ALSA: usb-audio: refactor code

Clean up the usb audio driver by factoring out a lot of functions to
separate files. Code for procfs, quirks, urbs, format parsers etc all
got a new home now.

Moved almost all special quirk handling to quirks.c and introduced new
generic functions to handle them, so the exceptions do not pollute the
whole driver.

Renamed usbaudio.c to card.c because this is what it actually does now.
Renamed usbmidi.c to midi.c for namespace clarity.
Removed more things from usbaudio.h.

The non-standard drivers were adopted accordingly.

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, 112 insertions, 0 deletions

diff --git a/sound/usb/helper.c b/sound/usb/helper.c
new file mode 100644
index 000000000000..ba7dba4d5cf2
--- /dev/null
+++ b/sound/usb/helper.c
@@ -0,0 +1,112 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+
+#include "usbaudio.h"
+#include "helper.h"
+
+/*
+ * combine bytes and get an integer value
+ */
+unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
+{
+	switch (size) {
+	case 1:  return *bytes;
+	case 2:  return combine_word(bytes);
+	case 3:  return combine_triple(bytes);
+	case 4:  return combine_quad(bytes);
+	default: return 0;
+	}
+}
+
+/*
+ * parse descriptor buffer and return the pointer starting the given
+ * descriptor type.
+ */
+void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
+{
+	u8 *p, *end, *next;
+
+	p = descstart;
+	end = p + desclen;
+	for (; p < end;) {
+		if (p[0] < 2)
+			return NULL;
+		next = p + p[0];
+		if (next > end)
+			return NULL;
+		if (p[1] == dtype && (!after || (void *)p > after)) {
+			return p;
+		}
+		p = next;
+	}
+	return NULL;
+}
+
+/*
+ * find a class-specified interface descriptor with the given subtype.
+ */
+void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
+{
+	unsigned char *p = after;
+
+	while ((p = snd_usb_find_desc(buffer, buflen, p,
+				      USB_DT_CS_INTERFACE)) != NULL) {
+		if (p[0] >= 3 && p[2] == dsubtype)
+			return p;
+	}
+	return NULL;
+}
+
+/*
+ * Wrapper for usb_control_msg().
+ * Allocates a temp buffer to prevent dmaing from/to the stack.
+ */
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
+		    __u8 requesttype, __u16 value, __u16 index, void *data,
+		    __u16 size, int timeout)
+{
+	int err;
+	void *buf = NULL;
+
+	if (size > 0) {
+		buf = kmemdup(data, size, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+	}
+	err = usb_control_msg(dev, pipe, request, requesttype,
+			      value, index, buf, size, timeout);
+	if (size > 0) {
+		memcpy(data, buf, size);
+		kfree(buf);
+	}
+	return err;
+}
+
+unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
+					 struct usb_host_interface *alts)
+{
+	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH &&
+	    get_endpoint(alts, 0)->bInterval >= 1 &&
+	    get_endpoint(alts, 0)->bInterval <= 4)
+		return get_endpoint(alts, 0)->bInterval - 1;
+	else
+		return 0;
+}
+