u-boot/drivers/reset/reset-ast2500.c
Joel Stanley 0a8bd97f88 reset/aspeed: Implement status callback
The I2C driver shares a reset line between buses, so allow it to test
the state of the reset line before resetting it.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
2022-07-06 14:30:51 -04:00

110 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2017 Google, Inc
* Copyright 2020 ASPEED Technology Inc.
*/
#include <common.h>
#include <dm.h>
#include <log.h>
#include <misc.h>
#include <reset.h>
#include <reset-uclass.h>
#include <linux/err.h>
#include <asm/io.h>
#include <asm/arch/scu_ast2500.h>
struct ast2500_reset_priv {
struct ast2500_scu *scu;
};
static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
{
struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
struct ast2500_scu *scu = priv->scu;
debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
if (reset_ctl->id < 32)
setbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
else
setbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
return 0;
}
static int ast2500_reset_deassert(struct reset_ctl *reset_ctl)
{
struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
struct ast2500_scu *scu = priv->scu;
debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
if (reset_ctl->id < 32)
clrbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
else
clrbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
return 0;
}
static int ast2500_reset_status(struct reset_ctl *reset_ctl)
{
struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
struct ast2500_scu *scu = priv->scu;
int status;
debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
if (reset_ctl->id < 32)
status = BIT(reset_ctl->id) & readl(&scu->sysreset_ctrl1);
else
status = BIT(reset_ctl->id - 32) & readl(&scu->sysreset_ctrl2);
return !!status;
}
static int ast2500_reset_probe(struct udevice *dev)
{
int rc;
struct ast2500_reset_priv *priv = dev_get_priv(dev);
struct udevice *scu_dev;
/* get SCU base from clock device */
rc = uclass_get_device_by_driver(UCLASS_CLK,
DM_DRIVER_GET(aspeed_ast2500_scu), &scu_dev);
if (rc) {
debug("%s: clock device not found, rc=%d\n", __func__, rc);
return rc;
}
priv->scu = devfdt_get_addr_ptr(scu_dev);
if (IS_ERR_OR_NULL(priv->scu)) {
debug("%s: invalid SCU base pointer\n", __func__);
return PTR_ERR(priv->scu);
}
return 0;
}
static const struct udevice_id ast2500_reset_ids[] = {
{ .compatible = "aspeed,ast2500-reset" },
{ }
};
struct reset_ops ast2500_reset_ops = {
.rst_assert = ast2500_reset_assert,
.rst_deassert = ast2500_reset_deassert,
.rst_status = ast2500_reset_status,
};
U_BOOT_DRIVER(ast2500_reset) = {
.name = "ast2500_reset",
.id = UCLASS_RESET,
.of_match = ast2500_reset_ids,
.probe = ast2500_reset_probe,
.ops = &ast2500_reset_ops,
.priv_auto = sizeof(struct ast2500_reset_priv),
};