clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
720
721 dma_unmap_single(&spi->dev, t->rx_dma,
722 t->len, DMA_FROM_DEVICE);
723 dma_unmap_single(&spi->dev, t->tx_dma,
724 t->len, DMA_TO_DEVICE);
725 kfree(dummy_buf);
726 }
727
728 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
729 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
730
731 /*
732 * Check for bit error, desync error,parity error,timeout error and
733 * receive overflow errors
734 */
735 if (errors) {
736 ret = davinci_spi_check_error(dspi, errors);
737 WARN(!ret, "%s: error reported but no error found!\n",
738 dev_name(&spi->dev));
739 return ret;
740 }
741
742 if (dspi->rcount != 0 || dspi->wcount != 0) {
743 dev_err(&spi->dev, "SPI data transfer error\n");
744 return -EIO;
745 }
746
747 return t->len;
748
749err_desc:
750 dma_unmap_single(&spi->dev, t->tx_dma, t->len, DMA_TO_DEVICE);
751err_tx_map:
752 dma_unmap_single(&spi->dev, t->rx_dma, t->len, DMA_FROM_DEVICE);
753err_rx_map:
754 kfree(dummy_buf);
755err_alloc_dummy_buf:
756 return ret;
757}
758
759/**
760 * dummy_thread_fn - dummy thread function
761 * @irq: IRQ number for this SPI Master
762 * @context_data: structure for SPI Master controller davinci_spi
763 *
764 * This is to satisfy the request_threaded_irq() API so that the irq
765 * handler is called in interrupt context.
766 */
767static irqreturn_t dummy_thread_fn(s32 irq, void *data)
768{
769 return IRQ_HANDLED;
770}
771
772/**
773 * davinci_spi_irq - Interrupt handler for SPI Master Controller
774 * @irq: IRQ number for this SPI Master
775 * @context_data: structure for SPI Master controller davinci_spi
776 *
777 * ISR will determine that interrupt arrives either for READ or WRITE command.
778 * According to command it will do the appropriate action. It will check
779 * transfer length and if it is not zero then dispatch transfer command again.
780 * If transfer length is zero then it will indicate the COMPLETION so that
781 * davinci_spi_bufs function can go ahead.
782 */
783static irqreturn_t davinci_spi_irq(s32 irq, void *data)
784{
785 struct davinci_spi *dspi = data;
786 int status;
787
788 status = davinci_spi_process_events(dspi);
789 if (unlikely(status != 0))
790 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
791
792 if ((!dspi->rcount && !dspi->wcount) || status)
793 complete(&dspi->done);
794
795 return IRQ_HANDLED;
796}
797
798static int davinci_spi_request_dma(struct davinci_spi *dspi)
799{
800 dma_cap_mask_t mask;
801 struct device *sdev = dspi->bitbang.master->dev.parent;
802 int r;
803
804 dma_cap_zero(mask);
805 dma_cap_set(DMA_SLAVE, mask);
806
807 dspi->dma_rx = dma_request_channel(mask, edma_filter_fn,
808 &dspi->dma_rx_chnum);
809 if (!dspi->dma_rx) {
810 dev_err(sdev, "request RX DMA channel failed\n");
811 r = -ENODEV;
812 goto rx_dma_failed;
813 }
814
815 dspi->dma_tx = dma_request_channel(mask, edma_filter_fn,
816 &dspi->dma_tx_chnum);
817 if (!dspi->dma_tx) {
818 dev_err(sdev, "request TX DMA channel failed\n");
819 r = -ENODEV;
820 goto tx_dma_failed;
821 }
822
823 return 0;
824
825tx_dma_failed:
826 dma_release_channel(dspi->dma_rx);
827rx_dma_failed:
828 return r;
829}
830
831#if defined(CONFIG_OF)
832
833/* OF SPI data structure */
834struct davinci_spi_of_data {
835 u8 version;
836 u8 prescaler_limit;
837};
838
839static const struct davinci_spi_of_data dm6441_spi_data = {
840 .version = SPI_VERSION_1,
841 .prescaler_limit = 2,
842};
843
844static const struct davinci_spi_of_data da830_spi_data = {
845 .version = SPI_VERSION_2,
846 .prescaler_limit = 2,
847};
848
849static const struct davinci_spi_of_data keystone_spi_data = {
850 .version = SPI_VERSION_1,
851 .prescaler_limit = 0,
852};
853
854static const struct of_device_id davinci_spi_of_match[] = {
855 {
856 .compatible = "ti,dm6441-spi",
857 .data = &dm6441_spi_data,
858 },
859 {
860 .compatible = "ti,da830-spi",
861 .data = &da830_spi_data,
862 },
863 {
864 .compatible = "ti,keystone-spi",
865 .data = &keystone_spi_data,
866 },
867 { },
868};
869MODULE_DEVICE_TABLE(of, davinci_spi_of_match);
870
871/**
872 * spi_davinci_get_pdata - Get platform data from DTS binding
873 * @pdev: ptr to platform data
874 * @dspi: ptr to driver data
875 *
876 * Parses and populates pdata in dspi from device tree bindings.
877 *
878 * NOTE: Not all platform data params are supported currently.
879 */
880static int spi_davinci_get_pdata(struct platform_device *pdev,
881 struct davinci_spi *dspi)
882{
883 struct device_node *node = pdev->dev.of_node;
884 struct davinci_spi_of_data *spi_data;
885 struct davinci_spi_platform_data *pdata;
886 unsigned int num_cs, intr_line = 0;
887 const struct of_device_id *match;
888
889 pdata = &dspi->pdata;
890
891 match = of_match_device(davinci_spi_of_match, &pdev->dev);
892 if (!match)
893 return -ENODEV;
894
895 spi_data = (struct davinci_spi_of_data *)match->data;
896
897 pdata->version = spi_data->version;
898 pdata->prescaler_limit = spi_data->prescaler_limit;
899 /*
900 * default num_cs is 1 and all chipsel are internal to the chip
901 * indicated by chip_sel being NULL or cs_gpios being NULL or
902 * set to -ENOENT. num-cs includes internal as well as gpios.
903 * indicated by chip_sel being NULL. GPIO based CS is not
904 * supported yet in DT bindings.
