Implement a platform driver that matches with xlnx,
sd-fec-1.1 device tree node and registers as a character
device, including:
- SD-FEC driver binds to sdfec DT node.
- creates and initialise an initial driver dev structure.
- add the driver in Linux build and Kconfig.
Tested-by: Dragan Cvetic <[email protected]>
Signed-off-by: Derek Kiernan <[email protected]>
Signed-off-by: Dragan Cvetic <[email protected]>
---
drivers/misc/Kconfig | 12 +++++
drivers/misc/Makefile | 1 +
drivers/misc/xilinx_sdfec.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 131 insertions(+)
create mode 100644 drivers/misc/xilinx_sdfec.c
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 6b0417b..319a6bf 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -471,6 +471,18 @@ config PCI_ENDPOINT_TEST
Enable this configuration option to enable the host side test driver
for PCI Endpoint.
+config XILINX_SDFEC
+ tristate "Xilinx SDFEC 16"
+ help
+ This option enables support for the Xilinx SDFEC (Soft Decision
+ Forward Error Correction) driver. This enables a char driver
+ for the SDFEC.
+
+ You may select this driver if your design instantiates the
+ SDFEC(16nm) hardened block. To compile this as a module choose M.
+
+ If unsure, say N.
+
config MISC_RTSX
tristate
default MISC_RTSX_PCI || MISC_RTSX_USB
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index b9affcd..0cb3546 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -59,3 +59,4 @@ obj-$(CONFIG_OCXL) += ocxl/
obj-y += cardreader/
obj-$(CONFIG_PVPANIC) += pvpanic.o
obj-$(CONFIG_HABANA_AI) += habanalabs/
+obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
new file mode 100644
index 0000000..75cc980
--- /dev/null
+++ b/drivers/misc/xilinx_sdfec.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx SDFEC
+ *
+ * Copyright (C) 2019 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
+ * IP. It exposes a char device which supports file operations
+ * like open(), close() and ioctl().
+ */
+
+#include <linux/miscdevice.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+
+static int xsdfec_ndevs;
+
+/**
+ * struct xsdfec_dev - Driver data for SDFEC
+ * @regs: device physical base address
+ * @dev: pointer to device struct
+ * @miscdev: Misc device handle
+ * @error_data_lock: Error counter and states spinlock
+ *
+ * This structure contains necessary state for SDFEC driver to operate
+ */
+struct xsdfec_dev {
+ void __iomem *regs;
+ struct device *dev;
+ struct miscdevice miscdev;
+ /* Spinlock to protect state_updated and stats_updated */
+ spinlock_t error_data_lock;
+};
+
+static const struct file_operations xsdfec_fops = {
+ .owner = THIS_MODULE,
+};
+
+static int xsdfec_probe(struct platform_device *pdev)
+{
+ struct xsdfec_dev *xsdfec;
+ struct device *dev;
+ struct resource *res;
+ int err;
+ char buf[16];
+
+ xsdfec = devm_kzalloc(&pdev->dev, sizeof(*xsdfec), GFP_KERNEL);
+ if (!xsdfec)
+ return -ENOMEM;
+
+ xsdfec->dev = &pdev->dev;
+ spin_lock_init(&xsdfec->error_data_lock);
+
+ dev = xsdfec->dev;
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ xsdfec->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(xsdfec->regs)) {
+ err = PTR_ERR(xsdfec->regs);
+ return err;
+ }
+
+ /* Save driver private data */
+ platform_set_drvdata(pdev, xsdfec);
+
+ snprintf(buf, 16, "xsdfec%d", xsdfec_ndevs);
+ xsdfec->miscdev.minor = MISC_DYNAMIC_MINOR;
+ xsdfec->miscdev.name = buf;
+ xsdfec->miscdev.fops = &xsdfec_fops;
+ xsdfec->miscdev.parent = dev;
+ err = misc_register(&xsdfec->miscdev);
+ if (err) {
+ dev_err(dev, "error:%d. Unable to register device", err);
+ return err;
+ }
+
+ xsdfec_ndevs += 1;
+ return 0;
+}
+
+static int xsdfec_remove(struct platform_device *pdev)
+{
+ struct xsdfec_dev *xsdfec;
+
+ xsdfec = platform_get_drvdata(pdev);
+ misc_deregister(&xsdfec->miscdev);
+ xsdfec_ndevs -= 1;
+ return 0;
+}
+
