Le samedi 20 février 2021 à 15:23 -0800, Dmitry Torokhov a écrit :

Hi Vincent,

Hi Dmitry, thank you for the review !

On Wed, Feb 10, 2021 at 06:33:52PM +0100, Vincent Knecht wrote:

quoted

+
+       for (i = 0; i < MAX_SUPPORTED_FINGER_NUM; i++) {
+               p = &touch_event.pkt[i];
+               /* Ignore non-pressed finger data */
+               if (p->xy_hi == 0xFF && p->x_low == 0xFF && p->y_low == 0xFF)
+                       continue;
+
+               coord.x = (((p->xy_hi & 0xF0) << 4) | p->x_low) * msg2638->prop.max_x / TPD_WIDTH;
+               coord.y = (((p->xy_hi & 0x0F) << 8) | p->y_low) * msg2638->prop.max_y / TPD_HEIGHT;
+               msg2638_report_finger(msg2638, i, &coord);

We do not scale the coordinates in the kernel. Rather we provide
resolution, if known, and min/max coordinates reported by the hardware,
and let userspace handle the rest.

Ok, will remove scaling... I was able to test it's ok by setting 
touchscreen-size-{x,y} = <2048>;

quoted

+static int __maybe_unused msg2638_suspend(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
+
+       mutex_lock(&msg2638->input_dev->mutex);
+
+       if (input_device_enabled(msg2638->input_dev))
+               msg2638_stop(msg2638);

I believe that you should power down the device only if it is not
configures as wakeup source. In fact (and I think most drivers are
wrong in this), you may want to power up the device if it is a wakeup
source and it does not have any users.

I don't know much on this subject ; from downstream code, it seems
the touchscreen supports "wakeup gestures" (like "double click",
up/down/left/right directions and some characters/letters) and apparently
an irq-gpio which would be used to wakeup.
I don't handle that currently, is it required ?