linux/drivers/reset/reset-pistachio.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Pistachio SoC Reset Controller driver
*
* Copyright (C) 2015 Imagination Technologies Ltd.
*
* Author: Damien Horsley <Damien.Horsley@imgtec.com>
*/
#include <linux/init.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include <dt-bindings/reset/pistachio-resets.h>
#define PISTACHIO_SOFT_RESET 0
struct pistachio_reset_data {
struct reset_controller_dev rcdev;
struct regmap *periph_regs;
};
static inline int pistachio_reset_shift(unsigned long id)
{
switch (id) {
case PISTACHIO_RESET_I2C0:
case PISTACHIO_RESET_I2C1:
case PISTACHIO_RESET_I2C2:
case PISTACHIO_RESET_I2C3:
case PISTACHIO_RESET_I2S_IN:
case PISTACHIO_RESET_PRL_OUT:
case PISTACHIO_RESET_SPDIF_OUT:
case PISTACHIO_RESET_SPI:
case PISTACHIO_RESET_PWM_PDM:
case PISTACHIO_RESET_UART0:
case PISTACHIO_RESET_UART1:
case PISTACHIO_RESET_QSPI:
case PISTACHIO_RESET_MDC:
case PISTACHIO_RESET_SDHOST:
case PISTACHIO_RESET_ETHERNET:
case PISTACHIO_RESET_IR:
case PISTACHIO_RESET_HASH:
case PISTACHIO_RESET_TIMER:
return id;
case PISTACHIO_RESET_I2S_OUT:
case PISTACHIO_RESET_SPDIF_IN:
case PISTACHIO_RESET_EVT:
return id + 6;
case PISTACHIO_RESET_USB_H:
case PISTACHIO_RESET_USB_PR:
case PISTACHIO_RESET_USB_PHY_PR:
case PISTACHIO_RESET_USB_PHY_PON:
return id + 7;
default:
return -EINVAL;
}
}
static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct pistachio_reset_data *rd;
u32 mask;
int shift;
rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
shift = pistachio_reset_shift(id);
if (shift < 0)
return shift;
mask = BIT(shift);
return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
mask, mask);
}
static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct pistachio_reset_data *rd;
u32 mask;
int shift;
rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
shift = pistachio_reset_shift(id);
if (shift < 0)
return shift;
mask = BIT(shift);
return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
mask, 0);
}
static const struct reset_control_ops pistachio_reset_ops = {
.assert = pistachio_reset_assert,
.deassert = pistachio_reset_deassert,
};
static int pistachio_reset_probe(struct platform_device *pdev)
{
struct pistachio_reset_data *rd;
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
if (!rd)
return -ENOMEM;
rd->periph_regs = syscon_node_to_regmap(np->parent);
if (IS_ERR(rd->periph_regs))
return PTR_ERR(rd->periph_regs);
rd->rcdev.owner = THIS_MODULE;
rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
rd->rcdev.ops = &pistachio_reset_ops;
rd->rcdev.of_node = np;
return devm_reset_controller_register(dev, &rd->rcdev);
}
static const struct of_device_id pistachio_reset_dt_ids[] = {
{ .compatible = "img,pistachio-reset", },
{ /* sentinel */ },
};
static struct platform_driver pistachio_reset_driver = {
.probe = pistachio_reset_probe,
.driver = {
.name = "pistachio-reset",
.of_match_table = pistachio_reset_dt_ids,
},
};
builtin_platform_driver(pistachio_reset_driver);