[PATCH] drm/sun4i: dw-hdmi: Fix HDMI PHY clock setup

[Jernej Škrabec]

Hi!

Dne torek, 14. september 2021 ob 10:59:22 CEST je Ondřej Jirman napisal(a):
> Hello Jernej,
> 
> On Mon, Sep 13, 2021 at 07:21:54PM +0200, Jernej Skrabec wrote:
> > Recent rework, which made HDMI PHY driver a platform device, inadvertely
> > reversed clock setup order. HW is very touchy about it. Proper way is to
> > handle controllers resets and clocks first and HDMI PHYs second.
> > 
> > Currently, without this fix, first mode set completely fails (nothing on
> > HDMI monitor) on H3 era PHYs. On H6, it still somehow work.
> > 
> > Move HDMI PHY reset & clocks handling to sun8i_hdmi_phy_init() which
> > will assure that code is executed after controllers reset & clocks are
> > handled. Additionally, add sun8i_hdmi_phy_deinit() which will deinit
> > them at controllers driver unload.
> > 
> > Tested on A64, H3, H6 and R40.
> > 
> > Fixes: 9bf3797796f5 ("drm/sun4i: dw-hdmi: Make HDMI PHY into a platform 
device")
> > Signed-off-by: Jernej Skrabec <jernej.skrabec at gmail.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c  |  7 +-
> >  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h  |  4 +-
> >  drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 97 ++++++++++++++------------
> >  3 files changed, 61 insertions(+), 47 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/
sun8i_dw_hdmi.c
> > index f75fb157f2ff..5fa5407ac583 100644
> > --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> > +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
> > @@ -216,11 +216,13 @@ static int sun8i_dw_hdmi_bind(struct device *dev, 
struct device *master,
> >  		goto err_disable_clk_tmds;
> >  	}
> 
> ^^^ This looks like...
> 
> > +	ret = sun8i_hdmi_phy_init(hdmi->phy);
> > +	if (ret)
> > +		return ret;
> 
> ... you need 'goto err_disable_clk_tmds;' here, instead.

Ah, right. Will fix in v2.

> 
> > +
> >  	drm_encoder_helper_add(encoder, 
&sun8i_dw_hdmi_encoder_helper_funcs);
> >  	drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS);
> >  
> > -	sun8i_hdmi_phy_init(hdmi->phy);
> > -
> >  	plat_data->mode_valid = hdmi->quirks->mode_valid;
> >  	plat_data->use_drm_infoframe = hdmi->quirks->use_drm_infoframe;
> >  	sun8i_hdmi_phy_set_ops(hdmi->phy, plat_data);
> > @@ -262,6 +264,7 @@ static void sun8i_dw_hdmi_unbind(struct device *dev, 
struct device *master,
> >  	struct sun8i_dw_hdmi *hdmi = dev_get_drvdata(dev);
> >  
> >  	dw_hdmi_unbind(hdmi->hdmi);
> > +	sun8i_hdmi_phy_deinit(hdmi->phy);
> >  	clk_disable_unprepare(hdmi->clk_tmds);
> >  	reset_control_assert(hdmi->rst_ctrl);
> >  	gpiod_set_value(hdmi->ddc_en, 0);
> > diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/
sun8i_dw_hdmi.h
> > index 74f6ed0e2570..bffe1b9cd3dc 100644
> > --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
> > +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
> > @@ -169,6 +169,7 @@ struct sun8i_hdmi_phy {
> >  	struct clk			*clk_phy;
> >  	struct clk			*clk_pll0;
> >  	struct clk			*clk_pll1;
> > +	struct device			*dev;
> >  	unsigned int			rcal;
> >  	struct regmap			*regs;
> >  	struct reset_control		*rst_phy;
> > @@ -205,7 +206,8 @@ encoder_to_sun8i_dw_hdmi(struct drm_encoder *encoder)
> >  
> >  int sun8i_hdmi_phy_get(struct sun8i_dw_hdmi *hdmi, struct device_node 
*node);
> >  
> > -void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy);
> > +int sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy);
> > +void sun8i_hdmi_phy_deinit(struct sun8i_hdmi_phy *phy);
> >  void sun8i_hdmi_phy_set_ops(struct sun8i_hdmi_phy *phy,
> >  			    struct dw_hdmi_plat_data *plat_data);
> >  
> > diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c b/drivers/gpu/drm/
sun4i/sun8i_hdmi_phy.c
> > index c9239708d398..78b152973957 100644
> > --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> > +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> > @@ -506,9 +506,60 @@ static void sun8i_hdmi_phy_init_h3(struct 
sun8i_hdmi_phy *phy)
> >  	phy->rcal = (val & SUN8I_HDMI_PHY_ANA_STS_RCAL_MASK) >> 2;
> >  }
> >  
> > -void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy)
> > +int sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy)
> >  {
> > +	int ret;
> > +
> > +	ret = reset_control_deassert(phy->rst_phy);
> > +	if (ret) {
> > +		dev_err(phy->dev, "Cannot deassert phy reset control: 
%d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = clk_prepare_enable(phy->clk_bus);
> > +	if (ret) {
> > +		dev_err(phy->dev, "Cannot enable bus clock: %d\n", 
ret);
> > +		goto err_deassert_rst_phy;
> 
> I know it was there before, but please:
> 
> s/deassert/assert/

Ok.

Best regards,
Jernej

> 
> kind regards,
> 	o.
> 
> > +	}
> > +
> > +	ret = clk_prepare_enable(phy->clk_mod);
> > +	if (ret) {
> > +		dev_err(phy->dev, "Cannot enable mod clock: %d\n", 
ret);
> > +		goto err_disable_clk_bus;
> > +	}
> > +
> > +	if (phy->variant->has_phy_clk) {
> > +		ret = sun8i_phy_clk_create(phy, phy->dev,
> > +					   phy->variant-
>has_second_pll);
> > +		if (ret) {
> > +			dev_err(phy->dev, "Couldn't create the PHY 
clock\n");
> > +			goto err_disable_clk_mod;
> > +		}
> > +
> > +		clk_prepare_enable(phy->clk_phy);
> > +	}
> > +
> >  	phy->variant->phy_init(phy);
> > +
> > +	return 0;
> > +
> > +err_disable_clk_mod:
> > +	clk_disable_unprepare(phy->clk_mod);
> > +err_disable_clk_bus:
> > +	clk_disable_unprepare(phy->clk_bus);
> > +err_deassert_rst_phy:
> > +	reset_control_assert(phy->rst_phy);
> > +
> > +	return ret;
> > +}
> > +
> >
> > [......]
>