target/linux/bcm27xx/patches-6.1/950-1264-ARM-dts-rp1-Add-a-safe-I2C-SDA-hold-time.patch

   1 From 15dedc2ad5a9073b8639881680672214f605a5c6 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Wed, 31 Jan 2024 17:44:02 +0000
   4 Subject: [PATCH 1264/1295] ARM: dts: rp1: Add a safe I2C SDA hold time
   5
   6 Failing to set a reasonable SDA hold time can cause SDA to change too
   7 close to the falling edge of SCL. 300ns is the recommended minimum
   8 interval between the two at 100kHz and 400kHz, and also seems to
   9 work at 1MHz, so use that.
  10
  11 See: https://github.com/raspberrypi/linux/issues/5914
  12
  13 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  14 ---
  15  arch/arm/boot/dts/rp1.dtsi | 7 +++++++
  16  1 file changed, 7 insertions(+)
  17
  18 --- a/arch/arm/boot/dts/rp1.dtsi
  19 +++ b/arch/arm/boot/dts/rp1.dtsi
  20 @@ -307,6 +307,7 @@
  21                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  22                         i2c-scl-rising-time-ns = <65>;
  23                         i2c-scl-falling-time-ns = <100>;
  24 +                       i2c-sda-hold-time-ns = <300>;
  25                         status = "disabled";
  26                 };
  27
  28 @@ -317,6 +318,7 @@
  29                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  30                         i2c-scl-rising-time-ns = <65>;
  31                         i2c-scl-falling-time-ns = <100>;
  32 +                       i2c-sda-hold-time-ns = <300>;
  33                         status = "disabled";
  34                 };
  35
  36 @@ -327,6 +329,7 @@
  37                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  38                         i2c-scl-rising-time-ns = <65>;
  39                         i2c-scl-falling-time-ns = <100>;
  40 +                       i2c-sda-hold-time-ns = <300>;
  41                         status = "disabled";
  42                 };
  43
  44 @@ -337,6 +340,7 @@
  45                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  46                         i2c-scl-rising-time-ns = <65>;
  47                         i2c-scl-falling-time-ns = <100>;
  48 +                       i2c-sda-hold-time-ns = <300>;
  49                         status = "disabled";
  50                 };
  51
  52 @@ -347,6 +351,7 @@
  53                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  54                         i2c-scl-rising-time-ns = <65>;
  55                         i2c-scl-falling-time-ns = <100>;
  56 +                       i2c-sda-hold-time-ns = <300>;
  57                         status = "disabled";
  58                 };
  59
  60 @@ -357,6 +362,7 @@
  61                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  62                         i2c-scl-rising-time-ns = <65>;
  63                         i2c-scl-falling-time-ns = <100>;
  64 +                       i2c-sda-hold-time-ns = <300>;
  65                         status = "disabled";
  66                 };
  67
  68 @@ -367,6 +373,7 @@
  69                         clocks = <&rp1_clocks RP1_CLK_SYS>;
  70                         i2c-scl-rising-time-ns = <65>;
  71                         i2c-scl-falling-time-ns = <100>;
  72 +                       i2c-sda-hold-time-ns = <300>;
  73                         status = "disabled";
  74                 };
  75