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Commit ff591a91 authored by Alban Bedel's avatar Alban Bedel Committed by Philipp Zabel
Browse files

reset: Add a driver for the reset controller on the AR71XX/AR9XXX 



The AR71XX/AR9XXX SoC have a simple reset controller with one bit per
reset line.

Signed-off-by: default avatarAlban Bedel <albeu@free.fr>
Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent f25b5eda

arch/mips/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -118,6 +118,7 @@ config ATH25 


config ATH79

	bool "Atheros AR71XX/AR724X/AR913X based boards"

	select ARCH_HAS_RESET_CONTROLLER

	select ARCH_REQUIRE_GPIOLIB

	select BOOT_RAW

	select CEVT_R4K

drivers/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o 
obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o

obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o

obj-$(CONFIG_ARCH_STI) += sti/

obj-$(CONFIG_ATH79) += reset-ath79.o

drivers/reset/reset-ath79.c

0 → 100644
+128 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>



struct ath79_reset {

	struct reset_controller_dev rcdev;

	void __iomem *base;

	spinlock_t lock;

};



static int ath79_reset_update(struct reset_controller_dev *rcdev,

			unsigned long id, bool assert)

{

	struct ath79_reset *ath79_reset =

		container_of(rcdev, struct ath79_reset, rcdev);

	unsigned long flags;

	u32 val;



	spin_lock_irqsave(&ath79_reset->lock, flags);

	val = readl(ath79_reset->base);

	if (assert)

		val |= BIT(id);

	else

		val &= ~BIT(id);

	writel(val, ath79_reset->base);

	spin_unlock_irqrestore(&ath79_reset->lock, flags);



	return 0;

}



static int ath79_reset_assert(struct reset_controller_dev *rcdev,

			unsigned long id)

{

	return ath79_reset_update(rcdev, id, true);

}



static int ath79_reset_deassert(struct reset_controller_dev *rcdev,

				unsigned long id)

{

	return ath79_reset_update(rcdev, id, false);

}



static int ath79_reset_status(struct reset_controller_dev *rcdev,

			unsigned long id)

{

	struct ath79_reset *ath79_reset =

		container_of(rcdev, struct ath79_reset, rcdev);

	u32 val;



	val = readl(ath79_reset->base);



	return !!(val & BIT(id));

}



static struct reset_control_ops ath79_reset_ops = {

	.assert = ath79_reset_assert,

	.deassert = ath79_reset_deassert,

	.status = ath79_reset_status,

};



static int ath79_reset_probe(struct platform_device *pdev)

{

	struct ath79_reset *ath79_reset;

	struct resource *res;



	ath79_reset = devm_kzalloc(&pdev->dev,

				sizeof(*ath79_reset), GFP_KERNEL);

	if (!ath79_reset)

		return -ENOMEM;



	platform_set_drvdata(pdev, ath79_reset);



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(ath79_reset->base))

		return PTR_ERR(ath79_reset->base);



	ath79_reset->rcdev.ops = &ath79_reset_ops;

	ath79_reset->rcdev.owner = THIS_MODULE;

	ath79_reset->rcdev.of_node = pdev->dev.of_node;

	ath79_reset->rcdev.of_reset_n_cells = 1;

	ath79_reset->rcdev.nr_resets = 32;



	return reset_controller_register(&ath79_reset->rcdev);

}



static int ath79_reset_remove(struct platform_device *pdev)

{

	struct ath79_reset *ath79_reset = platform_get_drvdata(pdev);



	reset_controller_unregister(&ath79_reset->rcdev);



	return 0;

}



static const struct of_device_id ath79_reset_dt_ids[] = {

	{ .compatible = "qca,ar7100-reset", },

	{ },

};

MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids);



static struct platform_driver ath79_reset_driver = {

	.probe	= ath79_reset_probe,

	.remove = ath79_reset_remove,

	.driver = {

		.name		= "ath79-reset",

		.of_match_table	= ath79_reset_dt_ids,

	},

};

module_platform_driver(ath79_reset_driver);



MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");

MODULE_DESCRIPTION("AR71xx Reset Controller Driver");

MODULE_LICENSE("GPL");