1 files changed, 95 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/raspberrypi/include/i2c.h b/c/src/lib/libbsp/arm/raspberrypi/include/i2c.h
new file mode 100644
index 0000000000..4a8dbbf2ac
--- /dev/null
+++ b/c/src/lib/libbsp/arm/raspberrypi/include/i2c.h
@@ -0,0 +1,95 @@
+/**
+ * @file i2c.h
+ *
+ * @ingroup raspberrypi_i2c
+ *
+ * @brief Raspberry Pi specific I2C definitions.
+ */
+
+/*
+ *  Copyright (c) 2014-2015 Andre Marques <andre.lousa.marques at gmail.com>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+
+#ifndef LIBBSP_ARM_RASPBERRYPI_I2C_H
+#define LIBBSP_ARM_RASPBERRYPI_I2C_H
+
+#include <dev/i2c/i2c.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @name I2C constants.
+ *
+ * @{
+ */
+
+/**
+ * @brief BSC controller core clock rate in Hz.
+ *
+ * This is set to 150 MHz as per the BCM2835 datasheet.
+ */
+#define BSC_CORE_CLK_HZ 150000000
+
+/**
+ * @brief Default bus clock.
+ *
+ * This sets the bus with a 100 kHz clock speed.
+ */
+#define DEFAULT_BUS_CLOCK 100000
+
+/** @} */
+
+/**
+ * @name  I2C directives.
+ *
+ * @{
+ */
+
+/**
+ * @brief Setups the Raspberry Pi GPIO header to activate the BSC I2C bus.
+ */
+extern void rpi_i2c_init(void);
+
+/**
+ * @brief Registers the Raspberry Pi BSC I2C bus with the
+ *        Linux I2C User-Space API.
+ *
+ * @param[in] bus_path Path to the bus device file.
+ * @param[in] bus_clock Bus clock in Hz.
+ *
+ * @retval 0 Bus registered successfully.
+ * @retval <0 Could not register the bus. The return value is a negative
+ *            errno code.
+ */
+extern int rpi_i2c_register_bus(
+  const char *bus_path,
+  uint32_t bus_clock
+);
+
+/**
+ * @brief Setups the Raspberry Pi BSC I2C bus (located on the GPIO header)
+ *        on the "/dev/i2c" device file, using the default bus clock.
+ *
+ * @retval 0 Bus configured and registered successfully.
+ * @retval <0 See @see rpi_i2c_register_bus().
+ */
+static inline int rpi_setup_i2c_bus(void)
+{
+  rpi_i2c_init();
+
+  return rpi_i2c_register_bus("/dev/i2c", DEFAULT_BUS_CLOCK);
+}
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* LIBBSP_ARM_RASPBERRYPI_I2C_H */