Move sensors multi HAL to libhardware

Change-Id: I12ba76291990264a2db61069f9610c40e96a9695

3 files changed, 545 insertions, 1 deletions

diff --git a/modules/Android.mk b/modules/Android.mk
index b2d5a2a..1935b11 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,3 +1,3 @@
 hardware_modules := gralloc hwcomposer audio nfc nfc-nci local_time \
-	power usbaudio audio_remote_submix camera consumerir
+	power usbaudio audio_remote_submix camera consumerir sensors
 include $(call all-named-subdir-makefiles,$(hardware_modules))
diff --git a/modules/sensors/Android.mk b/modules/sensors/Android.mk
new file mode 100644
index 0000000..6298ca0
--- /dev/null
+++ b/modules/sensors/Android.mk
@@ -0,0 +1,48 @@
+#
+# Copyright (C) 2013 The Android Open-Source 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.
+#
+
+ifeq ($(USE_SENSOR_MULTI_HAL),true)
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := sensors.$(TARGET_DEVICE)
+
+LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw
+
+LOCAL_CFLAGS := -DLOG_TAG=\"MultiHal\"
+LOCAL_SRC_FILES := multihal.cpp
+
+LOCAL_SHARED_LIBRARIES := \
+    liblog \
+    libcutils \
+    libdl \
+    libstlport \
+    libutils \
+    libcutils \
+    liblog \
+
+LOCAL_PRELINK_MODULE := false
+LOCAL_STRIP_MODULE := false
+
+LOCAL_C_INCLUDES := \
+    external/stlport/stlport \
+    bionic /
+
+include $(BUILD_SHARED_LIBRARY)
+
+endif # USE_SENSOR_MULTI_HAL
diff --git a/modules/sensors/multihal.cpp b/modules/sensors/multihal.cpp
new file mode 100644
index 0000000..45099b5
--- /dev/null
+++ b/modules/sensors/multihal.cpp
@@ -0,0 +1,496 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 <hardware/sensors.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <dirent.h>
+#include <math.h>
+#include <poll.h>
+#include <pthread.h>
+#include <linux/input.h>
+#include <cutils/atomic.h>
+#include <cutils/log.h>
+
+#include <vector>
+#include <map>
+
+#include <stdio.h>
+#include <dlfcn.h>
+
+// comment out to disable debug-level logging
+#define LOG_NDEBUG 0
+
+static const char* CONFIG_FILENAME = "/system/etc/sensors/hals.conf";
+static const char* LEGAL_SUBHAL_PATH_PREFIX = "/system/lib/hw/";
+static const int MAX_CONF_LINE_LENGTH = 1024;
+
+static pthread_mutex_t init_modules_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t init_sensors_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/*
+ * Vector of sub modules, whose indexes are referred to ni this file as module_index.
+ */
+static std::vector<hw_module_t *> *sub_hw_modules = NULL;
+
+/*
+ * Comparable class that globally identifies a sensor, by module index and local handle.
+ * A module index is the module's index in sub_hw_modules.
+ * A local handle is the handle the sub-module assigns to a sensor.
+ */
+struct FullHandle {
+    int moduleIndex;
+    int localHandle;
+
+    bool operator<(const FullHandle &that) const {
+        if (moduleIndex < that.moduleIndex) {
+            return true;
+        }
+        if (moduleIndex > that.moduleIndex) {
+            return false;
+        }
+        return localHandle < that.localHandle;
+    }
+
+    bool operator=(const FullHandle &that) const {
+        return moduleIndex == that.moduleIndex && localHandle == that.localHandle;
+    }
+};
+
+std::map<int, FullHandle> global_to_full;
+std::map<FullHandle, int> full_to_global;
+int next_global_handle = 1;
+
+static int assign_global_handle(int module_index, int local_handle) {
+    ALOGD("assign_global_handle %d %d", module_index, local_handle);
+    int global_handle = next_global_handle++;
+    FullHandle *full_handle = new FullHandle();
+    full_handle->moduleIndex = module_index;
+    full_handle->localHandle = local_handle;
+    full_to_global[*full_handle] = global_handle;
+    global_to_full[global_handle] = *full_handle;
+    return global_handle;
+}
+
+static int get_local_handle(int global_handle) {
+    return global_to_full[global_handle].localHandle;
+}
+
+static int get_module_index(int global_handle) {
+    ALOGD("get_module_index %d", global_handle);
+    FullHandle f = global_to_full[global_handle];
+    ALOGD("FullHandle moduleIndex %d, localHandle %d", f.moduleIndex, f.localHandle);
+    return f.moduleIndex;
+}
+
+
+/*
+ * Cache of all sensors, with original handles replaced by global handles.
