Re: [PATCH v10 3/9] dt-bindings: phy: tegra-xusb-padctl: Add Tegra210 support

Kishon Vijay Abraham I
2016-04-25T13:48:25Z

Hi,

On Monday 18 April 2016 05:20 PM, Thierry Reding wrote:
> On Wed, Apr 06, 2016 at 07:08:24PM +0200, Thierry Reding wrote:
> [...]
>> I attached what I came up with. It extends the OF PHY provider registry
>> by allowing an additional node to be specified that if specified will
>> serve as the parent for the child lookup (and hence overrides the
>> default node that's taken from the struct device).
>>
>> It is a fairly trivial patch, and you'll notice the bulk of the changes
>> is adding the additional parameter in a number of different places. The
>> only thing I'm not quite happy about is that we start needing to pass a
>> fairly large number of arguments. But perhaps it's still okay.
>>
>> An alternative would be to make struct phy_provider embeddable into
>> driver private structures. That way they could be completely initialized
>> by a driver before being passed to the __of_phy_provider_register()
>> function (much like struct gpio_chip and others). That would be a fairly
>> intrusive change, one that I'd be willing to take on, though I'd like to
>> have Kishon's opinion on this before going ahead.
>>
>> For reference, here's what I'm imagining:
>>
>> struct foo_phy_provider {
>> struct phy_provider base;
>> ...
>> };
>>
>> int foo_probe(struct platform_device *pdev)
>> {
>> struct foo_phy_provider *priv;
>> ...
>>
>> priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>> if (!priv)
>> return -ENOMEM;
>>
>> priv->base.dev = &pdev->dev;
>> priv->base.of_xlate = foo_of_xlate;
>>
>> err = devm_of_phy_provider_register(&priv->base);
>> if (err < 0)
>> return err;
>>
>> ...
>> }
>>
>> And of course adapt the signature of the __of_phy_provider_register()
>> function and remove the allocation from it.
>>
>> Thierry
>>
>> --- >8 ---
>> From 15e5348a1a63837efd00309fdce5cda979498f77 Mon Sep 17 00:00:00 2001
>> From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> Date: Tue, 5 Apr 2016 17:17:34 +0200
>> Subject: [PATCH] phy: core: Allow children node to be overridden
>>
>> In order to more flexibly support device tree bindings, allow drivers to
>> override the container of the child nodes. By default the device node of
>> the PHY provider is assumed to be the parent for children, but bindings
>> may decide to add additional levels for better organization.
>>
>> Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>> ---
>> Documentation/phy.txt | 16 ++++++++++++++--
>> drivers/phy/phy-core.c | 27 +++++++++++++++++++++------
>> include/linux/phy/phy.h | 31 +++++++++++++++++++++----------
>> 3 files changed, 56 insertions(+), 18 deletions(-)
>
> Hi Kishon,
>
> I'd like to take this through the Tegra tree along with the remainder of
> the XUSB pad controller and XHCI patches that depend on it. The nice
> thing is that it's fairly unintrusive but gives people an easy way to
> support more flexible bindings by allowing the OF node to be overridden
> when registering the PHY provider.
>
> Are you okay with the change below? If so, could you provide an
> Acked-by? I can provide a stable branch for you to pull into the PHY
> tree that I'd like to use as a base for the remainder of the series.
> I did a fair amount of compile-testing and upon inspection the API that
> the patch modifies isn't called in many places, everyone uses the
> convenience macros. The stable branch will be helpful in fixing up any
> new users, should any appear during the development cycle.
>
> Thanks,
> Thierry
>
>> diff --git a/Documentation/phy.txt b/Documentation/phy.txt
>> index b388c5af9e72..0aa994bd9a91 100644
>> --- a/Documentation/phy.txt
>> +++ b/Documentation/phy.txt
>> @@ -31,16 +31,28 @@ should provide its own implementation of of_xlate. of_xlate is used only for
