How to implement PWM control with AM3517?

Kevin Chow

Other Parts Discussed in Thread: AM3517

Hi,

I have a custom board with am3517, and I add pwm control on hardware, so I want to control the back-light, How to implement it by pwm in kernel and u-boot?

Thanks,

Kevin

over 14 years ago

0 Vishveshwar Bhat over 14 years ago

TI__Genius 10210 points

If you are using PWM capable GPIO then you will need to first enable the PWM in the kernel config.

Do browse through the kernel sources to see how different boards implement PWM-based backlight/GPIO controls.

0 Kevin Chow over 14 years ago

Expert 1625 points

According to my 7" LCD specification, I should set pwm to low to enable the LCD become high brightness.

In kernel 2.6.32, I changed some codes, and now my LCD can display.

@kernel/arch/arm/mach-omap2/board-am3517evm.c

@line 346

-------------------------from------------------------

gpio_direction_output(LCD_PANEL_PWM, 1);

--------------------------to-------------------------

gpio_direction_output(LCD_PANEL_PWM, 0);

Regards,

0 ted juan over 14 years ago in reply to Vishveshwar Bhat

Prodigy 225 points

Is there a any PWM define in the kernel config for AM3517?

Processors

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How to implement PWM control with AM3517?