905 */
906 num_cs = 1;
907 of_property_read_u32(node, "num-cs", &num_cs);
908 pdata->num_chipselect = num_cs;
909 of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line);
910 pdata->intr_line = intr_line;
911 return 0;
912}
913#else
914static struct davinci_spi_platform_data
915 *spi_davinci_get_pdata(struct platform_device *pdev,
916 struct davinci_spi *dspi)
917{
918 return -ENODEV;
919}
920#endif
921
922/**
923 * davinci_spi_probe - probe function for SPI Master Controller
924 * @pdev: platform_device structure which contains plateform specific data
925 *
926 * According to Linux Device Model this function will be invoked by Linux
927 * with platform_device struct which contains the device specific info.
928 * This function will map the SPI controller's memory, register IRQ,
929 * Reset SPI controller and setting its registers to default value.
930 * It will invoke spi_bitbang_start to create work queue so that client driver
931 * can register transfer method to work queue.
932 */
933static int davinci_spi_probe(struct platform_device *pdev)
934{
935 struct spi_master *master;
936 struct davinci_spi *dspi;
937 struct davinci_spi_platform_data *pdata;
938 struct resource *r;
939 resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
940 resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
941 int ret = 0;
942 u32 spipc0;
943
944 master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
945 if (master == NULL) {
946 ret = -ENOMEM;
947 goto err;
948 }
949
950 platform_set_drvdata(pdev, master);
951
952 dspi = spi_master_get_devdata(master);
953
954 if (dev_get_platdata(&pdev->dev)) {
955 pdata = dev_get_platdata(&pdev->dev);
956 dspi->pdata = *pdata;
957 } else {
958 /* update dspi pdata with that from the DT */
959 ret = spi_davinci_get_pdata(pdev, dspi);
960 if (ret < 0)
961 goto free_master;
962 }
963
964 /* pdata in dspi is now updated and point pdata to that */
965 pdata = &dspi->pdata;
966
967 dspi->bytes_per_word = devm_kzalloc(&pdev->dev,
968 sizeof(*dspi->bytes_per_word) *
969 pdata->num_chipselect, GFP_KERNEL);
970 if (dspi->bytes_per_word == NULL) {
971 ret = -ENOMEM;
972 goto free_master;
973 }
974
975 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
976 if (r == NULL) {
977 ret = -ENOENT;
978 goto free_master;
979 }
980
981 dspi->pbase = r->start;
982
983 dspi->base = devm_ioremap_resource(&pdev->dev, r);
984 if (IS_ERR(dspi->base)) {
985 ret = PTR_ERR(dspi->base);
986 goto free_master;
987 }
988
989 ret = platform_get_irq(pdev, 0);
990 if (ret == 0)
991 ret = -EINVAL;
992 if (ret < 0)
993 goto free_master;
994 dspi->irq = ret;
995
996 ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq,
997 dummy_thread_fn, 0, dev_name(&pdev->dev), dspi);
998 if (ret)
999 goto free_master;
1000
1001 dspi->bitbang.master = master;
1002
1003 dspi->clk = devm_clk_get(&pdev->dev, NULL);
1004 if (IS_ERR(dspi->clk)) {
1005 ret = -ENODEV;
1006 goto free_master;
1007 }
1008 clk_prepare_enable(dspi->clk);
1009
1010 master->dev.of_node = pdev->dev.of_node;
1011 master->bus_num = pdev->id;
1012 master->num_chipselect = pdata->num_chipselect;
1013 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16);
1014 master->setup = davinci_spi_setup;
1015 master->cleanup = davinci_spi_cleanup;
1016
1017 dspi->bitbang.chipselect = davinci_spi_chipselect;
1018 dspi->bitbang.setup_transfer = davinci_spi_setup_transfer;
1019 dspi->prescaler_limit = pdata->prescaler_limit;
1020 dspi->version = pdata->version;
1021
1022 dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
1023 if (dspi->version == SPI_VERSION_2)
1024 dspi->bitbang.flags |= SPI_READY;
1025
1026 if (pdev->dev.of_node) {
1027 int i;
1028
1029 for (i = 0; i < pdata->num_chipselect; i++) {
1030 int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
1031 "cs-gpios", i);
1032
1033 if (cs_gpio == -EPROBE_DEFER) {
1034 ret = cs_gpio;
1035 goto free_clk;
1036 }
1037
1038 if (gpio_is_valid(cs_gpio)) {
1039 ret = devm_gpio_request(&pdev->dev, cs_gpio,
1040 dev_name(&pdev->dev));
1041 if (ret)
1042 goto free_clk;
1043 }
1044 }
1045 }
1046
1047 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1048 if (r)
1049 dma_rx_chan = r->start;
1050 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
1051 if (r)
1052 dma_tx_chan = r->start;
1053
1054 dspi->bitbang.txrx_bufs = davinci_spi_bufs;
1055 if (dma_rx_chan != SPI_NO_RESOURCE &&
1056 dma_tx_chan != SPI_NO_RESOURCE) {
1057 dspi->dma_rx_chnum = dma_rx_chan;
1058 dspi->dma_tx_chnum = dma_tx_chan;
1059
1060 ret = davinci_spi_request_dma(dspi);
1061 if (ret)
1062 goto free_clk;
1063
1064 dev_info(&pdev->dev, "DMA: supported\n");
1065 dev_info(&pdev->dev, "DMA: RX channel: %pa, TX channel: %pa, event queue: %d\n",
1066 &dma_rx_chan, &dma_tx_chan,
1067 pdata->dma_event_q);
1068 }
1069
1070 dspi->get_rx = davinci_spi_rx_buf_u8;
1071 dspi->get_tx = davinci_spi_tx_buf_u8;
1072
1073 init_completion(&dspi->done);
1074
1075 /* Reset In/OUT SPI module */
1076 iowrite32(0, dspi->base + SPIGCR0);
1077 udelay(100);
1078 iowrite32(1, dspi->base + SPIGCR0);
1079
1080 /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */
1081 spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK;
1082 iowrite32(spipc0, dspi->base + SPIPC0);
1083
1084 if (pdata->intr_line)
1085 iowrite32(SPI_INTLVL_1, dspi->base + SPILVL);
1086 else
1087 iowrite32(SPI_INTLVL_0, dspi->base + SPILVL);
1088
1089 iowrite32(CS_DEFAULT, dspi->base + SPIDEF);
1090
1091 /* master mode default */
1092 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK);
1093 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
1094 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
1095
1096 ret = spi_bitbang_start(&dspi->bitbang);
1097 if (ret)
1098 goto free_dma;
1099
1100 dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base);
1101
1102 return ret;
1103
1104free_dma:
1105 dma_release_channel(dspi->dma_rx);
1106 dma_release_channel(dspi->dma_tx);
1107free_clk:
1108 clk_disable_unprepare(dspi->clk);
1109free_master:
1110 spi_master_put(master);
1111err:
1112 return ret;
1113}
1114
1115/**
1116 * davinci_spi_remove - remove function for SPI Master Controller
1117 * @pdev: platform_device structure which contains plateform specific data
1118 *
1119 * This function will do the reverse action of davinci_spi_probe function
1120 * It will free the IRQ and SPI controller's memory region.
