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// SPDX-License-Identifier: GPL-2.0
#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
struct reset_gpio_priv {
struct reset_controller_dev rc;
struct gpio_desc *reset;
};
static inline struct reset_gpio_priv
*rc_to_reset_gpio(struct reset_controller_dev *rc)
{
return container_of(rc, struct reset_gpio_priv, rc);
}
static int reset_gpio_assert(struct reset_controller_dev *rc, unsigned long id)
{
struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
gpiod_set_value_cansleep(priv->reset, 1);
return 0;
}
static int reset_gpio_deassert(struct reset_controller_dev *rc,
unsigned long id)
{
struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
gpiod_set_value_cansleep(priv->reset, 0);
return 0;
}
static int reset_gpio_status(struct reset_controller_dev *rc, unsigned long id)
{
struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
return gpiod_get_value_cansleep(priv->reset);
}
static const struct reset_control_ops reset_gpio_ops = {
.assert = reset_gpio_assert,
.deassert = reset_gpio_deassert,
.status = reset_gpio_status,
};
static int reset_gpio_of_xlate(struct reset_controller_dev *rcdev,
const struct of_phandle_args *reset_spec)
{
return reset_spec->args[0];
}
static void reset_gpio_of_node_put(void *data)
{
of_node_put(data);
}
static int reset_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct of_phandle_args *platdata = dev_get_platdata(dev);
struct reset_gpio_priv *priv;
int ret;
if (!platdata)
return -EINVAL;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, &priv->rc);
priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(priv->reset))
return dev_err_probe(dev, PTR_ERR(priv->reset),
"Could not get reset gpios\n");
priv->rc.ops = &reset_gpio_ops;
priv->rc.owner = THIS_MODULE;
priv->rc.dev = dev;
priv->rc.of_args = platdata;
ret = devm_add_action_or_reset(dev, reset_gpio_of_node_put,
priv->rc.of_node);
if (ret)
return ret;
/* Cells to match GPIO specifier, but it's not really used */
priv->rc.of_reset_n_cells = 2;
priv->rc.of_xlate = reset_gpio_of_xlate;
priv->rc.nr_resets = 1;
return devm_reset_controller_register(dev, &priv->rc);
}
static const struct platform_device_id reset_gpio_ids[] = {
{ .name = "reset-gpio", },
{}
};
MODULE_DEVICE_TABLE(platform, reset_gpio_ids);
static struct platform_driver reset_gpio_driver = {
.probe = reset_gpio_probe,
.id_table = reset_gpio_ids,
.driver = {
.name = "reset-gpio",
},
};
module_platform_driver(reset_gpio_driver);
MODULE_AUTHOR("Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>");
MODULE_DESCRIPTION("Generic GPIO reset driver");
MODULE_LICENSE("GPL");
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