topic Re: Led for Button Touch in i.MX Processors

Led for Button Touch

dinhbang — Tue, 22 Apr 2014 10:35:12 GMT

Hi everyone,

I have integrated touch for my custom board, and i need integrate leds for button touch. I have created dev file button-backlight in /sys/class/leds/ and add code as below to imx/lights/fsl_lights.c in HAL:

char const*const KEYBOARD_FILE
        = "/sys/class/leds/button-backlight/brightness";
...

static int
set_light_buttons(struct light_device_t *dev,
    struct light_state_t const *state)
{
    int err = 0;
    int on = is_lit(state);
    pthread_mutex_lock(&g_lock);
    err = write_int(KEYBOARD_FILE, on ? 255 : 0);
    pthread_mutex_unlock(&g_lock);


    return err;


}
...
if (0 == strcmp(LIGHT_ID_BACKLIGHT, name))
        set_light = set_light_backlight;
    else if (0 == strcmp(LIGHT_ID_KEYBOARD, name))
        set_light = set_light_keyboard;
    else if (0 == strcmp(LIGHT_ID_BUTTONS, name))
        set_light = set_light_buttons;
    else if (0 == strcmp(LIGHT_ID_BATTERY, name))
        set_light = set_light_battery;
    else if (0 == strcmp(LIGHT_ID_NOTIFICATIONS, name))
        set_light = set_light_notification;
    else if (0 == strcmp(LIGHT_ID_ATTENTION, name))
        set_light = set_light_attention;
    else
        return -EINVAL;

But it do not work, i think platform of FSL is using LIGHT_ID_BATTERY and LIGHT_ID_BACKLIGHT, and I do not know where to configure for LIGHT_ID_BUTTONS. If anyone has solution for this issue, let me know, thank you very much!

Re: Led for Button Touch

igorpadykov — Wed, 23 Apr 2014 03:51:31 GMT

Hi Dinh

what processor and what BSP are you using ?

Re: Led for Button Touch

dinhbang — Wed, 23 Apr 2014 07:49:12 GMT

Hi chipexpert, thanks for reply, i use imx6q and BSP is android 4.2

Re: Re: Led for Button Touch

jamesbone — Mon, 05 May 2014 20:18:18 GMT

Dear Dinh,

Let me give you some resume about how the inputs are working in Android, I think you should use the events to call the led ligth from there. Please see the attach

Have a great day,
Jaime

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