1121 * It will also call spi_bitbang_stop to destroy the work queue which was
1122 * created by spi_bitbang_start.
1123 */
1124static int davinci_spi_remove(struct platform_device *pdev)
1125{
1126 struct davinci_spi *dspi;
1127 struct spi_master *master;
1128
1129 master = platform_get_drvdata(pdev);
1130 dspi = spi_master_get_devdata(master);
1131
1132 spi_bitbang_stop(&dspi->bitbang);
1133
1134 clk_disable_unprepare(dspi->clk);
1135 spi_master_put(master);
1136
1137 return 0;
1138}
1139
1140static struct platform_driver davinci_spi_driver = {
1141 .driver = {
1142 .name = "spi_davinci",
1143 .of_match_table = of_match_ptr(davinci_spi_of_match),
1144 },
1145 .probe = davinci_spi_probe,
1146 .remove = davinci_spi_remove,
1147};
1148module_platform_driver(davinci_spi_driver);
1149
1150MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
1151MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2009 Texas Instruments.
3 * Copyright (C) 2010 EF Johnson Technologies
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/gpio.h>
19#include <linux/module.h>
20#include <linux/delay.h>
21#include <linux/platform_device.h>
22#include <linux/err.h>
23#include <linux/clk.h>
24#include <linux/dmaengine.h>
25#include <linux/dma-mapping.h>
26#include <linux/of.h>
27#include <linux/of_device.h>
28#include <linux/of_gpio.h>
29#include <linux/spi/spi.h>
30#include <linux/spi/spi_bitbang.h>
31#include <linux/slab.h>
32
33#include <linux/platform_data/spi-davinci.h>
34
35#define CS_DEFAULT 0xFF
36
37#define SPIFMT_PHASE_MASK BIT(16)
38#define SPIFMT_POLARITY_MASK BIT(17)
39#define SPIFMT_DISTIMER_MASK BIT(18)
40#define SPIFMT_SHIFTDIR_MASK BIT(20)
41#define SPIFMT_WAITENA_MASK BIT(21)
42#define SPIFMT_PARITYENA_MASK BIT(22)
43#define SPIFMT_ODD_PARITY_MASK BIT(23)
44#define SPIFMT_WDELAY_MASK 0x3f000000u
45#define SPIFMT_WDELAY_SHIFT 24
46#define SPIFMT_PRESCALE_SHIFT 8
47
48/* SPIPC0 */
49#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
50#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
51#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
52#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
53
54#define SPIINT_MASKALL 0x0101035F
55#define SPIINT_MASKINT 0x0000015F
56#define SPI_INTLVL_1 0x000001FF
57#define SPI_INTLVL_0 0x00000000
58
59/* SPIDAT1 (upper 16 bit defines) */
60#define SPIDAT1_CSHOLD_MASK BIT(12)
61#define SPIDAT1_WDEL BIT(10)
62
63/* SPIGCR1 */
64#define SPIGCR1_CLKMOD_MASK BIT(1)
65#define SPIGCR1_MASTER_MASK BIT(0)
66#define SPIGCR1_POWERDOWN_MASK BIT(8)
67#define SPIGCR1_LOOPBACK_MASK BIT(16)
68#define SPIGCR1_SPIENA_MASK BIT(24)
69
70/* SPIBUF */
71#define SPIBUF_TXFULL_MASK BIT(29)
72#define SPIBUF_RXEMPTY_MASK BIT(31)
73
74/* SPIDELAY */
75#define SPIDELAY_C2TDELAY_SHIFT 24
76#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
77#define SPIDELAY_T2CDELAY_SHIFT 16
78#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
79#define SPIDELAY_T2EDELAY_SHIFT 8
80#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
81#define SPIDELAY_C2EDELAY_SHIFT 0
82#define SPIDELAY_C2EDELAY_MASK 0xFF
83
84/* Error Masks */
85#define SPIFLG_DLEN_ERR_MASK BIT(0)
86#define SPIFLG_TIMEOUT_MASK BIT(1)
87#define SPIFLG_PARERR_MASK BIT(2)
88#define SPIFLG_DESYNC_MASK BIT(3)
89#define SPIFLG_BITERR_MASK BIT(4)
90#define SPIFLG_OVRRUN_MASK BIT(6)
91#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
92#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \
93 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
94 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
95 | SPIFLG_OVRRUN_MASK)
96
97#define SPIINT_DMA_REQ_EN BIT(16)
98
99/* SPI Controller registers */
100#define SPIGCR0 0x00
101#define SPIGCR1 0x04
102#define SPIINT 0x08
103#define SPILVL 0x0c
104#define SPIFLG 0x10
105#define SPIPC0 0x14
106#define SPIDAT1 0x3c
107#define SPIBUF 0x40
108#define SPIDELAY 0x48
109#define SPIDEF 0x4c
110#define SPIFMT0 0x50
111
112#define DMA_MIN_BYTES 16
113
114/* SPI Controller driver's private data. */
115struct davinci_spi {
116 struct spi_bitbang bitbang;
117 struct clk *clk;
118
119 u8 version;
120 resource_size_t pbase;
121 void __iomem *base;
122 u32 irq;
123 struct completion done;
124
125 const void *tx;
126 void *rx;
127 int rcount;
128 int wcount;
129
130 struct dma_chan *dma_rx;
131 struct dma_chan *dma_tx;
132
133 struct davinci_spi_platform_data pdata;
134
135 void (*get_rx)(u32 rx_data, struct davinci_spi *);
136 u32 (*get_tx)(struct davinci_spi *);
137
138 u8 *bytes_per_word;
139
140 u8 prescaler_limit;
141};
142
143static struct davinci_spi_config davinci_spi_default_cfg;
144
145static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi)
146{
147 if (dspi->rx) {
148 u8 *rx = dspi->rx;
149 *rx++ = (u8)data;
150 dspi->rx = rx;
151 }
152}
153
