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  1/*
  2 * SH RSPI driver
  3 *
  4 * Copyright (C) 2012  Renesas Solutions Corp.
  5 *
  6 * Based on spi-sh.c:
  7 * Copyright (C) 2011 Renesas Solutions Corp.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; version 2 of the License.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program; if not, write to the Free Software
 20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 21 *
 22 */
 23
 24#include <linux/module.h>
 25#include <linux/kernel.h>
 26#include <linux/sched.h>
 27#include <linux/errno.h>
 28#include <linux/list.h>
 29#include <linux/workqueue.h>
 30#include <linux/interrupt.h>
 31#include <linux/platform_device.h>
 32#include <linux/io.h>
 33#include <linux/clk.h>
 34#include <linux/dmaengine.h>
 35#include <linux/dma-mapping.h>
 36#include <linux/sh_dma.h>
 37#include <linux/spi/spi.h>
 38#include <linux/spi/rspi.h>
 39
 40#define RSPI_SPCR		0x00
 41#define RSPI_SSLP		0x01
 42#define RSPI_SPPCR		0x02
 43#define RSPI_SPSR		0x03
 44#define RSPI_SPDR		0x04
 45#define RSPI_SPSCR		0x08
 46#define RSPI_SPSSR		0x09
 47#define RSPI_SPBR		0x0a
 48#define RSPI_SPDCR		0x0b
 49#define RSPI_SPCKD		0x0c
 50#define RSPI_SSLND		0x0d
 51#define RSPI_SPND		0x0e
 52#define RSPI_SPCR2		0x0f
 53#define RSPI_SPCMD0		0x10
 54#define RSPI_SPCMD1		0x12
 55#define RSPI_SPCMD2		0x14
 56#define RSPI_SPCMD3		0x16
 57#define RSPI_SPCMD4		0x18
 58#define RSPI_SPCMD5		0x1a
 59#define RSPI_SPCMD6		0x1c
 60#define RSPI_SPCMD7		0x1e
 61
 62/* SPCR */
 63#define SPCR_SPRIE		0x80
 64#define SPCR_SPE		0x40
 65#define SPCR_SPTIE		0x20
 66#define SPCR_SPEIE		0x10
 67#define SPCR_MSTR		0x08
 68#define SPCR_MODFEN		0x04
 69#define SPCR_TXMD		0x02
 70#define SPCR_SPMS		0x01
 71
 72/* SSLP */
 73#define SSLP_SSL1P		0x02
 74#define SSLP_SSL0P		0x01
 75
 76/* SPPCR */
 77#define SPPCR_MOIFE		0x20
 78#define SPPCR_MOIFV		0x10
 79#define SPPCR_SPOM		0x04
 80#define SPPCR_SPLP2		0x02
 81#define SPPCR_SPLP		0x01
 82
 83/* SPSR */
 84#define SPSR_SPRF		0x80
 85#define SPSR_SPTEF		0x20
 86#define SPSR_PERF		0x08
 87#define SPSR_MODF		0x04
 88#define SPSR_IDLNF		0x02
 89#define SPSR_OVRF		0x01
 90
 91/* SPSCR */
 92#define SPSCR_SPSLN_MASK	0x07
 93
 94/* SPSSR */
 95#define SPSSR_SPECM_MASK	0x70
 96#define SPSSR_SPCP_MASK		0x07
 97
 98/* SPDCR */
 99#define SPDCR_SPLW		0x20
100#define SPDCR_SPRDTD		0x10
101#define SPDCR_SLSEL1		0x08
102#define SPDCR_SLSEL0		0x04
103#define SPDCR_SLSEL_MASK	0x0c
104#define SPDCR_SPFC1		0x02
105#define SPDCR_SPFC0		0x01
106
107/* SPCKD */
108#define SPCKD_SCKDL_MASK	0x07
109
110/* SSLND */
111#define SSLND_SLNDL_MASK	0x07
112
113/* SPND */
114#define SPND_SPNDL_MASK		0x07
115
116/* SPCR2 */
117#define SPCR2_PTE		0x08
118#define SPCR2_SPIE		0x04
119#define SPCR2_SPOE		0x02
120#define SPCR2_SPPE		0x01
121
122/* SPCMDn */
123#define SPCMD_SCKDEN		0x8000
124#define SPCMD_SLNDEN		0x4000
125#define SPCMD_SPNDEN		0x2000
126#define SPCMD_LSBF		0x1000
127#define SPCMD_SPB_MASK		0x0f00
128#define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
129#define SPCMD_SPB_20BIT		0x0000
130#define SPCMD_SPB_24BIT		0x0100
131#define SPCMD_SPB_32BIT		0x0200
132#define SPCMD_SSLKP		0x0080
133#define SPCMD_SSLA_MASK		0x0030
134#define SPCMD_BRDV_MASK		0x000c
135#define SPCMD_CPOL		0x0002
136#define SPCMD_CPHA		0x0001
137
138struct rspi_data {
139	void __iomem *addr;
140	u32 max_speed_hz;
141	struct spi_master *master;
142	struct list_head queue;
143	struct work_struct ws;
144	wait_queue_head_t wait;
145	spinlock_t lock;
146	struct clk *clk;
147	unsigned char spsr;
148
149	/* for dmaengine */
150	struct sh_dmae_slave dma_tx;
151	struct sh_dmae_slave dma_rx;
152	struct dma_chan *chan_tx;
153	struct dma_chan *chan_rx;
154	int irq;
155
156	unsigned dma_width_16bit:1;
157	unsigned dma_callbacked:1;
158};
159
160static void rspi_write8(struct rspi_data *rspi, u8 data, u16 offset)
