文章目錄
- 前言
- HIDL 簡介
-
- 啟動流程
- HIDL 使用
- Jni 流程： HIDL 用戶端使用
- HIDL 服務端
- 相關檔案
-
- 0.【Java 安卓LED服務類】LightsService.java
- 1.【JNI 用戶端實作】com_android_server_lights_LightsService.cpp
- 2.【HIDL 客戶】ILight.與 HIDL 服務庫通信.hal
- 3.【HIDL 客戶】LightAll.cpp.調用 HIDL 服務庫
- 4.【HIDL 服務】[email protected].啟動注冊 HIDL 服務庫
- 4.【HIDL 服務】service.cpp.向上注冊 HIDL 服務庫
- 5.【HIDL 服務】Light.h
- 6.【HIDL 服務】Light.cpp.加載調用傳統庫
- 7.【HAL 實作】lights.c.傳統 HAL 庫
- 8.【核心實作】leds-qpnp.c
前言
學習筆記，簡單介紹了 light 在 Android 8.0 上的整個調用流程
更新上添加下調用流程線，将各個檔案串起來
HIDL 簡介
一張圖開場
其實主要是就是将以前那種 Java-> Jni -> Hal -> Kernel 的結構變成了
Java -> Jni -> Binder 用戶端 ====== Binder 通信 ======> Binder 服務端 -> Hal -> Kernel
将 framework 與 Hal 之間的互動變成了 CS 結構了。
插播下 Java Binder 服務編寫框圖：
C++ Binder 服務編寫框圖：
啟動流程
// SystemServer.java (frameworks\base\services\java\com\android\server)
import com.android.server.lights.LightsService;
startBootstrapServices()
# 此函數可參考 BatteryService 流程分析
mSystemServiceManager.startService(LightsService.class);
// SystemServiceManager.java (frameworks\base\services\core\java\com\android\server)
startService(Class<T> serviceClass)
# 擷取類名
final String name = serviceClass.getName();
# 獲得構造函數： public LightsService(Context context)
Constructor<T> constructor = serviceClass.getConstructor(Context.class);
# 調用構造函數，建立類對象
service = constructor.newInstance(mContext);
// LightsService.java (frameworks\base\services\core\java\com\android\server\lights)
// 構造函數：
LightsService(Context context)
super(context);
for (int i = 0; i < LightsManager.LIGHT_ID_COUNT; i++) {
mLights[i] = new LightImpl(i);
}
# 添加到 SystemService 連結清單中管理，并啟動服務
startService(service);
mServices.add(service);
service.onStart();
// LightsService.java (frameworks\base\services\core\java\com\android\server\lights)
onStart()
// 這是向 systemservice.java 注冊了一些回調，隻讓其調用使用？
// Publish the service so it is only accessible to the system process
// 讓其隻能在 system 程序中通路？
// ./base/services/core/java/com/android/server/power/PowerManagerService.java:736:
// mBatteryManagerInternal = getLocalService(BatteryManagerInternal.class);
publishLocalService(LightsManager.class, mService);
HIDL 使用
// 接口檔案：
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\ILight.hal
package [email protected];
interface ILight {
/**
* Set the provided lights to the provided values.
*
* @param type logical light to set
* @param state describes what the light should look like.
* @return status result of applying state transformation.
*/
setLight(Type type, LightState state) generates (Status status);
/**
* Discover what indicator lights are available.
*
* @return types list of available lights
*/
getSupportedTypes() generates (vec<Type> types);
};
// 編譯檔案：
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\Android.bp
filegroup {
name: "[email protected]_hal",
srcs: [
"types.hal",
"ILight.hal",
],
}
genrule {
name: "[email protected]_genc++",
tools: ["hidl-gen"],
cmd: "$(location hidl-gen) -o $(genDir) -Lc++-sources -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport [email protected]",
srcs: [
":[email protected]_hal",
],
out: [
"android/hardware/light/2.0/types.cpp",
"android/hardware/light/2.0/LightAll.cpp",
],
}
// 編譯工具： out/host/linux-x86/bin/hidl-gen
// 生成檔案：
// Z:\work\A306_eng\src\out\soong\.intermediates\hardware\interfaces\light\2.0\[email protected]_genc++\gen\android\hardware\light\2.0\LightAll.cpp
getService(): 擷取 servicemanager 中的對應 binder 服務
BnHwLight::onTransact()# 伺服器端，調用具體子類提供服務操作硬體
_hidl_mImpl->setLight(type, *state);
BpHwLight::setLight(Type type, const LightState& state): # 用戶端，提供遠端調用服務端接口
1. 填充 Parcel 資料
2. 調用 remote() 通過 binder 調用到伺服器端執行
_hidl_err = remote()->transact(1 /* setLight */, _hidl_data, &_hidl_reply);
Jni 流程： HIDL 用戶端使用
// com_android_server_lights_LightsService.cpp (frameworks\base\services\core\jni)
static void setLight_native( JNIEnv* /* env */, jobject /* clazz */, jint light, jint colorARGB, jint flashMode, jint onMS, jint offMS,jint brightnessMode)
# HAL 服務擷取: HIDL 接口，從 servicemanager 中擷取 Light 服務
sp<ILight> hal = LightHal::associate();
// will return the hal if it exists the first time.
