Re: [PATCH v2 4/8] arm64: dts: mediatek: cherry: Enable secondary SD/MMC controller

From: AngeloGioacchino Del Regno
Date: Tue Jul 26 2022 - 04:11:54 EST


Il 26/07/22 06:04, Chen-Yu Tsai ha scritto:
On Mon, Jul 25, 2022 at 6:20 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:

Il 25/07/22 10:54, Chen-Yu Tsai ha scritto:
On Thu, Jul 21, 2022 at 10:51 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:

As of now, all of the boards based on the cherry platform have a
usable secondary SD/MMC controller, usually for SD cards: enable
it to allow both booting from it and generally accessing external
storage.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
.../boot/dts/mediatek/mt8195-cherry.dtsi | 62 +++++++++++++++++++
1 file changed, 62 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
index 2853f7f76c90..8859957c7b27 100644
--- a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
@@ -17,6 +17,7 @@ aliases {
i2c5 = &i2c5;
i2c7 = &i2c7;
mmc0 = &mmc0;
+ mmc1 = &mmc1;
serial0 = &uart0;
};

@@ -227,6 +228,24 @@ &mmc0 {
vqmmc-supply = <&mt6359_vufs_ldo_reg>;
};

+&mmc1 {
+ status = "okay";
+
+ bus-width = <4>;
+ cap-sd-highspeed;
+ cd-gpios = <&pio 54 GPIO_ACTIVE_LOW>;
+ max-frequency = <200000000>;
+ no-mmc;
+ no-sdio;
+ pinctrl-names = "default", "state_uhs";
+ pinctrl-0 = <&mmc1_pins_default>;
+ pinctrl-1 = <&mmc1_pins_uhs>;
+ sd-uhs-sdr50;
+ sd-uhs-sdr104;
+ vmmc-supply = <&mt_pmic_vmch_ldo_reg>;
+ vqmmc-supply = <&mt_pmic_vmc_ldo_reg>;
+};
+
/* for CPU-L */
&mt6359_vcore_buck_reg {
regulator-always-on;
@@ -575,6 +594,49 @@ pins-rst {
};
};

+ mmc1_pins_default: mmc1-default-pins {
+ pins-cmd-dat {
+ pinmux = <PINMUX_GPIO110__FUNC_MSDC1_CMD>,
+ <PINMUX_GPIO112__FUNC_MSDC1_DAT0>,
+ <PINMUX_GPIO113__FUNC_MSDC1_DAT1>,
+ <PINMUX_GPIO114__FUNC_MSDC1_DAT2>,
+ <PINMUX_GPIO115__FUNC_MSDC1_DAT3>;
+ input-enable;
+ drive-strength = <8>;
+ bias-pull-up = <MTK_PUPD_SET_R1R0_01>;
+ };
+
+ pins-clk {
+ pinmux = <PINMUX_GPIO111__FUNC_MSDC1_CLK>;
+ drive-strength = <8>;
+ bias-pull-down = <MTK_PUPD_SET_R1R0_10>;
+ };
+
+ pins-insert {
+ pinmux = <PINMUX_GPIO54__FUNC_GPIO54>;
+ bias-pull-up;
+ };
+ };
+
+ mmc1_pins_uhs: mmc1-uhs-pins {
+ pins-cmd-dat {
+ pinmux = <PINMUX_GPIO110__FUNC_MSDC1_CMD>,
+ <PINMUX_GPIO112__FUNC_MSDC1_DAT0>,
+ <PINMUX_GPIO113__FUNC_MSDC1_DAT1>,
+ <PINMUX_GPIO114__FUNC_MSDC1_DAT2>,
+ <PINMUX_GPIO115__FUNC_MSDC1_DAT3>;
+ input-enable;
+ drive-strength = <8>;
+ bias-pull-up = <MTK_PUPD_SET_R1R0_01>;
+ };
+
+ pins-clk {
+ pinmux = <PINMUX_GPIO111__FUNC_MSDC1_CLK>;
+ drive-strength = <8>;
+ bias-pull-down = <MTK_PUPD_SET_R1R0_10>;
+ };

I wonder if pins-insert should be duplicated here. And there's no
difference between the standard and UHS pinconfigs. One would expect
higher drive strength on the UHS set, if two sets were required.
So maybe we should just have one set, and use that one for both
the default and uhs states.


I don't think that it would really make a lot of sense to duplicate the
insertion pin setup in the UHS-specific pinctrl set...

Whenever you remove the uSD card, the controller goes back to default,
as the first steps in card initialization are always happening at low
speed and only after that we can switch to UHS speeds... so we do expect
that the first-ever state is always `default` (by spec!), which means
that we are also ensuring that the insertion pin setup is always done.

Right. What I wanted to say was that, besides the insertion pin, there's
no difference between the default and uhs states here. So why have two
copies instead of one that is referenced twice? (the uhs state is required
by the binding).


OH!!!! Right. Yes I definitely agree with you on that one.

Let's split the pins-insert in `mmc1_pins_det: mmc1-detect-pins` and add
a reference to it in the default pinctrl, that's a sensible option.

I'll do that for v3!

ChenYu

Cheers,
Angelo

Otherwise,

Reviewed-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>

+ };
+
nor_pins_default: nor-default-pins {
pins-ck-io {
pinmux = <PINMUX_GPIO142__FUNC_SPINOR_IO0>,
--
2.35.1





--
AngeloGioacchino Del Regno
Software Engineer

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