linux-kernel - Re: [PATCH v1 2/2] i2c: designware: Use device_is

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Message-ID: <20260114115304.GC2275908@black.igk.intel.com>
Date: Wed, 14 Jan 2026 12:53:04 +0100
From: Mika Westerberg <mika.westerberg@...ux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
	Andi Shyti <andi.shyti@...nel.org>, Jan Dabros <jsd@...ihalf.com>
Subject: Re: [PATCH v1 2/2] i2c: designware: Use device_is_compatible()
 instead of custom approach

On Wed, Jan 14, 2026 at 09:17:51AM +0100, Andy Shevchenko wrote:
> We use MODEL_MSCC_OCELOT effectively is a flag for comparing against

as a flag?

> "compatible" property. Use device_is_compatible() directly to make it
> clear.

Okay but if something else ever needs this same quirk then we would need to
add new entry here and also to the IDs list.

With the flag you can have the IDs in a single place not all over the
driver.

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  drivers/i2c/busses/i2c-designware-common.c  | 6 +-----
>  drivers/i2c/busses/i2c-designware-core.h    | 1 -
>  drivers/i2c/busses/i2c-designware-platdrv.c | 2 +-
>  3 files changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
> index 5b1e8f74c4ac..c766d9821975 100644
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -238,14 +238,10 @@ static void i2c_dw_of_configure(struct device *device)
>  	struct platform_device *pdev = to_platform_device(device);
>  	struct dw_i2c_dev *dev = dev_get_drvdata(device);
>  
> -	switch (dev->flags & MODEL_MASK) {
> -	case MODEL_MSCC_OCELOT:
> +	if (device_is_compatible(dev->dev, "mscc,ocelot-i2c")) {
>  		dev->ext = devm_platform_ioremap_resource(pdev, 1);
>  		if (!IS_ERR(dev->ext))
>  			dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
> -		break;
> -	default:
> -		break;
>  	}
>  }
>  
> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
> index cf0364079b55..10055f0e0ec3 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -313,7 +313,6 @@ struct dw_i2c_dev {
>  #define ARBITRATION_SEMAPHORE			BIT(2)
>  #define ACCESS_POLLING				BIT(3)
>  
> -#define MODEL_MSCC_OCELOT			BIT(8)
>  #define MODEL_AMD_NAVI_GPU			BIT(10)
>  #define MODEL_WANGXUN_SP			BIT(11)
>  #define MODEL_MASK				GENMASK(11, 8)
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 2e532f16691b..4e6fe3b55322 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -267,7 +267,7 @@ static void dw_i2c_plat_remove(struct platform_device *pdev)
>  }
>  
>  static const struct of_device_id dw_i2c_of_match[] = {
> -	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
> +	{ .compatible = "mscc,ocelot-i2c" },
>  	{ .compatible = "snps,designware-i2c" },
>  	{}
>  };
> -- 
> 2.50.1