Merge branch 'pwm' into for-pull

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 +1,205 @@
+/*
+ * 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 <stdlib.h>
+
+#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);
+        setup_duty_fp();
+    }
+}
+
+void
+PWM::write(float percentage)
+{
+    write_duty(percentage*get_period());
+}
+
+float
+PWM::read()
+{
+    float output = get_duty() / (float) get_period();
+    return output;
+}
+
+void
+PWM::period(float seconds)
+{
+    period_ms(seconds*1000);
+}
+
+void
+PWM::period_ms(int ms)
+{
+    period_us(ms*1000);
+}
+
+void
+PWM::period_us(int us)
+{
+    write_period(us*1000);
+}
+
+void
+PWM::pulsewidth(float seconds)
+{
+    pulsewidth_ms(seconds*1000);
+}
+
+void
+PWM::pulsewidth_ms(int ms)
+{
+    pulsewidth_us(ms*1000);
+}
+
+void
+PWM::pulsewidth_us(int us)
+{
+    write_duty(us*1000);
+}
+
+void
+PWM::enable(int enable)
+{
+    int status;
+    if(enable != 0) {
+        status = 1;
+    } else {
+        status = enable;
+    }
+    FILE *enable_f;
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/enable", chipid, pin);
+
+    if((enable_f = fopen(bu, "w")) == NULL) {
+        fprintf(stderr, "Failed to open export for writing!\n");
+    } else {
+        fprintf(enable_f, "%d", status);
+        fclose(enable_f);
+    }
+    //Do Something
+}
+
+void
+PWM::close()
+{
+    enable(0);
+    FILE *unexport_f;
+    char buffer[64];
+    snprintf(buffer, 64, "/sys/class/pwm/pwmchip%d/unexport", chipid);
+
+    if((unexport_f = fopen(buffer, "w")) == NULL) {
+        fprintf(stderr, "Failed to open unexport for writing!\n");
+    } else {
+        fprintf(unexport_f, "%d", pin);
+        fclose(unexport_f);
+    }
+}
+
+void
+PWM::write_period(int period)
+{
+    FILE *period_f;
+    char bu[64];
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/period", chipid, pin);
+
+    if((period_f = fopen(bu, "r+b")) == NULL) {
+        fprintf(stderr, "Failed to open period for writing!\n");
+    } else {
+        fprintf(period_f, "%d", period);
+        fclose(period_f);
+    }
+}
+
+void
+PWM::write_duty(int duty)
+{
+    if(duty_fp == NULL) {
+        setup_duty_fp();
+    }
+    fprintf(duty_fp, "%d", duty);
+    rewind(duty_fp);
+    fflush(duty_fp);
+}
+
+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;
+}
+
+int
+PWM::get_period()
+{
+    FILE *period_f;
+    char bu[64];
+    char output[16];
+
+    sprintf(bu, "/sys/class/pwm/pwmchip%d/pwm%d/period", chipid, pin);
+    if((period_f = fopen(bu, "rb")) == NULL) {
+        fprintf(stderr, "Failed to open period for reading!\n");
+        return 0;
+    } else {
+        fgets(output, 16, period_f);
+        fclose(period_f);
+        return atoi(output);
+    }
+}
+
+int
+PWM::get_duty()
+{
+    if(duty_fp == NULL) {
+        setup_duty_fp();
+    }
+    char output[16];
+    fgets(output, 16, duty_fp);
+    fseek(duty_fp, SEEK_SET, 0);
+    return atoi(output);
+}