@@ -227,5 +227,14 @@ config SYSCON_REBOOT_MODE
register, then the bootloader can read it to take different
action according to the mode.
+config POWER_RESET_SC27XX
+ tristate "Spreadtrum SC27xx PMIC power-off driver"
+ depends on MFD_SC27XX_PMIC || COMPILE_TEST
+ help
+ This driver supports powering off a system through
+ Spreadtrum SC27xx series PMICs. The SC27xx series
+ PMICs includes the SC2720, SC2721, SC2723, SC2730
+ and SC2731 chips.
+
endif
@@ -27,3 +27,4 @@ obj-$(CONFIG_POWER_RESET_RMOBILE) += rmobile-reset.o
obj-$(CONFIG_POWER_RESET_ZX) += zx-reboot.o
obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
+obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
new file mode 100644
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Spreadtrum Communications Inc.
+ * Copyright (C) 2018 Linaro Ltd.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/syscore_ops.h>
+
+#define SC27XX_PWR_PD_HW 0xc2c
+#define SC27XX_PWR_OFF_EN BIT(0)
+
+static struct regmap *regmap;
+
+/*
+ * On Spreadtrum platform, we need power off system through external SC27xx
+ * series PMICs, and it is one similar SPI bus mapped by regmap to access PMIC,
+ * which is not fast io access.
+ *
+ * So before stopping other cores, we need release other cores' resource by
+ * taking cpus down to avoid racing regmap or spi mutex lock when poweroff
+ * system through PMIC.
+ */
+void sc27xx_poweroff_shutdown(void)
+{
+ int cpu = smp_processor_id();
+
+ freeze_secondary_cpus(cpu);
+}
+
+static struct syscore_ops poweroff_syscore_ops = {
+ .shutdown = sc27xx_poweroff_shutdown,
+};
+
+static void sc27xx_poweroff_do_poweroff(void)
+{
+ regmap_write(regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN);
+}
+
+static int sc27xx_poweroff_probe(struct platform_device *pdev)
+{
+ if (regmap)
+ return -EINVAL;
+
+ regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!regmap)
+ return -ENODEV;
+
+ pm_power_off = sc27xx_poweroff_do_poweroff;
+ register_syscore_ops(&poweroff_syscore_ops);
+ return 0;
+}
+
+static int sc27xx_poweroff_remove(struct platform_device *pdev)
+{
+ if (pm_power_off == sc27xx_poweroff_do_poweroff)
+ pm_power_off = NULL;
+
+ regmap = NULL;
+ return 0;
+}
+
+static struct platform_driver sc27xx_poweroff_driver = {
+ .probe = sc27xx_poweroff_probe,
+ .remove = sc27xx_poweroff_remove,
+ .driver = {
+ .name = "sc27xx-poweroff",
+ },
+};
+module_platform_driver(sc27xx_poweroff_driver);
+
+MODULE_ALIAS("platform:sc27xx-poweroff");
+MODULE_DESCRIPTION("Spreadtrum SC27xx PMIC Poweroff Driver");
+MODULE_LICENSE("GPL v2");
On Spreadtrum platform, we need power off system through external SC27xx series PMICs including the SC2720, SC2721, SC2723, SC2730 and SC2731 chips. Thus this patch adds SC27xx series PMICs power-off support. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> --- Changes since v1: - Add remove interface. - Add regmap checking when probing the driver. - Add MODULE_ALIAS() --- drivers/power/reset/Kconfig | 9 ++++ drivers/power/reset/Makefile | 1 + drivers/power/reset/sc27xx-poweroff.c | 79 +++++++++++++++++++++++++++++++++ 3 files changed, 89 insertions(+) create mode 100644 drivers/power/reset/sc27xx-poweroff.c -- 1.7.9.5