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authorMichael Klein <michael@fossekall.de>2020-12-11 18:14:43 +0300
committerSebastian Reichel <sebastian.reichel@collabora.com>2020-12-13 02:14:15 +0300
commitec66096b7696d40c8d321d2b1c6cdb856a9767be (patch)
tree1027ae5f88e931f2e44ce6c00ec8d898ae3f9982 /drivers/power/reset
parent36f1de0d5c463092485c73ab639c348d1e28e356 (diff)
downloadlinux-ec66096b7696d40c8d321d2b1c6cdb856a9767be.tar.xz
power: reset: new driver regulator-poweroff
This driver registers a pm_power_off function to turn off the board by force-disabling a devicetree-defined regulator. Signed-off-by: Michael Klein <michael@fossekall.de> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers/power/reset')
-rw-r--r--drivers/power/reset/Kconfig7
-rw-r--r--drivers/power/reset/Makefile1
-rw-r--r--drivers/power/reset/regulator-poweroff.c82
3 files changed, 90 insertions, 0 deletions
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index d55b3727e00e..b22c4fdb2561 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
+ power regulator 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..f697088e0ad1
--- /dev/null
+++ b/drivers/power/reset/regulator-poweroff.c
@@ -0,0 +1,82 @@
+// 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/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#define 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 *cpu_regulator;
+
+static void regulator_poweroff_do_poweroff(void)
+{
+ if (cpu_regulator && regulator_is_enabled(cpu_regulator))
+ regulator_force_disable(cpu_regulator);
+
+ /* give it some time */
+ mdelay(TIMEOUT_MS);
+
+ WARN_ON(1);
+}
+
+static int regulator_poweroff_probe(struct platform_device *pdev)
+{
+ /* 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;
+ }
+
+ cpu_regulator = devm_regulator_get(&pdev->dev, "cpu");
+ if (IS_ERR(cpu_regulator))
+ return PTR_ERR(cpu_regulator);
+
+ pm_power_off = &regulator_poweroff_do_poweroff;
+ return 0;
+}
+
+static int regulator_poweroff_remove(__maybe_unused struct platform_device *pdev)
+{
+ if (pm_power_off == &regulator_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);
+
+MODULE_AUTHOR("Michael Klein <michael@fossekall.de>");
+MODULE_DESCRIPTION("Regulator poweroff driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:poweroff-regulator");