1 files changed, 199 insertions, 0 deletions
diff --git a/src/include/ipxe/gpio.h b/src/include/ipxe/gpio.h
new file mode 100644
index 000000000..fa9e19089
--- /dev/null
+++ b/src/include/ipxe/gpio.h
@@ -0,0 +1,199 @@
+#ifndef _IPXE_GPIO_H
+#define _IPXE_GPIO_H
+
+/** @file
+ *
+ * General purpose I/O
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/list.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/device.h>
+
+/** A GPIO pin */
+struct gpio {
+	/** GPIO controller */
+	struct gpios *gpios;
+	/** Pin index */
+	unsigned int index;
+	/** Configuration */
+	unsigned int config;
+};
+
+/** GPIO is active low
+ *
+ * This bit is chosen to match the devicetree standard usage.
+ */
+#define GPIO_CFG_ACTIVE_LOW 0x01
+
+/** GPIO is an output */
+#define GPIO_CFG_OUTPUT 0x0100
+
+/** A GPIO controller */
+struct gpios {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** List of GPIO controllers */
+	struct list_head list;
+	/** Generic device */
+	struct device *dev;
+	/** Number of GPIOs */
+	unsigned int count;
+
+	/** Individual GPIOs */
+	struct gpio *gpio;
+	/** GPIO operations */
+	struct gpio_operations *op;
+
+	/** Driver-private data */
+	void *priv;
+};
+
+/** GPIO operations */
+struct gpio_operations {
+	/**
+	 * Get current GPIO input value
+	 *
+	 * @v gpios		GPIO controller
+	 * @v gpio		GPIO pin
+	 * @ret active		Pin is in the active state
+	 */
+	int ( * in ) ( struct gpios *gpios, struct gpio *gpio );
+	/**
+	 * Set current GPIO output value
+	 *
+	 * @v gpios		GPIO controller
+	 * @v gpio		GPIO pin
+	 * @v active		Set pin to active state
+	 */
+	void ( * out ) ( struct gpios *gpios, struct gpio *gpio, int active );
+	/**
+	 * Configure GPIO pin
+	 *
+	 * @v gpios		GPIO controller
+	 * @v gpio		GPIO pin
+	 * @v config		Configuration
+	 * @ret rc		Return status code
+	 */
+	int ( * config ) ( struct gpios *gpios, struct gpio *gpio,
+			   unsigned int config );
+};
+
+extern struct gpio_operations null_gpio_operations;
+
+/**
+ * Get reference to GPIO controller
+ *
+ * @v gpios		GPIO controller
+ * @ret gpios		GPIO controller
+ */
+static inline __attribute__ (( always_inline )) struct gpios *
+gpios_get ( struct gpios *gpios ) {
+	ref_get ( &gpios->refcnt );
+	return gpios;
+}
+
+/**
+ * Drop reference to GPIO controller
+ *
+ * @v gpios		GPIO controller
+ */
+static inline __attribute__ (( always_inline )) void
+gpios_put ( struct gpios *gpios ) {
+	ref_put ( &gpios->refcnt );
+}
+
+/**
+ * Get reference to GPIO pin
+ *
+ * @v gpio		GPIO pin
+ * @ret gpio		GPIO pin
+ */
+static inline __attribute__ (( always_inline )) struct gpio *
+gpio_get ( struct gpio *gpio ) {
+	gpios_get ( gpio->gpios );
+	return gpio;
+}
+
+/**
+ * Drop reference to GPIO ping
+ *
+ * @v gpio		GPIO pin
+ */
+static inline __attribute__ (( always_inline )) void
+gpio_put ( struct gpio *gpio ) {
+	gpios_put ( gpio->gpios );
+}
+
+/**
+ * Initialise a GPIO controller
+ *
+ * @v gpios		GPIO controller
+ * @v op		GPIO operations
+ */
+static inline __attribute__ (( always_inline )) void
+gpios_init ( struct gpios *gpios, struct gpio_operations *op ) {
+	gpios->op = op;
+}
+
+/**
+ * Stop using a GPIO controller
+ *
+ * @v gpios		GPIO controller
+ *
+ * Drivers should call this method immediately before the final call
+ * to gpios_put().
+ */
+static inline __attribute__ (( always_inline )) void
+gpios_nullify ( struct gpios *gpios ) {
+	gpios->op = &null_gpio_operations;
+}
+
+/**
+ * Get current GPIO input value
+ *
+ * @v gpio		GPIO pin
+ * @ret active		Pin is in the active state
+ */
+static inline int gpio_in ( struct gpio *gpio ) {
+	struct gpios *gpios = gpio->gpios;
+
+	return gpios->op->in ( gpios, gpio );
+}
+
+/**
+ * Set current GPIO output value
+ *
+ * @v gpio		GPIO pin
+ * @v active		Set pin to active state
+ */
+static inline void gpio_out ( struct gpio *gpio, int active ) {
+	struct gpios *gpios = gpio->gpios;
+
+	gpios->op->out ( gpios, gpio, active );
+}
+
+/**
+ * Configure GPIO pin
+ *
+ * @v gpio		GPIO pin
+ * @v config		Configuration
+ * @ret rc		Return status code
+ */
+static inline int gpio_config ( struct gpio *gpio, unsigned int config ) {
+	struct gpios *gpios = gpio->gpios;
+
+	return gpios->op->config ( gpios, gpio, config );
+}
+
+extern struct gpios * alloc_gpios ( unsigned int count, size_t priv_len );
+extern int gpios_register ( struct gpios *gpios );
+extern void gpios_unregister ( struct gpios *gpios );
+extern struct gpios * gpios_find ( unsigned int bus_type,
+				   unsigned int location );
+
+#endif /* _IPXE_GPIO_H */