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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2009 Texas Instruments.
4 * Copyright (C) 2010 EF Johnson Technologies
5 */
6
7#include <linux/interrupt.h>
8#include <linux/io.h>
9#include <linux/gpio/consumer.h>
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/platform_device.h>
13#include <linux/err.h>
14#include <linux/clk.h>
15#include <linux/dmaengine.h>
16#include <linux/dma-mapping.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19#include <linux/spi/spi.h>
20#include <linux/spi/spi_bitbang.h>
21#include <linux/slab.h>
22
23#include <linux/platform_data/spi-davinci.h>
24
25#define CS_DEFAULT 0xFF
26
27#define SPIFMT_PHASE_MASK BIT(16)
28#define SPIFMT_POLARITY_MASK BIT(17)
29#define SPIFMT_DISTIMER_MASK BIT(18)
30#define SPIFMT_SHIFTDIR_MASK BIT(20)
31#define SPIFMT_WAITENA_MASK BIT(21)
32#define SPIFMT_PARITYENA_MASK BIT(22)
33#define SPIFMT_ODD_PARITY_MASK BIT(23)
34#define SPIFMT_WDELAY_MASK 0x3f000000u
35#define SPIFMT_WDELAY_SHIFT 24
36#define SPIFMT_PRESCALE_SHIFT 8
37
38/* SPIPC0 */
39#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
40#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
41#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
42#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
43
44#define SPIINT_MASKALL 0x0101035F
45#define SPIINT_MASKINT 0x0000015F
46#define SPI_INTLVL_1 0x000001FF
47#define SPI_INTLVL_0 0x00000000
48
49/* SPIDAT1 (upper 16 bit defines) */
50#define SPIDAT1_CSHOLD_MASK BIT(12)
51#define SPIDAT1_WDEL BIT(10)
52
53/* SPIGCR1 */
54#define SPIGCR1_CLKMOD_MASK BIT(1)
55#define SPIGCR1_MASTER_MASK BIT(0)
56#define SPIGCR1_POWERDOWN_MASK BIT(8)
57#define SPIGCR1_LOOPBACK_MASK BIT(16)
58#define SPIGCR1_SPIENA_MASK BIT(24)
59
60/* SPIBUF */
61#define SPIBUF_TXFULL_MASK BIT(29)
62#define SPIBUF_RXEMPTY_MASK BIT(31)
63
64/* SPIDELAY */
65#define SPIDELAY_C2TDELAY_SHIFT 24
66#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
67#define SPIDELAY_T2CDELAY_SHIFT 16
68#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
69#define SPIDELAY_T2EDELAY_SHIFT 8
70#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
71#define SPIDELAY_C2EDELAY_SHIFT 0
72#define SPIDELAY_C2EDELAY_MASK 0xFF
73
74/* Error Masks */
75#define SPIFLG_DLEN_ERR_MASK BIT(0)
76#define SPIFLG_TIMEOUT_MASK BIT(1)
77#define SPIFLG_PARERR_MASK BIT(2)
78#define SPIFLG_DESYNC_MASK BIT(3)
79#define SPIFLG_BITERR_MASK BIT(4)
80#define SPIFLG_OVRRUN_MASK BIT(6)
81#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
82#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \
83 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
84 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
85 | SPIFLG_OVRRUN_MASK)
86
87#define SPIINT_DMA_REQ_EN BIT(16)
88
89/* SPI Controller registers */
90#define SPIGCR0 0x00
91#define SPIGCR1 0x04
92#define SPIINT 0x08
93#define SPILVL 0x0c
94#define SPIFLG 0x10
95#define SPIPC0 0x14
96#define SPIDAT1 0x3c
97#define SPIBUF 0x40
98#define SPIDELAY 0x48
99#define SPIDEF 0x4c
100#define SPIFMT0 0x50
101
102#define DMA_MIN_BYTES 16
103
104/* SPI Controller driver's private data. */
105struct davinci_spi {
106 struct spi_bitbang bitbang;
107 struct clk *clk;
108
109 u8 version;
110 resource_size_t pbase;
111 void __iomem *base;
112 u32 irq;
113 struct completion done;
114
115 const void *tx;
116 void *rx;
117 int rcount;
118 int wcount;
119
120 struct dma_chan *dma_rx;
121 struct dma_chan *dma_tx;
122
123 struct davinci_spi_platform_data pdata;
