driver: reset: spacemit-p1: add driver for poweroff/reboot

This driver implements poweroff/reboot support for the SpacemiT P1 PMIC
chip, which is commonly paired with the SpacemiT K1 SoC.

The SpacemiT P1 support is implemented as a MFD driver, so the access is
done directly through the regmap interface. Reboot or poweroff is
triggered by setting a specific bit in a control register, which is
automatically cleared by the hardware afterwards.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Link: https://patch.msgid.link/20251102230352.914421-2-aurelien@aurel32.net
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 8248895ca90389c1db33c7b09e5f5925a9034cee..f6c1bcbb57deff3568d6b1b326454add3b3bbf06 100644 (file)
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -283,6 +283,15 @@ config POWER_RESET_KEYSTONE
        help
          Reboot support for the KEYSTONE SoCs.
 
+config POWER_RESET_SPACEMIT_P1
+       tristate "SpacemiT P1 poweroff and reset driver"
+       depends on ARCH_SPACEMIT || COMPILE_TEST
+       depends on MFD_SPACEMIT_P1
+       default MFD_SPACEMIT_P1
+       help
+         This driver supports power-off and reset operations for the SpacemiT
+         P1 PMIC.
+
 config POWER_RESET_SYSCON
        bool "Generic SYSCON regmap reset driver"
        depends on OF

diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 51da87e05ce76bc608d961485063555c3ba5d96c..0e4ae6f6b5c55729cf60846d47e6fe0fec24f3cc 100644 (file)
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -24,6 +24,7 @@ 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-$(CONFIG_POWER_RESET_SPACEMIT_P1) += spacemit-p1-reboot.o
 obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
 obj-$(CONFIG_POWER_RESET_TH1520_AON) += th1520-aon-reboot.o
 obj-$(CONFIG_POWER_RESET_TORADEX_EC) += tdx-ec-poweroff.o

diff --git a/drivers/power/reset/spacemit-p1-reboot.c b/drivers/power/reset/spacemit-p1-reboot.c
new file mode 100644 (file)
index 0000000..9ec3d1f
--- /dev/null
+++ b/drivers/power/reset/spacemit-p1-reboot.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 by Aurelien Jarno
+ */
+
+#include <linux/bits.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+
+/* Power Control Register 2 */
+#define PWR_CTRL2              0x7e
+#define PWR_CTRL2_SHUTDOWN     BIT(2)  /* Shutdown request */
+#define PWR_CTRL2_RST          BIT(1)  /* Reset request */
+
+static int spacemit_p1_pwroff_handler(struct sys_off_data *data)
+{
+       struct regmap *regmap = data->cb_data;
+       int ret;
+
+       /* Put the PMIC into shutdown state */
+       ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_SHUTDOWN);
+       if (ret) {
+               dev_err(data->dev, "shutdown failed: %d\n", ret);
+               return notifier_from_errno(ret);
+       }
+
+       return NOTIFY_DONE;
+}
+
+static int spacemit_p1_restart_handler(struct sys_off_data *data)
+{
+       struct regmap *regmap = data->cb_data;
+       int ret;
+
+       /* Put the PMIC into reset state */
+       ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_RST);
+       if (ret) {
+               dev_err(data->dev, "restart failed: %d\n", ret);
+               return notifier_from_errno(ret);
+       }
+
+       return NOTIFY_DONE;
+}
+
+static int spacemit_p1_reboot_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct regmap *regmap;
+       int ret;
+
+       regmap = dev_get_regmap(dev->parent, NULL);
+       if (!regmap)
+               return -ENODEV;
+
+       ret = devm_register_power_off_handler(dev, &spacemit_p1_pwroff_handler,
+                                             regmap);
+       if (ret)
+               return dev_err_probe(dev, ret,
+                                    "Failed to register power off handler\n");
+
+       ret = devm_register_restart_handler(dev, spacemit_p1_restart_handler,
+                                           regmap);
+       if (ret)
+               return dev_err_probe(dev, ret,
+                                    "Failed to register restart handler\n");
+
+       return 0;
+}
+
+static const struct platform_device_id spacemit_p1_reboot_id_table[] = {
+       { "spacemit-p1-reboot", },
+       { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, spacemit_p1_reboot_id_table);
+
+static struct platform_driver spacemit_p1_reboot_driver = {
+       .driver = {
+               .name = "spacemit-p1-reboot",
+       },
+       .probe = spacemit_p1_reboot_probe,
+       .id_table = spacemit_p1_reboot_id_table,
+};
+module_platform_driver(spacemit_p1_reboot_driver);
+
+MODULE_DESCRIPTION("SpacemiT P1 reboot/poweroff driver");
+MODULE_LICENSE("GPL");