--- /dev/null
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+#include "ao_usb.h"
+#include "ao_product.h"
+
+#ifndef AO_POWER_MANAGEMENT
+#define AO_POWER_MANAGEMENT 0
+#endif
+
+#ifndef AO_USB_DEVICE_ID_SERIAL
+#define AO_USB_DEVICE_ID_SERIAL 0
+#endif
+
+#if USE_USB_FIFO
+static struct ao_fifo ao_usb_rx_fifo;
+#endif
+
+#define AO_USB_OUT_SLEEP_ADDR (&ao_usb_out_avail)
+
+#define SAMD21_USB_ALIGN __attribute__ ((aligned(4)))
+
+struct ao_usb_setup {
+ uint8_t dir_type_recip;
+ uint8_t request;
+ uint16_t value;
+ uint16_t index;
+ uint16_t length;
+} ao_usb_setup;
+
+static uint8_t ao_usb_ep0_state;
+
+struct samd21_usb_desc samd21_usb_desc[8] SAMD21_USB_ALIGN;
+
+/* Pending EP0 IN data */
+static uint8_t ao_usb_ep0_in_tmp[2]; /* small buffer */
+static const uint8_t *ao_usb_ep0_in_data; /* Remaining data */
+static uint8_t ao_usb_ep0_in_len; /* Remaining amount */
+
+/* Pending EP0 OUT data */
+static uint8_t *ao_usb_ep0_out_data;
+static uint8_t ao_usb_ep0_out_len;
+
+/* Endpoint 0 buffers */
+static uint8_t ao_usb_ep0_in_buf[AO_USB_CONTROL_SIZE] SAMD21_USB_ALIGN;
+static uint8_t ao_usb_ep0_out_buf[AO_USB_CONTROL_SIZE] SAMD21_USB_ALIGN;
+
+#if AO_USB_HAS_INT
+/* Pointer to interrupt buffer in USB memory */
+static uint8_t ao_usb_int_buf[AO_USB_INT_SIZE] SAMD21_USB_ALIGN;
+#endif
+
+/* Buffers in DRAM */
+#if AO_USB_HAS_IN
+static uint8_t ao_usb_in_tx_which;
+static uint8_t ao_usb_tx_count;
+static uint8_t ao_usb_in_buf[2][AO_USB_IN_SIZE] SAMD21_USB_ALIGN;
+
+#endif
+#if AO_USB_HAS_OUT
+static uint8_t ao_usb_out_rx_which;
+#if !USE_USB_FIFO
+static uint8_t ao_usb_rx_count, ao_usb_rx_pos;
+#endif
+static uint8_t ao_usb_out_buf[2][AO_USB_OUT_SIZE] SAMD21_USB_ALIGN;
+
+#endif
+
+/* Marks when we don't need to send an IN packet.
+ * This happens only when the last IN packet is not full,
+ * otherwise the host will expect to keep seeing packets.
+ * Send a zero-length packet as required
+ */
+static uint8_t ao_usb_in_flushed;
+
+/* Marks when we have delivered an IN packet to the hardware
+ * and it has not been received yet. ao_sleep on this address
+ * to wait for it to be delivered.
+ */
+static uint8_t ao_usb_in_pending;
+
+/* Marks when an OUT packet has been received by the hardware
+ * but not pulled to the shadow buffer.