sLight = ILight::getService();
// Z:\work\A306_eng\src\out\soong\.intermediates\hardware\interfaces\light\2.0\[email protected]_genc++\gen\android\hardware\light\2.0\LightAll.cpp
::android::sp<ILight> ILight::getService(const std::string &serviceName, const bool getStub)
const sp<::android::hidl::manager::V1_0::IServiceManager> sm = defaultServiceManager();
Return<Transport> transportRet = sm->getTransport(ILight::descriptor, serviceName);
if (getStub || vintfPassthru || vintfLegacy) {
# 擷取 PassthroughServiceManager 服務
const sp<::android::hidl::manager::V1_0::IServiceManager> pm = getPassthroughServiceManager();
Return<sp<::android::hidl::base::V1_0::IBase>> ret = pm->get(ILight::descriptor, serviceName);
// ServiceManagement.cpp (system\libhidl\transport)
struct PassthroughServiceManager : IServiceManager {
Return<sp<IBase>> get(const hidl_string& fqName,
const hidl_string& name)
{
# PassthroughServiceManager 的 get(const hidl_string& fqName, const hidl_string& name)
# 函數根據傳入的 fqName=([email protected]::ICameraProvider"),
# 擷取目前的接口名ICameraProvider，
# 拼接出後面需要載入的函數名：HIDL_FETCH_ICameraProvider 和庫名字：
# [email protected]
std::string stdFqName(fqName.c_str());
//fqName looks like [email protected]::IFoo
size_t idx = stdFqName.find("::");
if (idx == std::string::npos ||
idx + strlen("::") + 1 >= stdFqName.size()) {
LOG(ERROR) << "Invalid interface name passthrough lookup: " << fqName;
return nullptr;
}
std::string packageAndVersion = stdFqName.substr(0, idx);
std::string ifaceName = stdFqName.substr(idx + strlen("::"));
const std::string prefix = packageAndVersion + "-impl";
const std::string sym = "HIDL_FETCH_" + ifaceName;
# 接着通過 dlopen 載入 /vendor/lib/hw/[email protected]；
# 通過 dlsym 載入 HIDL_FETCH_ICameraProvider 函數
# 至此正式進入cameraprovider的implement
std::vector<std::string> libs = search(path, prefix, ".so");
handle = dlopen(fullPath.c_str(), dlMode);
IBase* (*generator)(const char* name);
*(void **)(&generator) = dlsym(handle, sym.c_str());
IBase *interface = (*generator)(name.c_str());
#################################################################
# 調用 HIDL 服務入口函數
#################################################################
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\default\Light.cpp
ILight* HIDL_FETCH_ILight(const char* /* name */) {
std::map<Type, light_device_t*> lights;
for(auto const &pair : kLogicalLights) {
Type type = pair.first;
const char* name = pair.second;
light_device_t* light = getLightDevice(name);
#############################################
# 老 HAL 庫加載
#############################################
light_device_t* getLightDevice(const char* name)
int ret = hw_get_module (LIGHTS_HARDWARE_MODULE_ID, &hwModule);
// Lights.c (hardware\qcom\display\liblight)
struct hw_module_t HAL_MODULE_INFO_SYM = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = LIGHTS_HARDWARE_MODULE_ID,
.name = "lights Module",
.author = "Google, Inc.",
.methods = &lights_module_methods,
};
static struct hw_module_methods_t lights_module_methods = {
.open = open_lights,
};
ret = hwModule->methods->open(hwModule, name,reinterpret_cast<hw_device_t**>(&lightDevice));
// Light.cpp (vendor\qcom\proprietary\fastmmi\module\light)
open_lights(const struct hw_module_t* module, char const* name,struct hw_device_t** device)
set_light = set_light_notifications;
handle_speaker_battery_locked(dev);
set_speaker_light_locked(dev, &g_notification);
// [email protected] 20180111 begein
// 閃爍之前清燈狀态
write_int(RED_LED_FILE, 0);
write_int(GREEN_LED_FILE, 0);
write_int(BLUE_LED_FILE, 0);
# 往 /sys/class/leds/green/brightness 這類的結點寫亮度值
fd = open(path, O_RDWR);
int bytes = snprintf(buffer, sizeof(buffer), "%d\n", value);
ssize_t amt = write(fd, buffer, (size_t)bytes);
close(fd);
// [email protected] 20180111 end
if (light != nullptr) {
lights[type] = light;
}
}
if (lights.size() == 0) {
// Log information, but still return new Light.
