diff options
Diffstat (limited to 'drivers/reset')
| -rw-r--r-- | drivers/reset/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/reset/Makefile | 1 | ||||
| -rw-r--r-- | drivers/reset/reset-gpio.c | 119 |
3 files changed, 129 insertions, 0 deletions
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 2034f69d5953..85b27c42cf65 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -66,6 +66,15 @@ config RESET_BRCMSTB_RESCAL This enables the RESCAL reset controller for SATA, PCIe0, or PCIe1 on BCM7216. +config RESET_GPIO + tristate "GPIO reset controller" + help + This enables a generic reset controller for resets attached via + GPIOs. Typically for OF platforms this driver expects "reset-gpios" + property. + + If compiled as module, it will be called reset-gpio. + config RESET_HSDK bool "Synopsys HSDK Reset Driver" depends on HAS_IOMEM diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 8270da8a4baa..fd8b49fa46fc 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o +obj-$(CONFIG_RESET_GPIO) += reset-gpio.o obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.o obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o diff --git a/drivers/reset/reset-gpio.c b/drivers/reset/reset-gpio.c new file mode 100644 index 000000000000..2290b25b6703 --- /dev/null +++ b/drivers/reset/reset-gpio.c @@ -0,0 +1,119 @@ +// 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"); |