linux/drivers/reset/reset-simple.c
Rob Herring bad8a8afe1 reset: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Link: https://lore.kernel.org/r/20230714174939.4063667-1-robh@kernel.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2023-07-28 17:36:20 +02:00

205 lines
5.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Simple Reset Controller Driver
*
* Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
*
* Based on Allwinner SoCs Reset Controller driver
*
* Copyright 2013 Maxime Ripard
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/reset/reset-simple.h>
#include <linux/spinlock.h>
static inline struct reset_simple_data *
to_reset_simple_data(struct reset_controller_dev *rcdev)
{
return container_of(rcdev, struct reset_simple_data, rcdev);
}
static int reset_simple_update(struct reset_controller_dev *rcdev,
unsigned long id, bool assert)
{
struct reset_simple_data *data = to_reset_simple_data(rcdev);
int reg_width = sizeof(u32);
int bank = id / (reg_width * BITS_PER_BYTE);
int offset = id % (reg_width * BITS_PER_BYTE);
unsigned long flags;
u32 reg;
spin_lock_irqsave(&data->lock, flags);
reg = readl(data->membase + (bank * reg_width));
if (assert ^ data->active_low)
reg |= BIT(offset);
else
reg &= ~BIT(offset);
writel(reg, data->membase + (bank * reg_width));
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static int reset_simple_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
return reset_simple_update(rcdev, id, true);
}
static int reset_simple_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
return reset_simple_update(rcdev, id, false);
}
static int reset_simple_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct reset_simple_data *data = to_reset_simple_data(rcdev);
int ret;
if (!data->reset_us)
return -ENOTSUPP;
ret = reset_simple_assert(rcdev, id);
if (ret)
return ret;
usleep_range(data->reset_us, data->reset_us * 2);
return reset_simple_deassert(rcdev, id);
}
static int reset_simple_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct reset_simple_data *data = to_reset_simple_data(rcdev);
int reg_width = sizeof(u32);
int bank = id / (reg_width * BITS_PER_BYTE);
int offset = id % (reg_width * BITS_PER_BYTE);
u32 reg;
reg = readl(data->membase + (bank * reg_width));
return !(reg & BIT(offset)) ^ !data->status_active_low;
}
const struct reset_control_ops reset_simple_ops = {
.assert = reset_simple_assert,
.deassert = reset_simple_deassert,
.reset = reset_simple_reset,
.status = reset_simple_status,
};
EXPORT_SYMBOL_GPL(reset_simple_ops);
/**
* struct reset_simple_devdata - simple reset controller properties
* @reg_offset: offset between base address and first reset register.
* @nr_resets: number of resets. If not set, default to resource size in bits.
* @active_low: if true, bits are cleared to assert the reset. Otherwise, bits
* are set to assert the reset.
* @status_active_low: if true, bits read back as cleared while the reset is
* asserted. Otherwise, bits read back as set while the
* reset is asserted.
*/
struct reset_simple_devdata {
u32 reg_offset;
u32 nr_resets;
bool active_low;
bool status_active_low;
};
#define SOCFPGA_NR_BANKS 8
static const struct reset_simple_devdata reset_simple_socfpga = {
.reg_offset = 0x20,
.nr_resets = SOCFPGA_NR_BANKS * 32,
.status_active_low = true,
};
static const struct reset_simple_devdata reset_simple_active_low = {
.active_low = true,
.status_active_low = true,
};
static const struct of_device_id reset_simple_dt_ids[] = {
{ .compatible = "altr,stratix10-rst-mgr",
.data = &reset_simple_socfpga },
{ .compatible = "st,stm32-rcc", },
{ .compatible = "allwinner,sun6i-a31-clock-reset",
.data = &reset_simple_active_low },
{ .compatible = "zte,zx296718-reset",
.data = &reset_simple_active_low },
{ .compatible = "aspeed,ast2400-lpc-reset" },
{ .compatible = "aspeed,ast2500-lpc-reset" },
{ .compatible = "aspeed,ast2600-lpc-reset" },
{ .compatible = "bitmain,bm1880-reset",
.data = &reset_simple_active_low },
{ .compatible = "brcm,bcm4908-misc-pcie-reset",
.data = &reset_simple_active_low },
{ .compatible = "snps,dw-high-reset" },
{ .compatible = "snps,dw-low-reset",
.data = &reset_simple_active_low },
{ /* sentinel */ },
};
static int reset_simple_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct reset_simple_devdata *devdata;
struct reset_simple_data *data;
void __iomem *membase;
struct resource *res;
u32 reg_offset = 0;
devdata = of_device_get_match_data(dev);
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
membase = devm_ioremap_resource(dev, res);
if (IS_ERR(membase))
return PTR_ERR(membase);
spin_lock_init(&data->lock);
data->membase = membase;
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE;
data->rcdev.ops = &reset_simple_ops;
data->rcdev.of_node = dev->of_node;
if (devdata) {
reg_offset = devdata->reg_offset;
if (devdata->nr_resets)
data->rcdev.nr_resets = devdata->nr_resets;
data->active_low = devdata->active_low;
data->status_active_low = devdata->status_active_low;
}
data->membase += reg_offset;
return devm_reset_controller_register(dev, &data->rcdev);
}
static struct platform_driver reset_simple_driver = {
.probe = reset_simple_probe,
.driver = {
.name = "simple-reset",
.of_match_table = reset_simple_dt_ids,
},
};
builtin_platform_driver(reset_simple_driver);