ALSA: usb-mixer: parse descriptors with structs

Introduce a number of new structs for mixer, selector, feature and
processing units and some static inline helpers to access fields which
have dynamic offsets. Use them in mixer.c to parse the descriptors. This
is necessary for the upcoming audio v2 parsers.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 47 insertions, 40 deletions

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 4e7c2fd9e3b..994b0385235 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -860,13 +860,14 @@ static size_t append_ctl_name(struct snd_kcontrol *kctl, const char *str)
         return strlcat(kctl->id.name, str, sizeof(kctl->id.name));
 }
 
-static void build_feature_ctl(struct mixer_build *state, unsigned char *desc,
+static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
                               unsigned int ctl_mask, int control,
                               struct usb_audio_term *iterm, int unitid)
 {
+        struct uac_feature_unit_descriptor *desc = raw_desc;
         unsigned int len = 0;
         int mapped_name = 0;
-        int nameid = desc[desc[0] - 1];
+        int nameid = uac_feature_unit_iFeature(desc);
         struct snd_kcontrol *kctl;
         struct usb_mixer_elem_info *cval;
         const struct usbmix_name_map *map;
@@ -1032,7 +1033,7 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 
         channels = (ftr->bLength - 7) / csize - 1;
 
-        master_bits = snd_usb_combine_bytes(ftr->controls, csize);
+        master_bits = snd_usb_combine_bytes(ftr->bmaControls, csize);
         /* master configuration quirks */
         switch (state->chip->usb_id) {
         case USB_ID(0x08bb, 0x2702):
@@ -1043,14 +1044,14 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
                 break;
         }
         if (channels > 0)
-                first_ch_bits = snd_usb_combine_bytes(ftr->controls + csize, csize);
+                first_ch_bits = snd_usb_combine_bytes(ftr->bmaControls + csize, csize);
         else
                 first_ch_bits = 0;
         /* check all control types */
         for (i = 0; i < 10; i++) {
                 unsigned int ch_bits = 0;
                 for (j = 0; j < channels; j++) {
-                        unsigned int mask = snd_usb_combine_bytes(ftr->controls + csize * (j+1), csize);
+                        unsigned int mask = snd_usb_combine_bytes(ftr->bmaControls + csize * (j+1), csize);
                         if (mask & (1 << i))
                                 ch_bits |= (1 << j);
                 }
@@ -1075,13 +1076,13 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
  * input channel number (zero based) is given in control field instead.
  */
 
-static void build_mixer_unit_ctl(struct mixer_build *state, unsigned char *desc,
+static void build_mixer_unit_ctl(struct mixer_build *state,
+                                 struct uac_mixer_unit_descriptor *desc,
                                  int in_pin, int in_ch, int unitid,
                                  struct usb_audio_term *iterm)
 {
         struct usb_mixer_elem_info *cval;
-        unsigned int input_pins = desc[4];
-        unsigned int num_outs = desc[5 + input_pins];
+        unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
         unsigned int i, len;
         struct snd_kcontrol *kctl;
         const struct usbmix_name_map *map;
@@ -1099,7 +1100,7 @@ static void build_mixer_unit_ctl(struct mixer_build *state, unsigned char *desc,
         cval->control = in_ch + 1; /* based on 1 */
         cval->val_type = USB_MIXER_S16;
         for (i = 0; i < num_outs; i++) {
-                if (check_matrix_bitmap(desc + 9 + input_pins, in_ch, i, num_outs)) {
+                if (check_matrix_bitmap(uac_mixer_unit_bmControls(desc), in_ch, i, num_outs)) {
                         cval->cmask |= (1 << i);
                         cval->channels++;
                 }
@@ -1132,18 +1133,19 @@ static void build_mixer_unit_ctl(struct mixer_build *state, unsigned char *desc,
 /*
  * parse a mixer unit
  */
-static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, unsigned char *desc)
+static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, void *raw_desc)
 {
+        struct uac_mixer_unit_descriptor *desc = raw_desc;
         struct usb_audio_term iterm;
         int input_pins, num_ins, num_outs;
         int pin, ich, err;
 
