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change tud_descriptor_string_cb() to be consistent with other descriptor callback

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This commit is contained in:
hathach
2019-05-12 15:38:15 +07:00
parent ba2136486c
commit 1174949308
8 changed files with 90 additions and 74 deletions
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32
examples/device/hid_generic_inout/src/usb_descriptors.c
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@@ -123,30 +123,36 @@ char const* string_desc_arr [] =
"123456", // 3: Serials, should use chip ID
};
// Invoked when received GET_STRING_DESC request
// max_char is CFG_TUD_ENDOINT0_SIZE/2 -1, typically max_char = 31 if Endpoint0 size is 64
// Return number of characters. Note usb string is in 16-bits unicode format
uint8_t tud_descriptor_string_cb(uint8_t index, uint16_t* desc, uint8_t max_char)
static uint16_t _desc_str[32];
// Invoked when received GET STRING DESCRIPTOR request
// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
uint16_t const* tud_descriptor_string_cb(uint8_t index)
{
uint8_t chr_count;
if ( index == 0)
{
memcpy(desc, string_desc_arr[0], 2);
return 1;
memcpy(&_desc_str[1], string_desc_arr[0], 2);
chr_count = 1;
}else
{
if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return 0;
if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
const char* str = string_desc_arr[index];
// Cap at max char
uint8_t count = strlen(str);
if ( count > max_char ) count = max_char;
chr_count = strlen(str);
if ( chr_count > 31 ) chr_count = 31;
for(uint8_t i=0; i<count; i++)
for(uint8_t i=0; i<chr_count; i++)
{
*desc++ = str[i];
_desc_str[1+i] = str[i];
}
return count;
}
// first byte is len, second byte is string type
_desc_str[0] = TUD_DESC_STR_HEADER(chr_count);
return _desc_str;
}