1.定义的结构体继承input_dev - struct bma150_data {
- struct i2c_client *bma150_client;
- struct bma150_platform_data *platform_data;
- int IRQ;
- atomic_t delay;
- unsigned char mode;
- struct input_dev *input;
- struct bma150acc value;
- struct mutex value_mutex;
- struct mutex mode_mutex;
- struct delayed_work work;
- struct work_struct irq_work;
- };
2.给input_dev指定名字和总线类型,对input事件类型可以参考下面代码
EV_MSC 类型参考下面的
set_bit(EV_MSC, dev->evbit);
set_bit(MSC_RAW, dev->mscbit);
EV_ABS类型参考下面的
input->evbit[0] = BIT(EV_ABS);
input->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_Z);
- input_set_capability实际调用的也是__set_bit,
input_set_abs_params调用实际上也是set_bit,对于参数(dev,axis,min,max,fuzz,flat) fuzz有滤波作用,min,max代表范围,axis表示了坐标轴,flat暂时不知到用途
3.通过input_register_device(dev)注册input设备
- static int bma150_input_init(struct bma150_data *bma150)
- {
- struct input_dev *dev;
- int err;
-
- dev = input_allocate_device();
- if (!dev)
- return -ENOMEM;
- dev->name = SENSOR_NAME;
- dev->id.bustype = BUS_I2C;
-
- input_set_capability(dev, EV_ABS, ABS_MISC);
- input_set_abs_params(dev, ABS_X, ABSMIN_2G, ABSMAX_2G, 0, 0);
- input_set_abs_params(dev, ABS_Y, ABSMIN_2G, ABSMAX_2G, 0, 0);
- input_set_abs_params(dev, ABS_Z, ABSMIN_2G, ABSMAX_2G, 0, 0);
- input_set_drvdata(dev, bma150);
-
- err = input_register_device(dev);
- if (err < 0) {
- input_free_device(dev);
- return err;
- }
- bma150->input = dev;
-
- return 0;
- }
据说可以指定input号
dev->phys = "bma150/input0";
dev->id.bustype = BUS_HOST;
4.在中断函数或者工作队列中调用input_event上报事件
static inline void input_report_abs(struct input_dev *dev, unsigned int code, int value)
{
input_event(dev, EV_ABS, code, value);
}
input_event函数说明,input调用input_handle_event
对各种事件类型的处理主要体现在input_handle_event函数上
- static void input_handle_event(struct input_dev *dev,
- unsigned int type, unsigned int code, int value)
- {
- int disposition = INPUT_IGNORE_EVENT;//忽略事件
-
- switch (type) {
-
- case EV_SYN:
- switch (code) {
- case SYN_CONFIG:
- disposition = INPUT_PASS_TO_ALL;//传给设备和handle处理
- break;
-
- case SYN_REPORT:
- if (!dev->sync) {
- dev->sync = true;
- disposition = INPUT_PASS_TO_HANDLERS;//传给handle处理 同步事件
- }
- break;
- case SYN_MT_REPORT:
- dev->sync = false;
- disposition = INPUT_PASS_TO_HANDLERS;//传给handle处理 多点触摸
- break;
- }
- break;
-
- case EV_KEY:
- if (is_event_supported(code, dev->keybit, KEY_MAX) &&
- !!test_bit(code, dev->key) != value) {
-
- if (value != 2) {
- __change_bit(code, dev->key);
- if (value)
- input_start_autorepeat(dev, code);
- else
- input_stop_autorepeat(dev);
- }
-
- disposition = INPUT_PASS_TO_HANDLERS;
- }
- break;
-
- case EV_SW://耳机事件
- if (is_event_supported(code, dev->swbit, SW_MAX) &&
- !!test_bit(code, dev->sw) != value) {
-
- __change_bit(code, dev->sw);
- disposition = INPUT_PASS_TO_HANDLERS;
- }
- break;
-
- case EV_ABS:
- if (is_event_supported(code, dev->absbit, ABS_MAX))
- disposition = input_handle_abs_event(dev, code, &value);//这里调用的input_handle_abs_event会将上次值和这次值相同的事件过滤掉
-
- break;
-
- case EV_REL:
- if (is_event_supported(code, dev->relbit, REL_MAX) && value)
- disposition = INPUT_PASS_TO_HANDLERS;
-
- break;
-
- case EV_MSC:
- if (is_event_supported(code, dev->mscbit, MSC_MAX))
- disposition = INPUT_PASS_TO_ALL;
-
- break;
-
- case EV_LED:
- if (is_event_supported(code, dev->ledbit, LED_MAX) &&
