Hi Josh,
Thank you for the patch.
On Monday 08 December 2014 19:29:05 Josh Wu wrote:
> Add device tree support for ov2640.
>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
> ---
> v1 -> v2:
> 1. use gpiod APIs.
> 2. change the gpio pin's name according to datasheet.
> 3. reduce the delay for .reset() function.
>
> drivers/media/i2c/soc_camera/ov2640.c | 86 +++++++++++++++++++++++++++++---
> 1 file changed, 80 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/i2c/soc_camera/ov2640.c
> b/drivers/media/i2c/soc_camera/ov2640.c index 9ee910d..2a57979 100644
> --- a/drivers/media/i2c/soc_camera/ov2640.c
> +++ b/drivers/media/i2c/soc_camera/ov2640.c
> @@ -18,6 +18,8 @@
> #include <linux/i2c.h>
> #include <linux/slab.h>
> #include <linux/delay.h>
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> #include <linux/v4l2-mediabus.h>
> #include <linux/videodev2.h>
>
> @@ -283,6 +285,10 @@ struct ov2640_priv {
> u32 cfmt_code;
> struct v4l2_clk *clk;
> const struct ov2640_win_size *win;
> +
> + struct soc_camera_subdev_desc ssdd_dt;
> + struct gpio_desc *resetb_gpio;
> + struct gpio_desc *pwdn_gpio;
> };
>
> /*
> @@ -1047,6 +1053,61 @@ static struct v4l2_subdev_ops ov2640_subdev_ops = {
> .video = &ov2640_subdev_video_ops,
> };
>
> +/* OF probe functions */
> +static int ov2640_hw_power(struct device *dev, int on)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct ov2640_priv *priv = to_ov2640(client);
> +
> + dev_dbg(&client->dev, "%s: %s the camera\n",
> + __func__, on ? "ENABLE" : "DISABLE");
> +
> + if (priv->pwdn_gpio && !IS_ERR(priv->pwdn_gpio))
No need to test for IS_ERR, as the probe function would have failed in that
case.
> + gpiod_direction_output(priv->pwdn_gpio, !on);
> +
> + return 0;
> +}
> +
> +static int ov2640_hw_reset(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct ov2640_priv *priv = to_ov2640(client);
> +
> + /* If enabled, give a reset impulse */
> + if (priv->resetb_gpio && !IS_ERR(priv->resetb_gpio)) {
Same here.
> + gpiod_direction_output(priv->resetb_gpio, 0);
Given that your DT should specify the active low GPIO flag, and that the gpiod
API inverts the value in that case, you should set the value to 1 here.
> + usleep_range(3000, 5000);
> + gpiod_direction_output(priv->resetb_gpio, 1);
And to 0 here.
> + }
> +
> + return 0;
> +}
> +
> +static int ov2640_probe_dt(struct i2c_client *client,
> + struct ov2640_priv *priv)
> +{
> + priv->resetb_gpio = devm_gpiod_get_optional(&client->dev, "resetb",
> + GPIOD_OUT_HIGH);
> + if (!priv->resetb_gpio)
> + dev_warn(&client->dev, "resetb gpio not found!\n");
No need to warn here, it's perfectly fine if the reset signal isn't connected
to a GPIO.
> + else if (IS_ERR(priv->resetb_gpio))
> + return -EINVAL;
> +
> + priv->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "pwdn",
> + GPIOD_OUT_HIGH);
> + if (!priv->pwdn_gpio)
> + dev_warn(&client->dev, "pwdn gpio not found!\n");
Same here.
> + else if (IS_ERR(priv->pwdn_gpio))
> + return -EINVAL;
> +
> + /* Initialize the soc_camera_subdev_desc */
> + priv->ssdd_dt.power = ov2640_hw_power;
> + priv->ssdd_dt.reset = ov2640_hw_reset;
> + client->dev.platform_data = &priv->ssdd_dt;
> +
> + return 0;
> +}
> +
> /*
> * i2c_driver functions
> */
> @@ -1058,12 +1119,6 @@ static int ov2640_probe(struct i2c_client *client,
> struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> int ret;
>
> - if (!ssdd) {
> - dev_err(&adapter->dev,
> - "OV2640: Missing platform_data for driver\n");
> - return -EINVAL;
> - }
> -
> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
> dev_err(&adapter->dev,
> "OV2640: I2C-Adapter doesn't support SMBUS\n");
> @@ -1077,6 +1132,18 @@ static int ov2640_probe(struct i2c_client *client,
> return -ENOMEM;
> }
>
> + if (!ssdd) {
> + if (client->dev.of_node) {
> + ret = ov2640_probe_dt(client, priv);
> + if (ret)
> + return ret;
> + } else {
> + dev_err(&client->dev,
> + "Missing platform_data for driver\n");
> + return -EINVAL;
> + }
I would test for !client->dev.of_node and return the error, you could then get
rid of the else and lower the indentation level for the call to
ov2640_probe_dt().
> + }
> +
> v4l2_i2c_subdev_init(&priv->subdev, client, &ov2640_subdev_ops);
> v4l2_ctrl_handler_init(&priv->hdl, 2);
> v4l2_ctrl_new_std(&priv->hdl, &ov2640_ctrl_ops,
> @@ -1123,9 +1190,16 @@ static const struct i2c_device_id ov2640_id[] = {
> };
> MODULE_DEVICE_TABLE(i2c, ov2640_id);
>
> +static const struct of_device_id ov2640_of_match[] = {
> + {.compatible = "ovti,ov2640", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, ov2640_of_match);
> +
> static struct i2c_driver ov2640_i2c_driver = {
> .driver = {
> .name = "ov2640",
> + .of_match_table = of_match_ptr(ov2640_of_match),
> },
> .probe = ov2640_probe,
> .remove = ov2640_remove,
--
Regards,
Laurent Pinchart
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