// Some devices may not have any lights.
ALOGI("Could not open any lights.");
}
return new Light(std::move(lights));
}
Type type = static_cast<Type>(light);
// 構造 LightState 狀态類
LightState state = constructState( colorARGB, flashMode, onMS, offMS, brightnessMode);
ALOGD_IF_SLOW(50, "Excessive delay setting light");
# HIDL 接口向 HAL 下發燈狀态給他處理
Return<Status> ret = hal->setLight(type, state);
# 處理通信傳回值
processReturn(ret, type, state);
HIDL 服務端
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\default\Android.mk
include $(CLEAR_VARS)
LOCAL_MODULE_RELATIVE_PATH := hw
LOCAL_PROPRIETARY_MODULE := true
LOCAL_MODULE := [email protected]
LOCAL_INIT_RC := [email protected]
LOCAL_SRC_FILES := \
service.cpp \
LOCAL_SHARED_LIBRARIES := \
liblog \
libcutils \
libdl \
libbase \
libutils \
libhardware \
LOCAL_SHARED_LIBRARIES += \
libhidlbase \
libhidltransport \
[email protected] \
include $(BUILD_EXECUTABLE)
// 服務啟動：
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\default\[email protected]
service light-hal-2-0 /vendor/bin/hw/[email protected]
class hal
user system
group system
// Z:\work\A306_eng\src\hardware\interfaces\light\2.0\default\service.cpp
int main() {
return defaultPassthroughServiceImplementation<ILight>();
/
// LegacySupport.h (system\libhidl\transport\include\hidl)
defaultPassthroughServiceImplementation(std::string name, size_t maxThreads = 1)
configureRpcThreadpool(maxThreads, true);
configureBinderRpcThreadpool(maxThreads, callerWillJoin);
ProcessState::self()->setThreadPoolConfiguration(maxThreads, callerWillJoin /*callerJoinsPool*/);
status_t result = registerPassthroughServiceImplementation<Interface>(name);
registerPassthroughServiceImplementation( std::string name = "default")
sp<Interface> service = Interface::getService(name, true /* getStub */);
status_t status = service->registerAsService(name);
joinRpcThreadpool();
joinBinderRpcThreadpool();
IPCThreadState::self()->joinThreadPool();
}
相關檔案
下面将從上到下介紹：
0.【Java 安卓LED服務類】LightsService.java
public class LightsService extends SystemService {
// 下一級 Jni 接口
static native void setLight_native(int light, int color, int mode,
int onMS, int offMS, int brightnessMode);
}
1.【JNI 用戶端實作】com_android_server_lights_LightsService.cpp
static const JNINativeMethod method_table[] = {
{ "setLight_native", "(IIIIII)V", (void*)setLight_native },
};
static void setLight_native(
JNIEnv* /* env */,
jobject /* clazz */,
jint light,
jint colorARGB,
jint flashMode,
jint onMS,
jint offMS,
jint brightnessMode) {
if (!validate(light, flashMode, brightnessMode)) {
return;
}
sp<ILight> hal = LightHal::associate();
if (hal == nullptr) {
return;
}
Type type = static_cast<Type>(light);
LightState state = constructState(
colorARGB, flashMode, onMS, offMS, brightnessMode);
{
ALOGD_IF_SLOW(50, "Excessive delay setting light");
// 下一級入口
Return<Status> ret = hal->setLight(type, state);
processReturn(ret, type, state);
}
}
2.【HIDL 客戶】ILight.與 HIDL 服務庫通信.hal
定義了 HIDL 接口
package [email protected];
interface ILight {
/**
* Set the provided lights to the provided values.
