Subject: [linux-sunxi] Re: [PATCH 0/5] ARM: dts: sunxi: Add backlight node to q8 tablets

From: [email-masked] (Hans de Goede)
Date: Mon, 11 Jan 2016 12:09:12 +0100

Hi,

On 11-01-16 11:34, 8001010 wrote:
> Hans de Goede wrote:
>> Hi,
>>
>> On 21-12-15 11:56, Silvio Pellicano wrote:
>>>
>>>
>>>> Here is a slightly updated version of Chen-Yu's backlight
>>>> patches, also adding support for the backlight found on A13
>>>> based q8 tablets.
>>>>
>>>
>>> If i compile your dtsi with (obviously) pwm  support enable , backlight
>>> switch off after kernel start,
>>> if i disable pwm in menuconfig,it stay on, all seem correct (pwm on PB2 in
>>> original script.bin),
>>> but there is somewhere a bug in pwm or dtsi description of backlight.
>>
>> No there is not, if you enable the pwm driver you must also enable
>> the backlight-pwm driver / add CONFIG_BACKLIGHT_PWM=y to your .config
>> (and make sure it stays that way after a "make oldconfig").
>>
>> Regards,
>>
>> Hans
>>
> Now work, but what flag  i have to enable to leave 5v usb otg ON?
> uboot switch ON Usb Otg voltage but kernel switch off during boot (no usb devices work).

In order for otg to work you must load a gadget driver, e.g. do:

insmod libcomposite.ko
insmod u_serial.ko
insmod usb_f_acm.ko
insmod g_serial.ko

Regards,

Hans