65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
/*
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* This file is part of the sigrok project.
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*
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* Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libusb.h>
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#include "command.h"
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#include "sigrok.h"
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#include "sigrok-internal.h"
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int command_start_acquisition(libusb_device_handle *devhdl,
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uint64_t samplerate)
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{
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struct cmd_start_acquisition cmd;
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int delay = 0;
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/* Compute the sample rate */
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if((SR_MHZ(48) % samplerate) == 0)
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{
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cmd.flags = CMD_START_FLAGS_CLK_48MHZ;
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delay = SR_MHZ(48) / samplerate - 1;
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} else if((SR_MHZ(30) % samplerate) == 0) {
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cmd.flags = CMD_START_FLAGS_CLK_30MHZ;
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delay = SR_MHZ(30) / samplerate - 1;
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}
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/* Note that sample_delay=0 is treated as sample_delay=256 */
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if (delay <= 0 || delay > 256) {
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sr_err("fx2lafw: Unable to sample at %dHz",
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samplerate);
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return SR_ERR;
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}
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cmd.sample_delay = delay;
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/* Send the control message */
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const int res = libusb_control_transfer(devhdl,
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LIBUSB_REQUEST_TYPE_VENDOR |
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LIBUSB_ENDPOINT_OUT, CMD_START, 0x0000,
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0x0000, (unsigned char*)&cmd,
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sizeof(cmd), 100);
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if (res < 0) {
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sr_err("fx2lafw: Unable to send start command: %d",
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res);
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return SR_ERR;
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}
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return SR_OK;
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}
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