Re: [PATCH v4 06/24] fpga: dfl: adds fpga_cdev_find_port
From: Alan Tull <hidden>
Date: 2018-02-14 16:25:31
Also in:
linux-fpga, lkml
On Tue, Feb 13, 2018 at 3:24 AM, Wu Hao [off-list ref] 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 <redacted> Signed-off-by: Enno Luebbers <redacted> Signed-off-by: Shiva Rao <redacted> Signed-off-by: Christopher Rauer <redacted> Signed-off-by: Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Signed-off-by: Wu Hao <redacted>
Acked-by: Alan Tull <redacted>
quoted hunk ↗ jump to hunk
--- 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
quoted hunk ↗ jump to hunk
+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