diff options
Diffstat (limited to 'kernel/drivers/hid/hid-roccat.c')
| -rw-r--r-- | kernel/drivers/hid/hid-roccat.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/kernel/drivers/hid/hid-roccat.c b/kernel/drivers/hid/hid-roccat.c new file mode 100644 index 000000000..65c4ccfcb --- /dev/null +++ b/kernel/drivers/hid/hid-roccat.c @@ -0,0 +1,461 @@ +/* + * Roccat driver for Linux + * + * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net> + */ + +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ + +/* + * Module roccat is a char device used to report special events of roccat + * hardware to userland. These events include requests for on-screen-display of + * profile or dpi settings or requests for execution of macro sequences that are + * not stored in device. The information in these events depends on hid device + * implementation and contains data that is not available in a single hid event + * or else hidraw could have been used. + * It is inspired by hidraw, but uses only one circular buffer for all readers. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cdev.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/hid-roccat.h> +#include <linux/module.h> + +#define ROCCAT_FIRST_MINOR 0 +#define ROCCAT_MAX_DEVICES 8 + +/* should be a power of 2 for performance reason */ +#define ROCCAT_CBUF_SIZE 16 + +struct roccat_report { + uint8_t *value; +}; + +struct roccat_device { + unsigned int minor; + int report_size; + int open; + int exist; + wait_queue_head_t wait; + struct device *dev; + struct hid_device *hid; + struct list_head readers; + /* protects modifications of readers list */ + struct mutex readers_lock; + + /* + * circular_buffer has one writer and multiple readers with their own + * read pointers + */ + struct roccat_report cbuf[ROCCAT_CBUF_SIZE]; + int cbuf_end; + struct mutex cbuf_lock; +}; + +struct roccat_reader { + struct list_head node; + struct roccat_device *device; + int cbuf_start; +}; + +static int roccat_major; +static struct cdev roccat_cdev; + +static struct roccat_device *devices[ROCCAT_MAX_DEVICES]; +/* protects modifications of devices array */ +static DEFINE_MUTEX(devices_lock); + +static ssize_t roccat_read(struct file *file, char __user *buffer, + size_t count, loff_t *ppos) +{ + struct roccat_reader *reader = file->private_data; + struct roccat_device *device = reader->device; + struct roccat_report *report; + ssize_t retval = 0, len; + DECLARE_WAITQUEUE(wait, current); + + mutex_lock(&device->cbuf_lock); + + /* no data? */ + if (reader->cbuf_start == device->cbuf_end) { + add_wait_queue(&device->wait, &wait); + set_current_state(TASK_INTERRUPTIBLE); + + /* wait for data */ + while (reader->cbuf_start == device->cbuf_end) { + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; + break; + } + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + if (!device->exist) { + retval = -EIO; + break; + } + + mutex_unlock(&device->cbuf_lock); + schedule(); + mutex_lock(&device->cbuf_lock); + set_current_state(TASK_INTERRUPTIBLE); + } + + set_current_state(TASK_RUNNING); + remove_wait_queue(&device->wait, &wait); + } + + /* here we either have data or a reason to return if retval is set */ + if (retval) + goto exit_unlock; + + report = &device->cbuf[reader->cbuf_start]; + /* + * If report is larger than requested amount of data, rest of report + * is lost! + */ + len = device->report_size > count ? count : device->report_size; + + if (copy_to_user(buffer, report->value, len)) { + retval = -EFAULT; + goto exit_unlock; + } + retval += len; + reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; + +exit_unlock: + mutex_unlock(&device->cbuf_lock); + return retval; +} + +static unsigned int roccat_poll(struct file *file, poll_table *wait) +{ + struct