1. chapter 7-Android HAL
中国科学技术大学软件学院

2. Android Architecture 2

3. Android device Driver 3

4. Android device Driver 4

5. Android device Driver #include "s3c6410_leds_hal.h"
#include "leds_hal_define.h"
static unsigned char mem[5];
static int major = S3C6410_LEDS_MAJOR;
static int minor = S3C6410_LEDS_MINOR;
static dev_t dev_number;
static struct class *leds_class = NULL;
static int bytes_to_int(unsigned char buf[], int start) {
int n = 0;
n = ((int) buf[start]) << 24 | ((int) buf[start + 1]) << 16
| ((int) buf[start + 2]) << 8 | ((int) buf[start + 3]);
return n; } 5

6. Android device Driver
static void int_to_bytes(int n, unsigned char buf[], int start) {
buf[start] = n >> 24;
buf[start + 1] = n >> 16;
buf[start + 2] = n >> 8;
buf[start + 3] = n; } 6

7. Android device Driver
static ssize_t s3c6410_leds_hal_write(struct file *file, const char __user *buf,size_t count, loff_t *ppos) {
if (copy_from_user(mem, buf, 5))
return -EFAULT; }
else
int gpm_type = mem[0];
switch (gpm_type)
case S3C6410_LEDS_HAI_WRITE_GPMCON:
iowrite32(bytes_to_int(mem, 1), S3C64XX_GPMCON);
break;
case S3C6410_LEDS_HAI_WRITE_GPMPUD:
iowrite32(bytes_to_int(mem, 1), S3C64XX_GPMPUD);
case S3C6410_LEDS_HAI_WRITE_GPMDAT:
iowrite32(bytes_to_int(mem, 1), S3C64XX_GPMDAT);
return 5; 7

8. Android device Driver
static ssize_t s3c6410_leds_hal_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos) {
int gpm_type = mem[0];
int gpm_value = 0;
switch (gpm_type)
case S3C6410_LEDS_HAI_READ_GPMCON:
gpm_value = ioread32(S3C64XX_GPMCON);
break;
case S3C6410_LEDS_HAI_READ_GPMPUD:
gpm_value = ioread32(S3C64XX_GPMPUD);
case S3C6410_LEDS_HAI_READ_GPMDAT:
gpm_value = ioread32(S3C64XX_GPMDAT); }
int_to_bytes(gpm_value, mem, 1);
if (copy_to_user(buf, (void*) mem, 5))
return -EFAULT;
return 5; 8

9. Android device Driver static struct file_operations dev_fops =
{ .owner = THIS_MODULE, .read = s3c6410_leds_hal_read, .write =
s3c6410_leds_hal_write };
static struct cdev leds_cdev; 9

10. Android device Driver （/dev/s3c6410_leds_hal）
static int leds_create_device(void) {
int ret = 0;
int err = 0;
cdev_init(&leds_cdev, &dev_fops);
leds_cdev.owner = THIS_MODULE;
if (major > 0)
dev_number = MKDEV(major, minor);
err = register_chrdev_region(dev_number, DEVICE_COUNT, DEVICE_NAME);
if (err < 0)
printk(KERN_WARNING "register_chrdev_region() failed\n");
return err; } 10

11. Android device Driver else {
err = alloc_chrdev_region(&leds_cdev.dev, 10, DEVICE_COUNT,
DEVICE_NAME);
if (err < 0)
printk(KERN_WARNING "alloc_chrdev_region() failed\n");
return err; }
major = MAJOR(leds_cdev.dev);
minor = MINOR(leds_cdev.dev);
//dev_number = MKDEV(major, minor);
dev_number = leds_cdev.dev;
ret = cdev_add(&leds_cdev, dev_number, DEVICE_COUNT);
leds_class = class_create(THIS_MODULE, DEVICE_NAME);
device_create(leds_class, NULL, dev_number, NULL, DEVICE_NAME);
return ret; 11

