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

From: Andy Yan <andy.yan@rock-chips.com>
To: Heiko Stuebner <heiko@sntech.de>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-rockchip@lists.infradead.org, robh+dt@kernel.org,
	mark.rutland@arm.com, linux@armlinux.org.uk,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 3/4] include: dt-bindings: Add more GPIO bank and index definition for rockchip pinctrl
Date: Mon, 5 Sep 2016 18:22:46 +0800	[thread overview]
Message-ID: <0dbac4cd-7f67-5052-16e6-463896bf5929@rock-chips.com> (raw)
In-Reply-To: <3544284.90s5nXbktR@phil>

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@rock-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>.
         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.
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.
>> ---
>>
>>   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
>
>
>
>