Commit 9fa7cdb4 authored by Nikita Shubin's avatar Nikita Shubin Committed by Arnd Bergmann
Browse files

power: reset: Add a driver for the ep93xx reset 



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: default avatarNikita Shubin <nikita.shubin@maquefel.me>
Tested-by: default avatarAlexander Sverdlin <alexander.sverdlin@gmail.com>
Acked-by: default avatarSebastian Reichel <sre@kernel.org>
Acked-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 035f9007

drivers/power/reset/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -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

drivers/power/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/power/reset/ep93xx-restart.c

0 → 100644
+84 −0
Original line number Diff line number Diff line 
// 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);