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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /sound/usb/helper.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sound/usb/helper.c')
-rw-r--r-- | sound/usb/helper.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/sound/usb/helper.c b/sound/usb/helper.c new file mode 100644 index 000000000..7712e2b84 --- /dev/null +++ b/sound/usb/helper.c @@ -0,0 +1,133 @@ +/* + * 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" +#include "quirks.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 err; + void *buf = NULL; + int timeout; + + if (size > 0) { + buf = kmemdup(data, size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + } + + if (requesttype & USB_DIR_IN) + timeout = USB_CTRL_GET_TIMEOUT; + else + timeout = USB_CTRL_SET_TIMEOUT; + + err = usb_control_msg(dev, pipe, request, requesttype, + value, index, buf, size, timeout); + + if (size > 0) { + memcpy(data, buf, size); + kfree(buf); + } + + snd_usb_ctl_msg_quirk(dev, pipe, request, requesttype, + value, index, data, size); + + return err; +} + +unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip, + struct usb_host_interface *alts) +{ + switch (snd_usb_get_speed(chip->dev)) { + case USB_SPEED_HIGH: + case USB_SPEED_WIRELESS: + case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: + if (get_endpoint(alts, 0)->bInterval >= 1 && + get_endpoint(alts, 0)->bInterval <= 4) + return get_endpoint(alts, 0)->bInterval - 1; + break; + default: + break; + } + return 0; +} + |