Commit fa0f8d67 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Sebastian Reichel
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power: reset: Add reset driver for R-Mobile platforms 



Add a reset driver for Renesas R-Mobile and SH-Mobile SoCs. It registers
a restart handler to trigger a soft power-on reset through the R-Mobile
System Controller.
The priority of this restart handler is 192, to allow a watchdog driver
to use priority 128.

Note that we do not use syscon-reboot, as the HPB (Peripheral Bus
Bridge) semaphore should be acquired on systems where both the ARM and
SH core are in use. The driver can be extended later to support this,
when needed.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSebastian Reichel <sre@kernel.org>
parent 85cdf36e

drivers/power/reset/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -159,5 +159,11 @@ config POWER_RESET_SYSCON 
	help

	  Reboot support for generic SYSCON mapped register reset.



config POWER_RESET_RMOBILE

	tristate "Renesas R-Mobile reset driver"

	depends on ARCH_RMOBILE || COMPILE_TEST

	help

	  Reboot support for Renesas R-Mobile and SH-Mobile SoCs.



endif

drivers/power/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -18,3 +18,4 @@ obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o 
obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o

obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o

obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o

obj-$(CONFIG_POWER_RESET_RMOBILE) += rmobile-reset.o

drivers/power/reset/rmobile-reset.c

0 → 100644
+91 −0
Original line number Diff line number Diff line 
/*

 * Renesas R-Mobile Reset Driver

 *

 * Copyright (C) 2014 Glider bvba

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 */



#include <linux/io.h>

#include <linux/module.h>

#include <linux/notifier.h>

#include <linux/of_address.h>

#include <linux/platform_device.h>

#include <linux/printk.h>

#include <linux/reboot.h>



/* SYSC Register Bank 2 */

#define RESCNT2		0x20		/* Reset Control Register 2 */



/* Reset Control Register 2 */

#define RESCNT2_PRES	0x80000000	/* Soft power-on reset */



static void __iomem *sysc_base2;



static int rmobile_reset_handler(struct notifier_block *this,

				 unsigned long mode, void *cmd)

{

	pr_debug("%s %lu\n", __func__, mode);



	/* Let's assume we have acquired the HPB semaphore */

	writel(RESCNT2_PRES, sysc_base2 + RESCNT2);



	return NOTIFY_DONE;

}



static struct notifier_block rmobile_reset_nb = {

	.notifier_call = rmobile_reset_handler,

	.priority = 192,

};



static int rmobile_reset_probe(struct platform_device *pdev)

{

	int error;



	sysc_base2 = of_iomap(pdev->dev.of_node, 1);

	if (!sysc_base2)

		return -ENODEV;



	error = register_restart_handler(&rmobile_reset_nb);

	if (error) {

		dev_err(&pdev->dev,

			"cannot register restart handler (err=%d)\n", error);

		goto fail_unmap;

	}



	return 0;



fail_unmap:

	iounmap(sysc_base2);

	return error;

}



static int rmobile_reset_remove(struct platform_device *pdev)

{

	unregister_restart_handler(&rmobile_reset_nb);

	iounmap(sysc_base2);

	return 0;

}



static const struct of_device_id rmobile_reset_of_match[] = {

	{ .compatible = "renesas,sysc-rmobile", },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, rmobile_reset_of_match);



static struct platform_driver rmobile_reset_driver = {

	.probe = rmobile_reset_probe,

	.remove = rmobile_reset_remove,

	.driver = {

		.name = "rmobile_reset",

		.of_match_table = rmobile_reset_of_match,

	},

};



module_platform_driver(rmobile_reset_driver);



MODULE_DESCRIPTION("Renesas R-Mobile Reset Driver");

MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");

MODULE_LICENSE("GPL v2");

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