linux-kernel - Re: [PATCH v2 02/10] pinctrl: axp209: add pinctrl features

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

Message-ID: <0bc7efe6-8d0e-ddae-617b-36e4357f76ce@free-electrons.com>
Date:   Tue, 26 Sep 2017 15:37:37 +0200
From:   Quentin Schulz <quentin.schulz@...e-electrons.com>
To:     Maxime Ripard <maxime.ripard@...e-electrons.com>
Cc:     linus.walleij@...aro.org, robh+dt@...nel.org, mark.rutland@....com,
        wens@...e.org, linux@...linux.org.uk, lee.jones@...aro.org,
        linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-sunxi@...glegroups.com, thomas.petazzoni@...e-electrons.com
Subject: Re: [PATCH v2 02/10] pinctrl: axp209: add pinctrl features

On 26/09/2017 15:27, Maxime Ripard wrote:
> On Tue, Sep 26, 2017 at 01:08:21PM +0000, Quentin Schulz wrote:
>> Hi Maxime,
>>
>> On 26/09/2017 15:00, Maxime Ripard wrote:
>>> On Tue, Sep 26, 2017 at 12:17:12PM +0000, Quentin Schulz wrote:
>>>> +static const struct axp20x_desc_pin axp209_pins[] = {
>>>> +	AXP20X_PIN(AXP20X_PINCTRL_PIN(0, "GPIO0"),
>>>> +		   AXP20X_FUNCTION(0x0, "gpio_out"),
>>>> +		   AXP20X_FUNCTION(0x2, "gpio_in"),
>>>> +		   AXP20X_FUNCTION(0x3, "ldo"),
>>>> +		   AXP20X_FUNCTION(0x4, "adc")),
>>>> +	AXP20X_PIN(AXP20X_PINCTRL_PIN(1, "GPIO1"),
>>>> +		   AXP20X_FUNCTION(0x0, "gpio_out"),
>>>> +		   AXP20X_FUNCTION(0x2, "gpio_in"),
>>>> +		   AXP20X_FUNCTION(0x3, "ldo"),
>>>> +		   AXP20X_FUNCTION(0x4, "adc")),
>>>> +	AXP20X_PIN(AXP20X_PINCTRL_PIN(2, "GPIO2"),
>>>> +		   AXP20X_FUNCTION(0x0, "gpio_out"),
>>>> +		   AXP20X_FUNCTION(0x2, "gpio_in")),
>>>> +};
>>>
>>> If all the functions are the same, and at the same offset, can't we
>>> just hardcode it, instead of having (and duplicate) all the logic
>>> below?
>>>
>>
>> AXP20X_PIN(AXP20X_PINCTRL_PIN(0, "GPIO0"),
>> 		AXP20X_GPIO_OUT,
>> 		AXP20X_GPIO_IN,
>> 		AXP20X_LDO,
>> 		AXP20X_ADC))
>>
>> That's what you mean?
> 
> What I mean is:
> 
> static int axp20x_get_func(char *func)
> {
> 	if (!strcmp(func, "gpio_out"))
> 		return 0;
> 
> 	if (!strcmp(func, "gpio_in"))
> 		return 2;
>  
> 	if (!strcmp(func, "ldo"))
>  		return 3;
>  
> 	if (!strcmp(func, "adc"))
>  		return 4;
> 
> 	return -EINVAL;
> }
> 

GPIO2 on AXP209 does not support ldo nor adc.
GPIO1 on AXP813 does not support adc.

I find it more complex to handle those two cases in a function than by
hardcoding it in structures like above.

Moreover, nothing tells us that it would be the same offset for other PMICs.

Quentin
-- 
Quentin Schulz, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com



Download attachment "signature.asc" of type "application/pgp-signature" (802 bytes)