From ceea93444808c7d1fd07a01927937d20237d849e Mon Sep 17 00:00:00 2001 From: Christian Gromm Date: Thu, 20 Aug 2020 13:23:15 +0200 Subject: drivers: most: add character device interface driver This patch adds the character device (cdev) driver source file most_cdev.c and modifies the Makefiles and Kconfigs accordingly. Signed-off-by: Christian Gromm Link: https://lore.kernel.org/r/1597922595-27493-1-git-send-email-christian.gromm@microchip.com Signed-off-by: Greg Kroah-Hartman --- drivers/most/Kconfig | 9 + drivers/most/Makefile | 1 + drivers/most/most_cdev.c | 543 +++++++++++++++++++++++++++++++++++++ drivers/staging/most/Kconfig | 2 - drivers/staging/most/Makefile | 1 - drivers/staging/most/cdev/Kconfig | 13 - drivers/staging/most/cdev/Makefile | 4 - drivers/staging/most/cdev/cdev.c | 543 ------------------------------------- 8 files changed, 553 insertions(+), 563 deletions(-) create mode 100644 drivers/most/most_cdev.c delete mode 100644 drivers/staging/most/cdev/Kconfig delete mode 100644 drivers/staging/most/cdev/Makefile delete mode 100644 drivers/staging/most/cdev/cdev.c diff --git a/drivers/most/Kconfig b/drivers/most/Kconfig index 60fc0820dad3..ebfe84e69715 100644 --- a/drivers/most/Kconfig +++ b/drivers/most/Kconfig @@ -23,4 +23,13 @@ config MOST_USB_HDM To compile this driver as a module, choose M here: the module will be called most_usb. + +config MOST_CDEV + tristate "Cdev" + + 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 most_cdev. endif diff --git a/drivers/most/Makefile b/drivers/most/Makefile index 6a3cb9056288..8b53ca46633f 100644 --- a/drivers/most/Makefile +++ b/drivers/most/Makefile @@ -4,3 +4,4 @@ most_core-y := core.o \ configfs.o obj-$(CONFIG_MOST_USB_HDM) += most_usb.o +obj-$(CONFIG_MOST_CDEV) += most_cdev.o diff --git a/drivers/most/most_cdev.c b/drivers/most/most_cdev.c new file mode 100644 index 000000000000..044880760b58 --- /dev/null +++ b/drivers/most/most_cdev.c @@ -0,0 +1,543 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * cdev.c - Character device component for Mostcore + * + * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CHRDEV_REGION_SIZE 50 + +static struct cdev_component { + dev_t devno; + struct ida minor_id; + unsigned int major; + struct class *class; + struct most_component cc; +} comp; + +struct comp_channel { + wait_queue_head_t wq; + spinlock_t unlink; /* synchronization lock to unlink channels */ + 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; + size_t mbo_offs; + DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *)); + int access_ref; + struct list_head list; +}; + +#define to_channel(d) container_of(d, struct comp_channel, cdev) +static struct list_head channel_list; +static spinlock_t ch_list_lock; + +static inline bool ch_has_mbo(struct comp_channel *c) +{ + return channel_has_mbo(c->iface, c->channel_id, &comp.cc) > 0; +} + +static inline struct mbo *ch_get_mbo(struct comp_channel *c, struct mbo **mbo) +{ + if (!kfifo_peek(&c->fifo, mbo)) { + *mbo = most_get_mbo(c->iface, c->channel_id, &comp.cc); + if (*mbo) + kfifo_in(&c->fifo, mbo, 1); + } + return *mbo; +} + +static struct comp_channel *get_channel(struct most_interface *iface, int id) +{ + struct comp_channel *c, *tmp; + unsigned long flags; + + spin_lock_irqsave(&ch_list_lock, flags); + list_for_each_entry_safe(c, tmp, &channel_list, list) { + if ((c->iface == iface) && (c->channel_id == id)) { + spin_unlock_irqrestore(&ch_list_lock, flags); + return c; + } + } + spin_unlock_irqrestore(&ch_list_lock, flags); + return NULL; +} + +static void stop_channel(struct comp_channel *c) +{ + struct mbo *mbo; + + while (kfifo_out((struct kfifo *)&c->fifo, &mbo, 1)) + most_put_mbo(mbo); + most_stop_channel(c->iface, c->channel_id, &comp.cc); +} + +static void destroy_cdev(struct comp_channel *c) +{ + unsigned long flags; + + device_destroy(comp.class, c->devno); + cdev_del(&c->cdev); + spin_lock_irqsave(&ch_list_lock, flags); + list_del(&c->list); + spin_unlock_irqrestore(&ch_list_lock, flags); +} + +static void destroy_channel(struct comp_channel *c) +{ + ida_simple_remove(&comp.minor_id, MINOR(c->devno)); + kfifo_free(&c->fifo); + kfree(c); +} + +/** + * comp_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 comp_open(struct inode *inode, struct file *filp) +{ + struct comp_channel *c; + int ret; + + c = to_channel(inode->i_cdev); + filp->private_data = c; + + if (((c->cfg->direction == MOST_CH_RX) && + ((filp->f_flags & O_ACCMODE) != O_RDONLY)) || + ((c->cfg->direction == MOST_CH_TX) && + ((filp->f_flags & O_ACCMODE) != O_WRONLY))) { + return -EACCES; + } + + mutex_lock(&c->io_mutex); + if (!c->dev) { + mutex_unlock(&c->io_mutex); + return -ENODEV; + } + + if (c->access_ref) { + mutex_unlock(&c->io_mutex); + return -EBUSY; + } + + c->mbo_offs = 0; + ret = most_start_channel(c->iface, c->channel_id, &comp.cc); + if (!ret) + c->access_ref = 1; + mutex_unlock(&c->io_mutex); + return ret; +} + +/** + * comp_close - implements the syscall to close the device + * @inode: inode pointer + * @filp: file pointer + * + * This stops the channel within the core. + */ +static int comp_close(struct inode *inode, struct file *filp) +{ + struct comp_channel *c = to_channel(inode->i_cdev); + + mutex_lock(&c->io_mutex); + spin_lock(&c->unlink); + c->access_ref = 0; + spin_unlock(&c->unlink); + if (c->dev) { + stop_channel(c); + mutex_unlock(&c->io_mutex); + } else { + mutex_unlock(&c->io_mutex); + destroy_channel(c); + } + return 0; +} + +/** + * comp_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 comp_write(struct file *filp, const char __user *buf, + size_t count, loff_t *offset) +{ + int ret; + size_t to_copy, left; + struct mbo *mbo = NULL; + struct comp_channel *c = filp->private_data; + + mutex_lock(&c->io_mutex); + while (c->dev && !ch_get_mbo(c, &mbo)) { + mutex_unlock(&c->io_mutex); + + if ((filp->f_flags & O_NONBLOCK)) + return -EAGAIN; + if (wait_event_interruptible(c->wq, ch_has_mbo(c) || !c->dev)) + return -ERESTARTSYS; + mutex_lock(&c->io_mutex); + } + + if (unlikely(!c->dev)) { + ret = -ENODEV; + goto unlock; + } + + to_copy = min(count, c->cfg->buffer_size - c->mbo_offs); + left = copy_from_user(mbo->virt_address + c->mbo_offs, buf, to_copy); + if (left == to_copy) { + ret = -EFAULT; + goto unlock; + } + + c->mbo_offs += to_copy - left; + if (c->mbo_offs >= c->cfg->buffer_size || + c->cfg->data_type == MOST_CH_CONTROL || + c->cfg->data_type == MOST_CH_ASYNC) { + kfifo_skip(&c->fifo); + mbo->buffer_length = c->mbo_offs; + c->mbo_offs = 0; + most_submit_mbo(mbo); + } + + ret = to_copy - left; +unlock: + mutex_unlock(&c->io_mutex); + return ret; +} + +/** + * comp_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 +comp_read(struct