+static const struct of_device_id xsdfec_of_match[] = {
+ {
+ .compatible = "xlnx,sd-fec-1.1",
+ },
+ { /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, xsdfec_of_match);
+
+static struct platform_driver xsdfec_driver = {
+ .driver = {
+ .name = "xilinx-sdfec",
+ .of_match_table = xsdfec_of_match,
+ },
+ .probe = xsdfec_probe,
+ .remove = xsdfec_remove,
+};
+
+module_platform_driver(xsdfec_driver);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("Xilinx SD-FEC16 Driver");
+MODULE_LICENSE("GPL");
--
2.7.4
On Sun, Jun 09, 2019 at 01:04:07AM +0100, Dragan Cvetic wrote:
> Implement a platform driver that matches with xlnx,
> sd-fec-1.1 device tree node and registers as a character
> device, including:
> - SD-FEC driver binds to sdfec DT node.
> - creates and initialise an initial driver dev structure.
> - add the driver in Linux build and Kconfig.
>
> Tested-by: Dragan Cvetic <[email protected]>
> Signed-off-by: Derek Kiernan <[email protected]>
> Signed-off-by: Dragan Cvetic <[email protected]>
> ---
> drivers/misc/Kconfig | 12 +++++
> drivers/misc/Makefile | 1 +
> drivers/misc/xilinx_sdfec.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 131 insertions(+)
> create mode 100644 drivers/misc/xilinx_sdfec.c
>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 6b0417b..319a6bf 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -471,6 +471,18 @@ config PCI_ENDPOINT_TEST
> Enable this configuration option to enable the host side test driver
> for PCI Endpoint.
>
> +config XILINX_SDFEC
> + tristate "Xilinx SDFEC 16"
> + help
> + This option enables support for the Xilinx SDFEC (Soft Decision
> + Forward Error Correction) driver. This enables a char driver
> + for the SDFEC.
> +
> + You may select this driver if your design instantiates the
> + SDFEC(16nm) hardened block. To compile this as a module choose M.
> +
> + If unsure, say N.
> +
> config MISC_RTSX
> tristate
> default MISC_RTSX_PCI || MISC_RTSX_USB
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index b9affcd..0cb3546 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -59,3 +59,4 @@ obj-$(CONFIG_OCXL) += ocxl/
> obj-y += cardreader/
> obj-$(CONFIG_PVPANIC) += pvpanic.o
> obj-$(CONFIG_HABANA_AI) += habanalabs/
> +obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
> diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
> new file mode 100644
> index 0000000..75cc980
> --- /dev/null
> +++ b/drivers/misc/xilinx_sdfec.c
> @@ -0,0 +1,118 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx SDFEC
> + *
> + * Copyright (C) 2019 Xilinx, Inc.
> + *
> + * Description:
> + * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
> + * IP. It exposes a char device which supports file operations
> + * like open(), close() and ioctl().
> + */
> +
> +#include <linux/miscdevice.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/poll.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +
> +static int xsdfec_ndevs;
You should use an idr for this, not just a number you bump up and down.
This will not work properly at all.
Think about this situation:
probe device 0
xsdfec_ndevs = 1
probe device 1
xsdfec_ndevs = 2
remove device 0
xsdfec_ndevs = 0
probe another device
misc device fails due to duplicate name.
thanks,
greg k-h
> -----Original Message-----
> From: Greg KH [mailto:[email protected]]
> Sent: Sunday 9 June 2019 12:23
> To: Dragan Cvetic <[email protected]>
> Cc: [email protected]; Michal Simek <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; Derek Kiernan <[email protected]>
> Subject: Re: [PATCH V5 02/11] misc: xilinx-sdfec: add core driver
>
> On Sun, Jun 09, 2019 at 01:04:07AM +0100, Dragan Cvetic wrote:
> > Implement a platform driver that matches with xlnx,
> > sd-fec-1.1 device tree node and registers as a character
> > device, including:
> > - SD-FEC driver binds to sdfec DT node.
