rpi-config: Add CAN_OSCILLATOR variable to set mcp2515 crystal frequency

Current configuration (16MHz) is made for the PiCAN2 board that uses 16MHz crystal. This setting allows for use of Waveshare RS485 CAN HAT that has 8MHz crystal soldered (although according to Waveshare there is also a 12MHz crystal version of the board).

Signed-off-by: Jakub Luzny <jakub@luzny.cz>

1 files changed, 5 insertions, 3 deletions

diff --git a/recipes-bsp/bootfiles/rpi-config_git.bb b/recipes-bsp/bootfiles/rpi-config_git.bb
index afdbce6..be84aa6 100644
--- a/recipes-bsp/bootfiles/rpi-config_git.bb
+++ b/recipes-bsp/bootfiles/rpi-config_git.bb
@@ -28,6 +28,8 @@ VC4DTBO ?= "vc4-kms-v3d"
 GPIO_IR ?= "18"
 GPIO_IR_TX ?= "17"
 
+CAN_OSCILLATOR ?= "16000000"
+
 inherit deploy nopackages
 
 do_deploy() {
@@ -201,12 +203,12 @@ do_deploy() {
     # ENABLE DUAL CAN
     if [ "${ENABLE_DUAL_CAN}" = "1" ]; then
         echo "# Enable DUAL CAN" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
-        echo "dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
-        echo "dtoverlay=mcp2515-can1,oscillator=16000000,interrupt=24" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+        echo "dtoverlay=mcp2515-can0,oscillator=${CAN_OSCILLATOR},interrupt=25" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+        echo "dtoverlay=mcp2515-can1,oscillator=${CAN_OSCILLATOR},interrupt=24" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
     # ENABLE CAN
     elif [ "${ENABLE_CAN}" = "1" ]; then
         echo "# Enable CAN" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
-        echo "dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
+        echo "dtoverlay=mcp2515-can0,oscillator=${CAN_OSCILLATOR},interrupt=25" >>${DEPLOYDIR}/bcm2835-bootfiles/config.txt
     fi
 
     # Append extra config if the user has provided any