diff options
Diffstat (limited to 'libmaple/include')
| -rw-r--r-- | libmaple/include/libmaple/i2c.h | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/libmaple/include/libmaple/i2c.h b/libmaple/include/libmaple/i2c.h index 8ea77d7..859edcd 100644 --- a/libmaple/include/libmaple/i2c.h +++ b/libmaple/include/libmaple/i2c.h @@ -28,6 +28,13 @@ /** * @file libmaple/include/libmaple/i2c.h * @brief Inter-Integrated Circuit (I2C) peripheral support + * + * Currently master-only. Usage notes: + * + * - Enable an I2C device with i2c_master_enable(). + * - Initialize an array of struct i2c_msg to suit the bus + * transactions (reads/writes) you wish to perform. + * - Call i2c_master_xfer() to do the work. */ #ifndef _LIBMAPLE_I2C_H_ @@ -72,10 +79,15 @@ typedef struct i2c_reg_map { */ typedef struct i2c_msg { uint16 addr; /**< Address */ + #define I2C_MSG_READ 0x1 #define I2C_MSG_10BIT_ADDR 0x2 - uint16 flags; /**< Bitwise OR of I2C_MSG_READ and - I2C_MSG_10BIT_ADDR */ + /** + * Bitwise OR of: + * - I2C_MSG_READ (write is default) + * - I2C_MSG_10BIT_ADDR (7-bit is default) */ + uint16 flags; + uint16 length; /**< Message length */ uint16 xferred; /**< Messages transferred */ uint8 *data; /**< Data */ @@ -165,6 +177,8 @@ typedef struct i2c_msg { * Convenience routines */ +/* Main I2C API */ + /* I2C enable options */ #define I2C_FAST_MODE 0x1 // 400 khz #define I2C_DUTY_16_9 0x2 // 16/9 duty ratio |