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