LXR linux/drivers/media/i2c/s5c73m3/s5c73m3-spi.c

   1/*
   2 * Samsung LSI S5C73M3 8M pixel camera driver
   3 *
   4 * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
   5 * Sylwester Nawrocki <s.nawrocki@samsung.com>
   6 * Andrzej Hajda <a.hajda@samsung.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * version 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/sizes.h>
  19#include <linux/delay.h>
  20#include <linux/init.h>
  21#include <linux/media.h>
  22#include <linux/module.h>
  23#include <linux/slab.h>
  24#include <linux/spi/spi.h>
  25
  26#include "s5c73m3.h"
  27
  28#define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"
  29
  30static const struct of_device_id s5c73m3_spi_ids[] = {
  31        { .compatible = "samsung,s5c73m3" },
  32        { }
  33};
  34MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);
  35
  36enum spi_direction {
  37        SPI_DIR_RX,
  38        SPI_DIR_TX
  39};
  40
  41static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
  42                                                        enum spi_direction dir)
  43{
  44        struct spi_message msg;
  45        int r;
  46        struct spi_transfer xfer = {
  47                .len    = len,
  48        };
  49
  50        if (dir == SPI_DIR_TX)
  51                xfer.tx_buf = addr;
  52        else
  53                xfer.rx_buf = addr;
  54
  55        if (spi_dev == NULL) {
  56                pr_err("SPI device is uninitialized\n");
  57                return -ENODEV;
  58        }
  59
  60        spi_message_init(&msg);
  61        spi_message_add_tail(&xfer, &msg);
  62
  63        r = spi_sync(spi_dev, &msg);
  64        if (r < 0)
  65                dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
  66
  67        return r;
  68}
  69
  70int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
  71                      const unsigned int len, const unsigned int tx_size)
  72{
  73        struct spi_device *spi_dev = state->spi_dev;
  74        u32 count = len / tx_size;
  75        u32 extra = len % tx_size;
  76        unsigned int i, j = 0;
  77        u8 padding[32];
  78        int r = 0;
  79
  80        memset(padding, 0, sizeof(padding));
  81
  82        for (i = 0; i < count; i++) {
  83                r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
  84                if (r < 0)
  85                        return r;
  86                j += tx_size;
  87        }
  88
  89        if (extra > 0) {
  90                r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
  91                if (r < 0)
  92                        return r;
  93        }
  94
  95        return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
  96}
  97
  98int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
  99                     const unsigned int len, const unsigned int tx_size)
 100{
 101        struct spi_device *spi_dev = state->spi_dev;
 102        u32 count = len / tx_size;
 103        u32 extra = len % tx_size;
 104        unsigned int i, j = 0;
 105        int r = 0;
 106
 107        for (i = 0; i < count; i++) {
 108                r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
 109                if (r < 0)
 110                        return r;
 111                j += tx_size;
 112        }
 113
 114        if (extra > 0)
 115                return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
 116
 117        return 0;
 118}
 119
 120static int s5c73m3_spi_probe(struct spi_device *spi)
 121{
 122        int r;
 123        struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
 124                                             spidrv.driver);
 125        spi->bits_per_word = 32;
 126
 127        r = spi_setup(spi);
 128        if (r < 0) {
 129                dev_err(&spi->dev, "spi_setup() failed\n");
 130                return r;
 131        }
 132
 133        mutex_lock(&state->lock);
 134        state->spi_dev = spi;
 135        mutex_unlock(&state->lock);
 136
 137        v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
 138        return 0;
 139}
 140
 141static int s5c73m3_spi_remove(struct spi_device *spi)
 142{
 143        return 0;
 144}
 145
 146int s5c73m3_register_spi_driver(struct s5c73m3 *state)
 147{
 148        struct spi_driver *spidrv = &state->spidrv;
 149
 150        spidrv->remove = s5c73m3_spi_remove;
 151        spidrv->probe = s5c73m3_spi_probe;
 152        spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
 153        spidrv->driver.of_match_table = s5c73m3_spi_ids;
 154
 155        return spi_register_driver(spidrv);
 156}
 157
 158void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
 159{
 160        spi_unregister_driver(&state->spidrv);
 161}
 162