+ * This will be handled to get_sensors_list() callers.
+ */
+static struct sensor_t const* global_sensors_list = NULL;
+static int global_sensors_count = -1;
+
+/*
+ * Extends a sensors_poll_device_1 by including all the sub-module's devices.
+ */
+struct sensors_poll_context_t {
+    /*
+     * This is the device that SensorDevice.cpp uses to make API calls
+     * to the multihal, which fans them out to sub-HALs.
+     */
+    sensors_poll_device_1 proxy_device; // must be first
+
+    void addSubHwDevice(struct hw_device_t*);
+
+    int activate(int handle, int enabled);
+    int setDelay(int handle, int64_t ns);
+    int poll(sensors_event_t* data, int count);
+    int batch(int handle, int flags, int64_t period_ns, int64_t timeout);
+    int flush(int handle);
+    int close();
+
+    std::vector<hw_device_t*> sub_hw_devices;
+
+    sensors_poll_device_t* get_v0_device_by_handle(int global_handle);
+    sensors_poll_device_1_t* get_v1_device_by_handle(int global_handle);
+    int get_device_version_by_handle(int global_handle);
+};
+
+void sensors_poll_context_t::addSubHwDevice(struct hw_device_t* sub_hw_device) {
+    ALOGD("addSubHwDevice");
+    this->sub_hw_devices.push_back(sub_hw_device);
+}
+
+sensors_poll_device_t* sensors_poll_context_t::get_v0_device_by_handle(int handle) {
+    ALOGD("get_v0_device_by_handle(%d)", handle);
+    int sub_index = get_module_index(handle);
+    ALOGD("sub_index: %d", sub_index);
+    return (sensors_poll_device_t*) this->sub_hw_devices[sub_index];
+}
+
+sensors_poll_device_1_t* sensors_poll_context_t::get_v1_device_by_handle(int handle) {
+    int sub_index = get_module_index(handle);
+    return (sensors_poll_device_1_t*) this->sub_hw_devices[sub_index];
+}
+
+int sensors_poll_context_t::get_device_version_by_handle(int handle) {
+    sensors_poll_device_t* v0 = this->get_v0_device_by_handle(handle);
+    return v0->common.version;
+}
+
+int sensors_poll_context_t::activate(int handle, int enabled) {
+    ALOGD("activate");
+    sensors_poll_device_t* v0 = this->get_v0_device_by_handle(handle);
+    int retval = v0->activate(v0, get_local_handle(handle), enabled);
+    ALOGD("retval %d", retval);
+    return retval;
+}
+
+int sensors_poll_context_t::setDelay(int handle, int64_t ns) {
+    ALOGD("setDelay");
+    sensors_poll_device_t* v0 = this->get_v0_device_by_handle(handle);
+    int retval = v0->setDelay(v0, get_local_handle(handle), ns);
+    ALOGD("retval %d", retval);
+    return retval;
+}
+
+int sensors_poll_context_t::poll(sensors_event_t *data, int count) {
+    ALOGD("poll");
+
+    // This only gets the first device. Parallel polling of multiple devices is coming soon.
+    int sub_index = 0;
+    sensors_poll_device_t* v0 = (sensors_poll_device_t*) this->sub_hw_devices[sub_index];
+
+    ALOGD("poll's blocking read begins...");
+    int retval = v0->poll(v0, data, count);
+    ALOGD("...poll's blocking read ends");
+    ALOGD("rewriting %d sensor handles...", retval);
+    // A normal event's "sensor" field is a local handles. Convert it to a global handle.
+    // A meta-data event must have its sensor set to 0, but it has a nested event
+    // with a local handle that needs to be converted to a global handle.
