Surface-Fakedev

Description:

This mimics battery devices in /etc/fakedev (workaround until a battery module is available). Please read carefully all the way to the end. I strongly advise to test the power-status.py script before installation. Just run install.sh w/o root. It will fail but however create the "power-status.py" script if fed with the correct arguments (read below). The script is tested running on SurfacPro 5 series. It is tested on Ubuntu > 18 and Manjaro > 17 on kernels down to 4.9 series and latest 4.19rc. I used always Python3.7 but it should also work with 3.5

Prerequirements:

python3 (should be installed already), python3-crcmod, python3-serial

sudo apt get install python3-crcmod python3-serial

Test before installation for the serial port.

$ dmesg | grep ttyS
[    5.426845] dw-apb-uart.2: ttyS0 at MMIO 0xa1336000 (irq = 20, base_baud = 3000000) is a 16550A

$ sudo cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:16550A mmio:0xA1336000 irq:20 tx:510 rx:2130
1: uart:unknown port:000002F8 irq:3
2: uart:unknown port:000003E8 irq:4
3: uart:unknown port:000002E8 irq:3

If there are no results you cannot use this package unless you get an uart-driver attached to it. Your results do not have to match the examples above. The second ouput can be used to check if there is communication (tx and rx) happening on the device.

Installation:

Download the zip file or clone to your home directory. Make "install.sh" excecutable. "sh ./install.sh" won't work (too much bash stuff in there).

chmod 755 install.sh

Run it as root. Examples:

• Note: run w/o root just to create the power-status.py script first, no files will be copied

sudo ./install.sh               # default. reads from /dev/ttyS4 at 3000000 baud
sudo ./install.sh ttyS0         # reads from /dev/ttyS0 at 3000000 baud
sudo ./install.sh ttyS4 1800000 # reads from /dev/ttyS4 at 1800000 baud

If you need to change the baud rate you MUST give the ttyS[N] as first argument. Use the values you found with the dmesg command. You will then be asked for the Number of batteries. Choose 1 or 2 depending on your hardware. If ran w/o root, ignore the following messages and just hit enter.

Tests before installing with root:

sudo ./power-status.py adp1.uevent # AC adapter. If this fails the next commands may still work.
sudo ./power-status.py bat1.uevent # battery one
sudo ./power-status.py bat2.uevent # battery two is present. Will fail otherwise

After installation the following files will be created.

• a cronjob in "/etc/cron.d/power-status running every minute
• copies the file "pwr-cron.sh" to "/sbin" executed by cron
• copies the file "power-status.py" to "/usr/bin/" which will be executed by "pwr-cron.sh"
• The python script will create a file in "/tmp" named "surface-ec-counters.json" for stats.

The "pwr-cron.sh" script will create the directories "/etc/fakedev/power_supply/BAT1" BAT2 (if 2 batteries) and ADP1 (the AC power supply). This mimics "/sys/class/power_supply/" which cannot be created from user space. Inside the fakedev directories the "power-status.py" python3 script will create the uevent files, where you can point your battery monitor to (possible with i3status). Other DE's will need a workaround via i.e. gnome shell. I cannot provide this. The entry in your i3status.conf is as follows

order += "battery all"

battery all { 
        # format = "%status %percentage %remaining %emptytime"
        # format = " %percentage"
        format = " %status %percentage"
        format_down = "No battery"
        last_full_capacity = true
        integer_battery_capacity = true
        # status_chr = ""
        status_chr = "⚡"
        # status_bat = "bat"
        # status_bat = "☉"
        status_bat = "" 
        # status_unk = "?"
        status_unk = ""
        # status_full = ""
        status_full = "☻" 
        low_threshold = 15
        path = "/etc/fakedev/power_supply/BAT%d/uevent"  <-------------
}

Add the line marked with "<----" to your i3status.conf file which originally resides in /etc in the Manjaro i3 edition. A solution for gnome like DEs can be found here: jakeday/linux-surface#28 (comment) At this time it has a little glitch and won't work with only one battery. Work around this by creating a link:

sudo ln -s /etc/fakedev/power_supply/BAT1/uevent /etc/fakedev/power_supply/BAT2/uevent

It will then show 2 batteries.

Notes:

The python script is originally from @qzed's proof of concept and can be found here: https://gist.github.com/qzed/01a93568efb863f1b7887f0f375c03fc I only modified it to fit it's output to the uevent file format. I don't no much about python so please bare with me.

Of course, there is no guarantee for anything. Use on your own risk.