diff mbox

[v1,2/6] usb: otg: utils: add facilities in phy lib to support multiple PHYs of same type

Message ID 1358848694-20145-3-git-send-email-kishon@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kishon Vijay Abraham I Jan. 22, 2013, 9:58 a.m. UTC
In order to add support for multipe PHY's of the same type, new API's
for adding PHY and getting PHY has been added. Now the binding
information for the PHY and controller should be done in platform file
using usb_bind_phy API. And for getting a PHY, the device pointer of the
USB controller and an index should be passed. Based on the binding
information that is added in the platform file, usb_get_phy_dev will return the
appropriate PHY.
Already existing API's to add and get phy by type is not removed. These
API's are deprecated and will be removed once all the platforms start to
use the new API.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/usb/otg/otg.c   |  114 ++++++++++++++++++++++++++++++++++++++++++++++-
 include/linux/usb/phy.h |   13 ++++++
 2 files changed, 126 insertions(+), 1 deletion(-)

Comments

Roger Quadros Jan. 22, 2013, 2:07 p.m. UTC | #1
On 01/22/2013 11:58 AM, Kishon Vijay Abraham I wrote:
> In order to add support for multipe PHY's of the same type, new API's
> for adding PHY and getting PHY has been added. Now the binding
> information for the PHY and controller should be done in platform file
> using usb_bind_phy API. And for getting a PHY, the device pointer of the
> USB controller and an index should be passed. Based on the binding
> information that is added in the platform file, usb_get_phy_dev will return the
> appropriate PHY.
> Already existing API's to add and get phy by type is not removed. These
> API's are deprecated and will be removed once all the platforms start to
> use the new API.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  drivers/usb/otg/otg.c   |  114 ++++++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/usb/phy.h |   13 ++++++
>  2 files changed, 126 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
> index 492ba2f..1f30b22 100644
> --- a/drivers/usb/otg/otg.c
> +++ b/drivers/usb/otg/otg.c
> @@ -36,6 +36,20 @@ static struct usb_phy *__usb_find_phy(struct list_head *list,
>  	return ERR_PTR(-ENODEV);
>  }
>  
> +static struct usb_phy *__usb_find_phy_dev(struct device *dev,
> +	struct list_head *list, u8 index)
> +{
> +	struct usb_phy_bind *phy_bind = NULL;
> +
> +	list_for_each_entry(phy_bind, list, list) {
> +		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
> +				phy_bind->index == index)
> +			return phy_bind->phy;

If the PHY driver has not yet called usb_add_phy_dev() (e.g. driver not yet loaeded)
then this will return NULL.

> +	}
> +
> +	return ERR_PTR(-ENODEV);
> +}
> +
>  static void devm_usb_phy_release(struct device *dev, void *res)
>  {
>  	struct usb_phy *phy = *(struct usb_phy **)res;
> @@ -112,6 +126,69 @@ err0:
>  EXPORT_SYMBOL(usb_get_phy);
>  
>  /**
> + * usb_get_phy_dev - find the USB PHY
> + * @dev - device that requests this phy
> + * @index - the index of the phy
> + *
> + * Returns the phy driver, after getting a refcount to it; or
> + * -ENODEV if there is no such phy.  The caller is responsible for
> + * calling usb_put_phy() to release that count.
> + *
> + * For use by USB host and peripheral drivers.
> + */
> +struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
> +{
> +	struct usb_phy	*phy = NULL;
> +	unsigned long	flags;
> +
> +	spin_lock_irqsave(&phy_lock, flags);
> +
> +	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
> +	if (IS_ERR(phy)) {
> +		pr_err("unable to find transceiver\n");
> +		goto err0;
> +	}

Since NULL is not IS_ERR(), you will do a NULL pointer reference below.

In such cases we would want to use the deferred probe mechanism. So should we return
-EPROBE_DEFER?

