Re: [PATCH v5 1/6] drivers: phy: add generic PHY framework

From: Stephen Warren
Date: Wed Apr 03 2013 - 19:54:22 EST


On 04/03/2013 06:53 AM, Kishon Vijay Abraham I wrote:
> The PHY framework provides a set of APIs for the PHY drivers to
> create/destroy a PHY and APIs for the PHY users to obtain a reference to the
> PHY with or without using phandle. To obtain a reference to the PHY without
> using phandle, the platform specfic intialization code (say from board file)
> should have already called phy_bind with the binding information. The binding
> information consists of phy's device name, phy user device name and an index.
> The index is used when the same phy user binds to mulitple phys.
>
> PHY drivers should create the PHY by passing phy_descriptor that has
> describes the PHY (label, type etc..) and ops like init, exit, suspend, resume,
> power_on, power_off.
>
> The documentation for the generic PHY framework is added in
> Documentation/phy.txt and the documentation for the sysfs entry is added
> in Documentation/ABI/testing/sysfs-class-phy and the documentation for
> dt binding is can be found at
> Documentation/devicetree/bindings/phy/phy-bindings.txt

> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h

> +extern struct phy *devm_phy_create(struct device *dev, const char *label,
> + struct device_node *of_node, int type, struct phy_ops *ops,
> + void *priv);

Can't the function get of_node from dev->of_node?

I wonder if we shouldn't split up the registration a bit though:

A function which registers a PHY object itself. That's the function above.

A function which registers a DT-based PHY provider.

Then, the of_xlate op would be part of the PHY provider, not part of
some random PHY that happens to exist on that node. So:

struct phy {
struct device *dev;
struct module *owner;
int (*init)(struct phy *phy);
int (*exit)(struct phy *phy);
int (*suspend)(struct phy *phy);
int (*resume)(struct phy *phy);
int (*power_on)(struct phy *phy);
int (*power_off)(struct phy *phy);
};

int phy_register(struct phy *phy);

All PHY providers would use that API, whether running in a DT-base
system or not.

struct of_phy_provider {
struct device *dev;
struct phy * (*of_xlate)(struct of_phy_provider *provider,
struct of_phandle_args *args);
};

int phy_register_of_provider(struct of_phy_provider *provider);

Only DT-based PHY providers would use that API.

... or something like that?

phy_get() would do something like:

if dev->of_node:
# look up using registerd of_phy_providers
phy = phy_get_of(...)
if phy: return phy
# now look up using whatever other mapping table exists
phy = ...
return phy

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