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Merge pull request #1381 from hathach/add-sof-isr

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Add SOF IRQ Handler
This commit is contained in:
Ha Thach
2022-05-31 22:25:14 +07:00
committed by GitHub
parent ab7c23a787 e384d16d57
commit fdeac8508b
38 changed files with 631 additions and 2821 deletions
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265
src/class/audio/audio_device.c
View File

@@ -305,9 +305,35 @@ typedef struct
#endif
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
uint32_t fb_val; // Feedback value for asynchronous mode (in 16.16 format).
#endif
struct {
uint32_t value; // Feedback value for asynchronous mode (in 16.16 format).
uint32_t min_value; // min value according to UAC2 FMT-2.0 section 2.3.1.1.
uint32_t max_value; // max value according to UAC2 FMT-2.0 section 2.3.1.1.
uint8_t frame_shift; // bInterval-1 in unit of frame (FS), micro-frame (HS)
uint8_t compute_method;
union {
uint8_t power_of_2; // pre-computed power of 2 shift
float float_const; // pre-computed float constant
struct {
uint32_t sample_freq;
uint32_t mclk_freq;
}fixed;
#if 0 // implement later
struct {
uint32_t nominal_value;
uint32_t threshold_bytes;
}fifo_count;
#endif
}compute;
} feedback;
#endif // CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
#endif // CFG_TUD_AUDIO_ENABLE_EP_OUT
#if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
tu_fifo_t ep_in_ff;
@@ -1039,7 +1065,7 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
static inline bool audiod_fb_send(uint8_t rhport, audiod_function_t *audio)
{
return usbd_edpt_xfer(rhport, audio->ep_fb, (uint8_t *) &audio->fb_val, 4);
return usbd_edpt_xfer(rhport, audio->ep_fb, (uint8_t *) &audio->feedback.value, 4);
}
#endif
@@ -1510,7 +1536,7 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
tu_fifo_clear(&audio->tx_supp_ff[cnt]);
}
#endif
// Invoke callback - can be used to stop data sampling
if (tud_audio_set_itf_close_EP_cb) TU_VERIFY(tud_audio_set_itf_close_EP_cb(rhport, p_request));
@@ -1543,7 +1569,8 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
// Close corresponding feedback EP
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
usbd_edpt_close(rhport, audio->ep_fb);
audio->ep_fb = 0; // Necessary?
audio->ep_fb = 0;
tu_memclr(&audio->feedback, sizeof(audio->feedback));
#endif
}
#endif
@@ -1602,8 +1629,6 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
#endif
#endif
// Invoke callback - can be used to trigger data sampling if not already running
if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
// Schedule first transmit if alternate interface is not zero i.e. streaming is disabled - in case no sample data is available a ZLP is loaded
// It is necessary to trigger this here since the refill is done with an RX FIFO empty interrupt which can only trigger if something was in there
@@ -1635,16 +1660,6 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
#endif
#endif
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
// In case of asynchronous EP, call Cb after ep_fb is set
if ( !(desc_ep->bmAttributes.sync == 0x01 && audio->ep_fb == 0) )
{
if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
}
#else
// Invoke callback
if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
#endif
// Prepare for incoming data
#if USE_LINEAR_BUFFER_RX
TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_out, audio->lin_buf_out, audio->ep_out_sz), false);
@@ -1657,12 +1672,10 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN && desc_ep->bmAttributes.usage == 1) // Check if usage is explicit data feedback
{
audio->ep_fb = ep_addr;
audio->feedback.frame_shift = desc_ep->bInterval -1;
// Invoke callback after ep_out is set
if (audio->ep_out != 0)
{