roccat_reader *reader = file->private_data; + poll_wait(file, &reader->device->wait, wait); + if (reader->cbuf_start != reader->device->cbuf_end) + return POLLIN | POLLRDNORM; + if (!reader->device->exist) + return POLLERR | POLLHUP; + return 0; +} + +static int roccat_open(struct inode *inode, struct file *file) +{ + unsigned int minor = iminor(inode); + struct roccat_reader *reader; + struct roccat_device *device; + int error = 0; + + reader = kzalloc(sizeof(struct roccat_reader), GFP_KERNEL); + if (!reader) + return -ENOMEM; + + mutex_lock(&devices_lock); + + device = devices[minor]; + + if (!device) { + pr_emerg("roccat device with minor %d doesn't exist\n", minor); + error = -ENODEV; + goto exit_err_devices; + } + + mutex_lock(&device->readers_lock); + + if (!device->open++) { + /* power on device on adding first reader */ + error = hid_hw_power(device->hid, PM_HINT_FULLON); + if (error < 0) { + --device->open; + goto exit_err_readers; + } + + error = hid_hw_open(device->hid); + if (error < 0) { + hid_hw_power(device->hid, PM_HINT_NORMAL); + --device->open; + goto exit_err_readers; + } + } + + reader->device = device; + /* new reader doesn't get old events */ + reader->cbuf_start = device->cbuf_end; + + list_add_tail(&reader->node, &device->readers); + file->private_data = reader; + +exit_err_readers: + mutex_unlock(&device->readers_lock); +exit_err_devices: + mutex_unlock(&devices_lock); + if (error) + kfree(reader); + return error; +} + +static int roccat_release(struct inode *inode, struct file *file) +{ + unsigned int minor = iminor(inode); + struct roccat_reader *reader = file->private_data; + struct roccat_device *device; + + mutex_lock(&devices_lock); + + device = devices[minor]; + if (!device) { + mutex_unlock(&devices_lock); + pr_emerg("roccat device with minor %d doesn't exist\n", minor); + return -ENODEV; + } + + mutex_lock(&device->readers_lock); + list_del(&reader->node); + mutex_unlock(&device->readers_lock); + kfree(reader); + + if (!--device->open) { + /* removing last reader */ + if (device->exist) { + hid_hw_power(device->hid, PM_HINT_NORMAL); + hid_hw_close(device->hid); + } else { + kfree(device); + } + } + + mutex_unlock(&devices_lock); + + return 0; +} + +/* + * roccat_report_event() - output data to readers + * @minor: minor device number returned by roccat_connect() + * @data: pointer to data + * + * Return value is zero on success, a negative error code on failure. + * + * This is called from interrupt handler. + */ +int roccat_report_event(int minor, u8 const *data) +{ + struct roccat_device *device; + struct roccat_reader *reader; + struct roccat_report *report; + uint8_t *new_value; + + device = devices[minor]; + + new_value = kmemdup(data, device->report_size, GFP_ATOMIC); + if (!new_value) + return -ENOMEM; + + report = &device->cbuf[device->cbuf_end]; + + /* passing NULL is safe */ + kfree(report->value); + + report->value = new_value; + device->cbuf_end = (device->cbuf_end + 1) % ROCCAT_CBUF_SIZE; + + list_for_each_entry(reader, &device->readers, node) { + /* + * As we already inserted one element, the buffer can't be + * empty. If start and end are equal, buffer is full and we + * increase start, so that slow reader misses one event, but + * gets the newer ones in the right order. + */ + if (reader->cbuf_start == device->cbuf_end) + reader->cbuf_start = (reader->cbuf_start + 1) % ROCCAT_CBUF_SIZE; + } + + wake_up_interruptible(&device->wait); + return 0; +} +EXPORT_SYMBOL_GPL(roccat_report_event); + +/* + * roccat_connect() - create a char device for special event output + * @class: the class thats used to create the device. Meant to hold device + * specific sysfs attributes. + * @hid: the hid device the char device should be connected