DDRCTRL and DDRPHYC device tree configuration

1 Article purpose[edit]

This article explains how to configure the DDRCTRL and DDRPHYC internal peripherals from the first stage bootloader.

The configuration is performed using the device tree mechanism that provides a hardware description of the DDR subsystem (DDR controler and DDR PHY peripheral), and embeds the configuration used by the first stage bootloader to initialize the DDR before loading the second stage bootloader.

The DDR settings are only used in the device tree of the boot chain FSBL, that is, in the TF-A device tree for OpenSTLinux official delivery (or in SPL only for the DDR tuning tool).

Even if the DDR node information is also present in the U-Boot device tree, only st,mem-size is used by this SSBL.

2 DT bindings documentation[edit]

The DDR subsystem is a 'memory-controller' device represented by the device tree bindings documented below:

  • TF-A: docs/devicetree/bindings/memory-controllers/st,stm32mp1-ddr.txt"[1]
  • U-Boot: doc/device-tree-bindings/ram/st,stm32mp1-ddr.txt"[2]

3 DT configuration[edit]

This hardware description is a combination of the STM32 microprocessor device tree files (.dtsi extension) and board device tree files (.dts extension). See the Device tree for an explanation of the device-tree file split.

STM32CubeMX can be used to generate this DDR board device tree. Refer to How to configure the DT using STM32CubeMX for more details.

3.1 DT configuration (STM32 level)[edit]

The STM32MP1 DDR node is located in stm32mp15-ddr.dtsi[3] (see Device tree for further explanation).

 / {
 ...
 	soc {
 ...
 		ddr: ddr@5a003000{
   			compatible = "st,stm32mp1-ddr";
 
 			reg = <0x5A003000 0x550
 			       0x5A004000 0x234>;
 
 			clocks = <&rcc_clk AXIDCG>,
 				 <&rcc_clk DDRC1>,
 				 <&rcc_clk DDRC2>,
 				 <&rcc_clk DDRPHYC>,
 				 <&rcc_clk DDRCAPB>,
 				 <&rcc_clk DDRPHYCAPB>;
 
 			clock-names = "axidcg",
 				      "ddrc1",
 				      "ddrc2",
 				      "ddrphyc",
 				      "ddrcapb",
 				      "ddrphycapb";
 
 			status = "okay";
 		};
 	};
 };
Warning.png This device tree part is related to STM32 microprocessors. It must be kept as is, without being modified by the end user.

3.2 DT configuration (board level)[edit]

The next attributes provide the DDR information and DDR settings; the values used by the FSBL to initialize the registers of the DDR subsystem (the DDR controller and the DDR PHY).

These value are generated by DDR tools included in STM32CubeMX.

3.2.1 info[edit]

  • st,mem-name: name for the DDR configuration, a simple string for information
  • st,mem-speed: DDR expected speed in kHz
  • st,mem-size: DDR mem size in bytes (used in SSBL and FSBL)

3.2.2 Controller register values[edit]

  • st,ctl-reg: controller values depending on the DDR type (DDR3/LPDDR2/LPDDR3):
    • for STM32MP15x lines More info.png 25 values are requested in this order: (MSTR MRCTRL0 MRCTRL1 DERATEEN DERATEINT PWRCTL PWRTMG HWLPCTL RFSHCTL0 RFSHCTL3 CRCPARCTL0 ZQCTL0 DFITMG0 DFITMG1 DFILPCFG0 DFIUPD0 DFIUPD1 DFIUPD2 DFIPHYMSTR ODTMAP DBG0 DBG1 DBGCMD POISONCFG PCCFG)
  • st,ctl-timing: controller values depending on the DDR frequency and timing parameters:
    • for STM32MP15x lines More info.png 12 values are requested in this order: (RFSHTMG DRAMTMG0 DRAMTMG1 DRAMTMG2 DRAMTMG3 DRAMTMG4 DRAMTMG5 DRAMTMG6 DRAMTMG7 DRAMTMG8 DRAMTMG14 ODTCFG)
  • st,ctl-map: controller values depending on the address mapping:
    • for STM32MP15x lines More info.png 9 values are requested in this order: (ADDRMAP1 ADDRMAP2 ADDRMAP3 ADDRMAP4 ADDRMAP5 ADDRMAP6 ADDRMAP9 ADDRMAP10 ADDRMAP11)
  • st,ctl-perf: controller values depending on performance and scheduling:
    • for STM32MP15x lines More info.png 17 values are requested in this order: (SCHED SCHED1 PERFHPR1 PERFLPR1 PERFWR1 PCFGR_0 PCFGW_0 PCFGQOS0_0 PCFGQOS1_0 PCFGWQOS0_0 PCFGWQOS1_0 PCFGR_1 PCFGW_1 PCFGQOS0_1 PCFGQOS1_1 PCFGWQOS0_1 PCFGWQOS1_1)

