u-boot/drivers/reset/reset-syscon.c

82 lines
1.9 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Sean Anderson
*/
#include <common.h>
#include <dm.h>
#include <regmap.h>
#include <reset.h>
#include <reset-uclass.h>
#include <syscon.h>
#include <linux/bitops.h>
#include <linux/err.h>
struct syscon_reset_priv {
struct regmap *regmap;
uint offset;
uint mask;
bool assert_high;
};
static int syscon_reset_request(struct reset_ctl *rst)
{
struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
if (BIT(rst->id) & priv->mask)
return 0;
else
return -EINVAL;
}
static int syscon_reset_assert(struct reset_ctl *rst)
{
struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
priv->assert_high ? BIT(rst->id) : 0);
}
static int syscon_reset_deassert(struct reset_ctl *rst)
{
struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
priv->assert_high ? 0 : BIT(rst->id));
}
static const struct reset_ops syscon_reset_ops = {
.request = syscon_reset_request,
.rst_assert = syscon_reset_assert,
.rst_deassert = syscon_reset_deassert,
};
int syscon_reset_probe(struct udevice *dev)
{
struct syscon_reset_priv *priv = dev_get_priv(dev);
priv->regmap = syscon_regmap_lookup_by_phandle(dev, "regmap");
if (IS_ERR(priv->regmap))
return -ENODEV;
priv->offset = dev_read_u32_default(dev, "offset", 0);
priv->mask = dev_read_u32_default(dev, "mask", 0);
priv->assert_high = dev_read_u32_default(dev, "assert-high", true);
return 0;
}
static const struct udevice_id syscon_reset_ids[] = {
{ .compatible = "syscon-reset" },
{ },
};
U_BOOT_DRIVER(syscon_reset) = {
.name = "syscon_reset",
.id = UCLASS_RESET,
.of_match = syscon_reset_ids,
.probe = syscon_reset_probe,
.priv_auto_alloc_size = sizeof(struct syscon_reset_priv),
.ops = &syscon_reset_ops,
};