linux/drivers/hsi/clients/hsi_char.c
Thomas Gleixner 2b27bdcc20 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336
Based on 1 normalized pattern(s):

  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 this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 246 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:07 +02:00

789 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* HSI character device driver, implements the character device
* interface.
*
* Copyright (C) 2010 Nokia Corporation. All rights reserved.
*
* Contact: Andras Domokos <andras.domokos@nokia.com>
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/kmemleak.h>
#include <linux/ioctl.h>
#include <linux/wait.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/scatterlist.h>
#include <linux/stat.h>
#include <linux/hsi/hsi.h>
#include <linux/hsi/hsi_char.h>
#define HSC_DEVS 16 /* Num of channels */
#define HSC_MSGS 4
#define HSC_RXBREAK 0
#define HSC_ID_BITS 6
#define HSC_PORT_ID_BITS 4
#define HSC_ID_MASK 3
#define HSC_PORT_ID_MASK 3
#define HSC_CH_MASK 0xf
/*
* We support up to 4 controllers that can have up to 4
* ports, which should currently be more than enough.
*/
#define HSC_BASEMINOR(id, port_id) \
((((id) & HSC_ID_MASK) << HSC_ID_BITS) | \
(((port_id) & HSC_PORT_ID_MASK) << HSC_PORT_ID_BITS))
enum {
HSC_CH_OPEN,
HSC_CH_READ,
HSC_CH_WRITE,
HSC_CH_WLINE,
};
enum {
HSC_RX,
HSC_TX,
};
struct hsc_client_data;
/**
* struct hsc_channel - hsi_char internal channel data
* @ch: channel number
* @flags: Keeps state of the channel (open/close, reading, writing)
* @free_msgs_list: List of free HSI messages/requests
* @rx_msgs_queue: List of pending RX requests
* @tx_msgs_queue: List of pending TX requests
* @lock: Serialize access to the lists
* @cl: reference to the associated hsi_client
* @cl_data: reference to the client data that this channels belongs to
* @rx_wait: RX requests wait queue
* @tx_wait: TX requests wait queue
*/
struct hsc_channel {
unsigned int ch;
unsigned long flags;
struct list_head free_msgs_list;
struct list_head rx_msgs_queue;
struct list_head tx_msgs_queue;
spinlock_t lock;
struct hsi_client *cl;
struct hsc_client_data *cl_data;
wait_queue_head_t rx_wait;
wait_queue_head_t tx_wait;
};
/**
* struct hsc_client_data - hsi_char internal client data
* @cdev: Characther device associated to the hsi_client
* @lock: Lock to serialize open/close access
* @flags: Keeps track of port state (rx hwbreak armed)
* @usecnt: Use count for claiming the HSI port (mutex protected)
* @cl: Referece to the HSI client
* @channels: Array of channels accessible by the client
*/
struct hsc_client_data {
struct cdev cdev;
struct mutex lock;
unsigned long flags;
unsigned int usecnt;
struct hsi_client *cl;
struct hsc_channel channels[HSC_DEVS];
};
/* Stores the major number dynamically allocated for hsi_char */
static unsigned int hsc_major;
/* Maximum buffer size that hsi_char will accept from userspace */
static unsigned int max_data_size = 0x1000;
module_param(max_data_size, uint, 0);
MODULE_PARM_DESC(max_data_size, "max read/write data size [4,8..65536] (^2)");
