Re: [PATCH 3/5] Documentation: bindings: add dt documentation for rk3399 dmc

[Chanwoo Choi <cw00.choi@samsung.com>]

On 2016년 09월 02일 07:31, Lin Huang wrote:
> This patch adds the documentation for rockchip rk3399 dmc driver.
> 
> Signed-off-by: Lin Huang <hl@rock-chips.com>
> ---
> Changes in v8:
> - add ddr timing properties
> 
> Changes in v7:
> -None
> 
> 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     | 173 +++++++++++++++++++++
>  1 file changed, 173 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..1f39b5cb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
> @@ -0,0 +1,173 @@
> +* 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-dfi.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.
> +- 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.
> +- center-supply:	 DMC supply node.
> +- status:		 Marks the node enabled/disabled.
> +
> +Following properties are ddr timing:
> +
> +- dram_speed_bin :	 Value is defined at include/dt-bindings/clock/ddr.h,
> +			 it select ddr3 cl-trp-trcd type, default value
> +			 "DDR3_DEFAULT".it must selected according to
> +			 "Speed Bin" in ddr3 datasheet, DO NOT use smaller
> +			 "Speed Bin" than ddr3 exactly is.
> +
> +- pd_idle :		 Config the PD_IDLE value, defined the power-down idle
> +			 period, memories are places into power-down mode if
> +			 bus is idle for PD_IDLE DFI clocks.
> +
> +- sr_idle :		 Configure the SR_IDLE value, defined the selfrefresh
> +			 idle period, memories are places into self-refresh
> +			 mode if bus is idle for SR_IDLE*1024 DFI clocks
> +			 (DFI clocks freq is half of dram's clocks), defaule
> +			 value is "0".
> +
> +- sr_mc_gate_idle :	 Defined the self-refresh with memory and controller
> +			 clock gating idle period, memories are places into
> +			 self-refresh mode and memory controller clock arg
> +			 gating if bus is idle for sr_mc_gate_idle*1024 DFI
> +			 clocks.
> +
> +- srpd_lite_idle :	 Defined the self-refresh power down idle period,
> +			 memories are places into self-refresh power down
> +			 mode if bus is idle for srpd_lite_idle*1024 DFI
> +			 clocks. This parameter is for LPDDR4 only.
> +
> +- standby_idle :	 Defined the standby idle period, memories are places
> +			 into self-refresh than controller, pi, phy and dram
> +			 clock will gating if bus is idle for
> +			 standby_idle * DFI clocks.
> +
> +- dram_dll_disb_freq :	 It's defined the DDR3 dll bypass frequency in MHz
> +			 when ddr freq less than DRAM_DLL_DISB_FREQ, ddr3
> +			 dll will bypssed note: if dll was bypassed, the
> +			 odt also stop working.
> +
> +- phy_dll_disb_freq :	 Defined the PHY dll bypass frequency in MHz (Mega Hz),
> +			 when ddr freq less than DRAM_DLL_DISB_FREQ, phy dll
> +			 will bypssed. note: phy dll and phy odt are
> +			 independent
> +
> +- ddr3_odt_disb_freq :	 When dram type is DDR3, this parameter defined the
> +			 odt disable frequency in MHz (Mega Hz), when ddr
> +			 frequency less then ddr3_odt_disb_freq, the odt
> +			 on dram side and controller side are both disabled.
> +
> +- ddr3_drv :		 When dram type is DDR3, this parameter define the
> +			 dram side driver stength in ohm, default value is
> +			 DDR3_DS_40ohm.
> +
> +- ddr3_odt :		 When dram type is DDR3, this parameter define the
> +			 dram side ODT stength in ohm, default value is
> +			 DDR3_ODT_120ohm.
> +
> +- phy_ddr3_ca_drv :	 When dram type is DDR3, this parameter define the phy
> +			 side CA line(incluing command line, address line and
> +			 clock line) driver strength. default value is
> +			 PHY_DRV_ODT_40.
> +
> +- phy_ddr3_dq_drv :	 When dram type is DDR3, this parameter define the phy
> +			 side DQ line(incluing DQS/DQ/DM line) driver strength.
> +			 default value is PHY_DRV_ODT_40.
> +
> +- phy_ddr3_odt : 	 When dram type is DDR3, this parameter define the
> +			 phy side odt strength, default value is
> +			 PHY_DRV_ODT_240.
> +
> +- lpddr3_odt_disb_freq : When dram type is LPDDR3, this parameter defined then
> +			 odt disable frequency in MHz (Mega Hz), when ddr
> +			 frequency less then ddr3_odt_disb_freq, the odt on
> +			 dram side and controller side are both disabled.
> +
> +- lpddr3_drv :		 When dram type is LPDDR3, this parameter define the
> +			 dram side driver stength in ohm, default value is
> +			 LP3_DS_34ohm.
> +
> +- lpddr3_odt :		 When dram type is LPDDR3, this parameter define the
> +			 dram side ODT stength in ohm, default value is
> +			 LP3_ODT_240ohm.
> +
> +- phy_lpddr3_ca_drv :	 When dram type is LPDDR3, this parameter define the
> +			 phy side CA line(incluing command line, address line
> +			 and clock line) driver strength. default value is
> +			 PHY_DRV_ODT_40.
> +
> +- phy_lpddr3_dq_drv :	 When dram type is LPDDR3, this parameter define the
> +			 phy side DQ line(incluing DQS/DQ/DM line) driver
> +			 strength. default value is PHY_DRV_ODT_40.
> +
> +- phy_lpddr3_odt : 	 When dram type is LPDDR3, this parameter define the phy
> +			 side odt strength, default value is PHY_DRV_ODT_240.
> +
> +- lpddr4_odt_disb_freq : When dram type is LPDDR4, this parameter defined the
> +			 odt disable frequency in MHz (Mega Hz), when ddr
> +			 frequency less then ddr3_odt_disb_freq, the odt on
> +			 dram side and controller side are both disabled.
> +
> +- lpddr4_drv :		 When dram type is LPDDR4, this parameter define the
> +			 dram side driver stength in ohm, default value is
> +			 LP4_PDDS_60ohm.
> +
> +- lpddr4_dq_odt : 	 When dram type is LPDDR4, this parameter define the
> +			 dram side ODT on dqs/dq line stength in ohm, default
> +			 value is LP4_DQ_ODT_40ohm.
> +
> +- lpddr4_ca_odt :	 When dram type is LPDDR4, this parameter define the
> +			 dram side ODT on ca line stength in ohm, default value
> +			 is LP4_CA_ODT_40ohm.
> +
> +- phy_lpddr4_ca_drv :	 When dram type is LPDDR4, this parameter define the
> +			 phy side  CA line(incluing command address line)
> +			 driver strength. default value is PHY_DRV_ODT_40.
> +
> +- phy_lpddr4_ck_cs_drv : When dram type is LPDDR4, this parameter define the
> +			 phy side clock line and cs line driver strength.
> +			 default value is PHY_DRV_ODT_80.
> +
> +- phy_lpddr4_dq_drv :	 When dram type is LPDDR4, this parameter define the
> +			 phy side DQ line(incluing DQS/DQ/DM line) driver
> +			 strength. default value is PHY_DRV_ODT_80.
> +
> +- phy_lpddr4_odt :	 When dram type is LPDDR4, this parameter define the
> +			 phy side odt strength, default value is PHY_DRV_ODT_60.

It is good to explain the each field for ddr timing.
But, why you you drop the example for ddr timing values?
I think that you better to add the example for ddr timing values

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


-- 
Best Regards,
Chanwoo Choi