diff mbox

[v1,5/6] usb: otg: add device tree support to otg library

Message ID 1358848694-20145-6-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 
Added an API devm_usb_get_phy_by_phandle(), to get usb phy by passing a
device node phandle value. This function will return a pointer to
the phy on success, -EPROBE_DEFER if there is a device_node for the phandle,
but the phy has not been added, or a ERR_PTR() otherwise.

Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/usb/otg/otg.c   |   77 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/phy.h |    8 +++++
 2 files changed, 85 insertions(+)

Comments

Mark Rutland Jan. 22, 2013, 10:36 a.m. UTC | #1 
> +struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
> +	const char *phandle, u8 index)
> +{
> +	struct usb_phy	*phy = NULL, **ptr;
> +	unsigned long	flags;
> +	struct device_node *node;
> +
> +	if (!dev->of_node) {
> +		dev_dbg(dev, "device does not have a device node entry\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	node = of_parse_phandle(dev->of_node, phandle, index);
> +	if (!node) {
> +		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
> +			dev->of_node->full_name);
> +		return ERR_PTR(-ENODEV);
> +	}

At any point past this, node's refcount is incremented (done automatically by
of_parse_phandle => of_find_node_by_phandle).

> +
> +	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr) {
> +		dev_dbg(dev, "failed to allocate memory for devres\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	spin_lock_irqsave(&phy_lock, flags);
> +
> +	phy = __of_usb_find_phy(node);
> +	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
> +		phy = ERR_PTR(-EPROBE_DEFER);
> +		devres_free(ptr);
> +		goto err0;
> +	}
> +
> +	*ptr = phy;
> +	devres_add(dev, ptr);
> +
> +	get_device(phy->dev);
> +
> +err0:
> +	spin_unlock_irqrestore(&phy_lock, flags);
> +
> +	return phy;
> +}

This means that on all of the exit paths, node's refcount is left incremented
incorrectly. You'll need an of_node_put(node) on each exit path.

Thanks,
Mark.
Kishon Vijay Abraham I Jan. 22, 2013, 3:37 p.m. UTC | #2 
Hi,

On Tuesday 22 January 2013 04:06 PM, Mark Rutland wrote:
>> +struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
>> +	const char *phandle, u8 index)
>> +{
>> +	struct usb_phy	*phy = NULL, **ptr;
>> +	unsigned long	flags;
>> +	struct device_node *node;
>> +
>> +	if (!dev->of_node) {
>> +		dev_dbg(dev, "device does not have a device node entry\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>> +	node = of_parse_phandle(dev->of_node, phandle, index);
>> +	if (!node) {
>> +		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
>> +			dev->of_node->full_name);
>> +		return ERR_PTR(-ENODEV);
>> +	}
>
> At any point past this, node's refcount is incremented (done automatically by
> of_parse_phandle => of_find_node_by_phandle).
>
>> +
>> +	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
>> +	if (!ptr) {
>> +		dev_dbg(dev, "failed to allocate memory for devres\n");
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	spin_lock_irqsave(&phy_lock, flags);
>> +
>> +	phy = __of_usb_find_phy(node);
>> +	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
>> +		phy = ERR_PTR(-EPROBE_DEFER);
>> +		devres_free(ptr);
>> +		goto err0;
>> +	}
>> +
>> +	*ptr = phy;
>> +	devres_add(dev, ptr);
>> +
>> +	get_device(phy->dev);
>> +
>> +err0:
>> +	spin_unlock_irqrestore(&phy_lock, flags);
>> +
>> +	return phy;
>> +}
>
> This means that on all of the exit paths, node's refcount is left incremented
> incorrectly. You'll need an of_node_put(node) on each exit path.

Ok. Will fix it.

Thanks
Kishon
diff mbox

Patch

diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
index 1f30b22..67daf8c 100644
--- a/drivers/usb/otg/otg.c
+++ b/drivers/usb/otg/otg.c
@@ -13,7 +13,9 @@ 
 #include <linux/export.h>
 #include <linux/err.h>
 #include <linux/device.h>
+#include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #include <linux/usb/otg.h>
 
@@ -50,6 +52,20 @@  static struct usb_phy *__usb_find_phy_dev(struct device *dev,
 	return ERR_PTR(-ENODEV);
 }
 
+static struct usb_phy *__of_usb_find_phy(struct device_node *node)
+{
+	struct usb_phy  *phy;
+
+	list_for_each_entry(phy, &phy_list, head) {
+		if (node != phy->dev->of_node)
+			continue;
+
+		return phy;
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
 static void devm_usb_phy_release(struct device *dev, void *res)
 {
 	struct usb_phy *phy = *(struct usb_phy **)res;
@@ -125,6 +141,67 @@  err0:
 }
 EXPORT_SYMBOL(usb_get_phy);
 
+ /**
+ * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
+ * @dev - device that requests this phy
+ * @phandle - name of the property holding the phy phandle value
+ * @index - the index of the phy
+ *
+ * Returns the phy driver associated with the given phandle value,
+ * after getting a refcount to it, -ENODEV if there is no such phy or
+ * -EPROBE_DEFER if there is a phandle to the phy, but the device is
+ * not yet loaded. While at that, it also associates the device with
+ * the phy 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_by_phandle(struct device *dev,
+	const char *phandle, u8 index)
+{
+	struct usb_phy	*phy = NULL, **ptr;
+	unsigned long	flags;
+	struct device_node *node;
+
+	if (!dev->of_node) {
+		dev_dbg(dev, "device does not have a device node entry\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	node = of_parse_phandle(dev->of_node, phandle, index);
+	if (!node) {
+		dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
+			dev->of_node->full_name);
+		return ERR_PTR(-ENODEV);
+	}
+
+	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr) {
+		dev_dbg(dev, "failed to allocate memory for devres\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	spin_lock_irqsave(&phy_lock, flags);
+
+	phy = __of_usb_find_phy(node);
+	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
+		phy = ERR_PTR(-EPROBE_DEFER);
+		devres_free(ptr);
+		goto err0;
+	}
+
+	*ptr = phy;
+	devres_add(dev, ptr);
+
+	get_device(phy->dev);
+
+err0:
+	spin_unlock_irqrestore(&phy_lock, flags);
+
+	return phy;
+}
+EXPORT_SYMBOL(devm_usb_get_phy_by_phandle);
+
 /**
  * usb_get_phy_dev - find the USB PHY
  * @dev - device that requests this phy
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 3a9ae3e..c7f5a98 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -167,6 +167,8 @@  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 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
+	const char *phandle, 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,
@@ -193,6 +195,12 @@  static inline struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
 	return NULL;
 }
 
+static inline struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
+	const char *phandle, u8 index)
+{
+	return NULL;
+}
+
 static inline void usb_put_phy(struct usb_phy *x)
 {
 }