Subject: Re: [PATCH 3/4] gpio: davinci: Add a separate compatible for
 keystone-k2g soc
To: Keerthy <j-keerthy@ti.com>, <linus.walleij@linaro.org>,
        <ssantosh@kernel.org>
CC: <robh+dt@kernel.org>, <s-anna@ti.com>, <fcooper@ti.com>,
        <linux-gpio@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>
References: <1500375436-9435-1-git-send-email-j-keerthy@ti.com>
 <1500375436-9435-4-git-send-email-j-keerthy@ti.com>
From: Sekhar Nori <nsekhar@ti.com>
Message-ID: <902db353-2db1-fa86-5f96-541082348a35@ti.com>
Date: Tue, 18 Jul 2017 17:01:43 +0530
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Hi Keerthy,

On Tuesday 18 July 2017 04:27 PM, Keerthy wrote:
> Add a separate compatible for keystone-k2g soc
> 
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
>  Documentation/devicetree/bindings/gpio/gpio-davinci.txt | 3 ++-
>  drivers/gpio/gpio-davinci.c                             | 1 +
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> index 5079ba7..1a5c1a2 100644
> --- a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> +++ b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
> @@ -1,7 +1,8 @@
>  Davinci/Keystone GPIO controller bindings
>  
>  Required Properties:
> -- compatible: should be "ti,dm6441-gpio", "ti,keystone-gpio"
> +- compatible: should be "ti,dm6441-gpio", "ti,keystone-gpio",
> +	      "ti,keystone-k2g-gpio"
>  
>  - reg: Physical base address of the controller and the size of memory mapped
>         registers.
> diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
> index 932f270..a8d8dd9 100644
> --- a/drivers/gpio/gpio-davinci.c
> +++ b/drivers/gpio/gpio-davinci.c
> @@ -610,6 +610,7 @@ static int davinci_gpio_irq_setup(struct platform_device *pdev)
>  static const struct of_device_id davinci_gpio_ids[] = {
>  	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
>  	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
> +	{ .compatible = "ti,keystone-k2g-gpio", keystone_gpio_get_irq_chip},

You don't have to add compatible matching to the driver if you don't
need any special handling for K2G ATM. Your dts should have:

compatible = "ti,keystone-k2g-gpio", "ti,keystone-gpio";

this way, the driver continues to probe using "ti,keystone-gpio", and
when you really discover a need to do some special handling for K2G, a
kernel update will do without the need for a DT update.

Thanks,
Sekhar