[PATCH 02/12] misc: xilinx-sdfec: add core driver

From: Dragan Cvetic
Date: Tue Mar 19 2019 - 08:05:35 EST

Implements an 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.

Reviewed-by: Michal Simek <michal.simek@xxxxxxxxxx>
Tested-by: Dragan Cvetic <dragan.cvetic@xxxxxxxxxx>
Signed-off-by: Derek Kiernan <derek.kiernan@xxxxxxxxxx>
Signed-off-by: Dragan Cvetic <dragan.cvetic@xxxxxxxxxx>
---
drivers/misc/Kconfig | 12 +++
drivers/misc/Makefile | 1 +
drivers/misc/xilinx_sdfec.c | 215 +++++++++++++++++++++++++++++++++++++++
include/uapi/misc/xilinx_sdfec.h | 42 ++++++++
4 files changed, 270 insertions(+)
create mode 100644 drivers/misc/xilinx_sdfec.c
create mode 100644 include/uapi/misc/xilinx_sdfec.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 42ab8ec..bbb868f 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -520,6 +520,18 @@ 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 d5b7d34..08f0906 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/
obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o
obj-$(CONFIG_SRAM) += sram.o
obj-$(CONFIG_SRAM_EXEC) += sram-exec.o
+obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
obj-y += mic/
obj-$(CONFIG_GENWQE) += genwqe/
obj-$(CONFIG_ECHO) += echo/
diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
new file mode 100644
index 0000000..278754b
--- /dev/null
+++ b/drivers/misc/xilinx_sdfec.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx SDFEC
+ *
+ * Copyright (C) 2016 - 2017 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
+ * IP. It exposes a char device interface in sysfs and supports file
+ * operations like open(), close() and ioctl().
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+
+#include <uapi/misc/xilinx_sdfec.h>
+
+#define DRIVER_NAME "xilinx_sdfec"
+#define DRIVER_VERSION "0.3"
+#define DRIVER_MAX_DEV BIT(MINORBITS)
+
+static struct class *xsdfec_class;
+static atomic_t xsdfec_ndevs = ATOMIC_INIT(0);
+static dev_t xsdfec_devt;
+
+/**
+ * struct xsdfec_dev - Driver data for SDFEC
+ * @regs: device physical base address
+ * @dev: pointer to device struct
+ * @config: Configuration of the SDFEC device
+ * @open_count: Count of char device being opened
+ * @xsdfec_cdev: Character device handle
+ * @irq_lock: Driver spinlock
+ *
+ * This structure contains necessary state for SDFEC driver to operate
+ */
+struct xsdfec_dev {
+ void __iomem *regs;
+ struct device *dev;
+ struct xsdfec_config config;
+ atomic_t open_count;
+ struct cdev xsdfec_cdev;
+ /* Spinlock to protect state_updated and stats_updated */
+ spinlock_t irq_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 device *dev_create;
+ struct resource *res;
+ int err;
+
+ xsdfec = devm_kzalloc(&pdev->dev, sizeof(*xsdfec), GFP_KERNEL);
+ if (!xsdfec)
+ return -ENOMEM;
+
+ xsdfec->dev = &pdev->dev;
+ xsdfec->config.fec_id = atomic_read(&xsdfec_ndevs);
+ spin_lock_init(&xsdfec->irq_lock);
+
+ dev = xsdfec->dev;
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ xsdfec->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(xsdfec->regs)) {
+ dev_err(dev, "Unable to map resource");
+ err = PTR_ERR(xsdfec->regs);
+ goto err_xsdfec_dev;
+ }
+
+ /* Save driver private data */
+ platform_set_drvdata(pdev, xsdfec);
+
+ cdev_init(&xsdfec->xsdfec_cdev, &xsdfec_fops);
+ xsdfec->xsdfec_cdev.owner = THIS_MODULE;
+ err = cdev_add(&xsdfec->xsdfec_cdev,
+ MKDEV(MAJOR(xsdfec_devt), xsdfec->config.fec_id), 1);
+ if (err < 0) {
+ dev_err(dev, "cdev_add failed");
+ err = -EIO;
+ goto err_xsdfec_dev;
+ }
+
+ if (!xsdfec_class) {
+ err = -EIO;
+ dev_err(dev, "xsdfec class not created correctly");
