--- /dev/null
+/* Teensyduino Core Library
+ * http://www.pjrc.com/teensy/
+ * Copyright (c) 2013 PJRC.COM, LLC.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * 2. If the Software is incorporated into a build system that allows
+ * selection among a list of target devices, then similar target
+ * devices manufactured by PJRC.COM must be included in the list of
+ * target devices and selectable in the same manner.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#if F_CPU >= 20000000
+
+#include "usb_dev.h"
+#include "usb_seremu.h"
+#include "core_pins.h" // for yield()
+//#include "HardwareSerial.h"
+
+#ifdef SEREMU_INTERFACE // defined by usb_dev.h -> usb_desc.h
+
+volatile uint8_t usb_seremu_transmit_flush_timer=0;
+
+static usb_packet_t *rx_packet=NULL;
+static usb_packet_t *tx_packet=NULL;
+static volatile uint8_t tx_noautoflush=0;
+
+#define TRANSMIT_FLUSH_TIMEOUT 5 /* in milliseconds */
+
+
+// get the next character, or -1 if nothing received
+int usb_seremu_getchar(void)
+{
+ unsigned int i;
+ int c;
+
+ while (1) {
+ if (!usb_configuration) return -1;
+ if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
+ if (!rx_packet) return -1;
+ i = rx_packet->index;
+ c = rx_packet->buf[i++];
+ if (c) {
+ if (i >= rx_packet->len) {
+ usb_free(rx_packet);
+ rx_packet = NULL;
+ } else {
+ rx_packet->index = i;
+ }
+ return c;
+ }
+ usb_free(rx_packet);
+ rx_packet = NULL;
+ }
+}
+
+// peek at the next character, or -1 if nothing received
+int usb_seremu_peekchar(void)
+{
+ int c;
+
+ while (1) {
+ if (!usb_configuration) return -1;
+ if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
+ if (!rx_packet) return -1;
+ c = rx_packet->buf[rx_packet->index];
+ if (c) return c;
+ usb_free(rx_packet);
+ rx_packet = NULL;
+ }
+}
+
+// number of bytes available in the receive buffer
+int usb_seremu_available(void)
+{
+ int i, len, count;
+
+ if (!rx_packet) {
+ if (usb_configuration) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
+ if (!rx_packet) return 0;
+ }
+ len = rx_packet->len;
+ i = rx_packet->index;
+ count = 0;
+ for (i = rx_packet->index; i < len; i++) {
+ if (rx_packet->buf[i] == 0) break;
+ count++;
+ }
+ if (count == 0) {
+ usb_free(rx_packet);
+ rx_packet = NULL;
+ }
+ return count;
+}
+
+
+// discard any buffered input
+void usb_seremu_flush_input(void)
+{
+ usb_packet_t *rx;
+
+ if (!usb_configuration) return;
+ if (rx_packet) {
+ usb_free(rx_packet);
+ rx_packet = NULL;
+ }
+ while (1) {
+ rx = usb_rx(SEREMU_RX_ENDPOINT);
+ if (!rx) break;
+ usb_free(rx);
+ }
+}
+
+
+
+// Maximum number of transmit packets to queue so we don't starve other endpoints for memory
+#define TX_PACKET_LIMIT 6
+
+// When the PC isn't listening, how long do we wait before discarding data? If this is
+// too short, we risk losing data during the stalls that are common with ordinary desktop
+// software. If it's too long, we stall the user's program when no software is running.
+#define TX_TIMEOUT_MSEC 30
+
+#if F_CPU == 168000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 1100)
+#elif F_CPU == 144000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 932)
+#elif F_CPU == 120000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 764)
+#elif F_CPU == 96000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
+#elif F_CPU == 72000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 512)
+#elif F_CPU == 48000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
+#elif F_CPU == 24000000
+ #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
+#endif
+
+
+// When we've suffered the transmit timeout, don't wait again until the computer
+// begins accepting data. If no software is running to receive, we'll just discard
+// data as rapidly as Serial.print() can generate it, until there's something to
+// actually receive it.
