liblights: Expose panel brightness in helper lib

Change-Id: I810166818eac84466dfe2c4b88dff47e83a181c0

liblights/Android.mk

@@ -12,17 +12,30 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ifneq ($(TARGET_PROVIDES_LIBLIGHT),true)
-
 LOCAL_PATH := $(call my-dir)
 
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES := lights.c
+LOCAL_SRC_FILES := lights_helper.c
 
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+
+LOCAL_SHARED_LIBRARIES := liblog
+
+LOCAL_MODULE := liblights_helper
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_STATIC_LIBRARY)
+
+ifneq ($(TARGET_PROVIDES_LIBLIGHT),true)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := lights.c
 
 LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_STATIC_LIBRARIES := liblights_helper
 
 LOCAL_MODULE := lights.$(TARGET_BOOTLOADER_BOARD_NAME)
 LOCAL_MODULE_RELATIVE_PATH := hw

liblights/include/liblights/samsung_lights_helper.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SAMSUNG_LIGHTS_HELPER_H
+#define SAMSUNG_LIGHTS_HELPER_H
+
+#include <samsung_lights.h>
+
+/*
+ * Interfaces for other modules accessing lights HAL data.
+ * For documentation, see lights_helper.c
+ */
+extern int set_cur_button_brightness(const int brightness);
+extern int get_cur_panel_brightness();
+extern int get_max_panel_brightness();
+extern int set_cur_panel_brightness(const int brightness);
+extern int set_max_panel_brightness(const int brightness);
+
+#endif // SAMSUNG_LIGHTS_HELPER_H

liblights/lights.c

@@ -30,6 +30,7 @@
 #include <sys/types.h>
 
 #include <hardware/lights.h>
+#include <liblights/samsung_lights_helper.h>
 
 #include "samsung_lights.h"
 
@@ -58,63 +59,6 @@ void init_g_lock(void)
     pthread_mutex_init(&g_lock, NULL);
 }
 
-static int read_int(char const *path)
-{
-    int fd, len;
-    int num_bytes = 10;
-    char buf[11];
-    int retval;
-
-    fd = open(path, O_RDONLY);
-    if (fd < 0) {
-        ALOGE("%s: failed to open %s\n", __func__, path);
-        goto fail;
-    }
-
-    len = read(fd, buf, num_bytes - 1);
-    if (len < 0) {
-        ALOGE("%s: failed to read from %s\n", __func__, path);
-        goto fail;
-    }
-
-    buf[len] = '\0';
-    close(fd);
-
-    // no endptr, decimal base
-    retval = strtol(buf, NULL, 10);
-    return retval == 0 ? -1 : retval;
-
-fail:
-    if (fd >= 0)
-        close(fd);
-    return -1;
-}
-
-static int write_int(char const *path, int value)
-{
-    int fd;
-    static int already_warned;
-
-    already_warned = 0;
-
-    ALOGV("write_int: path %s, value %d", path, value);
-    fd = open(path, O_RDWR);
-
-    if (fd >= 0) {
-        char buffer[20];
-        int bytes = sprintf(buffer, "%d\n", value);
-        int amt = write(fd, buffer, bytes);
-        close(fd);
-        return amt == -1 ? -errno : 0;
-    } else {
-        if (already_warned == 0) {
-            ALOGE("write_int failed to open %s\n", path);
-            already_warned = 1;
-        }
-        return -errno;
-    }
-}
-
 static int write_str(char const *path, const char* value)
 {
     int fd;
@@ -165,7 +109,7 @@ static int set_light_backlight(struct light_device_t *dev __unused,
     }
 
     pthread_mutex_lock(&g_lock);
-    err = write_int(PANEL_BRIGHTNESS_NODE, brightness);
+    err = set_cur_panel_brightness(brightness);
     if (err == 0)
         g_backlight.cur_brightness = brightness;
 
@@ -181,7 +125,7 @@ static int set_light_buttons(struct light_device_t* dev __unused,
 
     pthread_mutex_lock(&g_lock);
 