+ */
+static uint8_t ao_usb_out_avail;
+uint8_t ao_usb_running;
+static uint8_t ao_usb_configuration;
+
+#define AO_USB_EP0_GOT_SETUP 1
+#define AO_USB_EP0_GOT_RX_DATA 2
+#define AO_USB_EP0_GOT_TX_ACK 4
+
+static uint8_t ao_usb_ep0_receive;
+static uint8_t ao_usb_address;
+static uint8_t ao_usb_address_pending;
+
+/*
+ * Set current device address and mark the
+ * interface as active
+ */
+static void
+ao_usb_set_address(uint8_t address)
+{
+ samd21_usb.dadd = (1 << SAMD21_USB_DADD_ADDEN) | (address << SAMD21_USB_DADD_DADD);
+ ao_usb_address_pending = 0;
+}
+
+/*
+ * Initialize an entpoint
+ */
+
+static void
+ao_usb_init_bank(struct samd21_usb_desc_bank *bank,
+ uint8_t *buf,
+ uint16_t size)
+{
+ bank->addr = (uint32_t) buf;
+
+ uint32_t size_bits = 0;
+ switch (size) {
+ case 8: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_8; break;
+ case 16: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_16; break;
+ case 32: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_32; break;
+ case 64: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_64; break;
+ case 128: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_128; break;
+ case 256: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_256; break;
+ case 512: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_512; break;
+ case 1023: size_bits = SAMD21_USB_DESC_PCKSIZE_SIZE_1023; break;
+ }
+ bank->pcksize = ((0 << SAMD21_USB_DESC_PCKSIZE_BYTE_COUNT) |
+ (0 << SAMD21_USB_DESC_PCKSIZE_MULTI_PACKET_SIZE) |
+ (size_bits << SAMD21_USB_DESC_PCKSIZE_SIZE) |
+ (0 << SAMD21_USB_DESC_PCKSIZE_AUTO_ZLP));
+}
+
+static void
+ao_usb_init_ep(uint8_t ep,
+ uint8_t type_out, void *out_buf, uint16_t out_size,
+ uint8_t type_in, void *in_buf, uint16_t in_size)
+{
+ /* set up descriptors */
+ ao_usb_init_bank(&samd21_usb_desc[ep].bank[0],
+ out_buf, out_size);
+
+ ao_usb_init_bank(&samd21_usb_desc[ep].bank[1],
+ in_buf, in_size);
+
+ samd21_usb.ep[ep].epcfg = (uint8_t) ((type_out << SAMD21_USB_EP_EPCFG_EP_TYPE_OUT) |
+ (type_in << SAMD21_USB_EP_EPCFG_EP_TYPE_IN));
+
+ /* Clear all status bits */
+ samd21_usb.ep[ep].epstatusclr = 0xff;
+
+ /* Select interrupts */
+ uint8_t epinten = 0;
+ if (out_buf)
+ epinten |= (1 << SAMD21_USB_EP_EPINTFLAG_TRCPT0);
+ if (in_buf)
+ epinten |= (1 << SAMD21_USB_EP_EPINTFLAG_TRCPT1);
+ if (ep == 0)
+ epinten |= (1 << SAMD21_USB_EP_EPINTFLAG_RXSTP);
+ samd21_usb.ep[ep].epintenset = epinten;
+}
+
+static void
+ao_usb_set_ep0(void)
+{
+ ao_usb_init_ep(AO_USB_CONTROL_EP,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_OUT_CONTROL,
+ ao_usb_ep0_out_buf, AO_USB_CONTROL_SIZE,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_IN_CONTROL,
+ ao_usb_ep0_in_buf, AO_USB_CONTROL_SIZE);
+
+ ao_usb_running = 0;
+
