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gpio: rework of gpio - using open() for value_fp

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* fixes maa_gpio_read by using simple posix file io
* fixes blink sample to have much more error checking
* blink sample now takes an argument

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Brendan Le Foll
2014-05-13 15:35:27 +01:00
parent aa60cae49d
commit 126b1314b0
5 changed files with 150 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
api/gpio.h
View File

@@ -45,7 +45,7 @@ extern "C" {
typedef struct {
/*@{*/
int pin; /**< the pin number, as known to the os. */
FILE *value_fp; /**< the file pointer to the value of the gpio */
int value_fp; /**< the file pointer to the value of the gpio */
void (* isr)(); /**< the interupt service request */
pthread_t thread_id; /**< the isr handler thread id */
int isr_value_fp; /**< the isr file pointer on the value */

6
examples/CMakeLists.txt
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@@ -1,15 +1,17 @@
add_executable (i2c_HMC5883L i2c_HMC5883L.c)
add_executable (hellomaa hellomaa.c)
add_executable (cycle-pwm3 cycle-pwm3.c)
add_executable (blink-io8 blink-io8.c)
add_executable (blink-io blink-io.c)
add_executable (analogin_a0 analogin_a0.c)
add_executable (isr_pin6 isr_pin6.c)
add_executable (gpio_read6 gpio_read6.c)
include_directories(${PROJECT_SOURCE_DIR}/api ${PROJECT_SOURCE_DIR}/include)
target_link_libraries (hellomaa maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (i2c_HMC5883L maa m ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (cycle-pwm3 maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (blink-io8 maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (blink-io maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (analogin_a0 maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (isr_pin6 maa ${CMAKE_THREAD_LIBS_INIT})
target_link_libraries (gpio_read6 maa ${CMAKE_THREAD_LIBS_INIT})

100
examples/blink-io.c Normal file
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@@ -0,0 +1,100 @@
/*
* Author: Brendan Le Foll <brendan.le.foll@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* 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 <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include "gpio.h"
#define DEFAULT_IOPIN 8
int running = 0;
static int iopin;
void
sig_handler(int signo)
{
if (signo == SIGINT) {
printf("closing IO%d nicely\n", iopin);
running = -1;
}
}
int
main(int argc, char **argv)
{
maa_result_t r = MAA_SUCCESS;
iopin = DEFAULT_IOPIN;
if (argc < 2) {
printf("Provide an int arg if you want to flash on something other than %d\n", DEFAULT_IOPIN);
} else {
iopin = strtol(argv[1], NULL, 10);
}
maa_init();
fprintf(stdout, "MAA Version: %s\nStarting Blinking on IO%d\n",
maa_get_version(), iopin);
maa_gpio_context* gpio;
gpio = maa_gpio_init(iopin);
printf("Initialised pin%d which is atually pin%d\n", iopin, gpio->pin);
// set direction to OUT
r = maa_gpio_dir(gpio, MAA_GPIO_OUT);
if (r != MAA_SUCCESS) {
maa_result_print(r);
}
signal(SIGINT, sig_handler);
while (running == 0) {
r = maa_gpio_write(gpio, 0);
if (r != MAA_SUCCESS) {
maa_result_print(r);
} else {
printf("off\n");
}
sleep(1);
r = maa_gpio_write(gpio, 1);
if (r != MAA_SUCCESS) {
maa_result_print(r);
} else {
printf("on\n");
}
sleep(1);
}
r = maa_gpio_close(gpio);
if (r != MAA_SUCCESS) {
maa_result_print(r);
}
return r;
}

20
examples/blink-io8.c → examples/gpio_read6.c
View File

@@ -31,17 +31,21 @@ int
main(int argc, char **argv)
{
maa_init();
fprintf(stdout, "MAA Version: %s\nStarting Blinking on IO8\n",
fprintf(stdout, "MAA Version: %s\nStarting Read on IO6\n",
maa_get_version());
maa_gpio_context* gpio;
gpio = maa_gpio_init(8);
maa_gpio_dir(gpio, MAA_GPIO_OUT);
while (1) {
maa_gpio_write(gpio, 0);
sleep(1);
maa_gpio_write(gpio, 1);
maa_gpio_context* gpio;
gpio = maa_gpio_init(6);
maa_gpio_dir(gpio, MAA_GPIO_IN);
for (;;) {
fprintf(stdout, "Gpio is %d\n", maa_gpio_read(gpio));
sleep(1);
}
maa_gpio_close(gpio);
return 0;
}