> > - creates and initialise an initial driver dev structure.
> > - add the driver in Linux build and Kconfig.
> >
> > Tested-by: Dragan Cvetic <[email protected]>
> > Signed-off-by: Derek Kiernan <[email protected]>
> > Signed-off-by: Dragan Cvetic <[email protected]>
> > ---
> > drivers/misc/Kconfig | 12 +++++
> > drivers/misc/Makefile | 1 +
> > drivers/misc/xilinx_sdfec.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 131 insertions(+)
> > create mode 100644 drivers/misc/xilinx_sdfec.c
> >
> > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> > index 6b0417b..319a6bf 100644
> > --- a/drivers/misc/Kconfig
> > +++ b/drivers/misc/Kconfig
> > @@ -471,6 +471,18 @@ config PCI_ENDPOINT_TEST
> > Enable this configuration option to enable the host side test driver
> > for PCI Endpoint.
> >
> > +config XILINX_SDFEC
> > + tristate "Xilinx SDFEC 16"
> > + help
> > + This option enables support for the Xilinx SDFEC (Soft Decision
> > + Forward Error Correction) driver. This enables a char driver
> > + for the SDFEC.
> > +
> > + You may select this driver if your design instantiates the
> > + SDFEC(16nm) hardened block. To compile this as a module choose M.
> > +
> > + If unsure, say N.
> > +
> > config MISC_RTSX
> > tristate
> > default MISC_RTSX_PCI || MISC_RTSX_USB
> > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> > index b9affcd..0cb3546 100644
> > --- a/drivers/misc/Makefile
> > +++ b/drivers/misc/Makefile
> > @@ -59,3 +59,4 @@ obj-$(CONFIG_OCXL) += ocxl/
> > obj-y += cardreader/
> > obj-$(CONFIG_PVPANIC) += pvpanic.o
> > obj-$(CONFIG_HABANA_AI) += habanalabs/
> > +obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
> > diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
> > new file mode 100644
> > index 0000000..75cc980
> > --- /dev/null
> > +++ b/drivers/misc/xilinx_sdfec.c
> > @@ -0,0 +1,118 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Xilinx SDFEC
> > + *
> > + * Copyright (C) 2019 Xilinx, Inc.
> > + *
> > + * Description:
> > + * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
> > + * IP. It exposes a char device which supports file operations
> > + * like open(), close() and ioctl().
> > + */
> > +
> > +#include <linux/miscdevice.h>
> > +#include <linux/io.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/poll.h>
> > +#include <linux/slab.h>
> > +#include <linux/clk.h>
> > +
> > +static int xsdfec_ndevs;
>
> You should use an idr for this, not just a number you bump up and down.
> This will not work properly at all.
>
> Think about this situation:
> probe device 0
> xsdfec_ndevs = 1
> probe device 1
> xsdfec_ndevs = 2
> remove device 0
> xsdfec_ndevs = 0
> probe another device
> misc device fails due to duplicate name.
>
My bad.
I can use idr, but couldn't be better optimized code if use simple mutex to protect the variable.
> thanks,
>
> greg k-h
On Sun, Jun 09, 2019 at 06:48:31PM +0000, Dragan Cvetic wrote:
>
>
> > -----Original Message-----
> > From: Greg KH [mailto:[email protected]]
> > Sent: Sunday 9 June 2019 12:23
> > To: Dragan Cvetic <[email protected]>
> > Cc: [email protected]; Michal Simek <[email protected]>; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]; Derek Kiernan <[email protected]>
> > Subject: Re: [PATCH V5 02/11] misc: xilinx-sdfec: add core driver
> >
> > On Sun, Jun 09, 2019 at 01:04:07AM +0100, Dragan Cvetic wrote:
> > > Implement a platform driver that matches with xlnx,
> > > sd-fec-1.1 device tree node and registers as a character
> > > device, including:
> > > - SD-FEC driver binds to sdfec DT node.
