ht9170: Initial implementation

The driver implements support for the DTMF Shield based on the ht9170.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/ht9170/ht9170.cxx

@@ -0,0 +1,117 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2015 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <iostream>
+
+#include "ht9170.h"
+
+using namespace upm;
+using namespace std;
+
+HT9170::HT9170(int dr, int o1, int o2, int o3, int o4)
+{
+  // init the gpio's we will need
+  if ( !(m_dr = mraa_gpio_init(dr)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_gpio_init(dr) failed" << endl;
+      return;
+    }
+  mraa_gpio_dir(m_dr, MRAA_GPIO_IN);
+
+  if ( !(m_o1 = mraa_gpio_init(o1)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_gpio_init(o1) failed" << endl;
+      return;
+    }
+  mraa_gpio_dir(m_o1, MRAA_GPIO_IN);
+
+  if ( !(m_o2 = mraa_gpio_init(o2)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_gpio_init(o2) failed" << endl;
+      return;
+    }
+  mraa_gpio_dir(m_o2, MRAA_GPIO_IN);
+
+  if ( !(m_o3 = mraa_gpio_init(o3)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_gpio_init(o3) failed" << endl;
+      return;
+    }
+  mraa_gpio_dir(m_o3, MRAA_GPIO_IN);
+
+  if ( !(m_o4 = mraa_gpio_init(o4)) )
+    {
+      cerr << __FUNCTION__ << ": mraa_gpio_init(o4) failed" << endl;
+      return;
+    }
+  mraa_gpio_dir(m_o4, MRAA_GPIO_IN);
+}
+
+HT9170::~HT9170()
+{
+  mraa_gpio_close(m_dr);
+  mraa_gpio_close(m_o1);
+  mraa_gpio_close(m_o2);
+  mraa_gpio_close(m_o3);
+  mraa_gpio_close(m_o4);
+}
+
+bool HT9170::digitReady()
+{
+  return (mraa_gpio_read(m_dr) ? true : false);
+}
+
+char HT9170::decodeDigit()
+{
+  // This lookup table is derived from the decode table on page 7 of
+  // the HT9170B/HT9170D datasheet.
+
+  static const char decode[16] = {
+    'D',     // 0
+    '1',     // 1
+    '2',     // 2
+    '3',     // 3
+    '4',     // 4
+    '5',     // 5
+    '6',     // 6
+    '7',     // 7
+    '8',     // 8
+    '9',     // 9
+    '0',     // 10
+    '*',     // 11
+    '#',     // 12
+    'A',     // 13
+    'B',     // 14
+    'C'      // 15
+  };
+
+  uint8_t bits = 0;
+
+  bits = mraa_gpio_read(m_o1);
+  bits |= (mraa_gpio_read(m_o2) << 1);
+  bits |= (mraa_gpio_read(m_o3) << 2);
+  bits |= (mraa_gpio_read(m_o4) << 3);
+
+  return decode[bits];
+}