Linux内核学习实践之GPIO面板按键

来源：互联网发布：什么是独立域名编辑：程序博客网时间：2024/06/06 04:07

说明：本分析基于AM6C平台Linux3.0.8内核，其他内核版本仅供参考。

一、platform设备注册的按键映射

common/customer/boards/board-m6tv-h32.c

static struct adc_key adc_kp_key[] = {  {KEY_UP,    "vol+",           CHAN_0, 821,  60},//k3  //change by tank@tcl.com  {KEY_LEFT,     "vol-",           CHAN_0, 648,  60},//k4  {KEY_UP,       "ch+",            CHAN_0, 464,  60},//k5  {KEY_DOWN,     "ch-",            CHAN_0, 247,  60},//k6  {KEY_ENTER,    "power",          CHAN_0, 28,    60},//k7}/*struct adc_key{  int code;/* input key code */  unsigned char *name;  int chan;  int value;/* voltage/3.3v * 1023 */  int tolerance;  int gpio_code; };*/static struct adc_kp_platform_data adc_kp_pdata = {  .key = &adc_kp_key[0],  .key_num = ARRAY_SIZE(adc_kp_key),};static struct platform_device adc_kp_device = {  .name = "m1-adckp",  .id = 0,  .num_resources = 0,  .resource = NULL,  .dev = {    .platform_data = &adc_kp_pdata,  }};platform_add_devices(platform_devs, ARRAY_SIZE(platform_devs));static struct platform_device  *platform_devs[] = {  ......  &adc_kp_device,  ......}

二、驱动

static struct platform_driver kp_driver = {  .probe      = kp_probe,  .remove     = kp_remove,  .suspend    = NULL,  .resume     = NULL,  .driver     = {    .name   = "m1-adckp",  },};static int __devinit kp_init(void){  printk(KERN_INFO "ADC Keypad Driver init.\n");  return platform_driver_register(&kp_driver);}module_init(kp_init);//////////////////////////////static int __devinit kp_probe(struct platform_device *pdev){  struct adc_kp_platform_data *pdata = pdev->dev.platform_data;  kp = kzalloc(sizeof(struct kp), GFP_KERNEL);  platform_set_drvdata(pdev, kp);  kp->input = input_dev;  kp->cur_keycode = 0;  kp->tmp_code = 0;  kp->count = 0;//注册工作队列update_work_func  INIT_WORK(&(kp->work_update), update_work_func);//注册时钟中断kp_timer_sr；该时钟中断处理程序的底半部为上处工作队列。//该底半部由工作队列调度，因此、运行与进程上下文  setup_timer(&kp->timer, kp_timer_sr, (unsigned int)kp);/*void kp_timer_sr(unsigned long data){  struct kp *kp_data=(struct kp *)data;  schedule_work(&(kp_data->work_update));  mod_timer(&kp_data->timer,jiffies+msecs_to_jiffies(10));}*/  mod_timer(&kp->timer, jiffies+msecs_to_jiffies(100));////////////////////////////  kp->key = pdata->key;  kp->key_num = pdata->key_num;  adckp_set_keypad(kp);////////////////////////////}