diff options
| -rw-r--r-- | drivers/reset/core.c | 80 | ||||
| -rw-r--r-- | include/linux/reset.h | 8 |
2 files changed, 87 insertions, 1 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 18212838e4..0f900a92d0 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -9,7 +9,9 @@ * (at your option) any later version. */ #include <common.h> +#include <gpio.h> #include <malloc.h> +#include <of_gpio.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/reset.h> @@ -26,6 +28,10 @@ static LIST_HEAD(reset_controller_list); */ struct reset_control { struct reset_controller_dev *rcdev; + + int gpio; + int gpio_active_high; + struct device_d *dev; unsigned int id; }; @@ -103,6 +109,9 @@ int reset_control_assert(struct reset_control *rstc) if (!rstc) return 0; + if (rstc->gpio >= 0) + return gpio_direction_output(rstc->gpio, rstc->gpio_active_high); + if (rstc->rcdev->ops->assert) return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id); @@ -119,6 +128,9 @@ int reset_control_deassert(struct reset_control *rstc) if (!rstc) return 0; + if (rstc->gpio >= 0) + return gpio_direction_output(rstc->gpio, !rstc->gpio_active_high); + if (rstc->rcdev->ops->deassert) return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id); @@ -183,6 +195,29 @@ struct reset_control *of_reset_control_get(struct device_node *node, } EXPORT_SYMBOL_GPL(of_reset_control_get); +struct reset_control *gpio_reset_control_get(struct device_d *dev, const char *id) +{ + struct reset_control *rc; + int gpio; + enum of_gpio_flags flags; + + if (id) + return ERR_PTR(-EINVAL); + + if (!of_get_property(dev->device_node, "reset-gpios", NULL)) + return NULL; + + gpio = of_get_named_gpio_flags(dev->device_node, "reset-gpios", 0, &flags); + if (gpio < 0) + return ERR_PTR(gpio); + + rc = xzalloc(sizeof(*rc)); + rc->gpio = gpio; + rc->gpio_active_high = !(flags & OF_GPIO_ACTIVE_LOW); + + return rc; +} + /** * reset_control_get - Lookup and obtain a reference to a reset controller. * @dev: device to be reset by the controller @@ -203,6 +238,16 @@ struct reset_control *reset_control_get(struct device_d *dev, const char *id) if (IS_ERR(rstc)) return ERR_CAST(rstc); + /* + * If there is no dedicated reset controller device, check if we have + * a reset line controlled by a GPIO instead. + */ + if (!rstc) { + rstc = gpio_reset_control_get(dev, id); + if (IS_ERR(rstc)) + return ERR_CAST(rstc); + } + if (!rstc) return NULL; @@ -241,8 +286,12 @@ int device_reset(struct device_d *dev) int ret; rstc = reset_control_get(dev, NULL); - if (IS_ERR(rstc)) + if (IS_ERR(rstc)) { + if (PTR_ERR(rstc) == -ENOENT) + return 0; + return PTR_ERR(rstc); + } ret = reset_control_reset(rstc); @@ -251,3 +300,32 @@ int device_reset(struct device_d *dev) return ret; } EXPORT_SYMBOL_GPL(device_reset); + +int device_reset_us(struct device_d *dev, int us) +{ + struct reset_control *rstc; + int ret; + + rstc = reset_control_get(dev, NULL); + if (IS_ERR(rstc)) { + if (PTR_ERR(rstc) == -ENOENT) + return 0; + + return PTR_ERR(rstc); + } + + ret = reset_control_assert(rstc); + if (ret) + return ret; + + udelay(us); + + ret = reset_control_deassert(rstc); + if (ret) + return ret; + + reset_control_put(rstc); + + return ret; +} +EXPORT_SYMBOL_GPL(device_reset_us); diff --git a/include/linux/reset.h b/include/linux/reset.h index 3f810bded8..be0d1bb5a6 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -15,6 +15,8 @@ void reset_control_put(struct reset_control *rstc); int __must_check device_reset(struct device_d *dev); +int __must_check device_reset_us(struct device_d *dev, int us); + #else static inline int reset_control_reset(struct reset_control *rstc) @@ -40,6 +42,12 @@ static inline void reset_control_put(struct reset_control *rstc) WARN_ON(1); } +static inline int device_reset_us(struct device_d *dev, int us) +{ + WARN_ON(1); + return 0; +} + #endif /* CONFIG_RESET_CONTROLLER */ #endif |