[PATCH v2 1/8] usb: Add MA-USB Host kernel module

[Vladimir Stankovic]

Added utility macros, kernel device creation and cleanup, functions for
handling log formatting and a placeholder module for MA-USB Host device
driver.

Signed-off-by: Vladimir Stankovic <vladimir.stankovic@xxxxxxxxxxxxxxx>
---
  MAINTAINERS                         |  7 +++
  drivers/usb/Kconfig                 |  2 +
  drivers/usb/Makefile                |  2 +
  drivers/usb/mausb_host/Kconfig      | 14 +++++
  drivers/usb/mausb_host/Makefile     | 13 +++++
  drivers/usb/mausb_host/mausb_host.c | 90 +++++++++++++++++++++++++++++
  drivers/usb/mausb_host/utils.c      | 85 +++++++++++++++++++++++++++
  drivers/usb/mausb_host/utils.h      | 40 +++++++++++++
  8 files changed, 253 insertions(+)
  create mode 100644 drivers/usb/mausb_host/Kconfig
  create mode 100644 drivers/usb/mausb_host/Makefile
  create mode 100644 drivers/usb/mausb_host/mausb_host.c
  create mode 100644 drivers/usb/mausb_host/utils.c
  create mode 100644 drivers/usb/mausb_host/utils.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 8f27f40d22bb..6088f9aa640a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10226,6 +10226,13 @@ W:	https://linuxtv.org
  S:	Maintained
  F:	drivers/media/radio/radio-maxiradio*
  +MA USB HOST DRIVER
+M:	Vladimir Stankovic <vladimir.stankovic@xxxxxxxxxxxxxxx>
+L:	mausb-host-devel@xxxxxxxxxxxxxxx
+W:	https://www.displaylink.com
+S:	Maintained
+F:	drivers/usb/mausb_host/*
+
  MCAN MMIO DEVICE DRIVER
  M:	Dan Murphy <dmurphy@xxxxxx>
  M:	Sriram Dash <sriram.dash@xxxxxxxxxxx>
diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
index 275568abc670..4e92f1fa0fa5 100644
--- a/drivers/usb/Kconfig
+++ b/drivers/usb/Kconfig
@@ -164,6 +164,8 @@ source "drivers/usb/misc/Kconfig"
   source "drivers/usb/atm/Kconfig"
  +source "drivers/usb/mausb_host/Kconfig"
+
  endif # USB
   source "drivers/usb/phy/Kconfig"
diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index 1c1c1d659394..22d1998db0e2 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile
@@ -66,3 +66,5 @@ obj-$(CONFIG_USBIP_CORE)	+= usbip/
  obj-$(CONFIG_TYPEC)		+= typec/
   obj-$(CONFIG_USB_ROLE_SWITCH)	+= roles/
+
+obj-$(CONFIG_HOST_MAUSB)        += mausb_host/
diff --git a/drivers/usb/mausb_host/Kconfig b/drivers/usb/mausb_host/Kconfig
new file mode 100644
index 000000000000..2465aac713fe
--- /dev/null
+++ b/drivers/usb/mausb_host/Kconfig
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Kernel configuration file for MA-USB Host driver.
+#
+# Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+#
+
+config HOST_MAUSB
+	tristate "MA-USB Host Driver"
+	depends on USB=y
+	default n
+	help
+		This is a MA-USB Host driver which enables host communication
+		via MA-USB protocol stack.
diff --git a/drivers/usb/mausb_host/Makefile 
b/drivers/usb/mausb_host/Makefile
new file mode 100644
index 000000000000..ad7fec4d9ff9
--- /dev/null
+++ b/drivers/usb/mausb_host/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for DisplayLink MA-USB Host driver.
+#
+# Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+#
+
+obj-$(CONFIG_HOST_MAUSB) += mausb_host.o
+mausb_host-y := mausb_host.o
+mausb_host-y += utils.o
+
+ccflags-y += -I$(srctree)/$(src)
+ccflags-y += -g
diff --git a/drivers/usb/mausb_host/mausb_host.c 
b/drivers/usb/mausb_host/mausb_host.c
new file mode 100644
index 000000000000..8638dd0a4856
--- /dev/null
+++ b/drivers/usb/mausb_host/mausb_host.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+ */
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/net.h>
+
+#include "utils.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("DisplayLink (UK) Ltd.");
+MODULE_VERSION(MAUSB_DRIVER_VERSION);
+
+static int mausb_client_connect(const char *value,
+				const struct kernel_param *kp)
+{
+	mausb_pr_info("Version=%s", MAUSB_DRIVER_VERSION);
+
+	return 0;
+}
+
+static int mausb_client_disconnect(const char *value,
+				   const struct kernel_param *kp)
+{
+	mausb_pr_info("Version=%s", MAUSB_DRIVER_VERSION);
+
+	return 0;
+}
+
+static int mausb_device_connect(const char *value,
+				const struct kernel_param *kp)
+{
+	mausb_pr_info("Version=%s", MAUSB_DRIVER_VERSION);
+
+	return 0;
+}
+
+static int mausb_device_disconnect(const char *value,
+				   const struct kernel_param *kp)
+{
