Subject: [PATCH] I2C: BCM2835: Linking platform nodes to adapter nodes

From: [email-masked] (Stephen Warren)
Date: Fri, 08 Nov 2013 09:59:28 -0700

On 11/08/2013 02:49 AM, Florian Meier wrote:
> In order to find I2C devices in the device tree, the platform nodes
> have to be known by the I2C core. Analogous to the i2c-omap driver
> this requires setting the dev.of_node parameter of the adapter.

(CCing the I2C maintainers...)

> diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c

> @@ -299,6 +299,7 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
>  	strlcpy(adap->name, "bcm2835 I2C adapter", sizeof(adap->name));
>  	adap->algo = &bcm2835_i2c_algo;
>  	adap->dev.parent = &pdev->dev;
> +	adap->dev.of_node = pdev->dev.of_node;

Ah, that makes sense. Thinking about it now, I'd only ever used i2cget
etc. to access I2C devices, rather than instantiating drivers from DT.

That all said, I wonder if the I2C core shouldn't do something like the
following inside i2c_add_adapter():

if (!adap->dev.of_node && adap->dev.parent)
	adap->dev.of_node = adap->dev.parent->of_node;

That would save every single I2C driver from having to set up this field
manually.