pitft: Add basic support for PiTFT

Add basic support for PiTFT display by using device-trees.

In order get it working below configurations must be active in
local.conf:

MACHINE_FEATURES += "pitft"
 - This will enable SPI bus and i2c device-trees, it will also setup
   framebuffer for console and x server on PiTFT.

[Support #70]

Signed-off-by: Petter Mabäcker <petter@technux.se>
Signed-off-by: Andrei Gherzan <andrei@gherzan.ro>

README

@@ -28,6 +28,7 @@ Contents:
     3.K. Device tree support
     3.L. Enable SPI bus
     3.M. Enable I2C
+    3.N. Enable PiTFT support
 4. Extra apps
     4.A. omxplayer
 5. Board Configuration
@@ -213,6 +214,18 @@ ENABLE_SPI_BUS = "1"
 When using device tree kernels, set this variable to enable I2C
 ENABLE_I2C = "1"
 
+3.N. Enable PiTFT support
+=========================
+Basic support for using PiTFT screens can be enabled by adding
+below in local.conf:
+
+MACHINE_FEATURES += "pitft"
+  - This will enable SPI bus and i2c device-trees, it will also setup
+    framebuffer for console and x server on PiTFT.
+
+NOTE: To get this working the overlay for the PiTFT model must be build,
+      added and specified as well (dtoverlay=<driver> in config.txt)
+
 
 4. Extra apps
 =============

recipes-bsp/bootfiles/rpi-config_git.bb

@@ -15,6 +15,8 @@ S = "${WORKDIR}/git"
 
 PR = "r4"
 
+PITFT="${@bb.utils.contains("MACHINE_FEATURES", "pitft", "1", "0", d)}"
+
 inherit deploy
 
 do_deploy() {
@@ -71,12 +73,12 @@ do_deploy() {
     fi
 
     # SPI bus support
-    if [ -n "${ENABLE_SPI_BUS}" ]; then
+    if [ -n "${ENABLE_SPI_BUS}" ] || [ "${PITFT}" = "1" ]; then
         echo "# Enable SPI bus" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
         echo "dtparam=spi=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
     fi
 
-    if [ -n "${ENABLE_I2C}" ]; then
+    if [ -n "${ENABLE_I2C}" ] || [ "${PITFT}" = "1" ]; then
         echo "# Enable I2C" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
         echo "dtparam=i2c1=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
         echo "dtparam=i2c_arm=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt

recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf.d/99-pitft.conf

@@ -0,0 +1,5 @@
+Section "Device"
+    Identifier "Adafruit PiTFT"
+    Driver "fbdev"
+    Option "fbdev" "/dev/fb1"
+EndSection

recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend

@@ -1,10 +1,17 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
 
-SRC_URI_append_rpi = " file://xorg.conf.d/10-evdev.conf "
+SRC_URI_append_rpi = " file://xorg.conf.d/10-evdev.conf \
+                       file://xorg.conf.d/99-pitft.conf \
+                     "
 
 do_install_append_rpi () {
 	install -d ${D}/${sysconfdir}/X11/xorg.conf.d/
-	install -m 0644 ${WORKDIR}/xorg.conf.d/* ${D}/${sysconfdir}/X11/xorg.conf.d/
+	install -m 0644 ${WORKDIR}/xorg.conf.d/10-evdev.conf ${D}/${sysconfdir}/X11/xorg.conf.d/
+
+	PITFT="${@bb.utils.contains("MACHINE_FEATURES", "pitft", "1", "0", d)}"
+	if [ "${PITFT}" = "1" ]; then
+		install -m 0644 ${WORKDIR}/xorg.conf.d/99-pitft.conf ${D}/${sysconfdir}/X11/xorg.conf.d/
+	fi
 }
 
 FILES_${PN}_rpi += "${sysconfdir}/X11/xorg.conf ${sysconfdir}/X11/xorg.conf.d/*"

recipes-kernel/linux/linux-raspberrypi.inc

@@ -53,7 +53,11 @@ do_install_prepend() {
 do_deploy_append() {
     # Deploy cmdline.txt
     install -d ${DEPLOYDIR}/bcm2835-bootfiles
-    echo "${CMDLINE}" > ${DEPLOYDIR}/bcm2835-bootfiles/cmdline.txt
+    PITFT="${@bb.utils.contains("MACHINE_FEATURES", "pitft", "1", "0", d)}"
+    if [ ${PITFT} = "1" ]; then
+        PITFT_PARAMS="fbcon=map:10 fbcon=font:VGA8x8"
+    fi
+    echo "${CMDLINE}${PITFT_PARAMS}" > ${DEPLOYDIR}/bcm2835-bootfiles/cmdline.txt
 }
 
 do_rpiboot_mkimage() {