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0013-Integration-of-CBC-line-discipline-kernel-module.patch
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0013-Integration-of-CBC-line-discipline-kernel-module.patch
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "G Jaya Kumaran, Vineetha" <[email protected]>
Date: Thu, 24 May 2018 18:45:28 +0800
Subject: [PATCH] Integration of CBC line discipline kernel module
This patch enables the Carrier Board Communication (CBC)
kernel module, which is implemented as a Linux kernel line
discipline attached to a UART device. The CBC protocol
defines a number of different channels which are provided
as Linux character device nodes.
Change-Id: Ic2a72229df9e9a80e306f2f44da37b1ac8539af3
Signed-off-by: G Jaya Kumaran, Vineetha
---
drivers/tty/Kconfig | 2 +
drivers/tty/Makefile | 1 +
drivers/tty/cbc/Kconfig | 22 +
drivers/tty/cbc/Makefile | 14 +
drivers/tty/cbc/cbc_core.c | 307 +++++++++
drivers/tty/cbc/cbc_core.h | 44 ++
drivers/tty/cbc/cbc_core_public.h | 28 +
drivers/tty/cbc/cbc_device.c | 66 ++
drivers/tty/cbc/cbc_device.h | 107 ++++
drivers/tty/cbc/cbc_device_manager.c | 879 ++++++++++++++++++++++++++
drivers/tty/cbc/cbc_device_manager.h | 66 ++
drivers/tty/cbc/cbc_link_checksum.c | 59 ++
drivers/tty/cbc/cbc_link_checksum.h | 44 ++
drivers/tty/cbc/cbc_link_layer.c | 484 ++++++++++++++
drivers/tty/cbc/cbc_link_layer.h | 38 ++
drivers/tty/cbc/cbc_memory.c | 153 +++++
drivers/tty/cbc/cbc_memory.h | 146 +++++
drivers/tty/cbc/cbc_mux_multiplexer.c | 145 +++++
drivers/tty/cbc/cbc_mux_multiplexer.h | 62 ++
drivers/tty/cbc/cbc_types.h | 137 ++++
include/cbc/cbc-core.h | 24 +
include/uapi/linux/cbc/cbc-core.h | 24 +
include/uapi/linux/major.h | 2 +
include/uapi/linux/tty.h | 5 +-
24 files changed, 2857 insertions(+), 2 deletions(-)
create mode 100644 drivers/tty/cbc/Kconfig
create mode 100644 drivers/tty/cbc/Makefile
create mode 100644 drivers/tty/cbc/cbc_core.c
create mode 100644 drivers/tty/cbc/cbc_core.h
create mode 100644 drivers/tty/cbc/cbc_core_public.h
create mode 100644 drivers/tty/cbc/cbc_device.c
create mode 100644 drivers/tty/cbc/cbc_device.h
create mode 100644 drivers/tty/cbc/cbc_device_manager.c
create mode 100644 drivers/tty/cbc/cbc_device_manager.h
create mode 100644 drivers/tty/cbc/cbc_link_checksum.c
create mode 100644 drivers/tty/cbc/cbc_link_checksum.h
create mode 100644 drivers/tty/cbc/cbc_link_layer.c
create mode 100644 drivers/tty/cbc/cbc_link_layer.h
create mode 100644 drivers/tty/cbc/cbc_memory.c
create mode 100644 drivers/tty/cbc/cbc_memory.h
create mode 100644 drivers/tty/cbc/cbc_mux_multiplexer.c
create mode 100644 drivers/tty/cbc/cbc_mux_multiplexer.h
create mode 100644 drivers/tty/cbc/cbc_types.h
create mode 100644 include/cbc/cbc-core.h
create mode 100644 include/uapi/linux/cbc/cbc-core.h
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index e0a04bfc873e..7bd645d4ed46 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -442,6 +442,8 @@ config VCC
help
Support for Sun logical domain consoles.