3.2.3 phy register values[edit]

  • st,phy-reg: phy values depending on the DDR type: (DDR3/LPDDR2/LPDDR3):
    • for STM32MP15x lines More info.png 11 values are requested in this order: (PGCR ACIOCR DXCCR DSGCR DCR ODTCR ZQ0CR1 DX0GCR DX1GCR DX2GCR DX3GCR)
  • st,phy-timing: phy values depending on the DDR frequency and timing parameters:
    • for STM32MP15x lines More info.png 10 values are requested in this order: (PTR0 PTR1 PTR2 DTPR0 DTPR1 DTPR2 MR0 MR1 MR2 MR3)
  • st,phy-cal: phy cal depending on the DDR calibration or tuning:
    • for STM32MP15x lines More info.png 12 values are requested in this order: (DX0DLLCR DX0DQTR DX0DQSTR DX1DLLCR DX1DQTR DX1DQSTR DX2DLLCR DX2DQTR DX2DQSTR DX3DLLCR DX3DQTR DX3DQSTR)

The board configuration defines each configuration needed (DDR_...) and includes the STM32-level device tree.

3.3 DT configuration examples[edit]

3.3.1 Simple example[edit]

You can add the DDR configuration node with :

  / {
  ...
  	soc {
  		ddr: ddr@5a003000{
    			compatible = "st,stm32mp1-ddr";
  
  			reg = <0x5A003000 0x550
  			       0x5A004000 0x234>;
  
  			clocks = <&rcc_clk AXIDCG>,
  				 <&rcc_clk DDRC1>,
  				 <&rcc_clk DDRC2>,
  				 <&rcc_clk DDRPHYC>,
  				 <&rcc_clk DDRCAPB>,
  				 <&rcc_clk DDRPHYCAPB>;
  
  			clock-names = "axidcg",
  				      "ddrc1",
  				      "ddrc2",
  				      "ddrphyc",
  				      "ddrcapb",
  				      "ddrphycapb";
  
  			st,mem-name = "DDR3 2x4Gb 533MHz";
  			st,mem-speed = <533000>;
  			st,mem-size = <0x40000000>;
  
  			st,ctl-reg = <
  				0x00040401 /*MSTR*/
  				0x00000010 /*MRCTRL0*/
  				0x00000000 /*MRCTRL1*/
  				0x00000000 /*DERATEEN*/
  				0x00800000 /*DERATEINT*/
  				0x00000000 /*PWRCTL*/
  				0x00400010 /*PWRTMG*/
  				0x00000000 /*HWLPCTL*/
  				0x00210000 /*RFSHCTL0*/
  				0x00000000 /*RFSHCTL3*/
  				0x00000000 /*CRCPARCTL0*/
  				0xC2000040 /*ZQCTL0*/
  				0x02050105 /*DFITMG0*/
  				0x00000202 /*DFITMG1*/
  				0x07000000 /*DFILPCFG0*/
  				0xC0400003 /*DFIUPD0*/
  				0x00000000 /*DFIUPD1*/
  				0x00000000 /*DFIUPD2*/
  				0x00000000 /*DFIPHYMSTR*/
  				0x00000001 /*ODTMAP*/
  				0x00000000 /*DBG0*/
  				0x00000000 /*DBG1*/
  				0x00000000 /*DBGCMD*/
  				0x00000000 /*POISONCFG*/
  				0x00000010 /*PCCFG*/
  			>;
  
  			st,ctl-timing = <
  				0x0080008A /*RFSHTMG*/
  				0x121B2414 /*DRAMTMG0*/
  				0x000D041B /*DRAMTMG1*/
  				0x0607080E /*DRAMTMG2*/
  				0x0050400C /*DRAMTMG3*/
  				0x07040407 /*DRAMTMG4*/
  				0x06060303 /*DRAMTMG5*/
  				0x02020002 /*DRAMTMG6*/
  				0x00000202 /*DRAMTMG7*/
  				0x00001005 /*DRAMTMG8*/
  				0x000D041B /*DRAMTMG14*/
  				0x06000600 /*ODTCFG*/
  			>;
  
  			st,ctl-map = <
  				0x00080808 /*ADDRMAP1*/
  				0x00000000 /*ADDRMAP2*/
  				0x00000000 /*ADDRMAP3*/
  				0x00001F1F /*ADDRMAP4*/
  				0x07070707 /*ADDRMAP5*/
  				0x0F070707 /*ADDRMAP6*/
  				0x00000000 /*ADDRMAP9*/
  				0x00000000 /*ADDRMAP10*/
  				0x00000000 /*ADDRMAP11*/
  			>;
  
