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

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

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;
> >  }

-- 
Regards,

Laurent Pinchart