+source "drivers/tty/cbc/Kconfig"
+
config LDISC_AUTOLOAD
bool "Automatically load TTY Line Disciplines"
default y
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index c72cafdf32b4..4ae6744406d4 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -33,5 +33,6 @@ obj-$(CONFIG_PPC_EPAPR_HV_BYTECHAN) += ehv_bytechan.o
obj-$(CONFIG_GOLDFISH_TTY) += goldfish.o
obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o
obj-$(CONFIG_VCC) += vcc.o
+obj-$(CONFIG_CBC_LDISC) += cbc/
obj-y += ipwireless/
diff --git a/drivers/tty/cbc/Kconfig b/drivers/tty/cbc/Kconfig
new file mode 100644
index 000000000000..c9cde7fa43ca
--- /dev/null
+++ b/drivers/tty/cbc/Kconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# CBC (CarrierBoardCommunication) subsystem configuration
+#
+
+config CBC_LDISC
+ tristate "CBC (Carrier Board Communication) line discipline"
+ depends on TTY
+ help
+ The CBC driver implements a line discipline supporting
+ the proprietary CBC (Carrier Board Communication) protocol.
+
+ The CBC protocol is a serial line protocol with multiplexing
+ intended to be used in automotive IVI platforms for multi-
+ plexed communication between a vehicle IOC and CPU. It is
+ designed to transport small data packets (up to 64 bytes)
+ and features a transport protocol to transport larger data
+ chunks over a point to point connection.
+
+ When initialised the driver presents a number of channels as
+ character devices.
+
diff --git a/drivers/tty/cbc/Makefile b/drivers/tty/cbc/Makefile
new file mode 100644
index 000000000000..c0517817f605
--- /dev/null
+++ b/drivers/tty/cbc/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+
+
+cbc-ldisc-y := cbc_core.o
+cbc-ldisc-y += cbc_device.o
+cbc-ldisc-y += cbc_device_manager.o
+cbc-ldisc-y += cbc_link_checksum.o
+cbc-ldisc-y += cbc_link_layer.o
+cbc-ldisc-y += cbc_memory.o
+cbc-ldisc-y += cbc_mux_multiplexer.o
+
+obj-$(CONFIG_CBC_LDISC) += cbc-ldisc.o
+
+ccflags-y := -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -fstack-protector
\ No newline at end of file
diff --git a/drivers/tty/cbc/cbc_core.c b/drivers/tty/cbc/cbc_core.c
new file mode 100644
index 000000000000..d9d15fa224ae
--- /dev/null
+++ b/drivers/tty/cbc/cbc_core.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/uaccess.h>
+
+#include "cbc_core.h"
+#include "cbc_types.h"
+#include "cbc_device_manager.h"
+#include "cbc_link_layer.h"
+#include "cbc_mux_multiplexer.h"
+
+MODULE_AUTHOR("Gerhard Bocksch. [email protected]");
+MODULE_DESCRIPTION("CBC serial protocol demultiplexer");
+MODULE_LICENSE("GPL");
+
+static int granularity = 4;
+module_param(granularity, int, 0644);
+MODULE_PARM_DESC(granularity,
+ "The granularity of the CBC messages. default: 4");
+
+MODULE_ALIAS_LDISC(N_CBCCORE);
+
+/* Marker to mark the cbc_core as valid. */
+#define CBC_MAGIC 0xAFFEAFFE
+
+static struct cbc_struct cbc_core = { .magic = CBC_MAGIC };
+
+/*
+ * cbc_core_configure_channel - Set the priority and receive
+ * callback for a CBC channel.
+ * @channel_idx: Channel identifier (see cbc_channel_enumeration)
+ * @priority: Priority for channel.
+ * @data: Data associated with channel.
+ * @receive: Receive callback associated with channel.
+ */
+void cbc_core_configure_channel(u32 const channel_idx, const u8 priority,
+ void *data,
+ void (*receive)(void *data, const u16 length,
+ const u8 * const buffer))
+{
+ cbc_mux_configure_data_channel(channel_idx, priority, data, receive);
+}
+EXPORT_SYMBOL_GPL(cbc_core_configure_channel);
+
+/*
+ * cbc_core_send_data - Send to a CBC channel.