161{
162	iowrite8(data, rspi->addr + offset);
163}
164
165static void rspi_write16(struct rspi_data *rspi, u16 data, u16 offset)
166{
167	iowrite16(data, rspi->addr + offset);
168}
169
170static u8 rspi_read8(struct rspi_data *rspi, u16 offset)
171{
172	return ioread8(rspi->addr + offset);
173}
174
175static u16 rspi_read16(struct rspi_data *rspi, u16 offset)
176{
177	return ioread16(rspi->addr + offset);
178}
179
180static unsigned char rspi_calc_spbr(struct rspi_data *rspi)
181{
182	int tmp;
183	unsigned char spbr;
184
185	tmp = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
186	spbr = clamp(tmp, 0, 255);
187
188	return spbr;
189}
190
191static void rspi_enable_irq(struct rspi_data *rspi, u8 enable)
192{
193	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
194}
195
196static void rspi_disable_irq(struct rspi_data *rspi, u8 disable)
197{
198	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
199}
200
201static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
202				   u8 enable_bit)
203{
204	int ret;
205
206	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
207	rspi_enable_irq(rspi, enable_bit);
208	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
209	if (ret == 0 && !(rspi->spsr & wait_mask))
210		return -ETIMEDOUT;
211
212	return 0;
213}
214
215static void rspi_assert_ssl(struct rspi_data *rspi)
216{
217	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
218}
219
220static void rspi_negate_ssl(struct rspi_data *rspi)
221{
222	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
223}
224
225static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
226{
227	/* Sets output mode(CMOS) and MOSI signal(from previous transfer) */
228	rspi_write8(rspi, 0x00, RSPI_SPPCR);
229
230	/* Sets transfer bit rate */
231	rspi_write8(rspi, rspi_calc_spbr(rspi), RSPI_SPBR);
232
233	/* Sets number of frames to be used: 1 frame */
234	rspi_write8(rspi, 0x00, RSPI_SPDCR);
235
236	/* Sets RSPCK, SSL, next-access delay value */
237	rspi_write8(rspi, 0x00, RSPI_SPCKD);
238	rspi_write8(rspi, 0x00, RSPI_SSLND);
239	rspi_write8(rspi, 0x00, RSPI_SPND);
240
241	/* Sets parity, interrupt mask */
242	rspi_write8(rspi, 0x00, RSPI_SPCR2);
243
244	/* Sets SPCMD */
245	rspi_write16(rspi, SPCMD_SPB_8_TO_16(access_size) | SPCMD_SSLKP,
246		     RSPI_SPCMD0);
247
248	/* Sets RSPI mode */
249	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
250
251	return 0;
252}
253
254static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg,
255			 struct spi_transfer *t)
256{
257	int remain = t->len;
258	u8 *data;
259
260	data = (u8 *)t->tx_buf;
261	while (remain > 0) {
262		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD,
263			    RSPI_SPCR);
264
265		if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
266			dev_err(&rspi->master->dev,
267				"%s: tx empty timeout\n", __func__);
268			return -ETIMEDOUT;
269		}
270
271		rspi_write16(rspi, *data, RSPI_SPDR);
272		data++;
273		remain--;
274	}
275
276	/* Waiting for the last transmition */
277	rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
278
279	return 0;
280}
281
282static void rspi_dma_complete(void *arg)
283{
284	struct rspi_data *rspi = arg;
285
286	rspi->dma_callbacked = 1;
287	wake_up_interruptible(&rspi->wait);
288}
289
290static int rspi_dma_map_sg(struct scatterlist *sg, void *buf, unsigned len,
291			   struct dma_chan *chan,
292			   enum dma_transfer_direction dir)
293{
294	sg_init_table(sg, 1);
295	sg_set_buf(sg, buf, len);
296	sg_dma_len(sg) = len;
297	return dma_map_sg(chan->device->dev, sg, 1, dir);
298}
299
300static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
301			      enum dma_transfer_direction dir)
302{
303	dma_unmap_sg(chan->device->dev, sg, 1, dir);
304}
305
306static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len)
307{
308	u16 *dst = buf;
309	const u8 *src = data;
310
311	while (len) {
312		*dst++ = (u16)(*src++);
