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    Subject[RFC PATCHv5 4/7] HSI: hsi_char: Add HSI char device driver
    Date
    From: Andras Domokos <andras.domokos@nokia.com>

    Add HSI char device driver to the kernel.

    Signed-off-by: Andras Domokos <andras.domokos@nokia.com>
    Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
    Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
    ---
    drivers/hsi/clients/hsi_char.c | 804 ++++++++++++++++++++++++++++++++++++++++
    include/linux/hsi/hsi_char.h | 65 ++++
    2 files changed, 869 insertions(+), 0 deletions(-)
    create mode 100644 drivers/hsi/clients/hsi_char.c
    create mode 100644 include/linux/hsi/hsi_char.h

    diff --git a/drivers/hsi/clients/hsi_char.c b/drivers/hsi/clients/hsi_char.c
    new file mode 100644
    index 0000000..ad56bfd
    --- /dev/null
    +++ b/drivers/hsi/clients/hsi_char.c
    @@ -0,0 +1,804 @@
    +/*
    + * hsi-char.c
    + *
    + * HSI character device driver, implements the character device
    + * interface.
    + *
    + * Copyright (C) 2010 Nokia Corporation. All rights reserved.
    + *
    + * Contact: Andras Domokos <andras.domokos@nokia.com>
    + *
    + * 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
    + */
    +
    +#include <linux/errno.h>
    +#include <linux/types.h>
    +#include <linux/atomic.h>
    +#include <linux/kernel.h>
    +#include <linux/kmemleak.h>
    +#include <linux/init.h>
    +#include <linux/module.h>
    +#include <linux/mutex.h>
    +#include <linux/list.h>
    +#include <linux/slab.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, S_IRUSR | S_IWUSR);
    +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.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.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.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.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.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.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 __devinit 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 __devinit 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) {
    + dev_err(dev, "Could not allocate hsc_client_data\n");
    + 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 __devexit 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 = __devexit_p(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");
    + return -EINVAL;
    + }
    +
    + ret = hsi_register_client_driver(&hsc_driver);
    + if (ret) {
    + pr_err("Error while registering HSI/SSI driver %d", 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");
    diff --git a/include/linux/hsi/hsi_char.h b/include/linux/hsi/hsi_char.h
    new file mode 100644
    index 0000000..fc49897
    --- /dev/null
    +++ b/include/linux/hsi/hsi_char.h
    @@ -0,0 +1,65 @@
    +/*
    + * hsi_char.h
    + *
    + * Part of the HSI character device driver.
    + *
    + * Copyright (C) 2010 Nokia Corporation. All rights reserved.
    + *
    + * Contact: Andras Domokos <andras.domokos at nokia.com>
    + *
    + * 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
    + */
    +
    +
    +#ifndef __HSI_CHAR_H
    +#define __HSI_CHAR_H
    +
    +#define HSI_CHAR_MAGIC 'k'
    +#define HSC_IOW(num, dtype) _IOW(HSI_CHAR_MAGIC, num, dtype)
    +#define HSC_IOR(num, dtype) _IOR(HSI_CHAR_MAGIC, num, dtype)
    +#define HSC_IOWR(num, dtype) _IOWR(HSI_CHAR_MAGIC, num, dtype)
    +#define HSC_IO(num) _IO(HSI_CHAR_MAGIC, num)
    +
    +#define HSC_RESET HSC_IO(16)
    +#define HSC_SET_PM HSC_IO(17)
    +#define HSC_SEND_BREAK HSC_IO(18)
    +#define HSC_SET_RX HSC_IOW(19, struct hsc_rx_config)
    +#define HSC_GET_RX HSC_IOW(20, struct hsc_rx_config)
    +#define HSC_SET_TX HSC_IOW(21, struct hsc_tx_config)
    +#define HSC_GET_TX HSC_IOW(22, struct hsc_tx_config)
    +
    +#define HSC_PM_DISABLE 0
    +#define HSC_PM_ENABLE 1
    +
    +#define HSC_MODE_STREAM 1
    +#define HSC_MODE_FRAME 2
    +#define HSC_FLOW_SYNC 0
    +#define HSC_ARB_RR 0
    +#define HSC_ARB_PRIO 1
    +
    +struct hsc_rx_config {
    + uint32_t mode;
    + uint32_t flow;
    + uint32_t channels;
    +};
    +
    +struct hsc_tx_config {
    + uint32_t mode;
    + uint32_t channels;
    + uint32_t speed;
    + uint32_t arb_mode;
    +};
    +
    +#endif /* __HSI_CHAR_H */
    --
    1.7.1


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