*
* @param type logical light to set
* @param state describes what the light should look like.
* @return status result of applying state transformation.
*/
setLight(Type type, LightState state) generates (Status status);
/**
* Discover what indicator lights are available.
*
* @return types list of available lights
*/
getSupportedTypes() generates (vec<Type> types);
};
3.【HIDL 客戶】LightAll.cpp.調用 HIDL 服務庫
::android::status_t BnHwLight::onTransact(
uint32_t _hidl_code,
const ::android::hardware::Parcel &_hidl_data,
::android::hardware::Parcel *_hidl_reply,
uint32_t _hidl_flags,
TransactCallback _hidl_cb)
// 下一級接口
Status _hidl_out_status = _hidl_mImpl->setLight(type, *state);
4.【HIDL 服務】[email protected].啟動注冊 HIDL 服務庫
service light-hal-2-0 /vendor/bin/hw/android.hardware.ligh[email protected]
class hal
user system
group system
4.【HIDL 服務】service.cpp.向上注冊 HIDL 服務庫
int main() {
return defaultPassthroughServiceImplementation<ILight>();
/
// LegacySupport.h (system\libhidl\transport\include\hidl)
defaultPassthroughServiceImplementation(std::string name, size_t maxThreads = 1)
configureRpcThreadpool(maxThreads, true);
configureBinderRpcThreadpool(maxThreads, callerWillJoin);
ProcessState::self()->setThreadPoolConfiguration(maxThreads, callerWillJoin /*callerJoinsPool*/);
status_t result = registerPassthroughServiceImplementation<Interface>(name);
registerPassthroughServiceImplementation( std::string name = "default")
sp<Interface> service = Interface::getService(name, true /* getStub */);
status_t status = service->registerAsService(name);
joinRpcThreadpool();
joinBinderRpcThreadpool();
IPCThreadState::self()->joinThreadPool();
5.【HIDL 服務】Light.h
namespace android {
namespace hardware {
namespace light {
namespace V2_0 {
namespace implementation {
using ::android::hardware::light::V2_0::ILight;
using ::android::hardware::light::V2_0::LightState;
using ::android::hardware::light::V2_0::Status;
using ::android::hardware::light::V2_0::Type;
using ::android::hardware::Return;
using ::android::hardware::Void;
using ::android::hardware::hidl_vec;
using ::android::hardware::hidl_string;
using ::android::sp;
struct Light : public ILight {
Light(std::map<Type, light_device_t*> &&lights);
// Methods from ::android::hardware::light::V2_0::ILight follow.
Return<Status> setLight(Type type, const LightState& state) override;
Return<void> getSupportedTypes(getSupportedTypes_cb _hidl_cb) override;
private:
std::map<Type, light_device_t*> mLights;
};
extern "C" ILight* HIDL_FETCH_ILight(const char* name);
} // namespace implementation
} // namespace V2_0
} // namespace light
} // namespace hardware
} // namespace android
6.【HIDL 服務】Light.cpp.加載調用傳統庫
ILight* HIDL_FETCH_ILight(const char* /* name */) {
std::map<Type, light_device_t*> lights;
for(auto const &pair : kLogicalLights) {
Type type = pair.first;
const char* name = pair.second;
// 加載傳統 HAL 庫
light_device_t* light = getLightDevice(name);
if (light != nullptr) {
lights[type] = light;
}
}
if (lights.size() == 0) {
// Log information, but still return new Light.
// Some devices may not have any lights.
ALOGI("Could not open any lights.");
}
return new Light(std::move(lights));
}
Light::Light(std::map<Type, light_device_t*> &&lights)
: mLights(std::move(lights)) {}
// Methods from ::android::hardware::light::V2_0::ILight follow.