file *filp, char __user *buf, size_t count, loff_t *offset) +{ + size_t to_copy, not_copied, copied; + struct mbo *mbo = NULL; + struct comp_channel *c = filp->private_data; + + mutex_lock(&c->io_mutex); + while (c->dev && !kfifo_peek(&c->fifo, &mbo)) { + mutex_unlock(&c->io_mutex); + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + if (wait_event_interruptible(c->wq, + (!kfifo_is_empty(&c->fifo) || + (!c->dev)))) + return -ERESTARTSYS; + mutex_lock(&c->io_mutex); + } + + /* make sure we don't submit to gone devices */ + if (unlikely(!c->dev)) { + mutex_unlock(&c->io_mutex); + return -ENODEV; + } + + to_copy = min_t(size_t, + count, + mbo->processed_length - c->mbo_offs); + + not_copied = copy_to_user(buf, + mbo->virt_address + c->mbo_offs, + to_copy); + + copied = to_copy - not_copied; + + c->mbo_offs += copied; + if (c->mbo_offs >= mbo->processed_length) { + kfifo_skip(&c->fifo); + most_put_mbo(mbo); + c->mbo_offs = 0; + } + mutex_unlock(&c->io_mutex); + return copied; +} + +static __poll_t comp_poll(struct file *filp, poll_table *wait) +{ + struct comp_channel *c = filp->private_data; + __poll_t mask = 0; + + poll_wait(filp, &c->wq, wait); + + mutex_lock(&c->io_mutex); + if (c->cfg->direction == MOST_CH_RX) { + if (!c->dev || !kfifo_is_empty(&c->fifo)) + mask |= EPOLLIN | EPOLLRDNORM; + } else { + if (!c->dev || !kfifo_is_empty(&c->fifo) || ch_has_mbo(c)) + mask |= EPOLLOUT | EPOLLWRNORM; + } + mutex_unlock(&c->io_mutex); + return mask; +} + +/** + * Initialization of struct file_operations + */ +static const struct file_operations channel_fops = { + .owner = THIS_MODULE, + .read = comp_read, + .write = comp_write, + .open = comp_open, + .release = comp_close, + .poll = comp_poll, +}; + +/** + * comp_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. + */ +static int comp_disconnect_channel(struct most_interface *iface, int channel_id) +{ + struct comp_channel *c; + + c = get_channel(iface, channel_id); + if (!c) + return -EINVAL; + + mutex_lock(&c->io_mutex); + spin_lock(&c->unlink); + c->dev = NULL; + spin_unlock(&c->unlink); + destroy_cdev(c); + if (c->access_ref) { + stop_channel(c); + wake_up_interruptible(&c->wq); + mutex_unlock(&c->io_mutex); + } else { + mutex_unlock(&c->io_mutex); + destroy_channel(c); + } + return 0; +} + +/** + * comp_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. + */ +static int comp_rx_completion(struct mbo *mbo) +{ + struct comp_channel *c; + + if (!mbo) + return -EINVAL; + + c = get_channel(mbo->ifp, mbo->hdm_channel_id); + if (!c) + return -EINVAL; + + spin_lock(&c->unlink); + if (!c->access_ref || !c->dev) { + spin_unlock(&c->unlink); + return -ENODEV; + } + kfifo_in(&c->fifo, &mbo, 1); + spin_unlock(&c->unlink); +#ifdef DEBUG_MESG + if (kfifo_is_full(&c->fifo)) + dev_warn(c->dev, "Fifo is full\n"); +#endif + wake_up_interruptible(&c->wq); + return 0; +} + +/** + * comp_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. + */ +static int comp_tx_completion(struct most_interface *iface, int channel_id) +{ + struct comp_channel *c; + + c = get_channel(iface, channel_id); + if (!c) + return -EINVAL; + + if ((channel_id < 0) || (channel_id >= iface->num_channels)) { + dev_warn(c->dev, "Channel ID out of range\n"); + return -EINVAL; + } + + wake_up_interruptible(&c->wq); + return 0; +} + +/** + * comp_probe - probe function of