154static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi)
155{
156 if (dspi->rx) {
157 u16 *rx = dspi->rx;
158 *rx++ = (u16)data;
159 dspi->rx = rx;
160 }
161}
162
163static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi)
164{
165 u32 data = 0;
166
167 if (dspi->tx) {
168 const u8 *tx = dspi->tx;
169
170 data = *tx++;
171 dspi->tx = tx;
172 }
173 return data;
174}
175
176static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi)
177{
178 u32 data = 0;
179
180 if (dspi->tx) {
181 const u16 *tx = dspi->tx;
182
183 data = *tx++;
184 dspi->tx = tx;
185 }
186 return data;
187}
188
189static inline void set_io_bits(void __iomem *addr, u32 bits)
190{
191 u32 v = ioread32(addr);
192
193 v |= bits;
194 iowrite32(v, addr);
195}
196
197static inline void clear_io_bits(void __iomem *addr, u32 bits)
198{
199 u32 v = ioread32(addr);
200
201 v &= ~bits;
202 iowrite32(v, addr);
203}
204
205/*
206 * Interface to control the chip select signal
207 */
208static void davinci_spi_chipselect(struct spi_device *spi, int value)
209{
210 struct davinci_spi *dspi;
211 struct davinci_spi_platform_data *pdata;
212 struct davinci_spi_config *spicfg = spi->controller_data;
213 u8 chip_sel = spi->chip_select;
214 u16 spidat1 = CS_DEFAULT;
215
216 dspi = spi_master_get_devdata(spi->master);
217 pdata = &dspi->pdata;
218
219 /* program delay transfers if tx_delay is non zero */
220 if (spicfg->wdelay)
221 spidat1 |= SPIDAT1_WDEL;
222
223 /*
224 * Board specific chip select logic decides the polarity and cs
225 * line for the controller
226 */
227 if (spi->cs_gpio >= 0) {
228 if (value == BITBANG_CS_ACTIVE)
229 gpio_set_value(spi->cs_gpio, spi->mode & SPI_CS_HIGH);
230 else
231 gpio_set_value(spi->cs_gpio,
232 !(spi->mode & SPI_CS_HIGH));
233 } else {
234 if (value == BITBANG_CS_ACTIVE) {
235 spidat1 |= SPIDAT1_CSHOLD_MASK;
236 spidat1 &= ~(0x1 << chip_sel);
237 }
238 }
239
240 iowrite16(spidat1, dspi->base + SPIDAT1 + 2);
241}
242
243/**
244 * davinci_spi_get_prescale - Calculates the correct prescale value
245 * @maxspeed_hz: the maximum rate the SPI clock can run at
246 *
247 * This function calculates the prescale value that generates a clock rate
248 * less than or equal to the specified maximum.
249 *
250 * Returns: calculated prescale value for easy programming into SPI registers
251 * or negative error number if valid prescalar cannot be updated.
252 */
253static inline int davinci_spi_get_prescale(struct davinci_spi *dspi,
254 u32 max_speed_hz)
255{
256 int ret;
257
258 /* Subtract 1 to match what will be programmed into SPI register. */
259 ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1;
260
261 if (ret < dspi->prescaler_limit || ret > 255)
262 return -EINVAL;
263
264 return ret;
265}
266
267/**
268 * davinci_spi_setup_transfer - This functions will determine transfer method
269 * @spi: spi device on which data transfer to be done
270 * @t: spi transfer in which transfer info is filled
271 *
272 * This function determines data transfer method (8/16/32 bit transfer).
273 * It will also set the SPI Clock Control register according to
274 * SPI slave device freq.
275 */
276static int davinci_spi_setup_transfer(struct spi_device *spi,
277 struct spi_transfer *t)
278{
279
280 struct davinci_spi *dspi;
281 struct davinci_spi_config *spicfg;
282 u8 bits_per_word = 0;
283 u32 hz = 0, spifmt = 0;
284 int prescale;
285
286 dspi = spi_master_get_devdata(spi->master);
287 spicfg = spi->controller_data;
288 if (!spicfg)
289 spicfg = &davinci_spi_default_cfg;
290
291 if (t) {
292 bits_per_word = t->bits_per_word;
293 hz = t->speed_hz;
294 }
295
296 /* if bits_per_word is not set then set it default */
297 if (!bits_per_word)
298 bits_per_word = spi->bits_per_word;
299
300 /*
301 * Assign function pointer to appropriate transfer method
302 * 8bit, 16bit or 32bit transfer
303 */
304 if (bits_per_word <= 8) {
305 dspi->get_rx = davinci_spi_rx_buf_u8;
306 dspi->get_tx = davinci_spi_tx_buf_u8;
307 dspi->bytes_per_word[spi->chip_select] = 1;
308 } else {
309 dspi->get_rx = davinci_spi_rx_buf_u16;
310 dspi->get_tx = davinci_spi_tx_buf_u16;
311 dspi->bytes_per_word[spi->chip_select] = 2;
312 }
313
314 if (!hz)
315 hz = spi->max_speed_hz;
316
317 /* Set up SPIFMTn register, unique to this chipselect. */
318
319 prescale = davinci_spi_get_prescale(dspi, hz);
320 if (prescale < 0)
321 return prescale;
322
323 spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
324
325 if (spi->mode & SPI_LSB_FIRST)
326 spifmt |= SPIFMT_SHIFTDIR_MASK;
327
328 if (spi->mode & SPI_CPOL)
329 spifmt |= SPIFMT_POLARITY_MASK;
330
331 if (!(spi->mode & SPI_CPHA))
332 spifmt |= SPIFMT_PHASE_MASK;
333
334 /*
335 * Assume wdelay is used only on SPI peripherals that has this field
336 * in SPIFMTn register and when it's configured from board file or DT.
