1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Helper functions for jack-detection kcontrols 4 * 5 * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/export.h> 10 #include <linux/string.h> 11 #include <sound/core.h> 12 #include <sound/control.h> 13 14 #define jack_detect_kctl_info snd_ctl_boolean_mono_info 15 16 static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol, 17 struct snd_ctl_elem_value *ucontrol) 18 { 19 ucontrol->value.integer.value[0] = kcontrol->private_value; 20 return 0; 21 } 22 23 static const struct snd_kcontrol_new jack_detect_kctl = { 24 /* name is filled later */ 25 .iface = SNDRV_CTL_ELEM_IFACE_CARD, 26 .access = SNDRV_CTL_ELEM_ACCESS_READ, 27 .info = jack_detect_kctl_info, 28 .get = jack_detect_kctl_get, 29 }; 30 31 static int get_available_index(struct snd_card *card, const char *name) 32 { 33 struct snd_ctl_elem_id sid; 34 35 memset(&sid, 0, sizeof(sid)); 36 37 sid.index = 0; 38 sid.iface = SNDRV_CTL_ELEM_IFACE_CARD; 39 strscpy(sid.name, name, sizeof(sid.name)); 40 41 while (snd_ctl_find_id(card, &sid)) { 42 sid.index++; 43 /* reset numid; otherwise snd_ctl_find_id() hits this again */ 44 sid.numid = 0; 45 } 46 47 return sid.index; 48 } 49 50 static void jack_kctl_name_gen(char *name, const char *src_name, size_t size) 51 { 52 size_t count = strlen(src_name); 53 const char *suf = " Jack"; 54 size_t suf_len = strlen(suf); 55 bool append_suf = true; 56 57 if (count >= suf_len) 58 append_suf = strncmp(&src_name[count - suf_len], suf, suf_len) != 0; 59 60 if (append_suf) 61 snprintf(name, size, "%s%s", src_name, suf); 62 else 63 strscpy(name, src_name, size); 64 } 65 66 struct snd_kcontrol * 67 snd_kctl_jack_new(const char *name, struct snd_card *card) 68 { 69 struct snd_kcontrol *kctl; 70 71 kctl = snd_ctl_new1(&jack_detect_kctl, NULL); 72 if (!kctl) 73 return NULL; 74 75 jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name)); 76 kctl->id.index = get_available_index(card, kctl->id.name); 77 kctl->private_value = 0; 78 return kctl; 79 } 80 81 void snd_kctl_jack_report(struct snd_card *card, 82 struct snd_kcontrol *kctl, bool status) 83 { 84 if (kctl->private_value == status) 85 return; 86 kctl->private_value = status; 87 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id); 88 } 89