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

Laurent Pinchart
2022-11-23T10:32:38Z

Hi Alexander,

On Wed, Nov 23, 2022 at 09:14:34AM +0100, Alexander Stein wrote:
> 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.

Oops. I'll fix that.

> > + 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.

It's done later in the series :-)

> > }
> >
> > 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.
>
> > }
> >
> > 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;
> > }