+ * @channel_idx: Channel identifier (see cbc_channel_enumeration)
+ * @priority: Priority for channel.
+ * @data: Data associated with channel.
+ * @receive: Receive function associated with channel.
+ */
+void cbc_core_send_data(const u32 channel_idx, const u16 length,
+ const u8 * const buffer)
+{
+ cbc_manager_transmit_data(channel_idx, length, buffer);
+}
+EXPORT_SYMBOL_GPL(cbc_core_send_data);
+
+/*
+ * cbc_ldisc_open - Open the CBC connection to the IOC.
+ * @tty: Handle to tty.
+ *
+ * This function is called by the tty module when the
+ * line discipline is requested. It allocates the memory pool and creates the
+ * CBC devices.
+ * Called in process context serialized from other ldisc calls.
+ *
+ * Return: 0 on success error otherwise.
+ */
+static int cbc_ldisc_open(struct tty_struct *tty)
+{
+ struct cbc_struct *cbc;
+ int err;
+
+ pr_debug("cbc-ldisc open.\n");
+ mutex_lock(&cbc_core.ldisc_mutex);
+
+ if (WARN_ON(tty->ops->write == NULL)) {
+ pr_err("cbc-ldisc open write not supported.\n");
+ err = -EOPNOTSUPP;
+ goto err_exit;
+ }
+
+ cbc = tty->disc_data;
+
+ err = -EEXIST;
+ /* First make sure we're not already connected. */
+ if (WARN_ON(cbc && cbc->magic == CBC_MAGIC)) {
+ pr_err(
+ "cbc-ldisc CBC line discipline already open or CBC magic wrong.\n");
+ goto err_exit;
+ }
+
+ cbc = &cbc_core;
+
+ cbc->tty = tty;
+ tty->disc_data = cbc;
+ tty->receive_room = 65536;
+
+ /* Create class cbc-core. This will appear as /sys/class/cbc* */
+ cbc->cbc_class = class_create(THIS_MODULE, "cbc");
+
+ if (WARN_ON(!cbc->cbc_class)) {
+ pr_err("cbc-ldisc open could not create cbc class.\n");
+ goto err_exit;
+ }
+
+ /* Create memory pool */
+ cbc->memory_pool = cbc_memory_pool_create(
+ CBC_QUEUE_LENGTH * CBC_CHANNEL_MAX_NUMBER);
+ if (WARN_ON(!cbc->memory_pool)) {
+ pr_err("failed to create memory pool.\n");
+ goto err_exit;
+ }
+
+ /* Initialise on every open, so we start with sequence-counters at 0.*/
+ cbc_link_layer_init(cbc->memory_pool);
+
+ /* Register devices here. */
+ err = cbc_register_devices(cbc->cbc_class, cbc->memory_pool);
+ if (err != 0) {
+ pr_err("register devices failed\n");
+ goto err_exit;
+ }
+
+ cbc_link_layer_set_frame_granularity(granularity);
+
+ /* tty layer expects 0 on success */
+ mutex_unlock(&cbc_core.ldisc_mutex);
+ return 0;
+
+err_exit: mutex_unlock(&cbc_core.ldisc_mutex);
+ return err;
+}
+
+/*
+ * cbc_ldisc_close - Close down the CBC communication.
+ * @tty: Handle to tty
+ *
+ * Unregister CBC devices and destroy CBC class.
+ */
+static void cbc_ldisc_close(struct tty_struct *tty)
+{
+ struct cbc_struct *cbc;
+
+ mutex_lock(&cbc_core.ldisc_mutex);
+
+ cbc = (struct cbc_struct *) tty->disc_data;
+ pr_debug("cbc-ldisc close\n");
+
+ if (cbc && cbc->magic == CBC_MAGIC && cbc->tty == tty) {
+ cbc_unregister_devices(cbc->cbc_class);
+ class_destroy(cbc->cbc_class);
+ if (WARN_ON(!cbc_memory_pool_try_free(cbc->memory_pool)))
+ pr_err("could not free memory pool.\n");
+ tty->disc_data = NULL;
+ cbc->tty = NULL;
+ } else {
+ WARN_ON(1);
+ pr_err("ldisc close with wrong CBC magic.\n");
+ }
+
+ mutex_unlock(&cbc_core.ldisc_mutex);
+}
+
+/*
+ * Close line discipline on ldisc hangup.
