Commit aac02543 authored by Álvaro Fernández Rojas's avatar Álvaro Fernández Rojas Committed by Thomas Bogendoerfer
Browse files

reset: add BCM6345 reset controller driver 



Add support for resetting blocks through the Linux reset controller
subsystem for BCM63xx SoCs.

Signed-off-by: default avatarÁlvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <F.fainelli@gmail.com>
Reviewed-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent 10c1e714

drivers/reset/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -35,6 +35,13 @@ config RESET_AXS10X 
	help

	  This enables the reset controller driver for AXS10x.



config RESET_BCM6345

	bool "BCM6345 Reset Controller"

	depends on BMIPS_GENERIC || COMPILE_TEST

	default BMIPS_GENERIC

	help

	  This enables the reset controller driver for BCM6345 SoCs.



config RESET_BERLIN

	bool "Berlin Reset Driver" if COMPILE_TEST

	default ARCH_BERLIN

drivers/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/ 
obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o

obj-$(CONFIG_RESET_ATH79) += reset-ath79.o

obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o

obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o

obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o

obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o

obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o

drivers/reset/reset-bcm6345.c

0 → 100644
+135 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * BCM6345 Reset Controller Driver

 *

 * Copyright (C) 2020 Álvaro Fernández Rojas <noltari@gmail.com>

 */



#include <linux/delay.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/mod_devicetable.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>



#define BCM6345_RESET_NUM		32

#define BCM6345_RESET_SLEEP_MIN_US	10000

#define BCM6345_RESET_SLEEP_MAX_US	20000



struct bcm6345_reset {

	struct reset_controller_dev rcdev;

	void __iomem *base;

	spinlock_t lock;

};



static inline struct bcm6345_reset *

to_bcm6345_reset(struct reset_controller_dev *rcdev)

{

	return container_of(rcdev, struct bcm6345_reset, rcdev);

}



static int bcm6345_reset_update(struct reset_controller_dev *rcdev,

				unsigned long id, bool assert)

{

	struct bcm6345_reset *bcm6345_reset = to_bcm6345_reset(rcdev);

	unsigned long flags;

	uint32_t val;



	spin_lock_irqsave(&bcm6345_reset->lock, flags);

	val = __raw_readl(bcm6345_reset->base);

	if (assert)

		val &= ~BIT(id);

	else

		val |= BIT(id);

	__raw_writel(val, bcm6345_reset->base);

	spin_unlock_irqrestore(&bcm6345_reset->lock, flags);



	return 0;

}



static int bcm6345_reset_assert(struct reset_controller_dev *rcdev,

				unsigned long id)

{

	return bcm6345_reset_update(rcdev, id, true);

}



static int bcm6345_reset_deassert(struct reset_controller_dev *rcdev,

				  unsigned long id)

{

	return bcm6345_reset_update(rcdev, id, false);

}



static int bcm6345_reset_reset(struct reset_controller_dev *rcdev,

			       unsigned long id)

{

	bcm6345_reset_update(rcdev, id, true);

	usleep_range(BCM6345_RESET_SLEEP_MIN_US,

		     BCM6345_RESET_SLEEP_MAX_US);



	bcm6345_reset_update(rcdev, id, false);

	/*

	 * Ensure component is taken out reset state by sleeping also after

	 * deasserting the reset. Otherwise, the component may not be ready

	 * for operation.

	 */

	usleep_range(BCM6345_RESET_SLEEP_MIN_US,

		     BCM6345_RESET_SLEEP_MAX_US);



	return 0;

}



static int bcm6345_reset_status(struct reset_controller_dev *rcdev,

				unsigned long id)

{

	struct bcm6345_reset *bcm6345_reset = to_bcm6345_reset(rcdev);



	return !(__raw_readl(bcm6345_reset->base) & BIT(id));

}



static struct reset_control_ops bcm6345_reset_ops = {

	.assert = bcm6345_reset_assert,

	.deassert = bcm6345_reset_deassert,

	.reset = bcm6345_reset_reset,

	.status = bcm6345_reset_status,

};



static int bcm6345_reset_probe(struct platform_device *pdev)

{

	struct bcm6345_reset *bcm6345_reset;



	bcm6345_reset = devm_kzalloc(&pdev->dev,

				     sizeof(*bcm6345_reset), GFP_KERNEL);

	if (!bcm6345_reset)

		return -ENOMEM;



	platform_set_drvdata(pdev, bcm6345_reset);



	bcm6345_reset->base = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(bcm6345_reset->base))

		return PTR_ERR(bcm6345_reset->base);



	spin_lock_init(&bcm6345_reset->lock);

	bcm6345_reset->rcdev.ops = &bcm6345_reset_ops;

	bcm6345_reset->rcdev.owner = THIS_MODULE;

	bcm6345_reset->rcdev.of_node = pdev->dev.of_node;

	bcm6345_reset->rcdev.of_reset_n_cells = 1;

	bcm6345_reset->rcdev.nr_resets = BCM6345_RESET_NUM;



	return devm_reset_controller_register(&pdev->dev,

					      &bcm6345_reset->rcdev);

}



static const struct of_device_id bcm6345_reset_of_match[] = {

	{ .compatible = "brcm,bcm6345-reset" },

	{ /* sentinel */ },

};



static struct platform_driver bcm6345_reset_driver = {

	.probe = bcm6345_reset_probe,

	.driver	= {

		.name = "bcm6345-reset",

		.of_match_table = bcm6345_reset_of_match,

		.suppress_bind_attrs = true,

	},

};

builtin_platform_driver(bcm6345_reset_driver);