initial cleanup and mapping

wiringPi/mcp23s17.c

@@ -0,0 +1,236 @@
+/*
+ * mcp23s17.c:
+ *	Extend wiringPi with the MCP 23s17 SPI GPIO expander chip
+ *	Copyright (c) 2013 Gordon Henderson
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ *    wiringPi is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as
+ *    published by the Free Software Foundation, either version 3 of the
+ *    License, or (at your option) any later version.
+ *
+ *    wiringPi is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public
+ *    License along with wiringPi.
+ *    If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#include "wiringPi.h"
+#include "wiringPiSPI.h"
+#include "mcp23x0817.h"
+
+#include "mcp23s17.h"
+
+#define	MCP_SPEED	4000000
+
+
+
+/*
+ * writeByte:
+ *	Write a byte to a register on the MCP23s17 on the SPI bus.
+ *********************************************************************************
+ */
+
+static void writeByte (uint8_t spiPort, uint8_t devId, uint8_t reg, uint8_t data)
+{
+  uint8_t spiData [4] ;
+
+  spiData [0] = CMD_WRITE | ((devId & 7) << 1) ;
+  spiData [1] = reg ;
+  spiData [2] = data ;
+
+  wiringPiSPIDataRW (spiPort, spiData, 3) ;
+}
+
+/*
+ * readByte:
+ *	Read a byte from a register on the MCP23s17 on the SPI bus.
+ *********************************************************************************
+ */
+
+static uint8_t readByte (uint8_t spiPort, uint8_t devId, uint8_t reg)
+{
+  uint8_t spiData [4] ;
+
+  spiData [0] = CMD_READ | ((devId & 7) << 1) ;
+  spiData [1] = reg ;
+
+  wiringPiSPIDataRW (spiPort, spiData, 3) ;
+
+  return spiData [2] ;
+}
+
+
+/*
+ * myPinMode:
+ *********************************************************************************
+ */
+
+static void myPinMode (struct wiringPiNodeStruct *node, int pin, int mode)
+{
+  int mask, old, reg ;
+
+  pin -= node->pinBase ;
+
+  if (pin < 8)		// Bank A
+    reg  = MCP23x17_IODIRA ;
+  else
+  {
+    reg  = MCP23x17_IODIRB ;
+    pin &= 0x07 ;
+  }
+
+  mask = 1 << pin ;
+  old  = readByte (node->data0, node->data1, reg) ;
+
+  if (mode == OUTPUT)
+    old &= (~mask) ;
+  else
+    old |=   mask ;
+
+  writeByte (node->data0, node->data1, reg, old) ;
+}
+
+
+/*
+ * myPullUpDnControl:
+ *********************************************************************************
+ */
+
+static void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int mode)
+{
+  int mask, old, reg ;
+
+  pin -= node->pinBase ;
+
+  if (pin < 8)		// Bank A
+    reg  = MCP23x17_GPPUA ;
+  else
+  {
+    reg  = MCP23x17_GPPUB ;
+    pin &= 0x07 ;
+  }
+
+  mask = 1 << pin ;
+  old  = readByte (node->data0, node->data1, reg) ;
+
+  if (mode == PUD_UP)
+    old |=   mask ;
+  else
+    old &= (~mask) ;
+
+  writeByte (node->data0, node->data1, reg, old) ;
+}
+
+
+/*
+ * myDigitalWrite:
+ *********************************************************************************
+ */
+
+static void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value)
+{
+  int bit, old ;
+
+  pin -= node->pinBase ;	// Pin now 0-15
+
+  bit = 1 << (pin & 7) ;
+
+  if (pin < 8)			// Bank A
+  {
+    old = node->data2 ;
+
+    if (value == LOW)
+      old &= (~bit) ;
+    else
+      old |=   bit ;
+
+    writeByte (node->data0, node->data1, MCP23x17_GPIOA, old) ;
+    node->data2 = old ;
+  }
+  else				// Bank B
+  {
+    old = node->data3 ;
+
+    if (value == LOW)
+      old &= (~bit) ;
+    else
+      old |=   bit ;
+
+    writeByte (node->data0, node->data1, MCP23x17_GPIOB, old) ;
+    node->data3 = old ;
+  }
+}
+
+
+/*
+ * myDigitalRead:
+ *********************************************************************************
+ */
+
+static int myDigitalRead (struct wiringPiNodeStruct *node, int pin)
+{
+  int mask, value, gpio ;
+
+  pin -= node->pinBase ;
+
+  if (pin < 8)		// Bank A
+    gpio  = MCP23x17_GPIOA ;
+  else
+  {
+    gpio  = MCP23x17_GPIOB ;
+    pin  &= 0x07 ;
+  }
+
+  mask  = 1 << pin ;
+  value = readByte (node->data0, node->data1, gpio) ;
+
+  if ((value & mask) == 0)
+    return LOW ;
+  else 
+    return HIGH ;
+}
+
+
+/*
+ * mcp23s17Setup:
+ *	Create a new instance of an MCP23s17 SPI GPIO interface. We know it
+ *	has 16 pins, so all we need to know here is the SPI address and the
+ *	user-defined pin base.
+ *********************************************************************************
+ */
+
+int mcp23s17Setup (const int pinBase, const int spiPort, const int devId)
+{
+  int    x ;
+  struct wiringPiNodeStruct *node ;
+
+  if ((x = wiringPiSPISetup (spiPort, MCP_SPEED)) < 0)
+    return x ;
+
+  writeByte (spiPort, devId, MCP23x17_IOCON,  IOCON_INIT | IOCON_HAEN) ;
+  writeByte (spiPort, devId, MCP23x17_IOCONB, IOCON_INIT | IOCON_HAEN) ;
+
+  node = wiringPiNewNode (pinBase, 16) ;
+
+  node->data0           = spiPort ;
+  node->data1           = devId ;
+  node->pinMode         = myPinMode ;
+  node->pullUpDnControl = myPullUpDnControl ;
+  node->digitalRead     = myDigitalRead ;
+  node->digitalWrite    = myDigitalWrite ;
+  node->data2           = readByte (spiPort, devId, MCP23x17_OLATA) ;
+  node->data3           = readByte (spiPort, devId, MCP23x17_OLATB) ;
+
+  return 0 ;
+}