diff --git a/drivers/staging/most/Kconfig b/drivers/staging/most/Kconfig index b7db320dbacc..e29bee569c77 100644 --- a/drivers/staging/most/Kconfig +++ b/drivers/staging/most/Kconfig @@ -13,4 +13,6 @@ if MOST source "drivers/staging/most/mostcore/Kconfig" +source "drivers/staging/most/aim-cdev/Kconfig" + endif diff --git a/drivers/staging/most/Makefile b/drivers/staging/most/Makefile index 0144be009337..b7b319bd61a1 100644 --- a/drivers/staging/most/Makefile +++ b/drivers/staging/most/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_MOSTCORE) += mostcore/ +obj-$(CONFIG_AIM_CDEV) += aim-cdev/ diff --git a/drivers/staging/most/aim-cdev/Kconfig b/drivers/staging/most/aim-cdev/Kconfig new file mode 100644 index 000000000000..3c59f1bac127 --- /dev/null +++ b/drivers/staging/most/aim-cdev/Kconfig @@ -0,0 +1,12 @@ +# +# MOST Cdev configuration +# + +config AIM_CDEV + tristate "Cdev AIM" + + ---help--- + Say Y here if you want to commumicate via character devices. + + To compile this driver as a module, choose M here: the + module will be called aim_cdev. \ No newline at end of file diff --git a/drivers/staging/most/aim-cdev/Makefile b/drivers/staging/most/aim-cdev/Makefile new file mode 100644 index 000000000000..0bcc6c637b75 --- /dev/null +++ b/drivers/staging/most/aim-cdev/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_AIM_CDEV) += aim_cdev.o + +aim_cdev-objs := cdev.o +ccflags-y += -Idrivers/staging/most/mostcore/ \ No newline at end of file diff --git a/drivers/staging/most/aim-cdev/cdev.c b/drivers/staging/most/aim-cdev/cdev.c new file mode 100644 index 000000000000..d5fb4a0e0818 --- /dev/null +++ b/drivers/staging/most/aim-cdev/cdev.c @@ -0,0 +1,527 @@ +/* + * cdev.c - Application interfacing module for character devices + * + * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG + * + * 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. + * + * This file is licensed under GPLv2. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "mostcore.h" + +static dev_t aim_devno; +static struct class *aim_class; +static struct ida minor_id; +static unsigned int major; + +struct aim_channel { + wait_queue_head_t wq; + struct cdev cdev; + struct device *dev; + struct mutex io_mutex; + struct most_interface *iface; + struct most_channel_config *cfg; + unsigned int channel_id; + dev_t devno; + bool keep_mbo; + unsigned int mbo_offs; + struct mbo *stacked_mbo; + DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *)); + atomic_t access_ref; + struct list_head list; +}; +#define to_channel(d) container_of(d, struct aim_channel, cdev) +static struct list_head channel_list; +static spinlock_t ch_list_lock; + + +struct aim_channel *get_channel(struct most_interface *iface, int id) +{ + struct aim_channel *channel, *tmp; + unsigned long flags; + int found_channel = 0; + + spin_lock_irqsave(&ch_list_lock, flags); + list_for_each_entry_safe(channel, tmp, &channel_list, list) { + if ((channel->iface == iface) && (channel->channel_id == id)) { + found_channel = 1; + break; + } + } + spin_unlock_irqrestore(&ch_list_lock, flags); + if (!found_channel) + return NULL; + return channel; +} + +/** + * aim_open - implements the syscall to open the device + * @inode: inode pointer + * @filp: file pointer + * + * This stores the channel pointer in the private data field of + * the file structure and activates the channel within the core. + */ +static int aim_open(struct inode *inode, struct file *filp) +{ + struct aim_channel *channel; + int ret; + + channel = to_channel(inode->i_cdev); + filp->private_data = channel; + + if (((channel->cfg->direction == MOST_CH_RX) && + ((filp->f_flags & O_ACCMODE) != O_RDONLY)) + || ((channel->cfg->direction == MOST_CH_TX) && + ((filp->f_flags & O_ACCMODE) != O_WRONLY))) { + pr_info("WARN: Access flags mismatch\n"); + return -EACCES; + } + if (!atomic_inc_and_test(&channel->access_ref)) { + pr_info("WARN: Device is busy\n"); + atomic_dec(&channel->access_ref); + return -EBUSY; + } + + ret = most_start_channel(channel->iface, channel->channel_id); + if (ret) + atomic_dec(&channel->access_ref); + return ret; +} + +/** + * aim_close - implements the syscall to close the device + * @inode: inode pointer + * @filp: file pointer + * + * This stops the channel within the core. + */ +static int aim_close(struct inode *inode, struct file *filp) +{ + int ret; + struct mbo *mbo; + struct aim_channel *channel = to_channel(inode->i_cdev); + + mutex_lock(&channel->io_mutex); + if (!channel->dev) { + mutex_unlock(&channel->io_mutex); + atomic_dec(&channel->access_ref); + device_destroy(aim_class, channel->devno); + cdev_del(&channel->cdev); + kfifo_free(&channel->fifo); + list_del(&channel->list); + kfree(channel); + ida_simple_remove(&minor_id, MINOR(channel->devno)); + wake_up_interruptible(&channel->wq); + return 0; + } + mutex_unlock(&channel->io_mutex); + + while (0 != kfifo_out((struct kfifo *)&channel->fifo, &mbo, 1)) + most_put_mbo(mbo); + if (channel->keep_mbo == true) + most_put_mbo(channel->stacked_mbo); + ret = most_stop_channel(channel->iface, channel->channel_id); + atomic_dec(&channel->access_ref); + wake_up_interruptible(&channel->wq); + return ret; +} + +/** + * aim_write - implements the syscall to write to the device + * @filp: file pointer + * @buf: pointer to user buffer + * @count: number of bytes to write + * @offset: offset from where to start writing + */ +static ssize_t aim_write(struct file *filp, const char __user *buf, + size_t count, loff_t *offset) +{ + int ret, err; + size_t actual_len = 0; + size_t max_len = 0; + ssize_t retval; + struct mbo *mbo; + struct aim_channel *channel = filp->private_data; + + mutex_lock(&channel->io_mutex); + if (unlikely(!channel->dev)) { + mutex_unlock(&channel->io_mutex); + return -EPIPE; + } + mutex_unlock(&channel->io_mutex); + + mbo = most_get_mbo(channel->iface, channel->channel_id); + + if (!mbo && channel->dev) { + if ((filp->f_flags & O_NONBLOCK)) + return -EAGAIN; + if (wait_event_interruptible( + channel->wq, + (mbo = most_get_mbo(channel->iface, + channel->channel_id)) || + (channel->dev == NULL))) + return -ERESTARTSYS; + } + + mutex_lock(&channel->io_mutex); + if (unlikely(!channel->dev)) { + mutex_unlock(&channel->io_mutex); + err = -EPIPE; + goto error; + } + mutex_unlock(&channel->io_mutex); + + max_len = channel->cfg->buffer_size; + actual_len = min(count, max_len); + mbo->buffer_length = actual_len; + + retval = copy_from_user(mbo->virt_address, buf, mbo->buffer_length); + if (retval) { + err = -EIO; + goto error; + } + + ret = most_submit_mbo(mbo); + if (ret) { + pr_info("submitting MBO to core failed\n"); + err = ret; + goto error; + } + return actual_len - retval; +error: + most_put_mbo(mbo); + return err; +} + +/** + * aim_read - implements the syscall to read from the device + * @filp: file pointer + * @buf: pointer to user buffer + * @count: number of bytes to read + * @offset: offset from where to start reading + */ +static ssize_t +aim_read(struct file *filp, char __user *buf, size_t count, loff_t *offset) +{ + ssize_t retval; + size_t not_copied, proc_len; + struct mbo *mbo; + struct aim_channel *channel = filp->private_data; + + if (channel->keep_mbo == true) { + mbo = channel->stacked_mbo; + channel->keep_mbo = false; + goto start_copy; + } + while ((0 == kfifo_out(&channel->fifo, &mbo, 1)) + && (channel->dev != NULL)) { + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + if (wait_event_interruptible(channel->wq, + (!kfifo_is_empty(&channel->fifo) || + (channel->dev == NULL)))) + return -ERESTARTSYS; + } + +start_copy: + /* make sure we don't submit to gone devices */ + mutex_lock(&channel->io_mutex); + if (unlikely(!channel->dev)) { + mutex_unlock(&channel->io_mutex); + return -EIO; + } + + if (count < mbo->processed_length) + channel->keep_mbo = true; + + proc_len = min((int)count, + (int)(mbo->processed_length - channel->mbo_offs)); + + not_copied = copy_to_user(buf, + mbo->virt_address + channel->mbo_offs, + proc_len); + + retval = not_copied ? proc_len - not_copied : proc_len; + + if (channel->keep_mbo == true) { + channel->mbo_offs = retval; + channel->stacked_mbo = mbo; + } else { + most_put_mbo(mbo); + channel->mbo_offs = 0; + } + mutex_unlock(&channel->io_mutex); + return retval; +} + +/** + * Initialization of struct file_operations + */ +static const struct file_operations channel_fops = { + .owner = THIS_MODULE, + .read = aim_read, + .write = aim_write, + .open = aim_open, + .release = aim_close, +}; + +/** + * aim_disconnect_channel - disconnect a channel + * @iface: pointer to interface instance + * @channel_id: channel index + * + * This frees allocated memory and removes the cdev that represents this + * channel in user space. + */ +int aim_disconnect_channel(struct most_interface *iface, int channel_id) +{ + struct aim_channel *channel; + unsigned long flags; + + if (!iface) { + pr_info("Bad interface pointer\n"); + return -EINVAL; + } + + channel = get_channel(iface, channel_id); + if (channel == NULL) + return -ENXIO; + + mutex_lock(&channel->io_mutex); + channel->dev = NULL; + mutex_unlock(&channel->io_mutex); + + if (atomic_read(&channel->access_ref)) { + device_destroy(aim_class, channel->devno); + cdev_del(&channel->cdev); + kfifo_free(&channel->fifo); + ida_simple_remove(&minor_id, MINOR(channel->devno)); + spin_lock_irqsave(&ch_list_lock, flags); + list_del(&channel->list); + spin_unlock_irqrestore(&ch_list_lock, flags); + kfree(channel); + } else { + wake_up_interruptible(&channel->wq); + } + return 0; +} + +/** + * aim_rx_completion - completion handler for rx channels + * @mbo: pointer to buffer object that has completed + * + * This searches for the channel linked to this MBO and stores it in the local + * fifo buffer. + */ +int aim_rx_completion(struct mbo *mbo) +{ + struct aim_channel *channel; + + if (!mbo) + return -EINVAL; + + channel = get_channel(mbo->ifp, mbo->hdm_channel_id); + if (channel == NULL) + return -ENXIO; + + kfifo_in(&channel->fifo, &mbo, 1); +#ifdef DEBUG_MESG + if (kfifo_is_full(&channel->fifo)) + pr_info("WARN: Fifo is full\n"); +#endif + wake_up_interruptible(&channel->wq); + return 0; +} + +/** + * aim_tx_completion - completion handler for tx channels + * @iface: pointer to interface instance + * @channel_id: channel index/ID + * + * This wakes sleeping processes in the wait-queue. + */ +int aim_tx_completion(struct most_interface *iface, int channel_id) +{ + struct aim_channel *channel; + + if (!iface) { + pr_info("Bad interface pointer\n"); + return -EINVAL; + } + if ((channel_id < 0) || (channel_id >= iface->num_channels)) { + pr_info("Channel ID out of range\n"); + return -EINVAL; + } + + channel = get_channel(iface, channel_id); + if (channel == NULL) + return -ENXIO; + wake_up_interruptible(&channel->wq); + return 0; +} + +struct most_aim cdev_aim; + +/** + * aim_probe - probe function of the driver module + * @iface: pointer to interface instance + * @channel_id: channel index/ID + * @cfg: pointer to actual channel configuration + * @parent: pointer to kobject (needed for sysfs hook-up) + * @name: name of the device to be created + * + * This allocates achannel object and creates the device node in /dev + * + * Returns 0 on success or error code otherwise. + */ +int aim_probe(struct most_interface *iface, int channel_id, + struct most_channel_config *cfg, + struct kobject *parent, char *name) +{ + struct aim_channel *channel; + unsigned long cl_flags; + int retval; + int current_minor; + + if ((!iface) || (!cfg) || (!parent) || (!name)) { + pr_info("Probing AIM with bad arguments"); + return -EINVAL; + } + channel = get_channel(iface, channel_id); + if (channel) + return -EEXIST; + + current_minor = ida_simple_get(&minor_id, 0, 0, GFP_KERNEL); + if (current_minor < 0) + return current_minor; + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (!channel) { + pr_info("failed to alloc channel object\n"); + retval = -ENOMEM; + goto error_alloc_channel; + } + + channel->devno = MKDEV(major, current_minor); + cdev_init(&channel->cdev, &channel_fops); + channel->cdev.owner = THIS_MODULE; + cdev_add(&channel->cdev, channel->devno, 1); + channel->iface = iface; + channel->cfg = cfg; + channel->channel_id = channel_id; + channel->mbo_offs = 0; + atomic_set(&channel->access_ref, -1); + INIT_KFIFO(channel->fifo); + retval = kfifo_alloc(&channel->fifo, cfg->num_buffers, GFP_KERNEL); + if (retval) { + pr_info("failed to alloc channel kfifo"); + goto error_alloc_kfifo; + } + init_waitqueue_head(&channel->wq); + mutex_init(&channel->io_mutex); + spin_lock_irqsave(&ch_list_lock, cl_flags); + list_add_tail(&channel->list, &channel_list); + spin_unlock_irqrestore(&ch_list_lock, cl_flags); + channel->dev = device_create(aim_class, + NULL, + channel->devno, + NULL, + "%s", name); + + retval = IS_ERR(channel->dev); + if (retval) { + pr_info("failed to create new device node %s\n", name); + goto error_create_device; + } + kobject_uevent(&channel->dev->kobj, KOBJ_ADD); + return 0; + +error_create_device: + kfifo_free(&channel->fifo); + list_del(&channel->list); +error_alloc_kfifo: + cdev_del(&channel->cdev); + kfree(channel); +error_alloc_channel: + ida_simple_remove(&minor_id, current_minor); + return retval; +} + +struct most_aim cdev_aim = { + .name = "cdev", + .probe_channel = aim_probe, + .disconnect_channel = aim_disconnect_channel, + .rx_completion = aim_rx_completion, + .tx_completion = aim_tx_completion, +}; + +static int __init mod_init(void) +{ + pr_info("init()\n"); + + INIT_LIST_HEAD(&channel_list); + spin_lock_init(&ch_list_lock); + ida_init(&minor_id); + + if (alloc_chrdev_region(&aim_devno, 0, 50, "cdev") < 0) + return -EIO; + major = MAJOR(aim_devno); + + aim_class = class_create(THIS_MODULE, "most_cdev_aim"); + if (IS_ERR(aim_class)) { + pr_err("no udev support\n"); + goto free_cdev; + } + + if (most_register_aim(&cdev_aim)) + goto dest_class; + return 0; + +dest_class: + class_destroy(aim_class); +free_cdev: + unregister_chrdev_region(aim_devno, 1); + return -EIO; +} + +static void __exit mod_exit(void) +{ + struct aim_channel *channel, *tmp; + + pr_info("exit module\n"); + + most_deregister_aim(&cdev_aim); + + list_for_each_entry_safe(channel, tmp, &channel_list, list) { + device_destroy(aim_class, channel->devno); + cdev_del(&channel->cdev); + kfifo_free(&channel->fifo); + list_del(&channel->list); + ida_simple_remove(&minor_id, MINOR(channel->devno)); + kfree(channel); + } + class_destroy(aim_class); + unregister_chrdev_region(aim_devno, 1); + ida_destroy(&minor_id); +} + +module_init(mod_init); +module_exit(mod_exit); +MODULE_AUTHOR("Christian Gromm "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("character device AIM for mostcore");