protocol.c

Go to the documentation of this file.

// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2011 by Martin Schmoelzer                               *
 *   <martin.schmoelzer@student.tuwien.ac.at>                              *
 ***************************************************************************/
 
#include "protocol.h"
#include "jtag.h"
#include "delay.h"
#include "usb.h"
#include "io.h"
#include "msgtypes.h"
 
#include "reg_ezusb.h"
 
volatile uint8_t cmd_id_index;
 
volatile uint8_t payload_index_in;
 
void execute_set_led_command(void)
{
    uint8_t led_state = OUT2BUF[cmd_id_index + 1];
 
    if (led_state & RUN_LED_ON)
        SET_RUN_LED();
 
    if (led_state & COM_LED_ON)
        SET_COM_LED();
 
    if (led_state & RUN_LED_OFF)
        CLEAR_RUN_LED();
 
    if (led_state & COM_LED_OFF)
        CLEAR_COM_LED();
}
 
bool execute_command(void)
{
    uint8_t usb_out_bytecount, usb_in_bytecount;
    uint16_t signal_state;
    uint16_t count;
 
    /* Most commands do not transfer IN data. To save code space, we write 0 to
     * usb_in_bytecount here, then modify it in the switch statement below where
     * necessary */
    usb_in_bytecount = 0;
 
    switch (OUT2BUF[cmd_id_index] /* Command ID */) {
        case CMD_SCAN_IN:
            usb_out_bytecount = 5;
            usb_in_bytecount = OUT2BUF[cmd_id_index + 1];
            jtag_scan_in(cmd_id_index + 1, payload_index_in);
            break;
        case CMD_SCAN_OUT:
            usb_out_bytecount = OUT2BUF[cmd_id_index + 1] + 5;
            jtag_scan_out(cmd_id_index + 1);
            break;
        case CMD_SCAN_IO:
            usb_in_bytecount = OUT2BUF[cmd_id_index + 1];
            usb_out_bytecount = usb_in_bytecount + 5;
            jtag_scan_io(cmd_id_index + 1, payload_index_in);
            break;
        case CMD_CLOCK_TMS:
            usb_out_bytecount = 2;
            jtag_clock_tms(OUT2BUF[cmd_id_index + 1], OUT2BUF[cmd_id_index + 2]);
            break;
        case CMD_CLOCK_TCK:
            usb_out_bytecount = 2;
            count = (uint16_t)OUT2BUF[cmd_id_index + 1];
            count |= ((uint16_t)OUT2BUF[cmd_id_index + 2]) << 8;
            jtag_clock_tck(count);
            break;
        case CMD_SLOW_SCAN_IN:
            usb_out_bytecount = 5;
            usb_in_bytecount = OUT2BUF[cmd_id_index + 1];
            jtag_slow_scan_in(cmd_id_index + 1, payload_index_in);
            break;
        case CMD_SLOW_SCAN_OUT:
            usb_out_bytecount = OUT2BUF[cmd_id_index + 1] + 5;
            jtag_slow_scan_out(cmd_id_index + 1);
            break;
        case CMD_SLOW_SCAN_IO:
            usb_in_bytecount = OUT2BUF[cmd_id_index + 1];
            usb_out_bytecount = usb_in_bytecount + 5;
            jtag_slow_scan_io(cmd_id_index + 1, payload_index_in);
            break;
        case CMD_SLOW_CLOCK_TMS:
            usb_out_bytecount = 2;
            jtag_slow_clock_tms(OUT2BUF[cmd_id_index + 1], OUT2BUF[cmd_id_index + 2]);
            break;
        case CMD_SLOW_CLOCK_TCK:
            usb_out_bytecount = 2;
            count = (uint16_t)OUT2BUF[cmd_id_index + 1];
            count |= ((uint16_t)OUT2BUF[cmd_id_index + 2]) << 8;
            jtag_slow_clock_tck(count);
            break;
        case CMD_SLEEP_US:
            usb_out_bytecount = 2;
            count = (uint16_t)OUT2BUF[cmd_id_index + 1];
            count |= ((uint16_t)OUT2BUF[cmd_id_index + 2]) << 8;
            delay_us(count);
            break;
        case CMD_SLEEP_MS:
            usb_out_bytecount = 2;
            count = (uint16_t)OUT2BUF[cmd_id_index + 1];
            count |= ((uint16_t)OUT2BUF[cmd_id_index + 2]) << 8;
            delay_ms(count);
            break;
        case CMD_GET_SIGNALS:
            usb_out_bytecount = 0;
            usb_in_bytecount = 2;
            signal_state = jtag_get_signals();
            IN2BUF[payload_index_in] = (signal_state >> 8) & 0x00FF;
            IN2BUF[payload_index_in + 1] = signal_state & 0x00FF;
            break;
        case CMD_SET_SIGNALS:
            usb_out_bytecount = 2;
            jtag_set_signals(OUT2BUF[cmd_id_index + 1], OUT2BUF[cmd_id_index + 2]);
            break;
        case CMD_CONFIGURE_TCK_FREQ:
            usb_out_bytecount = 5;
            jtag_configure_tck_delay(
            OUT2BUF[cmd_id_index + 1],  /* scan_in */
            OUT2BUF[cmd_id_index + 2],  /* scan_out */
            OUT2BUF[cmd_id_index + 3],  /* scan_io */
            OUT2BUF[cmd_id_index + 4],  /* clock_tck */
            OUT2BUF[cmd_id_index + 5]); /* clock_tms */
            break;
        case CMD_SET_LEDS:
            usb_out_bytecount = 1;
            execute_set_led_command();
            break;
        case CMD_TEST:
            usb_out_bytecount = 1;
            /* Do nothing... This command is only used to test if the device is ready
             * to accept new commands */
            break;
        default:
            /* Should never be reached */
            usb_out_bytecount = 0;
            break;
    }
 
    /* Update EP2 Bulk-IN data byte count */
    payload_index_in += usb_in_bytecount;
 
    /* Determine if this was the last command */
    if ((cmd_id_index + usb_out_bytecount + 1) >= OUT2BC)
        return true;
    else {
        /* Not the last command, update cmd_id_index */
        cmd_id_index += (usb_out_bytecount + 1);
        return false;
    }
}
 
void command_loop(void)
{
    bool last_command;
 
    while (1) {
        cmd_id_index = 0;
        payload_index_in = 0;
 
        /* Wait until host sends EP2 Bulk-OUT packet */
        while (!EP2_out)
            ;
        EP2_out = 0;
 
        /* Turn on COM LED to indicate command execution */
        SET_COM_LED();
 
        /* Execute the commands */
        last_command = false;
        while (last_command == false)
            last_command = execute_command();
 
        CLEAR_COM_LED();
 
        /* Send back EP2 Bulk-IN packet if required */
        if (payload_index_in > 0) {
            IN2BC = payload_index_in;
            while (!EP2_in)
                ;
            EP2_in = 0;
        }
 
        /* Re-arm EP2-OUT after command execution */
        OUT2BC = 0;
    }
}