Re: [PATCH v1 08/15] media: i2c: imx290: Factor out DT parsing to separate function

Alexander Stein
2022-11-23T08:14:38Z

Hello Laurent,

thanks for working on this.

Am Dienstag, 22. November 2022, 23:32:43 CET schrieb Laurent Pinchart:
> Make the probe() function more readable by factoring out the DT parsing
> code to a separate function. No functional change intended.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> drivers/media/i2c/imx290.c | 97 +++++++++++++++++++++-----------------
> 1 file changed, 53 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
> index d9fc6c44b0f0..655f676df3d2 100644
> --- a/drivers/media/i2c/imx290.c
> +++ b/drivers/media/i2c/imx290.c
> @@ -1139,112 +1139,125 @@ static s64 imx290_check_link_freqs(const struct
> imx290 *imx290, return 0;
> }
>
> -static int imx290_probe(struct i2c_client *client)
> +static int imx290_parse_dt(struct imx290 *imx290)
> {
> - struct device *dev = &client->dev;
> - struct fwnode_handle *endpoint;
> /* Only CSI2 is supported for now: */
> struct v4l2_fwnode_endpoint ep = {
> .bus_type = V4L2_MBUS_CSI2_DPHY
> };
> - struct imx290 *imx290;
> - u32 xclk_freq;
> - u32 chip_id;

I assume your patch for reading the chip ID slipped into this series.
Either add it to the series or rearrange your patches.

> + struct fwnode_handle *endpoint;
> + int ret;
> s64 fq;
> - int ret;
>
> - imx290 = devm_kzalloc(dev, sizeof(*imx290), GFP_KERNEL);
> - if (!imx290)
> - return -ENOMEM;
> -
> - imx290->dev = dev;
> - imx290->regmap = devm_regmap_init_i2c(client,
&imx290_regmap_config);
> - if (IS_ERR(imx290->regmap)) {
> - dev_err(dev, "Unable to initialize I2C\n");
> - return -ENODEV;
> - }
> -
> - endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
> + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(imx290->dev),
NULL);
> if (!endpoint) {
> - dev_err(dev, "Endpoint node not found\n");
> + dev_err(imx290->dev, "Endpoint node not found\n");
> return -EINVAL;
> }
>
> ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
> fwnode_handle_put(endpoint);
> if (ret == -ENXIO) {
> - dev_err(dev, "Unsupported bus type, should be CSI2\n");
> - goto err_endpoint;
> + dev_err(imx290->dev, "Unsupported bus type, should be
CSI2\n");
> + goto done;
> } else if (ret) {
> - dev_err(dev, "Parsing endpoint node failed\n");
> - goto err_endpoint;
> + dev_err(imx290->dev, "Parsing endpoint node failed\n");
> + goto done;
> }
>
> /* Get number of data lanes */
> imx290->nlanes = ep.bus.mipi_csi2.num_data_lanes;
> if (imx290->nlanes != 2 && imx290->nlanes != 4) {
> - dev_err(dev, "Invalid data lanes: %d\n", imx290->nlanes);
> + dev_err(imx290->dev, "Invalid data lanes: %d\n", imx290-
>nlanes);
> ret = -EINVAL;
> - goto err_endpoint;
> + goto done;
> }
>
> - dev_dbg(dev, "Using %u data lanes\n", imx290->nlanes);
> + dev_dbg(imx290->dev, "Using %u data lanes\n", imx290->nlanes);
>
> if (!ep.nr_of_link_frequencies) {
> - dev_err(dev, "link-frequency property not found in DT\n");
> + dev_err(imx290->dev, "link-frequency property not found in
DT\n");
> ret = -EINVAL;
> - goto err_endpoint;
> + goto done;
> }
>
> /* Check that link frequences for all the modes are in device tree
*/
> fq = imx290_check_link_freqs(imx290, &ep);
> if (fq) {
> - dev_err(dev, "Link frequency of %lld is not supported\n",
fq);
> + dev_err(imx290->dev, "Link frequency of %lld is not
supported\n",
> + fq);
> ret = -EINVAL;
> - goto err_endpoint;
> + goto done;
> }
>
> + ret = 0;
> +
> +done:
> + v4l2_fwnode_endpoint_free(&ep);
> + return ret;
> +}
> +
> +static int imx290_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct imx290 *imx290;
> + u32 xclk_freq;
> + u32 chip_id;
> + int ret;
> +
> + imx290 = devm_kzalloc(dev, sizeof(*imx290), GFP_KERNEL);
> + if (!imx290)
> + return -ENOMEM;
> +
> + imx290->dev = dev;
> + imx290->regmap = devm_regmap_init_i2c(client,
&imx290_regmap_config);
> + if (IS_ERR(imx290->regmap)) {
> + dev_err(dev, "Unable to initialize I2C\n");
> + return -ENODEV;
> + }
> +
> + ret = imx290_parse_dt(imx290);
> + if (ret)
> + return ret;
> +
> /* get system clock (xclk) */
> imx290->xclk = devm_clk_get(dev, "xclk");
> if (IS_ERR(imx290->xclk)) {
> dev_err(dev, "Could not get xclk");
> - ret = PTR_ERR(imx290->xclk);
> - goto err_endpoint;
> + return PTR_ERR(imx290->xclk);

Mh, using dev_err_probe this can be a one-liner.

> }
>
> ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> &xclk_freq);
> if (ret) {
> dev_err(dev, "Could not get xclk frequency\n");
> - goto err_endpoint;
> + return ret;
> }
>
> /* external clock must be 37.125 MHz */
> if (xclk_freq != 37125000) {
> dev_err(dev, "External clock frequency %u is not
supported\n",
> xclk_freq);
> - ret = -EINVAL;
> - goto err_endpoint;
> + return -EINVAL;
> }
>
> ret = clk_set_rate(imx290->xclk, xclk_freq);
> if (ret) {
> dev_err(dev, "Could not set xclk frequency\n");
> - goto err_endpoint;
> + return ret;
> }
>
> ret = imx290_get_regulators(dev, imx290);
> if (ret < 0) {
> dev_err(dev, "Cannot get regulators\n");
> - goto err_endpoint;
> + return ret;

Using dev_err_probe this can be a one-liner as well.

> }
>
> imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset",
>
GPIOD_OUT_HIGH);
> if (IS_ERR(imx290->rst_gpio)) {
> dev_err(dev, "Cannot get reset gpio\n");
> - ret = PTR_ERR(imx290->rst_gpio);
> - goto err_endpoint;
> + return PTR_ERR(imx290->rst_gpio);

Using dev_err_probe this can be a one-liner as well.

Regards,
Alexander

> }
>
> mutex_init(&imx290->lock);
> @@ -1279,16 +1292,12 @@ static int imx290_probe(struct i2c_client *client)
> pm_runtime_enable(dev);
> pm_runtime_idle(dev);
>
> - v4l2_fwnode_endpoint_free(&ep);
> -
> return 0;
>
> err_subdev:
> imx290_subdev_cleanup(imx290);
> err_mutex:
> mutex_destroy(&imx290->lock);
> -err_endpoint:
> - v4l2_fwnode_endpoint_free(&ep);
>
> return ret;
> }