124
125 void (*get_rx)(u32 rx_data, struct davinci_spi *);
126 u32 (*get_tx)(struct davinci_spi *);
127
128 u8 *bytes_per_word;
129
130 u8 prescaler_limit;
131};
132
133static struct davinci_spi_config davinci_spi_default_cfg;
134
135static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi)
136{
137 if (dspi->rx) {
138 u8 *rx = dspi->rx;
139 *rx++ = (u8)data;
140 dspi->rx = rx;
141 }
142}
143
144static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi)
145{
146 if (dspi->rx) {
147 u16 *rx = dspi->rx;
148 *rx++ = (u16)data;
149 dspi->rx = rx;
150 }
151}
152
153static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi)
154{
155 u32 data = 0;
156
157 if (dspi->tx) {
158 const u8 *tx = dspi->tx;
159
160 data = *tx++;
161 dspi->tx = tx;
162 }
163 return data;
164}
165
166static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi)
167{
168 u32 data = 0;
169
170 if (dspi->tx) {
171 const u16 *tx = dspi->tx;
172
173 data = *tx++;
174 dspi->tx = tx;
175 }
176 return data;
177}
178
179static inline void set_io_bits(void __iomem *addr, u32 bits)
180{
181 u32 v = ioread32(addr);
182
183 v |= bits;
184 iowrite32(v, addr);
185}
186
187static inline void clear_io_bits(void __iomem *addr, u32 bits)
188{
189 u32 v = ioread32(addr);
190
191 v &= ~bits;
192 iowrite32(v, addr);
193}
194
195/*
196 * Interface to control the chip select signal
197 */
198static void davinci_spi_chipselect(struct spi_device *spi, int value)
199{
200 struct davinci_spi *dspi;
201 struct davinci_spi_config *spicfg = spi->controller_data;
202 u8 chip_sel = spi->chip_select;
203 u16 spidat1 = CS_DEFAULT;
204
205 dspi = spi_master_get_devdata(spi->master);
206
207 /* program delay transfers if tx_delay is non zero */
208 if (spicfg && spicfg->wdelay)
209 spidat1 |= SPIDAT1_WDEL;
210
211 /*
212 * Board specific chip select logic decides the polarity and cs
213 * line for the controller
214 */
215 if (spi->cs_gpiod) {
216 if (value == BITBANG_CS_ACTIVE)
217 gpiod_set_value(spi->cs_gpiod, 1);
218 else
219 gpiod_set_value(spi->cs_gpiod, 0);
220 } else {
221 if (value == BITBANG_CS_ACTIVE) {
222 if (!(spi->mode & SPI_CS_WORD))
223 spidat1 |= SPIDAT1_CSHOLD_MASK;
224 spidat1 &= ~(0x1 << chip_sel);
225 }
226 }
227
228 iowrite16(spidat1, dspi->base + SPIDAT1 + 2);
229}
230
231/**
232 * davinci_spi_get_prescale - Calculates the correct prescale value
233 * @dspi: the controller data
234 * @max_speed_hz: the maximum rate the SPI clock can run at
235 *
236 * This function calculates the prescale value that generates a clock rate
237 * less than or equal to the specified maximum.
238 *
239 * Returns: calculated prescale value for easy programming into SPI registers
240 * or negative error number if valid prescalar cannot be updated.
241 */
242static inline int davinci_spi_get_prescale(struct davinci_spi *dspi,
243 u32 max_speed_hz)
244{
245 int ret;
246
247 /* Subtract 1 to match what will be programmed into SPI register. */
248 ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1;
249
250 if (ret < dspi->prescaler_limit || ret > 255)
251 return -EINVAL;
252
253 return ret;
254}
255
256/**
257 * davinci_spi_setup_transfer - This functions will determine transfer method
258 * @spi: spi device on which data transfer to be done
259 * @t: spi transfer in which transfer info is filled
260 *
261 * This function determines data transfer method (8/16/32 bit transfer).
262 * It will also set the SPI Clock Control register according to
263 * SPI slave device freq.
