Defining card-detect and write-protect GPIO pins in Odroid XU SD Card
does not change anything from functional point of view - dw-mmc driver
was reading the state from registers. Adding cd-gpios and wp-gpios
properties changes only internal driver behavior to access the pins
directly.
Add them to DTS only to comprehensively describe the hardware. Minor
benefit is that write-protect pin configuration makes sure that it will
be properly pulled up to indicate write access.
This also removes debug messages:
dwmmc_exynos 12220000.mmc: No GPIO consumer cd found
dwmmc_exynos 12220000.mmc: No GPIO consumer wp found
Signed-off-by: Krzysztof Kozlowski <[email protected]>
---
arch/arm/boot/dts/exynos5410-odroidxu.dts | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/exynos5410-odroidxu.dts b/arch/arm/boot/dts/exynos5410-odroidxu.dts
index a2046f5f998c..dae360f29a47 100644
--- a/arch/arm/boot/dts/exynos5410-odroidxu.dts
+++ b/arch/arm/boot/dts/exynos5410-odroidxu.dts
@@ -525,12 +525,14 @@
&mmc_2 {
status = "okay";
+ wp-gpios = <&gpm5 0 GPIO_ACTIVE_LOW>;
+ cd-gpios = <&gpc2 2 GPIO_ACTIVE_LOW>;
card-detect-delay = <200>;
samsung,dw-mshc-ciu-div = <3>;
samsung,dw-mshc-sdr-timing = <0 4>;
samsung,dw-mshc-ddr-timing = <0 2>;
pinctrl-names = "default";
- pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4>;
+ pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4 &sd2_wp>;
bus-width = <4>;
cap-sd-highspeed;
vmmc-supply = <&ldo21_reg>;
@@ -573,6 +575,14 @@
samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
};
+
+ sd2_wp: sd2-wp {
+ samsung,pins = "gpm5-0";
+ samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
+ /* Pin is floating so pull it up to disable write-protect */
+ samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
+ samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV4>;
+ };
};
&pwm {
--
2.17.1
Hi Krzysztof,
On 2018-09-21 23:03, Krzysztof Kozlowski wrote:
> Defining card-detect and write-protect GPIO pins in Odroid XU SD Card
> does not change anything from functional point of view - dw-mmc driver
> was reading the state from registers. Adding cd-gpios and wp-gpios
> properties changes only internal driver behavior to access the pins
> directly.
>
> Add them to DTS only to comprehensively describe the hardware. Minor
> benefit is that write-protect pin configuration makes sure that it will
> be properly pulled up to indicate write access.
>
> This also removes debug messages:
> dwmmc_exynos 12220000.mmc: No GPIO consumer cd found
> dwmmc_exynos 12220000.mmc: No GPIO consumer wp found
>
> Signed-off-by: Krzysztof Kozlowski <[email protected]>
> ---
> arch/arm/boot/dts/exynos5410-odroidxu.dts | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/exynos5410-odroidxu.dts b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> index a2046f5f998c..dae360f29a47 100644
> --- a/arch/arm/boot/dts/exynos5410-odroidxu.dts
> +++ b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> @@ -525,12 +525,14 @@
>
> &mmc_2 {
> status = "okay";
> + wp-gpios = <&gpm5 0 GPIO_ACTIVE_LOW>;
> + cd-gpios = <&gpc2 2 GPIO_ACTIVE_LOW>;
> card-detect-delay = <200>;
> samsung,dw-mshc-ciu-div = <3>;
> samsung,dw-mshc-sdr-timing = <0 4>;
> samsung,dw-mshc-ddr-timing = <0 2>;
> pinctrl-names = "default";
> - pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4>;
> + pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4 &sd2_wp>;
IMHO there is no point adding cd-gpios property if CD line is already
assigned to this device via respective pin ctrl entry (as special function).
Handling of WP line is even more controversial imho. Ideally the drivers
or mmc core should check somehow if WP line is available or not and act
respectively. WP line is not available on uSD card connector so there is
no point describing it.
> bus-width = <4>;
> cap-sd-highspeed;
> vmmc-supply = <&ldo21_reg>;
> @@ -573,6 +575,14 @@
> samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
> samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
> };
> +
> + sd2_wp: sd2-wp {
> + samsung,pins = "gpm5-0";
> + samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
> + /* Pin is floating so pull it up to disable write-protect */
> + samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
> + samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV4>;
> + };
> };
>
> &pwm {
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
On Mon, Sep 24, 2018 at 12:04:52PM +0200, Marek Szyprowski wrote:
> Hi Krzysztof,
>
> On 2018-09-21 23:03, Krzysztof Kozlowski wrote:
> > Defining card-detect and write-protect GPIO pins in Odroid XU SD Card
> > does not change anything from functional point of view - dw-mmc driver
> > was reading the state from registers. Adding cd-gpios and wp-gpios
> > properties changes only internal driver behavior to access the pins
> > directly.
> >
> > Add them to DTS only to comprehensively describe the hardware. Minor
> > benefit is that write-protect pin configuration makes sure that it will
> > be properly pulled up to indicate write access.
> >
> > This also removes debug messages:
> > dwmmc_exynos 12220000.mmc: No GPIO consumer cd found
> > dwmmc_exynos 12220000.mmc: No GPIO consumer wp found
> >
> > Signed-off-by: Krzysztof Kozlowski <[email protected]>
> > ---
> > arch/arm/boot/dts/exynos5410-odroidxu.dts | 12 +++++++++++-
> > 1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/boot/dts/exynos5410-odroidxu.dts b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> > index a2046f5f998c..dae360f29a47 100644
> > --- a/arch/arm/boot/dts/exynos5410-odroidxu.dts
> > +++ b/arch/arm/boot/dts/exynos5410-odroidxu.dts
> > @@ -525,12 +525,14 @@
> >
> > &mmc_2 {
> > status = "okay";
> > + wp-gpios = <&gpm5 0 GPIO_ACTIVE_LOW>;
> > + cd-gpios = <&gpc2 2 GPIO_ACTIVE_LOW>;
> > card-detect-delay = <200>;
> > samsung,dw-mshc-ciu-div = <3>;
> > samsung,dw-mshc-sdr-timing = <0 4>;
> > samsung,dw-mshc-ddr-timing = <0 2>;
> > pinctrl-names = "default";
> > - pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4>;
> > + pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus1 &sd2_bus4 &sd2_wp>;
>
> IMHO there is no point adding cd-gpios property if CD line is already
> assigned to this device via respective pin ctrl entry (as special function).
>
> Handling of WP line is even more controversial imho. Ideally the drivers
> or mmc core should check somehow if WP line is available or not and act
> respectively. WP line is not available on uSD card connector so there is
> no point describing it.
Thanks for comments. In that case I'll add only the pin configuration to
be sure that pin stays pulled up.
Best regards,
Krzysztof
>
> > bus-width = <4>;
> > cap-sd-highspeed;
> > vmmc-supply = <&ldo21_reg>;
> > @@ -573,6 +575,14 @@
> > samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
> > samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
> > };
> > +
> > + sd2_wp: sd2-wp {
> > + samsung,pins = "gpm5-0";
> > + samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
> > + /* Pin is floating so pull it up to disable write-protect */
> > + samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
> > + samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV4>;
> > + };
> > };
> >
> > &pwm {
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>