155 строки
4.0 KiB
C
155 строки
4.0 KiB
C
/*
|
|
* Socfpga Reset Controller Driver
|
|
*
|
|
* Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
|
|
*
|
|
* based on
|
|
* Allwinner SoCs Reset Controller driver
|
|
*
|
|
* Copyright 2013 Maxime Ripard
|
|
*
|
|
* Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/init.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/types.h>
|
|
|
|
#define BANK_INCREMENT 4
|
|
#define NR_BANKS 8
|
|
|
|
struct socfpga_reset_data {
|
|
spinlock_t lock;
|
|
void __iomem *membase;
|
|
struct reset_controller_dev rcdev;
|
|
};
|
|
|
|
static int socfpga_reset_assert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct socfpga_reset_data *data = container_of(rcdev,
|
|
struct socfpga_reset_data,
|
|
rcdev);
|
|
int bank = id / BITS_PER_LONG;
|
|
int offset = id % BITS_PER_LONG;
|
|
unsigned long flags;
|
|
u32 reg;
|
|
|
|
spin_lock_irqsave(&data->lock, flags);
|
|
|
|
reg = readl(data->membase + (bank * BANK_INCREMENT));
|
|
writel(reg | BIT(offset), data->membase + (bank * BANK_INCREMENT));
|
|
spin_unlock_irqrestore(&data->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int socfpga_reset_deassert(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct socfpga_reset_data *data = container_of(rcdev,
|
|
struct socfpga_reset_data,
|
|
rcdev);
|
|
|
|
int bank = id / BITS_PER_LONG;
|
|
int offset = id % BITS_PER_LONG;
|
|
unsigned long flags;
|
|
u32 reg;
|
|
|
|
spin_lock_irqsave(&data->lock, flags);
|
|
|
|
reg = readl(data->membase + (bank * BANK_INCREMENT));
|
|
writel(reg & ~BIT(offset), data->membase + (bank * BANK_INCREMENT));
|
|
|
|
spin_unlock_irqrestore(&data->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int socfpga_reset_status(struct reset_controller_dev *rcdev,
|
|
unsigned long id)
|
|
{
|
|
struct socfpga_reset_data *data = container_of(rcdev,
|
|
struct socfpga_reset_data, rcdev);
|
|
int bank = id / BITS_PER_LONG;
|
|
int offset = id % BITS_PER_LONG;
|
|
u32 reg;
|
|
|
|
reg = readl(data->membase + (bank * BANK_INCREMENT));
|
|
|
|
return !(reg & BIT(offset));
|
|
}
|
|
|
|
static const struct reset_control_ops socfpga_reset_ops = {
|
|
.assert = socfpga_reset_assert,
|
|
.deassert = socfpga_reset_deassert,
|
|
.status = socfpga_reset_status,
|
|
};
|
|
|
|
static int socfpga_reset_probe(struct platform_device *pdev)
|
|
{
|
|
struct socfpga_reset_data *data;
|
|
struct resource *res;
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev->of_node;
|
|
u32 modrst_offset;
|
|
|
|
/*
|
|
* The binding was mainlined without the required property.
|
|
* Do not continue, when we encounter an old DT.
|
|
*/
|
|
if (!of_find_property(pdev->dev.of_node, "#reset-cells", NULL)) {
|
|
dev_err(&pdev->dev, "%s missing #reset-cells property\n",
|
|
pdev->dev.of_node->full_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
data->membase = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(data->membase))
|
|
return PTR_ERR(data->membase);
|
|
|
|
if (of_property_read_u32(np, "altr,modrst-offset", &modrst_offset)) {
|
|
dev_warn(dev, "missing altr,modrst-offset property, assuming 0x10!\n");
|
|
modrst_offset = 0x10;
|
|
}
|
|
data->membase += modrst_offset;
|
|
|
|
spin_lock_init(&data->lock);
|
|
|
|
data->rcdev.owner = THIS_MODULE;
|
|
data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG;
|
|
data->rcdev.ops = &socfpga_reset_ops;
|
|
data->rcdev.of_node = pdev->dev.of_node;
|
|
|
|
return devm_reset_controller_register(dev, &data->rcdev);
|
|
}
|
|
|
|
static const struct of_device_id socfpga_reset_dt_ids[] = {
|
|
{ .compatible = "altr,rst-mgr", },
|
|
{ /* sentinel */ },
|
|
};
|
|
|
|
static struct platform_driver socfpga_reset_driver = {
|
|
.probe = socfpga_reset_probe,
|
|
.driver = {
|
|
.name = "socfpga-reset",
|
|
.of_match_table = socfpga_reset_dt_ids,
|
|
},
|
|
};
|
|
builtin_platform_driver(socfpga_reset_driver);
|