2023-06-07 21:38:57

by Dmitry Rokosov

[permalink] [raw]
Subject: [PATCH v1 6/6] arm64: dts: meson: a1: add eMMC controller and its pins

From: Jan Dakinevich <[email protected]>

The definition is inspired by a similar one for AXG SoC family.
'sdio_pins' and 'sdio_clk_gate_pins' pinctrls are supposed to be used as
"default" and "clk-gate" in board-specific device trees.

'meson-gx' driver during initialization sets clock to safe low-frequency
value (400kHz). However, both source clocks ("clkin0" and "clkin1") are
high-frequency by default, and using of eMMC's internal divider is not
enough to achieve so low values. To provide low-frequency source,
reparent "sd_emmc_sel2" clock using 'assigned-clocks' property.

Signed-off-by: Jan Dakinevich <[email protected]>
Signed-off-by: Dmitry Rokosov <[email protected]>
---
arch/arm64/boot/dts/amlogic/meson-a1.dtsi | 43 +++++++++++++++++++++++
1 file changed, 43 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
index 3eb6aa9c00e0..a25170c61462 100644
--- a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
@@ -134,6 +134,32 @@ mux {
bias-pull-down;
};
};
+
+ sdio_pins: sdio {
+ mux-0 {
+ groups = "sdcard_d0_x",
+ "sdcard_d1_x",
+ "sdcard_d2_x",
+ "sdcard_d3_x",
+ "sdcard_cmd_x";
+ function = "sdcard";
+ bias-pull-up;
+ };
+
+ mux-1 {
+ groups = "sdcard_clk_x";
+ function = "sdcard";
+ bias-disable;
+ };
+ };
+
+ sdio_clk_gate_pins: sdio_clk_gate {
+ mux {
+ groups = "sdcard_clk_x";
+ function = "sdcard";
+ bias-pull-down;
+ };
+ };
};

uart_AO: serial@1c00 {
@@ -200,6 +226,23 @@ usb2_phy1: phy@4000 {
#phy-cells = <0>;
power-domains = <&pwrc PWRC_USB_ID>;
};
+
+ sd_emmc: sd@10000 {
+ compatible = "amlogic,meson-axg-mmc";
+ reg = <0x0 0x10000 0x0 0x800>;
+ interrupts = <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clkc_periphs CLKID_SD_EMMC_A>,
+ <&clkc_periphs CLKID_SD_EMMC>,
+ <&clkc_pll CLKID_FCLK_DIV2>;
+ clock-names = "core",
+ "clkin0",
+ "clkin1";
+ assigned-clocks = <&clkc_periphs CLKID_SD_EMMC_SEL2>;
+ assigned-clock-parents = <&xtal>;
+ resets = <&reset RESET_SD_EMMC_A>;
+ power-domains = <&pwrc PWRC_SD_EMMC_ID>;
+ status = "disabled";
+ };
};

gic: interrupt-controller@ff901000 {
--
2.36.0



2023-06-25 21:26:20

by Martin Blumenstingl

[permalink] [raw]
Subject: Re: [PATCH v1 6/6] arm64: dts: meson: a1: add eMMC controller and its pins

On Wed, Jun 7, 2023 at 10:16 PM Dmitry Rokosov <[email protected]> wrote:
>
> From: Jan Dakinevich <[email protected]>
>
> The definition is inspired by a similar one for AXG SoC family.
> 'sdio_pins' and 'sdio_clk_gate_pins' pinctrls are supposed to be used as
> "default" and "clk-gate" in board-specific device trees.
Let's wait for Neil's response on the other patch for the question
about pin mux settings

> 'meson-gx' driver during initialization sets clock to safe low-frequency
> value (400kHz). However, both source clocks ("clkin0" and "clkin1") are
> high-frequency by default, and using of eMMC's internal divider is not
> enough to achieve so low values. To provide low-frequency source,
> reparent "sd_emmc_sel2" clock using 'assigned-clocks' property.
Even if the pinctrl part should be postponed then I think it's worth
adding &sd_emmc

2023-06-26 13:51:14

by Neil Armstrong

[permalink] [raw]
Subject: Re: [PATCH v1 6/6] arm64: dts: meson: a1: add eMMC controller and its pins

Hi,

On 25/06/2023 23:11, Martin Blumenstingl wrote:
> On Wed, Jun 7, 2023 at 10:16 PM Dmitry Rokosov <[email protected]> wrote:
>>
>> From: Jan Dakinevich <[email protected]>
>>
>> The definition is inspired by a similar one for AXG SoC family.
>> 'sdio_pins' and 'sdio_clk_gate_pins' pinctrls are supposed to be used as
>> "default" and "clk-gate" in board-specific device trees.
> Let's wait for Neil's response on the other patch for the question
> about pin mux settings
>
>> 'meson-gx' driver during initialization sets clock to safe low-frequency
>> value (400kHz). However, both source clocks ("clkin0" and "clkin1") are
>> high-frequency by default, and using of eMMC's internal divider is not
>> enough to achieve so low values. To provide low-frequency source,
>> reparent "sd_emmc_sel2" clock using 'assigned-clocks' property.
> Even if the pinctrl part should be postponed then I think it's worth
> adding &sd_emmc

Yeah it's weird to add HW definition and to not enable them,
so please enable them in the board if you add them in the DTSI.

Neil

2023-06-28 14:52:16

by Dmitry Rokosov

[permalink] [raw]
Subject: Re: [PATCH v1 6/6] arm64: dts: meson: a1: add eMMC controller and its pins

Hello Neil,

Thank you for the review!

On Mon, Jun 26, 2023 at 03:36:23PM +0200, [email protected] wrote:
> Hi,
>
> On 25/06/2023 23:11, Martin Blumenstingl wrote:
> > On Wed, Jun 7, 2023 at 10:16 PM Dmitry Rokosov <[email protected]> wrote:
> > >
> > > From: Jan Dakinevich <[email protected]>
> > >
> > > The definition is inspired by a similar one for AXG SoC family.
> > > 'sdio_pins' and 'sdio_clk_gate_pins' pinctrls are supposed to be used as
> > > "default" and "clk-gate" in board-specific device trees.
> > Let's wait for Neil's response on the other patch for the question
> > about pin mux settings
> >
> > > 'meson-gx' driver during initialization sets clock to safe low-frequency
> > > value (400kHz). However, both source clocks ("clkin0" and "clkin1") are
> > > high-frequency by default, and using of eMMC's internal divider is not
> > > enough to achieve so low values. To provide low-frequency source,
> > > reparent "sd_emmc_sel2" clock using 'assigned-clocks' property.
> > Even if the pinctrl part should be postponed then I think it's worth
> > adding &sd_emmc
>
> Yeah it's weird to add HW definition and to not enable them,
> so please enable them in the board if you add them in the DTSI.

Unfortunately, I'm unable to provide our internal board DTS. However, I
have an AD401 reference board on hand, so it's possible to test
everything there. I'll include these changes in the next version.

--
Thank you,
Dmitry