>> dt boot case.
>>
>> #define of_phy_provider_register(dev, xlate) \
>> - __of_phy_provider_register((dev), THIS_MODULE, (xlate))
>> + __of_phy_provider_register((dev), NULL, THIS_MODULE, (xlate))
>>
>> #define devm_of_phy_provider_register(dev, xlate) \
>> - __devm_of_phy_provider_register((dev), THIS_MODULE, (xlate))
>> + __devm_of_phy_provider_register((dev), NULL, THIS_MODULE, (xlate))
>>
>> of_phy_provider_register and devm_of_phy_provider_register macros can be used to
>> register the phy_provider and it takes device and of_xlate as
>> arguments. For the dt boot case, all PHY providers should use one of the above
>> 2 macros to register the PHY provider.
>>
>> +Often the device tree nodes associated with a PHY provider will contain a set
>> +of children that each represent a single PHY. Some bindings may nest the child
>> +nodes within extra levels for context and extensibility, in which case the low
>> +level of_phy_provider_register_full() and devm_of_phy_provider_register_full()
>> +macros can be used to override the node containing the children.
>> +
>> +#define of_phy_provider_register_full(dev, children, xlate) \
>> + __of_phy_provider_register(dev, children, THIS_MODULE, xlate)
>> +
>> +#define devm_of_phy_provider_register_full(dev, children, xlate) \
>> + __devm_of_phy_provider_register_full(dev, children, THIS_MODULE, xlate)
>> +
>> void devm_of_phy_provider_unregister(struct device *dev,
>> struct phy_provider *phy_provider);
>> void of_phy_provider_unregister(struct phy_provider *phy_provider);
>> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
>> index e7e574dc667a..7f7da2138c82 100644
>> --- a/drivers/phy/phy-core.c
>> +++ b/drivers/phy/phy-core.c
>> @@ -135,13 +135,19 @@ static struct phy *phy_find(struct device *dev, const char *con_id)
>> static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
>> {
>> struct phy_provider *phy_provider;
>> + struct device_node *children;
>> struct device_node *child;
>>
>> list_for_each_entry(phy_provider, &phy_provider_list, list) {
>> if (phy_provider->dev->of_node == node)
>> return phy_provider;
>>
>> - for_each_child_of_node(phy_provider->dev->of_node, child)
>> + if (!phy_provider->children)
>> + children = phy_provider->dev->of_node;
>> + else
>> + children = phy_provider->children;
>> +
>> + for_each_child_of_node(children, child)
>> if (child == node)
>> return phy_provider;
>> }
>> @@ -811,16 +817,22 @@ EXPORT_SYMBOL_GPL(devm_phy_destroy);
>> /**
>> * __of_phy_provider_register() - create/register phy provider with the framework
>> * @dev: struct device of the phy provider
>> + * @children: device node containing children (if different from dev->of_node)
>> * @owner: the module owner containing of_xlate
>> * @of_xlate: function pointer to obtain phy instance from phy provider
>> *
>> * Creates struct phy_provider from dev and of_xlate function pointer.
>> * This is used in the case of dt boot for finding the phy instance from
>> * phy provider.
>> + *
>> + * If the PHY provider doesn't nest children directly but uses a separate
>> + * child node to contain the individual children, the @children parameter
>> + * can be used to override the default (i.e. dev->of_node).
>> */
>> struct phy_provider *__of_phy_provider_register(struct device *dev,
>> - struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>> - struct of_phandle_args *args))
>> + struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args))
>> {
>> struct phy_provider *phy_provider;
>>
>> @@ -829,6 +841,7 @@ struct phy_provider *__of_phy_provider_register(struct device *dev,
>> return ERR_PTR(-ENOMEM);
>>
>> phy_provider->dev = dev;
>> + phy_provider->children = children;

I think we should atleast make sure that *children* is actually a subnode of
*dev* whatever level it might be?