264 */
265static int davinci_spi_setup_transfer(struct spi_device *spi,
266 struct spi_transfer *t)
267{
268
269 struct davinci_spi *dspi;
270 struct davinci_spi_config *spicfg;
271 u8 bits_per_word = 0;
272 u32 hz = 0, spifmt = 0;
273 int prescale;
274
275 dspi = spi_master_get_devdata(spi->master);
276 spicfg = spi->controller_data;
277 if (!spicfg)
278 spicfg = &davinci_spi_default_cfg;
279
280 if (t) {
281 bits_per_word = t->bits_per_word;
282 hz = t->speed_hz;
283 }
284
285 /* if bits_per_word is not set then set it default */
286 if (!bits_per_word)
287 bits_per_word = spi->bits_per_word;
288
289 /*
290 * Assign function pointer to appropriate transfer method
291 * 8bit, 16bit or 32bit transfer
292 */
293 if (bits_per_word <= 8) {
294 dspi->get_rx = davinci_spi_rx_buf_u8;
295 dspi->get_tx = davinci_spi_tx_buf_u8;
296 dspi->bytes_per_word[spi->chip_select] = 1;
297 } else {
298 dspi->get_rx = davinci_spi_rx_buf_u16;
299 dspi->get_tx = davinci_spi_tx_buf_u16;
300 dspi->bytes_per_word[spi->chip_select] = 2;
301 }
302
303 if (!hz)
304 hz = spi->max_speed_hz;
305
306 /* Set up SPIFMTn register, unique to this chipselect. */
307
308 prescale = davinci_spi_get_prescale(dspi, hz);
309 if (prescale < 0)
310 return prescale;
311
312 spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
313
314 if (spi->mode & SPI_LSB_FIRST)
315 spifmt |= SPIFMT_SHIFTDIR_MASK;
316
317 if (spi->mode & SPI_CPOL)
318 spifmt |= SPIFMT_POLARITY_MASK;
319
320 if (!(spi->mode & SPI_CPHA))
321 spifmt |= SPIFMT_PHASE_MASK;
322
323 /*
324 * Assume wdelay is used only on SPI peripherals that has this field
325 * in SPIFMTn register and when it's configured from board file or DT.
326 */
327 if (spicfg->wdelay)
328 spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
329 & SPIFMT_WDELAY_MASK);
330
331 /*
332 * Version 1 hardware supports two basic SPI modes:
333 * - Standard SPI mode uses 4 pins, with chipselect
334 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
335 * (distinct from SPI_3WIRE, with just one data wire;
336 * or similar variants without MOSI or without MISO)
337 *
338 * Version 2 hardware supports an optional handshaking signal,
339 * so it can support two more modes:
340 * - 5 pin SPI variant is standard SPI plus SPI_READY
341 * - 4 pin with enable is (SPI_READY | SPI_NO_CS)
342 */
343
344 if (dspi->version == SPI_VERSION_2) {
345
346 u32 delay = 0;
347
348 if (spicfg->odd_parity)
349 spifmt |= SPIFMT_ODD_PARITY_MASK;
350
351 if (spicfg->parity_enable)
352 spifmt |= SPIFMT_PARITYENA_MASK;
353
354 if (spicfg->timer_disable) {
355 spifmt |= SPIFMT_DISTIMER_MASK;
356 } else {
357 delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
358 & SPIDELAY_C2TDELAY_MASK;
359 delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
360 & SPIDELAY_T2CDELAY_MASK;
361 }
362
363 if (spi->mode & SPI_READY) {
364 spifmt |= SPIFMT_WAITENA_MASK;
365 delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
366 & SPIDELAY_T2EDELAY_MASK;
367 delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
368 & SPIDELAY_C2EDELAY_MASK;
369 }
370
371 iowrite32(delay, dspi->base + SPIDELAY);
372 }
373
374 iowrite32(spifmt, dspi->base + SPIFMT0);
375
376 return 0;
377}
378
379static int davinci_spi_of_setup(struct spi_device *spi)
380{
381 struct davinci_spi_config *spicfg = spi->controller_data;
382 struct device_node *np = spi->dev.of_node;
383 struct davinci_spi *dspi = spi_master_get_devdata(spi->master);
384 u32 prop;
385
386 if (spicfg == NULL && np) {
387 spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL);
388 if (!spicfg)
389 return -ENOMEM;
390 *spicfg = davinci_spi_default_cfg;
391 /* override with dt configured values */
392 if (!of_property_read_u32(np, "ti,spi-wdelay", &prop))
393 spicfg->wdelay = (u8)prop;
394 spi->controller_data = spicfg;
395
396 if (dspi->dma_rx && dspi->dma_tx)
397 spicfg->io_type = SPI_IO_TYPE_DMA;
398 }
399
400 return 0;
401}
402
403/**
404 * davinci_spi_setup - This functions will set default transfer method
405 * @spi: spi device on which data transfer to be done
406 *
407 * This functions sets the default transfer method.
