Hi All,
We are using our custom board with DM385 and using Pad Y11( GPMC_BE[1]/GPMC_A[24]/EDMA_EVT1/TIM7_IO/GP1[30] ) as TIM7_IO for camera flash light as PWM. We need to make flash light off when we boot. So for the same we made change in u-boot to configure this pad as GP1[30] and set output to low as below.
add=0x4804C13C; //GPIO_DATAOUT Register
val = __raw_readl(add);
val &=~(1<<30); //GP1[30] -Set Output Low
__raw_writel(val, add);
//GPIO1[] group
add=0x4804C134; //GPIO_OE Output Enable Register
val = __raw_readl(add);
val &=~(1<<30); //GP1[30]
__raw_writel(val, add);
__raw_writel((1<<30), 0x4804c190); //output low
With this changes Flash light goes off at u-boot .
But before starting u-boot, for fraction of second Flash light goes on. Our observation was if we remove SD Card and nothing is flashed in nand also, In short no firmware is in picture, then Flash light line stays high permantly.
Also we checked datasheet. this pin's reset state is low.
BALL NUMBER : Y11
BALL NAME : GPMC_BE[1]
Alternate Function: GPMC_BE[1]/GPMC_A[24]/EDMA_EVT1/TIM7_IO/GP1[30]
PINCNTL REGISTER NAME AND ADDRESS : PINCNTL132 / 0x4814 0A0C
PINCNTL DEFAULT VALUE : 0x0004 0000
BALL RESET STATE : L
POWER : DVDD_GPMC
Is that the case ROM code of DM385 uses this PAD and making it high, because if no u-boot is running and board is just powered up then why this line goes high?
Can anyone have look on this?
Regards,
Vismay