硬件平台:S3C6410
操作系统:Ubuntu、windows
板子系统:Android
开发工具:jdk,ndk,eclipse
本次测试从linux内核模块编译开始,以S3C6410的pwm驱动为例。
pwm_6410.c:
#include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/poll.h> #include <linux/clk.h> #include <linux/cdev.h> #include <linux/device.h> #include <linux/miscdevice.h> #include <linux/interrupt.h> #include <plat/regs-timer.h> #include <plat/gpio-cfg.h> #include <asm/irq.h> #include <asm/io.h> #include <asm/mach/time.h> #include <asm/uaccess.h> #include <mach/map.h> #include <mach/regs-clock.h> #include <mach/regs-gpio.h> #include <mach/hardware.h> #include <mach/gpio-bank-e.h> #include <mach/gpio-bank-f.h> #include <mach/gpio-bank-k.h> #include <mach/regs-irq.h> #define DEVICE_NAME "pwm" static struct semaphore lock; static void PWM_Set_Freq( unsigned long freq ) { unsigned long tcon; unsigned long tcnt; unsigned long tcfg1; unsigned long tcfg0; unsigned long pclk; unsigned tmp; struct clk *clk_p; printk ("Freq is %d",freq); tmp = readl(S3C64XX_GPFCON);//PWM GPF15 tmp &= ~(0x3U << 30);// Timer1 tmp |= (0x2U << 30); writel(tmp, S3C64XX_GPFCON); tcon = __raw_readl(S3C_TCON); tcfg1 = __raw_readl(S3C_TCFG1); tcfg0 = __raw_readl(S3C_TCFG0); tcfg0 &= ~S3C_TCFG_PRESCALER0_MASK; tcfg0 |= (50 - 1); tcfg1 &= ~S3C_TCFG1_MUX1_MASK; tcfg1 |= S3C_TCFG1_MUX1_DIV16; __raw_writel(tcfg1, S3C_TCFG1); __raw_writel(tcfg0, S3C_TCFG0); clk_p = clk_get(NULL, "pclk"); pclk = clk_get_rate(clk_p); tcnt = (pclk/50/16)/freq; __raw_writel(tcnt, S3C_TCNTB(1)); __raw_writel(tcnt/2, S3C_TCMPB(1)); tcon &= ~(0xf << 8); tcon |= (0xb << 8); __raw_writel(tcon, S3C_TCON); tcon &= ~(2 << 8); __raw_writel(tcon, S3C_TCON); } void PWM_Stop( void ) { unsigned tmp; tmp = readl(S3C64XX_GPFCON); tmp &= ~(0x3U << 30);// set GPF15 writel(tmp, S3C64XX_GPFCON); } static int s3c64xx_pwm_open(struct inode *inode, struct file *file) { if (!down_trylock(&lock)) return 0; else return -EBUSY; } static int s3c64xx_pwm_close(struct inode *inode, struct file *file) { up(&lock); return 0; } static long s3c64xx_pwm_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { switch (cmd) { case 1: if (arg == 0) return -EINVAL; PWM_Set_Freq(arg); break; case 0: PWM_Stop(); break; } return 0; } static struct file_operations dev_fops = { .owner = THIS_MODULE, .open = s3c64xx_pwm_open, .release = s3c64xx_pwm_close, .unlocked_ioctl = s3c64xx_pwm_ioctl, }; static struct miscdevice misc = { .minor = MISC_DYNAMIC_MINOR, .name = DEVICE_NAME, .fops = &dev_fops, }; static int __init dev_init(void) { int ret; init_MUTEX(&lock); ret = misc_register(&misc); printk (DEVICE_NAME"\tinitialized\n"); return ret; } static void __exit dev_exit(void) { misc_deregister(&misc); } MODULE_LICENSE("GPL"); module_init(dev_init); module_exit(dev_exit);
Makefile添加:
obj-$(CONFIG_PWM_S3C6410) += pwm_6410.o
Kconfig添加:
config PWM_S3C6410 tristate "pwm" depends on CPU_S3C6410
make menuconfig配置内核后编译内核
make zImage后启动Android系统
ls /dev会看到名称为pwm的设备驱动
驱动已经加载好,这时候就要编写Android下的测试程序。JNI是Java Native Interface的缩写,即Java本地调用,它允许java代码和其他语言写的代码进行交互。写测试程序时使用JNI方式实现。
eclipse建立一个新的应用工程,取名为pwm,包名为com.example.pwm
默认生成的java代码:PwmActivity.java