408 */
409static int davinci_spi_setup(struct spi_device *spi)
410{
411 struct davinci_spi *dspi;
412 struct device_node *np = spi->dev.of_node;
413 bool internal_cs = true;
414
415 dspi = spi_master_get_devdata(spi->master);
416
417 if (!(spi->mode & SPI_NO_CS)) {
418 if (np && spi->cs_gpiod)
419 internal_cs = false;
420
421 if (internal_cs)
422 set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select);
423 }
424
425 if (spi->mode & SPI_READY)
426 set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK);
427
428 if (spi->mode & SPI_LOOP)
429 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
430 else
431 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
432
433 return davinci_spi_of_setup(spi);
434}
435
436static void davinci_spi_cleanup(struct spi_device *spi)
437{
438 struct davinci_spi_config *spicfg = spi->controller_data;
439
440 spi->controller_data = NULL;
441 if (spi->dev.of_node)
442 kfree(spicfg);
443}
444
445static bool davinci_spi_can_dma(struct spi_master *master,
446 struct spi_device *spi,
447 struct spi_transfer *xfer)
448{
449 struct davinci_spi_config *spicfg = spi->controller_data;
450 bool can_dma = false;
451
452 if (spicfg)
453 can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) &&
454 (xfer->len >= DMA_MIN_BYTES) &&
455 !is_vmalloc_addr(xfer->rx_buf) &&
456 !is_vmalloc_addr(xfer->tx_buf);
457
458 return can_dma;
459}
460
461static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status)
462{
463 struct device *sdev = dspi->bitbang.master->dev.parent;
464
465 if (int_status & SPIFLG_TIMEOUT_MASK) {
466 dev_err(sdev, "SPI Time-out Error\n");
467 return -ETIMEDOUT;
468 }
469 if (int_status & SPIFLG_DESYNC_MASK) {
470 dev_err(sdev, "SPI Desynchronization Error\n");
471 return -EIO;
472 }
473 if (int_status & SPIFLG_BITERR_MASK) {
474 dev_err(sdev, "SPI Bit error\n");
475 return -EIO;
476 }
477
478 if (dspi->version == SPI_VERSION_2) {
479 if (int_status & SPIFLG_DLEN_ERR_MASK) {
480 dev_err(sdev, "SPI Data Length Error\n");
481 return -EIO;
482 }
483 if (int_status & SPIFLG_PARERR_MASK) {
484 dev_err(sdev, "SPI Parity Error\n");
485 return -EIO;
486 }
487 if (int_status & SPIFLG_OVRRUN_MASK) {
488 dev_err(sdev, "SPI Data Overrun error\n");
489 return -EIO;
490 }
491 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
492 dev_err(sdev, "SPI Buffer Init Active\n");
493 return -EBUSY;
494 }
495 }
496
497 return 0;
498}
499
500/**
501 * davinci_spi_process_events - check for and handle any SPI controller events
502 * @dspi: the controller data
503 *
504 * This function will check the SPIFLG register and handle any events that are
505 * detected there
506 */
507static int davinci_spi_process_events(struct davinci_spi *dspi)
508{
509 u32 buf, status, errors = 0, spidat1;
510
511 buf = ioread32(dspi->base + SPIBUF);
512
513 if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) {
514 dspi->get_rx(buf & 0xFFFF, dspi);
515 dspi->rcount--;
516 }
517
518 status = ioread32(dspi->base + SPIFLG);
519
520 if (unlikely(status & SPIFLG_ERROR_MASK)) {
521 errors = status & SPIFLG_ERROR_MASK;
522 goto out;
523 }
524
525 if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
526 spidat1 = ioread32(dspi->base + SPIDAT1);
527 dspi->wcount--;
528 spidat1 &= ~0xFFFF;
529 spidat1 |= 0xFFFF & dspi->get_tx(dspi);
530 iowrite32(spidat1, dspi->base + SPIDAT1);
531 }
532
533out:
534 return errors;
535}
536
537static void davinci_spi_dma_rx_callback(void *data)
538{
539 struct davinci_spi *dspi = (struct davinci_spi *)data;
540
541 dspi->rcount = 0;
542
543 if (!dspi->wcount && !dspi->rcount)
544 complete(&dspi->done);
545}
546
547static void davinci_spi_dma_tx_callback(void *data)
548{
549 struct davinci_spi *dspi = (struct davinci_spi *)data;
550
551 dspi->wcount = 0;
552
553 if (!dspi->wcount && !dspi->rcount)
554 complete(&dspi->done);
555}
556
557/**
558 * davinci_spi_bufs - functions which will handle transfer data
559 * @spi: spi device on which data transfer to be done
560 * @t: spi transfer in which transfer info is filled
561 *
562 * This function will put data to be transferred into data register
563 * of SPI controller and then wait until the completion will be marked
564 * by the IRQ Handler.
