Messages in this thread |  | | Date | Mon, 21 Jan 2013 19:04:45 +0530 | From | kishon <> | Subject | Re: [RFC PATCH 5/6] usb: otg: add device tree support to otg library |
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On Monday 21 January 2013 06:51 PM, Roger Quadros wrote: > 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.
Thats how we create a "managed device resource". You can have a look at Documentation/driver-model/devres.txt and drivers/base/devres.c.
I'm not sure if that is what you are looking for :-P
Thanks Kishon
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