DCMD_I2C

#include <hw/i2c.h>

#define DCMD_I2C_SEND               __DIOT (_DCMD_I2C, 5, i2c_send_t)

The arguments to devctl() are:

Argument	Value
`filedes`	A file descriptor that you obtained by opening the device.
`dcmd`	DCMD_I2C_SEND
`dev_data_ptr`	A pointer to a i2c_send_t that's followed by additional data
`n_bytes`	`sizeof(i2c_send_t)` plus the size of the additional data
`dev_info_ptr`	NULL

The DCMD_I2C_SEND command executes a master send transaction. It returns when the transaction is complete.

Input

i2c_send_t — the message header:

typedef struct {
    i2c_addr_t slave;  /* slave address */
    uint32_t   len;    /* length of send data in bytes */
    uint32_t   stop;   /* send stop when complete? (0=no, 1=yes) */
} i2c_send_t;

uint8_t[] — the data buffer

Output

None.

If an error occurs, the command returns:

EIO: The master send failed. The causes include: bad slave address, bad bus speed, bus is busy.
EFAULT: An error occurred while accessing the data buffer.
EINVAL: Bad message format.
ENOMEM: Insufficient memory.
EPERM: The master is locked by another connection.