Re: [PATCH v7 10/24] drm/rockchip: dw_hdmi: Add support for hclk

[Dmitry Osipenko <digetx@gmail.com>]

25.02.2022 13:49, Sascha Hauer пишет:
> On Fri, Feb 25, 2022 at 01:26:14PM +0300, Dmitry Osipenko wrote:
>> 25.02.2022 10:51, Sascha Hauer пишет:
>>> The rk3568 HDMI has an additional clock that needs to be enabled for the
>>> HDMI controller to work. The purpose of that clock is not clear. It is
>>> named "hclk" in the downstream driver, so use the same name.
>>>
>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>> ---
>>>
>>> Notes:
>>>     Changes since v5:
>>>     - Use devm_clk_get_optional rather than devm_clk_get
>>>
>>>  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 16 ++++++++++++++++
>>>  1 file changed, 16 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
>>> index fe4f9556239ac..c6c00e8779ab5 100644
>>> --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
>>> +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
>>> @@ -76,6 +76,7 @@ struct rockchip_hdmi {
>>>  	const struct rockchip_hdmi_chip_data *chip_data;
>>>  	struct clk *ref_clk;
>>>  	struct clk *grf_clk;
>>> +	struct clk *hclk_clk;
>>>  	struct dw_hdmi *hdmi;
>>>  	struct regulator *avdd_0v9;
>>>  	struct regulator *avdd_1v8;
>>> @@ -229,6 +230,14 @@ static int rockchip_hdmi_parse_dt(struct rockchip_hdmi *hdmi)
>>>  		return PTR_ERR(hdmi->grf_clk);
>>>  	}
>>>  
>>> +	hdmi->hclk_clk = devm_clk_get_optional(hdmi->dev, "hclk");
>>> +	if (PTR_ERR(hdmi->hclk_clk) == -EPROBE_DEFER) {
>>
>> Have you tried to investigate the hclk? I'm still thinking that's not
>> only HDMI that needs this clock and then the hardware description
>> doesn't look correct.
> 
> I am still not sure what you mean. Yes, it's not only the HDMI that
> needs this clock. The VOP2 needs it as well and the driver handles that.

I'm curious whether DSI/DP also need that clock to be enabled. If they
do, then you aren't modeling h/w properly AFAICS.

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