-        if (desc[0] < 11 || ! (input_pins = desc[4]) || ! (num_outs = desc[5 + input_pins])) {
+        if (desc->bLength < 11 || ! (input_pins = desc->bNrInPins) || ! (num_outs = uac_mixer_unit_bNrChannels(desc))) {
                 snd_printk(KERN_ERR "invalid MIXER UNIT descriptor %d\n", unitid);
                 return -EINVAL;
         }
         /* no bmControls field (e.g. Maya44) -> ignore */
-        if (desc[0] <= 10 + input_pins) {
+        if (desc->bLength <= 10 + input_pins) {
                 snd_printdd(KERN_INFO "MU %d has no bmControls field\n", unitid);
                 return 0;
         }
@@ -1151,10 +1153,10 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, unsigne
         num_ins = 0;
         ich = 0;
         for (pin = 0; pin < input_pins; pin++) {
-                err = parse_audio_unit(state, desc[5 + pin]);
+                err = parse_audio_unit(state, desc->baSourceID[pin]);
                 if (err < 0)
                         return err;
-                err = check_input_term(state, desc[5 + pin], &iterm);
+                err = check_input_term(state, desc->baSourceID[pin], &iterm);
                 if (err < 0)
                         return err;
                 num_ins += iterm.channels;
@@ -1162,7 +1164,7 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, unsigne
                         int och, ich_has_controls = 0;
 
                         for (och = 0; och < num_outs; ++och) {
-                                if (check_matrix_bitmap(desc + 9 + input_pins,
+                                if (check_matrix_bitmap(uac_mixer_unit_bmControls(desc),
                                                         ich, och, num_outs)) {
                                         ich_has_controls = 1;
                                         break;
@@ -1323,9 +1325,10 @@ static struct procunit_info extunits[] = {
 /*
  * build a processing/extension unit
  */
-static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned char *dsc, struct procunit_info *list, char *name)
+static int build_audio_procunit(struct mixer_build *state, int unitid, void *raw_desc, struct procunit_info *list, char *name)
 {
-        int num_ins = dsc[6];
+        struct uac_processing_unit_descriptor *desc = raw_desc;
+        int num_ins = desc->bNrInPins;
         struct usb_mixer_elem_info *cval;
         struct snd_kcontrol *kctl;
         int i, err, nameid, type, len;
@@ -1340,17 +1343,17 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
                 0, NULL, default_value_info
         };
 
-        if (dsc[0] < 13 || dsc[0] < 13 + num_ins || dsc[0] < num_ins + dsc[11 + num_ins]) {
+        if (desc->bLength < 13 || desc->bLength < 13 + num_ins || desc->bLength < num_ins + uac_processing_unit_bControlSize(desc)) {
                 snd_printk(KERN_ERR "invalid %s descriptor (id %d)\n", name, unitid);
                 return -EINVAL;
         }
 
         for (i = 0; i < num_ins; i++) {
-                if ((err = parse_audio_unit(state, dsc[7 + i])) < 0)
+                if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
                         return err;
         }
 
-        type = combine_word(&dsc[4]);
+        type = le16_to_cpu(desc->wProcessType);
         for (info = list; info && info->type; info++)
                 if (info->type == type)
                         break;
@@ -1358,8 +1361,9 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
                 info = &default_info;
 
         for (valinfo = info->values; valinfo->control; valinfo++) {
-                /* FIXME: bitmap might be longer than 8bit */
-                if (! (dsc[12 + num_ins] & (1 << (valinfo->control - 1))))
+                __u8 *controls = uac_processing_unit_bmControls(desc);
+
+                if (! (controls[valinfo->control / 8] & (1 << ((valinfo->control % 8) - 1))))
                         continue;
                 map = find_map(state, unitid, valinfo->control);
                 if (check_ignored_ctl(map))
@@ -1377,9 +1381,10 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
 
                 /* get min/max values */
                 if (type == USB_PROC_UPDOWN && cval->control == USB_PROC_UPDOWN_MODE_SEL) {
+                        __u8 *control_spec = uac_processing_unit_specific(desc);
                         /* FIXME: hard-coded */
                         cval->min = 1;
-                        cval->max = dsc[15];
+                        cval->max = control_spec[0];
                         cval->res = 1;
                         cval->initialized = 1;
                 } else {
@@ -1409,7 +1414,7 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
                 else if (info->name)
                         strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
                 else {
-                        nameid = dsc[12 + num_ins + dsc[11 + num_ins]];
+                        nameid = uac_processing_unit_iProcessing(desc);
                         len = 0;
                         if (nameid)
                                 len = snd_usb_copy_string_desc(state, nameid, kctl->id.name, sizeof(kctl->id.name));
@@ -1428,14 +1433,16 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, unsigned
 }
 
