Rockchip RK805 PMIC Developer Guide: Power, DTS and Debugging

Source RK-KF-YF-127 V1.1.1, RK805, Linux 3.10 / 4.4 / 4.19. Covers PMIC submodules, concepts, functions, DTS and issue diagnosis. Platform reference only: verify the ArmSoM board PMIC, SoC, SDK/BSP, kernel, supplies and wiring. No ArmSoM hardware validation. Only a Chinese source is available; all four languages use its original figures, including any embedded English labels. No corresponding English PDF exists in this batch. Hardware commands are documented, not executed.

ArmSoM Docs · Rockchip Linux

1. Basics

1.1 Overview

RK805 is a high-performance PMIC integrating 4 high-current DCDCs, 3 LDOs, 1 RTC and adjustable power-on sequencing. System supplies are generally DCDC or LDO; their characteristics follow (consult detailed references separately).

1. DCDC: high efficiency at large input/output voltage differences, but high ripple and cost; suitable for large voltage differences and high-current loads. PWM has good ripple transient response but lower efficiency; PFM is efficient but has limited load capability.

1. LDO: low efficiency at large voltage differences and low cost. For example, a 1.1V LDO output can be supplied from the VCCIO_3.3V DCDC to improve efficiency. Where the circuit permits, feed the LDO from a DCDC output, taking power-on sequencing into account.

1.2 Functions

RK805 functions can be grouped into four parts:

1. Regulator: control each DCDC/LDO power state.

1. RTC: clock timekeeping and timers.

1. GPIO: out1 and out2 are push-pull output pins, usable as ordinary GPIOs but output-only.

1. Pwrkey: detect power-button press/release, saving an AP GPIO.

1.3 Chip pin functions

Original figure from Chinese PDF — p.5

Pay particular attention to SLEEP and INT in the following description.

Original figure from Chinese PDF — p.5

Original figure from Chinese PDF — p.6

Pin definitions (transcribed row by row from the figures above; source names and I/O markers retained)

1.4 Important concepts

I2C 7-bit slave address: 0x18. PMIC has three operating modes.

1. Normal mode: during normal system operation PMIC is in normal mode and pmic_sleep is low.

1. Sleep mode: to minimize standby power, PMIC reduces its own consumption, lowers selected output voltages or turns outputs off according to product needs. AP configures pmic_sleep for sleep via I2C, then raises it to enter sleep. On SoC wake-up it returns low and PMIC exits sleep.

1. Shutdown mode: AP configures pmic_sleep for shutdown via I2C and raises it to power down the entire system.

• pmic_sleep: low means normal operation; high selects sleep or shutdown.
• pmic_int: normally high, low on interrupt and remains low until handled.
• out1/out2: push-pull general GPIO outputs only.
• pmic_pwron: connect the power button; the driver detects press/release.
• DCDC supports PWM (force PWM), PFM, and AUTO switching between them. AUTO is efficient but has poorer ripple transient response. For stability, runtime uses PWM and sleep uses AUTO PWM/PFM.
• DCDC3 voltage adjustment:

DCDC3 voltage cannot be changed through registers, only through external divider resistors. Change the peripheral hardware if necessary; Rockchip typically uses it for VCC_DDR. Runtime DCDC/LDO adjustment ranges follow.

1. DCDC voltage range is discontinuous:

1. LDO voltage range is continuous:

1.5 Power-on conditions and sequence

1. Power-on: any condition suffices: EN changes from low to high; EN stays high and RTC alarm interrupt occurs; EN stays high and PWRON is pressed.

1. Different SoC platforms may require different supply sequences. See the latest datasheet for the following available sequences.

Original figure from Chinese PDF — p.7

Editable transcription of source Table 4-1: RK805-0 AP=Null, BOOT(OTP)=0; RK805-1 AP=RK3228, BOOT(OTP)=1; RK805-2 AP=RK1108, BOOT(OTP)=1.

