lkml.org 
[lkml]   [2013]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC PATCH 5/6] usb: otg: add device tree support to otg library
    On 01/16/2013 05:01 PM, Kishon Vijay Abraham I wrote:
    > 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(+)
    >
    > 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.

    > +
    > + 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);
    > +

    --
    cheers,
    -roger



    \
     
     \ /
      Last update: 2013-01-21 15:01    [W:4.329 / U:0.724 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site