+	mausb_pr_info("Version=%s", MAUSB_DRIVER_VERSION);
+
+	return 0;
+}
+
+static const struct kernel_param_ops mausb_device_connect_ops = {
+	.set = mausb_device_connect
+};
+
+static const struct kernel_param_ops mausb_device_disconnect_ops = {
+	.set = mausb_device_disconnect
+};
+
+static const struct kernel_param_ops mausb_client_connect_ops = {
+	.set = mausb_client_connect
+};
+
+static const struct kernel_param_ops mausb_client_disconnect_ops = {
+	.set = mausb_client_disconnect
+};
+
+static int mausb_host_init(void)
+{
+	int status = mausb_create_dev();
+
+	mausb_pr_info("Module load. Version=%s", MAUSB_DRIVER_VERSION);
+
+	if (status < 0) {
+		mausb_pr_alert("Failed to load MAUSB module!");
+		return status;
+	}
+
+	return 0;
+}
+
+static void mausb_host_exit(void)
+{
+	mausb_pr_info("Module unloading started...");
+	mausb_cleanup_dev(1);
+	mausb_pr_info("Module unloaded. Version=%s", MAUSB_DRIVER_VERSION);
+}
+
+module_init(mausb_host_init);
+module_exit(mausb_host_exit);
diff --git a/drivers/usb/mausb_host/utils.c b/drivers/usb/mausb_host/utils.c
new file mode 100644
index 000000000000..c055b578e402
--- /dev/null
+++ b/drivers/usb/mausb_host/utils.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+ */
+#include "utils.h"
+
+#include <linux/atomic.h>
+#include <linux/cdev.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#define MAUSB_KERNEL_DEV_NAME "mausb_host"
+#define MAUSB_READ_DEVICE_TIMEOUT_MS 500
+
+static dev_t mausb_major_kernel;
+static struct cdev  mausb_kernel_dev;
+static struct class *mausb_kernel_class;
+
+static int mausb_file_open(struct inode *inode, struct file *filp)
+{
+	filp->private_data = NULL;
+
+	return 0;
+}
+
+static int mausb_file_close(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	filp->private_data = NULL;
+
+	return 0;
+}
+
+static const struct file_operations mausb_file_ops = {
+	.open	 = mausb_file_open,
+	.release = mausb_file_close,
+};
+
+int mausb_create_dev(void)
+{
+	int device_created = 0;
+	int status = alloc_chrdev_region(&mausb_major_kernel, 0, 1,
+					 MAUSB_KERNEL_DEV_NAME "_proc");
+	if (status)
+		goto cleanup;
+
+	mausb_kernel_class = class_create(THIS_MODULE,
+					  MAUSB_KERNEL_DEV_NAME "_sys");
+	if (!mausb_kernel_class) {
+		status = -ENOMEM;
+		goto cleanup;
+	}
+
+	if (!device_create(mausb_kernel_class, NULL, mausb_major_kernel, NULL,
+			   MAUSB_KERNEL_DEV_NAME "_dev")) {
+		status = -ENOMEM;
+		goto cleanup;
+	}
+	device_created = 1;
+	cdev_init(&mausb_kernel_dev, &mausb_file_ops);
+	status = cdev_add(&mausb_kernel_dev, mausb_major_kernel, 1);
+	if (status)
+		goto cleanup;
+	return 0;
+cleanup:
+	mausb_cleanup_dev(device_created);
+	return status;
+}
+
+void mausb_cleanup_dev(int device_created)
+{
+	if (device_created) {
+		device_destroy(mausb_kernel_class, mausb_major_kernel);
+		cdev_del(&mausb_kernel_dev);
+	}
+
+	if (mausb_kernel_class)
+		class_destroy(mausb_kernel_class);
+
+	unregister_chrdev_region(mausb_major_kernel, 1);
+}
diff --git a/drivers/usb/mausb_host/utils.h b/drivers/usb/mausb_host/utils.h
new file mode 100644
index 000000000000..a5378ee4c4f0
--- /dev/null
+++ b/drivers/usb/mausb_host/utils.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+ */
+#ifndef __MAUSB_UTILS_H__
+#define __MAUSB_UTILS_H__
+
+#if defined(MAUSB_NO_LOGS)
+#define mausb_pr_logs(...)
+#else
+#include <linux/printk.h>
+#include <linux/sched.h>
+#define mausb_pr_logs(level_str, level, log, ...)\
+	pr_##level_str("MAUSB " #level " [%x:%x] [%s] " log "\n",\
+	current->pid, current->tgid, __func__, ##__VA_ARGS__)
+#endif /* MAUSB_NO_LOGS */
+
+#define mausb_pr_alert(...) mausb_pr_logs(alert, 1, ##__VA_ARGS__)
+
+#define mausb_pr_err(...) mausb_pr_logs(err, 2, ##__VA_ARGS__)
+
+#define mausb_pr_warn(...) mausb_pr_logs(warn, 3, ##__VA_ARGS__)
+
+#define mausb_pr_info(...)  mausb_pr_logs(info, 4, ##__VA_ARGS__)
+
+#if defined(MAUSB_LOG_VERBOSE)
+	#define mausb_pr_debug(...) mausb_pr_logs(debug, 5, ##__VA_ARGS__)
+#else
+	#define mausb_pr_debug(...)
+#endif /* defined(MAUSB_LOG_VERBOSE) */
+
+#define MAUSB_STRINGIFY2(x) #x
+#define MAUSB_STRINGIFY(x) MAUSB_STRINGIFY2(x)
+
+#define MAUSB_DRIVER_VERSION MAUSB_STRINGIFY(1.2.0.0.fb3296e6)
+
+int mausb_create_dev(void);
+void mausb_cleanup_dev(int device_created);
+
+#endif /* __MAUSB_UTILS_H__ */
-- 
2.17.1