Re: [PATCH v6 6/8] Documentation: bindings: add dt documentation for rk3399 dmc

Chanwoo Choi
2016-08-17T04:50:30Z

Hi Lin,

On 2016년 08월 17일 07:36, Lin Huang wrote:
> This patch adds the documentation for rockchip rk3399 dmc driver.
>
> Signed-off-by: Lin Huang <hl@rock-chips.com>
> ---
> Changes in v6:
> -Add more detail in Documentation
>
> Changes in v5:
> -None
>
> Changes in v4:
> -None
>
> Changes in v3:
> -None
>
> Changes in v2:
> -None
>
> Changes in v1:
> -None
> .../devicetree/bindings/devfreq/rk3399_dmc.txt | 84 ++++++++++++++++++++++
> 1 file changed, 84 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
>
> diff --git a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
> new file mode 100644
> index 0000000..e73067c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
> @@ -0,0 +1,84 @@
> +* Rockchip rk3399 DMC(Dynamic Memory Controller) device
> +
> +Required properties:
> +- compatible: Must be "rockchip,rk3399-dmc".
> +- devfreq-events: Node to get ddr loading, Refer to
> + Documentation/devicetree/bindings/devfreq/rockchip-dif.txt
> +- interrupts: The interrupt number to the cpu. The interrupt specifier format
> + depends on the interrupt controller. it should be dcf interrupts,
> + when ddr dvfs finish, it will happen.

If possible, you better to keep the indentation with other properties.
s/it->It, dcf->DCF, ddr->DDR

> +- clocks: Phandles for clock specified in "clock-names" property
> +- clock-names : The name of clock used by the DFI, must be "pclk_ddr_mon";
> +- operating-points-v2: Refer to Documentation/devicetree/bindings/power/opp.txt
> + for details.

ditto.

> +- center-supply: Dmc supply node.

s/Dmc/DMC becaue DMC an abbreviation.

> +- status: Marks the node enabled/disabled.
> +
> +Optional properties:
> +- ddr_timing: ddr timing need to pass to arm trust firmware
> +- upthreshold: the upthreshold to simpleondeamnd policy
> +- downdifferential: The downdifferential to simpleondeamnd policy
> +
> +Example:
> + ddr_timing: ddr_timing {
> + compatible = "rockchip,ddr-timing";

I can't find the 'rockchip,ddr-timing' driver on linux-next git repo (20160816).
If ddr_timing includes the only properties for ddr_timing,
I recommend you make the separate a .dtsi file including
the ddr timing configuration. I add the reference and an example on below.

> + ddr3_speed_bin = <21>;
> + pd_idle = <0>;
> + sr_idle = <0>;
> + sr_mc_gate_idle = <0>;
> + srpd_lite_idle = <0>;
> + standby_idle = <0>;
> + dram_dll_dis_freq = <300>;
> + phy_dll_dis_freq = <125>;
> +
> + ddr3_odt_dis_freq = <333>;
> + ddr3_drv = <DDR3_DS_40ohm>;
> + ddr3_odt = <DDR3_ODT_120ohm>;
> + phy_ddr3_ca_drv = <PHY_DRV_ODT_40>;
> + phy_ddr3_dq_drv = <PHY_DRV_ODT_40>;
> + phy_ddr3_odt = <PHY_DRV_ODT_240>;
> +
> + lpddr3_odt_dis_freq = <333>;
> + lpddr3_drv = <LP3_DS_34ohm>;
> + lpddr3_odt = <LP3_ODT_240ohm>;
> + phy_lpddr3_ca_drv = <PHY_DRV_ODT_40>;
> + phy_lpddr3_dq_drv = <PHY_DRV_ODT_40>;
> + phy_lpddr3_odt = <PHY_DRV_ODT_240>;
> +
> + lpddr4_odt_dis_freq = <333>;
> + lpddr4_drv = <LP4_PDDS_60ohm>;
> + lpddr4_dq_odt = <LP4_DQ_ODT_40ohm>;
> + lpddr4_ca_odt = <LP4_CA_ODT_40ohm>;
> + phy_lpddr4_ca_drv = <PHY_DRV_ODT_40>;
> + phy_lpddr4_ck_cs_drv = <PHY_DRV_ODT_80>;
> + phy_lpddr4_dq_drv = <PHY_DRV_ODT_80>;
> + phy_lpddr4_odt = <PHY_DRV_ODT_60>;
> + };
> +
> + dmc_opp_table: dmc_opp_table {
> + compatible = "operating-points-v2";
> +
> + opp00 {
> + opp-hz = /bits/ 64 <300000000>;
> + opp-microvolt = <900000>;
> + };
> + opp01 {
> + opp-hz = /bits/ 64 <666000000>;
> + opp-microvolt = <900000>;
> + };
> + };
> +
> + dmc: dmc {
> + compatible = "rockchip,rk3399-dmc";
> + devfreq-events = <&dfi>;
> + interrupts = <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&cru SCLK_DDRCLK>;
> + clock-names = "dmc_clk";
> + ddr_timing = <&ddr_timing>;

