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usb: gadget: f_uac2: Support multiple sampling rates 
A list of sampling rates can be specified via configfs. All enabled
sampling rates are sent to the USB host on request. When the host
selects a sampling rate, the internal active rate (stored in
struct f_uac2) is updated.

The gadget no longer supports only one frequency. Therefore USB strings
corresponding to the clock sources are renamed from specific Hz value to
general names Input clock/Output clock.

Config strings with single value stay compatible with the previous
version.

Multiple samplerates passed as configuration arrays to g_audio module
when built for f_uac2.

Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
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@julianscheel @intel-lab-lkp
julianscheel authored and intel-lab-lkp committed Jan 10, 2022
1 parent 79fb4d0 commit 275344f5925d7804375e3572fd2fbd1febb029a6
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Showing 5 changed files with 182 additions and 54 deletions.
4 Documentation/ABI/testing/configfs-usb-gadget-uac2
View file
@@ -6,7 +6,7 @@ Description:

===================== =======================================
c_chmask capture channel mask
c_srate capture sampling rate
c_srate list of capture sampling rates (comma-separated)
c_ssize capture sample size (bytes)
c_sync capture synchronization type
(async/adaptive)
@@ -20,7 +20,7 @@ Description:
(in 1/256 dB)
fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate playback sampling rate
p_srate list of playback sampling rates (comma-separated)
p_ssize playback sample size (bytes)
p_mute_present playback mute control enable
p_volume_present playback volume control enable
4 Documentation/usb/gadget-testing.rst
View file
@@ -726,7 +726,7 @@ The uac2 function provides these attributes in its function directory:

================ ====================================================
c_chmask capture channel mask
c_srate capture sampling rate
c_srate list of capture sampling rates (comma-separated)
c_ssize capture sample size (bytes)
c_sync capture synchronization type (async/adaptive)
c_mute_present capture mute control enable
@@ -736,7 +736,7 @@ The uac2 function provides these attributes in its function directory:
c_volume_res capture volume control resolution (in 1/256 dB)
fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate playback sampling rate
p_srate list of playback sampling rates (comma-separated)
p_ssize playback sample size (bytes)
p_mute_present playback mute control enable
p_volume_present playback volume control enable
198 drivers/usb/gadget/function/f_uac2.c
View file
@@ -70,6 +70,8 @@ struct f_uac2 {
/* Interrupt IN endpoint of AC interface */
struct usb_ep *int_ep;
atomic_t int_count;
/* transient state, only valid during handling of a single control request */
int clock_id;
};

static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
@@ -104,14 +106,11 @@ enum {
STR_AS_IN_ALT1,
};

static char clksrc_in[8];
static char clksrc_out[8];

static struct usb_string strings_fn[] = {
[STR_ASSOC].s = "Source/Sink",
[STR_IF_CTRL].s = "Topology Control",
[STR_CLKSRC_IN].s = clksrc_in,
[STR_CLKSRC_OUT].s = clksrc_out,
[STR_CLKSRC_IN].s = "Input Clock",
[STR_CLKSRC_OUT].s = "Output Clock",
[STR_USB_IT].s = "USBH Out",
[STR_IO_IT].s = "USBD Out",
[STR_USB_OT].s = "USBH In",
@@ -166,7 +165,7 @@ static struct uac_clock_source_descriptor in_clk_src_desc = {
.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
/* .bClockID = DYNAMIC */
.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
.bmControls = (CONTROL_RDWR << CLK_FREQ_CTRL),
.bAssocTerminal = 0,
};

@@ -178,7 +177,7 @@ static struct uac_clock_source_descriptor out_clk_src_desc = {
.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
/* .bClockID = DYNAMIC */
.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
.bmControls = (CONTROL_RDWR << CLK_FREQ_CTRL),
.bAssocTerminal = 0,
};

@@ -634,13 +633,36 @@ struct cntrl_cur_lay3 {
__le32 dCUR;
};

struct cntrl_range_lay3 {
__le16 wNumSubRanges;
struct cntrl_subrange_lay3 {
__le32 dMIN;
__le32 dMAX;
__le32 dRES;
} __packed;

#define ranges_lay3_size(c) (sizeof(c.wNumSubRanges) + c.wNumSubRanges \
* sizeof(struct cntrl_subrange_lay3))

#define DECLARE_UAC2_CNTRL_RANGES_LAY3(k, n) \
struct cntrl_ranges_lay3_##k { \
__le16 wNumSubRanges; \
struct cntrl_subrange_lay3 r[n]; \
} __packed

