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i2c: remove smbus helper library & clean up command use in API

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This commit changes the mraa_i2c_read() API call behaviour, a register should
now always be set when using this call. The smbus helper library is no longer
required since the code is now all contained from i2c.c which avoids multiple
function calls

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Brendan Le Foll
2014-11-18 16:09:08 +00:00
parent e9de25d797
commit 19d7dad364
8 changed files with 146 additions and 546 deletions
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112
src/i2c/i2c.c
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@@ -2,6 +2,9 @@
* Author: Brendan Le Foll <brendan.le.foll@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* Code is modified from the RoadNarrows-robotics i2c library (distributed under
* the MIT license, license is included verbatim under src/i2c/LICENSE)
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
@@ -23,9 +26,47 @@
*/
#include "i2c.h"
#include "smbus.h"
#include "mraa_internal.h"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include "linux/i2c-dev.h"
typedef union i2c_smbus_data_union
{
uint8_t byte; ///< data byte
unsigned short word; ///< data short word
uint8_t block[I2C_SMBUS_BLOCK_MAX + 2];
///< block[0] is used for length and one more for PEC
} i2c_smbus_data_t;
typedef struct i2c_smbus_ioctl_data_struct
{
uint8_t read_write; ///< operation direction
uint8_t command; ///< ioctl command
int size; ///< data size
i2c_smbus_data_t *data; ///< data
} i2c_smbus_ioctl_data_t;
int
mraa_i2c_smbus_access(int fh, uint8_t read_write, uint8_t command, int size,
i2c_smbus_data_t *data)
{
i2c_smbus_ioctl_data_t args;
args.read_write = read_write;
args.command = command;
args.size = size;
args.data = data;
return ioctl(fh, I2C_SMBUS, &args);
}
mraa_i2c_context
mraa_i2c_init(int bus)
{
@@ -114,36 +155,69 @@ mraa_i2c_read(mraa_i2c_context dev, uint8_t* data, int length)
uint8_t
mraa_i2c_read_byte(mraa_i2c_context dev)
{
uint8_t byte = i2c_smbus_read_byte(dev->fh);
return byte;
i2c_smbus_data_t d;
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, I2C_NOCMD,
I2C_SMBUS_BYTE, &d) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return 0;
}
return 0x0FF & d.byte;
}
uint8_t
mraa_i2c_read_byte_data(mraa_i2c_context dev, uint8_t command)
{
return (uint8_t) i2c_smbus_read_byte_data(dev->fh, command);
i2c_smbus_data_t d;
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command,
I2C_SMBUS_BYTE_DATA, &d) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return 0;
}
return 0x0FF & d.byte;
}
uint16_t
mraa_i2c_read_word_data(mraa_i2c_context dev, uint8_t command)
{
return (uint16_t) i2c_smbus_read_word_data(dev->fh, command);
i2c_smbus_data_t d;
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_READ, command,
I2C_SMBUS_WORD_DATA, &d) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return 0;
}
return 0xFFFF & d.byte;
}
mraa_result_t
mraa_i2c_write(mraa_i2c_context dev, const uint8_t* data, int length)
{
if (i2c_smbus_write_i2c_block_data(dev->fh, data[0], length-1, (uint8_t*) data+1) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return MRAA_ERROR_INVALID_HANDLE;
i2c_smbus_data_t d;
int i;
uint8_t command = data[0];
data = &data[1];
length = length-1;
if (length > I2C_SMBUS_I2C_BLOCK_MAX) {
length = I2C_SMBUS_I2C_BLOCK_MAX;
}
return MRAA_SUCCESS;
for (i=1; i<=length; i++) {
d.block[i] = data[i-1];
}
d.block[0] = length;
return mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command,
I2C_SMBUS_I2C_BLOCK_DATA, &d);
}
mraa_result_t
mraa_i2c_write_byte(mraa_i2c_context dev, const uint8_t data)
{
if (i2c_smbus_write_byte(dev->fh, data) < 0) {
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, data,
I2C_SMBUS_BYTE, NULL) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return MRAA_ERROR_INVALID_HANDLE;
}
@@ -151,9 +225,14 @@ mraa_i2c_write_byte(mraa_i2c_context dev, const uint8_t data)
}
mraa_result_t
mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t command)
mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data,
const uint8_t command)
{
if (i2c_smbus_write_byte_data(dev->fh, command, data) < 0) {
i2c_smbus_data_t d;
d.byte = data;
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command,
I2C_SMBUS_BYTE_DATA, &d) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return MRAA_ERROR_INVALID_HANDLE;
}
@@ -161,9 +240,14 @@ mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t
}
mraa_result_t
mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data, const uint8_t command)
mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data,
const uint8_t command)
{
if (i2c_smbus_write_word_data(dev->fh, command, data) < 0) {
i2c_smbus_data_t d;
d.word = data;
if (mraa_i2c_smbus_access(dev->fh, I2C_SMBUS_WRITE, command,
I2C_SMBUS_WORD_DATA, &d) < 0) {
syslog(LOG_ERR, "i2c: Failed to write");
return MRAA_ERROR_INVALID_HANDLE;
}