Sc16is7xx-spi & Rock-CM3

am76 · November 12, 2022, 3:34pm

Hello ,

it is possible to use this chip with rock-CM3 via spi interface ?

I’m trying , but can’t find either a driver or an overlay .

os is deban 11.5,
kernel 4.19.193-56-rockchip-gf62b47f70096:

root@radxa-cm3-io:~# modprobe sc16is7xx
modprobe: FATAL: Module sc16is7xx not found in directory /lib/modules/4.19.193-56-rockchip-gf62b47f70096
root@radxa-cm3-io:~# 
root@radxa-cm3-io:~# find /boot/ -name sc16\*
root@radxa-cm3-io:~#

Some progress (dirty scratch):

driver:
https://wiki.radxa.com/Rock3/dev/Debian
https://wiki.archlinux.org/title/Compile_kernel_module
https://gist.github.com/Josua-SR/3ee497179b75e8e164e508f98b12d810

wget https://releases.linaro.org/components/toolchain/binaries/7.3-2018.05/aarch64-linux-gnu/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
sudo tar xvf gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz -C /opt

git clone -b stable-4.19-rock3 https://github.com/radxa/rockchip-bsp.git
cd rockchip-bsp
git submodule init
git submodule update

git checkout stable-4.19-rock3
git fetch origin
git rebase origin/stable-4.19-rock3
git submodule update

cd kernel
export PATH="/opt/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu/bin:${PATH}"
export ARCH=arm64
export CROSS_COMPILE=aarch64-linux-gnu-

rock=192.168.10.98
ssh -l rock $rock3 cat /proc/config.gz | gzip -dc > .config
make EXTRAVERSION=-58-rockchip menuconfig
#Device Drivers => Character devices => Serial drivers => SC16IS7xx serial support(M) => SC16IS7xx for I2C interface (*), SC16IS7xx for spi interface
#Save, Exit, Exti …

make EXTRAVERSION=-58-rockchip modules_prepare
make EXTRAVERSION=-58-rockchip drivers/tty/serial/sc16is7xx.ko
scp drivers/tty/serial/sc16is7xx.ko root@${rock3}:/lib/modules/4.19.193-58-rockchip-

ssh -l root $rock
depmod
modprobe sc16is7xx
dt-overlay
based on https://github.com/Ysurac/raspberry_kernel_mptcp/blob/master/arch/arm/boot/dts/overlays/sc16is752-spi1-overlay.dts
prepared such a file:
cat sc16is752-spi1-overlay-rock.dts
/dts-v1/;
/plugin/;

/ {
compatible = “radxa,radxa-cm3-io”, “rockchip,rk3566”;
```
 fragment@0 {
         target = <&spi3>;
         frag1: __overlay__ {
                 sc16is752: sc16is752@0 {
                         compatible = "nxp,sc16is752";
                         reg = <0>; /* CE0 */
                         clocks = <&sc16is752_clk>;
                         interrupt-parent = <&gpio3>;
                         interrupts = <3 2>; /* IRQ_TYPE_EDGE_FALLING */
                         #gpio-controller;
                         #gpio-cells = <2>;
                         spi-max-frequency = <4000000>;

                         sc16is752_clk: sc16is752_clk {
                                 compatible = "fixed-clock";
                                 #clock-cells = <0>;
                                 clock-frequency = <14745600>;
                         };
                 };
         };
 };

 __overrides__ {
   int_pin = <&sc16is752>,"interrupts:0";
 };
```
};

dtc -I dts -O dtb sc16is752-spi1-overlay-rock.dts > sc16is752-spi1-overlay-rock.dtb
scp sc16is752-spi1-overlay-rock.dtbo root@${rock3}:/boot/dtbs

ssh -l root $rock3
cd /boot/extlinux
mv extlinux.conf extlinux.conf.orig
cat >extlinux.conf <<EOF
timeout 100
menu title select kernel

label kernel-4.19.193-58-rockchip-gbac1feba87f0
kernel /vmlinuz-4.19.193-58-rockchip-gbac1feba87f0
initrd /initrd.img-4.19.193-58-rockchip-gbac1feba87f0
devicetreedir /dtbs/4.19.193-58-rockchip-gbac1feba87f0
fdtoverlays /dtbs/4.19.193-58-rockchip-gbac1feba87f0/rockchip/overlay/rk3568-fiq-debugger-uart2m0.dtbo /dtbs/4.19.193-58-rockchip-gbac1feba87f0/rockchip/overlay/rk3568-disable-npu.dtbo /dtbs/4.19.193-58-rockchip-gbac1feba87f0/rockchip/overlay/rk3568-spi3-m0-cs0-spidev.dtbo /dtbs/sc16is752-spi1-overlay-rock.dtbo
append root=UUID=00c3a219-6a77-4651-8508-8afe4ed8c9ec earlyprintk console=ttyFIQ0,1500000n8 console=tty1 consoleblank=0 loglevel=7 panic=10 rootwait rw init=/sbin/init rootfstype=ext4 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1 switolb=1 coherent_pool=1m

label kernel-backup
kernel /vmlinuz-4.19.193-58-rockchip-gbac1feba87f0
initrd /initrd.img-4.19.193-58-rockchip-gbac1feba87f0
devicetreedir /dtbs/4.19.193-58-rockchip-gbac1feba87f0
fdtoverlays /dtbs/4.19.193-58-rockchip-gbac1feba87f0/rockchip/overlay/rk3568-fiq-debugger-uart2m0.dtbo /dtbs/4.19.193-58-rockchip-gbac1feba87f0/rockchip/overlay/rk3568-disable-npu.dtbo
append root=UUID=00c3a219-6a77-4651-8508-8afe4ed8c9ec earlyprintk console=ttyFIQ0,1500000n8 console=tty1 consoleblank=0 loglevel=7 panic=10 rootwait rw init=/sbin/init rootfstype=ext4 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1 switolb=1 coherent_pool=1m
EOF
reboot

ssh -l root $rock3
ls -l /dev/ttySC*
crw-rw---- 1 root dialout 238, 0 Nov 11 05:31 /dev/ttySC0
crw-rw---- 1 root dialout 238, 1 Nov 11 05:31 /dev/ttySC1
Connect port by wires and test. looks it works:
root@radxa-cm3-io:~# while date; do date > /dev/ttySC0 ; sleep 1; done
Fri Nov 11 13:52:00 UTC 2022
Fri Nov 11 13:52:01 UTC 2022
Fri Nov 11 13:52:02 UTC 2022
Fri Nov 11 13:52:03 UTC 2022
Fri Nov 11 13:52:04 UTC 2022
Fri Nov 11 13:52:05 UTC 2022
…

root@radxa-cm3-io:~# dd if=/dev/ttySC1 bs=1
Fri Nov 11 13:52:00 UTC 2022

Fri Nov 11 13:52:01 UTC 2022

Fri Nov 11 13:52:02 UTC 2022

Fri Nov 11 13:52:03 UTC 2022

Fri Nov 11 13:52:04 UTC 2022

Fri Nov 11 13:52:05 UTC 2022