+    FullHandle full_handle;
+    full_handle.moduleIndex = sub_index;
+    for (int i = 0; i < retval; i++) {
+        sensors_event_t *event = &data[i];
+        // If it's a metadata event, rewrite the inner payload, not the sensor field.
+        if (event->type == SENSOR_TYPE_META_DATA) {
+            full_handle.localHandle = event->meta_data.sensor;
+            event->meta_data.sensor = full_to_global[full_handle];
+        } else {
+            full_handle.localHandle = event->sensor;
+            event->sensor = full_to_global[full_handle];
+        }
+    }
+    return retval;
+}
+
+int sensors_poll_context_t::batch(int handle, int flags, int64_t period_ns, int64_t timeout) {
+    ALOGD("batch");
+    int retval = -EINVAL;
+    int version = this->get_device_version_by_handle(handle);
+    if (version >= SENSORS_DEVICE_API_VERSION_1_0) {
+        sensors_poll_device_1_t* v1 = this->get_v1_device_by_handle(handle);
+        retval = v1->batch(v1, get_local_handle(handle), flags, period_ns, timeout);
+    }
+    ALOGD("retval %d", retval);
+    return retval;
+}
+
+int sensors_poll_context_t::flush(int handle) {
+    ALOGD("flush");
+    int retval = -EINVAL;
+    int version = this->get_device_version_by_handle(handle);
+    if (version >= SENSORS_DEVICE_API_VERSION_1_0) {
+        sensors_poll_device_1_t* v1 = this->get_v1_device_by_handle(handle);
+        retval = v1->flush(v1, get_local_handle(handle));
+    }
+    ALOGD("retval %d", retval);
+    return retval;
+}
+
+int sensors_poll_context_t::close() {
+    ALOGD("close");
+    for (std::vector<hw_device_t*>::iterator it = this->sub_hw_devices.begin();
+            it != this->sub_hw_devices.end(); it++) {
+        hw_device_t* dev = *it;
+        int retval = dev->close(dev);
+        ALOGD("retval %d", retval);
+    }
+    return 0;
+}
+
+
+static int device__close(struct hw_device_t *dev) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    if (ctx != NULL) {
+        int retval = ctx->close();
+        delete ctx;
+    }
+    return 0;
+}
+
+static int device__activate(struct sensors_poll_device_t *dev, int handle,
+        int enabled) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    return ctx->activate(handle, enabled);
+}
+
+static int device__setDelay(struct sensors_poll_device_t *dev, int handle,
+        int64_t ns) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    return ctx->setDelay(handle, ns);
+}
+
+static int device__poll(struct sensors_poll_device_t *dev, sensors_event_t* data,
+        int count) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    return ctx->poll(data, count);
+}
+
+static int device__batch(struct sensors_poll_device_1 *dev, int handle,
+        int flags, int64_t period_ns, int64_t timeout) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    return ctx->batch(handle, flags, period_ns, timeout);
+}
+
+static int device__flush(struct sensors_poll_device_1 *dev, int handle) {
+    sensors_poll_context_t* ctx = (sensors_poll_context_t*) dev;
+    return ctx->flush(handle);
+}
+
+static int open_sensors(const struct hw_module_t* module, const char* name,
+        struct hw_device_t** device);
+
+static bool starts_with(const char* s, const char* prefix) {
+    if (s == NULL || prefix == NULL) {
+        return false;
+    }
+    size_t s_size = strlen(s);
+    size_t prefix_size = strlen(prefix);
+    return s_size >= prefix_size && strncmp(s, prefix, prefix_size) == 0;
+}
+
+/*
+ * Adds valid paths from the config file to the vector passed in.
+ * The vector must not be null.
