linux-kernel - Re: [PATCH 3/4] include: dt-bindings: Add more GPIO bank and index definition for rockchip pinctrl

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: <b8fd0df8-5f5b-b699-e4c9-fea7387b8277@rock-chips.com>
Date:   Tue, 6 Sep 2016 17:33:53 +0800
From:   Andy Yan <andy.yan@...k-chips.com>
To:     Heiko Stuebner <heiko@...ech.de>
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-rockchip@...ts.infradead.org, robh+dt@...nel.org,
        mark.rutland@....com, linux@...linux.org.uk,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 3/4] include: dt-bindings: Add more GPIO bank and index
 definition for rockchip pinctrl

Hi Heiko:


On 2016年09月06日 06:10, Heiko Stuebner wrote:
> Am Montag, 5. September 2016, 18:22:46 CEST schrieb Andy Yan:
>> Hi Heiko:
>>
>> On 2016年09月05日 17:33, Heiko Stuebner wrote:
>>> Hi Andy,
>>>
>>> Am Sonntag, 4. September 2016, 16:35:30 CEST schrieb Andy Yan:
>>>> There are 8 gpio banks on RK3288, so add the missing
>>>> RK_GPIO7 and RK_GPIO8. Also add gpio index definition
>>>> to make it easier to description GPIO in dts.
>>>>
>>>> Signed-off-by: Andy Yan <andy.yan@...k-chips.com>
>>> I tend to disagree here.
>>>
>>> I consider the bank defines RK_GPIOx to be deprecated and highly
>>> discourage
>>> them being used in new boards. They only encode the same number again (2
>>> ->
>>> RK_GPIO2 etc) and therefore don't bring any useful addition over using the
>>> bank number directly.
>>>
>>> Slightly similar argument for the per-pin defines. While the external pins
>>> are described in the A/B/C/Dx notation for pinmux purposes, the gpio
>>> controllers on top use a regular 0-31 numbering. Also you cannot name
>>> constants generic GPIO_x, simply because that may conflict with other
>>> overly generic constant names.
>>>
>>> So I'm not yet convinced that these improve readability, but they would
>>> definitly need a RK_* prefix to make them specific.
>>>
>>>
>>> Heiko
>>           I consider for a people who doesn't familiar with rockchip
>> pinctrl, He
>>    may don't know what does these number 2/4/17....stands for in the dts
>> like
>>    rockchip,pins = <2 17 RK_FUNC_GPIO &pcfg_pull_up>.
> That person shouldn't work on devicetrees anyway :-) ... or simply read the
> dt-binding for the pinctrl at first ... which should normally really be the
> first step, otherwise we wouldn't need the binding documentation.

     It's true that people who wants to develop in the kernel should 
know the technical detail  as much as possible.
But I still thinks it's a good thing if we can write code more clearly 
to  let people know what it stands for at first sight.
>>           But if we use meaningful macro here like : rockchip,pins =
>> <RK_GPIO2 RK_GPIO_C0 RK_FUNC_GPIO &pcfg_pull_up>, I think it easier to
>> tell people this GPIO is GPIO_C0 of BNAK2.
> I definitly don't agree for the gpio-bank number, see above .
>
>> Especially all the GPIOs in rockchip based schematic are described as
>> GPIOn_A/B/C/Dx. And it is also easier for people to directly use a macro
>> stands for 0~32 than translating A/B/C/Dx from the schematic to 0~32.
> But the pins might in fact really be helpful, but definitly need a prefix and
> maybe even distinguish between pin and gpio, aka RK_PIN_A0 etc?
>

     Anyway, very glad to see you think the pin definition is helpful, 
so let's move on.
I'll send a new version with the prefix as your suggested  like 
RK_PA/B/C/Dx.

     Thanks.
> Heiko
>
>>>> ---
>>>>
>>>>    include/dt-bindings/pinctrl/rockchip.h | 35
>>>>
>>>> ++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)
>>>>
>>>> diff --git a/include/dt-bindings/pinctrl/rockchip.h
>>>> b/include/dt-bindings/pinctrl/rockchip.h index 743e66a..fd35350 100644
>>>> --- a/include/dt-bindings/pinctrl/rockchip.h
>>>> +++ b/include/dt-bindings/pinctrl/rockchip.h
>>>> @@ -24,6 +24,41 @@
>>>>
>>>>    #define RK_GPIO3	3
>>>>    #define RK_GPIO4	4
>>>>    #define RK_GPIO6	6
>>>>
>>>> +#define RK_GPIO7	7
>>>> +#define RK_GPIO8	8
>>>> +
>>>> +#define GPIO_A0		0
>>>> +#define GPIO_A1		1
>>>> +#define GPIO_A2		2
>>>> +#define GPIO_A3		3
>>>> +#define GPIO_A4		4
>>>> +#define GPIO_A5		5
>>>> +#define GPIO_A6		6
>>>> +#define GPIO_A7		7
>>>> +#define GPIO_B0		8
>>>> +#define GPIO_B1		9
>>>> +#define GPIO_B2		10
>>>> +#define GPIO_B3		11
>>>> +#define GPIO_B4		12
>>>> +#define GPIO_B5		13
>>>> +#define GPIO_B6		14
>>>> +#define GPIO_B7		15
>>>> +#define GPIO_C0		16
>>>> +#define GPIO_C1		17
>>>> +#define GPIO_C2		18
>>>> +#define GPIO_C3		19
>>>> +#define GPIO_C4		20
>>>> +#define GPIO_C5		21
>>>> +#define GPIO_C6		22
>>>> +#define GPIO_C7		23
>>>> +#define GPIO_D0		24
>>>> +#define GPIO_D1		25
>>>> +#define GPIO_D2		26
>>>> +#define GPIO_D3		27
>>>> +#define GPIO_D4		28
>>>> +#define GPIO_D5		29
>>>> +#define GPIO_D6		30
>>>> +#define GPIO_D7		31
>>>>
>>>>    #define RK_FUNC_GPIO	0
>>>>    #define RK_FUNC_1	1
>
>
>
>