diff options
| -rw-r--r-- | include/tinyalsa/mixer.h | 28 | ||||
| -rw-r--r-- | src/mixer.c | 46 |
2 files changed, 46 insertions, 28 deletions
diff --git a/include/tinyalsa/mixer.h b/include/tinyalsa/mixer.h index 4de6133..a54b5c1 100644 --- a/include/tinyalsa/mixer.h +++ b/include/tinyalsa/mixer.h @@ -69,9 +69,11 @@ struct mixer *mixer_open(unsigned int card); void mixer_close(struct mixer *mixer); -const char *mixer_get_name(struct mixer *mixer); +const char *mixer_get_name(const struct mixer *mixer); -unsigned int mixer_get_num_ctls(struct mixer *mixer); +unsigned int mixer_get_num_ctls(const struct mixer *mixer); + +const struct mixer_ctl *mixer_get_ctl_const(const struct mixer *mixer, unsigned int id); struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id); @@ -81,17 +83,17 @@ struct mixer_ctl *mixer_get_ctl_by_name_and_index(struct mixer *mixer, const char *name, unsigned int index); -unsigned int mixer_ctl_get_id(struct mixer_ctl *ctl); +unsigned int mixer_ctl_get_id(const struct mixer_ctl *ctl); -const char *mixer_ctl_get_name(struct mixer_ctl *ctl); +const char *mixer_ctl_get_name(const struct mixer_ctl *ctl); -enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl); +enum mixer_ctl_type mixer_ctl_get_type(const struct mixer_ctl *ctl); -const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl); +const char *mixer_ctl_get_type_string(const struct mixer_ctl *ctl); -unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl); +unsigned int mixer_ctl_get_num_values(const struct mixer_ctl *ctl); -unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl); +unsigned int mixer_ctl_get_num_enums(const struct mixer_ctl *ctl); const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, unsigned int enum_id); @@ -102,13 +104,13 @@ const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, unsigned int enum_i void mixer_ctl_update(struct mixer_ctl *ctl); /* Set and get mixer controls */ -int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id); +int mixer_ctl_get_percent(const struct mixer_ctl *ctl, unsigned int id); int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent); -int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id); +int mixer_ctl_get_value(const struct mixer_ctl *ctl, unsigned int id); -int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count); +int mixer_ctl_get_array(const struct mixer_ctl *ctl, void *array, size_t count); int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value); @@ -117,9 +119,9 @@ int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count); int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string); /* Determe range of integer mixer controls */ -int mixer_ctl_get_range_min(struct mixer_ctl *ctl); +int mixer_ctl_get_range_min(const struct mixer_ctl *ctl); -int mixer_ctl_get_range_max(struct mixer_ctl *ctl); +int mixer_ctl_get_range_max(const struct mixer_ctl *ctl); #if defined(__cplusplus) } /* extern "C" */ diff --git a/src/mixer.c b/src/mixer.c index 0fe9c99..4bb1756 100644 --- a/src/mixer.c +++ b/src/mixer.c @@ -176,7 +176,7 @@ fail: * @returns The name of the mixer's card. * @ingroup libtinyalsa-mixer */ -const char *mixer_get_name(struct mixer *mixer) +const char *mixer_get_name(const struct mixer *mixer) { return (const char *)mixer->card_info.name; } @@ -186,7 +186,7 @@ const char *mixer_get_name(struct mixer *mixer) * @returns The number of mixer controls for the given mixer. * @ingroup libtinyalsa-mixer */ -unsigned int mixer_get_num_ctls(struct mixer *mixer) +unsigned int mixer_get_num_ctls(const struct mixer *mixer) { if (!mixer) return 0; @@ -195,6 +195,22 @@ unsigned int mixer_get_num_ctls(struct mixer *mixer) } /** Gets a mixer control handle, by the mixer control's id. + * For non-const access, see @ref mixer_get_ctl + * @param mixer An initialized mixer handle. + * @param id The control's id in the given mixer. + * @returns A handle to the mixer control. + * @ingroup libtinyalsa-mixer + */ +const struct mixer_ctl *mixer_get_ctl_const(const struct mixer *mixer, unsigned int id) +{ + if (mixer && (id < mixer->count)) + return mixer->ctl + id; + + return NULL; +} + +/** Gets a mixer control handle, by the mixer control's id. + * For const access, see @ref mixer_get_ctl_const * @param