Re: [net-next PATCH v3 4/5] net: phy: Introduce fwnode_get_phy_id()

[Jeremy Linton <jeremy.linton@arm.com>]

Hi,

On 5/5/20 8:29 AM, Calvin Johnson wrote:
> Extract phy_id from compatible string. This will be used by
> fwnode_mdiobus_register_phy() to create phy device using the
> phy_id.
> 
> Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
> ---
> 
> Changes in v3: None
> Changes in v2: None
> 
>   drivers/net/phy/phy_device.c | 21 +++++++++++++++++++++
>   include/linux/phy.h          |  5 +++++
>   2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 4204d49586cd..f4ad47f73f8d 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -662,6 +662,27 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id,
>   }
>   EXPORT_SYMBOL(phy_device_create);
>   
> +/* Extract the phy ID from the compatible string of the form
> + * ethernet-phy-idAAAA.BBBB.
> + */
> +int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id)
> +{
> +	const char *cp;
> +	unsigned int upper, lower;
> +	int ret;
> +
> +	ret = fwnode_property_read_string(fwnode, "compatible", &cp);
> +	if (!ret) {
> +		if (sscanf(cp, "ethernet-phy-id%4x.%4x",
> +			   &upper, &lower) == 2) {
> +			*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
> +			return 0;
> +		}


Isn't the ACPI _CID() conceptually similar to the DT compatible 
property? It even appears to be getting used in a similar way to 
identify particular phy drivers in this case.


Thanks,