313		len--;
314	}
315}
316
317static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len)
318{
319	u8 *dst = buf;
320	const u16 *src = data;
321
322	while (len) {
323		*dst++ = (u8)*src++;
324		len--;
325	}
326}
327
328static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
329{
330	struct scatterlist sg;
331	void *buf = NULL;
332	struct dma_async_tx_descriptor *desc;
333	unsigned len;
334	int ret = 0;
335
336	if (rspi->dma_width_16bit) {
337		/*
338		 * If DMAC bus width is 16-bit, the driver allocates a dummy
339		 * buffer. And, the driver converts original data into the
340		 * DMAC data as the following format:
341		 *  original data: 1st byte, 2nd byte ...
342		 *  DMAC data:     1st byte, dummy, 2nd byte, dummy ...
343		 */
344		len = t->len * 2;
345		buf = kmalloc(len, GFP_KERNEL);
346		if (!buf)
347			return -ENOMEM;
348		rspi_memory_to_8bit(buf, t->tx_buf, t->len);
349	} else {
350		len = t->len;
351		buf = (void *)t->tx_buf;
352	}
353
354	if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) {
355		ret = -EFAULT;
356		goto end_nomap;
357	}
358	desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
359				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
360	if (!desc) {
361		ret = -EIO;
362		goto end;
363	}
364
365	/*
366	 * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
367	 * called. So, this driver disables the IRQ while DMA transfer.
368	 */
369	disable_irq(rspi->irq);
370
371	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR);
372	rspi_enable_irq(rspi, SPCR_SPTIE);
373	rspi->dma_callbacked = 0;
374
375	desc->callback = rspi_dma_complete;
376	desc->callback_param = rspi;
377	dmaengine_submit(desc);
378	dma_async_issue_pending(rspi->chan_tx);
379
380	ret = wait_event_interruptible_timeout(rspi->wait,
381					       rspi->dma_callbacked, HZ);
382	if (ret > 0 && rspi->dma_callbacked)
383		ret = 0;
384	else if (!ret)
385		ret = -ETIMEDOUT;
386	rspi_disable_irq(rspi, SPCR_SPTIE);
387
388	enable_irq(rspi->irq);
389
390end:
391	rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
392end_nomap:
393	if (rspi->dma_width_16bit)
394		kfree(buf);
395
396	return ret;
397}
398
399static void rspi_receive_init(struct rspi_data *rspi)
400{
401	unsigned char spsr;
402
403	spsr = rspi_read8(rspi, RSPI_SPSR);
404	if (spsr & SPSR_SPRF)
405		rspi_read16(rspi, RSPI_SPDR);	/* dummy read */
406	if (spsr & SPSR_OVRF)
407		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
408			    RSPI_SPCR);
409}
410
411static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg,
412			    struct spi_transfer *t)
413{
414	int remain = t->len;
415	u8 *data;
416
417	rspi_receive_init(rspi);
418
419	data = (u8 *)t->rx_buf;
420	while (remain > 0) {
421		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD,
422			    RSPI_SPCR);
423
424		if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
425			dev_err(&rspi->master->dev,
426				"%s: tx empty timeout\n", __func__);
427			return -ETIMEDOUT;
428		}
429		/* dummy write for generate clock */
430		rspi_write16(rspi, 0x00, RSPI_SPDR);
431
432		if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
433			dev_err(&rspi->master->dev,
434				"%s: receive timeout\n", __func__);
435			return -ETIMEDOUT;
436		}
437		/* SPDR allows 16 or 32-bit access only */
438		*data = (u8)rspi_read16(rspi, RSPI_SPDR);
439
440		data++;
441		remain--;
442	}
443
444	return 0;
445}
446
447static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
448{
449	struct scatterlist sg, sg_dummy;
450	void *dummy = NULL, *rx_buf = NULL;
451	struct dma_async_tx_descriptor *desc, *desc_dummy;
452	unsigned len;
453	int ret = 0;
454
455	if (rspi->dma_width_16bit) {
456		/*
457		 * If DMAC bus width is 16-bit, the driver allocates a dummy
458		 * buffer. And, finally the driver converts the DMAC data into
459		 * actual data as the following format:
460		 *  DMAC data:   1st byte, dummy, 2nd byte, dummy ...
