From: Nikita Shubin <nikita.shubin@maquefel.me>
Implement the reset behaviour of the various EP93xx SoCS in drivers/power/reset.
It used to be located in arch/arm/mach-ep93xx.
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Acked-by: Sebastian Reichel <sre@kernel.org>
---
drivers/power/reset/Kconfig | 10 +++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/ep93xx-restart.c | 85 ++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+)
@@ -75,6 +75,16 @@ config POWER_RESET_BRCMSTB
Say Y here if you have a Broadcom STB board and you wish
to have restart support.
+config POWER_RESET_EP93XX
+ bool "Cirrus EP93XX reset driver" if COMPILE_TEST
+ depends on MFD_SYSCON
+ default ARCH_EP93XX
+ help
+ This driver provides restart support for Cirrus EP93XX SoC.
+
+ Say Y here if you have a Cirrus EP93XX SoC and you wish
+ to have restart support.
+
config POWER_RESET_GEMINI_POWEROFF
bool "Cortina Gemini power-off driver"
depends on ARCH_GEMINI || COMPILE_TEST
@@ -7,6 +7,7 @@ obj-$(CONFIG_POWER_RESET_ATC260X) += atc260x-poweroff.o
obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
obj-$(CONFIG_POWER_RESET_BRCMKONA) += brcm-kona-reset.o
obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
+obj-$(CONFIG_POWER_RESET_EP93XX) += ep93xx-restart.o
obj-$(CONFIG_POWER_RESET_GEMINI_POWEROFF) += gemini-poweroff.o
obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
new file mode 100644
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Cirrus EP93xx SoC reset driver
+ *
+ * Copyright (C) 2021 Nikita Shubin <nikita.shubin@maquefel.me>
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#include <linux/soc/cirrus/ep93xx.h>
+
+#define EP93XX_SYSCON_DEVCFG 0x80
+#define EP93XX_SYSCON_DEVCFG_SWRST BIT(31)
+
+struct ep93xx_restart {
+ struct regmap *map;
+ struct notifier_block restart_handler;
+};
+
+static int ep93xx_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct ep93xx_restart *priv =
+ container_of(this, struct ep93xx_restart, restart_handler);
+
+ /* Issue the reboot */
+ ep93xx_regmap_update_bits(priv->map, EP93XX_SYSCON_DEVCFG,
+ EP93XX_SYSCON_DEVCFG_SWRST, EP93XX_SYSCON_DEVCFG_SWRST);
+ ep93xx_regmap_update_bits(priv->map, EP93XX_SYSCON_DEVCFG,
+ EP93XX_SYSCON_DEVCFG_SWRST, 0);
+
+ return NOTIFY_DONE;
+}
+
+static int ep93xx_reboot_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ep93xx_restart *priv;
+ struct device_node *parent;
+ int err;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ parent = of_get_parent(dev->of_node);
+ if (!parent)
+ return dev_err_probe(dev, -EINVAL, "no syscon parent for reboot node\n");
+
+ priv->map = syscon_node_to_regmap(parent);
+ of_node_put(parent);
+ if (IS_ERR(priv->map))
+ return dev_err_probe(dev, -EINVAL, "no syscon regmap\n");
+
+ priv->restart_handler.notifier_call = ep93xx_restart_handle;
+ priv->restart_handler.priority = 128;
+
+ err = register_restart_handler(&priv->restart_handler);
+ if (err)
+ return dev_err_probe(dev, err, "can't register restart notifier\n");
+
+ return 0;
+}
+
+static const struct of_device_id ep93xx_reboot_of_match[] = {
+ {
+ .compatible = "cirrus,ep9301-reboot",
+ },
+ { /* sentinel */ }
+};
+
+static struct platform_driver ep93xx_reboot_driver = {
+ .probe = ep93xx_reboot_probe,
+ .driver = {
+ .name = "ep9301-reboot",
+ .of_match_table = ep93xx_reboot_of_match,
+ },
+};
+builtin_platform_driver(ep93xx_reboot_driver);