type_logic.c

   1 /*
   2  * This file is part of the libsigrokdecode project.
   3  *
   4  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "libsigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
  21 #include "config.h"
  22 #include <inttypes.h>
  23 #include <string.h>
  24
  25 static PyObject *srd_logic_iter(PyObject *self)
  26 {
  27         return self;
  28 }
  29
  30 static PyObject *srd_logic_iternext(PyObject *self)
  31 {
  32         srd_logic *logic;
  33         PyObject *py_samplenum, *py_samples;
  34         uint8_t *sample_pos, sample;
  35         int byte_offset, bit_offset, i;
  36
  37         logic = (srd_logic *)self;
  38         if (logic->itercnt >= logic->inbuflen / logic->di->data_unitsize) {
  39                 /* End iteration loop. */
  40                 return NULL;
  41         }
  42
  43         /*
  44          * Convert the bit-packed sample to an array of bytes, with only 0x01
  45          * and 0x00 values, so the PD doesn't need to do any bitshifting.
  46          */
  47         sample_pos = logic->inbuf + logic->itercnt * logic->di->data_unitsize;
  48         for (i = 0; i < logic->di->dec_num_channels; i++) {
  49                 /* A channelmap value of -1 means "unused optional channel". */
  50                 if (logic->di->dec_channelmap[i] == -1) {
  51                         /* Value of unused channel is 0xff, instead of 0 or 1. */
  52                         logic->di->channel_samples[i] = 0xff;
  53                 } else {
  54                         byte_offset = logic->di->dec_channelmap[i] / 8;
  55                         bit_offset = logic->di->dec_channelmap[i] % 8;
  56                         sample = *(sample_pos + byte_offset) & (1 << bit_offset) ? 1 : 0;
  57                         logic->di->channel_samples[i] = sample;
  58                 }
  59         }
  60
  61         /* Prepare the next samplenum/sample list in this iteration. */
  62         py_samplenum =
  63             PyLong_FromUnsignedLongLong(logic->start_samplenum +
  64                                         logic->itercnt);
  65         PyList_SetItem(logic->sample, 0, py_samplenum);
  66         py_samples = PyBytes_FromStringAndSize((const char *)logic->di->channel_samples,
  67                                                logic->di->dec_num_channels);
  68         PyList_SetItem(logic->sample, 1, py_samples);
  69         Py_INCREF(logic->sample);
  70         logic->itercnt++;
  71
  72         return logic->sample;
  73 }
  74
  75 /** @cond PRIVATE */
  76 SRD_PRIV PyTypeObject srd_logic_type = {
  77         PyVarObject_HEAD_INIT(NULL, 0)
  78         .tp_name = "srd_logic",
  79         .tp_basicsize = sizeof(srd_logic),
  80         .tp_flags = Py_TPFLAGS_DEFAULT,
  81         .tp_doc = "Sigrokdecode logic sample object",
  82         .tp_iter = srd_logic_iter,
  83         .tp_iternext = srd_logic_iternext,
  84 };
  85 /** @endcond */