 
-static int parse_audio_processing_unit(struct mixer_build *state, int unitid, unsigned char *desc)
+static int parse_audio_processing_unit(struct mixer_build *state, int unitid, void *raw_desc)
 {
-        return build_audio_procunit(state, unitid, desc, procunits, "Processing Unit");
+        return build_audio_procunit(state, unitid, raw_desc, procunits, "Processing Unit");
 }
 
-static int parse_audio_extension_unit(struct mixer_build *state, int unitid, unsigned char *desc)
+static int parse_audio_extension_unit(struct mixer_build *state, int unitid, void *raw_desc)
 {
-        return build_audio_procunit(state, unitid, desc, extunits, "Extension Unit");
+        /* Note that we parse extension units with processing unit descriptors.
+         * That's ok as the layout is the same */
+        return build_audio_procunit(state, unitid, raw_desc, extunits, "Extension Unit");
 }
 
 
@@ -1537,9 +1544,9 @@ static void usb_mixer_selector_elem_free(struct snd_kcontrol *kctl)
 /*
  * parse a selector unit
  */
-static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsigned char *desc)
+static int parse_audio_selector_unit(struct mixer_build *state, int unitid, void *raw_desc)
 {
-        unsigned int num_ins = desc[4];
+        struct uac_selector_unit_descriptor *desc = raw_desc;
         unsigned int i, nameid, len;
         int err;
         struct usb_mixer_elem_info *cval;
@@ -1547,17 +1554,17 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsi
         const struct usbmix_name_map *map;
         char **namelist;
 
-        if (! num_ins || desc[0] < 5 + num_ins) {
+        if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
                 snd_printk(KERN_ERR "invalid SELECTOR UNIT descriptor %d\n", unitid);
                 return -EINVAL;
         }
 
-        for (i = 0; i < num_ins; i++) {
-                if ((err = parse_audio_unit(state, desc[5 + i])) < 0)
+        for (i = 0; i < desc->bNrInPins; i++) {
+                if ((err = parse_audio_unit(state, desc->baSourceID[i])) < 0)
                         return err;
         }
 
-        if (num_ins == 1) /* only one ? nonsense! */
+        if (desc->bNrInPins == 1) /* only one ? nonsense! */
                 return 0;
 
         map = find_map(state, unitid, 0);
@@ -1574,18 +1581,18 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsi
         cval->val_type = USB_MIXER_U8;
         cval->channels = 1;
         cval->min = 1;
-        cval->max = num_ins;
+        cval->max = desc->bNrInPins;
         cval->res = 1;
         cval->initialized = 1;
 
-        namelist = kmalloc(sizeof(char *) * num_ins, GFP_KERNEL);
+        namelist = kmalloc(sizeof(char *) * desc->bNrInPins, GFP_KERNEL);
         if (! namelist) {
                 snd_printk(KERN_ERR "cannot malloc\n");
                 kfree(cval);
                 return -ENOMEM;
         }
 #define MAX_ITEM_NAME_LEN       64
-        for (i = 0; i < num_ins; i++) {
+        for (i = 0; i < desc->bNrInPins; i++) {
                 struct usb_audio_term iterm;
                 len = 0;
                 namelist[i] = kmalloc(MAX_ITEM_NAME_LEN, GFP_KERNEL);
@@ -1599,7 +1606,7 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsi
                 }
                 len = check_mapped_selector_name(state, unitid, i, namelist[i],
                                                  MAX_ITEM_NAME_LEN);
-                if (! len && check_input_term(state, desc[5 + i], &iterm) >= 0)
+                if (! len && check_input_term(state, desc->baSourceID[i], &iterm) >= 0)
                         len = get_term_name(state, &iterm, namelist[i], MAX_ITEM_NAME_LEN, 0);
                 if (! len)
                         sprintf(namelist[i], "Input %d", i);
@@ -1615,7 +1622,7 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsi
         kctl->private_value = (unsigned long)namelist;
         kctl->private_free = usb_mixer_selector_elem_free;
 
-        nameid = desc[desc[0] - 1];
+        nameid = uac_selector_unit_iSelector(desc);
         len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
         if (len)
                 ;
@@ -1634,7 +1641,7 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid, unsi
         }
 
         snd_printdd(KERN_INFO "[%d] SU [%s] items = %d\n",
-                    cval->id, kctl->id.name, num_ins);
+                    cval->id, kctl->id.name, desc->bNrInPins);
         if ((err = add_control_to_empty(state, kctl)) < 0)
                 return err;