mixer An initialized mixer handle. * @param id The control's id in the given mixer. * @returns A handle to the mixer control. @@ -263,7 +279,7 @@ void mixer_ctl_update(struct mixer_ctl *ctl) * On error, UINT_MAX is returned instead. * @ingroup libtinyalsa-mixer */ -unsigned int mixer_ctl_get_id(struct mixer_ctl *ctl) +unsigned int mixer_ctl_get_id(const struct mixer_ctl *ctl) { if (!ctl) return UINT_MAX; @@ -280,7 +296,7 @@ unsigned int mixer_ctl_get_id(struct mixer_ctl *ctl) * On error, NULL. * @ingroup libtinyalsa-mixer */ -const char *mixer_ctl_get_name(struct mixer_ctl *ctl) +const char *mixer_ctl_get_name(const struct mixer_ctl *ctl) { if (!ctl) return NULL; @@ -294,7 +310,7 @@ const char *mixer_ctl_get_name(struct mixer_ctl *ctl) * On failure, it returns @ref MIXER_CTL_TYPE_UNKNOWN * @ingroup libtinyalsa-mixer */ -enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl) +enum mixer_ctl_type mixer_ctl_get_type(const struct mixer_ctl *ctl) { if (!ctl) return MIXER_CTL_TYPE_UNKNOWN; @@ -315,7 +331,7 @@ enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl) * @returns On success, a string describing type of mixer control. * @ingroup libtinyalsa-mixer */ -const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl) +const char *mixer_ctl_get_type_string(const struct mixer_ctl *ctl) { if (!ctl) return ""; @@ -336,7 +352,7 @@ const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl) * @returns The number of values in the mixer control * @ingroup libtinyalsa-mixer */ -unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl) +unsigned int mixer_ctl_get_num_values(const struct mixer_ctl *ctl) { if (!ctl) return 0; @@ -344,7 +360,7 @@ unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl) return ctl->info.count; } -static int percent_to_int(struct snd_ctl_elem_info *ei, int percent) +static int percent_to_int(const struct snd_ctl_elem_info *ei, int percent) { if ((percent > 100) || (percent < 0)) { return -EINVAL; @@ -355,7 +371,7 @@ static int percent_to_int(struct snd_ctl_elem_info *ei, int percent) return ei->value.integer.min + (range * percent) / 100; } -static int int_to_percent(struct snd_ctl_elem_info *ei, int value) +static int int_to_percent(const struct snd_ctl_elem_info *ei, int value) { int range = (ei->value.integer.max - ei->value.integer.min); @@ -372,7 +388,7 @@ static int int_to_percent(struct snd_ctl_elem_info *ei, int value) * On failure, -EINVAL is returned. * @ingroup libtinyalsa-mixer */ -int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id) +int mixer_ctl_get_percent(const struct mixer_ctl *ctl, unsigned int id) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) return -EINVAL; @@ -403,7 +419,7 @@ int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent) * On failure, -EINVAL is returned. * @ingroup libtinyalsa-mixer */ -int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id) +int mixer_ctl_get_value(const struct mixer_ctl *ctl, unsigned int id) { struct snd_ctl_elem_value ev; int ret; @@ -449,7 +465,7 @@ int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id) * On failure, non-zero. * @ingroup libtinyalsa-mixer */ -int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count) +int mixer_ctl_get_array(const struct mixer_ctl *ctl, void *array, size_t count) { struct snd_ctl_elem_value ev; int ret = 0; @@ -634,7 +650,7 @@ int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count) * On failure, -EINVAL. * @ingroup libtinyalsa-mixer */ -int mixer_ctl_get_range_min(struct mixer_ctl *ctl) +int mixer_ctl_get_range_min(const struct mixer_ctl *ctl) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) return -EINVAL; @@ -650,7 +666,7 @@ int mixer_ctl_get_range_min(struct mixer_ctl *ctl) * On failure, -EINVAL. * @ingroup libtinyalsa-mixer */ -int mixer_ctl_get_range_max(struct mixer_ctl *ctl) +int mixer_ctl_get_range_max(const struct mixer_ctl *ctl) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) return -EINVAL; @@ -663,7 +679,7 @@ int mixer_ctl_get_range_max(struct mixer_ctl *ctl) * @returns The number of enumerated items in the control. * @ingroup libtinyalsa-mixer */ -unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl) +unsigned int mixer_ctl_get_num_enums(const struct mixer_ctl *ctl) { if (!ctl) return 0; |