- adc fix to work with kernels >=3.14

source/c_adc.c

@@ -30,47 +30,37 @@ SOFTWARE.
 #include "c_adc.h"
 #include "common.h"
 
-char adc_prefix_dir[40];
+const char *adc_prefix_dir = "/sys/bus/iio/devices/iio:device0/";
 
 int adc_initialized = 0;
 
 int initialize_adc(void)
 {
-    char test_path[40];
+    char test_path[60];
     FILE *fh;
     if (adc_initialized) {
         return 1;
     }
 
-    if (load_device_tree("cape-bone-iio")) {
-        build_path("/sys/devices", "ocp.", ocp_dir, sizeof(ocp_dir));
-        build_path(ocp_dir, "helper.", adc_prefix_dir, sizeof(adc_prefix_dir));
-        strncat(adc_prefix_dir, "/AIN", sizeof(adc_prefix_dir));
+    snprintf(test_path, sizeof(test_path), "%s", adc_prefix_dir);
+    fh = fopen(test_path, "r");
 
-        // Test that the directory has an AIN entry (found correct devicetree)
-        snprintf(test_path, sizeof(test_path), "%s%d", adc_prefix_dir, 0);
-
-        fh = fopen(test_path, "r");
-
-        if (!fh) {
-            return 0; 
-        }
-        fclose(fh);
-
-        adc_initialized = 1;
-        return 1;
+    if (!fh) {
+        return 0;
     }
+    fclose(fh);
 
-    return 0;
+    adc_initialized = 1;
+    return 1;
 }
 
 int read_value(unsigned int ain, float *value)
 {
     FILE * fh;
-    char ain_path[40];
+    char ain_path[60];
     int err, try_count=0;
     int read_successful;
-    snprintf(ain_path, sizeof(ain_path), "%s%d", adc_prefix_dir, ain);
+    snprintf(ain_path, sizeof(ain_path), "%s/in_voltage%d_raw", adc_prefix_dir, ain);
 
     read_successful = 0;
 

source/py_adc.c

@@ -45,8 +45,8 @@ static PyObject *py_setup_adc(PyObject *self, PyObject *args)
         Py_RETURN_NONE;
 
     PyErr_SetString(PyExc_RuntimeError, "Unable to setup ADC system. Possible causes are: \n"
-                                        "  - A cape with a conflicting pin mapping is loaded \n"
-                                        "  - A device tree object is loaded that uses the same name for a fragment: helper");
+                                        "  - Module 'ti_am335x_adc' is not loaded \n"
+                                        "  - ADC channels are not enabled in the overlay \n");
     return NULL;
 }
 
@@ -82,7 +82,7 @@ static PyObject *py_read(PyObject *self, PyObject *args)
     }
 
     //scale modifier
-    value = value / 1800.0;
+    value = value / 4095.0;
 
     py_value = Py_BuildValue("f", value);