Messages in this thread | | | Date | Wed, 9 Dec 2020 21:34:00 +0100 | From | Michael Klein <> | Subject | Re: [PATCH v3 1/3] power: reset: new driver regulator-poweroff |
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On Tue, Dec 08, 2020 at 11:10:52AM +0100, Maxime Ripard wrote: >On Mon, Dec 07, 2020 at 03:27:54PM +0100, Michael Klein wrote: >> This driver registers a pm_power_off function to disable a set of >> regulators defined in the devicetree to turn off the board. >> >> Signed-off-by: Michael Klein <michael@fossekall.de> >> --- >> drivers/power/reset/Kconfig | 7 ++ >> drivers/power/reset/Makefile | 1 + >> drivers/power/reset/regulator-poweroff.c | 107 +++++++++++++++++++++++ >> 3 files changed, 115 insertions(+) >> create mode 100644 drivers/power/reset/regulator-poweroff.c >> >> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig >> index d55b3727e00e..ae6cb7b0bd4d 100644 >> --- a/drivers/power/reset/Kconfig >> +++ b/drivers/power/reset/Kconfig >> @@ -177,6 +177,13 @@ config POWER_RESET_QNAP >> >> Say Y if you have a QNAP NAS. >> >> +config POWER_RESET_REGULATOR >> + bool "Regulator subsystem power-off driver" >> + depends on OF && REGULATOR >> + help >> + This driver supports turning off your board by disabling a set >> + of regulators defined in the devicetree. >> + >> config POWER_RESET_RESTART >> bool "Restart power-off driver" >> help >> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile >> index c51eceba9ea3..9dc49d3a57ff 100644 >> --- a/drivers/power/reset/Makefile >> +++ b/drivers/power/reset/Makefile >> @@ -19,6 +19,7 @@ obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o >> obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o >> obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o >> obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o >> +obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o >> obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o >> obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o >> obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o >> diff --git a/drivers/power/reset/regulator-poweroff.c b/drivers/power/reset/regulator-poweroff.c >> new file mode 100644 >> index 000000000000..df2ca4fdcc49 >> --- /dev/null >> +++ b/drivers/power/reset/regulator-poweroff.c >> @@ -0,0 +1,107 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Force-disables a regulator to power down a device >> + * >> + * Michael Klein <michael@fossekall.de> >> + * >> + * Copyright (C) 2020 Michael Klein >> + * >> + * Based on the gpio-poweroff driver. >> + */ >> +#include <linux/delay.h> >> +#include <linux/init.h> >> +#include <linux/kernel.h> >> +#include <linux/module.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> +#include <linux/regulator/consumer.h> >> + >> +#define DEFAULT_TIMEOUT_MS 3000 >> + >> +/* >> + * Hold configuration here, cannot be more than one instance of the driver >> + * since pm_power_off itself is global. >> + */ >> +static struct regulator **poweroff_regulators; >> +static u32 timeout = DEFAULT_TIMEOUT_MS; >> + >> +static void regulator_poweroff_do_poweroff(void) >> +{ >> + struct regulator **it; >> + >> + if (poweroff_regulators) >> + for (it = poweroff_regulators; *it; ++it) >> + if (regulator_is_enabled(*it)) >> + regulator_force_disable(*it); >> + >> + /* give it some time */ >> + mdelay(timeout); >> + >> + WARN_ON(1); >> +} >> + >> +static int regulator_poweroff_probe(struct platform_device *pdev) >> +{ >> + int count; >> + const char *name; >> + struct regulator **it; >> + struct property *prop; >> + struct device_node *node = pdev->dev.of_node; >> + >> + /* If a pm_power_off function has already been added, leave it alone */ >> + if (pm_power_off != NULL) { >> + dev_err(&pdev->dev, >> + "%s: pm_power_off function already registered\n", >> + __func__); >> + return -EBUSY; >> + } >> + >> + count = of_property_count_strings(node, "regulator-names"); >> + if (count <= 0) >> + return -ENOENT; >> + >> + poweroff_regulators = devm_kcalloc(&pdev->dev, count + 1, >> + sizeof(struct regulator *), GFP_KERNEL); >> + >> + it = poweroff_regulators; >> + of_property_for_each_string(node, "regulator-names", prop, name) { >> + *it = devm_regulator_get(&pdev->dev, name); >> + if (IS_ERR(*it)) >> + return PTR_ERR(*it); >> + it++; >> + } >> + >> + of_property_read_u32(node, "timeout-ms", &timeout); >> + >> + pm_power_off = ®ulator_poweroff_do_poweroff; >> + return 0; >> +} >> + >> +static int regulator_poweroff_remove(__maybe_unused struct platform_device *pdev) >> +{ >> + if (pm_power_off == ®ulator_poweroff_do_poweroff) >> + pm_power_off = NULL; >> + >> + return 0; >> +} >> + >> +static const struct of_device_id of_regulator_poweroff_match[] = { >> + { .compatible = "regulator-poweroff", }, >> + {}, >> +}; >> + >> +static struct platform_driver regulator_poweroff_driver = { >> + .probe = regulator_poweroff_probe, >> + .remove = regulator_poweroff_remove, >> + .driver = { >> + .name = "poweroff-regulator", >> + .of_match_table = of_regulator_poweroff_match, >> + }, >> +}; >> + >> +module_platform_driver(regulator_poweroff_driver); > >Since this can't be compiled as a module, you can use >module_platform_driver_probe instead.
actually no, as platform_driver_probe() does not support deferred probing and the regulator might not be available during regulator_poweroff_probe() yet:
# dmesg | grep poweroff [ 0.788135] poweroff-regulator poweroff: probe deferral not supported
-- Michael
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