reset: add the Berlin reset controller driver

obj-$(CONFIG_RESET_CONTROLLER) += core.o

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/

/*

 * Copyright (C) 2014 Marvell Technology Group Ltd.

 *

 * Antoine Tenart <antoine.tenart@free-electrons.com>

 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

#include <linux/delay.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>

#include <linux/slab.h>

#include <linux/types.h>

#define BERLIN_MAX_RESETS	32

#define to_berlin_reset_priv(p)		\

	container_of((p), struct berlin_reset_priv, rcdev)

struct berlin_reset_priv {

	void __iomem			*base;

	unsigned int			size;

	struct reset_controller_dev	rcdev;

};

static int berlin_reset_reset(struct reset_controller_dev *rcdev,

			      unsigned long id)

{

	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);

	int offset = id >> 8;

	int mask = BIT(id & 0x1f);

	writel(mask, priv->base + offset);

	/* let the reset be effective */

	udelay(10);

	return 0;

}

static struct reset_control_ops berlin_reset_ops = {

	.reset	= berlin_reset_reset,

};

static int berlin_reset_xlate(struct reset_controller_dev *rcdev,

			      const struct of_phandle_args *reset_spec)

{

	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);

	unsigned offset, bit;

	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))

		return -EINVAL;

	offset = reset_spec->args[0];

	bit = reset_spec->args[1];

	if (offset >= priv->size)

		return -EINVAL;

	if (bit >= BERLIN_MAX_RESETS)

		return -EINVAL;

	return (offset << 8) | bit;

}

static int __berlin_reset_init(struct device_node *np)

{

	struct berlin_reset_priv *priv;

	struct resource res;

	resource_size_t size;

	int ret;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;

	ret = of_address_to_resource(np, 0, &res);

	if (ret)

		goto err;

	size = resource_size(&res);

	priv->base = ioremap(res.start, size);

	if (!priv->base) {

		ret = -ENOMEM;

		goto err;

	}

	priv->size = size;

	priv->rcdev.owner = THIS_MODULE;

	priv->rcdev.ops = &berlin_reset_ops;

	priv->rcdev.of_node = np;

	priv->rcdev.of_reset_n_cells = 2;

	priv->rcdev.of_xlate = berlin_reset_xlate;

	reset_controller_register(&priv->rcdev);

	return 0;

err:

	kfree(priv);

	return ret;

}

static const struct of_device_id berlin_reset_of_match[] __initconst = {

	{ .compatible = "marvell,berlin2-chip-ctrl" },

	{ .compatible = "marvell,berlin2cd-chip-ctrl" },

	{ .compatible = "marvell,berlin2q-chip-ctrl" },

	{ },

};

static int __init berlin_reset_init(void)

{

	struct device_node *np;

	int ret;

	for_each_matching_node(np, berlin_reset_of_match) {

		ret = __berlin_reset_init(np);

		if (ret)

			return ret;

	}

	return 0;

}

arch_initcall(berlin_reset_init);