diff options
Diffstat (limited to 'drivers/gpio/gpio-uclass.c')
| -rw-r--r-- | drivers/gpio/gpio-uclass.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c new file mode 100644 index 0000000..56bfd11 --- /dev/null +++ b/drivers/gpio/gpio-uclass.c @@ -0,0 +1,266 @@ +/* + * Copyright (c) 2013 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <asm/gpio.h> + +/** + * gpio_to_device() - Convert global GPIO number to device, number + * gpio: The numeric representation of the GPIO + * + * Convert the GPIO number to an entry in the list of GPIOs + * or GPIO blocks registered with the GPIO controller. Returns + * entry on success, NULL on error. + */ +static int gpio_to_device(unsigned int gpio, struct device **devp, + unsigned int *offset) +{ + struct gpio_dev_priv *uc_priv; + struct device *dev; + int ret; + + for (ret = uclass_first_device(UCLASS_GPIO, &dev); + dev; + ret = uclass_next_device(&dev)) { + uc_priv = dev->uclass_priv; + if (gpio >= uc_priv->gpio_base && + gpio < uc_priv->gpio_base + uc_priv->gpio_count) { + *devp = dev; + *offset = gpio - uc_priv->gpio_base; + return 0; + } + } + + /* No such GPIO */ + return ret ? ret : -EINVAL; +} + +int gpio_lookup_name(const char *name, struct device **devp, + unsigned int *offsetp, unsigned int *gpiop) +{ + struct gpio_dev_priv *uc_priv; + struct device *dev; + int ret; + + if (devp) + *devp = NULL; + for (ret = uclass_first_device(UCLASS_GPIO, &dev); + dev; + ret = uclass_next_device(&dev)) { + ulong offset; + int len; + + uc_priv = dev->uclass_priv; + len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0; + + if (!strncmp(name, uc_priv->bank_name, len)) { + if (strict_strtoul(name + len, 10, &offset)) + continue; + if (devp) + *devp = dev; + if (offsetp) + *offsetp = offset; + if (gpiop) + *gpiop = uc_priv->gpio_base + offset; + return 0; + } + } + + return ret ? ret : -EINVAL; +} + +/** + * gpio_request() - [COMPAT] Request GPIO + * gpio: GPIO number + * label: Name for the requested GPIO + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns 0 on success, negative value on error. + */ +int gpio_request(unsigned gpio, const char *label) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + if (!gpio_get_ops(dev)->request) + return 0; + + return gpio_get_ops(dev)->request(dev, offset, label); +} + +/** + * gpio_free() - [COMPAT] Relinquish GPIO + * gpio: GPIO number + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns 0 on success, negative value on error. + */ +int gpio_free(unsigned gpio) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + if (!gpio_get_ops(dev)->free) + return 0; + return gpio_get_ops(dev)->free(dev, offset); +} + +/** + * gpio_direction_input() - [COMPAT] Set GPIO direction to input + * gpio: GPIO number + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns 0 on success, negative value on error. + */ +int gpio_direction_input(unsigned gpio) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + return gpio_get_ops(dev)->direction_input(dev, offset); +} + +/** + * gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value + * gpio: GPIO number + * value: Logical value to be set on the GPIO pin + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns 0 on success, negative value on error. + */ +int gpio_direction_output(unsigned gpio, int value) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + return gpio_get_ops(dev)->direction_output(dev, offset, value); +} + +/** + * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value + * gpio: GPIO number + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns the value of the GPIO pin, or negative value + * on error. + */ +int gpio_get_value(unsigned gpio) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + return gpio_get_ops(dev)->get_value(dev, offset); +} + +/** + * gpio_set_value() - [COMPAT] Configure logical value on GPIO pin + * gpio: GPIO number + * value: Logical value to be set on the GPIO pin. + * + * This function implements the API that's compatible with current + * GPIO API used in U-Boot. The request is forwarded to particular + * GPIO driver. Returns 0 on success, negative value on error. + */ +int gpio_set_value(unsigned gpio, int value) +{ + unsigned int offset; + struct device *dev; + int ret; + + ret = gpio_to_device(gpio, &dev, &offset); + if (ret) + return ret; + + return gpio_get_ops(dev)->set_value(dev, offset, value); +} + +const char *gpio_get_bank_info(struct device *dev, int *bit_count) +{ + struct gpio_dev_priv *priv; + + /* Must be called on an active device */ + priv = dev->uclass_priv; + assert(priv); + + *bit_count = priv->gpio_count; + return priv->bank_name; +} + +/* We need to renumber the GPIOs when any driver is probed/removed */ +static int gpio_renumber(void) +{ + struct gpio_dev_priv *uc_priv; + struct device *dev; + struct uclass *uc; + unsigned base; + int ret; + + ret = uclass_get(UCLASS_GPIO, &uc); + if (ret) + return ret; + + /* Ensure that we have a base for each bank */ + base = 0; + uclass_foreach_dev(dev, uc) { + if (device_active(dev)) { + uc_priv = dev->uclass_priv; + uc_priv->gpio_base = base; + base += uc_priv->gpio_count; + } + } + + return 0; +} + +static int gpio_post_probe(struct device *dev) +{ + return gpio_renumber(); +} + +static int gpio_pre_remove(struct device *dev) +{ + return gpio_renumber(); +} + +UCLASS_DRIVER(gpio) = { + .id = UCLASS_GPIO, + .name = "gpio", + .post_probe = gpio_post_probe, + .pre_remove = gpio_pre_remove, + .per_device_auto_alloc_size = sizeof(struct gpio_dev_priv), +}; |