Re: Touch screen problem

I have added another printk

printk(KERN_INFO "compute touch pressure resistance using equation #2 \n"); printk(KERN_INFO "z1=%d, z2=%d, x=%d, y=%d, x_plate_ohms=%d \n", z1, z2, x, y, ts->x_plate_ohms); Rt = z2; Rt -= z1; Rt *= x; Rt *= ts->x_plate_ohms; Rt /= z1; Rt = (Rt + 2047) >> 12;

the output:

<6>[ 49.927917] ads7846_report_state <6>[ 49.931304] compute touch pressure resistance using equation #2 <6>[ 49.937652] z1=8191, z2=8191, x=8191, y=8191, x_plate_ohms=180 <6>[ 49.943908] Rt 0 <6>[ 49.945922] not reporting. Rt=0 <6>[ 49.959045] ads7846_report_state <6>[ 49.962432] compute touch pressure resistance using equation #2 <6>[ 49.968749] z1=8191, z2=8191, x=8191, y=8191, x_plate_ohms=180 <6>[ 49.975006] Rt 0

Thanks Francesco

2012/2/15 Francesco Sarasini sarasini@gmail.com

Hi added the printk. this is my code

static void ads7846_report_state(struct ads7846 *ts) { struct ads7846_packet *packet = ts->packet; unsigned int Rt; u16 x, y, z1, z2;

/* added for debug */
printk(KERN_INFO "ads7846_report_state\n");

/*
 * ads7846_get_value() does in-place conversion (including byte swap)
 * from on-the-wire format as part of debouncing to get stable
 * readings.
 */
if (ts->model == 7845) {
    x = *(u16 *)packet->tc.x_buf;
    y = *(u16 *)packet->tc.y_buf;
    z1 = 0;
    z2 = 0;
} else {
    x = packet->tc.x;
    y = packet->tc.y;
    z1 = packet->tc.z1;
    z2 = packet->tc.z2;
}

/* range filtering */
if (x == MAX_12BIT)
    x = 0;

if (ts->model == 7843) {
    Rt = ts->pressure_max / 2;
} else if (ts->model == 7845) {
    if (get_pendown_state(ts)) {
        Rt = ts->pressure_max / 2;
    } else {
        /* added for debug */
        printk(KERN_INFO "cannot get pendown state \n");
        Rt = 0;
    }
    dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
} else if (likely(x && z1)) {
    /* compute touch pressure resistance using equation #2 */
    /* added for debug */
    printk(KERN_INFO "compute touch pressure resistance using equation

#2 \n"); Rt = z2; Rt -= z1; Rt *= x; Rt *= ts->x_plate_ohms; Rt /= z1; Rt = (Rt + 2047) >> 12; } else { /* added for debug */ printk(KERN_INFO "ts model ? %d \n", ts->model); Rt = 0; } /* added for debug */ printk(KERN_INFO "Rt %d \n", Rt);

/*
 * Sample found inconsistent by debouncing or pressure is beyond
 * the maximum. Don't report it to user space, repeat at least
 * once more the measurement
 */
if (packet->tc.ignore || Rt > ts->pressure_max) {
    /* added for debug */
    printk(KERN_INFO "Ignored %d pressure %d \n", packet->tc.ignore,

Rt);

    dev_vdbg(&ts->spi->dev, "ignored %d pressure %d \n",
         packet->tc.ignore, Rt);
    return;
}

/*
 * Maybe check the pendown state before reporting. This discards
 * false readings when the pen is lifted.
 */
if (ts->penirq_recheck_delay_usecs) {
    udelay(ts->penirq_recheck_delay_usecs);
    if (!get_pendown_state(ts)) {
        /* added for debug */
        printk(KERN_INFO "cannot get pendown state \n");
        Rt = 0;
    }
}

/*
 * NOTE: We can't rely on the pressure to determine the pen down
 * state, even this controller has a pressure sensor. The pressure
 * value can fluctuate for quite a while after lifting the pen and
 * in some cases may not even settle at the expected value.
 *
 * The only safe way to check for the pen up condition is in the
 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 */
if (Rt) {
    struct input_dev *input = ts->input;

    if (ts->swap_xy)
        swap(x, y);

    if (!ts->pendown) {
        input_report_key(input, BTN_TOUCH, 1);
        ts->pendown = true;
        dev_vdbg(&ts->spi->dev, "DOWN\n");
    }

    /* added for debug */
    printk(KERN_INFO "input_report_abs x: %d, y: %d \n", x, y);


    input_report_abs(input, ABS_X, x);
    input_report_abs(input, ABS_Y, y);
    input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);

    input_sync(input);
    dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
} else {
    /* added for debug */
    printk(KERN_INFO "not reporting. Rt=%d \n", Rt);
}

}

and the output after touching the screen

<6>[ 59.531036] ads7846_report_state <6>[ 59.534423] compute touch pressure resistance using equation #2 <6>[ 59.540771] Rt 0 <6>[ 59.542785] not reporting. Rt=0 <6>[ 59.553497] ads7846_report_state <6>[ 59.556884] compute touch pressure resistance using equation #2 <6>[ 59.563201] Rt 0 <6>[ 59.565216] not reporting. Rt=0 <6>[ 59.577087] ads7846_report_state <6>[ 59.580474] compute touch pressure resistance using equation #2 <6>[ 59.586791] Rt 0 <6>[ 59.588836] not reporting. Rt=0 <6>[ 59.850494] ads7846_report_state <6>[ 59.853881] compute touch pressure resistance using equation #2 <6>[ 59.860198] Rt 0 <6>[ 59.862213] not reporting. Rt=0

Thanks Francesco

2012/2/15 Francesco Sarasini sarasini@gmail.com

...

Thank you. My code base is Linaro Android. I will add the printk to the code

Francesco

2012/2/15 Bharathi Subramanian bharathi.list@gmail.com

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On Tue, Feb 14, 2012 at 7:48 PM, Francesco Sarasini sarasini@gmail.com wrote:

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Please add printk to show the value of x, y, before and after the OMAP3EVM macro. That will give better idea about the touchevent.

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I'm sorry, where is the OMAP3EVM macro?

Oops. I hope, it is in EVM Code. For BB-xM, it might be different.

The following set of commands are responsible for sending the co-ordinates to user space. You have to add printk before this and check.

input_report_abs(input, ABS_X, x); input_report_abs(input, ABS_Y, y); input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);

Can you share info about code base (Rowboat/Linaro) ?

Bye :)

Bharathi Subramanian