| // 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"); |