imx8mm evk gpt driver

[andyli]

hi 

   my using board is imx8mm evk, need to use GPT to create interrupt every 1ms to do my IRS,

   I have some questions.

  1, it has 6 GPT, whether it is all the same, customer can use any one

   2.kernel 4.9.124, it can not support imx8 GPT in the file of timer-imx-gpt.c. at last I found that it is  using imx7d_timer, 

it is compatible with "mx7d_timer, "fsl,imx7d-gpt"

    gpt1: gpt@302d0000 {
        compatible = "fsl,imx8mq-gpt", "fsl,imx7d-gpt";

 in timer_imx_gpt.c CLOCKSOURCE_OF_DECLEAR(mx7d_time,fsl,imx7d-gpt,imx6dl_timer_init_dt)

my question is imx8 timer using imx6 driver in the timer-imx-gpt.c.

3. I grep the fsl-imx8mm.dtsi, fsl-imx8mm_evk.dts, it can not config the gpt, how to config gpt in dts

4. could you give me some example about gpt,  how to test it can work well.

[edcloudcycle]

Hi @igorpadykov 

I would also like to use the gpt under Linux. Is there a way to do it? It seems like a driver is present in the kernel. 

Thanks
Ed

[igorpadykov]

Hi andyli

>1, it has 6 GPT, whether it is all the same, customer can use any one

all the same

> 2..my question is imx8 timer using imx6 driver in the timer-imx-gpt.c.

yes

>3. I grep the fsl-imx8mm.dtsi, fsl-imx8mm_evk.dts, it can not config the gpt, how to config gpt in dts
>4. could you give me some example about gpt, how to test it can work well.

gpt is used by M4 core, please refer to SDK_EVK-MIMX8MM folder ../driver/examples/gpt

https://mcuxpresso.nxp.com/en/welcome

also may be useful:

https://community.nxp.com/t5/i-MX-Processors/GPT-capture-sample-on-M4-seems-to-hang-on-Linux-boot/m-...

Best regards
igor

[andyli]

hello igor
        It has the configuration of GPT in kernel 4.x version in file Fsl-imx8mq.dtsi, but it has been removed in Kernel5.4. I wonder why.
Can you give me an idea of how GPT should be used in i.mx8mm evk.

[aaron_zeng]

hello igor

I saw the comments at “timer-imx-gpt.c”  which in L5.4.24-2.1.0：

/*
 * There are 4 versions of the timer hardware on Freescale MXC hardware.
 *  - MX1/MXL
 *  - MX21, MX27.
 *  - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0)
 *  - MX6DL, MX6SX, MX6Q(rev1.1+)
 */

Any patch for imx8m ？

[andyli]

HI 

   thanks for reply so fast

   "gpt is used by M4 core" means that no gpt modules in A53 core. 

    is it right or wrong?