- !!test_bit(code, dev->led) != value) {
-
- __change_bit(code, dev->led);
- disposition = INPUT_PASS_TO_ALL;
- }
- break;
-
- case EV_SND:
- if (is_event_supported(code, dev->sndbit, SND_MAX)) {
-
- if (!!test_bit(code, dev->snd) != !!value)
- __change_bit(code, dev->snd);
- disposition = INPUT_PASS_TO_ALL;
- }
- break;
-
- case EV_REP:
- if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
- dev->rep[code] = value;
- disposition = INPUT_PASS_TO_ALL;
- }
- break;
-
- case EV_FF:
- if (value >= 0)
- disposition = INPUT_PASS_TO_ALL;
- break;
-
- case EV_PWR:
- disposition = INPUT_PASS_TO_ALL;
- break;
- }
-
- if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
- dev->sync = false;
-
- if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
- dev->event(dev, type, code, value);
-
- if (disposition & INPUT_PASS_TO_HANDLERS)
- input_pass_event(dev, type, code, value);
- }
-
- /**
- * input_event() - report new input event
- * @dev: device that generated the event
- * @type: type of the event
- * @code: event code
- * @value: value of the event
- *
- * This function should be used by drivers implementing various input
- * devices to report input events. See also input_inject_event().
- *
- * NOTE: input_event() may be safely used right after input device was
- * allocated with input_allocate_device(), even before it is registered
- * with input_register_device(), but the event will not reach any of the
- * input handlers. Such early invocation of input_event() may be used
- * to 'seed' initial state of a switch or initial position of absolute
- * axis, etc.
- */
- void input_event(struct input_dev *dev,
- unsigned int type, unsigned int code, int value)
- {
- unsigned long flags;
-
- if (is_event_supported(type, dev->evbit, EV_MAX)) {
-
- spin_lock_irqsave(&dev->event_lock, flags);
- add_input_randomness(type, code, value);
- input_handle_event(dev, type, code, value);
- spin_unlock_irqrestore(&dev->event_lock, flags);
- }
- }
- EXPORT_SYMBOL(input_event);
- static int input_handle_abs_event(struct input_dev *dev,
- unsigned int code, int *pval)
- {
- bool is_mt_event;
- int *pold;
-
- if (code == ABS_MT_SLOT) {//多点触摸信号??
- /*
- * "Stage" the event; we'll flush it later, when we
- * get actual touch data.
- */
- if (*pval >= 0 && *pval < dev->mtsize)
- dev->slot = *pval;
-
- return INPUT_IGNORE_EVENT;
- }
-
- is_mt_event = code >= ABS_MT_FIRST && code <= ABS_MT_LAST;//多点触摸事件值
-
- if (!is_mt_event) {//不是多点触摸值,旧将上次值保存在pold里面
- pold = &dev->absinfo[code].value;
- } else if (dev->mt) {
- struct input_mt_slot *mtslot = &dev->mt[dev->slot];
- pold = &mtslot->abs[code - ABS_MT_FIRST];
- } else {
- /*
- * Bypass filtering for multi-touch events when
- * not employing slots.
- */
- pold = NULL;
- }
-
- if (pold) {
- *pval = input_defuzz_abs_event(*pval, *pold,//fuzz为0时,返回值为pold本身
- dev->absinfo[code].fuzz);//这里fuzz是在2中设置类型时传入的参数input_set_abs_params(dev,axis,min,max.fuzz,flat)
- if (*pold == *pval)
- return INPUT_IGNORE_EVENT;
-
- *pold = *pval;
- }
-
- /* Flush pending "slot" event */
- if (is_mt_event && dev->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
- input_abs_set_val(dev, ABS_MT_SLOT, dev->slot);
- input_pass_event(dev, EV_ABS, ABS_MT_SLOT, dev->slot);
- }
-
- return INPUT_PASS_TO_HANDLERS;
- }
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