Re: [PATCHv4 4/4] drm/tegra: add cec-notifier support

[Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

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On Thu, Oct 19, 2017 at 03:17:16PM +0200, Thierry Reding wrote:
> On Mon, Sep 11, 2017 at 02:29:52PM +0200, Hans Verkuil wrote:
> > From: Hans Verkuil <hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> > 
> > In order to support CEC the HDMI driver has to inform the CEC driver
> > whenever the physical address changes. So when the EDID is read the
> > CEC driver has to be informed and whenever the hotplug detect goes
> > away.
> > 
> > This is done through the cec-notifier framework.
> > 
> > The link between the HDMI driver and the CEC driver is done through
> > the hdmi_phandle in the tegra-cec node in the device tree.
> > 
> > Signed-off-by: Hans Verkuil <hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> > ---
> >  drivers/gpu/drm/tegra/Kconfig  | 1 +
> >  drivers/gpu/drm/tegra/drm.h    | 3 +++
> >  drivers/gpu/drm/tegra/hdmi.c   | 9 +++++++++
> >  drivers/gpu/drm/tegra/output.c | 6 ++++++
> >  4 files changed, 19 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/tegra/Kconfig b/drivers/gpu/drm/tegra/Kconfig
> > index 2db29d67193d..c882918c2024 100644
> > --- a/drivers/gpu/drm/tegra/Kconfig
> > +++ b/drivers/gpu/drm/tegra/Kconfig
> > @@ -8,6 +8,7 @@ config DRM_TEGRA
> >  	select DRM_PANEL
> >  	select TEGRA_HOST1X
> >  	select IOMMU_IOVA if IOMMU_SUPPORT
> > +	select CEC_CORE if CEC_NOTIFIER
> >  	help
> >  	  Choose this option if you have an NVIDIA Tegra SoC.
> >  
> > diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
> > index 6d6da01282f3..c0a18b60caf1 100644
> > --- a/drivers/gpu/drm/tegra/drm.h
> > +++ b/drivers/gpu/drm/tegra/drm.h
> > @@ -212,6 +212,8 @@ int tegra_dc_state_setup_clock(struct tegra_dc *dc,
> >  			       struct clk *clk, unsigned long pclk,
> >  			       unsigned int div);
> >  
> > +struct cec_notifier;
> > +
> >  struct tegra_output {
> >  	struct device_node *of_node;
> >  	struct device *dev;
> > @@ -219,6 +221,7 @@ struct tegra_output {
> >  	struct drm_panel *panel;
> >  	struct i2c_adapter *ddc;
> >  	const struct edid *edid;
> > +	struct cec_notifier *notifier;
> >  	unsigned int hpd_irq;
> >  	int hpd_gpio;
> >  	enum of_gpio_flags hpd_gpio_flags;
> > diff --git a/drivers/gpu/drm/tegra/hdmi.c b/drivers/gpu/drm/tegra/hdmi.c
> > index cda0491ed6bf..fbf14e1efd0e 100644
> > --- a/drivers/gpu/drm/tegra/hdmi.c
> > +++ b/drivers/gpu/drm/tegra/hdmi.c
> > @@ -21,6 +21,8 @@
> >  
> >  #include <sound/hda_verbs.h>
> >  
> > +#include <media/cec-notifier.h>
> > +
> >  #include "hdmi.h"
> >  #include "drm.h"
> >  #include "dc.h"
> > @@ -1720,6 +1722,10 @@ static int tegra_hdmi_probe(struct platform_device *pdev)
> >  		return PTR_ERR(hdmi->vdd);
> >  	}
> >  
> > +	hdmi->output.notifier = cec_notifier_get(&pdev->dev);
> > +	if (hdmi->output.notifier == NULL)
> > +		return -ENOMEM;
> > +
> >  	hdmi->output.dev = &pdev->dev;
> >  
> >  	err = tegra_output_probe(&hdmi->output);
> > @@ -1778,6 +1784,9 @@ static int tegra_hdmi_remove(struct platform_device *pdev)
> >  
> >  	tegra_output_remove(&hdmi->output);
> >  
> > +	if (hdmi->output.notifier)
> > +		cec_notifier_put(hdmi->output.notifier);
> > +
> >  	return 0;
> >  }
> >  
> > diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
> > index 595d1ec3e02e..57c052521a44 100644
> > --- a/drivers/gpu/drm/tegra/output.c
> > +++ b/drivers/gpu/drm/tegra/output.c
> > @@ -11,6 +11,8 @@
> >  #include <drm/drm_panel.h>
> >  #include "drm.h"
> >  
> > +#include <media/cec-notifier.h>
> > +
> >  int tegra_output_connector_get_modes(struct drm_connector *connector)
> >  {
> >  	struct tegra_output *output = connector_to_output(connector);
> > @@ -33,6 +35,7 @@ int tegra_output_connector_get_modes(struct drm_connector *connector)
> >  		edid = drm_get_edid(connector, output->ddc);
> >  
> >  	drm_mode_connector_update_edid_property(connector, edid);
> > +	cec_notifier_set_phys_addr_from_edid(output->notifier, edid);
> 
> I had to guard this with:
> 
> 	#if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
> 	...
> 	#endif
> 
> to enable this driver to be built without CEC_NOTIFIER enabled. I see
> that there are stubs defined if the above is false, but for some reason
> they don't seem to be there for me either.

Nevermind that. This was not actually failing. However, ...

> >  
> >  	if (edid) {
> >  		err = drm_add_edid_modes(connector, edid);
> > @@ -68,6 +71,9 @@ tegra_output_connector_detect(struct drm_connector *connector, bool force)
> >  			status = connector_status_connected;
> >  	}
> >  
> > +	if (status != connector_status_connected)
> > +		cec_notifier_phys_addr_invalidate(output->notifier);

This doesn't seem to exist in v4.14-rc1 which is the base for the
drm/tegra tree for v4.15. I see this function will be introduced in
v4.15 via the media tree.

How about if I replace this by:

	cec_notifier_set_phys(output->notifier, CEC_PHYS_ADDR_INVALID);

for now and switch it over to the new function after v4.15-rc1? That way
we can avoid the extra dependency between the media and drm trees.

Thierry

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