u-boot/drivers/reset/reset-at91.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Support for Atmel/Microchip Reset Controller.
*
* Copyright (C) 2022 Microchip Technology Inc. and its subsidiaries
*
* Author: Sergiu Moga <sergiu.moga@microchip.com>
*/
#include <clk.h>
#include <asm/io.h>
#include <dm.h>
#include <dm/lists.h>
#include <reset-uclass.h>
#include <asm/arch/at91_rstc.h>
#include <dt-bindings/reset/sama7g5-reset.h>
struct at91_reset {
void __iomem *dev_base;
struct at91_reset_data *data;
};
struct at91_reset_data {
u32 n_device_reset;
u8 device_reset_min_id;
u8 device_reset_max_id;
};
static const struct at91_reset_data sama7g5_data = {
.n_device_reset = 3,
.device_reset_min_id = SAMA7G5_RESET_USB_PHY1,
.device_reset_max_id = SAMA7G5_RESET_USB_PHY3,
};
static int at91_rst_update(struct at91_reset *reset, unsigned long id,
bool assert)
{
u32 val;
if (!reset->dev_base)
return 0;
val = readl(reset->dev_base);
if (assert)
val |= BIT(id);
else
val &= ~BIT(id);
writel(val, reset->dev_base);
return 0;
}
static int at91_reset_of_xlate(struct reset_ctl *reset_ctl,
struct ofnode_phandle_args *args)
{
struct at91_reset *reset = dev_get_priv(reset_ctl->dev);
if (!reset->data->n_device_reset ||
args->args[0] < reset->data->device_reset_min_id ||
args->args[0] > reset->data->device_reset_max_id)
return -EINVAL;
reset_ctl->id = args->args[0];
return 0;
}
static int at91_rst_assert(struct reset_ctl *reset_ctl)
{
struct at91_reset *reset = dev_get_priv(reset_ctl->dev);
return at91_rst_update(reset, reset_ctl->id, true);
}
static int at91_rst_deassert(struct reset_ctl *reset_ctl)
{
struct at91_reset *reset = dev_get_priv(reset_ctl->dev);
return at91_rst_update(reset, reset_ctl->id, false);
}
struct reset_ops at91_reset_ops = {
.of_xlate = at91_reset_of_xlate,
.rst_assert = at91_rst_assert,
.rst_deassert = at91_rst_deassert,
};
static int at91_reset_probe(struct udevice *dev)
{
struct at91_reset *reset = dev_get_priv(dev);
struct clk sclk;
int ret;
reset->data = (struct at91_reset_data *)dev_get_driver_data(dev);
reset->dev_base = dev_remap_addr_index(dev, 1);
if (reset->data && reset->data->n_device_reset && !reset->dev_base)
return -EINVAL;
ret = clk_get_by_index(dev, 0, &sclk);
if (ret)
return ret;
return clk_prepare_enable(&sclk);
}
static int at91_reset_bind(struct udevice *dev)
{
struct udevice *at91_sysreset;
if (CONFIG_IS_ENABLED(SYSRESET_AT91))
return device_bind_driver_to_node(dev, "at91_sysreset",
"at91_sysreset",
dev_ofnode(dev),
&at91_sysreset);
return 0;
}
static const struct udevice_id at91_reset_ids[] = {
{
.compatible = "microchip,sama7g5-rstc",
.data = (ulong)&sama7g5_data,
},
{
.compatible = "atmel,sama5d3-rstc",
},
{
.compatible = "microchip,sam9x60-rstc",
},
{ }
};
U_BOOT_DRIVER(at91_reset) = {
.name = "at91_reset",
.id = UCLASS_RESET,
.of_match = at91_reset_ids,
.bind = at91_reset_bind,
.probe = at91_reset_probe,
.priv_auto = sizeof(struct at91_reset),
.ops = &at91_reset_ops,
};