IMX8QXP,How to set gpio by register

[shalanyang]

HI ALL, 

            IMX8QXP, How to set by register,for example GPIO1_20.

            by datasheet:

            7.2.2.3.2 GPIO Write Mode
The programming sequence for driving output signals should be as follows:
1. Configure IOMUX to select GPIO mode (Via IOMUXC), also enable SION if need
to read loopback pad value through PSR
2. Configure GPIO direction register to output (GPIO_GDIR[GDIR] set to 1b).
3. Write value to data register (GPIO_DR).
A pseudocode description to drive 4'b0101 on [output3:output0] is as follows:
// SET PADS TO GPIO MODE VIA IOMUX. 
i.MX 8DualXPlus/8QuadXPlus Applications Processor Reference Manual, Rev. A, 6/2017

write sw_mux_ctl_pad_<output[0-3]>.mux_mode, <GPIO_MUX_MODE>
// Enable loopback so we can capture pad value into PSR in output mode 
write sw_mux_ctl_pad_<output[0-3]>.sion, 1
// SET GDIR=1 TO OUTPUT BITS. 
write GDIR[31:4,output3_bit,output2_bit, output1_bit, output0_bit,] 32'hxxxxxxxF
// WRITE OUTPUT VALUE=4’b0101 TO DR. 
write DR, 32'hxxxxxxx5
// READ OUTPUT VALUE FROM PSR ONLY. 
read_cmp PSR, 32'hxxxxxxx5
General Purpose Input/Output (GPIO)

I want to configure SC_P_FLEXCAN2_TX to GPIO,  now ,I found how to config GPIO_DR GPIO_GDIR GPIO_PSR, 

as follow code:

base: 0x5D09_0000

GPIO_DR addr:0x5D090000 value:0x5C16600D

GPIO_GDIR addr:0x5D090004 value:0x1C156000

GPIO_PSR addr:0x5D090008 value:0x5C16600D

but I can not find the IOMUXC control register address? could you help me ?

by the IMX8DQXPRM_Rev_A.pdf datasheet ,I try to access the iomux base , but have these error

135|@nutshell:/ # ./var/memtool -r 0x33F80000 0x0
[ 2384.218394] Unhandled fault: synchronous external abort (0x92000210) at 0x0000ffff9e21c000
Bus error 

why? who can tell me ? (my BSP version:L4.9.51_8qm-beta2/8qxp-beta)

[igorpadykov]

Hi shalan

as MX8QXP is not publicly released yet, there is no regular support for its software and

on below link memtool has not MX8 files:

memtool\test - imx-test - i.MX Driver Test Application Software 

General way to set gpio - is to use api, please check sources on

pad\svc\sc\imx\soc\drivers - linux-imx - i.MX Linux kernel 

use function sc_pad_set_mux(), config as SC_PAD_CONFIG_NORMAL

api.h\pad\svc\sc\imx8\soc\include - linux-imx - i.MX Linux kernel 

Best regards
igor
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[shalanyang]

Hi ，igorpadykov,

        first， thanks for you answer, we have a program with imx8qxp for meter, Iwe hope uboot startup very fast an fast,

but when power on before the console show logo, it is spend about 236 ms,so I want to know why  the first stage in uboot spend so much time, so I want to configure gpio1_20 by register ,then I can test the time by  Oscilloscope ,the logo is follow:

power ON:

[ 0.236] U-Boot 2017.03-00644-ge2936712ab-dirty (May 08 2018 - 11:30:38 +0800)

[ 0.243] CPU: Freescale i.MX8QXP revA A35 at 1200 MHz at 41C
[ 0.274] Model: Freescale i.MX8QXP LPDDR4 ARM2
[ 0.278] Board: iMX8QXP LPDDR4 ARM2
[ 0.282] Boot: MMC0
[ 0.284] DRAM: 3 GiB
board_gpio_init====================TEST
[ 0.374] MMC: Actual rate for SDHC_0 is 333333333
[ 0.382] FSL_SDHC: 0
[ 0.385] Using default environment

[ 0.388] In: serial@5a060000
[ 0.391] Out: serial@5a060000
[ 0.394] Err: serial@5a060000
[ 0.398]
[ 0.399] BuildInfo:
[ 0.401] - SCFW 9f3fa3da, IMX-MKIMAGE e2936712, ATF
[ 0.407] - U-Boot 2017.03-00644-ge2936712ab-dirty