+ goto err_xsdfec_cdev;
+ }
+
+ dev_create =
+ device_create(xsdfec_class, dev,
+ MKDEV(MAJOR(xsdfec_devt), xsdfec->config.fec_id),
+ xsdfec, "xsdfec%d", xsdfec->config.fec_id);
+ if (IS_ERR(dev_create)) {
+ dev_err(dev, "unable to create device");
+ err = PTR_ERR(dev_create);
+ goto err_xsdfec_cdev;
+ }
+
+ atomic_set(&xsdfec->open_count, 1);
+ dev_info(dev, "XSDFEC%d Probe Successful", xsdfec->config.fec_id);
+ atomic_inc(&xsdfec_ndevs);
+ return 0;
+
+ /* Failure cleanup */
+err_xsdfec_cdev:
+ cdev_del(&xsdfec->xsdfec_cdev);
+err_xsdfec_dev:
+ return err;
+}
+
+static int xsdfec_remove(struct platform_device *pdev)
+{
+ struct xsdfec_dev *xsdfec;
+ struct device *dev = &pdev->dev;
+
+ xsdfec = platform_get_drvdata(pdev);
+ if (!xsdfec)
+ return -ENODEV;
+
+ if (!xsdfec_class) {
+ dev_err(dev, "xsdfec_class is NULL");
+ return -EIO;
+ }
+
+ device_destroy(xsdfec_class,
+ MKDEV(MAJOR(xsdfec_devt), xsdfec->config.fec_id));
+ cdev_del(&xsdfec->xsdfec_cdev);
+ atomic_dec(&xsdfec_ndevs);
+ 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,
+};
+
+static int __init xsdfec_init_mod(void)
+{
+ int err;
+
+ xsdfec_class = class_create(THIS_MODULE, DRIVER_NAME);
+ if (IS_ERR(xsdfec_class)) {
+ err = PTR_ERR(xsdfec_class);
+ pr_err("%s : Unable to register xsdfec class", __func__);
+ return err;
+ }
+
+ err = alloc_chrdev_region(&xsdfec_devt, 0, DRIVER_MAX_DEV, DRIVER_NAME);
+ if (err < 0) {
+ pr_err("%s : Unable to get major number", __func__);
+ goto err_xsdfec_class;
+ }
+
+ err = platform_driver_register(&xsdfec_driver);
+ if (err < 0) {
+ pr_err("%s Unabled to register %s driver", __func__,
+ DRIVER_NAME);
+ goto err_xsdfec_drv;
+ }
+ return 0;
+
+ /* Error Path */
+err_xsdfec_drv:
+ unregister_chrdev_region(xsdfec_devt, DRIVER_MAX_DEV);
+err_xsdfec_class:
+ class_destroy(xsdfec_class);
+ return err;
+}
+
+static void __exit xsdfec_cleanup_mod(void)
+{
+ platform_driver_unregister(&xsdfec_driver);
+ unregister_chrdev_region(xsdfec_devt, DRIVER_MAX_DEV);
+ class_destroy(xsdfec_class);
+ xsdfec_class = NULL;
+}
+
+module_init(xsdfec_init_mod);
+module_exit(xsdfec_cleanup_mod);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("Xilinx SD-FEC16 Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
diff --git a/include/uapi/misc/xilinx_sdfec.h b/include/uapi/misc/xilinx_sdfec.h
new file mode 100644
index 0000000..5543163
--- /dev/null
+++ b/include/uapi/misc/xilinx_sdfec.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Xilinx SD-FEC
+ *
+ * Copyright (C) 2016 - 2017 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for SDFEC16 IP. It provides a char device
+ * in sysfs and supports file operations like open(), close() and ioctl().
+ */
+#ifndef __XILINX_SDFEC_H__
+#define __XILINX_SDFEC_H__
+
+/**
+ * enum xsdfec_state - State.
+ * @XSDFEC_INIT: Driver is initialized.
+ * @XSDFEC_STARTED: Driver is started.
+ * @XSDFEC_STOPPED: Driver is stopped.
+ * @XSDFEC_NEEDS_RESET: Driver needs to be reset.
+ * @XSDFEC_PL_RECONFIGURE: Programmable Logic needs to be recofigured.
+ *
+ * This enum is used to indicate the state of the driver.
+ */
+enum xsdfec_state {
+ XSDFEC_INIT = 0,
+ XSDFEC_STARTED,
+ XSDFEC_STOPPED,
+ XSDFEC_NEEDS_RESET,
+ XSDFEC_PL_RECONFIGURE,
+};
+
+/**
+ * struct xsdfec_config - Configuration of SD-FEC core.
+ * @fec_id: ID of SD-FEC instance. ID is limited to the number of active
+ * SD-FEC's in the FPGA and is related to the driver instance
+ * Minor number.
+ */
+struct xsdfec_config {
+ s32 fec_id;
+};
+
+#endif /* __XILINX_SDFEC_H__ */
--
2.7.4

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