mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
77750bc089
Add support for resetting blocks through the Linux reset controller subsystem when reset lines are provided through a SW_INIT-style reset controller on Broadcom STB SoCs. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
132 lines
3.5 KiB
C
132 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Broadcom STB generic reset controller for SW_INIT style reset controller
|
|
*
|
|
* Author: Florian Fainelli <f.fainelli@gmail.com>
|
|
* Copyright (C) 2018 Broadcom
|
|
*/
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/types.h>
|
|
|
|
struct brcmstb_reset {
|
|
void __iomem *base;
|
|
struct reset_controller_dev rcdev;
|
|
};
|
|
|
|
#define SW_INIT_SET 0x00
|
|
#define SW_INIT_CLEAR 0x04
|
|
#define SW_INIT_STATUS 0x08
|
|
|
|
#define SW_INIT_BIT(id) BIT((id) & 0x1f)
|
|
#define SW_INIT_BANK(id) ((id) >> 5)
|
|
|
|
/* A full bank contains extra registers that we are not utilizing but still
|
|
* qualify as a single bank.
|
|
*/
|
|
#define SW_INIT_BANK_SIZE 0x18
|
|
|
|
static inline
|
|
struct brcmstb_reset *to_brcmstb(struct reset_controller_dev *rcdev)
|
|
{
|
|
return container_of(rcdev, struct brcmstb_reset, rcdev);
|
|
}
|
|
|
|
static int brcmstb_reset_assert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
|
|
struct brcmstb_reset *priv = to_brcmstb(rcdev);
|
|
|
|
writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_SET);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int brcmstb_reset_deassert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
|
|
struct brcmstb_reset *priv = to_brcmstb(rcdev);
|
|
|
|
writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_CLEAR);
|
|
/* Maximum reset delay after de-asserting a line and seeing block
|
|
* operation is typically 14us for the worst case, build some slack
|
|
* here.
|
|
*/
|
|
usleep_range(100, 200);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int brcmstb_reset_status(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
|
|
struct brcmstb_reset *priv = to_brcmstb(rcdev);
|
|
|
|
return readl_relaxed(priv->base + off + SW_INIT_STATUS) &
|
|
SW_INIT_BIT(id);
|
|
}
|
|
|
|
static const struct reset_control_ops brcmstb_reset_ops = {
|
|
.assert = brcmstb_reset_assert,
|
|
.deassert = brcmstb_reset_deassert,
|
|
.status = brcmstb_reset_status,
|
|
};
|
|
|
|
static int brcmstb_reset_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *kdev = &pdev->dev;
|
|
struct brcmstb_reset *priv;
|
|
struct resource *res;
|
|
|
|
priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!IS_ALIGNED(res->start, SW_INIT_BANK_SIZE) ||
|
|
!IS_ALIGNED(resource_size(res), SW_INIT_BANK_SIZE)) {
|
|
dev_err(kdev, "incorrect register range\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
priv->base = devm_ioremap_resource(kdev, res);
|
|
if (IS_ERR(priv->base))
|
|
return PTR_ERR(priv->base);
|
|
|
|
dev_set_drvdata(kdev, priv);
|
|
|
|
priv->rcdev.owner = THIS_MODULE;
|
|
priv->rcdev.nr_resets = DIV_ROUND_DOWN_ULL(resource_size(res),
|
|
SW_INIT_BANK_SIZE) * 32;
|
|
priv->rcdev.ops = &brcmstb_reset_ops;
|
|
priv->rcdev.of_node = kdev->of_node;
|
|
/* Use defaults: 1 cell and simple xlate function */
|
|
|
|
return devm_reset_controller_register(kdev, &priv->rcdev);
|
|
}
|
|
|
|
static const struct of_device_id brcmstb_reset_of_match[] = {
|
|
{ .compatible = "brcm,brcmstb-reset" },
|
|
{ /* sentinel */ }
|
|
};
|
|
|
|
static struct platform_driver brcmstb_reset_driver = {
|
|
.probe = brcmstb_reset_probe,
|
|
.driver = {
|
|
.name = "brcmstb-reset",
|
|
.of_match_table = brcmstb_reset_of_match,
|
|
},
|
|
};
|
|
module_platform_driver(brcmstb_reset_driver);
|
|
|
|
MODULE_AUTHOR("Broadcom");
|
|
MODULE_DESCRIPTION("Broadcom STB reset controller");
|
|
MODULE_LICENSE("GPL");
|