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};
  34
  35enum spi_direction {
  36        SPI_DIR_RX,
  37        SPI_DIR_TX
  38};
  39
  40static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
  41                                                        enum spi_direction dir)
  42{
  43        struct spi_message msg;
  44        int r;
  45        struct spi_transfer xfer = {
  46                .len    = len,
  47        };
  48
  49        if (dir == SPI_DIR_TX)
  50                xfer.tx_buf = addr;
  51        else
  52                xfer.rx_buf = addr;
  53
  54        if (spi_dev == NULL) {
  55                pr_err("SPI device is uninitialized\n");
  56                return -ENODEV;
  57        }
  58
  59        spi_message_init(&msg);
  60        spi_message_add_tail(&xfer, &msg);
  61
  62        r = spi_sync(spi_dev, &msg);
  63        if (r < 0)
  64                dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
  65
  66        return r;
  67}
  68
  69int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
  70                      const unsigned int len, const unsigned int tx_size)
  71{
  72        struct spi_device *spi_dev = state->spi_dev;
  73        u32 count = len / tx_size;
  74        u32 extra = len % tx_size;
  75        unsigned int i, j = 0;
  76        u8 padding[32];
  77        int r = 0;
  78
  79        memset(padding, 0, sizeof(padding));
  80
  81        for (i = 0; i < count; i++) {
  82                r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
  83                if (r < 0)
  84                        return r;
  85                j += tx_size;
  86        }
  87
  88        if (extra > 0) {
  89                r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
  90                if (r < 0)
  91                        return r;
  92        }
  93
  94        return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
  95}
  96
  97int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
  98                     const unsigned int len, const unsigned int tx_size)
  99{
 100        struct spi_device *spi_dev = state->spi_dev;
 101        u32 count = len / tx_size;
 102        u32 extra = len % tx_size;
 103        unsigned int i, j = 0;
 104        int r = 0;
 105
 106        for (i = 0; i < count; i++) {
 107                r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
 108                if (r < 0)
 109                        return r;
 110                j += tx_size;
 111        }
 112
 113        if (extra > 0)
 114                return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
 115
 116        return 0;
 117}
 118
 119static int s5c73m3_spi_probe(struct spi_device *spi)
 120{
 121        int r;
 122        struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
 123                                             spidrv.driver);
 124        spi->bits_per_word = 32;
 125
 126        r = spi_setup(spi);
 127        if (r < 0) {
 128                dev_err(&spi->dev, "spi_setup() failed\n");
 129                return r;
 130        }
 131
 132        mutex_lock(&state->lock);
 133        state->spi_dev = spi;
 134        mutex_unlock(&state->lock);
 135
 136        v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
 137        return 0;
 138}
 139
 140static int s5c73m3_spi_remove(struct spi_device *spi)
 141{
 142        return 0;
 143}
 144
 145int s5c73m3_register_spi_driver(struct s5c73m3 *state)
 146{
 147        struct spi_driver *spidrv = &state->spidrv;
 148
 149        spidrv->remove = s5c73m3_spi_remove;
 150        spidrv->probe = s5c73m3_spi_probe;
 151        spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
 152        spidrv->driver.owner = THIS_MODULE;
 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