sensors: Add dummy light sensor

Some devices have a sysfs toggle for the lightsensor instead of
passing the LUX values for userspace processing; for those,
use BOARD_SYSFS_LIGHT_SENSOR:=<sysfs path>

This is necessary for the rest of userspace to recognize its existence
and toggle it for auto-brightness. It doesn't generate actual light
values, though; all backlight adjustments are made in-kernel.

Change-Id: I0e546b4740720bd34d1e1d85a96b295fcc697106

sensors: dummy ls: set unique handle

handles and types are usually the same, but it's not mandatory.
Sony DASH use custom handles, and the previous assumption broke
Proximity sensor on Sony devices.

Change-Id: I954e13765f42341e6b5393a12556f6a007c4e494

2 files changed, 52 insertions, 1 deletions

diff --git a/services/sensorservice/Android.mk b/services/sensorservice/Android.mk
index 773eca5..40fe6e1 100644
--- a/services/sensorservice/Android.mk
+++ b/services/sensorservice/Android.mk
@@ -26,7 +26,9 @@ LOCAL_SHARED_LIBRARIES := \
 	libui \
 	libgui
 
-
+ifneq ($(BOARD_SYSFS_LIGHT_SENSOR),)
+    LOCAL_CFLAGS += -DSYSFS_LIGHT_SENSOR=\"$(BOARD_SYSFS_LIGHT_SENSOR)\"
+endif
 
 LOCAL_MODULE:= libsensorservice
 
diff --git a/services/sensorservice/SensorDevice.cpp b/services/sensorservice/SensorDevice.cpp
index a9e3ef4..e115efc 100644
--- a/services/sensorservice/SensorDevice.cpp
+++ b/services/sensorservice/SensorDevice.cpp
@@ -31,11 +31,37 @@
 #include "SensorDevice.h"
 #include "SensorService.h"
 
+#ifdef SYSFS_LIGHT_SENSOR
+#include <fcntl.h>
+#endif
+
 namespace android {
 // ---------------------------------------------------------------------------
 
 ANDROID_SINGLETON_STATIC_INSTANCE(SensorDevice)
 
+#ifdef SYSFS_LIGHT_SENSOR
+#define DUMMY_ALS_HANDLE 0xdeadbeef
+static ssize_t addDummyLightSensor(sensor_t const **list, ssize_t count) {
+    struct sensor_t dummy_light =     {
+                  name            : "CyanogenMod dummy light sensor",
+                  vendor          : "CyanogenMod",
+                  version         : 1,
+                  handle          : DUMMY_ALS_HANDLE,
+                  type            : SENSOR_TYPE_LIGHT,
+                  maxRange        : 20,
+                  resolution      : 0.1,
+                  power           : 20,
+    };
+    void * new_list = malloc((count+1)*sizeof(sensor_t));
+    new_list = memcpy(new_list, *list, count*sizeof(sensor_t));
+    ((sensor_t *)new_list)[count] = dummy_light;
+    *list = (sensor_t const *)new_list;
+    count++;
+    return count;
+}
+#endif
+
 SensorDevice::SensorDevice()
     :  mSensorDevice(0),
        mSensorModule(0)
@@ -55,6 +81,9 @@ SensorDevice::SensorDevice()
         if (mSensorDevice) {
             sensor_t const* list;
             ssize_t count = mSensorModule->get_sensors_list(mSensorModule, &list);
+#ifdef SYSFS_LIGHT_SENSOR
+            count = addDummyLightSensor(&list, count);
+#endif
             mActivationCount.setCapacity(count);
             Info model;
             for (size_t i=0 ; i<size_t(count) ; i++) {
@@ -95,7 +124,11 @@ void SensorDevice::dump(String8& result, char* buffer, size_t SIZE)
 ssize_t SensorDevice::getSensorList(sensor_t const** list) {
     if (!mSensorModule) return NO_INIT;
     ssize_t count = mSensorModule->get_sensors_list(mSensorModule, list);
+#ifdef SYSFS_LIGHT_SENSOR
+    return addDummyLightSensor(list, count);
+#else
     return count;
+#endif
 }
 
 status_t SensorDevice::initCheck() const {
@@ -117,6 +150,22 @@ status_t SensorDevice::activate(void* ident, int handle, int enabled)
     status_t err(NO_ERROR);
     bool actuateHardware = false;
 
+#ifdef SYSFS_LIGHT_SENSOR
+    if (handle == DUMMY_ALS_HANDLE) {
+        int nwr, ret, fd;
+        char value[2];
+
+        fd = open(SYSFS_LIGHT_SENSOR, O_RDWR);
+        if(fd < 0)
+            return -ENODEV;
+
+        nwr = sprintf(value, "%s\n", enabled ? "1" : "0");
+        write(fd, value, nwr);
+        close(fd);
+        return 0;
+    }
+#endif
+
     Info& info( mActivationCount.editValueFor(handle) );