565 */
566static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
567{
568 struct davinci_spi *dspi;
569 int data_type, ret = -ENOMEM;
570 u32 tx_data, spidat1;
571 u32 errors = 0;
572 struct davinci_spi_config *spicfg;
573 struct davinci_spi_platform_data *pdata;
574
575 dspi = spi_master_get_devdata(spi->master);
576 pdata = &dspi->pdata;
577 spicfg = (struct davinci_spi_config *)spi->controller_data;
578 if (!spicfg)
579 spicfg = &davinci_spi_default_cfg;
580
581 /* convert len to words based on bits_per_word */
582 data_type = dspi->bytes_per_word[spi->chip_select];
583
584 dspi->tx = t->tx_buf;
585 dspi->rx = t->rx_buf;
586 dspi->wcount = t->len / data_type;
587 dspi->rcount = dspi->wcount;
588
589 spidat1 = ioread32(dspi->base + SPIDAT1);
590
591 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
592 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
593
594 reinit_completion(&dspi->done);
595
596 if (!davinci_spi_can_dma(spi->master, spi, t)) {
597 if (spicfg->io_type != SPI_IO_TYPE_POLL)
598 set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
599 /* start the transfer */
600 dspi->wcount--;
601 tx_data = dspi->get_tx(dspi);
602 spidat1 &= 0xFFFF0000;
603 spidat1 |= tx_data & 0xFFFF;
604 iowrite32(spidat1, dspi->base + SPIDAT1);
605 } else {
606 struct dma_slave_config dma_rx_conf = {
607 .direction = DMA_DEV_TO_MEM,
608 .src_addr = (unsigned long)dspi->pbase + SPIBUF,
609 .src_addr_width = data_type,
610 .src_maxburst = 1,
611 };
612 struct dma_slave_config dma_tx_conf = {
613 .direction = DMA_MEM_TO_DEV,
614 .dst_addr = (unsigned long)dspi->pbase + SPIDAT1,
615 .dst_addr_width = data_type,
616 .dst_maxburst = 1,
617 };
618 struct dma_async_tx_descriptor *rxdesc;
619 struct dma_async_tx_descriptor *txdesc;
620
621 dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf);
622 dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf);
623
624 rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx,
625 t->rx_sg.sgl, t->rx_sg.nents, DMA_DEV_TO_MEM,
626 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
627 if (!rxdesc)
628 goto err_desc;
629
630 if (!t->tx_buf) {
631 /* To avoid errors when doing rx-only transfers with
632 * many SG entries (> 20), use the rx buffer as the
633 * dummy tx buffer so that dma reloads are done at the
634 * same time for rx and tx.
