I am trying to configure an SC16IS752 device but my unfamiliarity with linux is getting in the way.
In the /boot/config-4.19.94-ti-r73 file I see SC16IS7XX is not set
I also cannot find any related driver using find /lib/modules | grep sc16
How do I enable this device?
Hi @Ndziura feel free to re-enable that config:
CONFIG_SERIAL_SC16IS7XX_CORE
CONFIG_SERIAL_SC16IS7XX
CONFIG_SERIAL_SC16IS7XX_I2C
CONFIG_SERIAL_SC16IS7XX_SPI
I had to disable it for us, as the breaks SERIAL_DEV_CTRL_TTYPORT, which breaks Bluetooth on wl18xx… which breaks the Black Wireless, Green Wireless, Gateway etc…
Regards,
@RobertCNelson Im not familiar with linux, so I dont know how to re enable the config. Do I just add those lines to boot/config-4.19.94-ti-r73?
Hi @Ndziura you get to rebuild the kernel:
Do this on an x86 desktop running Debian or Ubuntu…
git clone -b ti-linux-4.19.y https://github.com/RobertCNelson/ti-linux-kernel-dev
cd ti-linux-kernel-dev/
Then edit patches/defconfig to match these changes:
diff --git a/patches/defconfig b/patches/defconfig
index 7d51d5f5..1076dfd2 100644
--- a/patches/defconfig
+++ b/patches/defconfig
@@ -2818,7 +2818,10 @@ CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_OMAP is not set
# CONFIG_SERIAL_SCCNXP is not set
-# CONFIG_SERIAL_SC16IS7XX is not set
+CONFIG_SERIAL_SC16IS7XX_CORE=m
+CONFIG_SERIAL_SC16IS7XX=m
+CONFIG_SERIAL_SC16IS7XX_I2C=y
+CONFIG_SERIAL_SC16IS7XX_SPI=y
# CONFIG_SERIAL_BCM63XX is not set
# CONFIG_SERIAL_ALTERA_JTAGUART is not set
# CONFIG_SERIAL_ALTERA_UART is not set
@@ -2830,7 +2833,7 @@ CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_ST_ASC is not set
# CONFIG_SERIAL_PRU_SUART is not set
CONFIG_SERIAL_DEV_BUS=y
-CONFIG_SERIAL_DEV_CTRL_TTYPORT=y
+# CONFIG_SERIAL_DEV_CTRL_TTYPORT is not set
CONFIG_TTY_PRINTK=m
CONFIG_HVC_DRIVER=y
# CONFIG_HVC_DCC is not set
Then run ./build_deb.sh
Wait till build finishes, then copy ./deploy/linux-image*.deb to beagle and install…
sudo dpkg -i linux-image*.deb
Regards,
The CONFIG_SERIAL_SC16IS7XX lines in the config are now set and I see kernel/drivers/tty/serialsc16is7xx.ko.xz, but no SC16IS .dtbo files in /lib/firmware and no ttySC* in /dev.
Should they be there or should I be looking for something else?
Did you write an SC16IS*.dtbo overlay? or did you customize the device tree for a SC16IS node? Then no, unless you write something for the SC16IS and load it, it won’t show up… Which pins are you thinking of using?
Regards,
I need to use the SPI1 pins, with chip select 0. So I need to write and compile a device tree overlay for those pins?
Thanks, Nick
Here’s one example, change the spi1 section:
Regards,
I have modified the file, however when I try to compile it I get the error
FATAL ERROR: Unable to parse input tree
on the line:
#include <dt-bindings/board/am335x-bbw-bbb-base.h
According to this tutorial: Using Device Tree Overlays, example on BeagleBone boards
I need to remake the linux kernel, however the command
make dtbs
returns
no rule to make target dtbs
Is the tutorial accurate in what I need to do? If so what could be the cause of the error?
you did it this way right?
git clone https://github.com/beagleboard/bb.org-overlays.git
cd ./bb.org-overlays/
#make changes
make
sudo make install
Regards,
That compilation method works but I assume the changes I made to the .dts file aren’t right.
The changes I made from the LTC2947 file were changing the labels as well as changing the max frequency to that specified in the datasheet for the SC16IS752.
BB-SPI1-SC16IS752-00A0.dts (2.2 KB)
You’ll need to define the clock speed or clock input: a long with the interrupt:
Required properties:
- compatible: Should be one of the following:
- “nxp,sc16is740” for NXP SC16IS740,
- “nxp,sc16is741” for NXP SC16IS741,
- “nxp,sc16is750” for NXP SC16IS750,
- “nxp,sc16is752” for NXP SC16IS752,
- “nxp,sc16is760” for NXP SC16IS760,
- “nxp,sc16is762” for NXP SC16IS762.
- reg: SPI chip select number.
- interrupts: Specifies the interrupt source of the parent interrupt
controller. The format of the interrupt specifier depends on the
parent interrupt controller.- clocks: phandle to the IC source clock.
Example:
sc16is750: sc16is750@0 {
compatible = "nxp,sc16is750";
reg = <0>;
clocks = <&clk20m>;
interrupt-parent = <&gpio3>;
interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
gpio-controller;
#gpio-cells = <2>;
};
Here’s an in-kernel example on how you could define the clock for this:
Regards,