+ /* Reset our internal state
+ */
+
+ ao_usb_ep0_state = AO_USB_EP0_IDLE;
+
+ ao_usb_ep0_in_data = NULL;
+ ao_usb_ep0_in_len = 0;
+
+ ao_usb_ep0_out_data = NULL;
+ ao_usb_ep0_out_len = 0;
+}
+
+static void
+ao_usb_set_configuration(void)
+{
+#if AO_USB_HAS_INT
+ ao_usb_init_ep(AO_USB_INT_EP,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_OUT_DISABLED,
+ NULL, 0,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_IN_INTERRUPT,
+ ao_usb_int_buf, AO_USB_INT_SIZE);
+#endif
+
+#if AO_USB_HAS_OUT
+ ao_usb_init_ep(AO_USB_OUT_EP,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_OUT_BULK,
+ &ao_usb_out_buf[0][0], AO_USB_OUT_SIZE,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_IN_DUAL_BANK,
+ &ao_usb_out_buf[1][0], AO_USB_OUT_SIZE);
+
+ /* At first receive, we'll flip this back to 0 */
+ ao_usb_out_rx_which = 1;
+#endif
+
+#if AO_USB_HAS_IN
+ /* Set up the IN end point */
+ ao_usb_init_ep(AO_USB_IN_EP,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_OUT_DUAL_BANK,
+ &ao_usb_in_buf[0][0], AO_USB_IN_SIZE,
+ SAMD21_USB_EP_EPCFG_EP_TYPE_IN_BULK,
+ &ao_usb_in_buf[1][0], AO_USB_IN_SIZE);
+
+ /* First transmit data goes to buffer 0 */
+ ao_usb_in_tx_which = 0;
+#endif
+
+ ao_usb_in_flushed = 1;
+ ao_usb_in_pending = 0;
+ ao_wakeup(&ao_usb_in_pending);
+
+ ao_usb_out_avail = 0;
+ ao_usb_configuration = 0;
+
+ ao_wakeup(AO_USB_OUT_SLEEP_ADDR);
+}
+
+/* Send an IN data packet */
+static void
+ao_usb_ep0_flush(void)
+{
+ uint8_t this_len;
+
+ /* Check to see if the endpoint is still busy */
+ if ((samd21_usb.ep[0].epstatus & (1 << (SAMD21_USB_EP_EPSTATUS_BK1RDY))) != 0)
+ return;
+
+ this_len = ao_usb_ep0_in_len;
+ if (this_len > AO_USB_CONTROL_SIZE)
+ this_len = AO_USB_CONTROL_SIZE;
+
+ if (this_len < AO_USB_CONTROL_SIZE)
+ ao_usb_ep0_state = AO_USB_EP0_IDLE;
+
+ ao_usb_ep0_in_len -= this_len;
+
+ memcpy(ao_usb_ep0_in_buf, ao_usb_ep0_in_data, this_len);
+ ao_usb_ep0_in_data += this_len;
+
+ /* Mark the endpoint as TX valid to send the packet */
+ samd21_usb_desc_set_byte_count(AO_USB_CONTROL_EP, 1, this_len);
+ samd21_usb_ep_set_ready(AO_USB_CONTROL_EP, 1);
+}
+
+/* Read data from the ep0 OUT fifo */
+static void
+ao_usb_ep0_fill(void)
+{
+ uint16_t len = samd21_usb_desc_get_byte_count(AO_USB_CONTROL_EP, 0);
+
+ if (len > ao_usb_ep0_out_len)
+ len = ao_usb_ep0_out_len;
+ ao_usb_ep0_out_len -= (uint8_t) len;
+
+ /* Pull all of the data out of the packet */
+ memcpy(ao_usb_ep0_out_data, ao_usb_ep0_out_buf, len);
+ ao_usb_ep0_out_data += len;
+
+ /* ACK the packet */
+ samd21_usb_ep_clr_ready(AO_USB_CONTROL_EP, 0);
+}
+
+static void
+ao_usb_ep0_in_reset(void)
+{
+ ao_usb_ep0_in_data = ao_usb_ep0_in_tmp;
+ ao_usb_ep0_in_len = 0;
+}
+
+static void
+ao_usb_ep0_in_queue_byte(uint8_t a)
+{