2. Configuration

2.1 Driver and menuconfig

Kernel 3.10 configuration. RK805 reuses the RK816 driver:

drivers/mfd/rk816.c
drivers/input/misc/rk816-pwrkey.c
drivers/rtc/rtc-rk816.c
drivers/gpio/gpio-rk816.c
drivers/regulator/rk816-regulator.c

Corresponding menuconfig options:

CONFIG_MFD_RK816
CONFIG_GPIO_RK816
CONFIG_RTC_RK816
CONFIG_REGULATOR_RK816
CONFIG_INPUT_RK816_PWRKEY

Kernel 4.4 configuration. RK805 driver files:

drivers/mfd/rk808.c
drivers/input/misc/rk8xx-pwrkey.c
drivers/rtc/rtc-rk808.c
drivers/gpio/gpio-rk8xx.c
drivers/regulator/rk818-regulator.c
drivers/clk/clk-rk808.c

Corresponding menuconfig options:

CONFIG_MFD_RK808
CONFIG_RTC_RK808
CONFIG_GPIO_RK8XX
CONFIG_REGULATOR_RK818
CONFIG_INPUT_RK8XX_PWRKEY
CONFIG_COMMON_CLK_RK808

Kernel 4.19 configuration. RK805 driver files:

drivers/mfd/rk808.c
drivers/input/misc/rk805-pwrkey.c       // 跟4.4内核不同
drivers/rtc/rtc-rk808.c
drivers/pinctrl/pinctrl-rk805.c         // 跟4.4内核不同
drivers/regulator/rk808-regulator.c     // 跟4.4内核不同
drivers/clk/clk-rk808.c

Corresponding menuconfig options:

CONFIG_MFD_RK808
CONFIG_RTC_RK808
CONFIG_PINCTRL_RK805
CONFIG_REGULATOR_RK808
CONFIG_INPUT_RK805_PWRKEY
CONFIG_COMMON_CLK_RK808

2.2 DTS configuration

Kernel 3.10 DTS includes I2C attachment, main node, regulator, rtc and poweroff.

&i2c1 {
    rk805: rk805@18 {
        reg = <0x18>;
        status = "okay";
    };
};

#include "../../../arm/boot/dts/rk805.dtsi"
&rk805 {
    gpios = <&gpio2 GPIO_A6 GPIO_ACTIVE_HIGH>, <&gpio2 GPIO_D2 GPIO_ACTIVE_LOW>;
    rk805,system-power-controller;
    gpio-controller;
    #gpio-cells = <2>;

    rtc {
        status = "disabled";
    };

    regulators {
        rk805_dcdc1_reg: regulator@0 {
            regulator-name = "vdd_logic";
            regulator-min-microvolt = <700000>;
            regulator-max-microvolt = <1500000>;
            regulator-initial-mode = <0x1>;
            regulator-initial-state = <3>;
            regulator-boot-on;
            regulator-always-on;
            regulator-state-mem {
                regulator-state-mode = <0x2>;
                regulator-state-enabled;
                regulator-state-uv = <1000000>;
            };
        };
        rk805_dcdc2_reg: regulator@1 {
                    .............
        };
        rk805_dcdc3_reg: regulator@2 {
                    .............
        };
        .................................
    };
};

1. Attach the complete rk805 node below its I2C node and set status = “okay”.

1. Main node: the following must not be modified.

rk805,system-power-controller：声明RK805具备管理系统下电的功能；
gpio-controller：声明RK805具有GPIO的功能；
#gpio-cells：使⽤者引⽤RK805的GPIO时需要指定的参数个数;

To reference an RK805 GPIO use gpios = <&rk805 0 GPIO_ACTIVE_LOW>;. Parameter 1 is fixed &rk805; parameter 2 is 0 (out1) or 1 (out2); parameter 3 is polarity. Editable gpios in the main node specifies pmic_int first and pmic_sleep second.

