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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
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60
src/gpio/gpio.c
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@@ -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;