--- /dev/null
+/*
+ * fw/mac.c - HardMAC functions
+ *
+ * Written 2011, 2013 by Werner Almesberger
+ * Copyright 2011, 2013 Werner Almesberger
+ *
+ * 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.
+ */
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "usb.h"
+
+#include "at86rf230.h"
+#include "spi.h"
+#include "board.h"
+#include "mac.h"
+
+#define RX_BUFS 3
+
+
+bool (*mac_irq)(void) = NULL;
+
+
+static uint8_t rx_buf[RX_BUFS][MAX_PSDU+2]; /* PHDR+payload+LQ */
+static uint8_t tx_buf[MAX_PSDU];
+static uint8_t tx_size = 0;
+static bool txing = 0;
+static bool queued_tx_ack = 0;
+static uint8_t next_seq, this_seq, queued_seq;
+
+
+/* ----- Receive buffer management ----------------------------------------- */
+
+
+static uint8_t rx_in = 0, rx_out = 0;
+
+
+static inline void next_buf(uint8_t *index)
+{
+ *index = (*index+1) % RX_BUFS;
+}
+
+
+/* ----- Interrupt handling ------------------------------------------------ */
+
+
+static void rx_done(void *user);
+static void tx_ack_done(void *user);
+
+
+static void usb_next(void)
+{
+ const uint8_t *buf;
+
+ if (rx_in != rx_out) {
+ buf = rx_buf[rx_out];
+ led(1);
+ usb_send(&eps[1], buf, buf[0]+2, rx_done, NULL);
+ }
+
+ if (queued_tx_ack) {
+ usb_send(&eps[1], &queued_seq, 1, tx_ack_done, NULL);
+ queued_tx_ack = 0;
+ }
+}
+
+
+static void tx_ack_done(void *user)
+{
+ usb_next();
+}
+
+static void rx_done(void *user)
+{
+ led(0);
+ next_buf(&rx_out);
+ usb_next();
+#ifdef AT86RF230
+ /* slap at86rf230 - reduce fragmentation issue */
+ change_state(TRX_STATUS_RX_AACK_ON);
+#endif
+}
+
+
+static void receive_frame(void)
+{
+ uint8_t size;
+ uint8_t *buf;
+
+ spi_begin();
+ spi_io(AT86RF230_BUF_READ);
+
+ size = spi_recv();
+ if (!size || (size & 0x80)) {
+ spi_end();
+ return;
+ }
+
+ buf = rx_buf[rx_in];
+ spi_recv_block(buf+1, size+1);
+ spi_end();
+
+ buf[0] = size;
+ next_buf(&rx_in);
+
+ if (eps[1].state == EP_IDLE)
+ usb_next();
+}
+
+
+static bool handle_irq(void)
+{
+ uint8_t irq;
+
+ irq = reg_read(REG_IRQ_STATUS);
+ if (!(irq & IRQ_TRX_END))
+ return 1;
+
+ if (txing) {
+ if (eps[1].state == EP_IDLE) {
+ usb_send(&eps[1], &this_seq, 1, tx_ack_done, NULL);
+ } else {
+ queued_tx_ack = 1;
+ queued_seq = this_seq;
+ }
+ txing = 0;
+ return 1;
+ }
+
+ /* likely */
+ if (eps[1].state == EP_IDLE || rx_in != rx_out)
+ receive_frame();
+
+ return 1;
+}
+
+
+/* ----- TX/RX ------------------------------------------------------------- */
+
+
+bool mac_rx(int on)
+{
+ if (on) {
+ mac_irq = handle_irq;
+ reg_read(REG_IRQ_STATUS);
+ change_state(TRX_CMD_RX_AACK_ON);
+ } else {
+ mac_irq = NULL;
+ change_state(TRX_CMD_FORCE_TRX_OFF);
+ txing = 0;
+ }
+ return 1;
+}
+
+
+static void do_tx(void *user)
+{
+ uint16_t timeout = 0xffff;
+ uint8_t status;
+ uint8_t i;
+
+ /*
+ * If we time out here, the host driver will time out waiting for the
+ * TRX_END acknowledgement.
+ */
+ do {
+ if (!--timeout)
+ return;
+ status = reg_read(REG_TRX_STATUS) & TRX_STATUS_MASK;
+ }
+ while (status != TRX_STATUS_RX_ON && status != TRX_STATUS_RX_AACK_ON);
+
+#ifdef AT86RF231
+ /*
+ * We use TRX_CMD_FORCE_PLL_ON instead of TRX_CMD_PLL_ON because a new
+ * reception may have begun while we were still working on the previous
+ * one.
+ */
+ reg_write(REG_TRX_STATE, TRX_CMD_FORCE_PLL_ON);
+#endif
+#ifdef AT86RF230
+ /*
+ * at86rf230 doesn't support force change, nevetherless this works
+ * somehow
+ */
+ reg_write(REG_TRX_STATE, TRX_CMD_PLL_ON);
+#endif
+#ifdef AT86RF212
+ /*
+ * We use TRX_CMD_FORCE_PLL_ON instead of TRX_CMD_PLL_ON because a new
+ * reception may have begun while we were still working on the previous
+ * one.
+ */
+ reg_write(REG_TRX_STATE, TRX_CMD_FORCE_PLL_ON);
+#endif
+
+ handle_irq();
+
+ spi_begin();
+ spi_send(AT86RF230_BUF_WRITE);
+ spi_send(tx_size+2); /* CRC */
+ for (i = 0; i != tx_size; i++)
+ spi_send(tx_buf[i]);
+ spi_end();
+
+ change_state(TRX_STATUS_TX_ARET_ON);
+
+ slp_tr();
+
+ txing = 1;
+ this_seq = next_seq;
+
+ /*
+ * Wait until we reach BUSY_TX_ARET, so that we command the transition to
+ * RX_AACK_ON which will be executed upon TX completion.
+ */
+ change_state(TRX_CMD_PLL_ON);
+ change_state(TRX_CMD_RX_AACK_ON);
+}
+
+
+bool mac_tx(uint16_t flags, uint8_t seq, uint16_t len)
+{
+ if (len > MAX_PSDU)
+ return 0;
+ tx_size = len;
+ next_seq = seq;
+ usb_recv(&eps[0], tx_buf, len, do_tx, NULL);
+ return 1;
+}
+
+
+void mac_reset(void)
+{
+ mac_irq = NULL;
+ txing = 0;
+ queued_tx_ack = 0;
+ rx_in = rx_out = 0;
+ next_seq = this_seq = queued_seq = 0;
+
+ /* enable CRC and PHY_RSSI (with RX_CRC_VALID) in SPI status return */
+ reg_write(REG_TRX_CTRL_1,
+ TX_AUTO_CRC_ON | SPI_CMD_MODE_PHY_RSSI << SPI_CMD_MODE_SHIFT);
+}
projects / linux-libre-firmware.git / blobdiff