From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Tull Subject: Re: [PATCH v4 06/24] fpga: dfl: adds fpga_cdev_find_port Date: Wed, 14 Feb 2018 10:24:47 -0600 Message-ID: References: <1518513893-4719-1-git-send-email-hao.wu@intel.com> <1518513893-4719-7-git-send-email-hao.wu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1518513893-4719-7-git-send-email-hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wu Hao Cc: Moritz Fischer , linux-fpga-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Kang, Luwei" , "Zhang, Yi Z" , Tim Whisonant , Enno Luebbers , Shiva Rao , Christopher Rauer , Xiao Guangrong List-Id: linux-api@vger.kernel.org On Tue, Feb 13, 2018 at 3:24 AM, Wu Hao wrote: Hi Hao, > For feature devices, we need a method to find the port dedicated > to the device. This patch adds a function fpga_cdev_find_port > for this purpose. e.g FPGA Management Engine (FME) Partial > Reconfiguration sub feature, it uses this function to find > dedicated port on the device for PR function implementation. OK, that is very clear now, thanks! Ack with the minor doc changes below. > > Signed-off-by: Tim Whisonant > Signed-off-by: Enno Luebbers > Signed-off-by: Shiva Rao > Signed-off-by: Christopher Rauer > Signed-off-by: Xiao Guangrong > Signed-off-by: Wu Hao Acked-by: Alan Tull > --- > v3: s/fpga_for_each_port/fpga_cdev_find_port/ > move fpga_cdev_find_port to fpga-dfl module. > v4: improve description in commit message. > add comments to remind user to put_device after use this function. > --- > drivers/fpga/dfl.c | 34 ++++++++++++++++++++++++++++++++++ > drivers/fpga/dfl.h | 20 ++++++++++++++++++++ > 2 files changed, 54 insertions(+) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index dcfe5ab..38dc819 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -783,6 +783,40 @@ void fpga_remove_feature_devs(struct fpga_cdev *cdev) > } > EXPORT_SYMBOL_GPL(fpga_remove_feature_devs); > > +/** > + * __fpga_cdev_find_port - find a port under given container device > + * > + * @cdev: container device > + * @data: data passed to match function > + * @match: match function used to find specific port from the port device list > + * > + * Find a port device under container device. This function needs to be > + * invoked with lock held. > + * > + * This function returns NULL if the device doesn't match and non-zero if it > + * does. Good but this would be more brief and more specific and more in line with recommended format in Documentation/kernel-doc-nano-HOWTO.txt: * Return: pointer to port's platform device if successful, NULL otherwise. > If this function returns non-zero and a reference to the platform > + * device of port can be obtained. This if..then type sentence is not complete (missing the 'then' part). I see where you might have gotten inspiration for it from core.c. Probably you could just delete the sentence and all would be clear. > + * > + * NOTE: you will need to drop the device reference with put_device() after use. > + */ Good Thanks, Alan > +struct platform_device * > +__fpga_cdev_find_port(struct fpga_cdev *cdev, void *data, > + int (*match)(struct platform_device *, void *)) > +{ > + struct feature_platform_data *pdata; > + struct platform_device *port_dev; > + > + list_for_each_entry(pdata, &cdev->port_dev_list, node) { > + port_dev = pdata->dev; > + > + if (match(port_dev, data) && get_device(&port_dev->dev)) > + return port_dev; > + } > + > + return NULL; > +} > +EXPORT_SYMBOL_GPL(__fpga_cdev_find_port); > + > int fpga_port_id(struct platform_device *pdev) > { > void __iomem *base = get_feature_ioaddr_by_id(&pdev->dev, > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h > index 9b19399..d6ecda1 100644 > --- a/drivers/fpga/dfl.h > +++ b/drivers/fpga/dfl.h > @@ -356,4 +356,24 @@ struct fpga_cdev { > struct fpga_cdev *fpga_enumerate_feature_devs(struct fpga_enum_info *info); > void fpga_remove_feature_devs(struct fpga_cdev *cdev); > > +/* > + * need to drop the device reference with put_device() after use port platform > + * device returned by __fpga_cdev_find_port and fpga_cdev_find_port functions. > + */ > +struct platform_device * > +__fpga_cdev_find_port(struct fpga_cdev *cdev, void *data, > + int (*match)(struct platform_device *, void *)); > + > +static inline struct platform_device * > +fpga_cdev_find_port(struct fpga_cdev *cdev, void *data, > + int (*match)(struct platform_device *, void *)) > +{ > + struct platform_device *pdev; > + > + mutex_lock(&cdev->lock); > + pdev = __fpga_cdev_find_port(cdev, data, match); > + mutex_unlock(&cdev->lock); > + > + return pdev; > +} > #endif /* __FPGA_DFL_H */ > -- > 2.7.4 >