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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Samsung LSI S5C73M3 8M pixel camera driver
   4  *
   5  * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
   6  * Sylwester Nawrocki <s.nawrocki@samsung.com>
   7  * Andrzej Hajda <a.hajda@samsung.com>
   8  */
   9
  10 #include <linux/sizes.h>
  11 #include <linux/delay.h>
  12 #include <linux/init.h>
  13 #include <linux/media.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/spi/spi.h>
  17
  18 #include "s5c73m3.h"
  19
  20 #define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"
  21
  22 static const struct of_device_id s5c73m3_spi_ids[] = {
  23         { .compatible = "samsung,s5c73m3" },
  24         { }
  25 };
  26 MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);
  27
  28 enum spi_direction {
  29         SPI_DIR_RX,
  30         SPI_DIR_TX
  31 };
  32
  33 static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
  34                                                         enum spi_direction dir)
  35 {
  36         struct spi_message msg;
  37         int r;
  38         struct spi_transfer xfer = {
  39                 .len    = len,
  40         };
  41
  42         if (dir == SPI_DIR_TX)
  43                 xfer.tx_buf = addr;
  44         else
  45                 xfer.rx_buf = addr;
  46
  47         if (spi_dev == NULL) {
  48                 pr_err("SPI device is uninitialized\n");
  49                 return -ENODEV;
  50         }
  51
  52         spi_message_init(&msg);
  53         spi_message_add_tail(&xfer, &msg);
  54
  55         r = spi_sync(spi_dev, &msg);
  56         if (r < 0)
  57                 dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
  58
  59         return r;
  60 }
  61
  62 int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
  63                       const unsigned int len, const unsigned int tx_size)
  64 {
  65         struct spi_device *spi_dev = state->spi_dev;
  66         u32 count = len / tx_size;
  67         u32 extra = len % tx_size;
  68         unsigned int i, j = 0;
  69         u8 padding[32];
  70         int r = 0;
  71
  72         memset(padding, 0, sizeof(padding));
  73
  74         for (i = 0; i < count; i++) {
  75                 r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
  76                 if (r < 0)
  77                         return r;
  78                 j += tx_size;
  79         }
  80
  81         if (extra > 0) {
  82                 r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
  83                 if (r < 0)
  84                         return r;
  85         }
  86
  87         return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
  88 }
  89
  90 int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
  91                      const unsigned int len, const unsigned int tx_size)
  92 {
  93         struct spi_device *spi_dev = state->spi_dev;
  94         u32 count = len / tx_size;
  95         u32 extra = len % tx_size;
  96         unsigned int i, j = 0;
  97         int r = 0;
  98
  99         for (i = 0; i < count; i++) {
 100                 r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
 101                 if (r < 0)
 102                         return r;
 103                 j += tx_size;
 104         }
 105
 106         if (extra > 0)
 107                 return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
 108
 109         return 0;
 110 }
 111
 112 static int s5c73m3_spi_probe(struct spi_device *spi)
 113 {
 114         int r;
 115         struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
 116                                              spidrv.driver);
 117         spi->bits_per_word = 32;
 118
 119         r = spi_setup(spi);
 120         if (r < 0) {
 121                 dev_err(&spi->dev, "spi_setup() failed\n");
 122                 return r;
 123         }
 124
 125         mutex_lock(&state->lock);
 126         state->spi_dev = spi;
 127         mutex_unlock(&state->lock);
 128
 129         v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
 130         return 0;
 131 }
 132
 133 int s5c73m3_register_spi_driver(struct s5c73m3 *state)
 134 {
 135         struct spi_driver *spidrv = &state->spidrv;
 136
 137         spidrv->probe = s5c73m3_spi_probe;
 138         spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
 139         spidrv->driver.of_match_table = s5c73m3_spi_ids;
 140
 141         return spi_register_driver(spidrv);
 142 }
 143
 144 void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
 145 {
 146         spi_unregister_driver(&state->spidrv);
 147 }