if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
}
// Enable SOF interrupt if callback is implemented
if (tud_audio_feedback_interval_isr) usbd_sof_enable(rhport, true);
}
#endif
#endif // CFG_TUD_AUDIO_ENABLE_EP_OUT
@@ -1674,6 +1687,49 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
TU_VERIFY(foundEPs == nEps);
// Invoke one callback for a final set interface
if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
// Prepare feedback computation if callback is available
if (tud_audio_feedback_params_cb)
{
audio_feedback_params_t fb_param;
tud_audio_feedback_params_cb(func_id, alt, &fb_param);
audio->feedback.compute_method = fb_param.method;
// Minimal/Maximum value in 16.16 format for full speed (1ms per frame) or high speed (125 us per frame)
uint32_t const frame_div = (TUSB_SPEED_FULL == tud_speed_get()) ? 1000 : 8000;
audio->feedback.min_value = (fb_param.sample_freq/frame_div - 1) << 16;
audio->feedback.max_value = (fb_param.sample_freq/frame_div + 1) << 16;
switch(fb_param.method)
{
case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
set_fb_params_freq(audio, fb_param.sample_freq, fb_param.frequency.mclk_freq);
break;
#if 0 // implement later
case AUDIO_FEEDBACK_METHOD_FIFO_COUNT:
{
uint64_t fb64 = ((uint64_t) fb_param.sample_freq) << 16;
audio->feedback.compute.fifo_count.nominal_value = (uint32_t) (fb64 / frame_div);
audio->feedback.compute.fifo_count.threshold_bytes = fb_param.fifo_count.threshold_bytes;
tud_audio_fb_set(audio->feedback.compute.fifo_count.nominal_value);
}
break;
#endif
// nothing to do
default: break;
}
}
#endif
// We are done - abort loop
break;
}
@@ -1682,6 +1738,20 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
p_desc = tu_desc_next(p_desc);
}
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
// Disable SOF interrupt if no driver has any enabled feedback EP
bool disable = true;
for(uint8_t i=0; i < CFG_TUD_AUDIO; i++)
{
if (_audiod_fct[i].ep_fb != 0)
{
disable = false;
break;
}
}
if (disable) usbd_sof_enable(rhport, false);
#endif
tud_control_status(rhport, p_request);
return true;
@@ -1898,14 +1968,14 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
(void) xferred_bytes;
// Search for interface belonging to given end point address and proceed as required
uint8_t func_id;
for (func_id = 0; func_id < CFG_TUD_AUDIO; func_id++)
for (uint8_t func_id = 0; func_id < CFG_TUD_AUDIO; func_id++)
{
audiod_function_t* audio = &_audiod_fct[func_id];
#if CFG_TUD_AUDIO_INT_CTR_EPSIZE_IN
// Data transmission of control interrupt finished
if (_audiod_fct[func_id].ep_int_ctr == ep_addr)
if (audio->ep_int_ctr == ep_addr)
{
// According to USB2 specification, maximum payload of interrupt EP is 8 bytes on low speed, 64 bytes on full speed, and 1024 bytes on high speed (but only if an alternate interface other than 0 is used - see specification p. 49)
// In case there is nothing to send we have to return a NAK - this is taken care of by PHY ???
@@ -1922,7 +1992,7 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
#if CFG_TUD_AUDIO_ENABLE_EP_IN
// Data transmission of audio packet finished
if (_audiod_fct[func_id].ep_in == ep_addr && _audiod_fct[func_id].alt_setting != 0)
if (audio->ep_in == ep_addr && audio->alt_setting != 0)
{
// USB 2.0, section 5.6.4, third paragraph, states "An isochronous endpoint must specify its required bus access period. However, an isochronous endpoint must be prepared to handle poll rates faster than the one specified."
// That paragraph goes on to say "An isochronous IN endpoint must return a zero-length packet whenever data is requested at a faster interval than the specified interval and data is not available."
@@ -1933,7 +2003,7 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
// This is the only place where we can fill something into the EPs buffer!