static void hsc_add_tail(struct hsc_channel *channel, struct hsi_msg *msg,
struct list_head *queue)
{
unsigned long flags;
spin_lock_irqsave(&channel->lock, flags);
list_add_tail(&msg->link, queue);
spin_unlock_irqrestore(&channel->lock, flags);
}
static struct hsi_msg *hsc_get_first_msg(struct hsc_channel *channel,
struct list_head *queue)
{
struct hsi_msg *msg = NULL;
unsigned long flags;
spin_lock_irqsave(&channel->lock, flags);
if (list_empty(queue))
goto out;
msg = list_first_entry(queue, struct hsi_msg, link);
list_del(&msg->link);
out:
spin_unlock_irqrestore(&channel->lock, flags);
return msg;
}
static inline void hsc_msg_free(struct hsi_msg *msg)
{
kfree(sg_virt(msg->sgt.sgl));
hsi_free_msg(msg);
}
static void hsc_free_list(struct list_head *list)
{
struct hsi_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, list, link) {
list_del(&msg->link);
hsc_msg_free(msg);
}
}
static void hsc_reset_list(struct hsc_channel *channel, struct list_head *l)
{
unsigned long flags;
LIST_HEAD(list);
spin_lock_irqsave(&channel->lock, flags);
list_splice_init(l, &list);
spin_unlock_irqrestore(&channel->lock, flags);
hsc_free_list(&list);
}
static inline struct hsi_msg *hsc_msg_alloc(unsigned int alloc_size)
{
struct hsi_msg *msg;
void *buf;
msg = hsi_alloc_msg(1, GFP_KERNEL);
if (!msg)
goto out;
buf = kmalloc(alloc_size, GFP_KERNEL);
if (!buf) {
hsi_free_msg(msg);
goto out;
}
sg_init_one(msg->sgt.sgl, buf, alloc_size);
/* Ignore false positive, due to sg pointer handling */
kmemleak_ignore(buf);
return msg;
out:
return NULL;
}
static inline int hsc_msgs_alloc(struct hsc_channel *channel)
{
struct hsi_msg *msg;
int i;
for (i = 0; i < HSC_MSGS; i++) {
msg = hsc_msg_alloc(max_data_size);
if (!msg)
goto out;
msg->channel = channel->ch;
list_add_tail(&msg->link, &channel->free_msgs_list);
}
return 0;
out:
hsc_free_list(&channel->free_msgs_list);
return -ENOMEM;
}
static inline unsigned int hsc_msg_len_get(struct hsi_msg *msg)
{
return msg->sgt.sgl->length;
}
static inline void hsc_msg_len_set(struct hsi_msg *msg, unsigned int len)
{
msg->sgt.sgl->length = len;
}
static void hsc_rx_completed(struct hsi_msg *msg)
{
struct hsc_client_data *cl_data = hsi_client_drvdata(msg->cl);
struct hsc_channel *channel = cl_data->channels + msg->channel;
if (test_bit(HSC_CH_READ, &channel->flags)) {
hsc_add_tail(channel, msg, &channel->rx_msgs_queue);
wake_up(&channel->rx_wait);
} else {
hsc_add_tail(channel, msg, &channel->free_msgs_list);
}
}
static void hsc_rx_msg_destructor(struct hsi_msg *msg)
{
msg->status = HSI_STATUS_ERROR;
hsc_msg_len_set(msg, 0);
hsc_rx_completed(msg);
}
static void hsc_tx_completed(struct hsi_msg *msg)
{
struct hsc_client_data *cl_data = hsi_client_drvdata(msg->cl);
struct hsc_channel *channel = cl_data->channels + msg->channel;
if (test_bit(HSC_CH_WRITE, &channel->flags)) {
hsc_add_tail(channel, msg, &channel->tx_msgs_queue);
wake_up(&channel->tx_wait);
} else {
hsc_add_tail(channel, msg, &channel->free_msgs_list);
}
}
static void hsc_tx_msg_destructor(struct hsi_msg *msg)