1. Regulator properties:

• regulator-name: supply name, preferably matching the schematic; matched by regulator_get.
• regulator-min-microvolt / regulator-max-microvolt: minimum/maximum runtime voltage.
• regulator-initial-mode: runtime DCDC mode, usually 1; 1 force pwm, 2 auto pwm/pfm.
• regulator-state-mode: sleep DCDC mode, usually 2; same values.
• regulator-initial-state: suspend mode, must be 3.
• regulator-boot-on: enable at registration.
• regulator-always-on: forbid runtime shutdown and enable at registration.
• regulator-state-enabled: keep powered in sleep; replace with regulator-state-disabled to turn off.
• regulator-state-uv: standby voltage when sleep does not cut power.

When regulator-min-microvolt and regulator-max-microvolt are equal, registration automatically sets that voltage and enables the supply. regulator-boot-on or regulator-always-on also causes automatic enabling: equal limits set the specified voltage; unequal limits retain the PMIC hardware default power-on voltage.

1. RTC: to disable RTC, for example in a box product, add its node and explicitly set status = “disabled”. To enable it, remove the entire RTC node or set status = “okay”.

1. Poweroff

gpio_poweroff {
    compatible = "gpio-poweroff";
    gpios = <&gpio2 GPIO_D2 GPIO_ACTIVE_HIGH>;
    status = "okay";
};

RK805 powers down the entire PMIC by raising pmic_sleep. Add this node under the root; gpios is editable and identifies pmic_sleep.

Kernel 4.4 DTS includes I2C attachment, main node, rtc, pwrkey, gpio and regulator.

&pinctrl {
    pmic {
        pmic_int_l: pmic-int-l {
        rockchip,pins =
            <2 6 RK_FUNC_GPIO &pcfg_pull_up>;   /* gpio2_a6 */
        };
    };
};

&i2c1 {
    status = "okay";
    rk805: rk805@18 {
        compatible = "rockchip,rk805";
        status = "okay";
        reg = <0x18>;
        interrupt-parent = <&gpio2>;
        interrupts = <6 IRQ_TYPE_LEVEL_LOW>;
        pinctrl-names = "default";
        pinctrl-0 = <&pmic_int_l>;
        rockchip,system-power-controller;
        wakeup-source;
        gpio-controller;
        #gpio-cells = <2>;
        rtc {
            status = "disabled";
        };
        pwrkey {
            status = "disabled";
        };
        gpio {
            status = "okay";
        };
        regulators {
            compatible = "rk805-regulator";
            status = "okay";
            #address-cells = <1>;
            #size-cells = <0>;
            vdd_logic: RK805_DCDC1@0 {
                regulator-compatible = "RK805_DCDC1";
                regulator-name = "vdd_logic";
                regulator-init-microvolt = <1100000>;
                regulator-min-microvolt = <712500>;
                regulator-max-microvolt = <1450000>;
                regulator-initial-mode = <0x1>;
                regulator-ramp-delay = <12500>;
                regulator-boot-on;
                regulator-always-on;
                regulator-state-mem {
                    regulator-mode = <0x2>;
                    regulator-on-in-suspend;
                    regulator-suspend-microvolt = <1000000>;
                };
            };

            vdd_arm: RK805_DCDC2@1 {
                .................
            };
            vcc_ddr: RK805_DCDC3@2 {
                .................
            };
            .............................
        };
    };
};

1. Attach the complete rk805 node below its I2C node and set status = “okay”.

1. Main node: the following must not be modified.

compatible = "rockchip,rk805";
reg = <0x18>;
rockchip,system-power-controller;
wakeup-source;
gpio-controller;
#gpio-cells = <2>;

Editable fields follow the pinctrl rules:

interrupt-parent: GPIO controller owning pmic_int; interrupts: pin index and polarity within that controller; pinctrl-names: fixed “default”; pinctrl-0: reference to pmic_int defined in pinctrl.

1. rtc, pwrkey, gpio: if selected in menuconfig but not needed, add the corresponding DTS nodes with status = “disabled”. Drivers remain disabled; boot error logs may appear and can be ignored. To enable, remove the corresponding node or use status = “okay”.