+ * @tty: Handle to tty
+ */
+static int cbc_ldisc_hangup(struct tty_struct *tty)
+{
+ cbc_ldisc_close(tty);
+ return 0;
+}
+
+/*
+ * cbc_ldisc_receive_buf - .receive call for a line discipline.
+ * @tty: Handle to tty
+ * @cp: Received data buffer.
+ * @fp: Not used
+ * @count: Amount of data received.
+ *
+ * Attempts to read a single CBC frame at a time. Cycles round
+ * until all data has been processed.
+ */
+static void cbc_ldisc_receive_buf(struct tty_struct *tty,
+ const unsigned char *cp, char *fp, int count)
+{
+ struct cbc_struct *cbc;
+ u8 accepted_bytes; /* per cbc_serial_receive call */
+ unsigned int accepted_bytes_sum = 0;
+
+ mutex_lock(&cbc_core.ldisc_mutex);
+ cbc = (struct cbc_struct *) tty->disc_data;
+
+ if (cbc && (cbc->magic == CBC_MAGIC) && (cbc->tty == tty)) {
+ do {
+ u8 chunksize = 254;
+
+ if ((count - accepted_bytes_sum) < 255)
+ chunksize = count - accepted_bytes_sum;
+ accepted_bytes = cbc_core_on_receive_cbc_serial_data(
+ chunksize, cp + accepted_bytes_sum);
+ accepted_bytes_sum += accepted_bytes;
+ cbc_link_layer_rx_handler();
+ } while (accepted_bytes_sum != count);
+ }
+ mutex_unlock(&cbc_core.ldisc_mutex);
+}
+
+/*
+ * Called from ldisc when write is possible. Not used.
+ */
+static void cbc_ldisc_write_wakeup(struct tty_struct *tty)
+{
+ (void) tty;
+}
+
+/* Called to send messages from channel specific device to the IOC */
+enum cbc_error target_specific_send_cbc_uart_data(u16 length,
+ const u8 *raw_buffer)
+{
+ mutex_lock(&cbc_core.ldisc_mutex);
+ if (cbc_core.tty) {
+ set_bit(TTY_DO_WRITE_WAKEUP, &cbc_core.tty->flags);
+
+ cbc_core.tty->ops->write(cbc_core.tty, raw_buffer, length);
+ }
+ mutex_unlock(&cbc_core.ldisc_mutex);
+
+ return CBC_OK;
+}
+
+static struct tty_ldisc_ops cbc_ldisc = {
+ .owner = THIS_MODULE,
+ .name = "cbc-ldisc",
+ .magic = TTY_LDISC_MAGIC,
+ .open = cbc_ldisc_open,
+ .close = cbc_ldisc_close,
+ .hangup = cbc_ldisc_hangup,
+ .receive_buf = cbc_ldisc_receive_buf,
+ .write_wakeup = cbc_ldisc_write_wakeup
+};
+
+/*
+ * cbc_init - Module init call.
+ * Registers this module as TTY line discipline.
+ */
+static int __init cbc_init(void)
+{
+ int status;
+
+ pr_debug("cbc-ldisc init\n");
+ mutex_init(&cbc_core.ldisc_mutex);
+ mutex_lock(&cbc_core.ldisc_mutex);
+
+ cbc_kmod_devices_init();
+
+ /* Fill in line discipline, and register it */
+ status = tty_register_ldisc(N_CBCCORE, &cbc_ldisc);
+ if (status)
+ pr_err("cbc-ldisc: can't register line discipline\n");
+
+ mutex_unlock(&cbc_core.ldisc_mutex);
+ return 0;
+}
+
+/*
+ * cbc_exit - Module exit call.
+ *
+ * De-registers itself as line discipline.
