On 26.07.2018 12:44, Krzysztof Kozlowski wrote:

On 26 July 2018 at 12:12, Andrzej Hajda a.hajda@samsung.com wrote:

...

HDMI-HPD was set active low, moreover by default pincontrol chip sets pull-down on the pin. As a result HDMI driver assumes TV is always connected regardless of actual state. The patch fixes it.

Signed-off-by: Andrzej Hajda a.hajda@samsung.com

arch/arm/boot/dts/exynos5250-arndale.dts | 4 +++- arch/arm/boot/dts/exynos5250-pinctrl.dtsi | 5 +++++ 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts b/arch/arm/boot/dts/exynos5250-arndale.dts index 591023391f7d..26bae5157177 100644 --- a/arch/arm/boot/dts/exynos5250-arndale.dts +++ b/arch/arm/boot/dts/exynos5250-arndale.dts @@ -210,9 +210,11 @@ };

&hdmi {

•   pinctrl-names = "default";
  

•   pinctrl-0 = <&hdmi_hpd>;
    status = "okay";
    ddc = <&i2c_ddc>;
  

•   hpd-gpios = <&gpx3 7 GPIO_ACTIVE_LOW>;
  

•   hpd-gpios = <&gpx3 7 GPIO_ACTIVE_HIGH>;
  

The gpx3-7 (HDMI-HPD) has external pull up to... so maybe it should be active low? How can it go high if it is already high? I am not sure if this matters because the driver ignores the flags and responds on both falling and rising edge.

HDMI specification says HPD is active high! Arndale schematics are quite misleading - pull-up resistors near level shifter are marked as not-connected :) so there are no pull-ups. And there is pull-down resistor on right side of the level shifter. And finally with this patch it works as expected, without it it works sometimes.

Regards Andrzej

Best regards, Krzysztof

...

    vdd_osc-supply = <&ldo10_reg>;
    vdd_pll-supply = <&ldo8_reg>;
    vdd-supply = <&ldo8_reg>;

diff --git a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi index b25d520393b8..d31a68672bfa 100644 --- a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi +++ b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi @@ -599,6 +599,11 @@ samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>; samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>; };

•   hdmi_hpd: hdmi-hpd {
  

•           samsung,pins = "gpx3-7";
  

•           samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
  

•   };
  

};

&pinctrl_1 {

2.18.0

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On 26.07.2018 12:23, Krzysztof Kozlowski wrote:

On 26 July 2018 at 12:12, Andrzej Hajda a.hajda@samsung.com wrote:

...

HDMI-DDC for unknown reasons doesn't work with Exynos I2C controllers. Fortunately i2c-gpio comes to the rescue.

Wait... what? The I2C controller on SoC (or its driver) is buggy in some way and we need to use these pins as GPIO to run i2c-gpio driver there? It looks like workaround not a proper solution...

But at least working one :) Better solutions are welcome. This seems to be not uncommon issue, if you for example look into odroid vendor kernel you can even find hardcoded EDIDs :)

Regards Andrzej

Best regards, Krzysztof

...

Signed-off-by: Andrzej Hajda a.hajda@samsung.com

arch/arm/boot/dts/exynos5250-arndale.dts | 24 +++++++++++++++-------- arch/arm/boot/dts/exynos5250-pinctrl.dtsi | 6 ++++++ 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts b/arch/arm/boot/dts/exynos5250-arndale.dts index 816d89d4cefd..591023391f7d 100644 --- a/arch/arm/boot/dts/exynos5250-arndale.dts +++ b/arch/arm/boot/dts/exynos5250-arndale.dts @@ -211,7 +211,7 @@

&hdmi { status = "okay";

•   ddc = <&i2c_2>;
  

•   ddc = <&i2c_ddc>;
    hpd-gpios = <&gpx3 7 GPIO_ACTIVE_LOW>;
    vdd_osc-supply = <&ldo10_reg>;
    vdd_pll-supply = <&ldo8_reg>;
  

@@ -513,13 +513,6 @@ }; };

-&i2c_2 {

•   status = "okay";
  

