pwm: Refined API. Work towards functionality

* Private functions added
* Added to CMakeLists

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>

api/pwm.h

@@ -59,13 +59,22 @@ namespace maa {
  */
 class PWM {
 
+private:
+    int chipid, pin;
+    FILE *duty_fp;
+
+    void write_period(int period);
+    void write_duty(int duty);
+    int setup_duty_fp();
+
 public:
 
     /** Create an PWM object
      *
-     *  @param pin The PWM pin to operate on.
+     *  @param chipid The chip in which the following pin is on.
+     *  @param pin The PWM channel to operate on
      */
-    PWM(int pin);
+    PWM(int chipid, int pin);
 
     /** Set the ouput duty-cycle percentage, as a float
      *

src/CMakeLists.txt

@@ -9,6 +9,7 @@ set (maa_LIB_SRCS
   ${PROJECT_SOURCE_DIR}/src/i2c/i2cslave.cxx
   ${PROJECT_SOURCE_DIR}/src/i2c/smbus.c
   ${PROJECT_SOURCE_DIR}/src/gpio/gpio.c
+  ${PROJECT_SOURCE_DIR}/src/pwm/pwm.cxx
 )
 
 add_library (maa STATIC ${maa_LIB_SRCS})

src/pwm/pwm.cxx

@@ -0,0 +1,136 @@
+/*
+ * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
+ *
+ * Copyright © 2014 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 "pwm.h"
+
+using namespace maa;
+
+PWM::PWM(int chipin, int pinin)
+{
+    chipid = chipin;
+    pin = pinin;
+
+    FILE *export_f;
+    char buffer[64];
+    snprintf(buffer, 64, "/sys/class/pwm/pwmchip%d/export", chipid);
+
+    if((export_f = fopen(buffer, "w")) == NULL) {
+        fprintf(stderr, "Failed to open export for writing!\n");
+    } else {
+        fprintf(export_f, "%d", pin);
+        fclose(export_f);
+    }
+}
+
+void
+PWM::write(float percentage)
+{
+    //DO some writting
+}
+
+float
+PWM::read()
+{
+    //Do Something
+}
+
+void
+PWM::period(float seconds)
+{
+    //Do Something
+}
+
+void
+PWM::period_ms(int ms)
+{
+    //Do Something
+}
+
+void
+PWM::perod_us(int us)
+{
+    //Do Something
+}
+
+void
+PWM::pulsewidth(float seconds)
+{
+    //Do Something
+}
+
+void
+PWM::pulsewidth_ms(int ms)
+{
+    //Do Something
+}
+
+void
+PWM::pulsewidth_us(int us)
+{
+    //Do Something
+}
+
+void
+PWM::enable(int enable)
+{
+    //Do Something
+}
+
+void
+PWM::close()
+{
+    //Do Something
+}
+
+void
+PWM::write_period(int period)
+{
+    //Impossible
+}
+
+void
+PWM::write_duty(int duty)
+{
+    if(duty_fp == NULL) {
+        setup_duty_fp();
+    }
+    fseek(duty_fp, SEEK_SET, 0);
+    fprintf(duty_fp, "%d", duty);
+    fseek(duty_fp, SEEK_SET, 0);
+}
+
+int
+PWM::setup_duty_fp()
+{
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/duty_cycle", chipid, pin);
+
+    if((duty_fp = fopen(bu, "r+b")) == NULL) {
+        return 1;
+    } else {
+        return 0;
+    }
+    return 1;
+}