461		 *  actual data: 1st byte, 2nd byte ...
462		 */
463		len = t->len * 2;
464		rx_buf = kmalloc(len, GFP_KERNEL);
465		if (!rx_buf)
466			return -ENOMEM;
467	 } else {
468		len = t->len;
469		rx_buf = t->rx_buf;
470	}
471
472	/* prepare dummy transfer to generate SPI clocks */
473	dummy = kzalloc(len, GFP_KERNEL);
474	if (!dummy) {
475		ret = -ENOMEM;
476		goto end_nomap;
477	}
478	if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx,
479			     DMA_TO_DEVICE)) {
480		ret = -EFAULT;
481		goto end_nomap;
482	}
483	desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1,
484			DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
485	if (!desc_dummy) {
486		ret = -EIO;
487		goto end_dummy_mapped;
488	}
489
490	/* prepare receive transfer */
491	if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx,
492			     DMA_FROM_DEVICE)) {
493		ret = -EFAULT;
494		goto end_dummy_mapped;
495
496	}
497	desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE,
498				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
499	if (!desc) {
500		ret = -EIO;
501		goto end;
502	}
503
504	rspi_receive_init(rspi);
505
506	/*
507	 * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
508	 * called. So, this driver disables the IRQ while DMA transfer.
509	 */
510	disable_irq(rspi->irq);
511
512	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR);
513	rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
514	rspi->dma_callbacked = 0;
515
516	desc->callback = rspi_dma_complete;
517	desc->callback_param = rspi;
518	dmaengine_submit(desc);
519	dma_async_issue_pending(rspi->chan_rx);
520
521	desc_dummy->callback = NULL;	/* No callback */
522	dmaengine_submit(desc_dummy);
523	dma_async_issue_pending(rspi->chan_tx);
524
525	ret = wait_event_interruptible_timeout(rspi->wait,
526					       rspi->dma_callbacked, HZ);
527	if (ret > 0 && rspi->dma_callbacked)
528		ret = 0;
529	else if (!ret)
530		ret = -ETIMEDOUT;
531	rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
532
533	enable_irq(rspi->irq);
534
535end:
536	rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);
537end_dummy_mapped:
538	rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);
539end_nomap:
540	if (rspi->dma_width_16bit) {
541		if (!ret)
542			rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len);
543		kfree(rx_buf);
544	}
545	kfree(dummy);
546
547	return ret;
548}
549
550static int rspi_is_dma(struct rspi_data *rspi, struct spi_transfer *t)
551{
552	if (t->tx_buf && rspi->chan_tx)
553		return 1;
554	/* If the module receives data by DMAC, it also needs TX DMAC */
555	if (t->rx_buf && rspi->chan_tx && rspi->chan_rx)
556		return 1;
557
558	return 0;
559}
560
561static void rspi_work(struct work_struct *work)
562{
563	struct rspi_data *rspi = container_of(work, struct rspi_data, ws);
564	struct spi_message *mesg;
565	struct spi_transfer *t;
566	unsigned long flags;
567	int ret;
568
569	spin_lock_irqsave(&rspi->lock, flags);
570	while (!list_empty(&rspi->queue)) {
571		mesg = list_entry(rspi->queue.next, struct spi_message, queue);
572		list_del_init(&mesg->queue);
573		spin_unlock_irqrestore(&rspi->lock, flags);
574
575		rspi_assert_ssl(rspi);
576
