rpi-config: I2C support

With newer kernels (>=3.18) that supports device-trees I2C
should be enabled with device-trees.

This is now support by adding:
ENABLE_I2C = "1"
in local.conf

This will enable the dtparams:
i2c1
i2c_arm

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

2 files changed, 13 insertions, 0 deletions

diff --git a/README b/README
index 5798e61..3e879dd 100644
--- a/README
+++ b/README
@@ -27,6 +27,7 @@ Contents:
     3.J. Image with Initramfs
     3.K. Device tree support
     3.L. Enable SPI bus
+    3.M. Enable I2C
 4. Extra apps
     4.A. omxplayer
 5. Board Configuration
@@ -207,6 +208,12 @@ NOTE: KERNEL_DEVICETREE is default enabled for kernel >= 3.18 and always disable
 When using device tree kernels, set this variable to enable the SPI bus
 ENABLE_SPI_BUS = "1"
 
+3.M. Enable I2C
+===============
+When using device tree kernels, set this variable to enable I2C
+ENABLE_I2C = "1"
+
+
 4. Extra apps
 =============
 
diff --git a/recipes-bsp/bootfiles/rpi-config_git.bb b/recipes-bsp/bootfiles/rpi-config_git.bb
index 4cdffca..138cb37 100644
--- a/recipes-bsp/bootfiles/rpi-config_git.bb
+++ b/recipes-bsp/bootfiles/rpi-config_git.bb
@@ -75,6 +75,12 @@ do_deploy() {
         echo "# Enable SPI bus" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
         echo "dtparam=spi=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
     fi
+
+    if [ -n "${ENABLE_I2C}" ]; then
+        echo "# Enable I2C" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+        echo "dtparam=i2c1=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+        echo "dtparam=i2c_arm=on" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+    fi
 }
 
 addtask deploy before do_package after do_install