From mboxrd@z Thu Jan 1 00:00:00 1970 From: dinguyen@kernel.org (Dinh Nguyen) Date: Wed, 4 Jan 2017 18:21:24 -0600 Subject: [PATCH 02/12] ARM: dts: socfpga: set desired i2c clock on Cyclone5 and Arria5 devkits In-Reply-To: <1483575694-29599-1-git-send-email-dinguyen@kernel.org> References: <1483575694-29599-1-git-send-email-dinguyen@kernel.org> Message-ID: <1483575694-29599-3-git-send-email-dinguyen@kernel.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The I2C LCD display on the Cyclone5 and Arria5 devkits is only capable of the standard 100 kHz clock. Set the "clock-frequency" of the I2C node to be 100000. Signed-off-by: Dinh Nguyen --- arch/arm/boot/dts/socfpga_arria5_socdk.dts | 8 ++++++++ arch/arm/boot/dts/socfpga_cyclone5_socdk.dts | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/arch/arm/boot/dts/socfpga_arria5_socdk.dts b/arch/arm/boot/dts/socfpga_arria5_socdk.dts index fa70c39..8672edf 100644 --- a/arch/arm/boot/dts/socfpga_arria5_socdk.dts +++ b/arch/arm/boot/dts/socfpga_arria5_socdk.dts @@ -98,6 +98,14 @@ &i2c0 { status = "okay"; + clock-frequency = <100000>; + + /* + * adjust the falling times to decrease the i2c frequency to 50Khz + * because the LCD module does not work at the standard 100Khz + */ + i2c-sda-falling-time-ns = <5000>; + i2c-scl-falling-time-ns = <5000>; eeprom at 51 { compatible = "atmel,24c32"; diff --git a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts index 6d3188b..24650ba 100644 --- a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts +++ b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts @@ -98,6 +98,14 @@ &i2c0 { status = "okay"; + clock-frequency = <100000>; + + /* + * adjust the falling times to decrease the i2c frequency to 50Khz + * because the LCD module does not work at the standard 100Khz + */ + i2c-sda-falling-time-ns = <5000>; + i2c-scl-falling-time-ns = <5000>; eeprom at 51 { compatible = "atmel,24c32"; -- 2.7.4