From 7512f5f2a11f36c22f0c8057e875a84cfc8fc1ee Mon Sep 17 00:00:00 2001
From: 2Shirt <2xShirt@gmail.com>
Date: Sat, 8 Oct 2022 20:28:33 -0700
Subject: [PATCH] Add set_lp8550_slope.py

Addresses issue #17
---
 scripts/set_lp8550_slope.py                   | 103 ++++++++++++++++++
 setup/linux/packages/aur                      |   1 +
 .../profile_base/airootfs/etc/skel/.aliases   |   1 +
 3 files changed, 105 insertions(+)
 create mode 100755 scripts/set_lp8550_slope.py

diff --git a/scripts/set_lp8550_slope.py b/scripts/set_lp8550_slope.py
new file mode 100755
index 00000000..f074061f
--- /dev/null
+++ b/scripts/set_lp8550_slope.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+###
+# Dependencies: Linux, python3, python3-smbus
+# Usage: `sudo ./set_lp8550_slope.py`
+#
+# Default slope is 0b101=200ms, can be adjusted below
+# Tested with Ubuntu 20.04 on A1466 2013
+# All original EEPROM registers value:
+# - A0: 0b01111111
+# - A1: 0b10110101
+# - A2: 0b10111111
+# - A3: 0b01111011
+# - A4: 0b00101000
+# - A5: 0b11001111
+# - A6: 0b01100100
+# - A7: 0b00101101
+###
+
+import time
+
+import smbus2
+
+config = {
+  'smbus_address': 0, # SMBus address, can use `i2cdetect -l` to find it
+  'device_address': 0x2C, # LP8550 7 bits address
+  'slope': (1, 0, 1) # The new slope to set, MSB first, see lp8550 datasheet 8.6.2.3 SLOPE
+}
+
+lp8550_regs = {
+  'EEPROMControl': 0x72,
+  'EEPROMAddress1': 0xA1 # default value for this register is 0b10110101 on original 820-3437
+}
+
+def bitstolist(val, regsize=8):
+  return [(val >> i) & 0b1 for i in range(0, regsize)]
+
+def listtobits(l, regsize=8):
+  val = 0
+  for i in range(0, regsize):
+    val += l[i] << i
+  return val
+
+def read_reg(bus, dev_address, reg_name):
+  return bitstolist(bus.read_byte_data(dev_address, lp8550_regs[reg_name]))
+
+def write_reg(bus, dev_address, reg_name, reg):
+  print(f'Writing { listtobits(reg)} to {dev_address}, {lp8550_regs[reg_name]}')
+  bus.write_byte_data(dev_address, lp8550_regs[reg_name], listtobits(reg))
+
+def get_slope(bus, dev_address):
+  return read_reg(bus, dev_address, 'EEPROMAddress1')[0:3][::-1]
+
+def set_slope(bus, dev_address, slope):
+  print('Original slope: ', get_slope(bus, dev_address))
+
+  EEPROMAddress1 = read_reg(bus, dev_address, 'EEPROMAddress1')
+  EEPROMAddress1[0:3] = slope[::-1]
+
+  write_reg(bus, dev_address, 'EEPROMAddress1', EEPROMAddress1)
+
+  print('New slope: ', get_slope(bus, dev_address))
+
+def write_nvm(bus, dev_address):
+  print('Writing to non-volatile memory')
+  EEPROMControl = [0]*8
+  EEPROMControl[2] = 1 # EE_INIT=1
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+  EEPROMControl[1] = 1 # EE_PROG=1
+  EEPROMControl[2] = 0 # EE_INIT=0
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+  time.sleep(0.2) # wait 200ms
+
+  EEPROMControl[1] = 0 # EE_PROG=0
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+def load_nvm(bus, dev_address):
+  print('Loading from non-volatile memory')
+  EEPROMControl = [0]*8
+  EEPROMControl[2] = 1 # EE_INIT=1
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+  EEPROMControl[0] = 1 # EE_READ=1
+  EEPROMControl[2] = 0 # EE_INIT=0
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+  time.sleep(0.2) # wait 200ms
+
+  EEPROMControl[0] = 0 # EE_READ=0
+  write_reg(bus, dev_address, 'EEPROMControl', EEPROMControl)
+
+def main():
+  bus = smbus2.SMBus(config['smbus_address'])
+
+  set_slope(bus, config['device_address'], config['slope'])
+  write_nvm(bus, config['device_address'])
+  load_nvm(bus, config['device_address'])
+
+  print('Slope in non-volatile memory: ', get_slope(bus,config['device_address']))
+
+if __name__ == "__main__":
+  main()
diff --git a/setup/linux/packages/aur b/setup/linux/packages/aur
index cc80e928..ef8ef5d6 100644
--- a/setup/linux/packages/aur
+++ b/setup/linux/packages/aur
@@ -9,6 +9,7 @@ mprime
 openbox-patched
 pipes.sh
 python-mariadb-connector
+python-smbus2
 smartmontools-svn
 testdisk-wip
 ttf-font-awesome-4
diff --git a/setup/linux/profile_base/airootfs/etc/skel/.aliases b/setup/linux/profile_base/airootfs/etc/skel/.aliases
index 7e118fff..a0d7114b 100644
--- a/setup/linux/profile_base/airootfs/etc/skel/.aliases
+++ b/setup/linux/profile_base/airootfs/etc/skel/.aliases
@@ -31,6 +31,7 @@ alias rmdirs='find -depth -mindepth 1 -type d -exec rmdir "{}" --ignore-fail-on-
 alias rs='rsync -avhPS --stats --exclude-from="$HOME/.rsync_exclusions"'
 alias rsz='rsync -avhzPS --stats --exclude-from="$HOME/.rsync_exclusions"'
 alias sdu='sudo du -sch --apparent-size'
+alias set_lp8550_slope='sudo set_lp8550_slope.py'
 alias srmdirs='sudo find -depth -mindepth 1 -type d -exec rmdir "{}" --ignore-fail-on-non-empty \;'
 alias srs='sudo rsync -avhPS --stats --exclude-from="$HOME/.rsync_exclusions"'
 alias srsz='sudo rsync -avhzPS --stats --exclude-from="$HOME/.rsync_exclusions"'