/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef _DEVICE_I2C_H_ #define _DEVICE_I2C_H_ #include <stdint.h> /** * struct i2c_msg - an I2C transaction segment beginning with START * @addr: Slave address, either seven or ten bits. When this is a ten * bit address, I2C_M_TEN must be set in @flags. * @flags: I2C_M_RD is handled by all adapters. * @len: Number of data bytes in @buf being read from or written to the * I2C slave address. For read transactions where I2C_M_RECV_LEN * is set, the caller guarantees that this buffer can hold up to * 32 bytes in addition to the initial length byte sent by the * slave (plus, if used, the SMBus PEC). * @buf: The buffer into which data is read, or from which it's written. * * An i2c_msg is the low level representation of one segment of an I2C * transaction. It is visible to drivers in the @i2c_transfer() procedure. * * All I2C adapters implement the standard rules for I2C transactions. Each * transaction begins with a START. That is followed by the slave address, * and a bit encoding read versus write. Then follow all the data bytes, * possibly including a byte with SMBus PEC. The transfer terminates with * a NAK, or when all those bytes have been transferred and ACKed. If this * is the last message in a group, it is followed by a STOP. Otherwise it * is followed by the next @i2c_msg transaction segment, beginning with a * (repeated) START. */ struct i2c_msg { uint16_t flags; #define I2C_M_RD 0x0001 /* read data, from slave to master */ #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ #define I2C_M_NOSTART 0x4000 /* don't send a repeated START */ uint16_t slave; /* slave address */ uint16_t len; /* msg length */ uint8_t *buf; /* pointer to msg data */ }; enum i2c_speed { I2C_SPEED_STANDARD = 100000, I2C_SPEED_FAST = 400000, I2C_SPEED_FAST_PLUS = 1000000, I2C_SPEED_HIGH = 3400000, I2C_SPEED_FAST_ULTRA = 5000000, }; enum i2c_address_mode { I2C_MODE_7_BIT, I2C_MODE_10_BIT }; #endif /* _DEVICE_I2C_H_ */