DECLARE_UAC2_CNTRL_RANGES_LAY3(srates, UAC_MAX_RATES);

static int get_max_srate(const int *srates)
{
int i, max_srate = 0;

for (i = 0; i < UAC_MAX_RATES; i++) {
if (srates[i] == 0)
break;
if (srates[i] > max_srate)
max_srate = srates[i];
}
return max_srate;
}

static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
struct usb_endpoint_descriptor *ep_desc,
enum usb_device_speed speed, bool is_playback)
@@ -667,11 +689,11 @@ static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,

if (is_playback) {
chmask = uac2_opts->p_chmask;
srate = uac2_opts->p_srate;
srate = get_max_srate(uac2_opts->p_srates);
ssize = uac2_opts->p_ssize;
} else {
chmask = uac2_opts->c_chmask;
srate = uac2_opts->c_srate;
srate = get_max_srate(uac2_opts->c_srates);
ssize = uac2_opts->c_ssize;
}

@@ -912,10 +934,10 @@ static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
} else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
dev_err(dev, "Error: incorrect capture sample size\n");
return -EINVAL;
} else if (!opts->p_srate) {
} else if (!opts->p_srates[0]) {
dev_err(dev, "Error: incorrect playback sampling rate\n");
return -EINVAL;
} else if (!opts->c_srate) {
} else if (!opts->c_srates[0]) {
dev_err(dev, "Error: incorrect capture sampling rate\n");
return -EINVAL;
}
@@ -1037,9 +1059,6 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
*bma = cpu_to_le32(control);
}

snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);

ret = usb_interface_id(cfg, fn);
if (ret < 0) {
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
@@ -1209,7 +1228,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->gadget = gadget;

agdev->params.p_chmask = uac2_opts->p_chmask;
agdev->params.p_srates[0] = uac2_opts->p_srate;
memcpy(agdev->params.p_srates, uac2_opts->p_srates,
sizeof(agdev->params.p_srates));
agdev->params.p_ssize = uac2_opts->p_ssize;
if (FUIN_EN(uac2_opts)) {
agdev->params.p_fu.id = USB_IN_FU_ID;
@@ -1220,7 +1240,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->params.p_fu.volume_res = uac2_opts->p_volume_res;
}
agdev->params.c_chmask = uac2_opts->c_chmask;
agdev->params.c_srates[0] = uac2_opts->c_srate;
memcpy(agdev->params.c_srates, uac2_opts->c_srates,
sizeof(agdev->params.c_srates));
agdev->params.c_ssize = uac2_opts->c_ssize;
if (FUOUT_EN(uac2_opts)) {
agdev->params.c_fu.id = USB_OUT_FU_ID;
@@ -1423,10 +1444,10 @@ in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
u8 entity_id = (w_index >> 8) & 0xff;
u8 control_selector = w_value >> 8;
int value = -EOPNOTSUPP;
int p_srate, c_srate;
u32 p_srate, c_srate;

p_srate = opts->p_srate;
c_srate = opts->c_srate;
u_audio_get_playback_srate(agdev, &p_srate);
u_audio_get_capture_srate(agdev, &c_srate);

if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
@@ -1500,28 +1521,39 @@ in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
u8 entity_id = (w_index >> 8) & 0xff;
u8 control_selector = w_value >> 8;
int value = -EOPNOTSUPP;
int p_srate, c_srate;

p_srate = opts->p_srate;
c_srate = opts->c_srate;

if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
struct cntrl_range_lay3 r;
struct cntrl_ranges_lay3_srates rs;
int i;
int wNumSubRanges = 0;
int srate;
int *srates;

if (entity_id == USB_IN_CLK_ID)
r.dMIN = cpu_to_le32(p_srate);
srates = opts->p_srates;
else if (entity_id == USB_OUT_CLK_ID)
r.dMIN = cpu_to_le32(c_srate);
srates = opts->c_srates;
else
return -EOPNOTSUPP;

r.dMAX = r.dMIN;
r.dRES = 0;
r.wNumSubRanges = cpu_to_le16(1);

value = min_t(unsigned int, w_length, sizeof(r));
memcpy(req->buf, &r, value);
for (i = 0; i < UAC_MAX_RATES; i++) {
srate = srates[i];
if (srate == 0)
break;

rs.r[wNumSubRanges].dMIN = cpu_to_le32(srate);
rs.r[wNumSubRanges].dMAX = cpu_to_le32(srate);
rs.r[wNumSubRanges].dRES = 0;
wNumSubRanges++;
dev_dbg(&agdev->gadget->dev,
"%s(): clk %d: rate ID %d: %d\n",
__func__, entity_id, wNumSubRanges, srate);
}
rs.wNumSubRanges = cpu_to_le16(wNumSubRanges);
value = min_t(unsigned int, w_length, ranges_lay3_size(rs));
dev_dbg(&agdev->gadget->dev, "%s(): sending %d rates, size %d\n",
__func__, rs.wNumSubRanges, value);
memcpy(req->buf, &rs, value);
} else {
dev_err(&agdev->gadget->dev,
"%s:%d control_selector=%d TODO!\n",
@@ -1580,6 +1612,25 @@ ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
return -EOPNOTSUPP;
}