> +
> +	get_device(phy->dev);
> +
> +err0:
> +	spin_unlock_irqrestore(&phy_lock, flags);
> +
> +	return phy;
> +}
> +EXPORT_SYMBOL(usb_get_phy_dev);
> +

--
cheers,
-roger
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Kishon Vijay Abraham I Jan. 22, 2013, 2:13 p.m. UTC | #2
Hi,

On Tuesday 22 January 2013 07:37 PM, Roger Quadros wrote:
> On 01/22/2013 11:58 AM, Kishon Vijay Abraham I wrote:
>> In order to add support for multipe PHY's of the same type, new API's
>> for adding PHY and getting PHY has been added. Now the binding
>> information for the PHY and controller should be done in platform file
>> using usb_bind_phy API. And for getting a PHY, the device pointer of the
>> USB controller and an index should be passed. Based on the binding
>> information that is added in the platform file, usb_get_phy_dev will return the
>> appropriate PHY.
>> Already existing API's to add and get phy by type is not removed. These
>> API's are deprecated and will be removed once all the platforms start to
>> use the new API.
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>   drivers/usb/otg/otg.c   |  114 ++++++++++++++++++++++++++++++++++++++++++++++-
>>   include/linux/usb/phy.h |   13 ++++++
>>   2 files changed, 126 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
>> index 492ba2f..1f30b22 100644
>> --- a/drivers/usb/otg/otg.c
>> +++ b/drivers/usb/otg/otg.c
>> @@ -36,6 +36,20 @@ static struct usb_phy *__usb_find_phy(struct list_head *list,
>>   	return ERR_PTR(-ENODEV);
>>   }
>>
>> +static struct usb_phy *__usb_find_phy_dev(struct device *dev,
>> +	struct list_head *list, u8 index)
>> +{
>> +	struct usb_phy_bind *phy_bind = NULL;
>> +
>> +	list_for_each_entry(phy_bind, list, list) {
>> +		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
>> +				phy_bind->index == index)
>> +			return phy_bind->phy;
>
> If the PHY driver has not yet called usb_add_phy_dev() (e.g. driver not yet loaeded)
> then this will return NULL.
>
>> +	}
>> +
>> +	return ERR_PTR(-ENODEV);
>> +}
>> +
>>   static void devm_usb_phy_release(struct device *dev, void *res)
>>   {
>>   	struct usb_phy *phy = *(struct usb_phy **)res;
>> @@ -112,6 +126,69 @@ err0:
>>   EXPORT_SYMBOL(usb_get_phy);
>>
>>   /**
>> + * usb_get_phy_dev - find the USB PHY
>> + * @dev - device that requests this phy
>> + * @index - the index of the phy
>> + *
>> + * Returns the phy driver, after getting a refcount to it; or
>> + * -ENODEV if there is no such phy.  The caller is responsible for
>> + * calling usb_put_phy() to release that count.
>> + *
>> + * For use by USB host and peripheral drivers.
>> + */
>> +struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
>> +{
>> +	struct usb_phy	*phy = NULL;
>> +	unsigned long	flags;
>> +
>> +	spin_lock_irqsave(&phy_lock, flags);
>> +
>> +	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
>> +	if (IS_ERR(phy)) {
>> +		pr_err("unable to find transceiver\n");
>> +		goto err0;
>> +	}
>
> Since NULL is not IS_ERR(), you will do a NULL pointer reference below.
>
> In such cases we would want to use the deferred probe mechanism. So should we return
> -EPROBE_DEFER?

Good catch. I'll update the patch.

Thanks
Kishon
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diff mbox

Patch

diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
index 492ba2f..1f30b22 100644
--- a/drivers/usb/otg/otg.c
+++ b/drivers/usb/otg/otg.c
@@ -36,6 +36,20 @@  static struct usb_phy *__usb_find_phy(struct list_head *list,
 	return ERR_PTR(-ENODEV);
 }
 
+static struct usb_phy *__usb_find_phy_dev(struct device *dev,
+	struct list_head *list, u8 index)
+{
+	struct usb_phy_bind *phy_bind = NULL;
+
+	list_for_each_entry(phy_bind, list, list) {
+		if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
+				phy_bind->index == index)
+			return phy_bind->phy;
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
 static void devm_usb_phy_release(struct device *dev, void *res)
 {
 	struct usb_phy *phy = *(struct usb_phy **)res;
@@ -112,6 +126,69 @@  err0:
 EXPORT_SYMBOL(usb_get_phy);
 
