Root/drivers/spi/spi-rspi.c

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");
830

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