  			st,ctl-perf = <
  				0x00001201 /*SCHED*/
  				0x00001201 /*SCHED*/1
  				0x01000001 /*PERFHPR1*/
  				0x08000200 /*PERFLPR1*/
  				0x08000400 /*PERFWR1*/
  				0x00010000 /*PCFGR_0*/
  				0x00000000 /*PCFGW_0*/
  				0x02100B03 /*PCFGQOS0_0*/
  				0x00800100 /*PCFGQOS1_0*/
  				0x01100B03 /*PCFGWQOS0_0*/
  				0x01000200 /*PCFGWQOS1_0*/
  				0x00010000 /*PCFGR_1*/
  				0x00000000 /*PCFGW_1*/
  				0x02100B03 /*PCFGQOS0_1*/
  				0x00800000 /*PCFGQOS1_1*/
  				0x01100B03 /*PCFGWQOS0_1*/
  				0x01000200 /*PCFGWQOS1_1*/
  			>;
  
  			st,phy-reg = <
  				0x01442E02 /*PGCR*/
  				0x10400812 /*ACIOCR*/
  				0x00000C40 /*DXCCR*/
  				0xF200001F /*DSGCR*/
  				0x0000000B /*DCR*/
  				0x00010000 /*ODTCR*/
  				0x0000007B /*ZQ0CR1*/
  				0x0000CE81 /*DX0GCR*/
  				0x0000CE81 /*DX1GCR*/
  				0x0000CE81 /*DX2GCR*/
  				0x0000CE81 /*DX3GCR*/
  			>;
  
  			st,phy-timing = <
  				0x0022A41B /*PTR0*/
  				0x047C0740 /*PTR1*/
  				0x042D9C80 /*PTR2*/
  				0x369477D0 /*DTPR0*/
  				0x098A00D8 /*DTPR1*/
  				0x10023600 /*DTPR2*/
  				0x00000830 /*MR0*/
  				0x00000000 /*MR1*/
  				0x00000208 /*MR2*/
  				0x00000000 /*MR3*/
  			>;
  
  			st,phy-cal = <
  				0x40000000 /*DX0DLLCR*/
  				0xFFFFFFFF /*DX0DQTR*/
  				0x3DB02000 /*DX0DQSTR*/
  				0x40000000 /*DX1DLLCR*/
  				0xFFFFFFFF /*DX1DQTR*/
  				0x3DB02000 /*DX1DQSTR*/
  				0x40000000 /*DX2DLLCR*/
  				0xFFFFFFFF /*DX2DQTR*/
  				0x3DB02000 /*DX2DQSTR*/
  				0x40000000 /*DX3DLLCR*/
  				0xFFFFFFFF /*DX3DQTR*/
  				0x3DB02000 /*DX3DQSTR*/
  			>;
  
  			status = "okay";
        };

3.3.2 STM32CubeMX configuration file[edit]

STM32CubeMX generates a .dtsi file with the needed values as defines (named DDR_...), and includes the #Generic DDR dtsi file "stm32mp15-ddr.dtsi"[3]: as this dtsi file is preprocessed during FSBL compilation, it generates a correct device tree.

For example the file fdts/stm32mp15-ddr3-1x4Gb-1066-binG.dtsi is:

  #define DDR_MEM_NAME "DDR3-1066/888 bin G 1x4Gb 533MHz v1.45"
  #define DDR_MEM_SPEED 533000
  #define DDR_MEM_SIZE 0x20000000
 
  #define DDR_MSTR 0x00041401
  #define DDR_MRCTRL0 0x00000010
  #define DDR_MRCTRL1 0x00000000
  #define DDR_DERATEEN 0x00000000
  #define DDR_DERATEINT 0x00800000
  .....
  #define DDR_DX2DQSTR 0x3DB02000
  #define DDR_DX3GCR 0x0000CE80
  #define DDR_DX3DLLCR 0x40000000
  #define DDR_DX3DQTR 0xFFFFFFFF
  #define DDR_DX3DQSTR 0x3DB02000
  
  #include "stm32mp15-ddr.dtsi"

3.3.3 Generic DDR dtsi file[edit]

The dtsi file used with DDR_ defines for STM32MP15x lines More info.png is stm32mp15-ddr.dtsi

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
 * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
 */

