Hello Frank, On 19.12.24 18:34, Frank Li wrote: > On Thu, Dec 19, 2024 at 08:25:27AM +0100, Ahmad Fatoum wrote: >> The HDMI DDC pads can be muxed either to an i.MX I2C controller or >> to a limited I2C controller within the Designware HDMI bridge. >> >> So far we muxed the pads to the HDMI bridge, but the i.MX I2C controller >> is the better choice: > > Switch to the i.MX I2C controller because > >> >> - We use DDC/CI commands for display brightness configuration, but the >> Linux driver refuses[1] transfers to/from address 0x37, because the >> controller doesn't support multi-byte requests. > > Designware HDMI Limited I2C controller doesn't support multi-byte > requests and display brightness configuration by DDC/CI command need it. > >> >> - The driver doesn't support I2C bus recovery, but we need that, >> because some HDMI panels used with the board can be flaky. > > Designware HDMI Limited I2C controller doesn't support I2C bus > recovery. > >> >> As the i.MX I2C controller doesn't have either of these limitations, >> let's make use of it instead. > > Reduntant. can be removed. Sorry, I am very much open to review feedback, but I fail to see how your subjective take improves things. Thanks, Ahmad > > Frank >> >> [1]: https://lore.kernel.org/all/20190722181945.244395-1-mka@xxxxxxxxxxxx/ >> >> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> >> --- >> .../boot/dts/freescale/imx8mp-skov-revb-hdmi.dts | 26 ++++++++++++++++++++-- >> 1 file changed, 24 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-hdmi.dts b/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-hdmi.dts >> index c1ca69da3cb8..206116be8166 100644 >> --- a/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-hdmi.dts >> +++ b/arch/arm64/boot/dts/freescale/imx8mp-skov-revb-hdmi.dts >> @@ -9,12 +9,34 @@ / { >> compatible = "skov,imx8mp-skov-revb-hdmi", "fsl,imx8mp"; >> }; >> >> +&i2c5 { >> + pinctrl-names = "default", "gpio"; >> + pinctrl-0 = <&pinctrl_i2c5>; >> + pinctrl-1 = <&pinctrl_i2c5_gpio>; >> + scl-gpios = <&gpio3 26 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; >> + sda-gpios = <&gpio3 27 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; >> + clock-frequency = <100000>; >> + status = "okay"; >> +}; >> + >> &iomuxc { >> pinctrl_hdmi: hdmigrp { >> fsl,pins = < >> - MX8MP_IOMUXC_HDMI_DDC_SCL__HDMIMIX_HDMI_SCL 0x1c3 >> - MX8MP_IOMUXC_HDMI_DDC_SDA__HDMIMIX_HDMI_SDA 0x1c3 >> MX8MP_IOMUXC_HDMI_HPD__HDMIMIX_HDMI_HPD 0x19 >> >; >> }; >> + >> + pinctrl_i2c5: i2c5grp { >> + fsl,pins = < >> + MX8MP_IOMUXC_HDMI_DDC_SCL__I2C5_SCL 0x400001c2 >> + MX8MP_IOMUXC_HDMI_DDC_SDA__I2C5_SDA 0x400001c2 >> + >; >> + }; >> + >> + pinctrl_i2c5_gpio: i2c5gpiogrp { >> + fsl,pins = < >> + MX8MP_IOMUXC_HDMI_DDC_SCL__GPIO3_IO26 0x400001c2 >> + MX8MP_IOMUXC_HDMI_DDC_SDA__GPIO3_IO27 0x400001c2 >> + >; >> + }; >> }; >> >> -- >> 2.39.5 >> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
