Re: [PATCH v4 02/10] media: platform: Add c3 mipi csi2 driver

[Keke Li <keke.li@amlogic.com>]

On 2024/12/12 17:41, Jacopo Mondi wrote:
> [ EXTERNAL EMAIL ]
>
> Hi Keke
>
> On Thu, Dec 12, 2024 at 05:08:27PM +0800, Keke Li wrote:
>> On 2024/12/12 16:41, Jacopo Mondi wrote:
>>> [ EXTERNAL EMAIL ]
>>>
>>> Hi Keke,
>>>     a question for Laurent and Sakari
>>>
>>> On Thu, Dec 05, 2024 at 05:04:28PM +0800, Keke Li via B4 Relay wrote:
>>>> From: Keke Li <keke.li@amlogic.com>
>>>>
>>>> This driver is used to receive mipi data from image sensor.
>>>>
>>>> Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
>>>> Signed-off-by: Keke Li <keke.li@amlogic.com>
>>> [snip]
>>>
>>>> +
>>>> +static int c3_mipi_csi_configure_clocks(struct csi_device *csi)
>>>> +{
>>>> +     const struct csi_info *info = csi->info;
>>>> +     int ret;
>>>> +     u32 i;
>>>> +
>>>> +     for (i = 0; i < info->clock_num; i++)
>>>> +             csi->clks[i].id = info->clocks[i];
>>>> +
>>>> +     ret = devm_clk_bulk_get(csi->dev, info->clock_num, csi->clks);
>>>> +     if (ret)
>>>> +             return ret;
>>>> +
>>>> +     for (i = 0; i < info->clock_num; i++) {
>>>> +             if (!info->clock_rates[i])
>>>> +                     continue;
>>>> +             ret = clk_set_rate(csi->clks[i].clk, info->clock_rates[i]);
>>>> +             if (ret) {
>>>> +                     dev_err(csi->dev, "Failed to set %s rate %u\n", info->clocks[i],
>>>> +                             info->clock_rates[i]);
>>>> +                     return ret;
>>>> +             }
>>>> +     }
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>> [snip]
>>>
>>>> +
>>>> +static const struct csi_info c3_mipi_csi_info = {
>>>> +     .clocks = {"vapb", "phy0"},
>>>> +     .clock_rates = {0, 200000000},
>>>> +     .clock_num = 2
>>>> +};
>>>> +
>>>> +static const struct of_device_id c3_mipi_csi_of_match[] = {
>>>> +     { .compatible = "amlogic,c3-mipi-csi2",
>>>> +       .data = &c3_mipi_csi_info,
>>>> +     },
>>>> +     { },
>>>> +};
>>> All the drivers in this patch series implement the same pattern when
>>> it comes to handling clock. There's a list of clock providers in the
>>> driver associated with a clock frequency. The driver bulk_get the
>>> clocks and set_rate() using the per-compatible info table.
>>>
>>> Do you think this should rather come from dts using the
>>> assigned-clocks and assigned-clock-rates properties ?
>> Yes,  I think your suggestion is OK.
>>
>> Will test it.
>>
>> If apply your suggestion, do I need to modify the relevant yaml file?
>>
> Do you mean the binding files ?
>
> You could add to the example
>
> --- a/Documentation/devicetree/bindings/media/amlogic,c3-isp.yaml
> +++ b/Documentation/devicetree/bindings/media/amlogic,c3-isp.yaml
> @@ -73,6 +73,8 @@ examples:
>               clocks = <&clkc_periphs CLKID_VAPB>,
>                        <&clkc_periphs CLKID_ISP0>;
>               clock-names = "vapb", "isp0";
> +            assigned-clocks = <&clkc_periphs CLKID_ISP0>;
> +            assigned-clock-rates = <400000000>;
>               interrupts = <GIC_SPI 145 IRQ_TYPE_EDGE_RISING>;
>
>               port {
>
>
> As your binding document has "additionalProperties: false" I thought
> you had to add:
>
>    assigned-clocks: true
>    assigned-clock-rates: true
>
> As in my understanding "additionalProperties: false" means "whatever
> is not explicitly allowed is forbidden". However I might be wrong as
> validating the binding even without the two above entries work well
> (and I see other bindings doing the same)
>
> DT maintainers are in cc


OK, will add 'assigned-clocks' and 'assigned-clock-rates' in dt-binding. 
Thanks very much.