+ */
+static void __exit cbc_exit(void)
+{
+ int i;
+
+ mutex_lock(&cbc_core.ldisc_mutex);
+
+ pr_debug("cbc-ldisc Exit\n");
+
+ i = tty_unregister_ldisc(N_CBCCORE);
+ if (i)
+ pr_err("cbc-ldisc: can't unregister ldisc (err %d).\n", i);
+
+ mutex_unlock(&cbc_core.ldisc_mutex);
+}
+
+module_init(cbc_init);
+module_exit(cbc_exit);
diff --git a/drivers/tty/cbc/cbc_core.h b/drivers/tty/cbc/cbc_core.h
new file mode 100644
index 000000000000..71e07a3f7765
--- /dev/null
+++ b/drivers/tty/cbc/cbc_core.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef CBC_CORE_MOD_H_
+#define CBC_CORE_MOD_H_
+
+#include <linux/cbc/cbc-core.h>
+#include <linux/cdev.h>
+#include <linux/ioctl.h>
+#include <linux/mutex.h>
+#include <linux/tty.h>
+
+#include "cbc_memory.h"
+
+#define CBC_IOCTL_MAGIC 0xf4
+
+/*
+ * struct cbc_struct -
+ *
+ * @magic: Marker to mark the cbc_core as valid.
+ * @tty: tty associated with the CBC driver.
+ * @class: CBC device class
+ * @memory_pool: Memory pool of CBC buffer allocated for used by CBC driver.
+ * @ldisc_mutex: Mutex to avoid unloading while accessing the driver
+ */
+struct cbc_struct {
+ int magic;
+ struct tty_struct *tty;
+ struct class *cbc_class;
+ struct cbc_memory_pool *memory_pool;
+ struct mutex ldisc_mutex;
+};
+
+#endif /* CBC_CORE_MOD_H_ */
diff --git a/drivers/tty/cbc/cbc_core_public.h b/drivers/tty/cbc/cbc_core_public.h
new file mode 100644
index 000000000000..85928f6efc68
--- /dev/null
+++ b/drivers/tty/cbc/cbc_core_public.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef CBC_CORE_PUBLIC_H
+#define CBC_CORE_PUBLIC_H
+
+#include "cbc_types.h"
+
+/* CBC version. */
+#define CBC_VERSION_ID 1
+
+/* The following function needs to be implemented on CM/IOC. */
+enum cbc_error target_specific_send_cbc_uart_data(u16 length,
+ const u8 *raw_buffer);
+
+
+#endif /* CBC_CORE_PUBLIC_H */
+
diff --git a/drivers/tty/cbc/cbc_device.c b/drivers/tty/cbc/cbc_device.c
new file mode 100644
index 000000000000..1933a8527015
--- /dev/null
+++ b/drivers/tty/cbc/cbc_device.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/sched.h>
+
+#include "cbc_device.h"
+
+
+void cbc_device_init(struct cbc_device_data *cd)
+{
+ if (cd)
+ INIT_LIST_HEAD(&cd->open_files_head);
+}
+
+void cbc_file_init(struct cbc_file_data *file)
+{
+ if (file) {
+ cbc_buffer_queue_init(&file->queue);
+ init_waitqueue_head(&file->wq_read);
+ INIT_LIST_HEAD(&file->list);
+ }
+}
+
+void cbc_file_enqueue(struct cbc_file_data *fd, struct cbc_buffer *buffer)
+{
+ if (fd) {
+ if (cbc_buffer_queue_enqueue(&fd->queue, buffer)) {
+ cbc_buffer_increment_ref(buffer);
+ wake_up_interruptible(&fd->wq_read);
+ }
+ }
+}
+
+struct cbc_buffer *cbc_file_dequeue(struct cbc_file_data *fd)
+{
+ struct cbc_buffer *buffer = NULL;
+
+ if (fd)
+ buffer = cbc_buffer_queue_dequeue(&fd->queue);
+
+ if (buffer && atomic_read(&buffer->refcount) == 0) {
+ buffer = NULL;
+ pr_err("cbc-core: De-queueing an already freed buffer\n");
+ }
+
+ return buffer;
+}
+
+int cbc_file_queue_empty(struct cbc_file_data *fd)
+{
+ if (fd)
+ return (fd->queue.write == fd->queue.read);
+
+ return 1;
+}
+
diff --git a/drivers/tty/cbc/cbc_device.h b/drivers/tty/cbc/cbc_device.h
new file mode 100644
index 000000000000..deb0cd922316
--- /dev/null
+++ b/drivers/tty/cbc/cbc_device.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef CBC_DEVICE_H_
+#define CBC_DEVICE_H_
+
+#include <linux/cdev.h>
+#include <linux/circ_buf.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/wait.h>
+
+
+#include "cbc_types.h"
+#include "cbc_memory.h"
+
+enum cbc_device_type {
+ CBC_DEVICE_TYPE_DEFAULT,
+ CBC_DEVICE_TYPE_RAW,
+ CBC_DEVICE_TYPE_HIDDEN,
+ CBC_DEVICE_TYPE_DEBUG
+};
+
+/*
+ * struct cbc_device_data -Data for a single channel e.g. /dev/cbc-pmt.