to. + * @report_size: size of reports + * + * Return value is minor device number in Range [0, ROCCAT_MAX_DEVICES] on + * success, a negative error code on failure. + */ +int roccat_connect(struct class *klass, struct hid_device *hid, int report_size) +{ + unsigned int minor; + struct roccat_device *device; + int temp; + + device = kzalloc(sizeof(struct roccat_device), GFP_KERNEL); + if (!device) + return -ENOMEM; + + mutex_lock(&devices_lock); + + for (minor = 0; minor < ROCCAT_MAX_DEVICES; ++minor) { + if (devices[minor]) + continue; + break; + } + + if (minor < ROCCAT_MAX_DEVICES) { + devices[minor] = device; + } else { + mutex_unlock(&devices_lock); + kfree(device); + return -EINVAL; + } + + device->dev = device_create(klass, &hid->dev, + MKDEV(roccat_major, minor), NULL, + "%s%s%d", "roccat", hid->driver->name, minor); + + if (IS_ERR(device->dev)) { + devices[minor] = NULL; + mutex_unlock(&devices_lock); + temp = PTR_ERR(device->dev); + kfree(device); + return temp; + } + + mutex_unlock(&devices_lock); + + init_waitqueue_head(&device->wait); + INIT_LIST_HEAD(&device->readers); + mutex_init(&device->readers_lock); + mutex_init(&device->cbuf_lock); + device->minor = minor; + device->hid = hid; + device->exist = 1; + device->cbuf_end = 0; + device->report_size = report_size; + + return minor; +} +EXPORT_SYMBOL_GPL(roccat_connect); + +/* roccat_disconnect() - remove char device from hid device + * @minor: the minor device number returned by roccat_connect() + */ +void roccat_disconnect(int minor) +{ + struct roccat_device *device; + + mutex_lock(&devices_lock); + device = devices[minor]; + mutex_unlock(&devices_lock); + + device->exist = 0; /* TODO exist maybe not needed */ + + device_destroy(device->dev->class, MKDEV(roccat_major, minor)); + + mutex_lock(&devices_lock); + devices[minor] = NULL; + mutex_unlock(&devices_lock); + + if (device->open) { + hid_hw_close(device->hid); + wake_up_interruptible(&device->wait); + } else { + kfree(device); + } +} +EXPORT_SYMBOL_GPL(roccat_disconnect); + +static long roccat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct inode *inode = file_inode(file); + struct roccat_device *device; + unsigned int minor = iminor(inode); + long retval = 0; + + mutex_lock(&devices_lock); + + device = devices[minor]; + if (!device) { + retval = -ENODEV; + goto out; + } + + switch (cmd) { + case ROCCATIOCGREPSIZE: + if (put_user(device->report_size, (int __user *)arg)) + retval = -EFAULT; + break; + default: + retval = -ENOTTY; + } +out: + mutex_unlock(&devices_lock); + return retval; +} + +static const struct file_operations roccat_ops = { + .owner = THIS_MODULE, + .read = roccat_read, + .poll = roccat_poll, + .open = roccat_open, + .release = roccat_release, + .llseek = noop_llseek, + .unlocked_ioctl = roccat_ioctl, +}; + +static int __init roccat_init(void) +{ + int retval; + dev_t dev_id; + + retval = alloc_chrdev_region(&dev_id, ROCCAT_FIRST_MINOR, + ROCCAT_MAX_DEVICES, "roccat"); + + roccat_major = MAJOR(dev_id); + + if (retval < 0) { + pr_warn("can't get major number\n"); + goto error; + } + + cdev_init(&roccat_cdev, &roccat_ops); + retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES); + + if (retval < 0) { + pr_warn("cannot add cdev\n"); + goto cleanup_alloc_chrdev_region; + } + return 0; + + + cleanup_alloc_chrdev_region: + unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES); + error: + return retval; +} + +static void __exit roccat_exit(void) +{ + dev_t dev_id = MKDEV(roccat_major, 0); + + cdev_del(&roccat_cdev); + unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES); +} + +module_init(roccat_init); +module_exit(roccat_exit); + +MODULE_AUTHOR("Stefan Achatz"); +MODULE_DESCRIPTION("USB Roccat char device"); +MODULE_LICENSE("GPL v2"); |