From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <50FD4F61.6060702@ti.com> Date: Mon, 21 Jan 2013 16:23:29 +0200 From: Roger Quadros MIME-Version: 1.0 To: kishon Subject: Re: [RFC PATCH 5/6] usb: otg: add device tree support to otg library References: <1358348462-27693-1-git-send-email-kishon@ti.com> <1358348462-27693-6-git-send-email-kishon@ti.com> <50FD40D1.8020405@ti.com> <50FD43F5.1020208@ti.com> In-Reply-To: <50FD43F5.1020208@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Cc: linux-doc@vger.kernel.org, tony@atomide.com, linux@arm.linux.org.uk, linux-sh@vger.kernel.org, alexander.shishkin@linux.intel.com, stern@rowland.harvard.edu, devicetree-discuss@lists.ozlabs.org, linuxppc-dev@lists.ozlabs.org, rob.herring@calxeda.com, horms@verge.net.au, Marc Kleine-Budde , haojian.zhuang@gmail.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, eric.y.miao@gmail.com, b-cousson@ti.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, balbi@ti.com, cbou@mail.ru, rob@landley.net, dwmw2@infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/21/2013 03:34 PM, kishon wrote: > 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 >>> Signed-off-by: Kishon Vijay Abraham I >>> --- >>> 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 >>> #include >>> #include >>> +#include >>> #include >>> +#include >>> >>> #include >>> >>> @@ -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