Re: [PATCH v15 2/2] media: i2c: Add OV02A10 image sensor driver

Dongchun Zhu
2020-11-19T13:07:13Z

Hi Andy,

On Fri, 2020-10-23 at 17:31 +0300, Andy Shevchenko wrote:
> On Tue, Oct 13, 2020 at 09:05:03PM +0800, Dongchun Zhu wrote:
> > Add a V4L2 sub-device driver for OmniVision OV02A10 image sensor.
>
> ...
>
> > +#define OV02A10_ID_MASK 0xffff
>
> GENMASK()
>
> (And include bits.h for that)
>

It seems could build pass without including bits.h, as DW9768 once used.

> ...
>
> > +static int __ov02a10_start_stream(struct ov02a10 *ov02a10)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
> > + const struct ov02a10_reg_list *reg_list;
> > + int ret;
> > +
> > + /* Apply default values of current mode */
> > + reg_list = &ov02a10->cur_mode->reg_list;
> > + ret = ov02a10_write_array(ov02a10, reg_list);
> > + if (ret)
> > + return ret;
> > +
> > + /* Apply customized values from user */
> > + ret = __v4l2_ctrl_handler_setup(ov02a10->subdev.ctrl_handler);
> > + if (ret)
> > + return ret;
> > +
> > + /* Set orientation to 180 degree */
> > + if (ov02a10->upside_down) {
> > + ret = i2c_smbus_write_byte_data(client, REG_MIRROR_FLIP_CONTROL,
> > + REG_MIRROR_FLIP_ENABLE);
> > + if (ret) {
>
> Shouldn't you use 'ret < 0' here as well?
>

Fixed in next release.

> > + dev_err(&client->dev, "failed to set orientation\n");
> > + return ret;
> > + }
> > + ret = i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
> > + REG_ENABLE);
> > + if (ret < 0)
> > + return ret;
> > + }
> > +
> > + /* Set MIPI TX speed according to DT property */
> > + if (ov02a10->mipi_clock_voltage != OV02A10_MIPI_TX_SPEED_DEFAULT) {
> > + ret = i2c_smbus_write_byte_data(client, TX_SPEED_AREA_SEL,
> > + ov02a10->mipi_clock_voltage);
> > + if (ret < 0)
> > + return ret;
> > + }
> > +
> > + /* Set stream on register */
> > + return i2c_smbus_write_byte_data(client, REG_SC_CTRL_MODE,
> > + SC_CTRL_MODE_STREAMING);
> > +}
>
> ...
>
> > +/*
>
> Was your intention to declare it as a kernel doc?
>

Removed in next release.

> > + * ov02a10_set_exposure - Function called when setting exposure time
> > + * @priv: Pointer to device structure
> > + * @val: Variable for exposure time, in the unit of micro-second
> > + *
> > + * Set exposure time based on input value.
> > + *
> > + * Return: 0 on success
> > + */
> > +static int ov02a10_set_exposure(struct ov02a10 *ov02a10, int val)
>
> ...
>
> > +static int ov02a10_check_hwcfg(struct device *dev, struct ov02a10 *ov02a10)
> > +{
> > + struct fwnode_handle *ep;
> > + struct fwnode_handle *fwnode = dev_fwnode(dev);
> > + struct v4l2_fwnode_endpoint bus_cfg = {
> > + .bus_type = V4L2_MBUS_CSI2_DPHY,
> > + };
> > + unsigned int i, j;
> > + int ret;
>
> > + if (!fwnode)
> > + return -EINVAL;
>
> Basically you can avoid this check, but it's up to you.
>

I'd like to keep it. Thank you.

> > + ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
> > + if (!ep)
> > + return -ENXIO;
> > +
> > + ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
> > + fwnode_handle_put(ep);
> > + if (ret)
> > + return ret;
> > +
> > + for (i = 0; i < ARRAY_SIZE(link_freq_menu_items); i++) {
> > + for (j = 0; j < bus_cfg.nr_of_link_frequencies; j++) {
> > + if (link_freq_menu_items[i] ==
> > + bus_cfg.link_frequencies[j]) {
> > + ov02a10->freq_index = i;
> > + break;
> > + }
> > + }
> > +
> > + if (j == bus_cfg.nr_of_link_frequencies) {
> > + dev_err(dev, "no link frequency %lld supported\n",
> > + link_freq_menu_items[i]);
> > + ret = -EINVAL;
> > + break;
> > + }
> > + }
> > +
> > + v4l2_fwnode_endpoint_free(&bus_cfg);
> > +
> > + return ret;
> > +}
>
> ...
>
> > + fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
>
> Same Q as per previous reviews. Why device property API can't be used here?
>
> And everywhere else when you have
> fwnode_property_read_*(dev_fwnode(dev), ...)
> calls.
>

Thanks for the reminder.
'fwnode_property_read_u32' and 'fwnode_property_read_u32_array' would be
replaced in next release if local test passes.