the driver module + * @iface: pointer to interface instance + * @channel_id: channel index/ID + * @cfg: pointer to actual channel configuration + * @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. + */ +static int comp_probe(struct most_interface *iface, int channel_id, + struct most_channel_config *cfg, char *name, char *args) +{ + struct comp_channel *c; + unsigned long cl_flags; + int retval; + int current_minor; + + if (!cfg || !name) + return -EINVAL; + + c = get_channel(iface, channel_id); + if (c) + return -EEXIST; + + current_minor = ida_simple_get(&comp.minor_id, 0, 0, GFP_KERNEL); + if (current_minor < 0) + return current_minor; + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) { + retval = -ENOMEM; + goto err_remove_ida; + } + + c->devno = MKDEV(comp.major, current_minor); + cdev_init(&c->cdev, &channel_fops); + c->cdev.owner = THIS_MODULE; + retval = cdev_add(&c->cdev, c->devno, 1); + if (retval < 0) + goto err_free_c; + c->iface = iface; + c->cfg = cfg; + c->channel_id = channel_id; + c->access_ref = 0; + spin_lock_init(&c->unlink); + INIT_KFIFO(c->fifo); + retval = kfifo_alloc(&c->fifo, cfg->num_buffers, GFP_KERNEL); + if (retval) + goto err_del_cdev_and_free_channel; + init_waitqueue_head(&c->wq); + mutex_init(&c->io_mutex); + spin_lock_irqsave(&ch_list_lock, cl_flags); + list_add_tail(&c->list, &channel_list); + spin_unlock_irqrestore(&ch_list_lock, cl_flags); + c->dev = device_create(comp.class, NULL, c->devno, NULL, "%s", name); + + if (IS_ERR(c->dev)) { + retval = PTR_ERR(c->dev); + goto err_free_kfifo_and_del_list; + } + kobject_uevent(&c->dev->kobj, KOBJ_ADD); + return 0; + +err_free_kfifo_and_del_list: + kfifo_free(&c->fifo); + list_del(&c->list); +err_del_cdev_and_free_channel: + cdev_del(&c->cdev); +err_free_c: + kfree(c); +err_remove_ida: + ida_simple_remove(&comp.minor_id, current_minor); + return retval; +} + +static struct cdev_component comp = { + .cc = { + .mod = THIS_MODULE, + .name = "cdev", + .probe_channel = comp_probe, + .disconnect_channel = comp_disconnect_channel, + .rx_completion = comp_rx_completion, + .tx_completion = comp_tx_completion, + }, +}; + +static int __init mod_init(void) +{ + int err; + + comp.class = class_create(THIS_MODULE, "most_cdev"); + if (IS_ERR(comp.class)) + return PTR_ERR(comp.class); + + INIT_LIST_HEAD(&channel_list); + spin_lock_init(&ch_list_lock); + ida_init(&comp.minor_id); + + err = alloc_chrdev_region(&comp.devno, 0, CHRDEV_REGION_SIZE, "cdev"); + if (err < 0) + goto dest_ida; + comp.major = MAJOR(comp.devno); + err = most_register_component(&comp.cc); + if (err) + goto free_cdev; + err = most_register_configfs_subsys(&comp.cc); + if (err) + goto deregister_comp; + return 0; + +deregister_comp: + most_deregister_component(&comp.cc); +free_cdev: + unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE); +dest_ida: + ida_destroy(&comp.minor_id); + class_destroy(comp.class); + return err; +} + +static void __exit mod_exit(void) +{ + struct comp_channel *c, *tmp; + + most_deregister_configfs_subsys(&comp.cc); + most_deregister_component(&comp.cc); + + list_for_each_entry_safe(c, tmp, &channel_list, list) { + destroy_cdev(c); + destroy_channel(c); + } + unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE); + ida_destroy(&comp.minor_id); + class_destroy(comp.class); +} + +module_init(mod_init); +module_exit(mod_exit); +MODULE_AUTHOR("Christian