337 */
338 if (spicfg->wdelay)
339 spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
340 & SPIFMT_WDELAY_MASK);
341
342 /*
343 * Version 1 hardware supports two basic SPI modes:
344 * - Standard SPI mode uses 4 pins, with chipselect
345 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
346 * (distinct from SPI_3WIRE, with just one data wire;
347 * or similar variants without MOSI or without MISO)
348 *
349 * Version 2 hardware supports an optional handshaking signal,
350 * so it can support two more modes:
351 * - 5 pin SPI variant is standard SPI plus SPI_READY
352 * - 4 pin with enable is (SPI_READY | SPI_NO_CS)
353 */
354
355 if (dspi->version == SPI_VERSION_2) {
356
357 u32 delay = 0;
358
359 if (spicfg->odd_parity)
360 spifmt |= SPIFMT_ODD_PARITY_MASK;
361
362 if (spicfg->parity_enable)
363 spifmt |= SPIFMT_PARITYENA_MASK;
364
365 if (spicfg->timer_disable) {
366 spifmt |= SPIFMT_DISTIMER_MASK;
367 } else {
368 delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
369 & SPIDELAY_C2TDELAY_MASK;
370 delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
371 & SPIDELAY_T2CDELAY_MASK;
372 }
373
374 if (spi->mode & SPI_READY) {
375 spifmt |= SPIFMT_WAITENA_MASK;
376 delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
377 & SPIDELAY_T2EDELAY_MASK;
378 delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
379 & SPIDELAY_C2EDELAY_MASK;
380 }
381
382 iowrite32(delay, dspi->base + SPIDELAY);
383 }
384
385 iowrite32(spifmt, dspi->base + SPIFMT0);
386
387 return 0;
388}
389
390static int davinci_spi_of_setup(struct spi_device *spi)
391{
392 struct davinci_spi_config *spicfg = spi->controller_data;
393 struct device_node *np = spi->dev.of_node;
394 struct davinci_spi *dspi = spi_master_get_devdata(spi->master);
395 u32 prop;
396
397 if (spicfg == NULL && np) {
398 spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL);
399 if (!spicfg)
400 return -ENOMEM;
401 *spicfg = davinci_spi_default_cfg;
402 /* override with dt configured values */
403 if (!of_property_read_u32(np, "ti,spi-wdelay", &prop))
404 spicfg->wdelay = (u8)prop;
405 spi->controller_data = spicfg;
406
407 if (dspi->dma_rx && dspi->dma_tx)
408 spicfg->io_type = SPI_IO_TYPE_DMA;
409 }
410
411 return 0;
412}
413
414/**
415 * davinci_spi_setup - This functions will set default transfer method
416 * @spi: spi device on which data transfer to be done
417 *
418 * This functions sets the default transfer method.
419 */
420static int davinci_spi_setup(struct spi_device *spi)
421{
422 int retval = 0;
423 struct davinci_spi *dspi;
424 struct davinci_spi_platform_data *pdata;
425 struct spi_master *master = spi->master;
426 struct device_node *np = spi->dev.of_node;
427 bool internal_cs = true;
428
429 dspi = spi_master_get_devdata(spi->master);
430 pdata = &dspi->pdata;
431
432 if (!(spi->mode & SPI_NO_CS)) {
433 if (np && (master->cs_gpios != NULL) && (spi->cs_gpio >= 0)) {
434 retval = gpio_direction_output(
435 spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
436 internal_cs = false;
437 } else if (pdata->chip_sel &&
438 spi->chip_select < pdata->num_chipselect &&
439 pdata->chip_sel[spi->chip_select] != SPI_INTERN_CS) {
440 spi->cs_gpio = pdata->chip_sel[spi->chip_select];
441 retval = gpio_direction_output(
442 spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
443 internal_cs = false;
444 }
445
446 if (retval) {
447 dev_err(&spi->dev, "GPIO %d setup failed (%d)\n",
448 spi->cs_gpio, retval);
449 return retval;
450 }
451
452 if (internal_cs)
453 set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select);
454 }
455
456 if (spi->mode & SPI_READY)
457 set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK);
458
459 if (spi->mode & SPI_LOOP)
460 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
461 else
462 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
463
464 return davinci_spi_of_setup(spi);
465}
466
467static void davinci_spi_cleanup(struct spi_device *spi)
468{
469 struct davinci_spi_config *spicfg = spi->controller_data;
470
471 spi->controller_data = NULL;
472 if (spi->dev.of_node)
473 kfree(spicfg);
474}
475
476static bool davinci_spi_can_dma(struct spi_master *master,
477 struct spi_device *spi,
478 struct spi_transfer *xfer)
479{
480 struct davinci_spi_config *spicfg = spi->controller_data;
481 bool can_dma = false;
482
483 if (spicfg)
484 can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) &&
485 (xfer->len >= DMA_MIN_BYTES) &&
486 !is_vmalloc_addr(xfer->rx_buf) &&
487 !is_vmalloc_addr(xfer->tx_buf);
488
489 return can_dma;
490}
491
492static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status)
493{
494 struct device *sdev = dspi->bitbang.master->dev.parent;
495
496 if (int_status & SPIFLG_TIMEOUT_MASK) {
497 dev_err(sdev, "SPI Time-out Error\n");
498 return -ETIMEDOUT;
499 }
500 if (int_status & SPIFLG_DESYNC_MASK) {
501 dev_err(sdev, "SPI Desynchronization Error\n");
502 return -EIO;
503 }
504 if (int_status & SPIFLG_BITERR_MASK) {
505 dev_err(sdev, "SPI Bit error\n");
506 return -EIO;
507 }
508
509 if (dspi->version == SPI_VERSION_2) {
510 if (int_status & SPIFLG_DLEN_ERR_MASK) {
511 dev_err(sdev, "SPI Data Length Error\n");
512 return -EIO;
513 }
514 if (int_status & SPIFLG_PARERR_MASK) {
515 dev_err(sdev, "SPI Parity Error\n");
516 return -EIO;
517 }
518 if (int_status & SPIFLG_OVRRUN_MASK) {
519 dev_err(sdev, "SPI Data Overrun error\n");
520 return -EIO;
521 }
522 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
523 dev_err(sdev, "SPI Buffer Init Active\n");
524 return -EBUSY;
525 }
526 }
527
528 return 0;
529}
530
531/**
532 * davinci_spi_process_events - check for and handle any SPI controller events
533 * @dspi: the controller data
534 *
535 * This function will check the SPIFLG register and handle any events that are
536 * detected there
537 */
538static int davinci_spi_process_events(struct davinci_spi *dspi)
539{
540 u32 buf, status, errors = 0, spidat1;
541
542 buf = ioread32(dspi->base + SPIBUF);
543
544 if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) {
545 dspi->get_rx(buf & 0xFFFF, dspi);
546 dspi->rcount--;
547 }
548
549 status = ioread32(dspi->base + SPIFLG);
550
551 if (unlikely(status & SPIFLG_ERROR_MASK)) {
552 errors = status & SPIFLG_ERROR_MASK;
553 goto out;
554 }
555
556 if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
557 spidat1 = ioread32(dspi->base + SPIDAT1);
558 dspi->wcount--;
559 spidat1 &= ~0xFFFF;
560 spidat1 |= 0xFFFF & dspi->get_tx(dspi);
561 iowrite32(spidat1, dspi->base + SPIDAT1);
562 }
563
564out:
565 return errors;
566}
567
568static void davinci_spi_dma_rx_callback(void *data)
569{
570 struct davinci_spi *dspi = (struct davinci_spi *)data;
571
572 dspi->rcount = 0;
573
574 if (!dspi->wcount && !dspi->rcount)
575 complete(&dspi->done);
576}
577
578static void davinci_spi_dma_tx_callback(void *data)
579{
580 struct davinci_spi *dspi = (struct davinci_spi *)data;
581
582 dspi->wcount = 0;
583
584 if (!dspi->wcount && !dspi->rcount)
585 complete(&dspi->done);
586}
587
588/**
589 * davinci_spi_bufs - functions which will handle transfer data
590 * @spi: spi device on which data transfer to be done
591 * @t: spi transfer in which transfer info is filled
592 *
593 * This function will put data to be transferred into data register
594 * of SPI controller and then wait until the completion will be marked
595 * by the IRQ Handler.
