From 3d01bee02309933f696c5d704343357e155c72c6 Mon Sep 17 00:00:00 2001
From: Martin Kepplinger <martin.kepplinger@puri.sm>
Date: Sun, 29 Mar 2020 13:06:49 +0200
Subject: [PATCH] power_key.py: make compatible with all our kernels

devfreq is being handled differently on our kernels. This implements
the various logics, with 5.7+ not needing the script anymore, for devfreq,
when the powersave governor is set by udev.
---
 usr/bin/power_key.py | 57 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 45 insertions(+), 12 deletions(-)

diff --git a/usr/bin/power_key.py b/usr/bin/power_key.py
index 25c65bd..263874e 100755
--- a/usr/bin/power_key.py
+++ b/usr/bin/power_key.py
@@ -8,6 +8,26 @@ import sys
 import evdev
 
 
+# 5.X
+kernel_version = 3
+
+
+def get_kernel_version():
+    with open("/proc/version") as f:
+        global kernel_version
+        if 'version 5.6.' in f.read():
+            kernel_version = 6
+        elif 'version 5.7.' in f.read():
+            kernel_version = 7
+        else:
+            kernel_version = 8
+
+
+# devfreq logic:
+# for 5.6+ new sysfs paths
+# for 5.7+ check for powersave governor only (interconnect solution)
+
+
 def check_screen():
     with open("/sys/class/leds/lm36922:white:backlight_cluster/brightness") as ledf:
         state = ledf.read()
@@ -28,20 +48,25 @@ def find_dram_devfreq():
     return dram
 
 
-set_freq = os.path.join(find_dram_devfreq(), 'userspace/set_freq')
-
-
 def set_dram_freq(freq):
-    with open(set_freq, "w+") as f:
+    with open(os.path.join(find_dram_devfreq(), 'userspace/set_freq'), "w+") as f:
         f.write(freq + "\n")
 
 
-def get_low_freq():
-    with open("/proc/version") as f:
-        return ["25000000", "100000000"]['version 5.3.' in f.read()]
+# different on the devkit and the phone
+def get_low_freq_dram():
+    if kernel_version == 3:
+        return "100000000"
+    else:
+        with open(os.path.join(find_dram_devfreq(), 'min_freq')) as f:
+            freq = f.read()
+            return freq
 
 
 def main(args):
+    get_kernel_version()
+    print("for kernel version 5.%d" % (kernel_version))
+
     powerkeyname = '30370000.snvs:snvs-powerkey'
     hi_speed = "800000000"
 
@@ -50,9 +75,14 @@ def main(args):
     dev = InputDevice(foundpath)
 
     with open(os.path.join(find_dram_devfreq(), 'governor'), "w+") as f:
-        f.write("userspace\n")
+        if kernel_version < 7:
+            f.write("userspace\n")
+        else:
+            # should be set by udev already
+            f.write("powersave\n")
 
-    set_dram_freq(hi_speed)
+    if kernel_version < 7:
+        set_dram_freq(hi_speed)
 
     power_wait_time = 1.5
 
@@ -60,7 +90,8 @@ def main(args):
         blank = False
     else:
         blank = True
-        set_dram_freq(get_low_freq())
+        if kernel_version < 7:
+            set_dram_freq(get_low_freq_dram())
 
     # wait for the key release event so that we can differentiate
     # between long and short press
@@ -78,7 +109,8 @@ def main(args):
                         if event.code == ecodes.KEY_POWER and blank:
                             print("screen wakeup")
                             blank = False
-                            set_dram_freq(hi_speed)
+                            if kernel_version < 7:
+                                set_dram_freq(hi_speed)
                         else:
                             state[event.code] = event.timestamp(), event
                             print("Key: %s %d %d pressed" % (ecodes.KEY[event.code], event.code, ecodes.KEY_POWER))
@@ -90,7 +122,8 @@ def main(args):
                         if event.code == ecodes.KEY_POWER and delta < power_wait_time:
                             # short power key press blanks the screen so change the DDR freq
                             blank = True
-                            set_dram_freq(get_low_freq())
+                            if kernel_version < 7:
+                                set_dram_freq(get_low_freq_dram())
                             # os.system("systemctl suspend -q")
 
                         del state[event.code]
-- 
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