635 */
636 t->tx_sg.sgl = t->rx_sg.sgl;
637 t->tx_sg.nents = t->rx_sg.nents;
638 }
639
640 txdesc = dmaengine_prep_slave_sg(dspi->dma_tx,
641 t->tx_sg.sgl, t->tx_sg.nents, DMA_MEM_TO_DEV,
642 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
643 if (!txdesc)
644 goto err_desc;
645
646 rxdesc->callback = davinci_spi_dma_rx_callback;
647 rxdesc->callback_param = (void *)dspi;
648 txdesc->callback = davinci_spi_dma_tx_callback;
649 txdesc->callback_param = (void *)dspi;
650
651 if (pdata->cshold_bug)
652 iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2);
653
654 dmaengine_submit(rxdesc);
655 dmaengine_submit(txdesc);
656
657 dma_async_issue_pending(dspi->dma_rx);
658 dma_async_issue_pending(dspi->dma_tx);
659
660 set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
661 }
662
663 /* Wait for the transfer to complete */
664 if (spicfg->io_type != SPI_IO_TYPE_POLL) {
665 if (wait_for_completion_timeout(&dspi->done, HZ) == 0)
666 errors = SPIFLG_TIMEOUT_MASK;
667 } else {
668 while (dspi->rcount > 0 || dspi->wcount > 0) {
669 errors = davinci_spi_process_events(dspi);
670 if (errors)
671 break;
672 cpu_relax();
673 }
674 }
675
676 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL);
677 if (davinci_spi_can_dma(spi->master, spi, t))
678 clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
679
680 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
681 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
682
683 /*
684 * Check for bit error, desync error,parity error,timeout error and
685 * receive overflow errors
686 */
687 if (errors) {
688 ret = davinci_spi_check_error(dspi, errors);
689 WARN(!ret, "%s: error reported but no error found!\n",
690 dev_name(&spi->dev));
691 return ret;
692 }
693
694 if (dspi->rcount != 0 || dspi->wcount != 0) {
695 dev_err(&spi->dev, "SPI data transfer error\n");
696 return -EIO;
697 }
698
699 return t->len;
700
701err_desc:
702 return ret;
703}
704
705/**
706 * dummy_thread_fn - dummy thread function
707 * @irq: IRQ number for this SPI Master
708 * @data: structure for SPI Master controller davinci_spi
709 *
710 * This is to satisfy the request_threaded_irq() API so that the irq
711 * handler is called in interrupt context.
712 */
713static irqreturn_t dummy_thread_fn(s32 irq, void *data)
714{
715 return IRQ_HANDLED;
716}
717
718/**
719 * davinci_spi_irq - Interrupt handler for SPI Master Controller
720 * @irq: IRQ number for this SPI Master
721 * @data: structure for SPI Master controller davinci_spi
722 *
723 * ISR will determine that interrupt arrives either for READ or WRITE command.
724 * According to command it will do the appropriate action. It will check
725 * transfer length and if it is not zero then dispatch transfer command again.
726 * If transfer length is zero then it will indicate the COMPLETION so that
727 * davinci_spi_bufs function can go ahead.
728 */
729static irqreturn_t davinci_spi_irq(s32 irq, void *data)
730{
731 struct davinci_spi *dspi = data;
732 int status;
733
734 status = davinci_spi_process_events(dspi);
735 if (unlikely(status != 0))
736 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
737
738 if ((!dspi->rcount && !dspi->wcount) || status)
739 complete(&dspi->done);
740
741 return IRQ_HANDLED;
742}
743
744static int davinci_spi_request_dma(struct davinci_spi *dspi)
745{
746 struct device *sdev = dspi->bitbang.master->dev.parent;
747
748 dspi->dma_rx = dma_request_chan(sdev, "rx");
749 if (IS_ERR(dspi->dma_rx))
750 return PTR_ERR(dspi->dma_rx);
751
752 dspi->dma_tx = dma_request_chan(sdev, "tx");
753 if (IS_ERR(dspi->dma_tx)) {
754 dma_release_channel(dspi->dma_rx);
755 return PTR_ERR(dspi->dma_tx);
756 }
757
758 return 0;
759}
760
761#if defined(CONFIG_OF)
762
763/* OF SPI data structure */
764struct davinci_spi_of_data {
765 u8 version;
766 u8 prescaler_limit;
767};
768
769static const struct davinci_spi_of_data dm6441_spi_data = {
770 .version = SPI_VERSION_1,
771 .prescaler_limit = 2,
772};
773
774static const struct davinci_spi_of_data da830_spi_data = {
775 .version = SPI_VERSION_2,
776 .prescaler_limit = 2,
777};
778
779static const struct davinci_spi_of_data keystone_spi_data = {
780 .version = SPI_VERSION_1,
781 .prescaler_limit = 0,
782};
783
784static const struct of_device_id davinci_spi_of_match[] = {
785 {
786 .compatible = "ti,dm6441-spi",
787 .data = &dm6441_spi_data,
788 },
789 {
790 .compatible = "ti,da830-spi",
791 .data = &da830_spi_data,
792 },
793 {
794 .compatible = "ti,keystone-spi",
795 .data = &keystone_spi_data,
796 },
797 { },
798};
799MODULE_DEVICE_TABLE(of, davinci_spi_of_match);
800
801/**
802 * spi_davinci_get_pdata - Get platform data from DTS binding
803 * @pdev: ptr to platform data
804 * @dspi: ptr to driver data
805 *
806 * Parses and populates pdata in dspi from device tree bindings.