/ {
	soc {
		ddr: ddr@5a003000{

			compatible = "st,stm32mp1-ddr";

			reg = <0x5A003000 0x550
			       0x5A004000 0x234>;

			clocks = <&rcc AXIDCG>,
				 <&rcc DDRC1>,
				 <&rcc DDRC2>,
				 <&rcc DDRPHYC>,
				 <&rcc DDRCAPB>,
				 <&rcc DDRPHYCAPB>;

			clock-names = "axidcg",
				      "ddrc1",
				      "ddrc2",
				      "ddrphyc",
				      "ddrcapb",
				      "ddrphycapb";

			st,mem-name = DDR_MEM_NAME;
			st,mem-speed = <DDR_MEM_SPEED>;
			st,mem-size = <DDR_MEM_SIZE>;

			st,ctl-reg = <
				DDR_MSTR
				DDR_MRCTRL0
				DDR_MRCTRL1
				DDR_DERATEEN
				DDR_DERATEINT
				DDR_PWRCTL
				DDR_PWRTMG
				DDR_HWLPCTL
				DDR_RFSHCTL0
				DDR_RFSHCTL3
				DDR_CRCPARCTL0
				DDR_ZQCTL0
				DDR_DFITMG0
				DDR_DFITMG1
				DDR_DFILPCFG0
				DDR_DFIUPD0
				DDR_DFIUPD1
				DDR_DFIUPD2
				DDR_DFIPHYMSTR
				DDR_ODTMAP
				DDR_DBG0
				DDR_DBG1
				DDR_DBGCMD
				DDR_POISONCFG
				DDR_PCCFG
			>;

			st,ctl-timing = <
				DDR_RFSHTMG
				DDR_DRAMTMG0
				DDR_DRAMTMG1
				DDR_DRAMTMG2
				DDR_DRAMTMG3
				DDR_DRAMTMG4
				DDR_DRAMTMG5
				DDR_DRAMTMG6
				DDR_DRAMTMG7
				DDR_DRAMTMG8
				DDR_DRAMTMG14
				DDR_ODTCFG
			>;

			st,ctl-map = <
				DDR_ADDRMAP1
				DDR_ADDRMAP2
				DDR_ADDRMAP3
				DDR_ADDRMAP4
				DDR_ADDRMAP5
				DDR_ADDRMAP6
				DDR_ADDRMAP9
				DDR_ADDRMAP10
				DDR_ADDRMAP11
			>;

			st,ctl-perf = <
				DDR_SCHED
				DDR_SCHED1
				DDR_PERFHPR1
				DDR_PERFLPR1
				DDR_PERFWR1
				DDR_PCFGR_0
				DDR_PCFGW_0
				DDR_PCFGQOS0_0
				DDR_PCFGQOS1_0
				DDR_PCFGWQOS0_0
				DDR_PCFGWQOS1_0
				DDR_PCFGR_1
				DDR_PCFGW_1
				DDR_PCFGQOS0_1
				DDR_PCFGQOS1_1
				DDR_PCFGWQOS0_1
				DDR_PCFGWQOS1_1
			>;

			st,phy-reg = <
				DDR_PGCR
				DDR_ACIOCR
				DDR_DXCCR
				DDR_DSGCR
				DDR_DCR
				DDR_ODTCR
				DDR_ZQ0CR1
				DDR_DX0GCR
				DDR_DX1GCR
				DDR_DX2GCR
				DDR_DX3GCR
			>;

			st,phy-timing = <
				DDR_PTR0
				DDR_PTR1
				DDR_PTR2
				DDR_DTPR0
				DDR_DTPR1
				DDR_DTPR2
				DDR_MR0
				DDR_MR1
				DDR_MR2
				DDR_MR3
			>;

			st,phy-cal = <
				DDR_DX0DLLCR
				DDR_DX0DQTR
				DDR_DX0DQSTR
				DDR_DX1DLLCR
				DDR_DX1DQTR
				DDR_DX1DQSTR
				DDR_DX2DLLCR
				DDR_DX2DQTR
				DDR_DX2DQSTR
				DDR_DX3DLLCR
				DDR_DX3DQTR
				DDR_DX3DQSTR
			>;

			status = "okay";
		};
	};
};

4 How to configure the DT using STM32CubeMX[edit]

The STM32CubeMX tool can be used to configure the STM32MPU device and get the corresponding platform configuration device tree files.

The STM32CubeMX supports all the defines described in the above DT bindings documentation paragraph with a generated included file "stm32mp15-mx.h"; it is included in the mx dts file before the #Generic DDR dtsi file . Refer to the STM32CubeMX user manual and the dedicated application note[4] for further information.

See also How_to_create_your_board_device_tree#DDR configuration with STM32CubeMX DDR Tuning Tool.

5 References[edit]

Please refer to the following links for additional information:



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