+ * @device_name: Device name.
+ * @device_type: CBC device type.
+ * See c:type 'enum cbc_device_type <cbc_device_type>'.
+ * @device: Pointer to device struct.
+ * @open_files_head: Linked list of open files for this device.
+ *
+ * Configuration for a given CBC device. It will be stored in the device private
+ * data.
+ */
+struct cbc_device_data {
+ char *device_name;
+ enum cbc_device_type device_type;
+ struct device *device;
+ struct list_head open_files_head;
+};
+
+/*
+ * struct cbc_file_data - Data for a CBC device file .
+ * @queue: CBC buffer queue for this device.
+ * @wq_read: wait_queue_head_t fused for waking device on events.
+ * @cbc_device: Device data for this device.
+ * @list: list_head.
+ *
+ */
+struct cbc_file_data {
+ struct cbc_buffer_queue queue;
+ wait_queue_head_t wq_read;
+ struct cbc_device_data *cbc_device;
+ struct list_head list;
+};
+
+/*
+ * cbc_device_init - Initialise CBC device data
+ * @cd: pointer to CBC device data.
+ *
+ * Initialises device's list_head.
+ */
+void cbc_device_init(struct cbc_device_data *cd);
+
+/*
+ * cbc_file_init - Initialise CBC file data
+ * @file: pointer to CBC file data.
+ *
+ * Initialises device file's CBC queue, wait_queue_head_t and list_head.
+ */
+void cbc_file_init(struct cbc_file_data *file);
+
+/*
+ * cbc_file_enqueue -Add CBC buffer to queue.
+ * @fd: CBC device file data.
+ * buffer: Pointer to CBC buffer.
+ * Increases reference count on buffer.
+ */
+void cbc_file_enqueue(struct cbc_file_data *fd, struct cbc_buffer *buffer);
+
+/*
+ * cbc_file_dequeue - Remove buffer from head of queue.
+ * @fd: CBC device file data.
+ *
+ * Does not decrease reference count.
+ */
+struct cbc_buffer *cbc_file_dequeue(struct cbc_file_data *fd);
+
+/*
+ * cbc_file_queue_empty - Is CBC queue empty?
+ */
+int cbc_file_queue_empty(struct cbc_file_data *fd);
+
+#endif /* CBC_DEVICE_H_ */
diff --git a/drivers/tty/cbc/cbc_device_manager.c b/drivers/tty/cbc/cbc_device_manager.c
new file mode 100644
index 000000000000..0e74183d9828
--- /dev/null
+++ b/drivers/tty/cbc/cbc_device_manager.c
@@ -0,0 +1,879 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CBC line discipline kernel module.
+ * Handles Carrier Board Communications (CBC) protocol.