[ 0.412] Normal Boot
[ 0.558] kernle sImageHeader.imageheadinfo.ih_size=0x7aa400
[ 0.563] uieMMC_KernelAddr=0x100000, uiKernelSize=0xa47a40
[ 0.569] eMMC_kernel_block=0x800, eMMC_kernel_cnt=0x523e
[ 0.574] uieMMC_DTBAddr=0xb47a40
[ 0.579] uieMMC_DTBAddr%IAUTO_MMC_BLKSIZE=0x40
[ 0.583] DTB sImageHeader.imageheadinfo.ih_size=0xae20000
[ 0.589] uiDTBSize=0xe24a
[ 0.592] uiDTBLoadAddr = 0x82ffffc0
[ 0.595] uiDTBLoadAddr = 0x82ffff80
[ 0.600] kernle sImageHeader.imageheadinfo.ih_size=0x64732b00
[ 0.606] Hit any key to stop autoboot: 0
switch to partitions #0, OK
[ 0.729] mmc0(part 0) is current device
[ 0.733]
[ 0.734] MMC read: dev # 0, block # 2048, count 21054 ... 21054 blocks read: OK
[ 0.783]
[ 0.784] ## Checking Image at 8027ffc0 ...
[ 0.788] Legacy image found
[ 0.791] Image Name: imx8x-poc 20180508-113157
[ 0.796] Image Type: AArch64 Linux Kernel Image (uncompressed)
[ 0.803] Data Size: 10779136 Bytes = 10.3 MiB
[ 0.808] Load Address: 8027ffc0
[ 0.811] Entry Point: 80280000
[ 0.815] Verifying Checksum ... OK
[ 0.896]
[ 0.897] MMC read: dev # 0, block # 43008, count 5562 ... 5562 blocks read: OK
[ 0.917]
[ 0.918] MMC read: dev # 0, block # 23101, count 114 ... 114 blocks read: OK
[ 0.928]
[ 0.929] ## Checking Image at 82ffffc0 ...
[ 0.934] Legacy image found
[ 0.937] Image Name: imx8x-poc 20180508-113157
[ 0.942] Image Type: AArch64 Linux Kernel Image (uncompressed)
[ 0.948] Data Size: 57866 Bytes = 56.5 KiB
[ 0.953] Load Address: 00000000
[ 0.956] Entry Point: 00000000
[ 0.960] Verifying Checksum ... OK
[ 0.963] ## Loading init Ramdisk from Legacy Image at 84000000 ...
[ 0.970] Image Name: imx_imx8x 20180508-113539
[ 0.975] Image Type: AArch64 Linux RAMDisk Image (gzip compressed)
[ 0.981] Data Size: 2847588 Bytes = 2.7 MiB
[ 0.986] Load Address: 00000000
[ 0.990] Entry Point: 00000000
[ 0.993] Verifying Checksum2222 ... OK
[ 1.017] ## Flattened Device Tree blob at 83000000
[ 1.022] Booting using the fdt blob at 0x83000000
[ 1.027] Using Device Tree in place at 0000000083000000, end 0000000083011209
[ 1.090]
[ 1.091] Starting kernel ...

.....

there is any way to access the GPIO1_20 ? could you help me ?

[igorpadykov]

in uboot you can look at gpio example in enet_device_phy_reset() in

uboot/board/freescale/imx8qxp_mek/imx8qxp_mek.c

imx8qxp_mek.c\imx8qxp_mek\freescale\board - uboot-imx - i.MX U-Boot 

Best regards
igor

[shalanyang]

or like this https://mp.weixin.qq.com/s/bXbBvRTq27OmXVSZw90N8Q ,but IMX8QXP I do not know how to configure the gpio

[shalanyang]

Yes, I know this way?

        but before applay this sc_pad_set()  fuction to set gpio1_20 ,uboot startup had spend more than 200ms, so I want to know how to configure it in start.s when power on  and I want to know why spend so much time before ,so I want to configure it by register the same as IMX51+WINCE6.0基于SD_MMC启动—XLDR(3)之xldr.s | 学步园 

thanks!