// Load new data
TU_VERIFY(audiod_tx_done_cb(rhport, &_audiod_fct[func_id]));
TU_VERIFY(audiod_tx_done_cb(rhport, audio));
// Transmission of ZLP is done by audiod_tx_done_cb()
return true;
@@ -1943,24 +2013,24 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
#if CFG_TUD_AUDIO_ENABLE_EP_OUT
// New audio packet received
if (_audiod_fct[func_id].ep_out == ep_addr)
if (audio->ep_out == ep_addr)
{
TU_VERIFY(audiod_rx_done_cb(rhport, &_audiod_fct[func_id], (uint16_t) xferred_bytes));
TU_VERIFY(audiod_rx_done_cb(rhport, audio, (uint16_t) xferred_bytes));
return true;
}
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
// Transmission of feedback EP finished
if (_audiod_fct[func_id].ep_fb == ep_addr)
if (audio->ep_fb == ep_addr)
{
if (tud_audio_fb_done_cb) TU_VERIFY(tud_audio_fb_done_cb(rhport));
if (tud_audio_fb_done_cb) tud_audio_fb_done_cb(func_id);
// Schedule a transmit with the new value if EP is not busy
if (!usbd_edpt_busy(rhport, _audiod_fct[func_id].ep_fb))
if (!usbd_edpt_busy(rhport, audio->ep_fb))
{
// Schedule next transmission - value is changed bytud_audio_n_fb_set() in the meantime or the old value gets sent
return audiod_fb_send(rhport, &_audiod_fct[func_id]);
return audiod_fb_send(rhport, audio);
}
}
#endif
@@ -1970,6 +2040,111 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
return false;
}
#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
static bool set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, uint32_t mclk_freq)
{
// Check if frame interval is within sane limits
// The interval value n_frames was taken from the descriptors within audiod_set_interface()
// n_frames_min is ceil(2^10 * f_s / f_m) for full speed and ceil(2^13 * f_s / f_m) for high speed
// this lower limit ensures the measures feedback value has sufficient precision
uint32_t const k = (TUSB_SPEED_FULL == tud_speed_get()) ? 10 : 13;
uint32_t const n_frame = (1UL << audio->feedback.frame_shift);
if ( (((1UL << k) * sample_freq / mclk_freq) + 1) > n_frame )
{
TU_LOG1(" UAC2 feedback interval too small\r\n"); TU_BREAKPOINT(); return false;
}
// Check if parameters really allow for a power of two division
if ((mclk_freq % sample_freq) == 0 && tu_is_power_of_two(mclk_freq / sample_freq))
{
audio->feedback.compute_method = AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2;
audio->feedback.compute.power_of_2 = 16 - audio->feedback.frame_shift - tu_log2(mclk_freq / sample_freq);
}
else if ( audio->feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT)
{
audio->feedback.compute.float_const = (float)sample_freq / mclk_freq * (1UL << (16 - audio->feedback.frame_shift));
}
else
{
audio->feedback.compute.fixed.sample_freq = sample_freq;
audio->feedback.compute.fixed.mclk_freq = mclk_freq;
}
return true;
}
uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles)
{
audiod_function_t* audio = &_audiod_fct[func_id];
uint32_t feedback;
switch (audio->feedback.compute_method)
{
case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
feedback = (cycles << audio->feedback.compute.power_of_2);
break;
case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
feedback = (uint32_t) ((float) cycles * audio->feedback.compute.float_const);
break;
case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
{
uint64_t fb64 = (((uint64_t) cycles) * audio->feedback.compute.fixed.sample_freq) << (16 - audio->feedback.frame_shift);
feedback = (uint32_t) (fb64 / audio->feedback.compute.fixed.mclk_freq);
}
break;
default: return 0;
}
// For Windows: https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers
// The size of isochronous packets created by the device must be within the limits specified in FMT-2.0 section 2.3.1.1.
// This means that the deviation of actual packet size from nominal size must not exceed +/- one audio slot
// (audio slot = channel count samples).
if ( feedback > audio->feedback.max_value ) feedback = audio->feedback.max_value;
if ( feedback < audio->feedback.min_value ) feedback = audio->feedback.min_value;
tud_audio_n_fb_set(func_id, feedback);
return feedback;
}
#endif
void audiod_sof_isr (uint8_t rhport, uint32_t frame_count)
{
(void) rhport;
(void) frame_count;
#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
// Determine feedback value - The feedback method is described in 5.12.4.2 of the USB 2.0 spec
// Boiled down, the feedback value Ff = n_samples / (micro)frame.
// Since an accuracy of less than 1 Sample / second is desired, at least n_frames = ceil(2^K * f_s / f_m) frames need to be measured, where K = 10 for full speed and K = 13 for high speed, f_s is the sampling frequency e.g. 48 kHz and f_m is the cpu clock frequency e.g. 100 MHz (or any other master clock whose clock count is available and locked to f_s)
// The update interval in the (4.10.2.1) Feedback Endpoint Descriptor must be less or equal to 2^(K - P), where P = min( ceil(log2(f_m / f_s)), K)
// feedback = n_cycles / n_frames * f_s / f_m in 16.16 format, where n_cycles are the number of main clock cycles within fb_n_frames
// Iterate over audio functions and set feedback value
for(uint8_t i=0; i < CFG_TUD_AUDIO; i++)
{
audiod_function_t* audio = &_audiod_fct[i];
if (audio->ep_fb != 0)
{
// HS shift need to be adjusted since SOF event is generated for frame only
uint8_t const hs_adjust = (TUSB_SPEED_HIGH == tud_speed_get()) ? 3 : 0;
uint32_t const interval = 1UL << (audio->feedback.frame_shift - hs_adjust);
if ( 0 == (frame_count & (interval-1)) )
{
if(tud_audio_feedback_interval_isr) tud_audio_feedback_interval_isr(i, frame_count, audio->feedback.frame_shift);
}
}
}
#endif // CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
}
bool tud_audio_buffer_and_schedule_control_xfer(uint8_t rhport, tusb_control_request_t const * p_request, void* data, uint16_t len)
{
// Handles only sending of data not receiving
@@ -2164,6 +2339,16 @@ static bool audiod_verify_ep_exists(uint8_t ep, uint8_t *func_id)
// Currently, only AS interfaces with an EP (in or out) are supposed to be parsed for!
