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4a6bf832bc0367beb446fe70ebff7c65593415ea
mraa/src/i2c/i2c.c
Henry Bruce 4a6bf832bc usb: Converted sub-platform bus/pin helper macros to functions. 
Signed-off-by: Henry Bruce <henry.bruce@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
2015-09-08 14:42:03 +01:00

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9.6 KiB
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/*
* 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
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "i2c.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"
// FIXME: Nasty macro to test for presence of function in context structure function table
#define IS_FUNC_DEFINED(dev, func) (dev != NULL && dev->func_table != NULL && dev->func_table->func != NULL)
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;
static mraa_adv_func_t* func_table;
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)
{
mraa_board_t* board = plat;
if (board == NULL) {
syslog(LOG_ERR, "i2c: Platform Not Initialised");
return NULL;
}
if (mraa_is_on_sub_platform(bus)) {
syslog(LOG_NOTICE, "i2c: Using sub platform");
board = board->sub_platform;
if (board == NULL) {
syslog(LOG_ERR, "i2c: Sub platform Not Initialised");
return NULL;
}
bus = mraa_get_sub_platform_index(bus);
}
if (board->i2c_bus_count == 0) {
syslog(LOG_ERR, "No i2c buses defined in platform");
return NULL;
}
if (bus >= board->i2c_bus_count) {
syslog(LOG_ERR, "Above i2c bus count");
return NULL;
}
if (board->i2c_bus[bus].bus_id == -1) {
syslog(LOG_ERR, "Invalid i2c bus, moving to default i2c bus");
bus = board->def_i2c_bus;
}
int pos = board->i2c_bus[bus].sda;
if (board->pins[pos].i2c.mux_total > 0) {
if (mraa_setup_mux_mapped(board->pins[pos].i2c) != MRAA_SUCCESS) {
syslog(LOG_ERR, "i2c: Failed to set-up i2c sda multiplexer");
return NULL;
}
}
pos = board->i2c_bus[bus].scl;
if (board->pins[pos].i2c.mux_total > 0) {
if (mraa_setup_mux_mapped(board->pins[pos].i2c) != MRAA_SUCCESS) {
syslog(LOG_ERR, "i2c: Failed to set-up i2c scl multiplexer");
return NULL;
}
}
// FIXME: use global func_table variable to access advanced function table without changing i2c_init_raw() signature
func_table = board->adv_func;
return mraa_i2c_init_raw((unsigned int) board->i2c_bus[bus].bus_id);
}
mraa_i2c_context
mraa_i2c_init_raw(unsigned int bus)
{
mraa_i2c_context dev = (mraa_i2c_context) malloc(sizeof(struct _i2c));
if (dev == NULL) {
syslog(LOG_CRIT, "i2c: Failed to allocate memory for context");
return NULL;
}
dev->func_table = func_table;
dev->busnum = bus;
if (IS_FUNC_DEFINED(dev, i2c_init_pre)) {
if (func_table->i2c_init_pre(bus) != MRAA_SUCCESS)
return NULL;
}
if (!IS_FUNC_DEFINED(dev, i2c_init_bus_replace)) {
char filepath[32];
snprintf(filepath, 32, "/dev/i2c-%u", bus);
if ((dev->fh = open(filepath, O_RDWR)) < 1) {
syslog(LOG_ERR, "i2c: Failed to open requested i2c port %s", filepath);
}
syslog(LOG_DEBUG, "i2c: Opened i2c bus %s", filepath);
if (ioctl(dev->fh, I2C_FUNCS, &dev->funcs) < 0) {
syslog(LOG_CRIT, "i2c: Failed to get I2C_FUNC map from device");
dev->funcs = 0;
}
} else {
if (dev->func_table->i2c_init_bus_replace(dev) != MRAA_SUCCESS) {
free(dev);
return NULL;
}
}
if (IS_FUNC_DEFINED(dev, i2c_init_post)) {
mraa_result_t ret = dev->func_table->i2c_init_post(dev);
if (ret != MRAA_SUCCESS) {
free(dev);
return NULL;
}
}
return dev;
}
mraa_result_t
mraa_i2c_frequency(mraa_i2c_context dev, mraa_i2c_mode_t mode)
{
if (IS_FUNC_DEFINED(dev, i2c_set_frequency_replace)) {
return dev->func_table->i2c_set_frequency_replace(dev, mode);
}
return MRAA_ERROR_FEATURE_NOT_SUPPORTED;
}
int
mraa_i2c_read(mraa_i2c_context dev, uint8_t* data, int length)
{
int bytes_read = 0;
if (!IS_FUNC_DEFINED(dev, i2c_read_replace)) {
// this is the read(3) syscall not mraa_i2c_read()
bytes_read = read(dev->fh, data, length);
} else
bytes_read = dev->func_table->i2c_read_replace(dev, data, length);
if (bytes_read == length)
return length;
else
return 0;
}
uint8_t
mraa_i2c_read_byte(mraa_i2c_context dev)
{
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)
{
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)
{
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.word;
}
int
mraa_i2c_read_bytes_data(mraa_i2c_context dev, uint8_t command, uint8_t* data, int length)
{
struct i2c_rdwr_ioctl_data d;
struct i2c_msg m[2];
m[0].addr = dev->addr;
m[0].flags = 0x00;
m[0].len = 1;
m[0].buf = &command;
m[1].addr = dev->addr;
m[1].flags = I2C_M_RD;
m[1].len = length;
m[1].buf = data;
d.msgs = m;
d.nmsgs = 2;
return ioctl(dev->fh, I2C_RDWR, &d) < 0 ? -1 : length;
}
mraa_result_t
mraa_i2c_write(mraa_i2c_context dev, const uint8_t* data, int length)
{
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;
}
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 (!IS_FUNC_DEFINED(dev, i2c_write_byte_replace)) {
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;
}
return MRAA_SUCCESS;
} else
return dev->func_table->i2c_write_byte_replace(dev, data);
}
mraa_result_t
mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t command)
{
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;
}
return MRAA_SUCCESS;
}
mraa_result_t
mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data, const uint8_t command)
{
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;
}
return MRAA_SUCCESS;
}
mraa_result_t
mraa_i2c_address(mraa_i2c_context dev, uint8_t addr)
{
dev->addr = (int) addr;
if (dev->func_table->i2c_init_bus_replace == NULL) {
if (ioctl(dev->fh, I2C_SLAVE_FORCE, addr) < 0) {
syslog(LOG_ERR, "i2c: Failed to set slave address %d", addr);
return MRAA_ERROR_INVALID_HANDLE;
}
return MRAA_SUCCESS;
} else
return dev->func_table->i2c_address_replace(dev, addr);
}
mraa_result_t
mraa_i2c_stop(mraa_i2c_context dev)
{
free(dev);
return MRAA_SUCCESS;
}
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