[PATCH v9 05/38] power: reset: Add a driver for the ep93xx reset

Nikita Shubin via B4 Relay
2024-03-26T09:20:41Z

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 | 84 ++++++++++++++++++++++++++++++++++++
3 files changed, 95 insertions(+)

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fece990af4a7..389d5a193e5d 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -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
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index a95d1bd275d1..10782d32e1da 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -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
diff --git a/drivers/power/reset/ep93xx-restart.c b/drivers/power/reset/ep93xx-restart.c
new file mode 100644
index 000000000000..57cfb8620faf
--- /dev/null
+++ b/drivers/power/reset/ep93xx-restart.c
@@ -0,0 +1,84 @@
+// 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/container_of.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+
+#include <linux/soc/cirrus/ep93xx.h>
+
+#define EP93XX_SYSCON_DEVCFG 0x80
+#define EP93XX_SYSCON_DEVCFG_SWRST BIT(31)
+
+struct ep93xx_restart {
+ struct ep93xx_regmap_adev *aux_dev;
+ 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);
+ struct ep93xx_regmap_adev *aux = priv->aux_dev;
+
+ /* Issue the reboot */
+ aux->update_bits(aux->map, aux->lock, EP93XX_SYSCON_DEVCFG,
+ EP93XX_SYSCON_DEVCFG_SWRST, EP93XX_SYSCON_DEVCFG_SWRST);
+ aux->update_bits(aux->map, aux->lock, EP93XX_SYSCON_DEVCFG,
+ EP93XX_SYSCON_DEVCFG_SWRST, 0);
+
+ return NOTIFY_DONE;
+}
+
+static int ep93xx_reboot_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
+{
+ struct ep93xx_regmap_adev *rdev = to_ep93xx_regmap_adev(adev);
+ struct device *dev = &adev->dev;
+ struct ep93xx_restart *priv;
+ int err;
+
+ if (!rdev->update_bits)
+ return -ENODEV;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->aux_dev = rdev;
+
+ 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 auxiliary_device_id ep93xx_reboot_ids[] = {
+ {
+ .name = "soc_ep93xx.reset-ep93xx",
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(auxiliary, ep93xx_reboot_ids);
+
+static struct auxiliary_driver ep93xx_reboot_driver = {
+ .probe = ep93xx_reboot_probe,
+ .id_table = ep93xx_reboot_ids,
+};
+module_auxiliary_driver(ep93xx_reboot_driver);

--
2.41.0