support for waveshare 4inch display (rev A)

diff --git a/modules/display_wsLCD4.mk b/modules/display_wsLCD4.mk
new file mode 100644 (file)
index 0000000..7c32cf5
--- /dev/null
+++ b/modules/display_wsLCD4.mk
@@ -0,0 +1,77 @@
+PACKAGES += xserver-xorg-input-evdev xinput xinput-calibrator
+
+define RPICONFIG +=
+
+### Waveshare 4 Inch Display ###
+hdmi_force_hotplug=1
+dtparam=i2c_arm=on
+dtparam=spi=on
+enable_uart=1
+dtoverlay=waveshare35a
+# dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax=3900
+hdmi_group=2
+hdmi_mode=1
+hdmi_mode=87
+hdmi_cvt 430 320 60 6 0 0 0
+hdmi_drive=2
+display_rotate=0
+endef
+
+export display_wsLCD4_cfg display_wsLCD4_rotation
+
+define display_wsLCD4_cfg :=
+Section "InputClass"
+       Identifier      "calibration"
+       MatchProduct    "ADS7846 Touchscreen"
+       Option  "Calibration"   "3950 172 3871 194"
+       Option  "SwapAxes"      "1"
+       Option  "EmulateThirdButton"    "1"
+       Option  "EmulateThirdButtonTimeout"     "1000"
+       Option  "EmulateThirdButtonMoveThreshold"       "300"
+
+       # Identifier "evdev touchscreen catchall"
+       # MatchIsTouchscreen "on"
+       # Option  "Calibration"   "200 3950 250 4000"
+       # MatchDevicePath "/dev/input/event*"
+       # Driver "evdev"
+EndSection
+endef
+
+define display_wsLCD4_rotation :=
+# Keep touch matrix rotated in accordance with screen rotation
+while sleep 3; do
+  oldrotate="$${rotate}"
+  rotate="$$(xrandr |grep primary)"
+  rotate="$${rotate#*+0+0 }"
+  rotate="$${rotate% (*}"
+
+  [ "$${oldrotate}" = "$${rotate}" ] || case $$rotate in
+    left)     xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 0 -1 1  1 0 0  0 0 1;;
+    right)    xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 0 1 0  -1 0 1  0 0 1;;
+    inverted) xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' -1 0 1  0 -1 1  0 0 1;;
+    *)        xinput set-prop 'ADS7846 Touchscreen' 'Coordinate Transformation Matrix' 1 0 0  0 1 0  0 0 1;;
+  esac
+done &
+endef
+
+.PHONY: _display_wsLCD4
+_config: _display_wsLCD5 ${CFGROOT}/boot/waveshare35a.dtbo
+_display_wsLCD4: ${CFGROOT} _copy _mount
+       # Rough touch calibration
+       mkdir -p "$${CFGROOT}/usr/share/X11/xorg.conf.d/"
+       printf '%s\n' "$${display_wsLCD4_cfg}" >"$${CFGROOT}/usr/share/X11/xorg.conf.d/45-evdev.conf"
+       # Resolution / Rotation stuff
+       mkdir -p "$${CFGROOT}/etc/X11/Xsession.d/"
+       printf 'xrandr --size 480x320\n' >"$${CFGROOT}/etc/X11/Xsession.d/10display_resolution"
+       printf '%s\n' "$$display_wsLCD4_rotation" >"$${CFGROOT}/etc/X11/Xsession.d/20touch_rotation"
+       # Correct DPI scaling, although application support is mediocre
+       mkdir -p "$${CFGROOT}/etc/X11/Xresources/"
+       printf 'Xft.dpi: 144\n' >"$${CFGROOT}/etc/X11/Xresources/dpi_resolution"
+       # Workaround for applications that do not handle DPI scaling correctly
+       -sed -i 's;^Exec=;Exec=env GDK_DPI_SCALE=.5 ;' \
+         $${CFGROOT}/usr/share/applications/chromium*.desktop \
+         $${CFGROOT}/usr/share/applications/firefox*.desktop \
+         $${CFGROOT}/usr/share/applications/exo-web-browser.desktop
+
+${CFGROOT}/boot/waveshare35a.dtbo: modules/waveshare35a-overlay.dtb
+       cp "$<" "$@"

diff --git a/modules/waveshare35a-overlay.dtb b/modules/waveshare35a-overlay.dtb
new file mode 100644 (file)
index 0000000..9f082e4
Binary files /dev/null and b/modules/waveshare35a-overlay.dtb differ