1. Regulator:

• regulator-compatible: registration match name; cannot change, or loading fails.
• regulator-name: supply name, preferably matching hardware; regulator_get uses it.
• regulator-init-microvolt: u-boot initial voltage, ineffective in kernel.
• regulator-min-microvolt / regulator-max-microvolt: runtime minimum/maximum.
• regulator-initial-mode: runtime DCDC mode, usually 1; 1 force pwm, 2 auto pwm/pfm.
• regulator-mode: sleep DCDC mode, usually 2; same values.
• regulator-initial-state: suspend mode, must be 3.
• regulator-boot-on: enable at registration.
• regulator-always-on: forbid runtime shutdown and enable at registration.
• regulator-ramp-delay: DCDC voltage rise time, fixed 12500.
• regulator-on-in-suspend: keep power during sleep; replace with regulator-off-in-suspend to turn off.
• regulator-suspend-microvolt: standby voltage if power stays on.

Kernel 4.19: follow the 4.4 DTS. Difference: the gpio child node is no longer required, but other modules still reference RK805 pins with gpios = <&rk805 0 GPIO_ACTIVE_LOW>;.

2.3 Function interfaces

The following interfaces cover ordinary regulator on/off, voltage setting and reading.

1. Get regulator: struct regulator *regulator_get(struct device *dev, const char *id). dev may be NULL; id matches regulator-name in DTS.

1. Release: void regulator_put(struct regulator *regulator)

1. Enable: int regulator_enable(struct regulator *regulator)

1. Disable: int regulator_disable(struct regulator *regulator)

1. Read voltage: int regulator_get_voltage(struct regulator *regulator)

1. Set voltage: int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV). Caller must ensure min_uV = max_uV.

1. Example

struct regulator *rdev_logic;

rdev_logic = regulator_get(NULL, "vdd_logic");          // 获取vdd_logic
regulator_enable(rdev_logic);                           // 使能vdd_logic
regulator_set_voltage(rdev_logic, 1100000, 1100000);    // 设置电压1.1v
regulator_disable(rdev_logic);                          // 关闭vdd_logic
regulator_put(rdev_logic);                              // 释放vdd_logic

Kernels 4.4 and 4.19 also provide devm_ regulator interfaces for managing allocated resources.

3. Debugging

3.1 Kernel 3.10

PMIC driver usage logic is simple; final register configuration is crucial. Inspect RK805 registers through /sys/rk816/rk816_test. Read: echo r [addr] > /sys/rk816/rk816_test. Write: echo w [addr] [value] > /sys/rk816/rk816_test. Example: echo r 0x2f > /sys/rk816/rk816_test reads register 0x2f, shown as 0x9b.

Transcription of legible source-image content (source example; unreadable clipped edge fragments are not guessed):

1|shell@rk3228h:/ # echo r 0x2f > /sys/rk816/rk816_test
[  283.091704]  [2:             sh:  618] ------zhangqing: get cmd = r
[  283.091766]  [2:             sh:  618] CMD : r 2f
[  283.091914]  [2:             sh:  618]
[  283.091914]  [2:             sh:  618] 2f 9b

Original figure from Chinese PDF — p.14

echo w 0x2f 0x9c > /sys/rk816/rk816_test sets register 0x2f to 0x9c.

Read back after writing to confirm success.

Transcription of legible source-image content (source example; unreadable clipped edge fragments are not guessed):

1|shell@rk3228h:/ # echo r 0x2f > /sys/rk816/rk816_test
[  283.091704]  [2:             sh:  618] ------zhangqing: get cmd = r
[  283.091766]  [2:             sh:  618] CMD : r 2f
[  283.091914]  [2:             sh:  618]
[  283.091914]  [2:             sh:  618] 2f 9b

Original figure from Chinese PDF — p.15

3.2 Kernel 4.4

Command syntax matches kernel 3.10, but kernel 4.4 uses /sys/rk8xx/rk8xx_dbg.

3.3 Kernel 4.19

Refer to the kernel 4.4 commands.

Editorial note: the source voltage table contains 0.737.5, an apparent typo retained without guessing a correction. Register screenshots are source examples, not ArmSoM measurements.