ALSA: usb-audio: Refactor clock finder helpers

There are lots of open-coded functions to find a clock source,
selector and multiplier.  Now there are both v2 and v3, so six
variants.

This patch refactors the code to use a common helper for the main
loop, and define each validator function for each target.
There is no functional change.

Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support")
Reviewed-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index ab39ccb..27c2275 100644 (file)
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -35,105 +35,84 @@
 #include "clock.h"
 #include "quirks.h"
 
-static struct uac_clock_source_descriptor *
-       snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
-                                 int clock_id)
+static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
+                                bool (*validator)(void *, int), u8 type)
 {
-       struct uac_clock_source_descriptor *cs = NULL;
+       void *cs = NULL;
 
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC2_CLOCK_SOURCE))) {
-               if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
+       while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
+                                            cs, type))) {
+               if (validator(cs, id))
                        return cs;
        }
 
        return NULL;
 }
 
-static struct uac3_clock_source_descriptor *
-       snd_usb_find_clock_source_v3(struct usb_host_interface *ctrl_iface,
-                                 int clock_id)
+static bool validate_clock_source_v2(void *p, int id)
 {
-       struct uac3_clock_source_descriptor *cs = NULL;
-
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC3_CLOCK_SOURCE))) {
-               if (cs->bClockID == clock_id)
-                       return cs;
-       }
-
-       return NULL;
+       struct uac_clock_source_descriptor *cs = p;
+       return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
 }
 
-static struct uac_clock_selector_descriptor *
-       snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
-                                   int clock_id)
+static bool validate_clock_source_v3(void *p, int id)
 {
-       struct uac_clock_selector_descriptor *cs = NULL;
-
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC2_CLOCK_SELECTOR))) {
-               if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {
-                       if (cs->bLength < 5 + cs->bNrInPins)
-                               return NULL;
-                       return cs;
-               }
-       }
-
-       return NULL;
+       struct uac3_clock_source_descriptor *cs = p;
+       return cs->bClockID == id;
 }
 
-static struct uac3_clock_selector_descriptor *
-       snd_usb_find_clock_selector_v3(struct usb_host_interface *ctrl_iface,
-                                   int clock_id)
+static bool validate_clock_selector_v2(void *p, int id)
 {
-       struct uac3_clock_selector_descriptor *cs = NULL;
-
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC3_CLOCK_SELECTOR))) {
-               if (cs->bClockID == clock_id)
-                       return cs;
-       }
-
-       return NULL;
+       struct uac_clock_selector_descriptor *cs = p;
+       return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
+               cs->bLength >= 5 + cs->bNrInPins;
 }
 
-static struct uac_clock_multiplier_descriptor *
-       snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
-                                     int clock_id)
+static bool validate_clock_selector_v3(void *p, int id)
 {
-       struct uac_clock_multiplier_descriptor *cs = NULL;
-
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC2_CLOCK_MULTIPLIER))) {
-               if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
-                       return cs;
-       }
-
-       return NULL;
+       struct uac3_clock_selector_descriptor *cs = p;
+       return cs->bClockID == id;
 }
 
-static struct uac3_clock_multiplier_descriptor *
-       snd_usb_find_clock_multiplier_v3(struct usb_host_interface *ctrl_iface,
-                                     int clock_id)
+static bool validate_clock_multiplier_v2(void *p, int id)
 {
-       struct uac3_clock_multiplier_descriptor *cs = NULL;
+       struct uac_clock_multiplier_descriptor *cs = p;
+       return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
+}
 
-       while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
-                                            ctrl_iface->extralen,
-                                            cs, UAC3_CLOCK_MULTIPLIER))) {
-               if (cs->bClockID == clock_id)
-                       return cs;
-       }
+static bool validate_clock_multiplier_v3(void *p, int id)
+{
+       struct uac3_clock_multiplier_descriptor *cs = p;
+       return cs->bClockID == id;
+}
 
-       return NULL;
+#define DEFINE_FIND_HELPER(name, obj, validator, type)         \
+static obj *name(struct usb_host_interface *iface, int id)     \
+{                                                              \
+       return find_uac_clock_desc(iface, id, validator, type); \
 }
 
+DEFINE_FIND_HELPER(snd_usb_find_clock_source,
+                  struct uac_clock_source_descriptor,
+                  validate_clock_source_v2, UAC2_CLOCK_SOURCE);
+DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
+                  struct uac3_clock_source_descriptor,
+                  validate_clock_source_v3, UAC3_CLOCK_SOURCE);
+
+DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
+                  struct uac_clock_selector_descriptor,
+                  validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
+DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
+                  struct uac3_clock_selector_descriptor,
+                  validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
+
+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
+                  struct uac_clock_multiplier_descriptor,
+                  validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
+                  struct uac3_clock_multiplier_descriptor,
+                  validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
+
 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
 {
        unsigned char buf;