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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Renesas Electronics Corporation
*/
#include <linux/delay.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#define PWC_PWCRST 0x00
#define PWC_PWCCKEN 0x04
#define PWC_PWCCTL 0x50
#define PWC_GPIO 0x80
#define PWC_PWCRST_RSTSOFTAX 0x1
#define PWC_PWCCKEN_ENGCKMAIN 0x1
#define PWC_PWCCTL_PWOFF 0x1
struct rzv2m_pwc_priv {
void __iomem *base;
struct device *dev;
struct gpio_chip gp;
DECLARE_BITMAP(ch_en_bits, 2);
};
static void rzv2m_pwc_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
u32 reg;
/* BIT 16 enables write to BIT 0, and BIT 17 enables write to BIT 1 */
reg = BIT(offset + 16);
if (value)
reg |= BIT(offset);
writel(reg, priv->base + PWC_GPIO);
assign_bit(offset, priv->ch_en_bits, value);
}
static int rzv2m_pwc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
return test_bit(offset, priv->ch_en_bits);
}
static int rzv2m_pwc_gpio_direction_output(struct gpio_chip *gc,
unsigned int nr, int value)
{
if (nr > 1)
return -EINVAL;
rzv2m_pwc_gpio_set(gc, nr, value);
return 0;
}
static const struct gpio_chip rzv2m_pwc_gc = {
.label = "gpio_rzv2m_pwc",
.owner = THIS_MODULE,
.get = rzv2m_pwc_gpio_get,
.set = rzv2m_pwc_gpio_set,
.direction_output = rzv2m_pwc_gpio_direction_output,
.can_sleep = false,
.ngpio = 2,
.base = -1,
};
static int rzv2m_pwc_poweroff(struct sys_off_data *data)
{
struct rzv2m_pwc_priv *priv = data->cb_data;
writel(PWC_PWCRST_RSTSOFTAX, priv->base + PWC_PWCRST);
writel(PWC_PWCCKEN_ENGCKMAIN, priv->base + PWC_PWCCKEN);
writel(PWC_PWCCTL_PWOFF, priv->base + PWC_PWCCTL);
mdelay(150);
dev_err(priv->dev, "Failed to power off the system");
return NOTIFY_DONE;
}
static int rzv2m_pwc_probe(struct platform_device *pdev)
{
struct rzv2m_pwc_priv *priv;
int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
/*
* The register used by this driver cannot be read, therefore set the
* outputs to their default values and initialize priv->ch_en_bits
* accordingly. BIT 16 enables write to BIT 0, BIT 17 enables write to
* BIT 1, and the default value of both BIT 0 and BIT 1 is 0.
*/
writel(BIT(17) | BIT(16), priv->base + PWC_GPIO);
bitmap_zero(priv->ch_en_bits, 2);
priv->gp = rzv2m_pwc_gc;
priv->gp.parent = pdev->dev.parent;
priv->gp.fwnode = dev_fwnode(&pdev->dev);
ret = devm_gpiochip_add_data(&pdev->dev, &priv->gp, priv);
if (ret)
return ret;
if (device_property_read_bool(&pdev->dev, "renesas,rzv2m-pwc-power"))
ret = devm_register_power_off_handler(&pdev->dev,
rzv2m_pwc_poweroff, priv);
return ret;
}
static const struct of_device_id rzv2m_pwc_of_match[] = {
{ .compatible = "renesas,rzv2m-pwc" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rzv2m_pwc_of_match);
static struct platform_driver rzv2m_pwc_driver = {
.probe = rzv2m_pwc_probe,
.driver = {
.name = "rzv2m_pwc",
.of_match_table = rzv2m_pwc_of_match,
},
};
module_platform_driver(rzv2m_pwc_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Fabrizio Castro <castro.fabrizio.jz@renesas.com>");
MODULE_DESCRIPTION("Renesas RZ/V2M PWC driver");
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