// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <linux/slab.h>

MODULE_DESCRIPTION("OmniVision ov7640 sensor driver");
MODULE_LICENSE("GPL v2");

struct reg_val {
        u8 reg;
        u8 val;
};

static const struct reg_val regval_init[] = {
        {0x12, 0x80},
        {0x12, 0x54},
        {0x14, 0x24},
        {0x15, 0x01},
        {0x28, 0x20},
        {0x75, 0x82},
};

static int write_regs(struct i2c_client *client,
                const struct reg_val *rv, int len)
{
        while (--len >= 0) {
                if (i2c_smbus_write_byte_data(client, rv->reg, rv->val) < 0)
                        return -1;
                rv++;
        }
        return 0;
}

/* ----------------------------------------------------------------------- */

static const struct v4l2_subdev_ops ov7640_ops;

static int ov7640_probe(struct i2c_client *client)
{
        struct i2c_adapter *adapter = client->adapter;
        struct v4l2_subdev *sd;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
        if (sd == NULL)
                return -ENOMEM;
        v4l2_i2c_subdev_init(sd, client, &ov7640_ops);

        client->flags = I2C_CLIENT_SCCB;

        v4l_info(client, "chip found @ 0x%02x (%s)\n",
                        client->addr << 1, client->adapter->name);

        if (write_regs(client, regval_init, ARRAY_SIZE(regval_init)) < 0) {
                v4l_err(client, "error initializing OV7640\n");
                return -ENODEV;
        }

        return 0;
}


static void ov7640_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);

        v4l2_device_unregister_subdev(sd);
}

static const struct i2c_device_id ov7640_id[] = {
        { "ov7640" },
        { }
};
MODULE_DEVICE_TABLE(i2c, ov7640_id);

static struct i2c_driver ov7640_driver = {
        .driver = {
                .name   = "ov7640",
        },
        .probe = ov7640_probe,
        .remove = ov7640_remove,
        .id_table = ov7640_id,
};
module_i2c_driver(ov7640_driver);