{
msg->status = HSI_STATUS_ERROR;
hsc_msg_len_set(msg, 0);
hsc_tx_completed(msg);
}
static void hsc_break_req_destructor(struct hsi_msg *msg)
{
struct hsc_client_data *cl_data = hsi_client_drvdata(msg->cl);
hsi_free_msg(msg);
clear_bit(HSC_RXBREAK, &cl_data->flags);
}
static void hsc_break_received(struct hsi_msg *msg)
{
struct hsc_client_data *cl_data = hsi_client_drvdata(msg->cl);
struct hsc_channel *channel = cl_data->channels;
int i, ret;
/* Broadcast HWBREAK on all channels */
for (i = 0; i < HSC_DEVS; i++, channel++) {
struct hsi_msg *msg2;
if (!test_bit(HSC_CH_READ, &channel->flags))
continue;
msg2 = hsc_get_first_msg(channel, &channel->free_msgs_list);
if (!msg2)
continue;
clear_bit(HSC_CH_READ, &channel->flags);
hsc_msg_len_set(msg2, 0);
msg2->status = HSI_STATUS_COMPLETED;
hsc_add_tail(channel, msg2, &channel->rx_msgs_queue);
wake_up(&channel->rx_wait);
}
hsi_flush(msg->cl);
ret = hsi_async_read(msg->cl, msg);
if (ret < 0)
hsc_break_req_destructor(msg);
}
static int hsc_break_request(struct hsi_client *cl)
{
struct hsc_client_data *cl_data = hsi_client_drvdata(cl);
struct hsi_msg *msg;
int ret;
if (test_and_set_bit(HSC_RXBREAK, &cl_data->flags))
return -EBUSY;
msg = hsi_alloc_msg(0, GFP_KERNEL);
if (!msg) {
clear_bit(HSC_RXBREAK, &cl_data->flags);
return -ENOMEM;
}
msg->break_frame = 1;
msg->complete = hsc_break_received;
msg->destructor = hsc_break_req_destructor;
ret = hsi_async_read(cl, msg);
if (ret < 0)
hsc_break_req_destructor(msg);
return ret;
}
static int hsc_break_send(struct hsi_client *cl)
{
struct hsi_msg *msg;
int ret;
msg = hsi_alloc_msg(0, GFP_ATOMIC);
if (!msg)
return -ENOMEM;
msg->break_frame = 1;
msg->complete = hsi_free_msg;
msg->destructor = hsi_free_msg;
ret = hsi_async_write(cl, msg);
if (ret < 0)
hsi_free_msg(msg);
return ret;
}
static int hsc_rx_set(struct hsi_client *cl, struct hsc_rx_config *rxc)
{
struct hsi_config tmp;
int ret;
if ((rxc->mode != HSI_MODE_STREAM) && (rxc->mode != HSI_MODE_FRAME))
return -EINVAL;
if ((rxc->channels == 0) || (rxc->channels > HSC_DEVS))
return -EINVAL;
if (rxc->channels & (rxc->channels - 1))
return -EINVAL;
if ((rxc->flow != HSI_FLOW_SYNC) && (rxc->flow != HSI_FLOW_PIPE))
return -EINVAL;
tmp = cl->rx_cfg;
cl->rx_cfg.mode = rxc->mode;
cl->rx_cfg.num_hw_channels = rxc->channels;
cl->rx_cfg.flow = rxc->flow;
ret = hsi_setup(cl);
if (ret < 0) {
cl->rx_cfg = tmp;
return ret;
}
if (rxc->mode == HSI_MODE_FRAME)
hsc_break_request(cl);
return ret;
}
static inline void hsc_rx_get(struct hsi_client *cl, struct hsc_rx_config *rxc)
{
rxc->mode = cl->rx_cfg.mode;
rxc->channels = cl->rx_cfg.num_hw_channels;
rxc->flow = cl->rx_cfg.flow;
}
static int hsc_tx_set(struct hsi_client *cl, struct hsc_tx_config *txc)
{
struct hsi_config tmp;
int ret;
if ((txc->mode != HSI_MODE_STREAM) && (txc->mode != HSI_MODE_FRAME))
return -EINVAL;
if ((txc->channels == 0) || (txc->channels > HSC_DEVS))
return -EINVAL;
if (txc->channels & (txc->channels - 1))
return -EINVAL;
if ((txc->arb_mode != HSI_ARB_RR) && (txc->arb_mode != HSI_ARB_PRIO))
return -EINVAL;
tmp = cl->tx_cfg;