807 *
808 * NOTE: Not all platform data params are supported currently.
809 */
810static int spi_davinci_get_pdata(struct platform_device *pdev,
811 struct davinci_spi *dspi)
812{
813 struct device_node *node = pdev->dev.of_node;
814 const struct davinci_spi_of_data *spi_data;
815 struct davinci_spi_platform_data *pdata;
816 unsigned int num_cs, intr_line = 0;
817
818 pdata = &dspi->pdata;
819
820 spi_data = device_get_match_data(&pdev->dev);
821
822 pdata->version = spi_data->version;
823 pdata->prescaler_limit = spi_data->prescaler_limit;
824 /*
825 * default num_cs is 1 and all chipsel are internal to the chip
826 * indicated by chip_sel being NULL or cs_gpios being NULL or
827 * set to -ENOENT. num-cs includes internal as well as gpios.
828 * indicated by chip_sel being NULL. GPIO based CS is not
829 * supported yet in DT bindings.
830 */
831 num_cs = 1;
832 of_property_read_u32(node, "num-cs", &num_cs);
833 pdata->num_chipselect = num_cs;
834 of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line);
835 pdata->intr_line = intr_line;
836 return 0;
837}
838#else
839static int spi_davinci_get_pdata(struct platform_device *pdev,
840 struct davinci_spi *dspi)
841{
842 return -ENODEV;
843}
844#endif
845
846/**
847 * davinci_spi_probe - probe function for SPI Master Controller
848 * @pdev: platform_device structure which contains plateform specific data
849 *
850 * According to Linux Device Model this function will be invoked by Linux
851 * with platform_device struct which contains the device specific info.
852 * This function will map the SPI controller's memory, register IRQ,
853 * Reset SPI controller and setting its registers to default value.
854 * It will invoke spi_bitbang_start to create work queue so that client driver
855 * can register transfer method to work queue.
856 */
857static int davinci_spi_probe(struct platform_device *pdev)
858{
859 struct spi_master *master;
860 struct davinci_spi *dspi;
861 struct davinci_spi_platform_data *pdata;
862 struct resource *r;
863 int ret = 0;
864 u32 spipc0;
865
866 master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
867 if (master == NULL) {
868 ret = -ENOMEM;
869 goto err;
870 }
871
872 platform_set_drvdata(pdev, master);
873
874 dspi = spi_master_get_devdata(master);
875
876 if (dev_get_platdata(&pdev->dev)) {
877 pdata = dev_get_platdata(&pdev->dev);
878 dspi->pdata = *pdata;
879 } else {
880 /* update dspi pdata with that from the DT */
881 ret = spi_davinci_get_pdata(pdev, dspi);
882 if (ret < 0)
883 goto free_master;
884 }
885
886 /* pdata in dspi is now updated and point pdata to that */
887 pdata = &dspi->pdata;
888
889 dspi->bytes_per_word = devm_kcalloc(&pdev->dev,
890 pdata->num_chipselect,
891 sizeof(*dspi->bytes_per_word),
892 GFP_KERNEL);
893 if (dspi->bytes_per_word == NULL) {
894 ret = -ENOMEM;
895 goto free_master;
896 }
897
898 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
899 if (r == NULL) {
900 ret = -ENOENT;
901 goto free_master;
902 }
903
904 dspi->pbase = r->start;
905
906 dspi->base = devm_ioremap_resource(&pdev->dev, r);
907 if (IS_ERR(dspi->base)) {
908 ret = PTR_ERR(dspi->base);
909 goto free_master;
910 }
911
912 init_completion(&dspi->done);
913
914 ret = platform_get_irq(pdev, 0);
915 if (ret == 0)
916 ret = -EINVAL;
917 if (ret < 0)
918 goto free_master;
919 dspi->irq = ret;
920
921 ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq,
922 dummy_thread_fn, 0, dev_name(&pdev->dev), dspi);
923 if (ret)
924 goto free_master;
925
926 dspi->bitbang.master = master;
927
928 dspi->clk = devm_clk_get(&pdev->dev, NULL);
929 if (IS_ERR(dspi->clk)) {
930 ret = -ENODEV;
931 goto free_master;
932 }
933 ret = clk_prepare_enable(dspi->clk);
