linux-kernel - [PATCH v3 2/5] drm/bridge: Add .get

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Message-Id: <20230218111712.2380225-3-treapking@chromium.org>
Date:   Sat, 18 Feb 2023 19:17:09 +0800
From:   Pin-yen Lin <treapking@...omium.org>
To:     Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Benson Leung <bleung@...omium.org>
Cc:     Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        devicetree@...r.kernel.org,
        Nicolas Boichat <drinkcat@...omium.org>,
        chrome-platform@...ts.linux.dev, linux-kernel@...r.kernel.org,
        Guenter Roeck <groeck@...omium.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org,
        Philipp Zabel <p.zabel@...gutronix.de>,
        linux-arm-kernel@...ts.infradead.org,
        Pin-yen Lin <treapking@...omium.org>
Subject: [PATCH v3 2/5] drm/bridge: Add .get_edid callback for anx7688 driver

Allow the driver to read EDID when ddc-i2c-bus phandle is present in
the device node.

Signed-off-by: Pin-yen Lin <treapking@...omium.org>
---

Changes in v3:
- New in v3

 drivers/gpu/drm/bridge/cros-ec-anx7688.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/bridge/cros-ec-anx7688.c b/drivers/gpu/drm/bridge/cros-ec-anx7688.c
index fa91bdeddef0..a16294c87940 100644
--- a/drivers/gpu/drm/bridge/cros-ec-anx7688.c
+++ b/drivers/gpu/drm/bridge/cros-ec-anx7688.c
@@ -6,6 +6,7 @@
  */
 
 #include <drm/drm_bridge.h>
+#include <drm/drm_edid.h>
 #include <drm/drm_print.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
@@ -91,14 +92,24 @@ static bool cros_ec_anx7688_bridge_mode_fixup(struct drm_bridge *bridge,
 	return totalbw >= requiredbw;
 }
 
+static struct edid *cros_ec_anx7688_get_edid(struct drm_bridge *bridge,
+					     struct drm_connector *connector)
+{
+	struct cros_ec_anx7688 *anx7688 = bridge_to_cros_ec_anx7688(bridge);
+
+	return drm_get_edid(connector, anx7688->bridge.ddc);
+}
+
 static const struct drm_bridge_funcs cros_ec_anx7688_bridge_funcs = {
 	.mode_fixup = cros_ec_anx7688_bridge_mode_fixup,
+	.get_edid = cros_ec_anx7688_get_edid,
 };
 
 static int cros_ec_anx7688_bridge_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct cros_ec_anx7688 *anx7688;
+	struct device_node *phandle;
 	u16 vendor, device, fw_version;
 	u8 buffer[4];
 	int ret;
@@ -153,6 +164,19 @@ static int cros_ec_anx7688_bridge_probe(struct i2c_client *client)
 		DRM_WARN("Old ANX7688 FW version (0x%04x), not filtering\n",
 			 fw_version);
 
+
+	phandle = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
+	if (phandle) {
+		anx7688->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
+		of_node_put(phandle);
+		if (!anx7688->bridge.ddc)
+			return -EPROBE_DEFER;
+	} else {
+		dev_dbg(dev, "No I2C bus specified, disabling EDID readout\n");
+	}
+	if (anx7688->bridge.ddc)
+		anx7688->bridge.ops |= DRM_BRIDGE_OP_EDID;
+
 	anx7688->bridge.funcs = &cros_ec_anx7688_bridge_funcs;
 	drm_bridge_add(&anx7688->bridge);
 
-- 
2.39.2.637.g21b0678d19-goog