596 */
597static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
598{
599 struct davinci_spi *dspi;
600 int data_type, ret = -ENOMEM;
601 u32 tx_data, spidat1;
602 u32 errors = 0;
603 struct davinci_spi_config *spicfg;
604 struct davinci_spi_platform_data *pdata;
605 unsigned uninitialized_var(rx_buf_count);
606
607 dspi = spi_master_get_devdata(spi->master);
608 pdata = &dspi->pdata;
609 spicfg = (struct davinci_spi_config *)spi->controller_data;
610 if (!spicfg)
611 spicfg = &davinci_spi_default_cfg;
612
613 /* convert len to words based on bits_per_word */
614 data_type = dspi->bytes_per_word[spi->chip_select];
615
616 dspi->tx = t->tx_buf;
617 dspi->rx = t->rx_buf;
618 dspi->wcount = t->len / data_type;
619 dspi->rcount = dspi->wcount;
620
621 spidat1 = ioread32(dspi->base + SPIDAT1);
622
623 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
624 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
625
626 reinit_completion(&dspi->done);
627
628 if (!davinci_spi_can_dma(spi->master, spi, t)) {
629 if (spicfg->io_type != SPI_IO_TYPE_POLL)
630 set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
631 /* start the transfer */
632 dspi->wcount--;
633 tx_data = dspi->get_tx(dspi);
634 spidat1 &= 0xFFFF0000;
635 spidat1 |= tx_data & 0xFFFF;
636 iowrite32(spidat1, dspi->base + SPIDAT1);
637 } else {
638 struct dma_slave_config dma_rx_conf = {
639 .direction = DMA_DEV_TO_MEM,
640 .src_addr = (unsigned long)dspi->pbase + SPIBUF,
641 .src_addr_width = data_type,
642 .src_maxburst = 1,
643 };
644 struct dma_slave_config dma_tx_conf = {
645 .direction = DMA_MEM_TO_DEV,
646 .dst_addr = (unsigned long)dspi->pbase + SPIDAT1,
647 .dst_addr_width = data_type,
648 .dst_maxburst = 1,
649 };
650 struct dma_async_tx_descriptor *rxdesc;
651 struct dma_async_tx_descriptor *txdesc;
652
653 dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf);
654 dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf);
655
656 rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx,
657 t->rx_sg.sgl, t->rx_sg.nents, DMA_DEV_TO_MEM,
658 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
659 if (!rxdesc)
660 goto err_desc;
661
662 if (!t->tx_buf) {
663 /* To avoid errors when doing rx-only transfers with
664 * many SG entries (> 20), use the rx buffer as the
665 * dummy tx buffer so that dma reloads are done at the
666 * same time for rx and tx.
667 */
668 t->tx_sg.sgl = t->rx_sg.sgl;
669 t->tx_sg.nents = t->rx_sg.nents;
670 }
671
672 txdesc = dmaengine_prep_slave_sg(dspi->dma_tx,
673 t->tx_sg.sgl, t->tx_sg.nents, DMA_MEM_TO_DEV,
674 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
675 if (!txdesc)
676 goto err_desc;
677
678 rxdesc->callback = davinci_spi_dma_rx_callback;
679 rxdesc->callback_param = (void *)dspi;
680 txdesc->callback = davinci_spi_dma_tx_callback;
681 txdesc->callback_param = (void *)dspi;
682
683 if (pdata->cshold_bug)
684 iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2);
685
686 dmaengine_submit(rxdesc);
687 dmaengine_submit(txdesc);
688
689 dma_async_issue_pending(dspi->dma_rx);
690 dma_async_issue_pending(dspi->dma_tx);
691
692 set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
693 }
694
695 /* Wait for the transfer to complete */
696 if (spicfg->io_type != SPI_IO_TYPE_POLL) {
697 if (wait_for_completion_timeout(&dspi->done, HZ) == 0)
698 errors = SPIFLG_TIMEOUT_MASK;
699 } else {
700 while (dspi->rcount > 0 || dspi->wcount > 0) {
701 errors = davinci_spi_process_events(dspi);
702 if (errors)
703 break;
704 cpu_relax();
705 }
706 }
707
708 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL);
709 if (davinci_spi_can_dma(spi->master, spi, t))
710 clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
711
712 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
713 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
714
715 /*
716 * Check for bit error, desync error,parity error,timeout error and
717 * receive overflow errors
718 */
719 if (errors) {
720 ret = davinci_spi_check_error(dspi, errors);
721 WARN(!ret, "%s: error reported but no error found!\n",
722 dev_name(&spi->dev));
723 return ret;
724 }
725
726 if (dspi->rcount != 0 || dspi->wcount != 0) {
727 dev_err(&spi->dev, "SPI data transfer error\n");
728 return -EIO;
729 }
730
731 return t->len;
732
733err_desc:
734 return ret;
735}
736
737/**
738 * dummy_thread_fn - dummy thread function
739 * @irq: IRQ number for this SPI Master
740 * @context_data: structure for SPI Master controller davinci_spi
741 *
742 * This is to satisfy the request_threaded_irq() API so that the irq
743 * handler is called in interrupt context.
