Re: [V9, 2/2] media: i2c: ov02a10: Add OV02A10 image sensor driver

[Tomasz Figa <tfiga@chromium.org>]

On Thu, Jun 4, 2020 at 11:26 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Dongchun,
>
> On Thu, Jun 04, 2020 at 10:14:05AM +0800, Dongchun Zhu wrote:
> > Hi Tomasz, Sakari, and sirs,
> >
> > Could anyone help to review this patch?
> >
> > On Sat, 2020-05-23 at 16:41 +0800, Dongchun Zhu wrote:
> > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > >
> > > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > > ---
> > >  MAINTAINERS                 |    1 +
> > >  drivers/media/i2c/Kconfig   |   13 +
> > >  drivers/media/i2c/Makefile  |    1 +
> > >  drivers/media/i2c/ov02a10.c | 1025 +++++++++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 1040 insertions(+)
> > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > >
> >
> > [snip]
> >
> > > +static int ov02a10_probe(struct i2c_client *client)
> > > +{
> > > +   struct device *dev = &client->dev;
> > > +   struct ov02a10 *ov02a10;
> > > +   unsigned int rotation;
> > > +   unsigned int clock_lane_tx_speed;
> > > +   unsigned int i;
> > > +   int ret;
> > > +
> > > +   ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> > > +   if (!ov02a10)
> > > +           return -ENOMEM;
> > > +
> > > +   ret = ov02a10_check_hwcfg(dev, ov02a10);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to check HW configuration: %d", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > > +   ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> > > +   ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> > > +
> > > +   /* Optional indication of physical rotation of sensor */
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > > +   if (!ret && rotation == 180) {
> > > +           ov02a10->upside_down = true;
> > > +           ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > > +   }
> > > +
> > > +   /* Optional indication of mipi TX speed */
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> > > +                                  &clock_lane_tx_speed);
> > > +
> > > +   if (!ret)
> > > +           ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> > > +
> > > +   /* Get system clock (eclk) */
> > > +   ov02a10->eclk = devm_clk_get(dev, "eclk");
> > > +   if (IS_ERR(ov02a10->eclk)) {
> > > +           ret = PTR_ERR(ov02a10->eclk);
> > > +           dev_err(dev, "failed to get eclk %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > > +                                  &ov02a10->eclk_freq);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to get eclk frequency\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> > > +           dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> > > +                    ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> > > +           return -EINVAL;
> > > +   }
> > > +
> > > +   ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> > > +   if (IS_ERR(ov02a10->pd_gpio)) {
> > > +           ret = PTR_ERR(ov02a10->pd_gpio);
> > > +           dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   ov02a10->n_rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > > +   if (IS_ERR(ov02a10->n_rst_gpio)) {
> > > +           ret = PTR_ERR(ov02a10->n_rst_gpio);
> > > +           dev_err(dev, "failed to get reset-gpios %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> > > +           ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> > > +
> > > +   ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> > > +                                 ov02a10->supplies);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to get regulators\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   mutex_init(&ov02a10->mutex);
> > > +   ov02a10->cur_mode = &supported_modes[0];
> > > +   ret = ov02a10_initialize_controls(ov02a10);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to initialize controls\n");
> > > +           goto err_destroy_mutex;
> > > +   }
> > > +
> > > +   ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > +   ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> > > +   ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > > +   ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> > > +   ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> > > +   if (ret < 0) {
> > > +           dev_err(dev, "failed to init entity pads: %d", ret);
> > > +           goto err_free_handler;
> > > +   }
> > > +
> > > +   pm_runtime_enable(dev);
> > > +   if (!pm_runtime_enabled(dev)) {
> > > +           ret = ov02a10_power_on(dev);
> > > +           if (ret < 0) {
> > > +                   dev_err(dev, "failed to power on: %d\n", ret);
> > > +                   goto err_free_handler;
> > > +           }
> > > +   }
> > > +
> > > +   ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > > +           if (!pm_runtime_enabled(dev))
> > > +                   ov02a10_power_off(dev);
>
> This should be moved to error handling section below.
>
> > > +           goto err_clean_entity;
> > > +   }
> >
> > Tomasz, Sakari, is this ok?
> > or coding like this:
> >
> > ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > if (!pm_runtime_enabled(dev))
> >       ov02a10_power_off(dev);
> > if (ret) {
> >       dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> >       goto err_clean_entity;
> > }
> >
> > What's your opinions about the change?
>
> This turns power off if runtime PM is disabled. I'd keep it as-is, as it'd
> require re-implementing what runtime PM is used for now --- and that's not
> a sensor driver's job.

That and in general I believe the expectations are:

- runtime PM enabled - powered on only when it has something to do
- runtime PM disabled - powered on when the driver is bound (probe
succeeded), powered off when the driver unbinds (remove or probe
error)

Best regards,
Tomasz

>
> >
> > > +
> > > +   return 0;
> > > +
> > > +err_clean_entity:
> > > +   media_entity_cleanup(&ov02a10->subdev.entity);
> > > +err_free_handler:
> > > +   v4l2_ctrl_handler_free(ov02a10->subdev.ctrl_handler);
> > > +err_destroy_mutex:
> > > +   mutex_destroy(&ov02a10->mutex);
> > > +
> > > +   return ret;
> > > +}
> > > +
> > > +static int ov02a10_remove(struct i2c_client *client)
> > > +{
> > > +   struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > > +   struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > > +
> > > +   v4l2_async_unregister_subdev(sd);
> > > +   media_entity_cleanup(&sd->entity);
> > > +   v4l2_ctrl_handler_free(sd->ctrl_handler);
> > > +   pm_runtime_disable(&client->dev);
> > > +   if (!pm_runtime_status_suspended(&client->dev))
> > > +           ov02a10_power_off(&client->dev);
> > > +   pm_runtime_set_suspended(&client->dev);
> > > +   mutex_destroy(&ov02a10->mutex);
> > > +
> > > +   return 0;
> > > +}
> > > +
> > > +static const struct of_device_id ov02a10_of_match[] = {
> > > +   { .compatible = "ovti,ov02a10" },
> > > +   {}
> > > +};
> > > +MODULE_DEVICE_TABLE(of, ov02a10_of_match);
> > > +
> > > +static struct i2c_driver ov02a10_i2c_driver = {
> > > +   .driver = {
> > > +           .name = "ov02a10",
> > > +           .pm = &ov02a10_pm_ops,
> > > +           .of_match_table = ov02a10_of_match,
> > > +   },
> > > +   .probe_new      = &ov02a10_probe,
> > > +   .remove         = &ov02a10_remove,
> > > +};
> > > +
> > > +module_i2c_driver(ov02a10_i2c_driver);
> > > +
> > > +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> > > +MODULE_DESCRIPTION("OmniVision OV02A10 sensor driver");
> > > +MODULE_LICENSE("GPL v2");
> > > +
> >
>
> --
> Sakari Ailus