static void audiod_parse_for_AS_params(audiod_function_t* audio, uint8_t const * p_desc, uint8_t const * p_desc_end, uint8_t const as_itf)
{
#if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_in_as_intf_num && as_itf != audio->ep_out_as_intf_num) return; // Abort, this interface has no EP, this driver does not support this currently
#endif
#if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_in_as_intf_num) return;
#endif
#if !CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_out_as_intf_num) return;
#endif
p_desc = tu_desc_next(p_desc); // Exclude standard AS interface descriptor of current alternate interface descriptor
while (p_desc < p_desc_end)
@@ -2174,16 +2359,6 @@ static void audiod_parse_for_AS_params(audiod_function_t* audio, uint8_t const *
// Look for a Class-Specific AS Interface Descriptor(4.9.2) to verify format type and format and also to get number of physical channels
if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO_CS_AS_INTERFACE_AS_GENERAL)
{
#if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_in_as_intf_num && as_itf != audio->ep_out_as_intf_num) break; // Abort loop, this interface has no EP, this driver does not support this currently
#endif
#if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_in_as_intf_num) break;
#endif
#if !CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_EP_OUT
if (as_itf != audio->ep_out_as_intf_num) break;
#endif
#if CFG_TUD_AUDIO_ENABLE_EP_IN
if (as_itf == audio->ep_in_as_intf_num)
{
@@ -2255,7 +2430,7 @@ bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback)
#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION
if ( TUSB_SPEED_FULL == tud_speed_get() )
{
uint8_t * fb = (uint8_t *) &_audiod_fct[func_id].fb_val;
uint8_t * fb = (uint8_t *) &_audiod_fct[func_id].feedback.value;
// For FS format is 10.14
*(fb++) = (feedback >> 2) & 0xFF;
@@ -2267,7 +2442,7 @@ bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback)
#else
{
// Send value as-is, caller will choose the appropriate format
_audiod_fct[func_id].fb_val = feedback;
_audiod_fct[func_id].feedback.value = feedback;
}
#endif

64
src/class/audio/audio_device.h
View File

@@ -458,7 +458,14 @@ TU_ATTR_WEAK bool tud_audio_rx_done_post_read_cb(uint8_t rhport, uint16_t n_byte
#endif
#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
TU_ATTR_WEAK bool tud_audio_fb_done_cb(uint8_t rhport);
TU_ATTR_WEAK void tud_audio_fb_done_cb(uint8_t func_id);
// determined by the user itself and set by use of tud_audio_n_fb_set(). The feedback value may be determined e.g. from some fill status of some FIFO buffer. Advantage: No ISR interrupt is enabled, hence the CPU need not to handle an ISR every 1ms or 125us and thus less CPU load, disadvantage: typically a larger FIFO is needed to compensate for jitter (e.g. 8 frames), i.e. a larger delay is introduced.
// Feedback value is calculated within the audio driver by use of SOF interrupt. The driver needs information about the master clock f_m from which the audio sample frequency f_s is derived, f_s itself, and the cycle count of f_m at time of the SOF interrupt (e.g. by use of a hardware counter) - see tud_audio_set_fb_params(). Advantage: Reduced jitter in the feedback value computation, hence, the receive FIFO can be smaller (e.g. 2 frames) and thus a smaller delay is possible, disadvantage: higher CPU load due to SOF ISR handling every frame i.e. 1ms or 125us. This option is a great starting point to try the SOF ISR option but depending on your hardware setup (performance of the CPU) it might not work. If so, figure out why and use the next option. (The most critical point is the reading of the cycle counter value of f_m. It is read from within the SOF ISR - see: audiod_sof() -, hence, the ISR must has a high priority such that no software dependent "random" delay i.e. jitter is introduced).