 /**
+ * usb_get_phy_dev - find the USB PHY
+ * @dev - device that requests this phy
+ * @index - the index of the phy
+ *
+ * Returns the phy driver, after getting a refcount to it; or
+ * -ENODEV if there is no such phy.  The caller is responsible for
+ * calling usb_put_phy() to release that count.
+ *
+ * For use by USB host and peripheral drivers.
+ */
+struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
+{
+	struct usb_phy	*phy = NULL;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&phy_lock, flags);
+
+	phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
+	if (IS_ERR(phy)) {
+		pr_err("unable to find transceiver\n");
+		goto err0;
+	}
+
+	get_device(phy->dev);
+
+err0:
+	spin_unlock_irqrestore(&phy_lock, flags);
+
+	return phy;
+}
+EXPORT_SYMBOL(usb_get_phy_dev);
+
+/**
+ * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
+ * @dev - device that requests this phy
+ * @index - the index of the phy
+ *
+ * Gets the phy using usb_get_phy_dev(), and associates a device with it using
+ * devres. On driver detach, release function is invoked on the devres data,
+ * then, devres data is freed.
+ *
+ * For use by USB host and peripheral drivers.
+ */
+struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
+{
+	struct usb_phy **ptr, *phy;
+
+	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return NULL;
+
+	phy = usb_get_phy_dev(dev, index);
+	if (!IS_ERR(phy)) {
+		*ptr = phy;
+		devres_add(dev, ptr);
+	} else
+		devres_free(ptr);
+
+	return phy;
+}
+EXPORT_SYMBOL(devm_usb_get_phy_dev);
+
+/**
  * devm_usb_put_phy - release the USB PHY
  * @dev - device that wants to release this phy
  * @phy - the phy returned by devm_usb_get_phy()
@@ -186,6 +263,36 @@  out:
 EXPORT_SYMBOL(usb_add_phy);
 
 /**
+ * usb_add_phy_dev - declare the USB PHY
+ * @x: the USB phy to be used; or NULL
+ *
+ * This call is exclusively for use by phy drivers, which
+ * coordinate the activities of drivers for host and peripheral
+ * controllers, and in some cases for VBUS current regulation.
+ */
+int usb_add_phy_dev(struct usb_phy *x)
+{
+	struct usb_phy_bind *phy_bind;
+	unsigned long flags;
+
+	if (!x->dev) {
+		dev_err(x->dev, "no device provided for PHY\n");
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&phy_lock, flags);
+	list_for_each_entry(phy_bind, &phy_bind_list, list)
+		if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
+			phy_bind->phy = x;
+
+	list_add_tail(&x->head, &phy_list);
+
+	spin_unlock_irqrestore(&phy_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(usb_add_phy_dev);
+
+/**
  * usb_remove_phy - remove the OTG PHY
  * @x: the USB OTG PHY to be removed;
  *
@@ -194,10 +301,15 @@  EXPORT_SYMBOL(usb_add_phy);
 void usb_remove_phy(struct usb_phy *x)
 {
 	unsigned long	flags;
+	struct usb_phy_bind *phy_bind;
 
 	spin_lock_irqsave(&phy_lock, flags);
-	if (x)
+	if (x) {
+		list_for_each_entry(phy_bind, &phy_bind_list, list)
+			if (phy_bind->phy == x)
+				phy_bind->phy = NULL;
 		list_del(&x->head);
+	}
 	spin_unlock_irqrestore(&phy_lock, flags);
 }
 EXPORT_SYMBOL(usb_remove_phy);
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index fbeab1a..3a9ae3e 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -124,6 +124,7 @@  struct usb_phy_bind {
 
 /* for board-specific init logic */
 extern int usb_add_phy(struct usb_phy *, enum usb_phy_type type);
+extern int usb_add_phy_dev(struct usb_phy *);
 extern void usb_remove_phy(struct usb_phy *);
 
 /* helpers for direct access thru low-level io interface */
@@ -164,6 +165,8 @@  usb_phy_shutdown(struct usb_phy *x)
 extern struct usb_phy *usb_get_phy(enum usb_phy_type type);
 extern struct usb_phy *devm_usb_get_phy(struct device *dev,
 	enum usb_phy_type type);
+extern struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index);
+extern struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index);
 extern void usb_put_phy(struct usb_phy *);
 extern void devm_usb_put_phy(struct device *dev, struct usb_phy *x);
 extern struct usb_phy_bind *usb_bind_phy(const char *dev_name, u8 index,
@@ -180,6 +183,16 @@  static inline struct usb_phy *devm_usb_get_phy(struct device *dev,
 	return NULL;
 }
 
+static inline struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
+{
+	return NULL;
+}
+
+static inline struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
+{
+	return NULL;
+}
+
 static inline void usb_put_phy(struct usb_phy *x)
 {
 }