+ */
+static void get_so_paths(std::vector<char*> *so_paths) {
+    FILE *conf_file = fopen(CONFIG_FILENAME, "r");
+    if (conf_file == NULL) {
+        ALOGD("No multihal config file found at %s", CONFIG_FILENAME);
+        return;
+    }
+    ALOGD("Multihal config file found at %s", CONFIG_FILENAME);
+    char *line = NULL;
+    size_t len = 0;
+    int line_count = 0;
+    while (getline(&line, &len, conf_file) != -1) {
+        // overwrite trailing eoln with null char
+        char* pch = strchr(line, '\n');
+        if (pch != NULL) {
+            *pch = '\0';
+        }
+        ALOGD("config file line #%d: '%s'", ++line_count, line);
+        char *real_path = realpath(line, NULL);
+        if (starts_with(real_path, LEGAL_SUBHAL_PATH_PREFIX)) {
+            ALOGD("accepting valid path '%s'", real_path);
+            char* compact_line = new char[strlen(real_path) + 1];
+            strcpy(compact_line, real_path);
+            so_paths->push_back(compact_line);
+        } else {
+            ALOGD("rejecting path '%s' because it does not start with '%s'",
+                    real_path, LEGAL_SUBHAL_PATH_PREFIX);
+        }
+        free(real_path);
+    }
+    free(line);
+    fclose(conf_file);
+    ALOGD("hals.conf contained %d lines", line_count);
+}
+
+/*
+ * Ensures that the sub-module array is initialized.
+ * This can be first called from get_sensors_list or from open_sensors.
+ */
+static void lazy_init_modules() {
+    pthread_mutex_lock(&init_modules_mutex);
+    if (sub_hw_modules != NULL) {
+        pthread_mutex_unlock(&init_modules_mutex);
+        return;
+    }
+    std::vector<char*> *so_paths = new std::vector<char*>();
+    get_so_paths(so_paths);
+
+    // dlopen the module files and cache their module symbols in sub_hw_modules
+    sub_hw_modules = new std::vector<hw_module_t *>();
+    dlerror(); // clear any old errors
+    const char* sym = HAL_MODULE_INFO_SYM_AS_STR;
+    for (std::vector<char*>::iterator it = so_paths->begin(); it != so_paths->end(); it++) {
+        char* path = *it;
+        void* lib_handle = dlopen(path, RTLD_LAZY);
+        if (lib_handle == NULL) {
+            ALOGD("dlerror(): %s", dlerror());
+        } else {
+            ALOGD("hal lib was loaded: %s", path);
+            ALOGD("Opening symbol \"%s\"", sym);
+            // clear old errors
+            dlerror();
+            struct hw_module_t* module = (hw_module_t*) dlsym(lib_handle, sym);
+            const char* error;
+            if ((error = dlerror()) != NULL) {
+                ALOGD("Error calling dlsym: %s", error);
+            } else if (module == NULL) {
+                ALOGD("module == NULL");
+            } else {
+                ALOGD("OK, dlsym()'ed \"%s\"", sym);
+                sub_hw_modules->push_back(module);
+            }
+        }
+    }
+    pthread_mutex_unlock(&init_modules_mutex);
+}
+
+/*
+ * Lazy-initializes global_sensors_count, global_sensors_list, and module_sensor_handles.
+ */
+static void lazy_init_sensors_list() {
+    ALOGD("lazy_init_sensors_list");
+    pthread_mutex_lock(&init_sensors_mutex);
+    if (global_sensors_list != NULL) {
+        // already initialized
+        pthread_mutex_unlock(&init_sensors_mutex);
+        ALOGD("lazy_init_sensors_list - early return");
+        return;
+    }
+
+    ALOGD("lazy_init_sensors_list needs to do work");
+    lazy_init_modules();
+
+    // Count all the sensors, then allocate an array of blanks.
+    global_sensors_count = 0;
+    const struct sensor_t *subhal_sensors_list;
+    for (std::vector<hw_module_t*>::iterator it = sub_hw_modules->begin();
+            it != sub_hw_modules->end(); it++) {
+        struct sensors_module_t *module = (struct sensors_module_t*) *it;
+        global_sensors_count += module->get_sensors_list(module, &subhal_sensors_list);
+        ALOGD("increased global_sensors_count to %d", global_sensors_count);
+    }
+
+    // The global_sensors_list is full of consts.
+    // Manipulate this non-const list, and point the const one to it when we're done.