+ if (ao_usb_ep0_in_len < sizeof (ao_usb_ep0_in_tmp))
+ ao_usb_ep0_in_tmp[ao_usb_ep0_in_len++] = a;
+}
+
+static void
+ao_usb_ep0_in_set(const uint8_t *data, uint8_t len)
+{
+ ao_usb_ep0_in_data = data;
+ ao_usb_ep0_in_len = len;
+}
+
+static void
+ao_usb_ep0_out_set(uint8_t *data, uint8_t len)
+{
+ ao_usb_ep0_out_data = data;
+ ao_usb_ep0_out_len = len;
+}
+
+static void
+ao_usb_ep0_in_start(uint16_t max)
+{
+ /* Don't send more than asked for */
+ if (ao_usb_ep0_in_len > max)
+ ao_usb_ep0_in_len = (uint8_t) max;
+ ao_usb_ep0_flush();
+}
+
+struct ao_usb_line_coding ao_usb_line_coding = {115200, 0, 0, 8};
+
+#if AO_USB_DEVICE_ID_SERIAL
+static uint8_t ao_usb_serial[2 + 64];
+
+/* Convert a 32-bit value to 8 hexidecimal UCS2 characters */
+static void
+hex_to_ucs2(uint32_t in, uint8_t *out)
+{
+ int i;
+
+ for (i = 28; i >= 0; i -= 4) {
+ uint8_t bits = (in >> i) & 0xf;
+ *out++ = ((bits < 10) ? '0' : ('a' - 10)) + bits;
+ *out++ = 0;
+ }
+}
+
+/* Encode the device ID (128 bits) in hexidecimal to use as a device
+ * serial number
+ */
+static void
+ao_usb_serial_init(void)
+{
+ ao_usb_serial[0] = 66; /* length */
+ ao_usb_serial[1] = AO_USB_DESC_STRING;
+ hex_to_ucs2(samd21_serial.word0, ao_usb_serial + 2 + 0);
+ hex_to_ucs2(samd21_serial.word1, ao_usb_serial + 2 + 16);
+ hex_to_ucs2(samd21_serial.word2, ao_usb_serial + 2 + 32);
+ hex_to_ucs2(samd21_serial.word3, ao_usb_serial + 2 + 48);
+}
+#endif
+
+/* Walk through the list of descriptors and find a match
+ */
+static void
+ao_usb_get_descriptor(uint16_t value, uint16_t length)
+{
+ const uint8_t *descriptor;
+ uint8_t type = (uint8_t) (value >> 8);
+ uint8_t index = (uint8_t) value;
+
+ descriptor = ao_usb_descriptors;
+ while (descriptor[0] != 0) {
+ if (descriptor[1] == type && index-- == 0) {
+ uint8_t len;
+ if (type == AO_USB_DESC_CONFIGURATION)
+ len = descriptor[2];
+ else
+ len = descriptor[0];
+#if AO_USB_DEVICE_ID_SERIAL
+ /* Slightly hacky - the serial number is string 3 */
+ if (type == AO_USB_DESC_STRING && (value & 0xff) == 3) {
+ descriptor = ao_usb_serial;
+ len = sizeof (ao_usb_serial);
+ }
+#endif
+ if (len > length)
+ len = (uint8_t) length;
+ ao_usb_ep0_in_set(descriptor, len);
+ break;
+ }
+ descriptor += descriptor[0];
+ }
+}
+
+static void
+ao_usb_ep0_setup(void)
+{
+ /* Pull the setup packet out of the fifo */
+ ao_usb_ep0_out_set((uint8_t *) &ao_usb_setup, 8);
+ ao_usb_ep0_fill();
+ if (ao_usb_ep0_out_len != 0)
+ return;
+
+ if ((ao_usb_setup.dir_type_recip & AO_USB_DIR_IN) || ao_usb_setup.length == 0)
+ ao_usb_ep0_state = AO_USB_EP0_DATA_IN;
+ else
+ ao_usb_ep0_state = AO_USB_EP0_DATA_OUT;
+
+ ao_usb_ep0_in_reset();
+
+ switch(ao_usb_setup.dir_type_recip & AO_USB_SETUP_TYPE_MASK) {
+ case AO_USB_TYPE_STANDARD:
