Re: [PATCH v1 08/10] media: i2c: ov772x: Remove soc_camera dependencies

Laurent Pinchart
2017-12-11T14:47:56Z

Hi Jacopo,

Thank you for the patch.

On Wednesday, 15 November 2017 12:56:01 EET Jacopo Mondi wrote:
> Remove soc_camera framework dependencies from ov772x sensor driver.
> - Handle clock directly
> - Register async subdevice
> - Add platform specific enable/disable functions
> - Adjust build system
>
> This commit does not remove the original soc_camera based driver.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
> drivers/media/i2c/Kconfig | 12 +++++++
> drivers/media/i2c/Makefile | 1 +
> drivers/media/i2c/ov772x.c | 88 ++++++++++++++++++++++++++++---------------
> include/media/i2c/ov772x.h | 3 ++
> 4 files changed, 76 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 9415389..ff251ce 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -629,6 +629,18 @@ config VIDEO_OV5670
> To compile this driver as a module, choose M here: the
> module will be called ov5670.
>
> +config VIDEO_OV772X
> + tristate "OmniVision OV772x sensor support"
> + depends on I2C && VIDEO_V4L2
> + depends on MEDIA_CAMERA_SUPPORT
> + ---help---
> + This is a Video4Linux2 sensor-level driver for the OmniVision
> + OV772x camera.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ov772x.
> +
> +

A single blank line is enough.

> config VIDEO_OV7640
> tristate "OmniVision OV7640 sensor support"
> depends on I2C && VIDEO_V4L2
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index f104650..b2459a1 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -66,6 +66,7 @@ obj-$(CONFIG_VIDEO_OV5645) += ov5645.o
> obj-$(CONFIG_VIDEO_OV5647) += ov5647.o
> obj-$(CONFIG_VIDEO_OV5670) += ov5670.o
> obj-$(CONFIG_VIDEO_OV6650) += ov6650.o
> +obj-$(CONFIG_VIDEO_OV772X) += ov772x.o
> obj-$(CONFIG_VIDEO_OV7640) += ov7640.o
> obj-$(CONFIG_VIDEO_OV7670) += ov7670.o
> obj-$(CONFIG_VIDEO_OV9650) += ov9650.o
> diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
> index 8063835..9be7e4e 100644
> --- a/drivers/media/i2c/ov772x.c
> +++ b/drivers/media/i2c/ov772x.c

[snip]

> @@ -650,13 +651,36 @@ static int ov772x_s_register(struct v4l2_subdev *sd,
> }
> #endif
>
> +static int ov772x_power_on(struct ov772x_priv *priv)
> +{
> + int ret;
> +
> + if (priv->info->platform_enable) {
> + ret = priv->info->platform_enable();
> + if (ret)
> + return ret;
> + }
> +
> + /* drivers/sh/clk/core.c returns -EINVAL if clk is NULL */
> + return clk_enable(priv->clk) <= 0 ? 0 : 1;

Then please don't call clk_enable() if priv->clk is NULL, and propagate errors
from clk_enable() back to the caller.

And shouldn't you call clk_prepare_enable() (and clk_disable_unprepare()
below) ?

> +}
> +
> +static int ov772x_power_off(struct ov772x_priv *priv)
> +{
> + if (priv->info->platform_enable)
> + priv->info->platform_disable();
> +
> + clk_disable(priv->clk);
> +
> + return 0;
> +}

[snip]

> @@ -1073,21 +1092,33 @@ static int ov772x_probe(struct i2c_client *client,
> if (priv->hdl.error)
> return priv->hdl.error;
>
> - priv->clk = v4l2_clk_get(&client->dev, "mclk");
> - if (IS_ERR(priv->clk)) {
> + priv->clk = clk_get(&client->dev, "mclk");
> + if (PTR_ERR(priv->clk) == -ENOENT) {
> + priv->clk = NULL;
> + } else if (IS_ERR(priv->clk)) {
> + dev_err(&client->dev, "Unable to get mclk clock\n");
> ret = PTR_ERR(priv->clk);
> - goto eclkget;

You need a priv->clk = NULL here otherwise the error path will oops.

> + goto error_clk_enable;
> }
>
> ret = ov772x_video_probe(priv);
> - if (ret < 0) {
> - v4l2_clk_put(priv->clk);
> -eclkget:
> - v4l2_ctrl_handler_free(&priv->hdl);
> - } else {
> - priv->cfmt = &ov772x_cfmts[0];
> - priv->win = &ov772x_win_sizes[0];
> - }
> + if (ret < 0)
> + goto error_video_probe;
> +
> + priv->cfmt = &ov772x_cfmts[0];
> + priv->win = &ov772x_win_sizes[0];
> +
> + ret = v4l2_async_register_subdev(&priv->subdev);
> + if (ret)
> + goto error_video_probe;
> +
> + return 0;
> +
> +error_video_probe:
> + if (priv->clk)
> + clk_put(priv->clk);

clk_put() accepts a NULL clock, you don't have to check the pointer first.

> +error_clk_enable:
> + v4l2_ctrl_handler_free(&priv->hdl);
>
> return ret;
> }
> @@ -1096,7 +1127,8 @@ static int ov772x_remove(struct i2c_client *client)
> {
> struct ov772x_priv *priv = to_ov772x(i2c_get_clientdata(client));
>
> - v4l2_clk_put(priv->clk);
> + if (priv->clk)
> + clk_put(priv->clk);

Same here.

> v4l2_device_unregister_subdev(&priv->subdev);
> v4l2_ctrl_handler_free(&priv->hdl);
> return 0;
> diff --git a/include/media/i2c/ov772x.h b/include/media/i2c/ov772x.h
> index 00dbb7c..5896dff 100644
> --- a/include/media/i2c/ov772x.h
> +++ b/include/media/i2c/ov772x.h
> @@ -54,6 +54,9 @@ struct ov772x_edge_ctrl {
> struct ov772x_camera_info {
> unsigned long flags;
> struct ov772x_edge_ctrl edgectrl;
> +
> + int (*platform_enable)(void);
> + void (*platform_disable)(void);
> };
>
> #endif /* __OV772X_H__ */

--
Regards,

Laurent Pinchart