60
src/gpio/gpio.c
View File

@@ -40,7 +40,8 @@ maa_gpio_get_valfp(maa_gpio_context *dev)
char bu[MAX_SIZE];
sprintf(bu, SYSFS_CLASS_GPIO "/gpio%d/value", dev->pin);
if ((dev->value_fp = fopen(bu, "r+b")) == NULL) {
dev->value_fp = open(bu, O_RDWR);
if (dev->value_fp == -1) {
return MAA_ERROR_INVALID_RESOURCE;
}
@@ -69,6 +70,7 @@ maa_gpio_init_raw(int pin)
maa_gpio_context* dev = (maa_gpio_context*) malloc(sizeof(maa_gpio_context));
memset(dev, 0, sizeof(maa_gpio_context));
dev->value_fp = -1;
dev->pin = pin;
if ((export_f = fopen(SYSFS_CLASS_GPIO "/export", "w")) == NULL) {
@@ -134,8 +136,9 @@ maa_gpio_interrupt_handler(void* arg)
maa_result_t
maa_gpio_edge_mode(maa_gpio_context *dev, gpio_edge_t mode)
{
if (dev->value_fp != NULL) {
dev->value_fp = NULL;
if (dev->value_fp != -1) {
close(dev->value_fp);
dev->value_fp = -1;
}
char filepath[MAX_SIZE];
@@ -169,7 +172,6 @@ maa_gpio_edge_mode(maa_gpio_context *dev, gpio_edge_t mode)
fwrite(bu, sizeof(char), length, edge);
fclose(edge);
dev->value_fp = NULL;
return MAA_SUCCESS;
}
@@ -210,8 +212,9 @@ maa_gpio_isr_exit(maa_gpio_context *dev)
maa_result_t
maa_gpio_mode(maa_gpio_context *dev, gpio_mode_t mode)
{
if (dev->value_fp != NULL) {
dev->value_fp = NULL;
if (dev->value_fp != -1) {
close(dev->value_fp);
dev->value_fp = -1;
}
char filepath[MAX_SIZE];
@@ -245,17 +248,18 @@ maa_gpio_mode(maa_gpio_context *dev, gpio_mode_t mode)
fwrite(bu, sizeof(char), length, drive);
fclose(drive);
dev->value_fp = NULL;
return MAA_SUCCESS;
}
maa_result_t
maa_gpio_dir(maa_gpio_context *dev, gpio_dir_t dir)
{
if (dev == NULL)
if (dev == NULL) {
return MAA_ERROR_INVALID_HANDLE;
if (dev->value_fp != NULL) {
dev->value_fp = NULL;
}
if (dev->value_fp != -1) {
close(dev->value_fp);
dev->value_fp = -1;
}
char filepath[MAX_SIZE];
snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/direction", dev->pin);
@@ -282,20 +286,26 @@ maa_gpio_dir(maa_gpio_context *dev, gpio_dir_t dir)
fwrite(bu, sizeof(char), length, direction);
fclose(direction);
dev->value_fp = NULL;
return MAA_SUCCESS;
}
int
maa_gpio_read(maa_gpio_context *dev)
{
if (dev->value_fp == NULL) {
maa_gpio_get_valfp(dev);
if (dev->value_fp == -1) {
if (maa_gpio_get_valfp(dev) != MAA_SUCCESS) {
fprintf(stderr, "Failed to get value file pointer\n");
}
}
else {
// if value_fp is new this is pointless
lseek(dev->value_fp, 0, SEEK_SET);
}
fseek(dev->value_fp, SEEK_SET, 0);
char bu[2];
fread(bu, 2, 1, dev->value_fp);
fseek(dev->value_fp, SEEK_SET, 0);
if (read(dev->value_fp, bu, 2*sizeof(char)) != 2) {
fprintf(stderr, "Failed to read a sensible value from sysfs");
}
lseek(dev->value_fp, 0, SEEK_SET);
int ret = strtol(bu, NULL, 10);
return ret;
@@ -304,22 +314,19 @@ maa_gpio_read(maa_gpio_context *dev)
maa_result_t
maa_gpio_write(maa_gpio_context *dev, int value)
{
if (dev->value_fp == NULL) {
if (dev->value_fp == -1) {
maa_gpio_get_valfp(dev);
}
if (fseek(dev->value_fp, SEEK_SET, 0) != 0) {
if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
return MAA_ERROR_INVALID_RESOURCE;
}
char bu[MAX_SIZE];
int length = snprintf(bu, sizeof(bu), "%d", value);
fwrite(bu, sizeof(char), length, dev->value_fp);
if (fseek(dev->value_fp, SEEK_SET, 0) != 0) {
return MAA_ERROR_INVALID_RESOURCE;
if (write(dev->value_fp, bu, length*sizeof(char)) == -1) {
return MAA_ERROR_INVALID_HANDLE;
}
if (ferror(dev->value_fp) != 0)
return MAA_ERROR_INVALID_RESOURCE;
return MAA_SUCCESS;
}
@@ -346,10 +353,9 @@ maa_gpio_unexport(maa_gpio_context *dev)
maa_result_t
maa_gpio_close(maa_gpio_context *dev)
{
if (ferror(dev->value_fp) != 0) {
return MAA_ERROR_INVALID_RESOURCE;
if (dev->value_fp != -1) {
close(dev->value_fp);
}
maa_gpio_unexport(dev);
free(dev);
return MAA_SUCCESS;