+ *
+ * Copyright (C) 2018 Intel Corporation
+ */
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "cbc_core.h"
+#include "cbc_device.h"
+#include "cbc_device_manager.h"
+#include "cbc_memory.h"
+#include "cbc_mux_multiplexer.h"
+#include "cbc_types.h"
+
+static int major; /* Default to dynamic major */
+module_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+
+/*
+ * Minor start number.
+ * This has to be 0 to allow a lookup of the device structs in an array.
+ */
+#define CBC_MINOR 0
+/* Device-name/driver-name when registering the devices in the linux kernel.*/
+#define DEVICE_NAME "cbc-core"
+
+/* Max number of open files per cbc channel */
+#define MAX_OPEN_FILES 6
+
+static void demuxed_receive(void *void_data, struct cbc_buffer *cbc_buffer);
+
+static int cbc_device_open(struct inode *, struct file *);
+static int cbc_device_release(struct inode *, struct file *);
+static ssize_t cbc_device_read(struct file *, char __user *, size_t,
+ loff_t *);
+static ssize_t cbc_device_write(struct file *, const char __user *, size_t,
+ loff_t *);
+static unsigned int cbc_device_poll(struct file *file, poll_table *wait);
+static long cbc_device_ioctl(struct file *, unsigned int, unsigned long);
+
+static const struct file_operations cbc_dev_file_operations = {
+ .owner = THIS_MODULE,
+ .open = cbc_device_open,
+ .release = cbc_device_release,
+ .read = cbc_device_read,
+ .write = cbc_device_write,
+ .poll = cbc_device_poll,
+ .unlocked_ioctl = cbc_device_ioctl
+};
+
+struct cbc_device_manager {
+ struct cdev cdev;
+ struct cbc_device_data channels[CBC_CHANNEL_MAX_NUMBER];
+ struct mutex send_lock;
+ struct cbc_memory_pool *cbc_memory;
+};
+
+/* Currently, only one CBC per kernel supported.*/
+static struct cbc_device_manager cbc_device_mgr_configuration = {
+ .channels[CBC_CHANNEL_PMT].device_type =
+ CBC_DEVICE_TYPE_HIDDEN,
+ .channels[CBC_CHANNEL_PMT].device_name =
+ "cbc-pmt",
+
+ .channels[CBC_CHANNEL_LIFECYCLE].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_LIFECYCLE].device_name =
+ "cbc-lifecycle",
+
+ .channels[CBC_CHANNEL_SIGNALS].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_SIGNALS].device_name =
+ "cbc-signals",
+
+ .channels[CBC_CHANNEL_EARLY_SIGNALS].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_EARLY_SIGNALS].device_name =
+ "cbc-early-signals",
+
+ .channels[CBC_CHANNEL_DIAGNOSIS].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_DIAGNOSIS].device_name =
+ "cbc-diagnosis",
+
+ .channels[CBC_CHANNEL_DLT].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_DLT].device_name =
+ "cbc-dlt",
+
+ .channels[CBC_CHANNEL_LINDA].device_type =
+ CBC_DEVICE_TYPE_HIDDEN,
+ .channels[CBC_CHANNEL_LINDA].device_name =
+ "cbc-linda",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_0].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_0].device_name =
+ "cbc-raw0",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_1].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_1].device_name =
+ "cbc-raw1",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_2].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_2].device_name =
+ "cbc-raw2",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_3].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_3].device_name =
+ "cbc-raw3",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_4].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_4].device_name =
+ "cbc-raw4",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_5].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_5].device_name =
+ "cbc-raw5",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_6].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_6].device_name =
+ "cbc-raw6",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_7].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_7].device_name =
+ "cbc-raw7",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_8].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_8].device_name =
+ "cbc-raw8",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_9].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_9].device_name =
+ "cbc-raw9",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_10].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_10].device_name =
+ "cbc-raw10",
+
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_11].device_type =
+ CBC_DEVICE_TYPE_DEFAULT,
+ .channels[CBC_CHANNEL_OEM_RAW_CHANNEL_11].device_name =
+ "cbc-raw11",
+
+ .channels[CBC_CHANNEL_DEBUG_OUT].device_type =
+ CBC_DEVICE_TYPE_DEBUG,
+ .channels[CBC_CHANNEL_DEBUG_OUT].device_name =
+ "cbc-debug-out",
+
+ .channels[CBC_CHANNEL_DEBUG_IN].device_type =
+ CBC_DEVICE_TYPE_DEBUG,
+ .channels[CBC_CHANNEL_DEBUG_IN].device_name =
+ "cbc-debug-in",
+};
+
+static struct cbc_mux_channel_configuration cbc_mux_config;
+
+/*
+ * priority_show - Retrieve device attribute priority.
