summaryrefslogtreecommitdiff
path: root/usb_debug.c
diff options
context:
space:
mode:
authortmk2010-09-23 20:23:50 +0900
committertmk2010-09-23 20:23:50 +0900
commit7fd9003f59ad6a1de8d8b70fae74ba16df666c09 (patch)
tree965fa71209fbb0a947aa9848ab9dba2247d9b5b9 /usb_debug.c
parent6be0e4fafb3875264317f048b2c823dea87a9f49 (diff)
divide usb_keyboard_debug.[c|h] into usb_device, usb_keyboard, usb_debug.
Diffstat (limited to 'usb_debug.c')
-rw-r--r--usb_debug.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/usb_debug.c b/usb_debug.c
new file mode 100644
index 000000000..97590184a
--- /dev/null
+++ b/usb_debug.c
@@ -0,0 +1,80 @@
+#include <avr/interrupt.h>
+#include "usb_debug.h"
+
+
+// the time remaining before we transmit any partially full
+// packet, or send a zero length packet.
+volatile uint8_t debug_flush_timer=0;
+
+
+// transmit a character. 0 returned on success, -1 on error
+int8_t usb_debug_putchar(uint8_t c)
+{
+ static uint8_t previous_timeout=0;
+ uint8_t timeout, intr_state;
+
+ // if we're not online (enumerated and configured), error
+ if (!usb_configured()) return -1;
+ // interrupts are disabled so these functions can be
+ // used from the main program or interrupt context,
+ // even both in the same program!
+ intr_state = SREG;
+ cli();
+ UENUM = DEBUG_TX_ENDPOINT;
+ // if we gave up due to timeout before, don't wait again
+ if (previous_timeout) {
+ if (!(UEINTX & (1<<RWAL))) {
+ SREG = intr_state;
+ return -1;
+ }
+ previous_timeout = 0;
+ }
+ // wait for the FIFO to be ready to accept data
+ timeout = UDFNUML + 4;
+ while (1) {
+ // are we ready to transmit?
+ if (UEINTX & (1<<RWAL)) break;
+ SREG = intr_state;
+ // have we waited too long?
+ if (UDFNUML == timeout) {
+ previous_timeout = 1;
+ return -1;
+ }
+ // has the USB gone offline?
+ if (!usb_configured()) return -1;
+ // get ready to try checking again
+ intr_state = SREG;
+ cli();
+ UENUM = DEBUG_TX_ENDPOINT;
+ }
+ // actually write the byte into the FIFO
+ UEDATX = c;
+ // if this completed a packet, transmit it now!
+ if (!(UEINTX & (1<<RWAL))) {
+ UEINTX = 0x3A;
+ debug_flush_timer = 0;
+ } else {
+ debug_flush_timer = 2;
+ }
+ SREG = intr_state;
+ return 0;
+}
+
+
+// immediately transmit any buffered output.
+void usb_debug_flush_output(void)
+{
+ uint8_t intr_state;
+
+ intr_state = SREG;
+ cli();
+ if (debug_flush_timer) {
+ UENUM = DEBUG_TX_ENDPOINT;
+ while ((UEINTX & (1<<RWAL))) {
+ UEDATX = 0;
+ }
+ UEINTX = 0x3A;
+ debug_flush_timer = 0;
+ }
+ SREG = intr_state;
+}