如下表所示，coolpi 4b的40PIN连接器可以引出4组I2C总线出来，其中I2C1 I2C3 I2C5是独立I2C接口，机器内部没有和其它设备复用，I2C6板子内部有接RTC时钟芯片HYM8563，地址为51H，所以外设使用I2C6端口的时候注意地址不要冲突。

I2C位置

DTS配置

设备驱动的配置方式参考I2C6节点，注意不使用I2C功能确保节点的status为disabled，否则可能会导致其它功能异常。

&i2c1 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&i2c1m2_xfer>;
};

&i2c3 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&i2c3m2_xfer>;
};

&i2c5 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&i2c5m2_xfer>;
};

&i2c6 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&i2c6m3_xfer>;

	hym8563: hym8563@51 {
		compatible = "haoyu,hym8563";
		reg = <0x51>;
		#clock-cells = <0>;
		clock-frequency = <32768>;
		clock-output-names = "hym8563";
		pinctrl-names = "default";
		pinctrl-0 = <&hym8563_int>;
		interrupt-parent = <&gpio0>;
		interrupts = <RK_PB0 IRQ_TYPE_LEVEL_LOW>;
		status = "okay";
	};

};

测试工具及方法

git clone git://git.kernel.org/pub/scm/utils/i2c-tools/i2c-tools.git
cd i2c-tools
make -j8
sudo make install
root@ubuntu:/# i2cdetect -y 6
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --
I2C6节点上可以扫描到地址为51H的设备，即HYM8563。工具也支持其他读写操作。可以自行研究。

@mainbord
The efficiency of the Panthor driver is currently lower, and we look forward to future updates.

如下表所示，40pin连接器包含7个可用于输出PWM信号的GPIO，其中PIN5 PIN12共用PWM3，PIN38 PIN40共用PWM15，这两个PWM信号同一时刻只能从一个GPIO输出，不能2个GPIO同时输出，所以40PIN连接器一共有5个独立的PWM口可以同时工作 ：

DTS配置

PWM2口配置如下，其它接口类似，首先配置PWM接口对应的pinctrl,比如PWM2为PWM2_M1,然后使能节点即可。

&pwm2 {
	pinctrl-0 = <&pwm2m1_pins>;
	status = "okay";
};

操作PWM

• 使用 echo 命令将要操作的 PWM 编号 export，注意操作需要root权限。

root@coolpi-4b:/# echo 0 >/sys/class/pwm/pwmchip2/export  
/*export 之后就会生成/sys/class/pwm/pwmchip2/pwm0目录*/
root@coolpi-4b:/sys/class/pwm/pwmchip2/pwm0# ls
capture  duty_cycle  enable  output_type  period  polarity  power  uevent

• 使用 echo 命令设置 PWM 的周期：

echo 1000000 > /sys/class/pwm/pwmchip2/pwm0/period
/*设置PWM一个周期的时间，单位为ns，即一个周期为1KHZ。*/

• 使用 echo 命令设置 PWM 的占空比：

echo 500000 > /sys/class/pwm/pwmchip2/pwm0/duty_cycle
/*设置PWM一个周期中“ON”的时间，单位为ns，即占空比=duty_cycle/period=50%。*/

• 使用 echo 命令使能 PWM

echo 1 > /sys/class/pwm/pwmchip2/pwm0/enable 

@plumlis
Refer to the following link to compile and install.
https://github.com/coolpi-george/panfork.git

@Eel
The 4K panel can only light up normally on the motherboard, but in fact, 4K will bring an increase in power consumption, which feels a bit unprofitable. I have been working hard on power consumption recently, hoping to make significant progress.

@AugustRobot_Zou 可以的。POE供电的场景就是通过排针的5V输入的。

The CM5 laptop is currently crowdfunding on the CrowdSupply platform, with a new product name called GenBook-RK3588. The following improvements will be made to the current laptop product:

• The memory has been fully upgraded to LPDDR5X for better energy efficiency.
• The capacity of the battery has increased, but the specific capacity of the structure is still in the evaluation stage.
• The module language supports TPM (Trusted Platform Module).
• The speaker effect in the audio section continues to improve and reduce background noise.
• Optimize the overall power consumption and expect longer usage time.
• The software supports the mainline kernel and is expected to be submitted in mid July.
• Improvement of various Linux distributions.
  If you have any better suggestions, you can share them with us. Thank you for your support.

@AugustRobot_Zou 按照5V 3A的标准来配置。一般散热按照12W评估。正常工作也就5W左右。

@Momo-0
The 3.5mm headphone jack has output and MIC functions.

The partitioning situation of the Coolpi image file is as follow

• The first partition has a size of 512M and a partition format of fat32, used to store boot- files. The default boot mode is extLinux.
• The second partition is the file system, with different sizes depending on the distribution. The partition format is ext4. The label of the partition is writable, which needs to be consistent with the configuration information under extLinux.
  
• The file of the boot partition is shown in the following figure, which you can access through/ The build kernel. sh command compiles the coolpi kernel, and then the files in the out directory need to be copied to the boot partition.
  
• The content is as follows extlinux.conf，Pay special attention to the loading method of the file system, which is searched through label (writable). Of course, it can also be modified to UUID or other types.

default Linux coolpi

label Linux coolpi
	kernel /Image
	initrd /initrd.img
	fdt    /rk3588-cpcm5-notebook-v20.dtb
	append root=LABEL=writable rw rootfstype=ext4 console=ttyS0,115200n81 quiet splash plymouth.ignore-serial-consoles vt.global_cursor_default=1 irqchip.gicv3_pseudo_nmi=0 net.ifnames=0

Start creating a mirror image

• Create an 8GB img file using the following command. Then partition and format.

LOOP_NUMBER=$(losetup -f)
dd if=/dev/zero of=./coolpi.img bs=1M count=8192    
printf 'n\np\n1\n32768\n1081343\nn\np\n2\n1081344\n16777215\nw\n' | fdisk ./coolpi.img   
partx -a -v ./coolpi.img      
mkfs.vfat $LOOP_NUMBER"p1"      
echo 'yes\n' | mkfs.ext4 $LOOP_NUMBER"p2"   
e2label  $LOOP_NUMBER"p2" writable

• Copy files to boot partition，kernel-dir is the file directory corresponding to the Coolpi kernel.

mkdir ./mnt
mount $LOOP_NUMBER"p1" ./mnt
cp  kernel-dir/out/* ./mnt -r
umount  ./mnt

• Create a file system, Add rc.local file to automatically expand partitions and configure some system node permissions.

wget https://mirrors.aliyun.com/archlinuxarm/os/ArchLinuxARM-aarch64-latest.tar.gz
mkdir ./archlinux
tar -zxvf ArchLinuxARM-aarch64-latest.tar.gz -C ./archlinux/
mount $LOOP_NUMBER"p2" ./mnt
cp -rf ./archlinux/* ./mnt/ 
tar -zxvf  kernel-dir/out/modules.tar.gz -C ./mnt/lib/
cp ./rc.local  ./mnt/etc/
umount ./mnt
e2fsck -p -f $LOOP_NUMBER"p2"
resize2fs -M $LOOP_NUMBER"p2"
losetup -D $LOOP_NUMBER

@rtmtree
The 8MB is SPI-NOR memory, which stores bootloader and UBOOT internally. If the disk is formatted, it will not start properly. Don't worry, just update the image again. Provide an update method later.

Refer to the following document：
https://github.com/coolpi-george/Docs/blob/main/cm5-notebook/update-loader.md