cl->tx_cfg.mode = txc->mode;
cl->tx_cfg.num_hw_channels = txc->channels;
cl->tx_cfg.speed = txc->speed;
cl->tx_cfg.arb_mode = txc->arb_mode;
ret = hsi_setup(cl);
if (ret < 0) {
cl->tx_cfg = tmp;
return ret;
}
return ret;
}
static inline void hsc_tx_get(struct hsi_client *cl, struct hsc_tx_config *txc)
{
txc->mode = cl->tx_cfg.mode;
txc->channels = cl->tx_cfg.num_hw_channels;
txc->speed = cl->tx_cfg.speed;
txc->arb_mode = cl->tx_cfg.arb_mode;
}
static ssize_t hsc_read(struct file *file, char __user *buf, size_t len,
loff_t *ppos __maybe_unused)
{
struct hsc_channel *channel = file->private_data;
struct hsi_msg *msg;
ssize_t ret;
if (len == 0)
return 0;
if (!IS_ALIGNED(len, sizeof(u32)))
return -EINVAL;
if (len > max_data_size)
len = max_data_size;
if (channel->ch >= channel->cl->rx_cfg.num_hw_channels)
return -ECHRNG;
if (test_and_set_bit(HSC_CH_READ, &channel->flags))
return -EBUSY;
msg = hsc_get_first_msg(channel, &channel->free_msgs_list);
if (!msg) {
ret = -ENOSPC;
goto out;
}
hsc_msg_len_set(msg, len);
msg->complete = hsc_rx_completed;
msg->destructor = hsc_rx_msg_destructor;
ret = hsi_async_read(channel->cl, msg);
if (ret < 0) {
hsc_add_tail(channel, msg, &channel->free_msgs_list);
goto out;
}
ret = wait_event_interruptible(channel->rx_wait,
!list_empty(&channel->rx_msgs_queue));
if (ret < 0) {
clear_bit(HSC_CH_READ, &channel->flags);
hsi_flush(channel->cl);
return -EINTR;
}
msg = hsc_get_first_msg(channel, &channel->rx_msgs_queue);
if (msg) {
if (msg->status != HSI_STATUS_ERROR) {
ret = copy_to_user((void __user *)buf,
sg_virt(msg->sgt.sgl), hsc_msg_len_get(msg));
if (ret)
ret = -EFAULT;
else
ret = hsc_msg_len_get(msg);
} else {
ret = -EIO;
}
hsc_add_tail(channel, msg, &channel->free_msgs_list);
}
out:
clear_bit(HSC_CH_READ, &channel->flags);
return ret;
}
static ssize_t hsc_write(struct file *file, const char __user *buf, size_t len,
loff_t *ppos __maybe_unused)
{
struct hsc_channel *channel = file->private_data;
struct hsi_msg *msg;
ssize_t ret;
if ((len == 0) || !IS_ALIGNED(len, sizeof(u32)))
return -EINVAL;
if (len > max_data_size)
len = max_data_size;
if (channel->ch >= channel->cl->tx_cfg.num_hw_channels)
return -ECHRNG;
if (test_and_set_bit(HSC_CH_WRITE, &channel->flags))
return -EBUSY;
msg = hsc_get_first_msg(channel, &channel->free_msgs_list);
if (!msg) {
clear_bit(HSC_CH_WRITE, &channel->flags);
return -ENOSPC;
}
if (copy_from_user(sg_virt(msg->sgt.sgl), (void __user *)buf, len)) {
ret = -EFAULT;
goto out;
}
hsc_msg_len_set(msg, len);
msg->complete = hsc_tx_completed;
msg->destructor = hsc_tx_msg_destructor;
ret = hsi_async_write(channel->cl, msg);
if (ret < 0)
goto out;
ret = wait_event_interruptible(channel->tx_wait,
!list_empty(&channel->tx_msgs_queue));
if (ret < 0) {
clear_bit(HSC_CH_WRITE, &channel->flags);
hsi_flush(channel->cl);
return -EINTR;
}
msg = hsc_get_first_msg(channel, &channel->tx_msgs_queue);
if (msg) {
if (msg->status == HSI_STATUS_ERROR)
ret = -EIO;
else
ret = hsc_msg_len_get(msg);
hsc_add_tail(channel, msg, &channel->free_msgs_list);
}
out:
clear_bit(HSC_CH_WRITE, &channel->flags);