+ switch(ao_usb_setup.dir_type_recip & AO_USB_SETUP_RECIP_MASK) {
+ case AO_USB_RECIP_DEVICE:
+ switch(ao_usb_setup.request) {
+ case AO_USB_REQ_GET_STATUS:
+ ao_usb_ep0_in_queue_byte(0);
+ ao_usb_ep0_in_queue_byte(0);
+ break;
+ case AO_USB_REQ_SET_ADDRESS:
+ ao_usb_address = (uint8_t) ao_usb_setup.value;
+ ao_usb_address_pending = 1;
+ break;
+ case AO_USB_REQ_GET_DESCRIPTOR:
+ ao_usb_get_descriptor(ao_usb_setup.value, ao_usb_setup.length);
+ break;
+ case AO_USB_REQ_GET_CONFIGURATION:
+ ao_usb_ep0_in_queue_byte(ao_usb_configuration);
+ break;
+ case AO_USB_REQ_SET_CONFIGURATION:
+ ao_usb_configuration = (uint8_t) ao_usb_setup.value;
+ ao_usb_set_configuration();
+ break;
+ }
+ break;
+ case AO_USB_RECIP_INTERFACE:
+ switch(ao_usb_setup.request) {
+ case AO_USB_REQ_GET_STATUS:
+ ao_usb_ep0_in_queue_byte(0);
+ ao_usb_ep0_in_queue_byte(0);
+ break;
+ case AO_USB_REQ_GET_INTERFACE:
+ ao_usb_ep0_in_queue_byte(0);
+ break;
+ case AO_USB_REQ_SET_INTERFACE:
+ break;
+ }
+ break;
+ case AO_USB_RECIP_ENDPOINT:
+ switch(ao_usb_setup.request) {
+ case AO_USB_REQ_GET_STATUS:
+ ao_usb_ep0_in_queue_byte(0);
+ ao_usb_ep0_in_queue_byte(0);
+ break;
+ }
+ break;
+ }
+ break;
+ case AO_USB_TYPE_CLASS:
+ switch (ao_usb_setup.request) {
+ case AO_USB_SET_LINE_CODING:
+ ao_usb_ep0_out_set((uint8_t *) &ao_usb_line_coding, 7);
+ break;
+ case AO_USB_GET_LINE_CODING:
+ ao_usb_ep0_in_set((const uint8_t *) &ao_usb_line_coding, 7);
+ break;
+ case AO_USB_SET_CONTROL_LINE_STATE:
+ break;
+ }
+ break;
+ }
+
+ /* If we're not waiting to receive data from the host,
+ * queue an IN response
+ */
+ if (ao_usb_ep0_state == AO_USB_EP0_DATA_IN)
+ ao_usb_ep0_in_start(ao_usb_setup.length);
+}
+
+static void
+ao_usb_ep0_handle(uint8_t receive)
+{
+ ao_usb_ep0_receive = 0;
+ if (receive & AO_USB_EP0_GOT_SETUP) {
+ ao_usb_ep0_setup();
+ }
+ if (receive & AO_USB_EP0_GOT_RX_DATA) {
+ if (ao_usb_ep0_state == AO_USB_EP0_DATA_OUT) {
+ ao_usb_ep0_fill();
+ if (ao_usb_ep0_out_len == 0) {
+ ao_usb_ep0_state = AO_USB_EP0_DATA_IN;
+ ao_usb_ep0_in_start(0);
+ }
+ }
+ }
+ if (receive & AO_USB_EP0_GOT_TX_ACK) {
+
+#if HAS_FLIGHT && AO_USB_FORCE_IDLE
+ ao_flight_force_idle = 1;
+#endif
+ if (ao_usb_ep0_state == AO_USB_EP0_DATA_IN)
+ ao_usb_ep0_flush();
+ /* Wait until the IN packet is received from addr 0
+ * before assigning our local address
+ */
+ if (ao_usb_address_pending)
+ ao_usb_set_address(ao_usb_address);
+ }
+}
+
+#if AO_POWER_MANAGEMENT
+static void
+ao_usb_suspend(void)
+{
+ stm_usb.cntr |= (1 << STM_USB_CNTR_FSUSP);
+ ao_power_suspend();
+ stm_usb.cntr |= (1 << STM_USB_CNTR_LP_MODE);
+ ao_clock_suspend();
+}
+
+static void
+ao_usb_wakeup(void)
+{
+ ao_clock_resume();
+ stm_usb.cntr &= ~(1 << STM_USB_CNTR_FSUSP);
+ ao_power_resume();
+}
+#endif
+
