[PATCH 2/4] drm/bridge: dw-hdmi: add cec notifier support

On 09/06/17 15:38, Russell King - ARM Linux wrote:

On Fri, Jun 09, 2017 at 02:59:20PM +0200, Neil Armstrong wrote:

quoted

On 05/30/2017 04:23 PM, Russell King wrote:

quoted

Add CEC notifier support to the HDMI bridge driver, so that the CEC
part of the IP can receive its physical address.

Signed-off-by: Russell King <redacted>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 4e1f54a675d8..966422576c44 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

@@ -36,7 +36,10 @@
 #include "dw-hdmi.h"
 #include "dw-hdmi-audio.h"
 
+#include <media/cec-notifier.h>
+
 #define DDC_SEGMENT_ADDR	0x30
+
 #define HDMI_EDID_LEN		512
 
 enum hdmi_datamap {

@@ -173,6 +176,8 @@ struct dw_hdmi {
 
 	unsigned int reg_shift;
 	struct regmap *regm;
+
+	struct cec_notifier *cec_notifier;
 };
 
 #define HDMI_IH_PHY_STAT0_RX_SENSE \

@@ -1870,6 +1875,7 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
 		hdmi->sink_is_hdmi = drm_detect_hdmi_monitor(edid);
 		hdmi->sink_has_audio = drm_detect_monitor_audio(edid);
 		drm_mode_connector_update_edid_property(connector, edid);
+		cec_notifier_set_phys_addr_from_edid(hdmi->cec_notifier, edid);
 		ret = drm_add_edid_modes(connector, edid);
 		/* Store the ELD */
 		drm_edid_to_eld(connector, edid);

@@ -2108,11 +2114,16 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
 	 * ask the source to re-read the EDID.
 	 */
 	if (intr_stat &
-	    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD))
+	    (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) {
 		__dw_hdmi_setup_rx_sense(hdmi,
 					 phy_stat & HDMI_PHY_HPD,
 					 phy_stat & HDMI_PHY_RX_SENSE);
 
+		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
+			cec_notifier_set_phys_addr(hdmi->cec_notifier,
+						   CEC_PHYS_ADDR_INVALID);
+	}
+
 	if (intr_stat & HDMI_IH_PHY_STAT0_HPD) {
 		dev_dbg(hdmi->dev, "EVENT=%s\n",
 			phy_int_pol & HDMI_PHY_HPD ? "plugin" : "plugout");

@@ -2365,6 +2376,12 @@ __dw_hdmi_probe(struct platform_device *pdev,
 	if (ret)
 		goto err_iahb;
 
+	hdmi->cec_notifier = cec_notifier_get(dev);
+	if (!hdmi->cec_notifier) {
+		ret = -ENOMEM;
+		goto err_iahb;
+	}
+
 	/*
 	 * To prevent overflows in HDMI_IH_FC_STAT2, set the clk regenerator
 	 * N and cts values before enabling phy

@@ -2437,6 +2454,9 @@ __dw_hdmi_probe(struct platform_device *pdev,
 		hdmi->ddc = NULL;
 	}
 
+	if (hdmi->cec_notifier)
+		cec_notifier_put(hdmi->cec_notifier);
+
 	clk_disable_unprepare(hdmi->iahb_clk);
 err_isfr:
 	clk_disable_unprepare(hdmi->isfr_clk);

Hi Archit,

I think this one could go through drm-next since it's quite
standalone and will reduce the DW-HDMI CEC patchset and dependencies.

Not a good idea.  If you read all the comments, Hans is suggesting that
CEC should be part of dw-hdmi itself, not stand-alone.  That would mean
this patch probably changes - basically, with CEC support built-in to
dw-hdmi, we don't need the notifier stuff.

So, I'd suggest _not_ merging it at the moment, because the patch could
well become obsolete.

Wait until the CEC changes that Hans has talked about have hit mainline
and I've had a chance to rework this for those.  We're waiting on Mauro
for that at the moment.

The patches are in mainline now. Note: you may get the occasional kbuild
robot emails since there are a few more CEC patches pending for 4.12 but
that's just slight CEC header changes to fix obscure .config combinations.
It should not affect your patches. I expect those pending fixes to hit
mainline some time next week.

(I do find it rather frustrating that CEC seems to evolve very rapidly,
it makes it quite difficult to publish a patch set, and get it merged.)

It's a pretty new framework and yours and my own work on drm drivers showed
a few shortcomings, primarily in the way the kernel config options were set
up for CEC.

I believe this is now sorted with 4.12.

What makes CEC a bit tricky is that it straddles two subsystems: drm and media.
Always harder to synchronize things.

Regards,

	Hans