•   /* used by HDMI DDC */
  

•   samsung,i2c-sda-delay = <100>;
  

•   samsung,i2c-max-bus-freq = <66000>;
  

-};

&i2c_3 { status = "okay";

@@ -608,3 +601,18 @@ status = "okay"; samsung,exynos-sataphy-i2c-phandle = <&sata_phy_i2c>; };

+&soc {

•   i2c_ddc: i2c-gpio {
  

•           pinctrl-names = "default";
  

•           pinctrl-0 = <&i2c2_gpio_bus>;
  

•           status = "okay";
  

•           compatible = "i2c-gpio";
  

•           gpios = <&gpa0 6 0 /* sda */
  

•                    &gpa0 7 0 /* scl */
  

•                   >;
  

•           i2c-gpio,delay-us = <2>;
  

•           #address-cells = <1>;
  

•           #size-cells = <0>;
  

•   };
  

+}; diff --git a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi index 6ff6dea29d44..b25d520393b8 100644 --- a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi +++ b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi @@ -225,6 +225,12 @@ samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>; };

•   i2c2_gpio_bus: i2c2-gpio-bus {
  

•           samsung,pins = "gpa0-6", "gpa0-7";
  

•           samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
  

•           samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
  

•   };
  

•   uart2_data: uart2-data {
            samsung,pins = "gpa1-0", "gpa1-1";
            samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
  

-- 2.18.0

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HDMI-DDC for unknown reasons doesn't work with Exynos I2C controllers. Fortunately i2c-gpio comes to the rescue.

Signed-off-by: Andrzej Hajda a.hajda@samsung.com --- arch/arm/boot/dts/exynos5250-arndale.dts | 28 ++++++++++++++++------- arch/arm/boot/dts/exynos5250-pinctrl.dtsi | 6 +++++ 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts b/arch/arm/boot/dts/exynos5250-arndale.dts index 816d89d4cefd..e7a9b9aa85f1 100644 --- a/arch/arm/boot/dts/exynos5250-arndale.dts +++ b/arch/arm/boot/dts/exynos5250-arndale.dts @@ -211,7 +211,7 @@

&hdmi { status = "okay"; - ddc = <&i2c_2>; + ddc = <&i2c_ddc>; hpd-gpios = <&gpx3 7 GPIO_ACTIVE_LOW>; vdd_osc-supply = <&ldo10_reg>; vdd_pll-supply = <&ldo8_reg>; @@ -513,13 +513,6 @@ }; };

-&i2c_2 { - status = "okay"; - /* used by HDMI DDC */ - samsung,i2c-sda-delay = <100>; - samsung,i2c-max-bus-freq = <66000>; -}; - &i2c_3 { status = "okay";

@@ -608,3 +601,22 @@ status = "okay"; samsung,exynos-sataphy-i2c-phandle = <&sata_phy_i2c>; }; + +&soc { + /* + * For unknown reasons HDMI-DDC does not work with Exynos I2C + * controllers. Lets use software I2C over GPIO pins as a workaround. + */ + i2c_ddc: i2c-gpio { + pinctrl-names = "default"; + pinctrl-0 = <&i2c2_gpio_bus>; + status = "okay"; + compatible = "i2c-gpio"; + gpios = <&gpa0 6 0 /* sda */ + &gpa0 7 0 /* scl */ + >; + i2c-gpio,delay-us = <2>; + #address-cells = <1>; + #size-cells = <0>; + }; +}; diff --git a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi index 6ff6dea29d44..b25d520393b8 100644 --- a/arch/arm/boot/dts/exynos5250-pinctrl.dtsi +++ b/arch/arm/boot/dts/exynos5250-pinctrl.dtsi @@ -225,6 +225,12 @@ samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>; };

+ i2c2_gpio_bus: i2c2-gpio-bus { + samsung,pins = "gpa0-6", "gpa0-7"; + samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>; + samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>; + }; + uart2_data: uart2-data { samsung,pins = "gpa1-0", "gpa1-1"; samsung,pin-function = <EXYNOS_PIN_FUNC_2>;