From: gregory.clement@free-electrons•com (Gregory CLEMENT)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/6] pinctrl: armada-37xx: Add gpio support
Date: Wed, 22 Mar 2017 12:54:50 +0100 [thread overview]
Message-ID: <874lylfrw5.fsf@free-electrons.com> (raw)
In-Reply-To: <CACRpkdY_68=5oBN3TLs_ohc0gc2=yiG3qizg7MGh4F7Z+-ZzSg@mail.gmail.com> (Linus Walleij's message of "Fri, 30 Dec 2016 09:51:51 +0100")
Hi Linus,
On ven., d?c. 30 2016, Linus Walleij <linus.walleij@linaro•org> wrote:
> On Thu, Dec 22, 2016 at 6:24 PM, Gregory CLEMENT
> <gregory.clement@free-electrons•com> wrote:
>
>> GPIO management is pretty simple and is part of the same IP than the pin
>> controller for the Armada 37xx SoCs. This patch adds the GPIO support to
>> the pinctrl-armada-37xx.c file, it also allows sharing common functions
>> between the gpiolib and the pinctrl drivers.
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons•com>
>
> Some remarks:
>
>> +static int armada_37xx_gpio_get_direction(struct gpio_chip *chip,
>> + unsigned int offset)
>> +{
>> + struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
>> + unsigned int reg = OUTPUT_EN;
>> + unsigned int val, mask;
>> +
>> + if (offset >= GPIO_PER_REG) {
>> + offset -= GPIO_PER_REG;
>> + reg += sizeof(u32);
>> + }
>
> Add a comment saying we never have more than two registers?
> If there would be three registers this would fail, right?
I added the comment
>
>> + mask = BIT(offset);
>> +
>> + regmap_read(info->regmap, reg, &val);
>>
>> + return (val & mask) == 0;
>
> Use this:
>
> return !(val & mask);
done but I could tou explain the advantage of doing it?
>
>> +static int armada_37xx_gpio_get(struct gpio_chip *chip, unsigned int offset)
>> +{
>> + struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
>> + unsigned int reg = INPUT_VAL;
>> + unsigned int val, mask;
>> +
>> + if (offset >= GPIO_PER_REG) {
>> + offset -= GPIO_PER_REG;
>> + reg += sizeof(u32);
>> + }
>> + mask = BIT(offset);
>
> This code is repeating. Break out a static (inline?) helper to do
> this.
done
>
>> +static int armada_37xx_gpiolib_register(struct platform_device *pdev,
>> + struct armada_37xx_pinctrl *info)
>
> Nit: gpiochip_register or so is more to the point.
>
>> + ret = gpiochip_add_pin_range(&info->gpio_chip, dev_name(dev), 0,
>> + pinbase, info->data->nr_pins);
>> + if (ret)
>> + return ret;
>
> Why do you do this?
>
> Why not just put the ranges into the device tree? We already support
> this in the gpiolib core and it is helpful.
>
> See Documentation/devicetree/bindings/gpio/gpio.txt
> and other DTS files for gpio-ranges.
Following your review, I tried to use it but it didn't work for
me. When the second pin controller was probed then there was collision
for the gpio number. I tried several combination without any luck.
So for now I left it aside.
I can show you the errors message I get and the binding I used if you
are interested.
Thanks,
Gregory
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2017-03-22 11:54 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-22 17:24 [PATCH 0/6] Add support for pinctrl/gpio on Armada 37xx Gregory CLEMENT
2016-12-22 17:24 ` [PATCH 1/6] pinctrl: dt-bindings: Add documentation for Armada 37xx pin controllers Gregory CLEMENT
2016-12-30 8:35 ` Linus Walleij
2017-03-22 11:42 ` Gregory CLEMENT
2016-12-22 17:24 ` [PATCH 2/6] pinctrl: armada-37xx: Add pin controller support for Armada 37xx Gregory CLEMENT
2016-12-30 8:44 ` Linus Walleij
2017-03-22 11:47 ` Gregory CLEMENT
2016-12-22 17:24 ` [PATCH 3/6] pinctrl: armada-37xx: Add gpio support Gregory CLEMENT
2016-12-30 8:51 ` Linus Walleij
2017-03-22 11:54 ` Gregory CLEMENT [this message]
2017-03-23 10:28 ` Linus Walleij
2017-03-23 14:47 ` Gregory CLEMENT
2016-12-22 17:24 ` [PATCH 4/6] pinctrl: aramda-37xx: Add irqchip support Gregory CLEMENT
2016-12-30 8:58 ` Linus Walleij
2017-03-22 12:02 ` Gregory CLEMENT
2017-03-23 10:36 ` Linus Walleij
2017-03-23 14:41 ` Gregory CLEMENT
2016-12-22 17:25 ` [PATCH 5/6] ARM64: dts: marvell: Add pinctrl nodes for Armada 3700 Gregory CLEMENT
2016-12-22 17:25 ` [PATCH 6/6] ARM64: dts: marvell: armada37xx: add pinctrl definition Gregory CLEMENT
2016-12-30 9:00 ` Linus Walleij
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