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[Q3]We can only use Iclass(GUID) to realize PWM, but using DeviceName will not do, why?--[i.MX53,WEC7]

Question asked by john Phy on Oct 30, 2013
Latest reply on Nov 6, 2013 by john Phy

[Q3]We can only use Iclass(GUID) to realize PWM, but using DeviceName will not do, why?--[i.MX53,WEC7]

 

   We want to disable the GPIO keypad when the screen is off, and the GPIO keypad should go to D4 mode. But we can only use the Iclass(GUID) to realize this function.

   The registery set below will not work(Set GPIO Keypad Iclass as Generic power-manageable devices and set GKP1 go to D4 mode when screenoff,but the GPIO Keypad Driver can not get power control command):

;------------------------------------------------------------------------------

; GPIO Keypad Driver

;

IF BSP_GPIO_KEYPAD

[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\GPIOKEYPAD]

   "Prefix"="GKP"

   "Dll"="gpiokeypad.dll"

   "Index"=dword:1

   "Order"=dword:12

;---------------------------------------------------------------------------------------

   "IClass"="{A32942B7-920C-486b-B0E6-92A702A99B35}"   ;"Generic power-manageable devices"

;---------------------------------------------------------------------------------------

 

ENDIF ;BSP_GPIO_KEYPAD

;------------------------------------------------------------------------------

;

; Normal operation, but with UI disabled

;

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff]

    "Default"=dword:0       ; D0

    "Flags"=dword:100000    ; POWER_STATE_IDLE

;------------------------------------------------------------------

    "GKP1:"=dword:4         ; D4 (This set will not work, why !)

;------------------------------------------------------------------

 

; @CESYSGEN IF CE_MODULES_BACKLIGHT

; The default behaviour for backlight drivers is to go to D4 in ScreenOff.

; OEMS who support D2/D3 can override this in the platform

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff\{0007AE3D-413C-4e7e-8786-E2A696E73A6E}]

    "Default"=dword:4           ; D4    ; backlight off

; @CESYSGEN ELSE

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff]

    "BKL1:"=dword:4    ; legacy support

; @CESYSGEN ENDIF CE_MODULES_BACKLIGHT

 

 

 

  But the registery set below will work well(Set GPIO Keypad Iclass as "Power-manageable backlight", when screenoff the GPIO Keypad Driver can get power control command and go to D4 mode):

 

;------------------------------------------------------------------------------

; GPIO Keypad Driver

;

IF BSP_GPIO_KEYPAD

[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\GPIOKEYPAD]

   "Prefix"="GKP"

   "Dll"="gpiokeypad.dll"

   "Index"=dword:1

   "Order"=dword:12

;---------------------------------------------------------------------------------------

   "IClass"="{0007AE3D-413C-4e7e-8786-E2A696E73A6E}"    ;"Power-manageable backlight"

;--------------------------------------------------------------------------------------

ENDIF ;BSP_GPIO_KEYPAD

;------------------------------------------------------------------------------

;

; Normal operation, but with UI disabled

;

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff]

    "Default"=dword:0       ; D0

    "Flags"=dword:100000    ; POWER_STATE_IDLE 

 

 

; @CESYSGEN IF CE_MODULES_BACKLIGHT

; The default behaviour for backlight drivers is to go to D4 in ScreenOff.

; OEMS who support D2/D3 can override this in the platform

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff\{0007AE3D-413C-4e7e-8786-E2A696E73A6E}]

    "Default"=dword:4           ; D4    ; backlight off

; @CESYSGEN ELSE

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State\ScreenOff]

    "BKL1:"=dword:4    ; legacy support

; @CESYSGEN ENDIF CE_MODULES_BACKLIGHT

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