return ret;
}
static long hsc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct hsc_channel *channel = file->private_data;
unsigned int state;
struct hsc_rx_config rxc;
struct hsc_tx_config txc;
long ret = 0;
switch (cmd) {
case HSC_RESET:
hsi_flush(channel->cl);
break;
case HSC_SET_PM:
if (copy_from_user(&state, (void __user *)arg, sizeof(state)))
return -EFAULT;
if (state == HSC_PM_DISABLE) {
if (test_and_set_bit(HSC_CH_WLINE, &channel->flags))
return -EINVAL;
ret = hsi_start_tx(channel->cl);
} else if (state == HSC_PM_ENABLE) {
if (!test_and_clear_bit(HSC_CH_WLINE, &channel->flags))
return -EINVAL;
ret = hsi_stop_tx(channel->cl);
} else {
ret = -EINVAL;
}
break;
case HSC_SEND_BREAK:
return hsc_break_send(channel->cl);
case HSC_SET_RX:
if (copy_from_user(&rxc, (void __user *)arg, sizeof(rxc)))
return -EFAULT;
return hsc_rx_set(channel->cl, &rxc);
case HSC_GET_RX:
hsc_rx_get(channel->cl, &rxc);
if (copy_to_user((void __user *)arg, &rxc, sizeof(rxc)))
return -EFAULT;
break;
case HSC_SET_TX:
if (copy_from_user(&txc, (void __user *)arg, sizeof(txc)))
return -EFAULT;
return hsc_tx_set(channel->cl, &txc);
case HSC_GET_TX:
hsc_tx_get(channel->cl, &txc);
if (copy_to_user((void __user *)arg, &txc, sizeof(txc)))
return -EFAULT;
break;
default:
return -ENOIOCTLCMD;
}
return ret;
}
static inline void __hsc_port_release(struct hsc_client_data *cl_data)
{
BUG_ON(cl_data->usecnt == 0);
if (--cl_data->usecnt == 0) {
hsi_flush(cl_data->cl);
hsi_release_port(cl_data->cl);
}
}
static int hsc_open(struct inode *inode, struct file *file)
{
struct hsc_client_data *cl_data;
struct hsc_channel *channel;
int ret = 0;
pr_debug("open, minor = %d\n", iminor(inode));
cl_data = container_of(inode->i_cdev, struct hsc_client_data, cdev);
mutex_lock(&cl_data->lock);
channel = cl_data->channels + (iminor(inode) & HSC_CH_MASK);
if (test_and_set_bit(HSC_CH_OPEN, &channel->flags)) {
ret = -EBUSY;
goto out;
}
/*
* Check if we have already claimed the port associated to the HSI
* client. If not then try to claim it, else increase its refcount
*/
if (cl_data->usecnt == 0) {
ret = hsi_claim_port(cl_data->cl, 0);
if (ret < 0)
goto out;
hsi_setup(cl_data->cl);
}
cl_data->usecnt++;
ret = hsc_msgs_alloc(channel);
if (ret < 0) {
__hsc_port_release(cl_data);
goto out;
}
file->private_data = channel;
mutex_unlock(&cl_data->lock);
return ret;
out:
mutex_unlock(&cl_data->lock);
return ret;
}
static int hsc_release(struct inode *inode __maybe_unused, struct file *file)
{
struct hsc_channel *channel = file->private_data;
struct hsc_client_data *cl_data = channel->cl_data;
mutex_lock(&cl_data->lock);
file->private_data = NULL;
if (test_and_clear_bit(HSC_CH_WLINE, &channel->flags))
hsi_stop_tx(channel->cl);
__hsc_port_release(cl_data);
hsc_reset_list(channel, &channel->rx_msgs_queue);
hsc_reset_list(channel, &channel->tx_msgs_queue);
hsc_reset_list(channel, &channel->free_msgs_list);
clear_bit(HSC_CH_READ, &channel->flags);
clear_bit(HSC_CH_WRITE, &channel->flags);
clear_bit(HSC_CH_OPEN, &channel->flags);
wake_up(&channel->rx_wait);
