Re: [PATCH v7 5/7] iio: adc: mcp3911: Add support for spi-device-addr

Conor Dooley <[email protected]> Wed, 22 Jul 2026 17:41:54 +0100

Newsgroups	org.kernel.vger.linux-spi,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-doc,org.kernel.vger.linux-iio,org.kernel.vger.linux-kernel
Message-ID	<20260722-quickly-drone-6a2a3b79249d@spud>

On Wed, Jul 22, 2026 at 09:54:17AM +0200, Janani Sunil wrote:
> Read the generic spi-device-addr property when determining the hardware
> device address. Fall back to the deprecated microchip,device-addr
> property and then to the historical device-addr property to preserve
> compatibility with existing devicetrees.
> 
> The device address remains 0 when none of the properties are present.
> 
> Signed-off-by: Janani Sunil <[email protected]>
> ---
>  drivers/iio/adc/mcp3911.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
> index ddc3721f3f68..3919a326b4db 100644
> --- a/drivers/iio/adc/mcp3911.c
> +++ b/drivers/iio/adc/mcp3911.c
> @@ -740,10 +740,13 @@ static int mcp3911_probe(struct spi_device *spi)
>  	}
>  
>  	/*
> -	 * Fallback to "device-addr" due to historical mismatch between
> -	 * dt-bindings and implementation.
> +	 * Fall back to the vendor-specific property, then to "device-addr"
> +	 * due to a historical mismatch between the binding and implementation.

Jaysus, bit of a mess here.
Reviewed-by: Conor Dooley <[email protected]>

>  	 */
> -	ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
> +	ret = device_property_read_u32(dev, "spi-device-addr", &adc->dev_addr);
> +	if (ret)
> +		ret = device_property_read_u32(dev, "microchip,device-addr",
> +					       &adc->dev_addr);
>  	if (ret)
>  		device_property_read_u32(dev, "device-addr", &adc->dev_addr);
>  	if (adc->dev_addr > 3) {
> 
> -- 
> 2.43.0
>

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