+    sensor_t* mutable_sensor_list = new sensor_t[global_sensors_count];
+
+    // index of the next sensor to set in mutable_sensor_list
+    int mutable_sensor_index = 0;
+    int module_index = 0;
+
+    for (std::vector<hw_module_t*>::iterator it = sub_hw_modules->begin();
+            it != sub_hw_modules->end(); it++) {
+        hw_module_t *hw_module = *it;
+        ALOGD("examine one module");
+        // Read the sub-module's sensor list.
+        struct sensors_module_t *module = (struct sensors_module_t*) hw_module;
+        int module_sensor_count = module->get_sensors_list(module, &subhal_sensors_list);
+        ALOGD("the module has %d sensors", module_sensor_count);
+
+        // Copy the HAL's sensor list into global_sensors_list,
+        // with the handle changed to be a global handle.
+        for (int i = 0; i < module_sensor_count; i++) {
+            ALOGD("examining one sensor");
+            const struct sensor_t *local_sensor = &subhal_sensors_list[i];
+            int local_handle = local_sensor->handle;
+            memcpy(&mutable_sensor_list[mutable_sensor_index], local_sensor,
+                sizeof(struct sensor_t));
+
+            // Overwrite the global version's handle with a global handle.
+            int global_handle = assign_global_handle(module_index, local_handle);
+
+            mutable_sensor_list[mutable_sensor_index].handle = global_handle;
+            ALOGD("module_index %d, local_handle %d, global_handle %d",
+                    module_index, local_handle, global_handle);
+
+            mutable_sensor_index++;
+        }
+        module_index++;
+    }
+    // Set the const static global_sensors_list to the mutable one allocated by this function.
+    global_sensors_list = mutable_sensor_list;
+
+    pthread_mutex_unlock(&init_sensors_mutex);
+    ALOGD("end lazy_init_sensors_list");
+}
+
+static int module__get_sensors_list(struct sensors_module_t* module,
+        struct sensor_t const** list) {
+    ALOGD("module__get_sensors_list");
+    lazy_init_sensors_list();
+    *list = global_sensors_list;
+    return global_sensors_count;
+}
+
+static struct hw_module_methods_t sensors_module_methods = {
+    open : open_sensors
+};
+
+struct sensors_module_t HAL_MODULE_INFO_SYM = {
+    common :{
+        tag : HARDWARE_MODULE_TAG,
+        version_major : 1,
+        version_minor : 0,
+        id : SENSORS_HARDWARE_MODULE_ID,
+        name : "MultiHal Sensor Module",
+        author : "Google, Inc",
+        methods : &sensors_module_methods,
+        dso : NULL,
+        reserved : {0},
+    },
+    get_sensors_list : module__get_sensors_list
+};
+
+static int open_sensors(const struct hw_module_t* hw_module, const char* name,
+        struct hw_device_t** hw_device_out) {
+    ALOGD("open_sensors begin...");
+
+    lazy_init_modules();
+
+    // Create proxy device, to return later.
+    sensors_poll_context_t *dev = new sensors_poll_context_t();
+    memset(dev, 0, sizeof(sensors_poll_device_1_t));
+    dev->proxy_device.common.tag = HARDWARE_DEVICE_TAG;
+    dev->proxy_device.common.version = SENSORS_DEVICE_API_VERSION_1_0;
+    dev->proxy_device.common.module = const_cast<hw_module_t*>(hw_module);
+    dev->proxy_device.common.close = device__close;
+    dev->proxy_device.activate = device__activate;
+    dev->proxy_device.setDelay = device__setDelay;
+    dev->proxy_device.poll = device__poll;
+    dev->proxy_device.batch = device__batch;
+    dev->proxy_device.flush = device__flush;
+
+    // Open() the subhal modules. Remember their devices in a vector parallel to sub_hw_modules.
+    for (std::vector<hw_module_t*>::iterator it = sub_hw_modules->begin();
+            it != sub_hw_modules->end(); it++) {
+        sensors_module_t *sensors_module = (sensors_module_t*) *it;
+        struct hw_device_t* sub_hw_device;
+        int sub_open_result = sensors_module->common.methods->open(*it, name, &sub_hw_device);
+        dev->addSubHwDevice(sub_hw_device);
+    }
+
+    // Prepare the output param and return
+    *hw_device_out = &dev->proxy_device.common;
+    ALOGD("...open_sensors end");
+    return 0;
+}