+#if USE_USB_FIFO
+static void
+ao_usb_fifo_check(void)
+{
+ uint8_t next_which = 1 - ao_usb_out_rx_which;
+ if (ao_usb_out_avail & (1 << next_which)) {
+ uint8_t *buf = ao_usb_out_buf[next_which];
+ uint16_t len = samd21_usb_desc_get_byte_count(AO_USB_OUT_EP, next_which);
+
+ if (ao_fifo_has_space(&ao_usb_rx_fifo, len)) {
+ uint16_t i;
+
+#if AO_USB_OUT_HOOK
+ ao_usb_out_hook(buf, len);
+#endif
+ for (i = 0; i < len; i++)
+ ao_fifo_insert(&ao_usb_rx_fifo, buf[i]);
+ samd21_usb_ep_clr_ready(AO_USB_OUT_EP, next_which);
+ ao_usb_out_avail &= ~(1 << next_which);
+ ao_usb_out_rx_which = next_which;
+ ao_wakeup(AO_USB_OUT_SLEEP_ADDR);
+ }
+ }
+}
+#endif
+
+void
+samd21_usb_isr(void)
+{
+ uint16_t intflag = samd21_usb.intflag;
+ uint16_t epintsmry = samd21_usb.epintsmry;
+
+ samd21_usb.intflag = intflag;
+
+ if (epintsmry & (1 << 0)) {
+ uint8_t epintflag = samd21_usb.ep[0].epintflag;
+ samd21_usb.ep[0].epintflag = epintflag;
+
+ if (epintflag & (1 << SAMD21_USB_EP_EPINTFLAG_RXSTP))
+ ao_usb_ep0_receive |= AO_USB_EP0_GOT_SETUP;
+ else if (epintflag & (1 << SAMD21_USB_EP_EPINTFLAG_TRCPT0))
+ ao_usb_ep0_receive |= AO_USB_EP0_GOT_RX_DATA;
+ if (epintflag & (1 << SAMD21_USB_EP_EPINTFLAG_TRCPT1))
+ ao_usb_ep0_receive |= AO_USB_EP0_GOT_TX_ACK;
+ ao_usb_ep0_handle(ao_usb_ep0_receive);
+ }
+#if AO_USB_HAS_OUT
+ if (epintsmry & (1 << AO_USB_OUT_EP)) {
+ uint8_t epintflag = samd21_usb.ep[AO_USB_OUT_EP].epintflag;
+ samd21_usb.ep[AO_USB_OUT_EP].epintflag = epintflag;
+ uint8_t avail = (epintflag >> SAMD21_USB_EP_EPINTFLAG_TRCPT0) & 3;
+ if (avail) {
+ ao_usb_out_avail |= avail;
+ ao_usb_running = 1;
+#if USE_USB_FIFO
+ ao_usb_fifo_check();
+#else
+ ao_wakeup(AO_USB_OUT_SLEEP_ADDR);
+#endif
+ }
+ }
+#endif
+#if AO_USB_HAS_IN
+ if (epintsmry & (1 << AO_USB_IN_EP)) {
+ uint8_t epintflag = samd21_usb.ep[AO_USB_IN_EP].epintflag;
+ samd21_usb.ep[AO_USB_IN_EP].epintflag = epintflag;
+ uint8_t done = (epintflag >> SAMD21_USB_EP_EPINTFLAG_TRCPT0) & 3;
+ if (done) {
+ ao_usb_in_pending &= (uint8_t) ~done;
+ ao_wakeup(&ao_usb_in_pending);
+ }
+ }
+#endif
+#if AO_USB_HAS_INT
+ if (epintsmry & (1 << AO_USB_INT_EP)) {
+ }
+#endif
+ if (intflag & (1 << SAMD21_USB_INTFLAG_EORST)) {
+ ao_usb_set_ep0();
+ }
+#if AO_POWER_MANAGEMENT
+ if (istr & (1 << STM_USB_ISTR_SUSP))
+ ao_usb_suspend();
+
+ if (istr & (1 << STM_USB_ISTR_WKUP))
+ ao_usb_wakeup();
+#endif
+}
+
+#if AO_USB_HAS_IN
+/* Queue the current IN buffer for transmission */
+static void
+_ao_usb_in_send(void)
+{
+ ao_usb_in_pending |= (uint8_t) (1 << ao_usb_in_tx_which);
+ if (ao_usb_tx_count != AO_USB_IN_SIZE)
+ ao_usb_in_flushed = 1;
+
+ samd21_usb_desc_set_byte_count(AO_USB_IN_EP, ao_usb_in_tx_which, ao_usb_tx_count);
+ samd21_usb_ep_set_ready(AO_USB_IN_EP, ao_usb_in_tx_which);
