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57aaa0267e
We only used I2C_PORTS_USED to iterate through the list of hardware ports actually in use, but we defined it in board.h at the same place where we matched particular I2C devices to the (possibly shared) buses they're on. This CL makes I2C_PORTS_USED into a global constant, so it can be set automatically where we initialize the ports, and doesn't have to be related to the list of attached devices. BUG=chrome-os-partner:18343 BRANCH=none TEST=manual Build everything, run all tests, should still work. Change-Id: I65f22f5cadfc4b3afe51af48faa5fb369bc3aa09 Signed-off-by: Bill Richardson <wfrichar@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/171884
96 lines
3.3 KiB
C
96 lines
3.3 KiB
C
/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* I2C interface for Chrome EC */
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#ifndef __CROS_EC_I2C_H
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#define __CROS_EC_I2C_H
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#include "common.h"
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/* Flags for slave address field, in addition to the 8-bit address */
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#define I2C_FLAG_BIG_ENDIAN 0x100 /* 16 byte values are MSB-first */
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/* Data structure to define I2C port configuration. */
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struct i2c_port_t {
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const char *name; /* Port name */
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int port; /* Port */
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int kbps; /* Speed in kbps */
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};
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extern const struct i2c_port_t i2c_ports[];
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extern const unsigned int i2c_ports_used;
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/* Flags for i2c_xfer() */
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#define I2C_XFER_START (1 << 0) /* Start smbus session from idle state */
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#define I2C_XFER_STOP (1 << 1) /* Terminate smbus session with stop bit */
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#define I2C_XFER_SINGLE (I2C_XFER_START | I2C_XFER_STOP) /* One transaction */
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/**
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* Transmit one block of raw data, then receive one block of raw data.
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*
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* This is a low-level platform-dependent function used by the other functions
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* below. It must be called between i2c_lock(port, 1) and i2c_lock(port, 0).
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*
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* @param port Port to access
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* @param slave_addr Slave device address
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* @param out Data to send
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* @param out_size Number of bytes to send
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* @param in Destination buffer for received data
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* @param in_size Number of bytes to receive
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* @param flags Flags (see I2C_XFER_* above)
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* @return EC_SUCCESS, or non-zero if error.
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*/
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int i2c_xfer(int port, int slave_addr, const uint8_t *out, int out_size,
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uint8_t *in, int in_size, int flags);
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#define I2C_LINE_SCL_HIGH (1 << 0)
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#define I2C_LINE_SDA_HIGH (1 << 1)
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#define I2C_LINE_IDLE (I2C_LINE_SCL_HIGH | I2C_LINE_SDA_HIGH)
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/**
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* Return raw I/O line levels (I2C_LINE_*) for a port.
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*
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* @param port Port to check
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*/
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int i2c_get_line_levels(int port);
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/**
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* Lock / unlock an I2C port.
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* @param port Port to lock
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* @param lock 1 to lock, 0 to unlock
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*/
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void i2c_lock(int port, int lock);
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/* Read a 16-bit register from the slave at 8-bit slave address <slaveaddr>, at
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* the specified 8-bit <offset> in the slave's address space. */
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int i2c_read16(int port, int slave_addr, int offset, int* data);
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/* Write a 16-bit register to the slave at 8-bit slave address <slaveaddr>, at
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* the specified 8-bit <offset> in the slave's address space. */
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int i2c_write16(int port, int slave_addr, int offset, int data);
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/* Read an 8-bit register from the slave at 8-bit slave address <slaveaddr>, at
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* the specified 8-bit <offset> in the slave's address space. */
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int i2c_read8(int port, int slave_addr, int offset, int* data);
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/* Write an 8-bit register to the slave at 8-bit slave address <slaveaddr>, at
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* the specified 8-bit <offset> in the slave's address space. */
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int i2c_write8(int port, int slave_addr, int offset, int data);
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/* Read ascii string using smbus read block protocol.
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* Read bytestream from <slaveaddr>:<offset> with format:
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* [length_N] [byte_0] [byte_1] ... [byte_N-1]
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*
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* <len> : the max length of receving buffer. to read N bytes
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* ascii, len should be at least N+1 to include the
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* terminating 0.
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* <len> == 0 : buffer size > 255
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*/
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int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
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int len);
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#endif /* __CROS_EC_I2C_H */
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