Android 驱动之 jogball 详解

核心提示：.count = ARRAY_SIZE(hero_x_axis_gpios),.type = EV_REL,.code = REL_X,.decoded_size = 1U << ARRAY_SIZE(hero_x_axis_gpios),.map = hero_axis_map,.gpio = hero_

.count = ARRAY_SIZE(hero_x_axis_gpios),

.type = EV_REL,

.code = REL_X,

.decoded_size = 1U << ARRAY_SIZE(hero_x_axis_gpios),

.map = hero_axis_map,

.gpio = hero_x_axis_gpios,

.flags = GPIOEAF_PRINT_UNKNOWN_DIRECTION /*| GPIOEAF_PRINT_RAW | GPIOEAF_PRINT_EVENT */,

.enable_emc_protect_delay = 1 * NSEC_PER_MSEC,

}

};

X轴上的info结构体的初始化

static struct hero_axis_info hero_y_axis = {

.threshold = 1,

.info = {

.info.func = gpio_event_axis_func,

.count = ARRAY_SIZE(hero_y_axis_gpios),

.type = EV_REL,

.code = REL_Y,

.decoded_size = 1U << ARRAY_SIZE(hero_y_axis_gpios),

.map = hero_axis_map,

.gpio = hero_y_axis_gpios,

.flags = GPIOEAF_PRINT_UNKNOWN_DIRECTION /*| GPIOEAF_PRINT_RAW | GPIOEAF_PRINT_EVENT */,

.enable_emc_protect_delay = 1 * NSEC_PER_MSEC,

}

};

Y轴上的info结构体的初始化

6 备注

在android的framework的代码中识别jogball设备是识别成鼠标的特性的，不仅有坐标还是由按键的，但是驱动中并没有axis中并没

有按键，所以在注册input设备的时候要加入按键的键值。如下代码：

在drivers/input/misc/gpio_axis.c中的gpio_event_axis_func函数中

as->input_dev = input_dev;

as->info = ai;

input_set_capability(input_dev, ai->type, ai->;code);

if (ai->type == EV_ABS) {

input_set_abs_params(input_dev, ai->code, 0,

ai->decoded_size - 1, 0, 0);

}

input_set_capability(input_dev, ai->type, BT_MOUSE);

本文源码是基于hero手机kernel代码

kernel_hero/arch/arm/mach-msm/board-hero.c

下载地址 http://developer.htc.com/