static void uac2_cs_control_sam_freq(struct usb_ep *ep, struct usb_request *req)
{
struct usb_function *fn = ep->driver_data;
struct g_audio *agdev = func_to_g_audio(fn);
struct f_uac2 *uac2 = func_to_uac2(fn);
u32 val;

if (req->actual != 4)
return;

val = le32_to_cpu(*((u32 *)req->buf));
dev_dbg(&agdev->gadget->dev, "%s val: %d.\n", __func__, val);
if (uac2->clock_id == USB_IN_CLK_ID) {
u_audio_set_playback_srate(agdev, val);
} else if (uac2->clock_id == USB_OUT_CLK_ID) {
u_audio_set_capture_srate(agdev, val);
}
}

static void
out_rq_cur_complete(struct usb_ep *ep, struct usb_request *req)
{
@@ -1631,6 +1682,7 @@ out_rq_cur_complete(struct usb_ep *ep, struct usb_request *req)
static int
out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
struct usb_composite_dev *cdev = fn->config->cdev;
struct usb_request *req = fn->config->cdev->req;
struct g_audio *agdev = func_to_g_audio(fn);
struct f_uac2_opts *opts = g_audio_to_uac2_opts(agdev);
@@ -1640,10 +1692,17 @@ out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
u16 w_value = le16_to_cpu(cr->wValue);
u8 entity_id = (w_index >> 8) & 0xff;
u8 control_selector = w_value >> 8;
u8 clock_id = w_index >> 8;

if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
dev_dbg(&agdev->gadget->dev,
"control_selector UAC2_CS_CONTROL_SAM_FREQ, clock: %d\n", clock_id);
cdev->gadget->ep0->driver_data = fn;
uac2->clock_id = clock_id;
req->complete = uac2_cs_control_sam_freq;
return w_length;
}
} else if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
(FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
memcpy(&uac2->setup_cr, cr, sizeof(*cr));
@@ -1836,11 +1895,70 @@ end: \
\
CONFIGFS_ATTR(f_uac2_opts_, name)

#define UAC2_RATE_ATTRIBUTE(name) \
static ssize_t f_uac2_opts_##name##_show(struct config_item *item, \
char *page) \
{ \
struct f_uac2_opts *opts = to_f_uac2_opts(item); \
int result = 0; \
int i; \
\
mutex_lock(&opts->lock); \
page[0] = '\0'; \
for (i = 0; i < UAC_MAX_RATES; i++) { \
if (opts->name##s[i] == 0) \
break; \
result += sprintf(page + strlen(page), "%u,", \
opts->name##s[i]); \
} \
if (strlen(page) > 0) \
page[strlen(page) - 1] = '\n'; \
mutex_unlock(&opts->lock); \
\
return result; \
} \
\
static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \
const char *page, size_t len) \
{ \
struct f_uac2_opts *opts = to_f_uac2_opts(item); \
char *split_page = NULL; \
int ret = -EINVAL; \
char *token; \
u32 num; \
int i; \
\
mutex_lock(&opts->lock); \
if (opts->refcnt) { \
ret = -EBUSY; \
goto end; \
} \
\
i = 0; \
memset(opts->name##s, 0x00, sizeof(opts->name##s)); \
split_page = kstrdup(page, GFP_KERNEL); \
while ((token = strsep(&split_page, ",")) != NULL) { \
ret = kstrtou32(token, 0, &num); \
if (ret) \
goto end; \
\
opts->name##s[i++] = num; \
ret = len; \
}; \
\
end: \
kfree(split_page); \
mutex_unlock(&opts->lock); \
return ret; \
} \
\
CONFIGFS_ATTR(f_uac2_opts_, name)

UAC2_ATTRIBUTE(u32, p_chmask);
UAC2_ATTRIBUTE(u32, p_srate);
UAC2_RATE_ATTRIBUTE(p_srate);
UAC2_ATTRIBUTE(u32, p_ssize);
UAC2_ATTRIBUTE(u32, c_chmask);
UAC2_ATTRIBUTE(u32, c_srate);
UAC2_RATE_ATTRIBUTE(c_srate);
UAC2_ATTRIBUTE_SYNC(c_sync);
UAC2_ATTRIBUTE(u32, c_ssize);
UAC2_ATTRIBUTE(u32, req_number);
@@ -1913,10 +2031,10 @@ static struct usb_function_instance *afunc_alloc_inst(void)
&f_uac2_func_type);

opts->p_chmask = UAC2_DEF_PCHMASK;
opts->p_srate = UAC2_DEF_PSRATE;
opts->p_srates[0] = UAC2_DEF_PSRATE;
opts->p_ssize = UAC2_DEF_PSSIZE;
opts->c_chmask = UAC2_DEF_CCHMASK;
opts->c_srate = UAC2_DEF_CSRATE;
opts->c_srates[0] = UAC2_DEF_CSRATE;
opts->c_ssize = UAC2_DEF_CSSIZE;
opts->c_sync = UAC2_DEF_CSYNC;

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