UPSTREAM: usb: gadget: f_uac1: allow changing interface name via configfs

This adds "function_name" configfs entry to change string value
of the iInterface field. This field will be shown in Windows' audio
settings panel, so being able to change it is useful. It will default
to "AC Interface" just as before if unchanged.

Signed-off-by: Yunhao Tian <t123yh.xyz@gmail.com>
Link: https://lore.kernel.org/r/20220122112446.1415547-1-t123yh.xyz@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bug: 235196743
(cherry picked from commit dfb05b5dc3afd90e564b69b88ff6be6947a0f32f)
Change-Id: Ibd0e417ab82efe1fb3aa6fd5bb33fb70f113cf1a
Signed-off-by: Luiz Matheus <luizmmat@motorola.com>
This commit is contained in:
Yunhao Tian 2022-01-22 19:24:40 +08:00 committed by Treehugger Robot
parent 29172165ca
commit 98fa7f7dfd
4 changed files with 49 additions and 1 deletions

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@ -29,4 +29,5 @@ Description:
(in 1/256 dB)
req_number the number of pre-allocated requests
for both capture and playback
function_name name of the interface
===================== =======================================

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@ -745,6 +745,7 @@ The uac2 function provides these attributes in its function directory:
p_volume_res playback volume control resolution (in 1/256 dB)
req_number the number of pre-allocated request for both capture
and playback
function_name name of the interface
================ ====================================================
The attributes have sane default values.

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@ -309,7 +309,7 @@ enum {
};
static struct usb_string strings_uac1[] = {
[STR_AC_IF].s = "AC Interface",
/* [STR_AC_IF].s = DYNAMIC, */
[STR_USB_OUT_IT].s = "Playback Input terminal",
[STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
[STR_IO_OUT_OT].s = "Playback Output terminal",
@ -1192,6 +1192,8 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
strings_uac1[STR_AC_IF].s = audio_opts->function_name;
us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
if (IS_ERR(us))
return PTR_ERR(us);
@ -1551,6 +1553,42 @@ end: \
\
CONFIGFS_ATTR(f_uac1_opts_, name)
#define UAC1_ATTRIBUTE_STRING(name) \
static ssize_t f_uac1_opts_##name##_show(struct config_item *item, \
char *page) \
{ \
struct f_uac1_opts *opts = to_f_uac1_opts(item); \
int result; \
\
mutex_lock(&opts->lock); \
result = snprintf(page, sizeof(opts->name), "%s", opts->name); \
mutex_unlock(&opts->lock); \
\
return result; \
} \
\
static ssize_t f_uac1_opts_##name##_store(struct config_item *item, \
const char *page, size_t len) \
{ \
struct f_uac1_opts *opts = to_f_uac1_opts(item); \
int ret = 0; \
\
mutex_lock(&opts->lock); \
if (opts->refcnt) { \
ret = -EBUSY; \
goto end; \
} \
\
ret = snprintf(opts->name, min(sizeof(opts->name), len), \
"%s", page); \
\
end: \
mutex_unlock(&opts->lock); \
return ret; \
} \
\
CONFIGFS_ATTR(f_uac1_opts_, name)
UAC1_ATTRIBUTE(u32, c_chmask);
UAC1_RATE_ATTRIBUTE(c_srate);
UAC1_ATTRIBUTE(u32, c_ssize);
@ -1570,6 +1608,7 @@ UAC1_ATTRIBUTE(bool, c_volume_present);
UAC1_ATTRIBUTE(s16, c_volume_min);
UAC1_ATTRIBUTE(s16, c_volume_max);
UAC1_ATTRIBUTE(s16, c_volume_res);
UAC1_ATTRIBUTE_STRING(function_name);
static struct configfs_attribute *f_uac1_attrs[] = {
&f_uac1_opts_attr_c_chmask,
@ -1592,6 +1631,8 @@ static struct configfs_attribute *f_uac1_attrs[] = {
&f_uac1_opts_attr_c_volume_max,
&f_uac1_opts_attr_c_volume_res,
&f_uac1_opts_attr_function_name,
NULL,
};
@ -1643,6 +1684,9 @@ static struct usb_function_instance *f_audio_alloc_inst(void)
opts->c_volume_res = UAC1_DEF_RES_DB;
opts->req_number = UAC1_DEF_REQ_NUM;
snprintf(opts->function_name, sizeof(opts->function_name), "AC Interface");
return &opts->func_inst;
}

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@ -52,6 +52,8 @@ struct f_uac1_opts {
int req_number;
unsigned bound:1;
char function_name[32];
struct mutex lock;
int refcnt;
};