12. Android device Driver static int leds_init(void) { int ret;
ret = leds_create_device();
printk(DEVICE_NAME"\tinitialized\n");
printk(KERN_EMERG"tes1fdddfs1t\n");
return ret; }
static void leds_destroy_device(void) {
device_destroy(leds_class, dev_number);
if (leds_class)
class_destroy(leds_class);
unregister_chrdev_region(dev_number, DEVICE_COUNT);
return;
static void leds_exit(void)
leds_destroy_device();
printk(DEVICE_NAME"\texit!\n");
module_init(leds_init);
module_exit(leds_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("ustc"); 12

13. Android device Driver-example
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <jni.h>
#include <leds_hal.h>
//led_control_device_t
struct led_control_device_t *led_hal_device = NULL;
static jboolean led_setOn(JNIEnv* env, jobject thiz, jint led) {
LOGI("Led HAL JNI: led_setOn() is invoked.");
if (led_hal_device == NULL)
LOGI("Led HAL JNI: led_hal_device was not fetched correctly.");
return -1; }
else
{ //led_control_device_t.set_on
return led_hal_device->set_on(led_hal_device, led);
LedHalService.app 13

14. Android device Driver-example
static jboolean led_setOff(JNIEnv* env, jobject thiz, jint led) {
LOGI("Led HAL JNI: led_setOff() is invoked.");
if (led_hal_device == NULL)
LOGI("Led HAL JNI: led_hal_device was not fetched correctly.");
return -1; }
else
return led_hal_device->set_off(led_hal_device, led); 14

15. Android device Driver-example
static inline int led_control_open(const struct hw_module_t* module, struct led_control_device_t** device) {
return module->methods->open(module, LED_HARDWARE_MODULE_ID,
(struct hw_device_t**) device);
}static jboolean led_init(JNIEnv *env, jclass clazz)
led_module_t* module;
LOGE("**********start find hal *********");
LOGE(LED_HARDWARE_MODULE_ID);
if (hw_get_module(LED_HARDWARE_MODULE_ID, (const hw_module_t**) &module) == 0)
LOGI("LedService JNI: LED Stub found.");
if (led_control_open(&module->hw_module, &led_hal_device) == 0)
LOGI("LedService JNI: Got Stub operations.");
return 0; }
LOGE("LedService JNI: Get Stub operations failed.");
return -1; 15

16. Android device Driver-example
static const JNINativeMethod methods[] = {
{ "_init", "()Z", (void *) led_init },
{ "_set_on", "(I)Z", (void *) led_setOn },
{ "_set_off", "(I)Z", (void *) led_setOff }, };
int register_led_hal_jni(JNIEnv* env)
static const char* const kClassName = "mobile/android/leds/hal/service/LedHalService";
jclass clazz;
clazz = env->FindClass(kClassName);
if (clazz == NULL)
LOGE("Can't find class %s\n", kClassName);
return -1; }
if (env->RegisterNatives(clazz, methods,
sizeof(methods) / sizeof(methods[0])) != JNI_OK)
LOGE("Failed registering methods for %s\n", kClassName);
return 0; 16

17. jint JNI_OnLoad(JavaVM* vm, void* reserved){
JNIEnv* env = NULL;
jint result = -1;
if (vm->GetEnv((void**) &env, JNI_VERSION_1_4) != JNI_OK)
LOGE("GetEnv failed!");
return result; }
register_led_hal_jni(env);
return JNI_VERSION_1_4; 17

18. Android device Driver-example
package mobile.android.s3c6410.leds.hal.java;
import mobile.android.leds.hal.service.LedHalService;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
public class S3C6410LedHalMain extends Activity {
private CheckBox[] cbStrLeds = new CheckBox[4];
LedHalService ledHalService = LedHalService.getInstance();
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
cbStrLeds[0] = (CheckBox) findViewById(R.id.checkbox_str_led1);
cbStrLeds[1] = (CheckBox) findViewById(R.id.checkbox_str_led2);
cbStrLeds[2] = (CheckBox) findViewById(R.id.checkbox_str_led3);
cbStrLeds[3] = (CheckBox) findViewById(R.id.checkbox_str_led4); }
public void onClick_ControlStr(View view)
String str = "";
for (int i = 0; i < 4; i++)
if (cbStrLeds[i].isChecked())
ledHalService.setOn(i);
else
ledHalService.setOff(i); 18

19. 19

20. 20

21. thank you !