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atmel-samd: Use our own CDC output cache because the internal (#366) 

atmel-samd: Use our own CDC output cache because the internal
cache is only used when the memory isn't aligned even if we're
going to change the memory immediately after.
This commit is contained in:
Scott Shawcroft 2017-10-24 12:57:03 -07:00 committed by GitHub
parent ee1092fcaf
commit d43564f854
1 changed files with 35 additions and 10 deletions
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45
atmel-samd/usb.c
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@ -65,6 +65,7 @@ static volatile uint8_t usb_rx_buf_tail;
volatile uint8_t usb_rx_count;
volatile bool mp_cdc_enabled = false;
volatile bool usb_transmitting = false;
static uint8_t multi_desc_bytes[] = {
/* Device descriptors and Configuration descriptors list. */
@ -161,9 +162,14 @@ static bool read_complete(const uint8_t ep, const enum usb_xfer_code rc, const u
return false;
}
static bool write_complete(const uint8_t ep, const enum usb_xfer_code rc, const uint32_t count)
{
// This is called after writed are finished.
static bool write_complete(const uint8_t ep,
const enum usb_xfer_code rc,
const uint32_t count) {
if (rc != USB_XFER_DONE) {
return false; // No errors.
}
// This is called after writes are finished.
usb_transmitting = false;
/* No error. */
return false;
}
@ -267,18 +273,37 @@ int usb_read(void) {
return data;
}
// TODO(tannewt): See if we can disable the internal CDC IN cache since we
// we manage this one ourselves.
#define CDC_BULKIN_SIZE CONF_USB_COMPOSITE_CDC_ACM_DATA_BULKIN_MAXPKSZ
COMPILER_ALIGNED(4) uint8_t cdc_output_buffer[CDC_BULKIN_SIZE];
void usb_write(const char* buffer, uint32_t len) {
if (!cdc_enabled()) {
return;
}
int32_t result = cdcdf_acm_write((uint8_t *)buffer, len);
while (result == USB_BUSY) {
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
result = cdcdf_acm_write((uint8_t *)buffer, len);
uint8_t * output_buffer;
uint8_t output_len;
while (len > 0) {
while (usb_transmitting) {}
output_buffer = (uint8_t *) buffer;
output_len = len;
// Use our own cache in two different cases:
// * When we're at the end of a transmission and we'll return before
// the given buffer is actually transferred to the USB device.
// * When our given buffer isn't aligned on word boundaries.
if (output_len <= CDC_BULKIN_SIZE || ((uint32_t) buffer) % 4 != 0) {
output_buffer = cdc_output_buffer;
output_len = output_len > CDC_BULKIN_SIZE ? CDC_BULKIN_SIZE : output_len;
memcpy(cdc_output_buffer, buffer, output_len);
} else {
output_len = CDC_BULKIN_SIZE;
}
usb_transmitting = true;
cdcdf_acm_write(output_buffer, output_len);
buffer += output_len * sizeof(char);
len -= output_len;
}
while (result != ERR_NONE) {}
}
bool usb_connected(void) {