linux-kernel - Re: [PATCH 1/2] dts: display5: Device tree description of LWN's DISPLAY5 board

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <3537f09b-be9d-0b43-0bec-87d08b43312f@denx.de>
Date:   Wed, 20 Sep 2017 11:45:12 +0200
From:   Łukasz Majewski <lukma@...x.de>
To:     Fabio Estevam <festevam@...il.com>
Cc:     "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        Mark Rutland <mark.rutland@....com>,
        Russell King <linux@...linux.org.uk>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Sascha Hauer <kernel@...gutronix.de>,
        Fabio Estevam <fabio.estevam@....com>,
        Shawn Guo <shawnguo@...nel.org>
Subject: Re: [PATCH 1/2] dts: display5: Device tree description of LWN's
 DISPLAY5 board

Hi Fabio,

> Hi Lukasz,
> 
> On Wed, Sep 20, 2017 at 6:22 AM, Łukasz Majewski <lukma@...x.de> wrote:
> 
>> Could you be more specific here?
>>
>> The 0x80000000 corresponds to IMX_NO_PAD_CTL in pinctrl-imx.c, which
>> prevents from manual GPIO control.
>>
>> The 0x80000000 value is the IOMUXC_SW_PAD_CTL_PAD_CSI0_DATA11 (0x020E_0654)
>> config data (16 bits only -> 0x0).
>>
>> Writing 0x0 to this register is perfectly fine for my application.
>>
>>
>> I'm a bit in doubt to what I shall do more?
> 
> As per the Reference Manual, the POR reset for
> IOMUXC_SW_PAD_CTL_PAD_CSI0_DATA11 is 0x1b0b0.
> 
> 0x80000000 tells the kernel to not touch this IOMUX and use whatever
> value comes from the bootloader.
> 
> If your bootloader does not touch this register, then you probably
> read 0x1b0b0 from it.
> 
> In this case, please do this instead:
> 
> MX6QDL_PAD_CSI0_DAT11__GPIO5_IO29 0x1b0b0
> 

Ok. Thanks for explanation :-)


-- 
Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@...x.de