diff options
Diffstat (limited to 'include/sbi_utils')
-rw-r--r-- | include/sbi_utils/gpio/gpio.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/include/sbi_utils/gpio/gpio.h b/include/sbi_utils/gpio/gpio.h new file mode 100644 index 0000000..167d11a --- /dev/null +++ b/include/sbi_utils/gpio/gpio.h @@ -0,0 +1,99 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * + * Authors: + * Anup Patel <anup.patel@wdc.com> + */ + +#ifndef __GPIO_H__ +#define __GPIO_H__ + +#include <sbi/sbi_types.h> + +#define GPIO_LINE_DIRECTION_IN 1 +#define GPIO_LINE_DIRECTION_OUT 0 + +/** Representation of a GPIO pin */ +struct gpio_pin { + /** Pointer to the GPIO chip */ + struct gpio_chip *chip; + /** Identification of GPIO pin within GPIO chip */ + unsigned int offset; + /** + * Additional configuration flags of the GPIO pin desired + * by GPIO clients. + * + * NOTE: GPIO chip can have custom configuration flags. + */ + unsigned int flags; +#define GPIO_FLAG_ACTIVE_LOW 0x1 +#define GPIO_FLAG_SINGLE_ENDED 0x2 +#define GPIO_FLAG_OPEN_DRAIN 0x4 +#define GPIO_FLAG_TRANSITORY 0x8 +#define GPIO_FLAG_PULL_UP 0x10 +#define GPIO_FLAG_PULL_DOWN 0x20 +}; + +/** Representation of a GPIO chip */ +struct gpio_chip { + /** Pointer to GPIO driver owning this GPIO chip */ + void *driver; + /** Uniquie ID of the GPIO chip assigned by the driver */ + unsigned int id; + /** Number of GPIOs supported by the GPIO chip */ + unsigned int ngpio; + /** + * Get current direction of GPIO pin + * + * @return 0=output, 1=input, or negative error + */ + int (*get_direction)(struct gpio_pin *gp); + /** + * Set input direction of GPIO pin + * + * @return 0 on success and negative error code on failure + */ + int (*direction_input)(struct gpio_pin *gp); + /** + * Set output direction of GPIO pin with given output value + * + * @return 0 on success and negative error code on failure + */ + int (*direction_output)(struct gpio_pin *gp, int value); + /** + * Get current value of GPIO pin + * + * @return 0=low, 1=high, or negative error + */ + int (*get)(struct gpio_pin *gp); + /** Set output value for GPIO pin */ + void (*set)(struct gpio_pin *gp, int value); +}; + +/** Find a registered GPIO chip */ +struct gpio_chip *gpio_chip_find(unsigned int id); + +/** Register GPIO chip */ +int gpio_chip_add(struct gpio_chip *gc); + +/** Un-register GPIO chip */ +void gpio_chip_remove(struct gpio_chip *gc); + +/** Get current direction of GPIO pin */ +int gpio_get_direction(struct gpio_pin *gp); + +/** Set input direction of GPIO pin */ +int gpio_direction_input(struct gpio_pin *gp); + +/** Set output direction of GPIO pin */ +int gpio_direction_output(struct gpio_pin *gp, int value); + +/** Get current value of GPIO pin */ +int gpio_get(struct gpio_pin *gp); + +/** Set output value of GPIO pin */ +int gpio_set(struct gpio_pin *gp, int value); + +#endif |