how to config the gpio default power on state by edit imximage.cfg in the uboot code

[bigjiong]

HI all:

    I am using the M6Y2C-512F4GLI-T SOM board, the link is https://www.zlg.cn/index.php/ipc/ipc/product/id/238.html

    I use the MX6_PAD_SD1_CMD as GPIO2_IO16  (output use, low level default)

            and MX6_PAD_SD1_DATA0 as GPIO2_IO18  (output use, low level default)

    I found that when the mpu (power on) or (reset), this two pin output the high level.

    I want them output the low level by default,

         so I edit the int board_init(void) function,

              add the function:

                                     1) gpio_request()

                                     2) gpio_direction_output()

              it work fine, However, there is still a two-second delay from system power-on or reboot.

              In other words, there will be a high level output for two seconds.

/*

 * Device Configuration Data (DCD)

 *

 * Each entry must have the format:

 * Addr-type           Address        Value

 *

 * where:

 *  Addr-type register length (1,2 or 4 bytes)

 *  Address   absolute address of the register

 *  value     value to be stored in the register

 */

    This is part of the description in the imximage.cfg file.

    So I want to modify this file, And add something like this type:

    

DATA 4 Address(MUX_CTL_PAD_SD1_CMD_ADDRESS) value(MUX_CTL_PAD_SD1_CMD_VALUE)

AND I have already get the register value generate by the software which named Config_Tools_for_i.MX_v14_x64.exe

this is the register value:

#define BOARD_INITPINS_IOMUXC_SW_MUX_CTL_PAD_SD1_CMD_VALUE                      0x00000015   /*!< Register name: IOMUXC_SW_MUX_CTL_PAD_SD1_CMD */

#define BOARD_INITPINS_IOMUXC_SW_PAD_CTL_PAD_SD1_CMD_VALUE                      0x000010B0   /*!< Register name: IOMUXC_SW_PAD_CTL_PAD_SD1_CMD */

Can anyone tell me how to get the absolute address of the register or where to.

Thanks.

[AldoG · Accepted solution]

Hello,

You may find these registers in the processor reference manual, which is the i.MX6ULL.

32.6.95 SW_MUX_CTL_PAD_SD1_CMD SW MUX Control Register (IOMUXC_SW_MUX_CTL_PAD_SD1_CMD)
Address: 20E_0000h base + 1BCh offset = 20E_01BCh

32.6.241 SW_PAD_CTL_PAD_SD1_CMD SW PAD Control Register (IOMUXC_SW_PAD_CTL_PAD_SD1_CMD)
Address: 20E_0000h base + 448h offset = 20E_0448h

Saludos,
Aldo.

[bigjiong]

Thanks for your reply @AldoG!

I have add this code to the imximage.cfg:

DATA 4 0x020E01BC 0x00000005

DATA 4 0x020E0448 0x000010B0

but there still have a high level output for two seconds 

It seems that there should be other instructions interfering with the operation.

and I have try to add the code to the plugin.S file as below.

.macro imx6_qos_setting

    ldr r0, =0x020E0000

    ldr r1, =0x00000005

    str r1, [r0, #0x1BC]

    ldr r1, =0x000030B0

    str r1, [r0, #0x448]

.endm

The above code is called in mx6_plugin.S, like this:

plugin_start:

    push    {r0-r4, lr}

    imx6_ddr_setting

    imx6_clock_gating

    imx6_qos_setting   /* <----   the code Call place */

Some code related to SD1 peripheral initialization may need to be commented out.

I will try to find out them.

because of The file type (.cfg and .S) is not supported to upload, I have compress those files (imximage.cfg and plugin.S) to a single .zip file.

Saludos,

bigjiong.

[bigjiong]

I have add this code to the imximage.cfg, but there still have a high level output for two seconds.

DATA 4 0x020E01BC 0x00000005

DATA 4 0x020E01C4 0x00000005

DATA 4 0x020E0448 0x000010B0

DATA 4 0x020E0450 0x000010B0