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/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* I2C interface for Chrome EC */
#ifndef __CROS_EC_I2C_H
#define __CROS_EC_I2C_H
#include "common.h"
/* Flags for slave address field, in addition to the 8-bit address */
#define I2C_FLAG_BIG_ENDIAN 0x100 /* 16 byte values are MSB-first */
/* Data structure to define I2C port configuration. */
struct i2c_port_t {
const char *name; /* Port name */
int port; /* Port */
int kbps; /* Speed in kbps */
enum gpio_signal scl; /* Port SCL GPIO line */
enum gpio_signal sda; /* Port SDA GPIO line */
};
extern const struct i2c_port_t i2c_ports[];
extern const unsigned int i2c_ports_used;
/* Flags for i2c_xfer() */
#define I2C_XFER_START (1 << 0) /* Start smbus session from idle state */
#define I2C_XFER_STOP (1 << 1) /* Terminate smbus session with stop bit */
#define I2C_XFER_SINGLE (I2C_XFER_START | I2C_XFER_STOP) /* One transaction */
/**
* Transmit one block of raw data, then receive one block of raw data.
*
* This is a low-level platform-dependent function used by the other functions
* below. It must be called between i2c_lock(port, 1) and i2c_lock(port, 0).
*
* @param port Port to access
* @param slave_addr Slave device address
* @param out Data to send
* @param out_size Number of bytes to send
* @param in Destination buffer for received data
* @param in_size Number of bytes to receive
* @param flags Flags (see I2C_XFER_* above)
* @return EC_SUCCESS, or non-zero if error.
*/
int i2c_xfer(int port, int slave_addr, const uint8_t *out, int out_size,
uint8_t *in, int in_size, int flags);
#define I2C_LINE_SCL_HIGH (1 << 0)
#define I2C_LINE_SDA_HIGH (1 << 1)
#define I2C_LINE_IDLE (I2C_LINE_SCL_HIGH | I2C_LINE_SDA_HIGH)
/**
* Return raw I/O line levels (I2C_LINE_*) for a port when port is in alternate
* function mode.
*
* @param port Port to check
*/
int i2c_get_line_levels(int port);
/**
* Get GPIO pin for I2C SCL from the i2c port number
*
* @param port I2C port number
* @param sda Pointer to gpio signal to store the SCL gpio at
* @return EC_SUCCESS if a valid GPIO point is found, EC_ERROR_INVAL if not
*/
int get_scl_from_i2c_port(int port, enum gpio_signal *scl);
/**
* Get GPIO pin for I2C SDA from the i2c port number
*
* @param port I2C port number
* @param sda Pointer to gpio signal to store the SDA gpio at
* @return EC_SUCCESS if a valid GPIO point is found, EC_ERROR_INVAL if not
*/
int get_sda_from_i2c_port(int port, enum gpio_signal *sda);
/**
* Get the state of the SCL pin when port is not in alternate function mode.
*
* @param port I2C port of interest
* @return State of SCL pin
*/
int i2c_raw_get_scl(int port);
/**
* Get the state of the SDA pin when port is not in alternate function mode.
*
* @param port I2C port of interest
* @return State of SDA pin
*/
int i2c_raw_get_sda(int port);
/**
* Set the state of the SCL pin.
*
* @param port I2C port of interest
* @param level State to set SCL pin to
*/
void i2c_raw_set_scl(int port, int level);
/**
* Set the state of the SDA pin.
*
* @param port I2C port of interest
* @param level State to set SDA pin to
*/
void i2c_raw_set_sda(int port, int level);
/**
* Toggle the I2C pins into or out of raw / big-bang mode.
*
* @param port I2C port of interest
* @param enable Flag to enable raw mode or disable it
* @return EC_SUCCESS if successful
*/
int i2c_raw_mode(int port, int enable);
/**
* Lock / unlock an I2C port.
* @param port Port to lock
* @param lock 1 to lock, 0 to unlock
*/
void i2c_lock(int port, int lock);
/**
* Set the timeout for an I2C transaction.
*
* @param port Port to set timeout for
* @param timeout Timeout in usec, or 0 to use default
*/
void i2c_set_timeout(int port, uint32_t timeout);
/**
* Read a 16-bit register from the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space.
*/
int i2c_read16(int port, int slave_addr, int offset, int *data);
/**
* Write a 16-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space.
*/
int i2c_write16(int port, int slave_addr, int offset, int data);
/**
* Read an 8-bit register from the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space.
*/
int i2c_read8(int port, int slave_addr, int offset, int *data);
/**
* Write an 8-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space.
*/
int i2c_write8(int port, int slave_addr, int offset, int data);
/**
* @return non-zero if i2c bus is busy
*/
int i2c_is_busy(int port);
/**
* Attempt to unwedge an I2C bus.
*
* @param port I2C port
*
* @return EC_SUCCESS or EC_ERROR_UNKNOWN
*/
int i2c_unwedge(int port);
/**
* Read ascii string using smbus read block protocol.
* Read bytestream from <slaveaddr>:<offset> with format:
* [length_N] [byte_0] [byte_1] ... [byte_N-1]
*
* <len> : the max length of receving buffer. to read N bytes
* ascii, len should be at least N+1 to include the
* terminating 0.
* <len> == 0 : buffer size > 255
*/
int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
int len);
/**
* Convert port number to controller number, for multi-port controllers.
* This function will only be called if CONFIG_I2C_MULTI_PORT_CONTROLLER is
* defined.
*
* @parm port I2C port
*
* @return controller number, or -1 on invalid parameter
*/
int i2c_port_to_controller(int port);
#endif /* __CROS_EC_I2C_H */
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