[U-Boot,4/4] rockchip: rk3188: explicitly set vcc_sd0 pin to gpio on rk3188-radxarock
diff mbox series

Message ID 20180921085948.26975-5-heiko@sntech.de
State Accepted
Commit e4d5fa3db0b9ad6551752f90b153d64706bbddef
Delegated to: Philipp Tomsich
Headers show
Series
  • rockchip: allow rk3188 to boot from mmc devices
Related show

Commit Message

Heiko Stuebner Sept. 21, 2018, 8:59 a.m. UTC
It is good practice to make the setting of gpio-pinctrls explicitly in the
devicetree, and in this case even necessary.
Rockchip boards start with iomux settings set to gpio for most pins and
while the linux pinctrl driver also implicitly sets the gpio function if
a pin is requested as gpio that is not necessarily true for other drivers.

The issue in question stems from uboot, where the sdmmc_pwr pin is set
to function 1 (sdmmc-power) by the bootrom when reading the 1st-stage
loader. The regulator controlled by the pin is active-low though, so
when the dwmmc hw-block sets its enabled bit, it actually disables the
regulator. By changing the pin back to gpio we fix that behaviour.

[picked from the identical linux patch
https://patchwork.kernel.org/patch/10609253/]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 arch/arm/dts/rk3188-radxarock.dts | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Philipp Tomsich Sept. 21, 2018, 9:15 a.m. UTC | #1
> On 21.09.2018, at 10:59, Heiko Stuebner <heiko@sntech.de> wrote:
> 
> It is good practice to make the setting of gpio-pinctrls explicitly in the
> devicetree, and in this case even necessary.
> Rockchip boards start with iomux settings set to gpio for most pins and
> while the linux pinctrl driver also implicitly sets the gpio function if
> a pin is requested as gpio that is not necessarily true for other drivers.
> 
> The issue in question stems from uboot, where the sdmmc_pwr pin is set
> to function 1 (sdmmc-power) by the bootrom when reading the 1st-stage
> loader. The regulator controlled by the pin is active-low though, so
> when the dwmmc hw-block sets its enabled bit, it actually disables the
> regulator. By changing the pin back to gpio we fix that behaviour.
> 
> [picked from the identical linux patch
> https://patchwork.kernel.org/patch/10609253/]
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Philipp Tomsich Oct. 2, 2018, 2 p.m. UTC | #2
> It is good practice to make the setting of gpio-pinctrls explicitly in the
> devicetree, and in this case even necessary.
> Rockchip boards start with iomux settings set to gpio for most pins and
> while the linux pinctrl driver also implicitly sets the gpio function if
> a pin is requested as gpio that is not necessarily true for other drivers.
> 
> The issue in question stems from uboot, where the sdmmc_pwr pin is set
> to function 1 (sdmmc-power) by the bootrom when reading the 1st-stage
> loader. The regulator controlled by the pin is active-low though, so
> when the dwmmc hw-block sets its enabled bit, it actually disables the
> regulator. By changing the pin back to gpio we fix that behaviour.
> 
> [picked from the identical linux patch
> https://patchwork.kernel.org/patch/10609253/]
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
> Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
> ---
>  arch/arm/dts/rk3188-radxarock.dts | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 

Applied to u-boot-rockchip, thanks!

Patch
diff mbox series

diff --git a/arch/arm/dts/rk3188-radxarock.dts b/arch/arm/dts/rk3188-radxarock.dts
index ac931e14af..61367126ba 100644
--- a/arch/arm/dts/rk3188-radxarock.dts
+++ b/arch/arm/dts/rk3188-radxarock.dts
@@ -104,6 +104,8 @@ 
 		regulator-min-microvolt = <3300000>;
 		regulator-max-microvolt = <3300000>;
 		gpio = <&gpio3 1 GPIO_ACTIVE_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&sdmmc_pwr>;
 		startup-delay-us = <100000>;
 		vin-supply = <&vcc_io>;
 	};
@@ -334,6 +336,12 @@ 
 		};
 	};
 
+	sd0 {
+		sdmmc_pwr: sdmmc-pwr {
+			rockchip,pins = <RK_GPIO3 1 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+
 	usb {
 		host_vbus_drv: host-vbus-drv {
 			rockchip,pins = <0 3 RK_FUNC_GPIO &pcfg_pull_none>;