577		list_for_each_entry(t, &mesg->transfers, transfer_list) {
578			if (t->tx_buf) {
579				if (rspi_is_dma(rspi, t))
580					ret = rspi_send_dma(rspi, t);
581				else
582					ret = rspi_send_pio(rspi, mesg, t);
583				if (ret < 0)
584					goto error;
585			}
586			if (t->rx_buf) {
587				if (rspi_is_dma(rspi, t))
588					ret = rspi_receive_dma(rspi, t);
589				else
590					ret = rspi_receive_pio(rspi, mesg, t);
591				if (ret < 0)
592					goto error;
593			}
594			mesg->actual_length += t->len;
595		}
596		rspi_negate_ssl(rspi);
597
598		mesg->status = 0;
599		mesg->complete(mesg->context);
600
601		spin_lock_irqsave(&rspi->lock, flags);
602	}
603
604	return;
605
606error:
607	mesg->status = ret;
608	mesg->complete(mesg->context);
609}
610
611static int rspi_setup(struct spi_device *spi)
612{
613	struct rspi_data *rspi = spi_master_get_devdata(spi->master);
614
615	if (!spi->bits_per_word)
616		spi->bits_per_word = 8;
617	rspi->max_speed_hz = spi->max_speed_hz;
618
619	rspi_set_config_register(rspi, 8);
620
621	return 0;
622}
623
624static int rspi_transfer(struct spi_device *spi, struct spi_message *mesg)
625{
626	struct rspi_data *rspi = spi_master_get_devdata(spi->master);
627	unsigned long flags;
628
629	mesg->actual_length = 0;
630	mesg->status = -EINPROGRESS;
631
632	spin_lock_irqsave(&rspi->lock, flags);
633	list_add_tail(&mesg->queue, &rspi->queue);
634	schedule_work(&rspi->ws);
635	spin_unlock_irqrestore(&rspi->lock, flags);
636
637	return 0;
638}
639
640static void rspi_cleanup(struct spi_device *spi)
641{
642}
643
644static irqreturn_t rspi_irq(int irq, void *_sr)
645{
646	struct rspi_data *rspi = (struct rspi_data *)_sr;
647	unsigned long spsr;
648	irqreturn_t ret = IRQ_NONE;
649	unsigned char disable_irq = 0;
650
651	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
652	if (spsr & SPSR_SPRF)
653		disable_irq |= SPCR_SPRIE;
654	if (spsr & SPSR_SPTEF)
655		disable_irq |= SPCR_SPTIE;
656
657	if (disable_irq) {
658		ret = IRQ_HANDLED;
659		rspi_disable_irq(rspi, disable_irq);
660		wake_up(&rspi->wait);
661	}
662
663	return ret;
664}
665
666static bool rspi_filter(struct dma_chan *chan, void *filter_param)
667{
668	chan->private = filter_param;
669	return true;
670}
671
672static void __devinit rspi_request_dma(struct rspi_data *rspi,
673				       struct platform_device *pdev)
674{
675	struct rspi_plat_data *rspi_pd = pdev->dev.platform_data;
676	dma_cap_mask_t mask;
677
678	if (!rspi_pd)
679		return;
680
681	rspi->dma_width_16bit = rspi_pd->dma_width_16bit;
682
683	/* If the module receives data by DMAC, it also needs TX DMAC */
684	if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
685		dma_cap_zero(mask);
686		dma_cap_set(DMA_SLAVE, mask);
687		rspi->dma_rx.slave_id = rspi_pd->dma_rx_id;
688		rspi->chan_rx = dma_request_channel(mask, rspi_filter,
689						    &rspi->dma_rx);
690		if (rspi->chan_rx)
691			dev_info(&pdev->dev, "Use DMA when rx.\n");
692	}
693	if (rspi_pd->dma_tx_id) {
694		dma_cap_zero(mask);
695		dma_cap_set(DMA_SLAVE, mask);
696		rspi->dma_tx.slave_id = rspi_pd->dma_tx_id;
697		rspi->chan_tx = dma_request_channel(mask, rspi_filter,
698						    &rspi->dma_tx);
699		if (rspi->chan_tx)
700			dev_info(&pdev->dev, "Use DMA when tx\n");
