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Subject: Re: [PATCH v1 1/1] gpiolib: Read "gpio-line-names" from a firmware
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To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Roman Guskov <rguskov@dh-electronics.com>
References: <20210305120240.42830-1-andriy.shevchenko@linux.intel.com>
From:   Marek Vasut <marex@denx.de>
Message-ID: <506c1e48-c648-69d4-8e4f-b42fe02156f7@denx.de>
Date:   Fri, 5 Mar 2021 13:11:39 +0100
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On 3/5/21 1:02 PM, Andy Shevchenko wrote:
> On STM32MP1, the GPIO banks are subnodes of pin-controller@50002000,
> see arch/arm/boot/dts/stm32mp151.dtsi. The driver for
> pin-controller@50002000 is in drivers/pinctrl/stm32/pinctrl-stm32.c
> and iterates over all of its DT subnodes when registering each GPIO
> bank gpiochip. Each gpiochip has:
> 
>    - gpio_chip.parent = dev,
>      where dev is the device node of the pin controller
>    - gpio_chip.of_node = np,
>      which is the OF node of the GPIO bank
> 
> Therefore, dev_fwnode(chip->parent) != of_fwnode_handle(chip.of_node),
> i.e. pin-controller@50002000 != pin-controller@50002000/gpio@5000*000.
> 
> The original code behaved correctly, as it extracted the "gpio-line-names"
> from of_fwnode_handle(chip.of_node) = pin-controller@50002000/gpio@5000*000.
> 
> To achieve the same behaviour, read property from the firmware node.
> 
> Fixes: 7cba1a4d5e162 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
> Reported-by: Marek Vasut <marex@denx.de>
> Reported-by: Roman Guskov <rguskov@dh-electronics.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Tested-by: Marek Vasut <marex@denx.de>
Reviewed-by: Marek Vasut <marex@denx.de>

Thanks

>   static int devprop_gpiochip_set_names(struct gpio_chip *chip)
>   {
>   	struct gpio_device *gdev = chip->gpiodev;
> -	struct device *dev = chip->parent;
> +	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);

You could make the order here a reverse xmas tree, but that's a nitpick.

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