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This is Device Tree Overlays of WaveShare SpotPear 3.2" TFT LCD and WaveShare SpotPear 3.5" TFT LCD for the Raspberry PI and PI 2 using notro's FBTFT driver.

Note that the waveshare 3.5/4.0" lcd's overlay is almost same with JBTek overlay.

Update: The fbtft drivers have been absorbed into the official linux kernel tree. Step 1 can be skipped.

1.) Follow the steps on notro's wiki for installing the fbtft driver on your pi/pi2 (Your PI will not boot with the LCD attached until the right overlay is specified in /boot/config.txt)

2.) Clone my repo onto your pi

git clone https://github.com/swkim01/waveshare-dtoverlays.git

3.) According to your LCD's type, copy the overlay file waveshare32b-overlay.dtb or waveshare35b-overlay.dtb to /boot/overlays as root

In case of waveshare 3.2" LCD

sudo cp waveshare-dtoverlays/waveshare32b-overlay.dtb /boot/overlays/

or if linux 4.4 kernel or newer,

sudo cp waveshare-dtoverlays/waveshare32b-overlay.dtb /boot/overlays/waveshare32b.dtbo

In case of waveshare 3.5/4" LCD

sudo cp waveshare-dtoverlays/waveshare35a-overlay.dtb /boot/overlays/

or if linux 4.4 kernel or newer,

sudo cp waveshare-dtoverlays/waveshare35a-overlay.dtb /boot/overlays/waveshare35a.dtbo

4.) Specify this overlay file in your /boot/config.txt

dtoverlay=waveshare32b

or

dtoverlay=waveshare35a

You can configure some parameters of the lcd module like this:

dtoverlay=waveshare32b:rotate=270
dtoverlay=waveshare35a:rotate=90,swapxy=1

5.) reboot your raspberry pi

After then, you need to calibrate touch position.

Since now x server uses libinput to handle input devices instead of evdev, there are two method to calibrate/coordinate touch screen.

1.) One is to use coordination transformation matrix. You can confirm the transformation matrix property of the input device by following commands.

$ xinput list
$ xinput list-props "ADS7846 Touchscreen"

This is coordinate transformation matrix that transform from input coordinate(x, y, z) to output coordinate(X, Y, Z).

⎡ 1 0 0 ⎤
⎜ 0 1 0 ⎥
⎣ 0 0 1 ⎦

Thus to convert coordinates, you have to add the following code within the section of touchscreen in /usr/share/X11/xorg.conf.d/99-callibration.conf or 40-libinput.conf.

• in case of rotating left (counterclockwise 90 degree),

    ⎡ 0 -1 1 ⎤ 
    ⎜ 1  0 0 ⎥ 
    ⎣ 0  0 1 ⎦ 
  

   Option "TransformationMatrix" "0 -1 1 1 0 0 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 0 -1 1 1 0 0 0 0 1
  

• in case of rotating right (clockwise 90 degree),

    ⎡ 0 1 0 ⎤ 
    ⎜-1 0 1 ⎥ 
    ⎣ 0 0 1 ⎦ 
  

   Option "TransformationMatrix" "0 1 0 -1 0 1 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 0 1 0 -1 0 1 0 0 1
  

• in case of inverting rotate (clockwise 180 degree),

    ⎡-1  0 1 ⎤ 
    ⎜ 0 -1 1 ⎥ 
    ⎣ 0  0 1 ⎦ 
  

   Option "TransformationMatrix" "-1 0 1 0 -1 1 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' -1 0 1 0 -1 1 0 0 1
  

• in case of inverting x,

    ⎡-1 0 1 ⎤ 
    ⎜ 0 1 1 ⎥ 
    ⎣ 0 0 1 ⎦ 
  

   Option "TransformationMatrix" "-1 0 1 0 1 0 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' -1 0 1 0 1 0 0 0 1
  

• in case of inverting y,

    ⎡ 1  0 0 ⎤ 
    ⎜ 0 -1 1 ⎥ 
    ⎣ 0  0 1 ⎦ 
  

   Option "TransformationMatrix" "1 0 0 0 -1 1 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 1 0 0 0 -1 1 0 0 1
  

• in case of swapping x and y,

    ⎡ 0 1 0 ⎤ 
    ⎜ 1 0 0 ⎥ 
    ⎣ 0 0 1 ⎦ 
  

   Option "TransformationMatrix" "0 1 0 1 0 0 0 0 1"
  

  or execute the following code.

   xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 0 1 0 1 0 0 0 0 1
  

2.) The other method is to reuse evdev. The detailed step is as follows.

• Install evdev package.

$ sudo apt-get install xserver-xorg-input-evdev

• Make sure that /etc/X11/xorg.conf.d is empty.
• Modify /usr/share/X11/xorg.conf.d/40-libinput.conf in the last section change the driver to evdev.

Section "InputClass"
        Identifier "libinput touchscreen catchall"
        MatchIsTouchscreen "on"
        MatchDevicePath "/dev/input/event*"
        Driver "evdev"
EndSection

• Calibrate touchscreen as to FBTFT wiki and/or make /usr/share/X11/xorg.conf.d/99-ads7846-cal.conf.