package com.example.pwm; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; public class PwmActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_pwm); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_pwm, menu); return true; } }
添加本地方法:
package com.example.pwm; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; public class PwmActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_pwm); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_pwm, menu); return true; } public static native int pwm_set_freq(int i, int j); static { System.loadLibrary("pwm"); // 添加 C/C++动态库导入方法 } }
编辑res/layout下activity_pwm.xml
添加button控件
<Button android:id="@+id/pwm_on" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@+id/textView1" android:layout_alignLeft="@+id/textView1" android:layout_marginBottom="39dp" android:onClick="onPwmOnClicked" android:text="@string/pwm" />
编辑res/values下strings.xml
添加
<string name="pwm">pwm</string>
PwmActivity.java中添加:
public void onPwmOnClicked(View v){ pwm_set_freq(1,200); }
PwmActivity.java:
package com.example.pwm; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; public class PwmActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_pwm); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_pwm, menu); return true; } public void onPwmOnClicked(View v){ pwm_set_freq(1,200); //按下按键就输出波形 } public static native int pwm_set_freq(int i, int j); static { System.loadLibrary("pwm"); // 添加 C/C++动态库导入方法 ,这个库需要使用NDK工具编译生成。 } }
上述步骤就绪后,编译工程,再将该工程拷贝到Ubuntu下
工程目录下创建jni文件夹:
使用javah命令生成jni头文件
注意冒号后没有空格
生成的头文件:
com_example_pwm_PwmActivity.h:
/* DO NOT EDIT THIS FILE - it is machine generated */ #include <jni.h> /* Header for class com_example_pwm_PwmActivity */ #ifndef _Included_com_example_pwm_PwmActivity #define _Included_com_example_pwm_PwmActivity #ifdef __cplusplus extern "C" { #endif #undef com_example_pwm_PwmActivity_MODE_PRIVATE #define com_example_pwm_PwmActivity_MODE_PRIVATE 0L #undef com_example_pwm_PwmActivity_MODE_WORLD_READABLE #define com_example_pwm_PwmActivity_MODE_WORLD_READABLE 1L #undef com_example_pwm_PwmActivity_MODE_WORLD_WRITEABLE #define com_example_pwm_PwmActivity_MODE_WORLD_WRITEABLE 2L #undef com_example_pwm_PwmActivity_MODE_APPEND #define com_example_pwm_PwmActivity_MODE_APPEND 32768L #undef com_example_pwm_PwmActivity_MODE_MULTI_PROCESS #define com_example_pwm_PwmActivity_MODE_MULTI_PROCESS 4L #undef com_example_pwm_PwmActivity_MODE_ENABLE_WRITE_AHEAD_LOGGING #define com_example_pwm_PwmActivity_MODE_ENABLE_WRITE_AHEAD_LOGGING 8L #undef com_example_pwm_PwmActivity_BIND_AUTO_CREATE #define com_example_pwm_PwmActivity_BIND_AUTO_CREATE 1L #undef com_example_pwm_PwmActivity_BIND_DEBUG_UNBIND #define com_example_pwm_PwmActivity_BIND_DEBUG_UNBIND 2L #undef com_example_pwm_PwmActivity_BIND_NOT_FOREGROUND #define com_example_pwm_PwmActivity_BIND_NOT_FOREGROUND 4L #undef com_example_pwm_PwmActivity_BIND_ABOVE_CLIENT #define com_example_pwm_PwmActivity_BIND_ABOVE_CLIENT 8L #undef com_example_pwm_PwmActivity_BIND_ALLOW_OOM_MANAGEMENT #define com_example_pwm_PwmActivity_BIND_ALLOW_OOM_MANAGEMENT 16L #undef com_example_pwm_PwmActivity_BIND_WAIVE_PRIORITY #define com_example_pwm_PwmActivity_BIND_WAIVE_PRIORITY 32L #undef com_example_pwm_PwmActivity_BIND_IMPORTANT #define com_example_pwm_PwmActivity_BIND_IMPORTANT 64L #undef com_example_pwm_PwmActivity_BIND_ADJUST_WITH_ACTIVITY #define com_example_pwm_PwmActivity_BIND_ADJUST_WITH_ACTIVITY 128L #undef com_example_pwm_PwmActivity_CONTEXT_INCLUDE_CODE #define com_example_pwm_PwmActivity_CONTEXT_INCLUDE_CODE 1L #undef com_example_pwm_PwmActivity_CONTEXT_IGNORE_SECURITY #define com_example_pwm_PwmActivity_CONTEXT_IGNORE_SECURITY 2L #undef com_example_pwm_PwmActivity_CONTEXT_RESTRICTED #define com_example_pwm_PwmActivity_CONTEXT_RESTRICTED 4L #undef com_example_pwm_PwmActivity_RESULT_CANCELED #define com_example_pwm_PwmActivity_RESULT_CANCELED 0L #undef com_example_pwm_PwmActivity_RESULT_OK #define com_example_pwm_PwmActivity_RESULT_OK -1L #undef com_example_pwm_PwmActivity_RESULT_FIRST_USER #define com_example_pwm_PwmActivity_RESULT_FIRST_USER 1L #undef com_example_pwm_PwmActivity_DEFAULT_KEYS_DISABLE #define com_example_pwm_PwmActivity_DEFAULT_KEYS_DISABLE 0L #undef com_example_pwm_PwmActivity_DEFAULT_KEYS_DIALER #define com_example_pwm_PwmActivity_DEFAULT_KEYS_DIALER 1L #undef com_example_pwm_PwmActivity_DEFAULT_KEYS_SHORTCUT #define com_example_pwm_PwmActivity_DEFAULT_KEYS_SHORTCUT 2L #undef com_example_pwm_PwmActivity_DEFAULT_KEYS_SEARCH_LOCAL #define com_example_pwm_PwmActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L #undef com_example_pwm_PwmActivity_DEFAULT_KEYS_SEARCH_GLOBAL #define com_example_pwm_PwmActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L /* * Class: com_example_pwm_PwmActivity * Method: pwm_set_freq * Signature: (II)I */ JNIEXPORT jint JNICALL Java_com_example_pwm_PwmActivity_pwm_1set_1freq (JNIEnv *, jclass, jint, jint); #ifdef __cplusplus } #endif #endif
将头文件拷贝到jni目录下,jni目录下创建pwm.c:
#include <jni.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <android/log.h> #define LOG_TAG "PWM" //android logcat #define LOGI(...) __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__ ) #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS_ _) jint JNICALL Java_com_example_pwm_PwmActivity_pwm_1set_1freq(JNIEnv *env, jclass thiz, jint cmd, jint freq) { //函数名与头文件中的保持一致 int fd; fd = open("/dev/pwm",O_RDWR); if (fd < 0) { printf ("Open /dev/pwm file error\n"); return -1; } ioctl(fd,1,200); close (fd); return 0; }
jni目录下创建Android.mk
LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := pwm LOCAL_SRC_FILES := pwm.c LOCAL_LDLIBS := -llog LOCAL_C_INCLUDES := $(MY_ANDROID_SOURCE)/frameworks/base/core/jni/android/graphics $(MY_ANDROID_SOURCE)/external/skia/include/core $(MY_ANDROID_SOURCE)/external/skia/include/images $(MY_ANDROID_SOURCE)/frameworks/base/include $(MY_ANDROID_SOURCE)/system/core/include include $(BUILD_SHARED_LIBRARY)
命令ndk-build,如果工程目录下没有libs/armeabi,那么就创建armeabi
生成了libpwm.so就是我们在Android应用工程中需要的库文件
static { System.loadLibrary("pwm"); // 添加 C/C++动态库导入方法 }
将含有libpwm.so的工程文件从Ubuntu中考到windows,eclipse打开工程,编译生成apk
pwm.apk
在板子上安装,控制终端下输入命令:
pm install -f pwm.apk
安装成功提示success之后,点开软件,点击pwm按钮。
示波器输出200Hz百分之五十的波形,测试成功。
Android JNI用于驱动测试