Angel Pons | 32859fc | 2020-04-02 23:48:27 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
David Hendricks | f4c3508 | 2012-12-27 14:15:51 -0800 | [diff] [blame] | 2 | |
David Hendricks | cfb7360 | 2013-04-05 13:42:39 -0700 | [diff] [blame] | 3 | #ifndef _DEVICE_I2C_H_ |
| 4 | #define _DEVICE_I2C_H_ |
David Hendricks | f4c3508 | 2012-12-27 14:15:51 -0800 | [diff] [blame] | 5 | |
Gabe Black | a5dc091 | 2013-06-30 03:47:33 -0700 | [diff] [blame] | 6 | #include <stdint.h> |
| 7 | |
Nico Huber | 029dfff | 2017-07-12 17:59:16 +0200 | [diff] [blame] | 8 | /** |
| 9 | * struct i2c_msg - an I2C transaction segment beginning with START |
| 10 | * @addr: Slave address, either seven or ten bits. When this is a ten |
| 11 | * bit address, I2C_M_TEN must be set in @flags. |
| 12 | * @flags: I2C_M_RD is handled by all adapters. |
| 13 | * @len: Number of data bytes in @buf being read from or written to the |
| 14 | * I2C slave address. For read transactions where I2C_M_RECV_LEN |
| 15 | * is set, the caller guarantees that this buffer can hold up to |
| 16 | * 32 bytes in addition to the initial length byte sent by the |
| 17 | * slave (plus, if used, the SMBus PEC). |
| 18 | * @buf: The buffer into which data is read, or from which it's written. |
| 19 | * |
| 20 | * An i2c_msg is the low level representation of one segment of an I2C |
| 21 | * transaction. It is visible to drivers in the @i2c_transfer() procedure. |
| 22 | * |
| 23 | * All I2C adapters implement the standard rules for I2C transactions. Each |
| 24 | * transaction begins with a START. That is followed by the slave address, |
| 25 | * and a bit encoding read versus write. Then follow all the data bytes, |
| 26 | * possibly including a byte with SMBus PEC. The transfer terminates with |
| 27 | * a NAK, or when all those bytes have been transferred and ACKed. If this |
| 28 | * is the last message in a group, it is followed by a STOP. Otherwise it |
| 29 | * is followed by the next @i2c_msg transaction segment, beginning with a |
| 30 | * (repeated) START. |
| 31 | */ |
| 32 | struct i2c_msg { |
| 33 | uint16_t flags; |
| 34 | #define I2C_M_RD 0x0001 /* read data, from slave to master */ |
| 35 | #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ |
| 36 | #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ |
| 37 | #define I2C_M_NOSTART 0x4000 /* don't send a repeated START */ |
| 38 | uint16_t slave; /* slave address */ |
| 39 | uint16_t len; /* msg length */ |
| 40 | uint8_t *buf; /* pointer to msg data */ |
| 41 | }; |
| 42 | |
Duncan Laurie | 1010b4a | 2016-05-09 20:10:47 -0700 | [diff] [blame] | 43 | enum i2c_speed { |
| 44 | I2C_SPEED_STANDARD = 100000, |
| 45 | I2C_SPEED_FAST = 400000, |
| 46 | I2C_SPEED_FAST_PLUS = 1000000, |
| 47 | I2C_SPEED_HIGH = 3400000, |
| 48 | I2C_SPEED_FAST_ULTRA = 5000000, |
| 49 | }; |
| 50 | |
| 51 | enum i2c_address_mode { |
| 52 | I2C_MODE_7_BIT, |
| 53 | I2C_MODE_10_BIT |
| 54 | }; |
| 55 | |
David Hendricks | cfb7360 | 2013-04-05 13:42:39 -0700 | [diff] [blame] | 56 | #endif /* _DEVICE_I2C_H_ */ |