038b13ee81
This patch adds a generic reset driver. It is designed to be useful when one has a register in a regmap which contains bits that reset other devices. I thought this seemed like a very generic use, so here is a generic driver. The overall structure has been modeled on the syscon-reboot driver. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
// 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,
|
|
};
|