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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020 Sifive, Inc.
* Author: Sagar Kadam <sagar.kadam@sifive.com>
*/
#include <dm.h>
#include <reset-uclass.h>
#include <asm/io.h>
#include <dm/device_compat.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <linux/bitops.h>
#define PRCI_RESETREG_OFFSET 0x28
struct sifive_reset_priv {
void *base;
/* number of reset signals */
int nr_reset;
};
static int sifive_rst_trigger(struct reset_ctl *rst, bool level)
{
struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
int id = rst->id;
int regval = readl(priv->base + PRCI_RESETREG_OFFSET);
/* Derive bitposition from rst id */
if (level)
/* Reset deassert */
regval |= BIT(id);
else
/* Reset assert */
regval &= ~BIT(id);
writel(regval, priv->base + PRCI_RESETREG_OFFSET);
return 0;
}
static int sifive_reset_assert(struct reset_ctl *rst)
{
return sifive_rst_trigger(rst, false);
}
static int sifive_reset_deassert(struct reset_ctl *rst)
{
return sifive_rst_trigger(rst, true);
}
static int sifive_reset_request(struct reset_ctl *rst)
{
struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
debug("%s(rst=%p) (dev=%p, id=%lu) (nr_reset=%d)\n", __func__,
rst, rst->dev, rst->id, priv->nr_reset);
if (rst->id > priv->nr_reset)
return -EINVAL;
return 0;
}
static int sifive_reset_probe(struct udevice *dev)
{
struct sifive_reset_priv *priv = dev_get_priv(dev);
priv->base = dev_remap_addr(dev);
if (!priv->base)
return -ENOMEM;
return 0;
}
int sifive_reset_bind(struct udevice *dev, ulong count)
{
struct udevice *rst_dev;
struct sifive_reset_priv *priv;
int ret;
ret = device_bind_driver_to_node(dev, "sifive-reset", "reset",
dev_ofnode(dev), &rst_dev);
if (ret) {
dev_err(dev, "failed to bind sifive_reset driver (ret=%d)\n", ret);
return ret;
}
priv = malloc(sizeof(struct sifive_reset_priv));
priv->nr_reset = count;
dev_set_priv(rst_dev, priv);
return 0;
}
const struct reset_ops sifive_reset_ops = {
.request = sifive_reset_request,
.rst_assert = sifive_reset_assert,
.rst_deassert = sifive_reset_deassert,
};
U_BOOT_DRIVER(sifive_reset) = {
.name = "sifive-reset",
.id = UCLASS_RESET,
.ops = &sifive_reset_ops,
.probe = sifive_reset_probe,
.priv_auto = sizeof(struct sifive_reset_priv),
};
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