+ * @dev: device (i.e /dev/cbc*)
+ * @attr: Priority attribute
+ * @buf: Buffer to write to.
+ *
+ * Every channel (entry in /dev) has a priority.
+ * This can be set/read by a ioctl or in the sysfs.
+ */
+static ssize_t priority_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cbc_device_data *chn_data =
+ (struct cbc_device_data *) dev_get_drvdata(dev);
+ int idx = chn_data - &cbc_device_mgr_configuration.channels[0];
+ int prio = cbc_mux_multiplexer_get_priority(idx);
+
+ pr_debug("cbc-core: read priority %i for channel: %i\n", prio, idx);
+ return scnprintf(buf, PAGE_SIZE, "%i\n", prio);
+}
+
+/*
+ * priority_store - Store device attribute priority.
+ * @dev: device (i.e /dev/cbc*)
+ * @attr: Priority attribute
+ * @buf: Buffer to write to.
+ *
+ * Every channel (entry in /dev) has a priority.
+ * This can be set/read by a ioctl or in the sysfs.
+ */
+static ssize_t priority_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct cbc_device_data *chn_data =
+ (struct cbc_device_data *) dev_get_drvdata(dev);
+ int idx = chn_data - &cbc_device_mgr_configuration.channels[0];
+ u8 tmp = 0;
+ int res = kstrtou8(buf, 0, &tmp);
+
+ if ((res == 0) && (tmp < 8)) {
+ pr_debug("cbc-core: write priority %i to channel %i\n", tmp,
+ idx);
+ cbc_mux_multiplexer_set_priority(idx, tmp);
+ }
+ return count;
+}
+static DEVICE_ATTR_RW(priority);
+
+/*
+ * cbc_device_open - Open CBC char device. Implementation of .open.
+ * @inode:Pointer to inode object for this device.
+ * @file: Pointer to file object for this device.
+ *
+ * Return 0 if device opened successfully, Linux error code otherwise.
+ */
+static int cbc_device_open(struct inode *inode, struct file *file)
+{
+ struct cbc_device_data *device_data =
+ &cbc_device_mgr_configuration.channels[MINOR(
+ inode->i_rdev)];
+ int ret = 0;
+ u32 num_open_files = 0;
+ struct cbc_file_data *file_data = kmalloc(sizeof(struct cbc_file_data),
+ GFP_KERNEL);
+
+ if (!device_data)
+ ret = -EIO;
+
+ if (!file_data)
+ ret = -ENOMEM;
+
+ if (ret == 0) {
+ pr_debug("cbc_core: device_open: %d.%d %s\n",
+ MAJOR(inode->i_rdev), MINOR(inode->i_rdev),
+ device_data->device_name);
+
+ if (MINOR(inode->i_rdev) >= CBC_CHANNEL_MAX_NUMBER) {
+ pr_err("cbc-core: invalid cbc channel number.\n");
+ ret = -ENODEV;
+ }
+ }
+
+ if (ret == 0) {
+ struct list_head *tmp;
+
+ list_for_each(tmp, &device_data->open_files_head)
+ num_open_files++;
+
+ if (num_open_files > MAX_OPEN_FILES)
+ ret = -EBUSY;
+ }
+
+ if (ret == 0) {
+ cbc_file_init(file_data);
+ file_data->cbc_device = device_data;
+ list_add(&file_data->list, &device_data->open_files_head);
+ file->private_data = file_data;
+ } else {
+ kfree(file_data);
+ }
+
+ return ret;
+}
+
+/*