wake_up(&channel->tx_wait);
mutex_unlock(&cl_data->lock);
return 0;
}
static const struct file_operations hsc_fops = {
.owner = THIS_MODULE,
.read = hsc_read,
.write = hsc_write,
.unlocked_ioctl = hsc_ioctl,
.open = hsc_open,
.release = hsc_release,
};
static void hsc_channel_init(struct hsc_channel *channel)
{
init_waitqueue_head(&channel->rx_wait);
init_waitqueue_head(&channel->tx_wait);
spin_lock_init(&channel->lock);
INIT_LIST_HEAD(&channel->free_msgs_list);
INIT_LIST_HEAD(&channel->rx_msgs_queue);
INIT_LIST_HEAD(&channel->tx_msgs_queue);
}
static int hsc_probe(struct device *dev)
{
const char devname[] = "hsi_char";
struct hsc_client_data *cl_data;
struct hsc_channel *channel;
struct hsi_client *cl = to_hsi_client(dev);
unsigned int hsc_baseminor;
dev_t hsc_dev;
int ret;
int i;
cl_data = kzalloc(sizeof(*cl_data), GFP_KERNEL);
if (!cl_data)
return -ENOMEM;
hsc_baseminor = HSC_BASEMINOR(hsi_id(cl), hsi_port_id(cl));
if (!hsc_major) {
ret = alloc_chrdev_region(&hsc_dev, hsc_baseminor,
HSC_DEVS, devname);
if (ret == 0)
hsc_major = MAJOR(hsc_dev);
} else {
hsc_dev = MKDEV(hsc_major, hsc_baseminor);
ret = register_chrdev_region(hsc_dev, HSC_DEVS, devname);
}
if (ret < 0) {
dev_err(dev, "Device %s allocation failed %d\n",
hsc_major ? "minor" : "major", ret);
goto out1;
}
mutex_init(&cl_data->lock);
hsi_client_set_drvdata(cl, cl_data);
cdev_init(&cl_data->cdev, &hsc_fops);
cl_data->cdev.owner = THIS_MODULE;
cl_data->cl = cl;
for (i = 0, channel = cl_data->channels; i < HSC_DEVS; i++, channel++) {
hsc_channel_init(channel);
channel->ch = i;
channel->cl = cl;
channel->cl_data = cl_data;
}
/* 1 hsi client -> N char devices (one for each channel) */
ret = cdev_add(&cl_data->cdev, hsc_dev, HSC_DEVS);
if (ret) {
dev_err(dev, "Could not add char device %d\n", ret);
goto out2;
}
return 0;
out2:
unregister_chrdev_region(hsc_dev, HSC_DEVS);
out1:
kfree(cl_data);
return ret;
}
static int hsc_remove(struct device *dev)
{
struct hsi_client *cl = to_hsi_client(dev);
struct hsc_client_data *cl_data = hsi_client_drvdata(cl);
dev_t hsc_dev = cl_data->cdev.dev;
cdev_del(&cl_data->cdev);
unregister_chrdev_region(hsc_dev, HSC_DEVS);
hsi_client_set_drvdata(cl, NULL);
kfree(cl_data);
return 0;
}
static struct hsi_client_driver hsc_driver = {
.driver = {
.name = "hsi_char",
.owner = THIS_MODULE,
.probe = hsc_probe,
.remove = hsc_remove,
},
};
static int __init hsc_init(void)
{
int ret;
if ((max_data_size < 4) || (max_data_size > 0x10000) ||
(max_data_size & (max_data_size - 1))) {
pr_err("Invalid max read/write data size\n");
return -EINVAL;
}
ret = hsi_register_client_driver(&hsc_driver);
if (ret) {
pr_err("Error while registering HSI/SSI driver %d\n", ret);
return ret;
}
pr_info("HSI/SSI char device loaded\n");
return 0;
}
module_init(hsc_init);
static void __exit hsc_exit(void)
{
hsi_unregister_client_driver(&hsc_driver);
pr_info("HSI char device removed\n");
}
module_exit(hsc_exit);
MODULE_AUTHOR("Andras Domokos <andras.domokos@nokia.com>");
MODULE_ALIAS("hsi:hsi_char");
MODULE_DESCRIPTION("HSI character device");
MODULE_LICENSE("GPL v2");