You can use the following '#include' instead of 'ddr_timing'
because the ddr_timing is not a device driver. Instead,
the rk3399-dmc must need the ddr timing configuration.

#include "rk3399-dmc-timing-conf.dtsi"

You can refer the similar usage case[1].
The *.conf.dtsi is used on exynos3250 tmu dt node[2].

[1] arch/arm/boot/dts/exynos4412-tmu-sensor-conf.dtsi
[2] arch/arm/boot/dts/exynos3250.dtsi, 224 line.

> + operating-points-v2 = <&dmc_opp_table>;
> + center-supply = <&ppvar_centerlogic>;
> + upthreshold = <15>;
> + downdifferential = <10>;
> + status = "disabled";
> + };
> +
>

For example,
I think that you can add the following timing .dtsi file.
- arch/arm/boot/dts/rk3399-dmc-timing-conf.dtsi

/*
* Device tree sources for RK3399 DDR timing configuration
*
* Copyright (c) 2016 Lin Huang <hl@rock-chips.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/

rockchip,ddr3_speed_bin = <21>;
rockchip,pd_idle = <0>;
rockchip,sr_idle = <0>;
rockchip,sr_mc_gate_idle = <0>;
rockchip,srpd_lite_idle = <0>;
rockchip,standby_idle = <0>;
rockchip,dram_dll_dis_freq = <300>;
rockchip,phy_dll_dis_freq = <125>;

rockchip,ddr3_odt_dis_freq = <333>;
rockchip,ddr3_drv = <DDR3_DS_40ohm>;
rockchip,ddr3_odt = <DDR3_ODT_120ohm>;
rockchip,phy_ddr3_ca_drv = <PHY_DRV_ODT_40>;
rockchip,phy_ddr3_dq_drv = <PHY_DRV_ODT_40>;
rockchip,phy_ddr3_odt = <PHY_DRV_ODT_240>;

rockchip,lpddr3_odt_dis_freq = <333>;
rockchip,lpddr3_drv = <LP3_DS_34ohm>;
rockchip,lpddr3_odt = <LP3_ODT_240ohm>;
rockchip,phy_lpddr3_ca_drv = <PHY_DRV_ODT_40>;
rockchip,phy_lpddr3_dq_drv = <PHY_DRV_ODT_40>;
rockchip,phy_lpddr3_odt = <PHY_DRV_ODT_240>;

rockchip,lpddr4_odt_dis_freq = <333>;
rockchip,lpddr4_drv = <LP4_PDDS_60ohm>;
rockchip,lpddr4_dq_odt = <LP4_DQ_ODT_40ohm>;
rockchip,lpddr4_ca_odt = <LP4_CA_ODT_40ohm>;
rockchip,phy_lpddr4_ca_drv = <PHY_DRV_ODT_40>;
rockchip,phy_lpddr4_ck_cs_drv = <PHY_DRV_ODT_80>;
rockchip,phy_lpddr4_dq_drv = <PHY_DRV_ODT_80>;
rockchip,phy_lpddr4_odt = <PHY_DRV_ODT_60>;

Regards,
Chanwoo Choi