On 01/21/2013 03:34 PM, kishon wrote:

On Monday 21 January 2013 06:51 PM, Roger Quadros wrote:

quoted

On 01/16/2013 05:01 PM, Kishon Vijay Abraham I wrote:

quoted

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 <redacted>
---
  drivers/usb/otg/otg.c   |   77
+++++++++++++++++++++++++++++++++++++++++++++++
  include/linux/usb/phy.h |    8 +++++
  2 files changed, 85 insertions(+)

diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
index dbf2043..e9799bb 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>

@@ -34,6 +36,20 @@ static struct usb_phy *__usb_find_phy(struct

device *dev, u8 index)
      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;

@@ -109,6 +125,67 @@ 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);
+    }

I fail to understand why you need ptr at all and why do devres_alloc()
for it.

Thats how we create a "managed device resource". You can have a look at
Documentation/driver-model/devres.txt and drivers/base/devres.c.

OK, I get it now. You might want to update the text file too since you
are adding a automagically managed interface.

regards,
-roger