Hi Sakari
On Mon, 20 Jan 2025 at 10:59, Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote:
>
> Hi Dave,
>
> On Fri, Jan 10, 2020 at 11:09:15PM +0300, Andrey Konovalov wrote:
> > +/* Power/clock management functions */
> > +static int imx219_power_on(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct imx219 *imx219 = to_imx219(sd);
> > + int ret;
> > +
> > + ret = regulator_bulk_enable(IMX219_NUM_SUPPLIES,
> > + imx219->supplies);
> > + if (ret) {
> > + dev_err(&client->dev, "%s: failed to enable regulators\n",
> > + __func__);
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(imx219->xclk);
> > + if (ret) {
> > + dev_err(&client->dev, "%s: failed to enable clock\n",
> > + __func__);
> > + goto reg_off;
> > + }
> > +
> > + gpiod_set_value_cansleep(imx219->reset_gpio, 1);
> > + msleep(IMX219_XCLR_DELAY_MS);
> > +
> > + return 0;
> > +reg_off:
> > + regulator_bulk_disable(IMX219_NUM_SUPPLIES, imx219->supplies);
> > + return ret;
> > +}
> > +
> > +static int imx219_power_off(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > + struct imx219 *imx219 = to_imx219(sd);
> > +
> > + gpiod_set_value_cansleep(imx219->reset_gpio, 0);
>
> The polarity of the reset GPIO appears to be wrong above. Given it works
> somewhere (arch/arm64/boot/dts/ti/k3-am62x-sk-csi2-imx219.dtso), the
> existing DTS files have it wrong, too. The bindings still appear to
> document it correctly.
Why do you say it is wrong?
I don't recall why this got called reset-gpio - the signal on the
sensor is XCLR, and that is documented in the binding.
The datasheet says low is standby and high is active, which matches
what the driver does.
> Laurent confirmed xcrl isn't controllable in the RPi imx219 camera module.
>
> How about fixing this? Currently correctly written DTBs including imx219
> won't work.
Seeing as the DTB is ABI, the only improvement I can see is to rename
"imx219->reset_gpio" to "imx219->xclr_gpio".
What else would you be proposing?
Dave
> I noticed this while fixing the power sequences in this and a few other
> drivers.
>
> > + regulator_bulk_disable(IMX219_NUM_SUPPLIES, imx219->supplies);
> > + clk_disable_unprepare(imx219->xclk);
> > +
> > + return 0;
> > +}
>
> ...
>
> > +static int imx219_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + struct device *dev = &client->dev;
> > + struct fwnode_handle *endpoint;
> > + struct imx219 *imx219;
> > + int ret;
> > +
> > + imx219 = devm_kzalloc(&client->dev, sizeof(*imx219), GFP_KERNEL);
> > + if (!imx219)
> > + return -ENOMEM;
> > +
> > + imx219->dev = dev;
> > +
> > + v4l2_i2c_subdev_init(&imx219->sd, client, &imx219_subdev_ops);
> > +
> > + /* Get CSI2 bus config */
> > + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev),
> > + NULL);
> > + if (!endpoint) {
> > + dev_err(dev, "endpoint node not found\n");
> > + return -EINVAL;
> > + }
> > +
> > + ret = v4l2_fwnode_endpoint_parse(endpoint, &imx219->ep);
> > + fwnode_handle_put(endpoint);
> > + if (ret) {
> > + dev_err(dev, "could not parse endpoint\n");
> > + return ret;
> > + }
> > +
> > + /* Check the number of MIPI CSI2 data lanes */
> > + if (imx219->ep.bus_type != V4L2_MBUS_CSI2_DPHY ||
> > + imx219->ep.bus.mipi_csi2.num_data_lanes != 2) {
> > + dev_err(dev, "only 2 data lanes are currently supported\n");
> > + return -EINVAL;
> > + }
> > +
> > + /* Get system clock (xclk) */
> > + imx219->xclk = devm_clk_get(dev, NULL);
> > + if (IS_ERR(imx219->xclk)) {
> > + dev_err(dev, "failed to get xclk\n");
> > + return PTR_ERR(imx219->xclk);
> > + }
> > +
> > + imx219->xclk_freq = clk_get_rate(imx219->xclk);
> > + if (imx219->xclk_freq != IMX219_XCLK_FREQ) {
> > + dev_err(dev, "xclk frequency not supported: %d Hz\n",
> > + imx219->xclk_freq);
> > + return -EINVAL;
> > + }
> > +
> > + ret = imx219_get_regulators(imx219);
> > + if (ret) {
> > + dev_err(dev, "failed to get regulators\n");
> > + return ret;
> > + }
> > +
> > + /* Request optional enable pin */
> > + imx219->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > + GPIOD_OUT_HIGH);
> > +
> > + /*
> > + * The sensor must be powered for imx219_identify_module()
> > + * to be able to read the CHIP_ID register
> > + */
> > + ret = imx219_power_on(dev);
> > + if (ret)
> > + return ret;
> > +
> > + ret = imx219_identify_module(imx219);
> > + if (ret)
> > + goto error_power_off;
> > +
> > + /* Set default mode to max resolution */
> > + imx219->mode = &supported_modes[0];
> > +
> > + ret = imx219_init_controls(imx219);
> > + if (ret)
> > + goto error_power_off;
> > +
> > + /* Initialize subdev */
> > + imx219->sd.internal_ops = &imx219_internal_ops;
> > + imx219->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > + imx219->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +
> > + /* Initialize source pad */
> > + imx219->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +
> > + ret = media_entity_pads_init(&imx219->sd.entity, 1, &imx219->pad);
> > + if (ret) {
> > + dev_err(dev, "failed to init entity pads: %d\n", ret);
> > + goto error_handler_free;
> > + }
> > +
> > + ret = v4l2_async_register_subdev_sensor_common(&imx219->sd);
> > + if (ret < 0) {
> > + dev_err(dev, "failed to register sensor sub-device: %d\n", ret);
> > + goto error_media_entity;
> > + }
> > +
> > + /* Enable runtime PM and turn off the device */
> > + pm_runtime_set_active(dev);
> > + pm_runtime_enable(dev);
> > + pm_runtime_idle(dev);
> > +
> > + return 0;
> > +
> > +error_media_entity:
> > + media_entity_cleanup(&imx219->sd.entity);
> > +
> > +error_handler_free:
> > + imx219_free_controls(imx219);
> > +
> > +error_power_off:
> > + imx219_power_off(dev);
> > +
> > + return ret;
> > +}
>
> --
> Kind regards,
>
> Sakari Ailus