Gromm "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("character device component for mostcore"); diff --git a/drivers/staging/most/Kconfig b/drivers/staging/most/Kconfig index c35fb34fae79..535e6dec3504 100644 --- a/drivers/staging/most/Kconfig +++ b/drivers/staging/most/Kconfig @@ -18,8 +18,6 @@ menuconfig MOST_COMPONENTS if MOST_COMPONENTS -source "drivers/staging/most/cdev/Kconfig" - source "drivers/staging/most/net/Kconfig" source "drivers/staging/most/sound/Kconfig" diff --git a/drivers/staging/most/Makefile b/drivers/staging/most/Makefile index 7c10b84ebac0..be94673209f5 100644 --- a/drivers/staging/most/Makefile +++ b/drivers/staging/most/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_MOST_CDEV) += cdev/ obj-$(CONFIG_MOST_NET) += net/ obj-$(CONFIG_MOST_SOUND) += sound/ obj-$(CONFIG_MOST_VIDEO) += video/ diff --git a/drivers/staging/most/cdev/Kconfig b/drivers/staging/most/cdev/Kconfig deleted file mode 100644 index dab99477858e..000000000000 --- a/drivers/staging/most/cdev/Kconfig +++ /dev/null @@ -1,13 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -# -# MOST Cdev configuration -# - -config MOST_CDEV - tristate "Cdev" - - 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 most_cdev. diff --git a/drivers/staging/most/cdev/Makefile b/drivers/staging/most/cdev/Makefile deleted file mode 100644 index ef90cd71994a..000000000000 --- a/drivers/staging/most/cdev/Makefile +++ /dev/null @@ -1,4 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_MOST_CDEV) += most_cdev.o - -most_cdev-objs := cdev.o diff --git a/drivers/staging/most/cdev/cdev.c b/drivers/staging/most/cdev/cdev.c deleted file mode 100644 index 044880760b58..000000000000 --- a/drivers/staging/most/cdev/cdev.c +++ /dev/null @@ -1,543 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * cdev.c - Character device component for Mostcore - * - * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define CHRDEV_REGION_SIZE 50 - -static struct cdev_component { - dev_t devno; - struct ida minor_id; - unsigned int major; - struct class *class; - struct most_component cc; -} comp; - -struct comp_channel { - wait_queue_head_t wq; - spinlock_t unlink; /* synchronization lock to unlink channels */ - 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; - size_t mbo_offs; - DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *)); - int access_ref; - struct list_head list; -}; - -#define to_channel(d) container_of(d, struct comp_channel, cdev) -static struct list_head channel_list; -static spinlock_t ch_list_lock; - -static inline bool ch_has_mbo(struct comp_channel *c) -{ - return channel_has_mbo(c->iface, c->channel_id, &comp.cc) > 0; -} - -static inline struct mbo *ch_get_mbo(struct comp_channel *c, struct mbo **mbo) -{ - if (!kfifo_peek(&c->fifo, mbo)) { - *mbo = most_get_mbo(c->iface, c->channel_id, &comp.cc); - if (*mbo) - kfifo_in(&c->fifo, mbo, 1); - } - return *mbo; -} - -static struct comp_channel *get_channel(struct most_interface *iface, int id) -{ - struct comp_channel *c, *tmp; - unsigned long flags; - - spin_lock_irqsave(&ch_list_lock, flags); - list_for_each_entry_safe(c, tmp, &channel_list, list) { - if ((c->iface == iface) && (c->channel_id == id)) { - spin_unlock_irqrestore(&ch_list_lock, flags); - return c; - } - } - spin_unlock_irqrestore(&ch_list_lock, flags); - return