Thanks
Kishon

>> phy_provider->owner = owner;
>> phy_provider->of_xlate = of_xlate;
>>
>> @@ -854,8 +867,9 @@ EXPORT_SYMBOL_GPL(__of_phy_provider_register);
>> * on the devres data, then, devres data is freed.
>> */
>> struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
>> - struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>> - struct of_phandle_args *args))
>> + struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args))
>> {
>> struct phy_provider **ptr, *phy_provider;
>>
>> @@ -863,7 +877,8 @@ struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
>> if (!ptr)
>> return ERR_PTR(-ENOMEM);
>>
>> - phy_provider = __of_phy_provider_register(dev, owner, of_xlate);
>> + phy_provider = __of_phy_provider_register(dev, children, owner,
>> + of_xlate);
>> if (!IS_ERR(phy_provider)) {
>> *ptr = phy_provider;
>> devres_add(dev, ptr);
>> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
>> index 8cf05e341cff..a810f2a18842 100644
>> --- a/include/linux/phy/phy.h
>> +++ b/include/linux/phy/phy.h
>> @@ -77,6 +77,7 @@ struct phy {
>> */
>> struct phy_provider {
>> struct device *dev;
>> + struct device_node *children;
>> struct module *owner;
>> struct list_head list;
>> struct phy * (*of_xlate)(struct device *dev,
>> @@ -93,10 +94,16 @@ struct phy_lookup {
>> #define to_phy(a) (container_of((a), struct phy, dev))
>>
>> #define of_phy_provider_register(dev, xlate) \
>> - __of_phy_provider_register((dev), THIS_MODULE, (xlate))
>> + __of_phy_provider_register((dev), NULL, THIS_MODULE, (xlate))
>>
>> #define devm_of_phy_provider_register(dev, xlate) \
>> - __devm_of_phy_provider_register((dev), THIS_MODULE, (xlate))
>> + __devm_of_phy_provider_register((dev), NULL, THIS_MODULE, (xlate))
>> +
>> +#define of_phy_provider_register_full(dev, children, xlate) \
>> + __of_phy_provider_register(dev, children, THIS_MODULE, xlate)
>> +
>> +#define devm_of_phy_provider_register_full(dev, children, xlate) \
>> + __devm_of_phy_provider_register(dev, children, THIS_MODULE, xlate)
>>
>> static inline void phy_set_drvdata(struct phy *phy, void *data)
>> {
>> @@ -147,11 +154,13 @@ struct phy *devm_phy_create(struct device *dev, struct device_node *node,
>> void phy_destroy(struct phy *phy);
>> void devm_phy_destroy(struct device *dev, struct phy *phy);
>> struct phy_provider *__of_phy_provider_register(struct device *dev,
>> - struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>> - struct of_phandle_args *args));
>> + struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args));
>> struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
>> - struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>> - struct of_phandle_args *args));
>> + struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args));
>> void of_phy_provider_unregister(struct phy_provider *phy_provider);
>> void devm_of_phy_provider_unregister(struct device *dev,
>> struct phy_provider *phy_provider);
>> @@ -312,15 +321,17 @@ static inline void devm_phy_destroy(struct device *dev, struct phy *phy)
>> }
>>
>> static inline struct phy_provider *__of_phy_provider_register(
>> - struct device *dev, struct module *owner, struct phy * (*of_xlate)(
>> - struct device *dev, struct of_phandle_args *args))
>> + struct device *dev, struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args))
>> {
>> return ERR_PTR(-ENOSYS);
>> }
>>
>> static inline struct phy_provider *__devm_of_phy_provider_register(struct device
>> - *dev, struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>> - struct of_phandle_args *args))
>> + *dev, struct device_node *children, struct module *owner,
>> + struct phy * (*of_xlate)(struct device *dev,
>> + struct of_phandle_args *args))
>> {
>> return ERR_PTR(-ENOSYS);
>> }
>> --
>> 2.8.0
>>
>
>