drivers/media/i2c/ov7640.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005-2006 Micronas USA Inc.
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/module.h>
   8 #include <linux/i2c.h>
   9 #include <linux/videodev2.h>
  10 #include <media/v4l2-device.h>
  11 #include <linux/slab.h>
  12
  13 MODULE_DESCRIPTION("OmniVision ov7640 sensor driver");
  14 MODULE_LICENSE("GPL v2");
  15
  16 static const u8 initial_registers[] = {
  17         0x12, 0x80,
  18         0x12, 0x54,
  19         0x14, 0x24,
  20         0x15, 0x01,
  21         0x28, 0x20,
  22         0x75, 0x82,
  23         0xFF, 0xFF, /* Terminator (reg 0xFF is unused) */
  24 };
  25
  26 static int write_regs(struct i2c_client *client, const u8 *regs)
  27 {
  28         int i;
  29
  30         for (i = 0; regs[i] != 0xFF; i += 2)
  31                 if (i2c_smbus_write_byte_data(client, regs[i], regs[i + 1]) < 0)
  32                         return -1;
  33         return 0;
  34 }
  35
  36 /* ----------------------------------------------------------------------- */
  37
  38 static const struct v4l2_subdev_ops ov7640_ops;
  39
  40 static int ov7640_probe(struct i2c_client *client,
  41                         const struct i2c_device_id *id)
  42 {
  43         struct i2c_adapter *adapter = client->adapter;
  44         struct v4l2_subdev *sd;
  45
  46         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  47                 return -ENODEV;
  48
  49         sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
  50         if (sd == NULL)
  51                 return -ENOMEM;
  52         v4l2_i2c_subdev_init(sd, client, &ov7640_ops);
  53
  54         client->flags = I2C_CLIENT_SCCB;
  55
  56         v4l_info(client, "chip found @ 0x%02x (%s)\n",
  57                         client->addr << 1, client->adapter->name);
  58
  59         if (write_regs(client, initial_registers) < 0) {
  60                 v4l_err(client, "error initializing OV7640\n");
  61                 return -ENODEV;
  62         }
  63
  64         return 0;
  65 }
  66
  67
  68 static int ov7640_remove(struct i2c_client *client)
  69 {
  70         struct v4l2_subdev *sd = i2c_get_clientdata(client);
  71
  72         v4l2_device_unregister_subdev(sd);
  73
  74         return 0;
  75 }
  76
  77 static const struct i2c_device_id ov7640_id[] = {
  78         { "ov7640", 0 },
  79         { }
  80 };
  81 MODULE_DEVICE_TABLE(i2c, ov7640_id);
  82
  83 static struct i2c_driver ov7640_driver = {
  84         .driver = {
  85                 .name   = "ov7640",
  86         },
  87         .probe = ov7640_probe,
  88         .remove = ov7640_remove,
  89         .id_table = ov7640_id,
  90 };
  91 module_i2c_driver(ov7640_driver);