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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-20 18:41:44 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-20 18:41:44 +0200 |
commit | 7f06a8b26aba1dc03b42272dc0089a800372c575 (patch) | |
tree | 7c67198f83d069eb13fd417e022d111b7e4c82a1 /sound/usb/helper.c | |
parent | Merge branch 'for-linus/i2c-2635' of git://git.fluff.org/bjdooks/linux (diff) | |
parent | Merge branch 'topic/asoc' into for-linus (diff) | |
download | linux-7f06a8b26aba1dc03b42272dc0089a800372c575.tar.xz linux-7f06a8b26aba1dc03b42272dc0089a800372c575.zip |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (250 commits)
ALSA: hda: Storage class should be before const qualifier
ASoC: tpa6130a2: Remove CPVSS and HPVdd supplies
ASoC: tpa6130a2: Define output pins with SND_SOC_DAPM_OUTPUT
ASoC: sdp4430 - add sdp4430 pcm ops to DAI.
ASoC: TWL6040: Enable earphone path in codec
ASoC: SDP4430: Add support for Earphone speaker
ASoC: SDP4430: Add sdp4430 machine driver
ASoC: tlv320dac33: Avoid powering off while in BIAS_OFF
ASoC: tlv320dac33: Use dev_dbg in dac33_hard_power function
ALSA: sound/pci/asihpi: Use kzalloc
ALSA: hdmi - dont fail on extra nodes
ALSA: intelhdmi - add id for the CougarPoint chipset
ALSA: intelhdmi - user friendly codec name
ALSA: intelhdmi - add dependency on SND_DYNAMIC_MINORS
ALSA: asihpi: incorrect range check
ALSA: asihpi: testing the wrong variable
ALSA: es1688: add pedantic range checks
ARM: McBSP: Add support for omap4 in McBSP driver
ARM: McBSP: Fix request for irq in OMAP4
OMAP: McBSP: Add 32-bit mode support
...
Diffstat (limited to 'sound/usb/helper.c')
-rw-r--r-- | sound/usb/helper.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sound/usb/helper.c b/sound/usb/helper.c new file mode 100644 index 000000000000..d48d6f8f6ac9 --- /dev/null +++ b/sound/usb/helper.c @@ -0,0 +1,113 @@ +/* + * 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/slab.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; +} + |