Return<Status> Light::setLight(Type type, const LightState& state) {
auto it = mLights.find(type);
if (it == mLights.end()) {
return Status::LIGHT_NOT_SUPPORTED;
}
light_device_t* hwLight = it->second;
light_state_t legacyState {
.color = state.color,
.flashMode = static_cast<int>(state.flashMode),
.flashOnMS = state.flashOnMs,
.flashOffMS = state.flashOffMs,
.brightnessMode = static_cast<int>(state.brightnessMode),
};
int ret = hwLight->set_light(hwLight, &legacyState);
switch (ret) {
case -ENOSYS:
return Status::BRIGHTNESS_NOT_SUPPORTED;
case 0:
return Status::SUCCESS;
default:
return Status::UNKNOWN;
}
}
7.【HAL 實作】lights.c.傳統 HAL 庫
/*
* The lights Module
*/
struct hw_module_t HAL_MODULE_INFO_SYM = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = LIGHTS_HARDWARE_MODULE_ID,
.name = "lights Module",
.author = "Google, Inc.",
.methods = &lights_module_methods,
};
/**
* module methods
*/
/** Open a new instance of a lights device using name */
static int open_lights(const struct hw_module_t* module, char const* name,
struct hw_device_t** device)
{
int (*set_light)(struct light_device_t* dev,
struct light_state_t const* state);
if (0 == strcmp(LIGHT_ID_BACKLIGHT, name)) {
char property[PROPERTY_VALUE_MAX];
property_get("persist.extend.brightness", property, "0");
if(!(strncmp(property, "1", PROPERTY_VALUE_MAX)) ||
!(strncmp(property, "true", PROPERTY_VALUE_MAX))) {
property_get("persist.display.max_brightness", property, "255");
g_brightness_max = atoi(property);
set_brightness_ext_init();
set_light = set_light_backlight_ext;
} else
// 調用接口 set_light , 上層會調用到這裡來
set_light = set_light_backlight;
} else if (0 == strcmp(LIGHT_ID_BATTERY, name))
set_light = set_light_battery;
else if (0 == strcmp(LIGHT_ID_NOTIFICATIONS, name))
set_light = set_light_notifications;
else if (0 == strcmp(LIGHT_ID_BUTTONS, name)) {
if (!access(BUTTON_FILE, F_OK)) {
// enable light button when the file is present
set_light = set_light_buttons;
} else {
return -EINVAL;
}
}
else if (0 == strcmp(LIGHT_ID_ATTENTION, name))
set_light = set_light_attention;
else
return -EINVAL;
pthread_once(&g_init, init_globals);
struct light_device_t *dev = malloc(sizeof(struct light_device_t));
if(!dev)
return -ENOMEM;
memset(dev, 0, sizeof(*dev));
dev->common.tag = HARDWARE_DEVICE_TAG;
dev->common.version = LIGHTS_DEVICE_API_VERSION_2_0;
dev->common.module = (struct hw_module_t*)module;
dev->common.close = (int (*)(struct hw_device_t*))close_lights;
dev->set_light = set_light;
*device = (struct hw_device_t*)dev;
return 0;
}
# 更新燈則通過 sys/class/led/xxx/bright 來操作的
// char const*const RED_LED_FILE = "/sys/class/leds/red/brightness";
set_speaker_light_locked(struct light_device_t* dev,
struct light_state_t const* state)
write_int(RED_LED_FILE, 0);
int bytes = snprintf(buffer, sizeof(buffer), "%d\n", value);
ssize_t amt = write(fd, buffer, (size_t)bytes);
8.【核心實作】leds-qpnp.c
【充電 CHG_LED 可用紅燈配置流程】：
// Msm8937-pmi8940-mtp.dtsi (kernel\msm-3.18\arch\arm64\boot\dts\qcom)
&pmi8940_charger {
qcom,battery-data = <&mtp_batterydata>;
qcom,chg-led-sw-controls;
qcom,chg-led-support;
};
解析使用位置：Qpnp-smbcharger.c (kernel\msm-3.18\drivers\power)
static int __init smbchg_init(void)
// static struct spmi_driver smbchg_driver = {
// .driver = {
// .name = "qpnp-smbcharger",
// .owner = THIS_MODULE,
// .of_match_table = smbchg_match_table,
// .pm = &smbchg_pm_ops,
// },
// .probe = smbchg_probe,
// .remove = smbchg_remove,
// .shutdown = smbchg_shutdown,
// };
return spmi_driver_register(&smbchg_driver);
smbchg_probe(struct spmi_device *spmi)
smb_parse_dt(struct smbchg_chip *chip)
chip->cfg_chg_led_support = of_property_read_bool(node, "qcom,chg-led-support");
。。。
if (chip->cfg_chg_led_support && chip->schg_version == QPNP_SCHG_LITE)
rc = smbchg_register_chg_led(chip);
chip->led_cdev.name = "red";
chip->led_cdev.brightness_set = smbchg_chg_led_brightness_set;
chip->led_cdev.brightness_get = smbchg_chg_led_brightness_get;
rc = led_classdev_register(chip->dev, &chip->led_cdev);