mixer: make error handling more consistent
Remove the use of the errno variable and instead return errors
directly where appropriate.
diff --git a/mixer.c b/mixer.c
index 0c2e233..5563bc6 100644
--- a/mixer.c
+++ b/mixer.c
@@ -59,10 +59,8 @@
{
unsigned int n,m;
- if (!mixer) {
- errno = EINVAL;
+ if (!mixer)
return;
- }
if (mixer->fd >= 0)
close(mixer->fd);
@@ -167,10 +165,8 @@
unsigned int mixer_get_num_ctls(struct mixer *mixer)
{
- if (!mixer) {
- errno = EINVAL;
+ if (!mixer)
return 0;
- }
return mixer->count;
}
@@ -180,7 +176,6 @@
if (mixer && (id < mixer->count))
return mixer->ctl + id;
- errno = EINVAL;
return NULL;
}
@@ -189,23 +184,19 @@
unsigned int n;
if (!mixer)
- goto error;
+ return NULL;
for (n = 0; n < mixer->count; n++)
if (!strcmp(name, (char*) mixer->info[n].id.name))
return mixer->ctl + n;
-error:
- errno = EINVAL;
return NULL;
}
int mixer_ctl_get_name(struct mixer_ctl *ctl, char *name, unsigned int size)
{
- if (!ctl || !name || (size == 0)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || !name || (size == 0))
+ return -EINVAL;
strncpy(name, (char *)ctl->info->id.name, size);
return 0;
@@ -213,10 +204,8 @@
enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl)
{
- if (!ctl) {
- errno = EINVAL;
+ if (!ctl)
return MIXER_CTL_TYPE_UNKNOWN;
- }
switch (ctl->info->type) {
case SNDRV_CTL_ELEM_TYPE_BOOLEAN: return MIXER_CTL_TYPE_BOOL;
@@ -231,10 +220,8 @@
const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl)
{
- if (!ctl) {
- errno = EINVAL;
+ if (!ctl)
return "";
- }
switch (ctl->info->type) {
case SNDRV_CTL_ELEM_TYPE_BOOLEAN: return "BOOL";
@@ -249,10 +236,8 @@
unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl)
{
- if (!ctl) {
- errno = EINVAL;
+ if (!ctl)
return 0;
- }
return ctl->info->count;
}
@@ -283,20 +268,16 @@
int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id)
{
- if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER))
+ return -EINVAL;
return int_to_percent(ctl->info, mixer_ctl_get_value(ctl, id));
}
int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent)
{
- if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER))
+ return -EINVAL;
return mixer_ctl_set_value(ctl, id, percent_to_int(ctl->info, percent));
}
@@ -304,16 +285,16 @@
int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id)
{
struct snd_ctl_elem_value ev;
+ int ret;
- if (!ctl || (id >= ctl->info->count)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (id >= ctl->info->count))
+ return -EINVAL;
memset(&ev, 0, sizeof(ev));
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev);
+ if (ret < 0)
+ return ret;
switch (ctl->info->type) {
case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
@@ -326,8 +307,7 @@
return ev.value.enumerated.item[id];
default:
- errno = EINVAL;
- return -1;
+ return -EINVAL;
}
return 0;
@@ -336,16 +316,16 @@
int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value)
{
struct snd_ctl_elem_value ev;
+ int ret;
- if (!ctl || (id >= ctl->info->count)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (id >= ctl->info->count))
+ return -EINVAL;
memset(&ev, 0, sizeof(ev));
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev);
+ if (ret < 0)
+ return ret;
switch (ctl->info->type) {
case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
@@ -361,8 +341,7 @@
break;
default:
- errno = EINVAL;
- return -1;
+ return -EINVAL;
}
return ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev);
@@ -371,16 +350,16 @@
int mixer_ctl_get_range_min(struct mixer_ctl *ctl)
{
struct snd_ctl_elem_value ev;
+ int ret;
- if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER))
+ return -EINVAL;
memset(&ev, 0, sizeof(ev));
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev);
+ if (ret < 0)
+ return ret;
return ctl->info->value.integer.min;
}
@@ -388,26 +367,24 @@
int mixer_ctl_get_range_max(struct mixer_ctl *ctl)
{
struct snd_ctl_elem_value ev;
+ int ret;
- if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_INTEGER))
+ return -EINVAL;
memset(&ev, 0, sizeof(ev));
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev);
+ if (ret < 0)
+ return ret;
return ctl->info->value.integer.max;
}
unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl)
{
- if (!ctl) {
- errno = EINVAL;
+ if (!ctl)
return 0;
- }
return ctl->info->value.enumerated.items;
}
@@ -416,17 +393,17 @@
char *string, unsigned int size)
{
struct snd_ctl_elem_value ev;
+ int ret;
if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_ENUMERATED) ||
- (enum_id >= ctl->info->value.enumerated.items)) {
- errno = EINVAL;
- return -1;
- }
+ (enum_id >= ctl->info->value.enumerated.items))
+ return -EINVAL;
memset(&ev, 0, sizeof(ev));
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev))
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_READ, &ev);
+ if (ret < 0)
+ return ret;
strncpy(string, (char *)ctl->ename[enum_id], size);
return 0;
@@ -436,11 +413,10 @@
{
unsigned int i, num_enums;
struct snd_ctl_elem_value ev;
+ int ret;
- if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_ENUMERATED)) {
- errno = EINVAL;
- return -1;
- }
+ if (!ctl || (ctl->info->type != SNDRV_CTL_ELEM_TYPE_ENUMERATED))
+ return -EINVAL;
num_enums = ctl->info->value.enumerated.items;
for (i = 0; i < num_enums; i++) {
@@ -448,13 +424,13 @@
memset(&ev, 0, sizeof(ev));
ev.value.enumerated.item[0] = i;
ev.id.numid = ctl->info->id.numid;
- if (ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev) < 0)
- return -1;
+ ret = ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev);
+ if (ret < 0)
+ return ret;
return 0;
}
}
- errno = EINVAL;
- return -1;
+ return -EINVAL;
}