+
+ /* Toggle our usage */
+ ao_usb_in_tx_which = 1 - ao_usb_in_tx_which;
+ ao_usb_tx_count = 0;
+}
+
+/* Wait for a free IN buffer. Interrupts are blocked */
+static void
+_ao_usb_in_wait(void)
+{
+ /* Wait for an IN buffer to be ready */
+ while ((ao_usb_in_pending & (1 << ao_usb_in_tx_which)) != 0)
+ ao_sleep(&ao_usb_in_pending);
+}
+
+void
+ao_usb_flush(void)
+{
+ if (!ao_usb_running)
+ return;
+
+ /* Anytime we've sent a character since
+ * the last time we flushed, we'll need
+ * to send a packet -- the only other time
+ * we would send a packet is when that
+ * packet was full, in which case we now
+ * want to send an empty packet
+ */
+ ao_arch_block_interrupts();
+ if (!ao_usb_in_flushed) {
+ _ao_usb_in_wait();
+ if (!ao_usb_in_flushed)
+ _ao_usb_in_send();
+ }
+ ao_arch_release_interrupts();
+}
+
+void
+ao_usb_putchar(char c)
+{
+ if (!ao_usb_running)
+ return;
+
+ if (c == '\n')
+ ao_usb_putchar('\r');
+ ao_arch_block_interrupts();
+ _ao_usb_in_wait();
+
+ ao_usb_in_flushed = 0;
+ ao_usb_in_buf[ao_usb_in_tx_which][ao_usb_tx_count++] = c;
+
+ /* Send the packet when full */
+ if (ao_usb_tx_count == AO_USB_IN_SIZE)
+ _ao_usb_in_send();
+
+ ao_arch_release_interrupts();
+ if (c == '\n')
+ ao_usb_flush();
+}
+#endif
+
+#if AO_USB_HAS_OUT
+#if !USE_USB_FIFO
+static bool
+_ao_usb_out_recv(void)
+{
+ uint8_t next_which = 1 - ao_usb_out_rx_which;
+
+ if ((ao_usb_out_avail & (1 << next_which)) != 0) {
+ /* switch current buffer */
+ ao_usb_out_rx_which = next_which;
+ ao_usb_out_avail &= (uint8_t) ~(1 << ao_usb_out_rx_which);
+
+ ao_usb_rx_count = (uint8_t) samd21_usb_desc_get_byte_count(AO_USB_OUT_EP, ao_usb_out_rx_which);
+ ao_usb_rx_pos = 0;
+ return true;
+ }
+ return false;
+}
+#endif
+
+static int
+_ao_usb_pollchar(void)
+{
+ uint8_t c;
+
+ if (!ao_usb_running)
+ return AO_READ_AGAIN;
+
+#if USE_USB_FIFO
+ if (ao_fifo_empty(&ao_usb_rx_fifo))
+ return AO_READ_AGAIN;
+ c = ao_fifo_remove(&ao_usb_rx_fifo);
+ ao_usb_fifo_check();
+#else
+ for (;;) {
+ if (ao_usb_rx_pos != ao_usb_rx_count)
+ break;
+
+ /* Check for packet */
+ if (!_ao_usb_out_recv())
+ return AO_READ_AGAIN;
+ }
+
+ /* Pull a character out of the fifo */
+ c = ao_usb_out_buf[ao_usb_out_rx_which][ao_usb_rx_pos++];
+
+ if (ao_usb_rx_pos == ao_usb_rx_count)
+ samd21_usb_ep_clr_ready(AO_USB_OUT_EP, ao_usb_out_rx_which);
+#endif
+
+ return c;
+}
+
+char
+ao_usb_getchar(void)
+{
+ int c;
+
+ ao_arch_block_interrupts();
+ while ((c = _ao_usb_pollchar()) == AO_READ_AGAIN)
+ ao_sleep(AO_USB_OUT_SLEEP_ADDR);
+ ao_arch_release_interrupts();
+ return (char) c;
+}
+
+#endif
+
+void
+ao_usb_disable(void)
+{
+ ao_arch_block_interrupts();
+ samd21_nvic_clear_enable(SAMD21_NVIC_ISR_USB_POS);
+
+ /* Disable USB pull-up */
