Re: [V7, 2/2] media: i2c: dw9768: Add DW9768 VCM driver

[Dongchun Zhu <dongchun.zhu@mediatek.com>]

Hi Sakari,

Thanks for the timely review.

On Fri, 2020-06-05 at 15:14 +0300, Sakari Ailus wrote:
> Hi Dongchun,
> 
> Thank you for the update.
> 
> On Fri, Jun 05, 2020 at 06:54:12PM +0800, Dongchun Zhu wrote:
> > Add a V4L2 sub-device driver for DW9768 voice coil motor, providing
> > control to set the desired focus via IIC serial interface.
> > 
> > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > ---
> >  MAINTAINERS                |   1 +
> >  drivers/media/i2c/Kconfig  |  13 ++
> >  drivers/media/i2c/Makefile |   1 +
> >  drivers/media/i2c/dw9768.c | 566 +++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 581 insertions(+)
> >  create mode 100644 drivers/media/i2c/dw9768.c
> > 

[snip]...

> > +
> > +static int dw9768_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct dw9768 *dw9768;
> > +	u32 aac_mode_select;
> > +	u32 aac_timing_select;
> > +	u32 clock_presc_select;
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	dw9768 = devm_kzalloc(dev, sizeof(*dw9768), GFP_KERNEL);
> > +	if (!dw9768)
> > +		return -ENOMEM;
> > +
> > +	/* Initialize subdev */
> > +	v4l2_i2c_subdev_init(&dw9768->sd, client, &dw9768_ops);
> > +
> > +	dw9768->aac_mode = DW9768_AAC_MODE_DEFAULT;
> > +	dw9768->aac_timing = DW9768_AAC_TIME_DEFAULT;
> > +	dw9768->clock_presc = DW9768_CLOCK_PRE_SCALE_DEFAULT;
> > +
> > +	/* Optional indication of AAC mode select */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "dongwoon,aac-mode",
> > +				       &aac_mode_select);
> > +
> > +	if (!ret)
> > +		dw9768->aac_mode = aac_mode_select;
> > +
> > +	/* Optional indication of clock pre-scale select */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "dongwoon,clock-presc",
> > +				       &clock_presc_select);
> > +
> > +	if (!ret)
> > +		dw9768->clock_presc = clock_presc_select;
> > +
> > +	/* Optional indication of AAC Timing */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "dongwoon,aac-timing",
> > +				       &aac_timing_select);
> > +
> > +	if (!ret)
> > +		dw9768->aac_timing = aac_timing_select;
> 
> You can assign the defaults to the dw9768 struct and use the fwnode
> property API to read the properties into the same fields. No return values
> need to be checked.
> 

Good idea :-)

> > +
> > +	for (i = 0; i < ARRAY_SIZE(dw9768_supply_names); i++)
> > +		dw9768->supplies[i].supply = dw9768_supply_names[i];
> > +
> > +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dw9768_supply_names),
> > +				      dw9768->supplies);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get regulators\n");
> > +		return ret;
> > +	}
> > +
> > +	/* Initialize controls */
> > +	ret = dw9768_init_controls(dw9768);
> > +	if (ret)
> > +		goto err_free_handler;
> > +
> > +	/* Initialize subdev */
> > +	dw9768->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	dw9768->sd.internal_ops = &dw9768_int_ops;
> > +
> > +	ret = media_entity_pads_init(&dw9768->sd.entity, 0, NULL);
> > +	if (ret < 0)
> > +		goto err_free_handler;
> > +
> > +	dw9768->sd.entity.function = MEDIA_ENT_F_LENS;
> > +
> > +	pm_runtime_enable(dev);
> > +	if (!pm_runtime_enabled(dev)) {
> > +		ret = dw9768_runtime_resume(dev);
> > +		if (ret < 0) {
> > +			dev_err(dev, "failed to power on: %d\n", ret);
> > +			goto err_clean_entity;
> > +		}
> > +	}
> > +
> > +	ret = v4l2_async_register_subdev(&dw9768->sd);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > +		goto error_async_register;
> > +	}
> > +
> > +	return 0;
> > +
> > +error_async_register:
> > +	if (!pm_runtime_enabled(dev))
> > +		dw9768_runtime_suspend(dev);
> > +err_clean_entity:
> > +	media_entity_cleanup(&dw9768->sd.entity);
> > +err_free_handler:
> > +	v4l2_ctrl_handler_free(&dw9768->ctrls);
> > +
> > +	return ret;
> > +}
> > +

[snip]...