934 if (ret)
935 goto free_master;
936
937 master->use_gpio_descriptors = true;
938 master->dev.of_node = pdev->dev.of_node;
939 master->bus_num = pdev->id;
940 master->num_chipselect = pdata->num_chipselect;
941 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16);
942 master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_GPIO_SS;
943 master->setup = davinci_spi_setup;
944 master->cleanup = davinci_spi_cleanup;
945 master->can_dma = davinci_spi_can_dma;
946
947 dspi->bitbang.chipselect = davinci_spi_chipselect;
948 dspi->bitbang.setup_transfer = davinci_spi_setup_transfer;
949 dspi->prescaler_limit = pdata->prescaler_limit;
950 dspi->version = pdata->version;
951
952 dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_WORD;
953 if (dspi->version == SPI_VERSION_2)
954 dspi->bitbang.flags |= SPI_READY;
955
956 dspi->bitbang.txrx_bufs = davinci_spi_bufs;
957
958 ret = davinci_spi_request_dma(dspi);
959 if (ret == -EPROBE_DEFER) {
960 goto free_clk;
961 } else if (ret) {
962 dev_info(&pdev->dev, "DMA is not supported (%d)\n", ret);
963 dspi->dma_rx = NULL;
964 dspi->dma_tx = NULL;
965 }
966
967 dspi->get_rx = davinci_spi_rx_buf_u8;
968 dspi->get_tx = davinci_spi_tx_buf_u8;
969
970 /* Reset In/OUT SPI module */
971 iowrite32(0, dspi->base + SPIGCR0);
972 udelay(100);
973 iowrite32(1, dspi->base + SPIGCR0);
974
975 /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */
976 spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK;
977 iowrite32(spipc0, dspi->base + SPIPC0);
978
979 if (pdata->intr_line)
980 iowrite32(SPI_INTLVL_1, dspi->base + SPILVL);
981 else
982 iowrite32(SPI_INTLVL_0, dspi->base + SPILVL);
983
984 iowrite32(CS_DEFAULT, dspi->base + SPIDEF);
985
986 /* master mode default */
987 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK);
988 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
989 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
990
991 ret = spi_bitbang_start(&dspi->bitbang);
992 if (ret)
993 goto free_dma;
994
995 dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base);
996
997 return ret;
998
999free_dma:
1000 if (dspi->dma_rx) {
1001 dma_release_channel(dspi->dma_rx);
1002 dma_release_channel(dspi->dma_tx);
1003 }
1004free_clk:
1005 clk_disable_unprepare(dspi->clk);
1006free_master:
1007 spi_master_put(master);
1008err:
1009 return ret;
1010}
1011
1012/**
1013 * davinci_spi_remove - remove function for SPI Master Controller
1014 * @pdev: platform_device structure which contains plateform specific data
1015 *
1016 * This function will do the reverse action of davinci_spi_probe function
1017 * It will free the IRQ and SPI controller's memory region.
1018 * It will also call spi_bitbang_stop to destroy the work queue which was
1019 * created by spi_bitbang_start.
1020 */
1021static int davinci_spi_remove(struct platform_device *pdev)
1022{
1023 struct davinci_spi *dspi;
1024 struct spi_master *master;
1025
1026 master = platform_get_drvdata(pdev);
1027 dspi = spi_master_get_devdata(master);
1028
1029 spi_bitbang_stop(&dspi->bitbang);
1030
1031 clk_disable_unprepare(dspi->clk);
1032
1033 if (dspi->dma_rx) {
1034 dma_release_channel(dspi->dma_rx);
1035 dma_release_channel(dspi->dma_tx);
1036 }
1037
1038 spi_master_put(master);
1039 return 0;
1040}
1041
1042static struct platform_driver davinci_spi_driver = {
1043 .driver = {
1044 .name = "spi_davinci",
1045 .of_match_table = of_match_ptr(davinci_spi_of_match),
1046 },
1047 .probe = davinci_spi_probe,
1048 .remove = davinci_spi_remove,
1049};
1050module_platform_driver(davinci_spi_driver);
1051
1052MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
1053MODULE_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");