// Feedback value is determined by the user by use of SOF interrupt. The user may use tud_audio_sof_isr() which is called every SOF (of course only invoked when an alternate interface other than zero was set). The number of frames used to determine the feedback value for the currently active alternate setting can be get by tud_audio_get_fb_n_frames(). The feedback value must be set by use of tud_audio_n_fb_set().
// This function is used to provide data rate feedback from an asynchronous sink. Feedback value will be sent at FB endpoint interval till it's changed.
//
@@ -468,9 +475,61 @@ TU_ATTR_WEAK bool tud_audio_fb_done_cb(uint8_t rhport);
//
// Note that due to a bug in its USB Audio 2.0 driver, Windows currently requires 16.16 format for _all_ USB 2.0 devices. On Linux and macOS it seems the
// driver can work with either format. So a good compromise is to keep format correction disabled and stick to 16.16 format.
// Feedback value can be determined from within the SOF ISR of the audio driver. This should reduce jitter. If the feature is used, the user can not set the feedback value.
// Determine feedback value - The feedback method is described in 5.12.4.2 of the USB 2.0 spec
// Boiled down, the feedback value Ff = n_samples / (micro)frame.
// Since an accuracy of less than 1 Sample / second is desired, at least n_frames = ceil(2^K * f_s / f_m) frames need to be measured, where K = 10 for full speed and K = 13 for high speed, f_s is the sampling frequency e.g. 48 kHz and f_m is the cpu clock frequency e.g. 100 MHz (or any other master clock whose clock count is available and locked to f_s)
// The update interval in the (4.10.2.1) Feedback Endpoint Descriptor must be less or equal to 2^(K - P), where P = min( ceil(log2(f_m / f_s)), K)
// feedback = n_cycles / n_frames * f_s / f_m in 16.16 format, where n_cycles are the number of main clock cycles within fb_n_frames
bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback);
static inline bool tud_audio_fb_set(uint32_t feedback);
// Update feedback value with passed cycles since last time this update function is called.
// Typically called within tud_audio_sof_isr(). Required tud_audio_feedback_params_cb() is implemented
// This function will also call tud_audio_feedback_set()
// return feedback value in 16.16 for reference (0 for error)
uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles);
enum {
AUDIO_FEEDBACK_METHOD_DISABLED,
AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED,
AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT,
AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2,
// impelemnt later
// AUDIO_FEEDBACK_METHOD_FIFO_COUNT
};
typedef struct {
uint8_t method;
uint32_t sample_freq; // sample frequency in Hz
union {
struct {
uint32_t mclk_freq; // Main clock frequency in Hz i.e. master clock to which sample clock is based on
}frequency;
#if 0 // implement later
struct {
uint32_t threshold_bytes; // minimum number of bytes received to be considered as filled/ready
}fifo_count;
#endif
};
}audio_feedback_params_t;
// Invoked when needed to set feedback parameters
TU_ATTR_WEAK void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param);
// Callback in ISR context, invoked periodically according to feedback endpoint bInterval.
// Could be used to compute and update feedback value
// frame_number : current SOF count
// interval_shift: number of bit shift i.e log2(interval) from Feedback endpoint descriptor
TU_ATTR_WEAK void tud_audio_feedback_interval_isr(uint8_t func_id, uint32_t frame_number, uint8_t interval_shift);
#endif // CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
#if CFG_TUD_AUDIO_INT_CTR_EPSIZE_IN
TU_ATTR_WEAK bool tud_audio_int_ctr_done_cb(uint8_t rhport, uint16_t n_bytes_copied);
@@ -612,10 +671,12 @@ static inline uint16_t tud_audio_int_ctr_write(uint8_t const* buffer, uint16_t l
#endif
#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
static inline bool tud_audio_fb_set(uint32_t feedback)
{
return tud_audio_n_fb_set(0, feedback);
}
#endif
//--------------------------------------------------------------------+
@@ -626,6 +687,7 @@ void audiod_reset (uint8_t rhport);
uint16_t audiod_open (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
bool audiod_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
bool audiod_xfer_cb (uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint32_t xferred_bytes);
void audiod_sof_isr (uint8_t rhport, uint32_t frame_count);
#ifdef __cplusplus
}