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Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0613-dt-Drop-I2C-for-Pi4-HDMI-interfaces-to-97.5kHz.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0613-dt-Drop-I2C-for-Pi4-HDMI-interfaces-to-97.5kHz.patch35
1 files changed, 35 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0613-dt-Drop-I2C-for-Pi4-HDMI-interfaces-to-97.5kHz.patch b/target/linux/bcm27xx/patches-5.4/950-0613-dt-Drop-I2C-for-Pi4-HDMI-interfaces-to-97.5kHz.patch
new file mode 100644
index 0000000000..cd18cd1309
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0613-dt-Drop-I2C-for-Pi4-HDMI-interfaces-to-97.5kHz.patch
@@ -0,0 +1,35 @@
+From 460ddd2729f0dbb2723e48f3a22ffccbb78b42c7 Mon Sep 17 00:00:00 2001
+From: Dave Stevenson <dave.stevenson@raspberrypi.com>
+Date: Tue, 31 Mar 2020 17:54:08 +0100
+Subject: [PATCH] dt: Drop I2C for Pi4 HDMI interfaces to 97.5kHz.
+
+It was set to 390kHz, which is outside of the required spec for
+reading HDMI (max 100kHz). The i2c-brcmstb driver only supports
+a number of fixed bus speeds, of which 97.5kHz is the closest to
+100kHz without exceeding it.
+
+Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
+---
+ arch/arm/boot/dts/bcm2711.dtsi | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/arm/boot/dts/bcm2711.dtsi
++++ b/arch/arm/boot/dts/bcm2711.dtsi
+@@ -358,7 +358,7 @@
+ compatible = "brcm,bcm2711-hdmi-i2c";
+ reg = <0x7ef04500 0x100>, <0x7ef00b00 0x300>;
+ reg-names = "bsc", "auto-i2c";
+- clock-frequency = <390000>;
++ clock-frequency = <97500>;
+ status = "disabled";
+ };
+
+@@ -395,7 +395,7 @@
+ compatible = "brcm,bcm2711-hdmi-i2c";
+ reg = <0x7ef09500 0x100>, <0x7ef05b00 0x300>;
+ reg-names = "bsc", "auto-i2c";
+- clock-frequency = <390000>;
++ clock-frequency = <97500>;
+ status = "disabled";
+ };
+ };