Hi Jacopo,
Thank you for the patch.
On Mon, Mar 14, 2022 at 05:27:09PM +0100, Jacopo Mondi wrote:
> Add support for probing the main system clock using the common clock
> framework and its OF bindings.
>
> Maintain ACPI compatibility by falling back to parse 'clock-frequency'
> if the no clock device reference is available.
>
> Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> ---
> drivers/media/i2c/ov5670.c | 21 +++++++++++++++++----
> 1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
> index 721441024598..25d792794fc7 100644
> --- a/drivers/media/i2c/ov5670.c
> +++ b/drivers/media/i2c/ov5670.c
> @@ -2,6 +2,7 @@
> // Copyright (c) 2017 Intel Corporation.
>
> #include <linux/acpi.h>
> +#include <linux/clk.h>
> #include <linux/i2c.h>
> #include <linux/mod_devicetable.h>
> #include <linux/module.h>
> @@ -1819,6 +1820,8 @@ struct ov5670 {
> struct v4l2_subdev sd;
> struct media_pad pad;
>
> + struct clk *clk;
> +
> struct v4l2_ctrl_handler ctrl_handler;
> /* V4L2 Controls */
> struct v4l2_ctrl *link_freq;
> @@ -2478,10 +2481,6 @@ static int ov5670_probe(struct i2c_client *client)
> bool full_power;
> int ret;
>
> - device_property_read_u32(&client->dev, "clock-frequency", &input_clk);
> - if (input_clk != 19200000)
> - return -EINVAL;
> -
> ov5670 = devm_kzalloc(&client->dev, sizeof(*ov5670), GFP_KERNEL);
> if (!ov5670) {
> ret = -ENOMEM;
> @@ -2489,6 +2488,20 @@ static int ov5670_probe(struct i2c_client *client)
> goto error_print;
> }
>
> + /* OF uses the common clock framework, ACPI uses "clock-frequency". */
> + ov5670->clk = devm_clk_get_optional(&client->dev, NULL);
> + if (IS_ERR(ov5670->clk))
> + return dev_err_probe(&client->dev, PTR_ERR(ov5670->clk),
> + "error getting clock\n");
> +
> + if (ov5670->clk)
> + input_clk = clk_get_rate(ov5670->clk);
> + else
> + device_property_read_u32(&client->dev, "clock-frequency",
> + &input_clk);
This will try to use the clock-frequency property on OF-based systems if
no clock is specified. Could we instead have
if (probed through OF) {
use clock
} else {
use clock-frequency
}
?
> + if (input_clk != 19200000)
> + return -EINVAL;
> +
> /* Initialize subdev */
> v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);
>
--
Regards,
Laurent Pinchart