+static uint8_t transmit_previous_timeout=0;
+
+
+// transmit a character. 0 returned on success, -1 on error
+int usb_seremu_putchar(uint8_t c)
+{
+ return usb_seremu_write(&c, 1);
+}
+
+
+int usb_seremu_write(const void *buffer, uint32_t size)
+{
+#if 1
+ uint32_t len;
+ uint32_t wait_count;
+ const uint8_t *src = (const uint8_t *)buffer;
+ uint8_t *dest;
+
+ tx_noautoflush = 1;
+ while (size > 0) {
+ if (!tx_packet) {
+ wait_count = 0;
+ while (1) {
+ if (!usb_configuration) {
+ tx_noautoflush = 0;
+ return -1;
+ }
+ if (usb_tx_packet_count(SEREMU_TX_ENDPOINT) < TX_PACKET_LIMIT) {
+ tx_noautoflush = 1;
+ tx_packet = usb_malloc();
+ if (tx_packet) break;
+ }
+ if (++wait_count > TX_TIMEOUT || transmit_previous_timeout) {
+ transmit_previous_timeout = 1;
+ tx_noautoflush = 0;
+ return -1;
+ }
+ tx_noautoflush = 0;
+ yield();
+ tx_noautoflush = 1;
+ }
+ }
+ transmit_previous_timeout = 0;
+ len = SEREMU_TX_SIZE - tx_packet->index;
+ if (len > size) len = size;
+ dest = tx_packet->buf + tx_packet->index;
+ tx_packet->index += len;
+ size -= len;
+ while (len-- > 0) *dest++ = *src++;
+ if (tx_packet->index < SEREMU_TX_SIZE) {
+ usb_seremu_transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
+ } else {
+ tx_packet->len = SEREMU_TX_SIZE;
+ usb_seremu_transmit_flush_timer = 0;
+ usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
+ tx_packet = NULL;
+ }
+ }
+ tx_noautoflush = 0;
+ return 0;
+#endif
+}
+
+int usb_seremu_write_buffer_free(void)
+{
+ uint32_t len;
+
+ tx_noautoflush = 1;
+ if (!tx_packet) {
+ if (!usb_configuration ||
+ usb_tx_packet_count(SEREMU_TX_ENDPOINT) >= TX_PACKET_LIMIT ||
+ (tx_packet = usb_malloc()) == NULL) {
+ tx_noautoflush = 0;
+ return 0;
+ }
+ }
+ len = SEREMU_TX_SIZE - tx_packet->index;
+ tx_noautoflush = 0;
+ return len;
+}
+
+void usb_seremu_flush_output(void)
+{
+ int i;
+
+ if (!usb_configuration) return;
+ //serial_print("usb_serial_flush_output\n");
+ if (tx_packet && tx_packet->index > 0) {
+ usb_seremu_transmit_flush_timer = 0;
+ for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
+ tx_packet->buf[i] = 0;
+ }
+ tx_packet->len = SEREMU_TX_SIZE;
+ usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
+ tx_packet = NULL;
+ }
+ // while (usb_tx_byte_count(SEREMU_TX_ENDPOINT) > 0) ; // wait
+}
+
+void usb_seremu_flush_callback(void)
+{
+ int i;
+ //serial_print("C");
+ if (tx_noautoflush) return;
+ //serial_print("usb_flush_callback \n");
+ for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
+ tx_packet->buf[i] = 0;
+ }
+ tx_packet->len = SEREMU_TX_SIZE;
+ usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
+ tx_packet = NULL;
+ //serial_print("usb_flush_callback end\n");
+}
+
+#endif // SEREMU_INTERFACE
+
+#endif // F_CPU >= 20 MHz
notaz.gp2x.de / megadrive.git / blobdiff