[RFC PATCH 2/3] mfd: rk8xx: release the power hold GPIOs before powering off
From: Yaozhong Li <hidden>
Date: 2026-09-09 09:28:24
Also in:
linux-devicetree, linux-rockchip, lkml
Subsystem:
multifunction devices (mfd), the rest · Maintainers:
Lee Jones, Linus Torvalds
rk808_power_off() writes the PMIC's shutdown bit directly. On boards with "power hold" lines driven by the SoC, a shutdown performed this way does not stick: the rails drop and immediately come back up, so the board restarts instead of staying off. U-Boot reports the result as a power-on reset. Take those lines as an optional GPIO array, hold them asserted while the system runs and release them - waiting power-hold-delay-ms - before writing the shutdown bit. Device trees without the property retain the existing behaviour. Releasing every described line matters: on a Firefly-RK3399 the board stays off when both lines described for it are released, whereas releasing GPIO1_D0 while GPIO1_B5 is left asserted makes it come back up. Signed-off-by: Yaozhong Li <redacted> --- drivers/mfd/rk8xx-core.c | 29 +++++++++++++++++++++++++++++ include/linux/mfd/rk808.h | 4 ++++ 2 files changed, 33 insertions(+)
diff --git a/drivers/mfd/rk8xx-core.c b/drivers/mfd/rk8xx-core.c
index 3dcf6ab..fd1efbb 100644
--- a/drivers/mfd/rk8xx-core.c
+++ b/drivers/mfd/rk8xx-core.c@@ -11,6 +11,8 @@ */ #include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> #include <linux/interrupt.h> #include <linux/mfd/rk808.h> #include <linux/mfd/core.h>
@@ -703,6 +705,24 @@ static int rk808_power_off(struct sys_off_data *data) default: return NOTIFY_DONE; } + + /* + * Some boards route "power hold" lines from the SoC into the board's + * power circuitry. They have to be held asserted while the system is + * running and released before the PMIC shutdown request is written: + * with any of them left asserted, the rails drop and then come back + * up. Releasing them here rather than from a separate handler keeps + * the ordering against the I2C write explicit. + */ + if (rk808->power_hold_gpios) { + unsigned int i; + + for (i = 0; i < rk808->power_hold_gpios->ndescs; i++) + gpiod_set_value_cansleep(rk808->power_hold_gpios->desc[i], 0); + + msleep(rk808->power_hold_delay_ms); + } + ret = regmap_update_bits(rk808->regmap, reg, bit, bit); if (ret) dev_err(rk808->dev, "Failed to shutdown device!\n");
@@ -874,6 +894,15 @@ int rk8xx_probe(struct device *dev, int variant, unsigned int irq, struct regmap if (device_property_read_bool(dev, "system-power-controller") || device_property_read_bool(dev, "rockchip,system-power-controller")) { + rk808->power_hold_gpios = devm_gpiod_get_array_optional(dev, + "power-hold", GPIOD_OUT_HIGH); + if (IS_ERR(rk808->power_hold_gpios)) + return dev_err_probe(dev, PTR_ERR(rk808->power_hold_gpios), + "failed to get power hold GPIOs\n"); + + device_property_read_u32(dev, "power-hold-delay-ms", + &rk808->power_hold_delay_ms); + ret = devm_register_sys_off_handler(dev, SYS_OFF_MODE_POWER_OFF_PREPARE, SYS_OFF_PRIO_HIGH, &rk808_power_off, rk808);
diff --git a/include/linux/mfd/rk808.h b/include/linux/mfd/rk808.h
index 7ffc904..eda111e 100644
--- a/include/linux/mfd/rk808.h
+++ b/include/linux/mfd/rk808.h@@ -1459,6 +1459,8 @@ enum { RK818_ID = 0x8180, }; +struct gpio_descs; + struct rk808 { struct device *dev; struct regmap_irq_chip_data *irq_data;
@@ -1466,6 +1468,8 @@ struct rk808 { long variant; const struct regmap_config *regmap_cfg; const struct regmap_irq_chip *regmap_irq_chip; + struct gpio_descs *power_hold_gpios; + u32 power_hold_delay_ms; }; void rk8xx_shutdown(struct device *dev);
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2.55.0.windows.3