add powerd for PocketBook device

frontend/device/generic/powerd.lua

@@ -37,6 +37,17 @@ function BasePowerD:read_int_file(file)
     end
 end
 
+function BasePowerD:read_str_file(file)
+    local fd =  io.open(file, "r")
+    if fd then
+        local str = fd:read("*all")
+        fd:close()
+        return str
+    else
+        return ""
+    end
+end
+
 function BasePowerD:setIntensity(intensity)
     intensity = intensity < self.fl_min and self.fl_min or intensity
     intensity = intensity > self.fl_max and self.fl_max or intensity

frontend/device/pocketbook/device.lua

@@ -74,6 +74,7 @@ local PocketBook840 = PocketBook:new{
 
 function PocketBook840:init()
     self.screen = require("ffi/framebuffer_mxcfb"):new{device = self, debug = DEBUG}
+    self.powerd = require("device/pocketbook/powerd"):new{device = self}
     self.input = require("device/input"):new{
         device = self,
         event_map = {

frontend/device/pocketbook/powerd.lua

@@ -0,0 +1,31 @@
+local BasePowerD = require("device/generic/powerd")
+local ffi = require("ffi")
+local inkview = ffi.load("inkview")
+
+ffi.cdef[[
+int IsCharging();
+]]
+
+local PocketBookPowerD = BasePowerD:new{
+    battCapacity = nil,
+    is_charging = nil,
+    batt_capacity_file = "/sys/devices/platform/sun5i-i2c.0/i2c-0/0-0034/axp20-supplyer.28/power_supply/battery/capacity",
+    is_charging_file = "/sys/devices/platform/sun5i-i2c.0/i2c-0/0-0034/axp20-supplyer.28/power_supply/battery/status",
+}
+
+function PocketBookPowerD:init()
+end
+
+function PocketBookPowerD:getCapacityHW()
+    self.battCapacity = self:read_int_file(self.batt_capacity_file)
+    return self.battCapacity
+end
+
+function PocketBookPowerD:isChargingHW()
+    self.is_charging = self:read_str_file(self.is_charging_file)
+    return self.is_charging == "Charging"
+    -- or we can query using SDK method `IsCharging`
+    --return inkview.IsCharging() == 1
+end
+
+return PocketBookPowerD