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/**
* @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 */
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