744 */
745static irqreturn_t dummy_thread_fn(s32 irq, void *data)
746{
747 return IRQ_HANDLED;
748}
749
750/**
751 * davinci_spi_irq - Interrupt handler for SPI Master Controller
752 * @irq: IRQ number for this SPI Master
753 * @context_data: structure for SPI Master controller davinci_spi
754 *
755 * ISR will determine that interrupt arrives either for READ or WRITE command.
756 * According to command it will do the appropriate action. It will check
757 * transfer length and if it is not zero then dispatch transfer command again.
758 * If transfer length is zero then it will indicate the COMPLETION so that
759 * davinci_spi_bufs function can go ahead.
760 */
761static irqreturn_t davinci_spi_irq(s32 irq, void *data)
762{
763 struct davinci_spi *dspi = data;
764 int status;
765
766 status = davinci_spi_process_events(dspi);
767 if (unlikely(status != 0))
768 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
769
770 if ((!dspi->rcount && !dspi->wcount) || status)
771 complete(&dspi->done);
772
773 return IRQ_HANDLED;
774}
775
776static int davinci_spi_request_dma(struct davinci_spi *dspi)
777{
778 struct device *sdev = dspi->bitbang.master->dev.parent;
779
780 dspi->dma_rx = dma_request_chan(sdev, "rx");
781 if (IS_ERR(dspi->dma_rx))
782 return PTR_ERR(dspi->dma_rx);
783
784 dspi->dma_tx = dma_request_chan(sdev, "tx");
785 if (IS_ERR(dspi->dma_tx)) {
786 dma_release_channel(dspi->dma_rx);
787 return PTR_ERR(dspi->dma_tx);
788 }
789
790 return 0;
791}
792
793#if defined(CONFIG_OF)
794
795/* OF SPI data structure */
796struct davinci_spi_of_data {
797 u8 version;
798 u8 prescaler_limit;
799};
800
801static const struct davinci_spi_of_data dm6441_spi_data = {
802 .version = SPI_VERSION_1,
803 .prescaler_limit = 2,
804};
805
806static const struct davinci_spi_of_data da830_spi_data = {
807 .version = SPI_VERSION_2,
808 .prescaler_limit = 2,
809};
810
811static const struct davinci_spi_of_data keystone_spi_data = {
812 .version = SPI_VERSION_1,
813 .prescaler_limit = 0,
814};
815
816static const struct of_device_id davinci_spi_of_match[] = {
817 {
818 .compatible = "ti,dm6441-spi",
819 .data = &dm6441_spi_data,
820 },
821 {
822 .compatible = "ti,da830-spi",
823 .data = &da830_spi_data,
824 },
825 {
826 .compatible = "ti,keystone-spi",
827 .data = &keystone_spi_data,
828 },
829 { },
830};
831MODULE_DEVICE_TABLE(of, davinci_spi_of_match);
832
833/**
834 * spi_davinci_get_pdata - Get platform data from DTS binding
835 * @pdev: ptr to platform data
836 * @dspi: ptr to driver data
837 *
838 * Parses and populates pdata in dspi from device tree bindings.
839 *
840 * NOTE: Not all platform data params are supported currently.
841 */
842static int spi_davinci_get_pdata(struct platform_device *pdev,
843 struct davinci_spi *dspi)
844{
845 struct device_node *node = pdev->dev.of_node;
846 struct davinci_spi_of_data *spi_data;
847 struct davinci_spi_platform_data *pdata;
848 unsigned int num_cs, intr_line = 0;
849 const struct of_device_id *match;
850
851 pdata = &dspi->pdata;
852
853 match = of_match_device(davinci_spi_of_match, &pdev->dev);
854 if (!match)
855 return -ENODEV;
856
857 spi_data = (struct davinci_spi_of_data *)match->data;
858
859 pdata->version = spi_data->version;
860 pdata->prescaler_limit = spi_data->prescaler_limit;
861 /*
862 * default num_cs is 1 and all chipsel are internal to the chip
863 * indicated by chip_sel being NULL or cs_gpios being NULL or
864 * set to -ENOENT. num-cs includes internal as well as gpios.
865 * indicated by chip_sel being NULL. GPIO based CS is not
866 * supported yet in DT bindings.
867 */
868 num_cs = 1;
869 of_property_read_u32(node, "num-cs", &num_cs);
870 pdata->num_chipselect = num_cs;
871 of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line);
872 pdata->intr_line = intr_line;
873 return 0;
874}
875#else
876static int spi_davinci_get_pdata(struct platform_device *pdev,
877 struct davinci_spi *dspi)
878{
879 return -ENODEV;
880}
881#endif
882
883/**
884 * davinci_spi_probe - probe function for SPI Master Controller
885 * @pdev: platform_device structure which contains plateform specific data
886 *
887 * According to Linux Device Model this function will be invoked by Linux
888 * with platform_device struct which contains the device specific info.
889 * This function will map the SPI controller's memory, register IRQ,
890 * Reset SPI controller and setting its registers to default value.
891 * It will invoke spi_bitbang_start to create work queue so that client driver
892 * can register transfer method to work queue.