-    err = write_int(BUTTON_BRIGHTNESS_NODE, on ? 1 : 0);
+    err = set_cur_button_brightness(on ? 1 : 0);
 
     pthread_mutex_unlock(&g_lock);
 
@@ -359,7 +303,7 @@ static int open_lights(const struct hw_module_t *module, char const *name,
     else
         return -EINVAL;
 
-    int max_brightness = read_int(PANEL_MAX_BRIGHTNESS_NODE);
+    int max_brightness = get_max_panel_brightness();
     if (max_brightness < 0) {
         ALOGE("%s: failed to read max panel brightness, fallback to 255!",
             __func__);

liblights/lights_helper.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <cutils/log.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <liblights/samsung_lights_helper.h>
+
+/*
+ * Reads an Integer from a file.
+ *
+ * @param path The absolute path string.
+ * @return The Integer with decimal base, -1 on error.
+ */
+int read_int(char const *path)
+{
+    int fd, len;
+    int num_bytes = 10;
+    char buf[11];
+    int retval;
+
+    fd = open(path, O_RDONLY);
+    if (fd < 0) {
+        ALOGE("%s: failed to open %s\n", __func__, path);
+        goto fail;
+    }
+
+    len = read(fd, buf, num_bytes - 1);
+    if (len < 0) {
+        ALOGE("%s: failed to read from %s\n", __func__, path);
+        goto fail;
+    }
+
+    buf[len] = '\0';
+    close(fd);
+
+    // no endptr, decimal base
+    retval = strtol(buf, NULL, 10);
+    return retval == 0 ? -1 : retval;
+
+fail:
+    if (fd >= 0)
+        close(fd);
+    return -1;
+}
+
+/*
+ * Writes an Integer to a file.
+ *
+ * @param path The absolute path string.
+ * @param value The Integer value to be written.
+ * @return 0 on success, -1 or errno on error.
+ */
+int write_int(char const *path, const int value)
+{
+    int fd;
+    static int already_warned;
+
+    already_warned = 0;
+
+    ALOGV("write_int: path %s, value %d", path, value);
+    fd = open(path, O_RDWR);
+
+    if (fd >= 0) {
+        char buffer[20];
+        int bytes = sprintf(buffer, "%d\n", value);
+        int amt = write(fd, buffer, bytes);
+        close(fd);
+        return amt == -1 ? -errno : 0;
+    } else {
+        if (already_warned == 0) {
+            ALOGE("write_int failed to open %s\n", path);
+            already_warned = 1;
+        }
+        return -errno;
+    }
+}
+
+/*
+ * Set the current button brightness via sysfs.
+ *
+ * @param brightness The brightness value.
+ * @return 0 on success, -1 or errno on error.
+ */
+inline int set_cur_button_brightness(const int brightness)
+{
+    return write_int(BUTTON_BRIGHTNESS_NODE, brightness);
+}
+
+/*
+ * Read the current panel brightness from sysfs.
+ *
+ * @return The brightness as Integer, -1 on error.
+ */
+inline int get_cur_panel_brightness()
+{
+    return read_int(PANEL_BRIGHTNESS_NODE);
+}
+
+/*
+ * Read the maximum panel brightness from sysfs.
+ *
+ * @return The brightness as Integer, -1 on error.
+ */
+inline int get_max_panel_brightness()
+{
+    return read_int(PANEL_MAX_BRIGHTNESS_NODE);
+}
+
+/*
+ * Set the current panel brightness via sysfs.
+ *
+ * @param brightness The (scaled) brightness value.
+ * @return 0 on success, -1 or errno on error.
+ */
+inline int set_cur_panel_brightness(const int brightness)
+{
+    return write_int(PANEL_BRIGHTNESS_NODE, brightness);
+}
+
+/*
+ * Set the maximum panel brightness via sysfs.
+ *
+ * @param brightness The brightness value.
+ * @return 0 on success, -1 or errno on error.
+ */
+inline int set_max_panel_brightness(const int brightness)
+{
+    return write_int(PANEL_MAX_BRIGHTNESS_NODE, brightness);
+}