+ samd21_usb.ctrlb |= (1 << SAMD21_USB_CTRLB_DETACH);
+
+ /* Switch off the device */
+ samd21_usb.ctrla &= (uint8_t) ~(1 << SAMD21_USB_CTRLA_ENABLE);
+
+ /* Disable the interface */
+ samd21_pm.apbbmask &= ~(1UL << SAMD21_PM_APBBMASK_USB);
+ ao_arch_release_interrupts();
+}
+
+void
+ao_usb_enable(void)
+{
+ int t;
+
+ /* Set up USB DM/DP pins */
+ samd21_port_pmux_set(&samd21_port_a, 24, SAMD21_PORT_PMUX_FUNC_G);
+ samd21_port_pmux_set(&samd21_port_a, 25, SAMD21_PORT_PMUX_FUNC_G);
+
+ /* Assign gclk 0 to USB reference */
+ samd21_gclk_clkctrl(AO_GCLK_USB, SAMD21_GCLK_CLKCTRL_ID_USB);
+
+ /* Enable USB clock */
+ samd21_pm.apbbmask |= (1 << SAMD21_PM_APBBMASK_USB);
+
+ /* Reset USB Device */
+
+ samd21_usb.ctrla |= (1 << SAMD21_USB_CTRLA_SWRST);
+
+ while ((samd21_usb.syncbusy & (1 << SAMD21_USB_SYNCBUSY_SWRST)) == 0)
+ ;
+
+ while ((samd21_usb.syncbusy & (1 << SAMD21_USB_SYNCBUSY_SWRST)) != 0)
+ ;
+
+ memset(&samd21_usb_desc, 0, sizeof (samd21_usb_desc));
+
+ /* Detach */
+ samd21_usb.ctrlb |= (1 << SAMD21_USB_CTRLB_DETACH);
+
+ samd21_usb.descadd = (uint32_t) &samd21_usb_desc;
+
+ /* Load calibration values */
+ uint32_t transn = ((samd21_aux1.calibration >> SAMD21_AUX1_CALIBRATION_USB_TRANSN) &
+ SAMD21_AUX1_CALIBRATION_USB_TRANSN_MASK);
+ if (transn == 0x1f)
+ transn = 5;
+ uint32_t transp = ((samd21_aux1.calibration >> SAMD21_AUX1_CALIBRATION_USB_TRANSP) &
+ SAMD21_AUX1_CALIBRATION_USB_TRANSP_MASK);
+ if (transp == 0x1f)
+ transp = 29;
+ uint32_t trim = ((samd21_aux1.calibration >> SAMD21_AUX1_CALIBRATION_USB_TRIM) &
+ SAMD21_AUX1_CALIBRATION_USB_TRIM_MASK);
+ if (trim == 7)
+ trim = 3;
+
+ samd21_usb.padcal = (uint16_t) ((transn << SAMD21_USB_PADCAL_TRANSN) |
+ (transp << SAMD21_USB_PADCAL_TRANSP) |
+ (trim << SAMD21_USB_PADCAL_TRIM));
+
+ samd21_usb.qosctrl = ((3 << SAMD21_USB_QOSCTRL_CQOS) |
+ (3 << SAMD21_USB_QOSCTRL_DQOS));
+
+ ao_arch_block_interrupts();
+
+ /* set full speed */
+ samd21_usb.ctrlb = (SAMD21_USB_CTRLB_SPDCONF_FS << SAMD21_USB_CTRLB_SPDCONF);
+
+ /* Set device mode */
+ samd21_usb.ctrla = ((0 << SAMD21_USB_CTRLA_MODE) |
+ (1 << SAMD21_USB_CTRLA_RUNSTDBY) |
+ (1 << SAMD21_USB_CTRLA_ENABLE));
+
+ while ((samd21_usb.syncbusy & (1 << SAMD21_USB_SYNCBUSY_ENABLE)) != 0)
+ ;
+
+ /* configure interrupts */
+ samd21_nvic_set_enable(SAMD21_NVIC_ISR_USB_POS);
+ samd21_nvic_set_priority(SAMD21_NVIC_ISR_USB_POS, 2);
+
+ samd21_usb.intenset = ((1 << SAMD21_USB_INTFLAG_EORST));
+
+ ao_arch_release_interrupts();
+
+ for (t = 0; t < 50000; t++)
+ ao_arch_nop();
+
+ /* Attach */
+ samd21_usb.ctrlb &= (uint16_t) ~(1 << SAMD21_USB_CTRLB_DETACH);
+}
+
+void
+ao_usb_init(void)
+{
+ ao_usb_enable();
+
+#if AO_USB_DEVICE_ID_SERIAL
+ ao_usb_serial_init();
+#endif
+
+ ao_usb_ep0_state = AO_USB_EP0_IDLE;
+}