PMIC
Introduction to the Functions and Usage Methods of PMIC. Currently, our company supports the P1 PMIC chip, which has corresponding control interfaces in the SPL/UBOOT/KERNEL stages.
Usage Methods in SPL/UBOOT
uboot - 2022.10$ vi arch/riscv/dts/k1 - x_spm8821.dtsi
&i2c8 {
clock - frequency = <100000>;
u - boot, dm - spl;
status = "okay";
spm8821: pmic@41 {
compatible = "spacemit, spm8821";
reg = <0x41>;
bus = <8>;
u - boot, dm - spl;
regulators {
/* buck */
dcdc_6: DCDC_REG1 {
regulator - name = "dcdc1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - init - microvolt = <950000>;
regulator - boot - on;
u - boot, dm - spl;
regulator - state - mem {
regulator - off - in - suspend;
};
};
dcdc_7: DCDC_REG2 {
regulator - name = "dcdc2";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
};
dcdc_8: DCDC_REG3 {
regulator - name = "dcdc3";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - boot - on;
u - boot, dm - spl;
};
dcdc_9: DCDC_REG4 {
regulator - name = "dcdc4";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
};
dcdc_10: DCDC_REG5 {
regulator - name = "dcdc5";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
};
dcdc_11: DCDC_REG6 {
regulator - name = "dcdc6";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
};
/* aldo */
ldo_23: LDO_REG1 {
regulator - name = "ldo1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
regulator - init - microvolt = <3300000>;
regulator - boot - on;
u - boot, dm - spl;
};
ldo_24: LDO_REG2 {
regulator - name = "ldo2";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_25: LDO_REG3 {
regulator - name = "ldo3";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_26: LDO_REG4 {
regulator - name = "ldo4";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
/* dldo */
ldo_27: LDO_REG5 {
regulator - name = "ldo5";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_28: LDO_REG6 {
regulator - name = "ldo6";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_29: LDO_REG7 {
regulator - name = "ldo7";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_30: LDO_REG8 {
regulator - name = "ldo8";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_31: LDO_REG9 {
regulator - name = "ldo9";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_32: LDO_REG10 {
regulator - name = "ldo10";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_33: LDO_REG11 {
regulator - name = "ldo11";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
sw_2: SWITCH_REG1 {
regulator - name = "switch1";
};
};
};
};
Power On and Voltage Setting Methods in the SPL Stage
dcdc_6: DCDC_REG1 {
regulator - name = "dcdc1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - init - microvolt = <950000>; ---> Adding this field will automatically set the power supply voltage to 0.95v
regulator - boot - on; ---> Adding this field will automatically turn on this power supply in the SPL stage
u - boot, dm - spl; ---> This field needs to be added for the SPL to recognize this dts node
regulator - state - mem {
regulator - off - in - suspend;
};
};
Power On and Voltage Setting Methods in the UBOOT Stage
There are two ways to set or turn on the power supply in the uboot stage. The first is to configure it directly in the dts.
dcdc_6: DCDC_REG1 { --> The name parameter passed to regulator_get_by_devname
regulator - name = "dcdc1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - init - microvolt = <950000>; ---> Adding this field will automatically set the power supply voltage to 0.95v
regulator - boot - on; ---> Adding this field will automatically turn on this power supply in the UBOOT stage
regulator - state - mem {
regulator - off - in - suspend;
};
};
The other is to set it directly in the code:
1. First, obtain the regulator handle for the voltage you want to set or turn on.
struct udevice *rdev = NULL;
char *regulator_name = "DCDC_REG1" --> This field is the name of the dts node identified in the dts.
ret = regulator_get_by_devname(regulator_name, &rdev);
2. Turn on a certain power supply.
regulator_set_enable(&rdev, true);
3. Set the voltage of a certain power supply.
regulator_set_value(&rdev, 1800000);
Usage Methods in the Linux Kernel
The relevant dts configurations in the Linux kernel are:
&i2c8 {
pinctrl - names = "default";
pinctrl - 0 = <&pinctrl_i2c8>;
status = "okay";
spm8821@41 {
compatible = "spacemit, spm8821";
reg = <0x41>;
interrupt - parent = <&intc>;
interrupts = <64>;
status = "okay";
vcc_sys - supply = <&vcc4v0_baseboard>;
dcdc5 - supply = <&dcdc_5>;
regulators {
compatible = "pmic, regulator, spm8821";
/* buck */
dcdc_1: DCDC_REG1 {
regulator - name = "dcdc1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - always - on;
};
dcdc_2: DCDC_REG2 {
regulator - name = "dcdc2";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - always - on;
};
dcdc_3: DCDC_REG3 {
regulator - name = "dcdc3";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <1800000>;
regulator - always - on;
};
dcdc_4: DCDC_REG4 {
regulator - name = "dcdc4";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3300000>;
regulator - always - on;
};
dcdc_5: DCDC_REG5 {
regulator - name = "dcdc5";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - always - on;
};
dcdc_6: DCDC_REG6 {
regulator - name = "dcdc6";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3450000>;
regulator - always - on;
};
/* aldo */
ldo_1: LDO_REG1 {
regulator - name = "ldo1";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
regulator - boot - on;
};
ldo_2: LDO_REG2 {
regulator - name = "ldo2";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_3: LDO_REG3 {
regulator - name = "ldo3";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_4: LDO_REG4 {
regulator - name = "ldo4";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
/* dldo */
ldo_5: LDO_REG5 {
regulator - name = "ldo5";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
regulator - boot - on;
};
ldo_6: LDO_REG6 {
regulator - name = "ldo6";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_7: LDO_REG7 {
regulator - name = "ldo7";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_8: LDO_REG8 {
regulator - name = "ldo8";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
regulator - always - on;
};
ldo_9: LDO_REG9 {
regulator - name = "ldo9";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
ldo_10: LDO_REG10 {
regulator - name = "ldo10";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
regulator - always - on;
};
ldo_11: LDO_REG11 {
regulator - name = "ldo11";
regulator - min - microvolt = <500000>;
regulator - max - microvolt = <3400000>;
};
sw_1: SWITCH_REG1 {
regulator - name = "switch1";
};
};
pmic_pinctrl: pinctrl {
compatible = "pmic, pinctrl, spm8821";
gpio - controller;
#gpio - cells = <2>;
spacemit, npins = <6>;
/**
* led_pins: led - pins {
* pins = "PIN3";
* function = "sleep";
* bias - disable = <0>;
* drive - open - drain = <0x1>;
* };
*/
};
pwr_key: key {
compatible = "pmic, pwrkey, spm8821";
};
ext_rtc: rtc {
compatible = "pmic, rtc, spm8821";
};
};
};
The method of using the regulator in the Linux kernel driver:
1. Configure the dts and reference the regulator you want to use.
&cpu_0 {
clst0 - supply = <&dcdc_1>;
vin - supply - names = "clst0";
};
Obtain the corresponding handle in the code:
const char *strings;
struct regulator *regulator;
err = of_property_read_string_array(cpu_dev -> of_node, "vin - supply - names",
&strings, 1);
regulator = devm_regulator_get(cpu_dev, strings); --> The struct device * passed in must have a corresponding entity.
Enable the corresponding regulator in the code:
regulator_enable(regulator);
Set the voltage of the corresponding regulator in the code:
regulator_set_voltage(regulator, 95000000, 95000000);