893 */
894static int davinci_spi_probe(struct platform_device *pdev)
895{
896 struct spi_master *master;
897 struct davinci_spi *dspi;
898 struct davinci_spi_platform_data *pdata;
899 struct resource *r;
900 int ret = 0;
901 u32 spipc0;
902
903 master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
904 if (master == NULL) {
905 ret = -ENOMEM;
906 goto err;
907 }
908
909 platform_set_drvdata(pdev, master);
910
911 dspi = spi_master_get_devdata(master);
912
913 if (dev_get_platdata(&pdev->dev)) {
914 pdata = dev_get_platdata(&pdev->dev);
915 dspi->pdata = *pdata;
916 } else {
917 /* update dspi pdata with that from the DT */
918 ret = spi_davinci_get_pdata(pdev, dspi);
919 if (ret < 0)
920 goto free_master;
921 }
922
923 /* pdata in dspi is now updated and point pdata to that */
924 pdata = &dspi->pdata;
925
926 dspi->bytes_per_word = devm_kzalloc(&pdev->dev,
927 sizeof(*dspi->bytes_per_word) *
928 pdata->num_chipselect, GFP_KERNEL);
929 if (dspi->bytes_per_word == NULL) {
930 ret = -ENOMEM;
931 goto free_master;
932 }
933
934 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
935 if (r == NULL) {
936 ret = -ENOENT;
937 goto free_master;
938 }
939
940 dspi->pbase = r->start;
941
942 dspi->base = devm_ioremap_resource(&pdev->dev, r);
943 if (IS_ERR(dspi->base)) {
944 ret = PTR_ERR(dspi->base);
945 goto free_master;
946 }
947
948 init_completion(&dspi->done);
949
950 ret = platform_get_irq(pdev, 0);
951 if (ret == 0)
952 ret = -EINVAL;
953 if (ret < 0)
954 goto free_master;
955 dspi->irq = ret;
956
957 ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq,
958 dummy_thread_fn, 0, dev_name(&pdev->dev), dspi);
959 if (ret)
960 goto free_master;
961
962 dspi->bitbang.master = master;
963
964 dspi->clk = devm_clk_get(&pdev->dev, NULL);
965 if (IS_ERR(dspi->clk)) {
966 ret = -ENODEV;
967 goto free_master;
968 }
969 ret = clk_prepare_enable(dspi->clk);
970 if (ret)
971 goto free_master;
972
973 master->dev.of_node = pdev->dev.of_node;
974 master->bus_num = pdev->id;
975 master->num_chipselect = pdata->num_chipselect;
976 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16);
977 master->flags = SPI_MASTER_MUST_RX;
978 master->setup = davinci_spi_setup;
979 master->cleanup = davinci_spi_cleanup;
980 master->can_dma = davinci_spi_can_dma;
981
982 dspi->bitbang.chipselect = davinci_spi_chipselect;
983 dspi->bitbang.setup_transfer = davinci_spi_setup_transfer;
984 dspi->prescaler_limit = pdata->prescaler_limit;
985 dspi->version = pdata->version;
986
987 dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
988 if (dspi->version == SPI_VERSION_2)
989 dspi->bitbang.flags |= SPI_READY;
990
991 if (pdev->dev.of_node) {
992 int i;
993
994 for (i = 0; i < pdata->num_chipselect; i++) {
995 int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
996 "cs-gpios", i);
997
998 if (cs_gpio == -EPROBE_DEFER) {
999 ret = cs_gpio;
1000 goto free_clk;
1001 }
1002
1003 if (gpio_is_valid(cs_gpio)) {
1004 ret = devm_gpio_request(&pdev->dev, cs_gpio,
1005 dev_name(&pdev->dev));
1006 if (ret)
1007 goto free_clk;
1008 }
1009 }
1010 }
1011
1012 dspi->bitbang.txrx_bufs = davinci_spi_bufs;
1013
1014 ret = davinci_spi_request_dma(dspi);
1015 if (ret == -EPROBE_DEFER) {
1016 goto free_clk;
1017 } else if (ret) {
1018 dev_info(&pdev->dev, "DMA is not supported (%d)\n", ret);
1019 dspi->dma_rx = NULL;
1020 dspi->dma_tx = NULL;
1021 }
1022
1023 dspi->get_rx = davinci_spi_rx_buf_u8;
1024 dspi->get_tx = davinci_spi_tx_buf_u8;
1025
1026 /* Reset In/OUT SPI module */
1027 iowrite32(0, dspi->base + SPIGCR0);
1028 udelay(100);
1029 iowrite32(1, dspi->base + SPIGCR0);
1030
1031 /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */
1032 spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK;
1033 iowrite32(spipc0, dspi->base + SPIPC0);
1034
1035 if (pdata->intr_line)
1036 iowrite32(SPI_INTLVL_1, dspi->base + SPILVL);
1037 else
1038 iowrite32(SPI_INTLVL_0, dspi->base + SPILVL);
1039
1040 iowrite32(CS_DEFAULT, dspi->base + SPIDEF);
1041
1042 /* master mode default */
1043 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK);
1044 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
1045 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
1046
1047 ret = spi_bitbang_start(&dspi->bitbang);
1048 if (ret)
1049 goto free_dma;
1050
1051 dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base);
1052
1053 return ret;
1054
1055free_dma:
1056 if (dspi->dma_rx) {
1057 dma_release_channel(dspi->dma_rx);
1058 dma_release_channel(dspi->dma_tx);
1059 }
1060free_clk:
1061 clk_disable_unprepare(dspi->clk);
1062free_master:
1063 spi_master_put(master);
1064err:
1065 return ret;
1066}
1067
1068/**
1069 * davinci_spi_remove - remove function for SPI Master Controller
1070 * @pdev: platform_device structure which contains plateform specific data
1071 *
1072 * This function will do the reverse action of davinci_spi_probe function
1073 * It will free the IRQ and SPI controller's memory region.
1074 * It will also call spi_bitbang_stop to destroy the work queue which was
1075 * created by spi_bitbang_start.
1076 */
1077static int davinci_spi_remove(struct platform_device *pdev)
1078{
1079 struct davinci_spi *dspi;
1080 struct spi_master *master;
1081
1082 master = platform_get_drvdata(pdev);
1083 dspi = spi_master_get_devdata(master);
1084
1085 spi_bitbang_stop(&dspi->bitbang);
1086
1087 clk_disable_unprepare(dspi->clk);
1088 spi_master_put(master);
1089
1090 if (dspi->dma_rx) {
1091 dma_release_channel(dspi->dma_rx);
1092 dma_release_channel(dspi->dma_tx);
1093 }
1094
1095 return 0;
1096}
1097
1098static struct platform_driver davinci_spi_driver = {
1099 .driver = {
1100 .name = "spi_davinci",
1101 .of_match_table = of_match_ptr(davinci_spi_of_match),
1102 },
1103 .probe = davinci_spi_probe,
1104 .remove = davinci_spi_remove,
1105};
1106module_platform_driver(davinci_spi_driver);
1107
1108MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
1109MODULE_LICENSE("GPL");