topic Re: imx6solo kernel reset gpio in i.MX Processors

imx6solo kernel reset gpio

1182614726 — Mon, 15 Apr 2019 06:06:45 GMT

大家好，

目前使用imx6solo芯片，bsp 为 yocto L4.1.15-2.1.10.

目前发现，在uboot控制的GPIO为高电平，在kernel初始化时，测量会出现一个3ms的低电平。这个gpio是控制背光的pwm，导致logo在显示过渡阶段会出现闪烁。

请问这是怎么回事呢？是在kernel启动阶段复位了gpio吗？或者有什么办法可以不让kernel复位gpio吗？

谢谢各位大神鼎力相助。

Re: imx6solo kernel reset gpio

Yuri — Mon, 15 Apr 2019 09:27:53 GMT

Hello,

Generally the kernel does not change pin states, except those

pins, that are needed for device (driver) operation. Such initialization

in implemented in init section of corresponding drivers.

Have a great day,
Yuri

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Re: imx6solo kernel reset gpio

1182614726 — Mon, 15 Apr 2019 09:37:30 GMT

Hi Yuri，

now bsp can display logo from uboot to kernel via lvds. So I want keep the backligt allows on. but now the backlight pwm pin when goes into kernel state，it will use for backlight child-system. because we will to change brightness after QT. So can you help me how to do？

Re: imx6solo kernel reset gpio

Yuri — Mon, 15 Apr 2019 09:41:34 GMT

Hi,

check Your backlight driver regarding pwm initialization - if it provides the reset.

~Yuri.

Re: imx6solo kernel reset gpio

1182614726 — Mon, 15 Apr 2019 09:52:19 GMT

Hi Yuri,

Thank you very much! I have remove the brightness update in backlight driver, now the problem has been solved!

^_^