> > > - creates and initialise an initial driver dev structure.
> > > - add the driver in Linux build and Kconfig.
> > >
> > > Tested-by: Dragan Cvetic <[email protected]>
> > > Signed-off-by: Derek Kiernan <[email protected]>
> > > Signed-off-by: Dragan Cvetic <[email protected]>
> > > ---
> > > drivers/misc/Kconfig | 12 +++++
> > > drivers/misc/Makefile | 1 +
> > > drivers/misc/xilinx_sdfec.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
> > > 3 files changed, 131 insertions(+)
> > > create mode 100644 drivers/misc/xilinx_sdfec.c
> > >
> > > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> > > index 6b0417b..319a6bf 100644
> > > --- a/drivers/misc/Kconfig
> > > +++ b/drivers/misc/Kconfig
> > > @@ -471,6 +471,18 @@ config PCI_ENDPOINT_TEST
> > > Enable this configuration option to enable the host side test driver
> > > for PCI Endpoint.
> > >
> > > +config XILINX_SDFEC
> > > + tristate "Xilinx SDFEC 16"
> > > + help
> > > + This option enables support for the Xilinx SDFEC (Soft Decision
> > > + Forward Error Correction) driver. This enables a char driver
> > > + for the SDFEC.
> > > +
> > > + You may select this driver if your design instantiates the
> > > + SDFEC(16nm) hardened block. To compile this as a module choose M.
> > > +
> > > + If unsure, say N.
> > > +
> > > config MISC_RTSX
> > > tristate
> > > default MISC_RTSX_PCI || MISC_RTSX_USB
> > > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> > > index b9affcd..0cb3546 100644
> > > --- a/drivers/misc/Makefile
> > > +++ b/drivers/misc/Makefile
> > > @@ -59,3 +59,4 @@ obj-$(CONFIG_OCXL) += ocxl/
> > > obj-y += cardreader/
> > > obj-$(CONFIG_PVPANIC) += pvpanic.o
> > > obj-$(CONFIG_HABANA_AI) += habanalabs/
> > > +obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
> > > diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
> > > new file mode 100644
> > > index 0000000..75cc980
> > > --- /dev/null
> > > +++ b/drivers/misc/xilinx_sdfec.c
> > > @@ -0,0 +1,118 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Xilinx SDFEC
> > > + *
> > > + * Copyright (C) 2019 Xilinx, Inc.
> > > + *
> > > + * Description:
> > > + * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
> > > + * IP. It exposes a char device which supports file operations
> > > + * like open(), close() and ioctl().
> > > + */
> > > +
> > > +#include <linux/miscdevice.h>
> > > +#include <linux/io.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of_platform.h>
> > > +#include <linux/poll.h>
> > > +#include <linux/slab.h>
> > > +#include <linux/clk.h>
> > > +
> > > +static int xsdfec_ndevs;
> >
> > You should use an idr for this, not just a number you bump up and down.
> > This will not work properly at all.
> >
> > Think about this situation:
> > probe device 0
> > xsdfec_ndevs = 1
> > probe device 1
> > xsdfec_ndevs = 2
> > remove device 0
> > xsdfec_ndevs = 0
> > probe another device
> > misc device fails due to duplicate name.
> >
>
> My bad.
> I can use idr, but couldn't be better optimized code if use simple mutex to protect the variable.
mutex does not protect from this at all, it's a logic bug. Think about
adding 5 devices and then removing the 2nd one. What is the number
assigned to the new device that is added afterward?
And you need a mutex for the idr anyway, if you are touching it in a non
probe/release callback way (those are already serialized by the bus
lock).
thanks,
greg k-h