701	}
702}
703
704static void __devexit rspi_release_dma(struct rspi_data *rspi)
705{
706	if (rspi->chan_tx)
707		dma_release_channel(rspi->chan_tx);
708	if (rspi->chan_rx)
709		dma_release_channel(rspi->chan_rx);
710}
711
712static int __devexit rspi_remove(struct platform_device *pdev)
713{
714	struct rspi_data *rspi = dev_get_drvdata(&pdev->dev);
715
716	spi_unregister_master(rspi->master);
717	rspi_release_dma(rspi);
718	free_irq(platform_get_irq(pdev, 0), rspi);
719	clk_put(rspi->clk);
720	iounmap(rspi->addr);
721	spi_master_put(rspi->master);
722
723	return 0;
724}
725
726static int __devinit rspi_probe(struct platform_device *pdev)
727{
728	struct resource *res;
729	struct spi_master *master;
730	struct rspi_data *rspi;
731	int ret, irq;
732	char clk_name[16];
733
734	/* get base addr */
735	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
736	if (unlikely(res == NULL)) {
737		dev_err(&pdev->dev, "invalid resource\n");
738		return -EINVAL;
739	}
740
741	irq = platform_get_irq(pdev, 0);
742	if (irq < 0) {
743		dev_err(&pdev->dev, "platform_get_irq error\n");
744		return -ENODEV;
745	}
746
747	master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
748	if (master == NULL) {
749		dev_err(&pdev->dev, "spi_alloc_master error.\n");
750		return -ENOMEM;
751	}
752
753	rspi = spi_master_get_devdata(master);
754	dev_set_drvdata(&pdev->dev, rspi);
755
756	rspi->master = master;
757	rspi->addr = ioremap(res->start, resource_size(res));
758	if (rspi->addr == NULL) {
759		dev_err(&pdev->dev, "ioremap error.\n");
760		ret = -ENOMEM;
761		goto error1;
762	}
763
764	snprintf(clk_name, sizeof(clk_name), "rspi%d", pdev->id);
765	rspi->clk = clk_get(&pdev->dev, clk_name);
766	if (IS_ERR(rspi->clk)) {
767		dev_err(&pdev->dev, "cannot get clock\n");
768		ret = PTR_ERR(rspi->clk);
769		goto error2;
770	}
771	clk_enable(rspi->clk);
772
773	INIT_LIST_HEAD(&rspi->queue);
774	spin_lock_init(&rspi->lock);
775	INIT_WORK(&rspi->ws, rspi_work);
776	init_waitqueue_head(&rspi->wait);
777
778	master->num_chipselect = 2;
779	master->bus_num = pdev->id;
780	master->setup = rspi_setup;
781	master->transfer = rspi_transfer;
782	master->cleanup = rspi_cleanup;
783
784	ret = request_irq(irq, rspi_irq, 0, dev_name(&pdev->dev), rspi);
785	if (ret < 0) {
786		dev_err(&pdev->dev, "request_irq error\n");
787		goto error3;
788	}
789
790	rspi->irq = irq;
791	rspi_request_dma(rspi, pdev);
792
793	ret = spi_register_master(master);
794	if (ret < 0) {
795		dev_err(&pdev->dev, "spi_register_master error.\n");
796		goto error4;
797	}
798
799	dev_info(&pdev->dev, "probed\n");
800
801	return 0;
802
803error4:
804	rspi_release_dma(rspi);
805	free_irq(irq, rspi);
806error3:
807	clk_put(rspi->clk);
808error2:
809	iounmap(rspi->addr);
810error1:
811	spi_master_put(master);
812
813	return ret;
814}
815
816static struct platform_driver rspi_driver = {
817	.probe =	rspi_probe,
818	.remove =	__devexit_p(rspi_remove),
819	.driver		= {
820		.name = "rspi",
821		.owner	= THIS_MODULE,
822	},
823};
824module_platform_driver(rspi_driver);
825
826MODULE_DESCRIPTION("Renesas RSPI bus driver");
827MODULE_LICENSE("GPL v2");
828MODULE_AUTHOR("Yoshihiro Shimoda");
829MODULE_ALIAS("platform:rspi");