PM_SetBackLight*

C Specification

#include <nitro/spi.h>
u32 PM_SetBackLight( PMLCDTarget target, PMBackLightSwitch sw );

u32 PM_SetBackLightAsync( PMLCDTarget target, PMBackLightSwitch sw, PMCallback callback, void* arg );
  

Arguments

target The screen that is the target of operation.
sw The backlight switch.
callback The callback that is called when the command finishes.
arg The argument that is used when calling the callback.

Return Values

The PM_RESULT_SUCCESS return value indicates that that the execution of the command has succeeded (for synchronous functions) or that the command was successfully sent to the ARM7 processor (for asynchronous functions). The PM_INVALID_COMMAND return value indicates that the argument that was passed is invalid. The PM_RESULT_ERROR return value indicates that an error has occurred with the ARM7 processor.

Description

This function switches the backlight switch of the specified screen.
target is a PMLCDTarget enumerator type that can contain either one of the following values:

PM_LCD_TOP top screen
PM_LCD_BOTTOM bottom screen
PM_LCD_ALL top and bottom screens


sw is a PMBackLightSwitch enumerator type value that specifies one of the following values.

PM_BACKLIGHT_OFF Turns the backlight OFF.
PM_BACKLIGHT_ON Turns the backlight ON.


This function performs the operation that is specified by sw on the screen that is specified by the target argument.

This function uses PXI to send the command that performs the corresponding operation in the ARM7 processor. The ARM7 side that receives that command is executed by operating the PMIC. Therefore, this function may not operate promptly after you call it. A synchronous function that waits for the operation to finish, as well as an asynchronous function that only sends commands to the ARM7, are provided. Use either of the functions depending on your operational requirements. (The asynchronous function has "Async" as part of the function name.))

When an asynchronous function is called, the specified callback is called when processing on the ARM7 side finishes. The callback type PMCallback is defined by:

typedef void ( *PMCallback )( u32 result, void* arg );

This callback is called from within the PXI interrupt handler.

The result argument is the first argument in the callback. The result argument shows the results of the command as either PM_RESULT_SUCCESS or PM_RESULT_ERROR. The second argument in the callback returns the value arg.

Before you use this function, initialize the PM library by using the PM_Init() function. The PM_Init() function has to be called only once. Also, when you call OS_Init(), there is no need to call PM_Init() separately since it is called from within OS_Init().)

Note: If PM_RESULT_ERROR was returned as the return value, it is usually an unrecoverable error. It might be returned when ARM7 is not ready or the variable region was destroyed. If this is returned there may be a problem in the program.

Internal Operation

Operates the PMIC_CTL of the PMIC register.

See Also

PM_Init, PM_GetBackLight

Revision History

07/07/2005 Referred to the return value, PM_RESULT_ERROR.
06/02/2005 Specified the call origin of the callback.
08/04/2004 Initial version.