1. Article purpose[edit source]
This article explains how to configure the HDP driver when the peripheral is assigned to the Linux® OS.
The configuration is performed using the device tree mechanism, which provides a hardware description of the Ethernet peripheral used by STM32 HDP driver
2. DT bindings documentation[edit source]
The HDP tree bindings are composed of:
- STM32 HDP device tree bindings [1]
3. DT configuration[edit source]
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 the board device tree. Refer to How to configure the DT using STM32CubeMX for more details.
3.1. DT configuration (STM32 level)[edit source]
The HDP node is described in the stm32mp157c.dtsi [2] file with disabled status and required properties such as:
- The physical base address and size of the device register map
- The HDP clock
hdp: hdp@5002a000 {
compatible = "st,stm32mp1-hdp";
reg = <0x5002a000 0x400>;
clocks = <&rcc HDP>;
clock-names = "hdp";
status = "disabled";
};
The required and optional properties are fully described in the bindings files.
3.2. HDP DT configuration (board level)[edit source]
Part of the device tree describes the HDP hardware used on a given board. The DT node ("hdp") must be filled in as follows:
- Enable the HDP block by setting status = "okay".
- Configure the pins in use via pinctrl, through pinctrl-0 (default pins), pinctrl-1 (sleep pins) and pinctrl-names.
- Configure the HDP interface using muxing-hdp to indicate which one of the 16 possible output pins is assigned to each HDP output.
&hdp {
pinctrl-names = "default", "sleep";
pinctrl-0 = <&hdpx_pins_y>;
pinctrl-1 = <&hdpx_pins_sleep_y>;
status = "disabled";
muxing-hdp = <(STM32_HDP(x, HDPx_value))>;
};
3.3. DT configuration examples[edit source]
The example below shows how to configure and enable HDP instances at board level:
&hdp {
pinctrl-names = "default", "sleep";
pinctrl-0 = <&hdp0_pins_a &hdp6_pins_a &hdp7_pins_a>; /* configure pinctrl for hdp pin 0, 6 and 7*/
pinctrl-1 = <&hdp0_pins_sleep_a &hdp6_pins_sleep_a &hdp7_pins_sleep_a>;
status = "okay"; /* enable HDP */
muxing-hdp = <(STM32_HDP(0, HDP0_GPOVAL_0) | /* For HDP pin 0, the signal HDP0_GPOVAL_0 is selected*/
STM32_HDP(6, HDP6_GPOVAL_6) | /* For HDP pin 6, the signal HDP0_GPOVAL_6 is selected*/
STM32_HDP(7, HDP7_GPOVAL_7))>; /* For HDP pin 7, the signal HDP0_GPOVAL_7 is selected*/
};
List of all possible HDP signals:
/* define HDP Pins number*/ HDP0_PWR_PWRWAKE_SYS HDP0_CM4_SLEEPDEEP HDP0_PWR_STDBY_WKUP HDP0_PWR_ENCOMP_VDDCORE HDP0_BSEC_OUT_SEC_NIDEN HDP0_RCC_CM4_SLEEPDEEP HDP0_GPU_DBG7 HDP0_DDRCTRL_LP_REQ HDP0_PWR_DDR_RET_ENABLE_N HDP0_GPOVAL_0 HDP1_PWR_PWRWAKE_MCU HDP1_CM4_HALTED HDP1_CA7_NAXIERRIRQ HDP1_PWR_OKIN_MR HDP1_BSEC_OUT_SEC_DBGEN HDP1_EXTI_SYS_WAKEUP HDP1_RCC_PWRDS_MPU HDP1_GPU_DBG6 HDP1_DDRCTRL_DFI_CTRLUPD_REQ HDP1_DDRCTRL_CACTIVE_DDRC_ASR HDP1_GPOVAL_1 HDP2_PWR_PWRWAKE_MPU HDP2_CM4_RXEV HDP2_CA7_NPMUIRQ1 HDP2_CA7_NFIQOUT1 HDP2_BSEC_IN_RSTCORE_N HDP2_EXTI_C2_WAKEUP HDP2_RCC_PWRDS_MCU HDP2_GPU_DBG5 HDP2_DDRCTRL_DFI_INIT_COMPLETE HDP2_DDRCTRL_PERF_OP_IS_REFRESH HDP2_DDRCTRL_GSKP_DFI_LP_REQ HDP2_GPOVAL_2 HDP3_PWR_SEL_VTH_VDD_CORE HDP3_CM4_TXEV HDP3_CA7_NPMUIRQ0 HDP3_CA7_NFIQOUT0 HDP3_BSEC_OUT_SEC_DFTLOCK HDP3_EXTI_C1_WAKEUP HDP3_RCC_PWRDS_SYS HDP3_GPU_DBG4 HDP3_DDRCTRL_STAT_DDRC_REG_SELREF_TYPE0 HDP3_DDRCTRL_CACTIVE_1 HDP3_GPOVAL_3 HDP4_PWR_PDDS HDP4_CM4_SLEEPING HDP4_CA7_NRESET1 HDP4_CA7_NIRQOUT1 HDP4_BSEC_OUT_SEC_DFTEN HDP4_BSEC_OUT_SEC_DBGSWENABLE HDP4_ETH_OUT_PMT_INTR_O HDP4_GPU_DBG3 HDP4_DDRCTRL_STAT_DDRC_REG_SELREF_TYPE1 HDP4_DDRCTRL_CACTIVE_0 HDP4_GPOVAL_4 HDP5_CA7_STANDBYWFIL2 HDP5_PWR_VTH_VDDCORE_ACK HDP5_CA7_NRESET0 HDP5_CA7_NIRQOUT0 HDP5_BSEC_IN_PWROK HDP5_BSEC_OUT_SEC_DEVICEEN HDP5_ETH_OUT_LPI_INTR_O HDP5_GPU_DBG2 HDP5_DDRCTRL_CACTIVE_DDRC HDP5_DDRCTRL_WR_CREDIT_CNT HDP5_GPOVAL_5 HDP6_CA7_STANDBYWFI1 HDP6_CA7_STANDBYWFE1 HDP6_CA7_EVENT0 HDP6_CA7_DBGACK1 HDP6_BSEC_OUT_SEC_SPNIDEN HDP6_ETH_OUT_MAC_SPEED_O1 HDP6_GPU_DBG1 HDP6_DDRCTRL_CSYSACK_DDRC HDP6_DDRCTRL_LPR_CREDIT_CNT HDP6_GPOVAL_6 HDP7_CA7_STANDBYWFI0 HDP7_CA7_STANDBYWFE0 HDP7_CA7_DBGACK0 HDP7_BSEC_OUT_FUSE_OK HDP7_BSEC_OUT_SEC_SPIDEN HDP7_ETH_OUT_MAC_SPEED_O0 HDP7_GPU_DBG0 HDP7_DDRCTRL_CSYSREQ_DDRC HDP7_DDRCTRL_HPR_CREDIT_CNT HDP7_GPOVAL_7
4. How to configure the DT using STM32CubeMX[edit source]
The STM32CubeMX tool can be used to configure the STM32MPU device and get the corresponding platform configuration device tree files.
The STM32CubeMX may not support all the properties described in the above DT bindings documentation paragraph. If so, the tool inserts user sections in the generated device tree. These sections can then be edited to add some properties and they are preserved from one generation to another. Refer to STM32CubeMX user manual for further information.
5. References[edit source]
- ↑ <Linux kernel directory>/Documentation/devicetree/bindings/soc/stm32/stm32_hdp.txt
- ↑ arch/arm/boot/dts/stm32mp157c.dtsi , STM32MP157C device tree file