NULL; -} - -static void stop_channel(struct comp_channel *c) -{ - struct mbo *mbo; - - while (kfifo_out((struct kfifo *)&c->fifo, &mbo, 1)) - most_put_mbo(mbo); - most_stop_channel(c->iface, c->channel_id, &comp.cc); -} - -static void destroy_cdev(struct comp_channel *c) -{ - unsigned long flags; - - device_destroy(comp.class, c->devno); - cdev_del(&c->cdev); - spin_lock_irqsave(&ch_list_lock, flags); - list_del(&c->list); - spin_unlock_irqrestore(&ch_list_lock, flags); -} - -static void destroy_channel(struct comp_channel *c) -{ - ida_simple_remove(&comp.minor_id, MINOR(c->devno)); - kfifo_free(&c->fifo); - kfree(c); -} - -/** - * comp_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 comp_open(struct inode *inode, struct file *filp) -{ - struct comp_channel *c; - int ret; - - c = to_channel(inode->i_cdev); - filp->private_data = c; - - if (((c->cfg->direction == MOST_CH_RX) && - ((filp->f_flags & O_ACCMODE) != O_RDONLY)) || - ((c->cfg->direction == MOST_CH_TX) && - ((filp->f_flags & O_ACCMODE) != O_WRONLY))) { - return -EACCES; - } - - mutex_lock(&c->io_mutex); - if (!c->dev) { - mutex_unlock(&c->io_mutex); - return -ENODEV; - } - - if (c->access_ref) { - mutex_unlock(&c->io_mutex); - return -EBUSY; - } - - c->mbo_offs = 0; - ret = most_start_channel(c->iface, c->channel_id, &comp.cc); - if (!ret) - c->access_ref = 1; - mutex_unlock(&c->io_mutex); - return ret; -} - -/** - * comp_close - implements the syscall to close the device - * @inode: inode pointer - * @filp: file pointer - * - * This stops the channel within the core. - */ -static int comp_close(struct inode *inode, struct file *filp) -{ - struct comp_channel *c = to_channel(inode->i_cdev); - - mutex_lock(&c->io_mutex); - spin_lock(&c->unlink); - c->access_ref = 0; - spin_unlock(&c->unlink); - if (c->dev) { - stop_channel(c); - mutex_unlock(&c->io_mutex); - } else { - mutex_unlock(&c->io_mutex); - destroy_channel(c); - } - return 0; -} - -/** - * comp_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 comp_write(struct file *filp, const char __user *buf, - size_t count, loff_t *offset) -{ - int ret; - size_t to_copy, left; - struct mbo *mbo = NULL; - struct comp_channel *c = filp->private_data; - - mutex_lock(&c->io_mutex); - while (c->dev && !ch_get_mbo(c, &mbo)) { - mutex_unlock(&c->io_mutex); - - if ((filp->f_flags & O_NONBLOCK)) - return -EAGAIN; - if (wait_event_interruptible(c->wq, ch_has_mbo(c) || !c->dev)) - return -ERESTARTSYS; - mutex_lock(&c->io_mutex); - } - - if (unlikely(!c->dev)) { - ret = -ENODEV; - goto unlock; - } - - to_copy = min(count, c->cfg->buffer_size - c->mbo_offs); - left = copy_from_user(mbo->virt_address + c->mbo_offs, buf, to_copy); - if (left == to_copy) { - ret = -EFAULT; - goto unlock; - } - - c->mbo_offs += to_copy - left; - if (c->mbo_offs >= c->cfg->buffer_size || - c->cfg->data_type == MOST_CH_CONTROL || - c->cfg->data_type == MOST_CH_ASYNC) { - kfifo_skip(&c->fifo); - mbo->buffer_length = c->mbo_offs; - c->mbo_offs = 0; - most_submit_mbo(mbo); - } - - ret = to_copy - left; -unlock: - mutex_unlock(&c->io_mutex); - return ret; -} - -/** - * comp_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 -comp_read(struct file *filp, char __user *buf, size_t count, loff_t *offset) -{ - size_t to_copy, not_copied, copied; - struct mbo *mbo = NULL; - struct comp_channel *c = filp->private_data; - - mutex_lock(&c->io_mutex); - while (c->dev && !kfifo_peek(&c->fifo, &mbo)) { - mutex_unlock(&c->io_mutex); - if (filp->f_flags & O_NONBLOCK) - return -EAGAIN; - if (wait_event_interruptible(c->wq, - (!kfifo_is_empty(&c->fifo) || - (!c->dev)))) - return -ERESTARTSYS; - mutex_lock(&c->io_mutex); - } - - /* make sure we don't submit to gone devices */ - if (unlikely(!c->dev)) { - mutex_unlock(&c->io_mutex); - return -ENODEV; - } - - to_copy = min_t(size_t, - count, - mbo->processed_length - c->mbo_offs); - - not_copied = copy_to_user(buf, - mbo->virt_address + c->mbo_offs, - to_copy); - - copied = to_copy - not_copied; - - c->mbo_offs += copied; - if (c->mbo_offs >= mbo->processed_length) { - kfifo_skip(&c->fifo); - most_put_mbo(mbo); - c->mbo_offs = 0; - } - mutex_unlock(&c->io_mutex); - return copied; -} - -static __poll_t comp_poll(struct file *filp, poll_table *wait) -{ - struct comp_channel *c = filp->private_data; - __poll_t mask = 0; - - poll_wait(filp, &c->wq, wait); - - mutex_lock(&c->io_mutex); - if (c->cfg->direction == MOST_CH_RX) { - if (!c->dev || !kfifo_is_empty(&c->fifo)) - mask |= EPOLLIN | EPOLLRDNORM; - } else { - if (!c->dev || !kfifo_is_empty(&c->fifo) || ch_has_mbo(c)) - mask |= EPOLLOUT | EPOLLWRNORM; - } - mutex_unlock(&c->io_mutex); - return mask; -} - -/** - * Initialization of struct file_operations - */ -static const struct file_operations channel_fops = { - .owner = THIS_MODULE, - .read = comp_read, - .write = comp_write, - .open = comp_open, - .release = comp_close, - .poll = comp_poll, -}; - -/** - * comp_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. - */ -static int comp_disconnect_channel(struct most_interface *iface, int channel_id) -{ - struct comp_channel *c; - - c = get_channel(iface, channel_id); - if (!c) - return -EINVAL; - - mutex_lock(&c->io_mutex); - spin_lock(&c->unlink); - c->dev = NULL; - spin_unlock(&c->unlink); - destroy_cdev(c); - if (c->access_ref) { - stop_channel(c); - wake_up_interruptible(&c->wq); - mutex_unlock(&c->io_mutex); - } else { - mutex_unlock(&c->io_mutex); - destroy_channel(c); - } - return 0; -} - -/** - * comp_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. - */ -static int comp_rx_completion(struct mbo *mbo) -{ - struct comp_channel *c; - - if (!mbo) - return -EINVAL; - - c = get_channel(mbo->ifp, mbo->hdm_channel_id); - if (!c) - return -EINVAL; - - spin_lock(&c->unlink); - if (!c->access_ref || !c->dev) { - spin_unlock(&c->unlink); - return -ENODEV; - } - kfifo_in(&c->fifo, &mbo, 1); - spin_unlock(&c->unlink); -#ifdef DEBUG_MESG - if (kfifo_is_full(&c->fifo)) - dev_warn(c->dev, "Fifo is full\n"); -#endif - wake_up_interruptible(&c->wq); - return 0; -} - -/** - * comp_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. - */ -static int comp_tx_completion(struct most_interface *iface, int channel_id) -{ - struct comp_channel *c; - - c = get_channel(iface, channel_id); - if (!c) - return -EINVAL; - - if ((channel_id < 0) || (channel_id >= iface->num_channels)) { - dev_warn(c->dev, "Channel ID out of range\n"); - return -EINVAL; - } - - wake_up_interruptible(&c->wq); - return 0; -} - -/** - * comp_probe - probe function of the driver module - * @iface: pointer to interface instance - * @channel_id: channel index/ID - * @cfg: pointer to actual channel configuration - * @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. - */ -static int comp_probe(struct most_interface *iface, int channel_id, - struct most_channel_config *cfg, char *name, char *args) -{ - struct comp_channel *c; - unsigned long cl_flags; - int retval; - int current_minor; - - if (!cfg || !name) - return -EINVAL; - - c = get_channel(iface, channel_id); - if (c) - return -EEXIST; - - current_minor = ida_simple_get(&comp.minor_id, 0, 0, GFP_KERNEL); - if (current_minor < 0) - return current_minor; - - c = kzalloc(sizeof(*c), GFP_KERNEL); - if (!c) { - retval = -ENOMEM; - goto err_remove_ida; - } - - c->devno = MKDEV(comp.major, current_minor); - cdev_init(&c->cdev, &channel_fops); - c->cdev.owner = THIS_MODULE; - retval = cdev_add(&c->cdev, c->devno, 1); - if (retval < 0) - goto err_free_c; - c->iface = iface; - c->cfg = cfg; - c->channel_id = channel_id; - c->access_ref = 0; - spin_lock_init(&c->unlink); - INIT_KFIFO(c->fifo); - retval = kfifo_alloc(&c->fifo, cfg->num_buffers, GFP_KERNEL); - if (retval) - goto err_del_cdev_and_free_channel; - init_waitqueue_head(&c->wq); - mutex_init(&c->io_mutex); - spin_lock_irqsave(&ch_list_lock, cl_flags); - list_add_tail(&c->list, &channel_list); - spin_unlock_irqrestore(&ch_list_lock, cl_flags); - c->dev = device_create(comp.class, NULL, c->devno, NULL, "%s", name); - - if (IS_ERR(c->dev)) { - retval = PTR_ERR(c->dev); - goto err_free_kfifo_and_del_list; - } - kobject_uevent(&c->dev->kobj, KOBJ_ADD); - return 0; - -err_free_kfifo_and_del_list: - kfifo_free(&c->fifo); - list_del(&c->list); -err_del_cdev_and_free_channel: - cdev_del(&c->cdev); -err_free_c: - kfree(c); -err_remove_ida: - ida_simple_remove(&comp.minor_id, current_minor); - return retval; -} - -static struct cdev_component comp = { - .cc = { - .mod = THIS_MODULE, - .name = "cdev", - .probe_channel = comp_probe, - .disconnect_channel = comp_disconnect_channel, - .rx_completion = comp_rx_completion, - .tx_completion = comp_tx_completion, - }, -}; - -static int __init mod_init(void) -{ - int err; - - comp.class = class_create(THIS_MODULE, "most_cdev"); - if (IS_ERR(comp.class)) - return PTR_ERR(comp.class); - - INIT_LIST_HEAD(&channel_list); - spin_lock_init(&ch_list_lock); - ida_init(&comp.minor_id); - - err = alloc_chrdev_region(&comp.devno, 0, CHRDEV_REGION_SIZE, "cdev"); - if (err < 0) - goto dest_ida; - comp.major = MAJOR(comp.devno); - err = most_register_component(&comp.cc); - if (err) - goto free_cdev; - err = most_register_configfs_subsys(&comp.cc); - if (err) - goto deregister_comp; - return 0; - -deregister_comp: - most_deregister_component(&comp.cc); -free_cdev: - unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE); -dest_ida: - ida_destroy(&comp.minor_id); - class_destroy(comp.class); - return err; -} - -static void __exit mod_exit(void) -{ - struct comp_channel *c, *tmp; - - most_deregister_configfs_subsys(&comp.cc); - most_deregister_component(&comp.cc); - - list_for_each_entry_safe(c, tmp, &channel_list, list) { - destroy_cdev(c); - destroy_channel(c); - } - unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE); - ida_destroy(&comp.minor_id); - class_destroy(comp.class); -} - -module_init(mod_init); -module_exit(mod_exit); -MODULE_AUTHOR("Christian Gromm "); -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("character device component for mostcore"); -- cgit v1.2.3