Re: [net-next PATCH v1 3/7] net: phy: Introduce fwnode_get_phy_id()

[Grant Likely <grant.likely@arm.com>]

On 30/09/2020 17:04, 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>
> ---
> 
>   drivers/net/phy/phy_device.c | 32 +++++++++++++++++++++++++++++++-
>   include/linux/phy.h          |  5 +++++
>   2 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index c4aec56d0a95..162abde6223d 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -9,6 +9,7 @@
>   
>   #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>   
> +#include <linux/acpi.h>
>   #include <linux/bitmap.h>
>   #include <linux/delay.h>
>   #include <linux/errno.h>
> @@ -845,6 +846,27 @@ static int get_phy_c22_id(struct mii_bus *bus, int addr, u32 *phy_id)
>   	return 0;
>   }
>   
> +/* 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)
> +{
> +	unsigned int upper, lower;
> +	const char *cp;
> +	int ret;
> +
> +	ret = fwnode_property_read_string(fwnode, "compatible", &cp);
> +	if (ret)
> +		return ret;
> +
> +	if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
> +		*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
> +		return 0;
> +	}
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL(fwnode_get_phy_id);

This block, and the changes in patch 4 duplicate functions from 
drivers/of/of_mdio.c, but it doesn't refactor anything in 
drivers/of/of_mdio.c to use the new path. Is your intent to bring all of 
the parsing in these functions of "compatible" into the ACPI code path?

If so, then the existing code path needs to be refactored to work with 
fwnode_handle instead of device_node.

If not, then the DT path in these functions should call out to of_mdio, 
while the ACPI path only does what is necessary.

> +
>   /**
>    * get_phy_device - reads the specified PHY device and returns its @phy_device
>    *		    struct
> @@ -2866,7 +2888,15 @@ EXPORT_SYMBOL_GPL(device_phy_find_device);
>    */
>   struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode)
>   {
> -	return fwnode_find_reference(fwnode, "phy-handle", 0);
> +	struct fwnode_handle *phy_node;
> +
> +	phy_node = fwnode_find_reference(fwnode, "phy-handle", 0);
> +	if (is_acpi_node(fwnode) || !IS_ERR(phy_node))
> +		return phy_node;
> +	phy_node = fwnode_find_reference(fwnode, "phy", 0);
> +	if (IS_ERR(phy_node))
> +		phy_node = fwnode_find_reference(fwnode, "phy-device", 0);
> +	return phy_node;
>   }
>   EXPORT_SYMBOL_GPL(fwnode_get_phy_node);
>   
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 7b1bf3d46fd3..b6814e04092f 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -1378,6 +1378,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id,
>   				     bool is_c45,
>   				     struct phy_c45_device_ids *c45_ids);
>   #if IS_ENABLED(CONFIG_PHYLIB)
> +int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id);
>   struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode);
>   struct phy_device *device_phy_find_device(struct device *dev);
>   struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode);
> @@ -1385,6 +1386,10 @@ struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);
>   int phy_device_register(struct phy_device *phy);
>   void phy_device_free(struct phy_device *phydev);
>   #else
> +static inline int fwnode_get_phy_id(struct fwnode_handle *fwnode, u32 *phy_id)
> +{
> +	return 0;
> +}
>   static inline
>   struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode)
>   {
>