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| author | Marti Bolivar <mbolivar@leaflabs.com> | 2012-06-20 16:34:15 -0400 |
|---|---|---|
| committer | Marti Bolivar <mbolivar@leaflabs.com> | 2012-06-22 14:06:10 -0400 |
| commit | a3344f4ab3ab90b1aec05c97cb026cec9ec73e9e (patch) | |
| tree | af01e37230f66713d00c8a7ef0c779d032a8cab9 | |
| parent | 0262fe55fa5c87264b3e93358474a77289603d20 (diff) | |
| download | librambutan-a3344f4ab3ab90b1aec05c97cb026cec9ec73e9e.tar.gz librambutan-a3344f4ab3ab90b1aec05c97cb026cec9ec73e9e.zip | |
libmaple/i2c.h: Better comments.
Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>
| -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 |