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Message-ID: <201205081916.51659.hartleys@visionengravers.com>
Date: Tue, 8 May 2012 19:16:51 -0700
From: H Hartley Sweeten <hartleys@...ionengravers.com>
To: Linux Kernel <linux-kernel@...r.kernel.org>
CC: <devel@...verdev.osuosl.org>, <abbotti@....co.uk>,
<fmhess@...rs.sourceforge.net>, <gregkh@...uxfoundation.org>
Subject: [PATCH] staging: comedi: refactor sysfs files in comedi_fops.c
Refactor the sysfs attributes and functions to remove
the need for the forward declarations and use the
DEVICE_ATTR macro to define them.
Instead of individually creating sysfs device attribute
files, wrap them in an attribute_group and use the
sysfs_create_group function to create them.
Signed-off-by: H Hartley Sweeten <hsweeten@...ionengravers.com>
Cc: Ian Abbott <abbotti@....co.uk>
Cc: Mori Hess <fmhess@...rs.sourceforge.net>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 06fc656..e539f98 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -129,15 +129,295 @@ static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
static int comedi_fasync(int fd, struct file *file, int on);
static int is_device_busy(struct comedi_device *dev);
+
static int resize_async_buffer(struct comedi_device *dev,
struct comedi_subdevice *s,
- struct comedi_async *async, unsigned new_size);
+ struct comedi_async *async, unsigned new_size)
+{
+ int retval;
-/* declarations for sysfs attribute files */
-static struct device_attribute dev_attr_max_read_buffer_kb;
-static struct device_attribute dev_attr_read_buffer_kb;
-static struct device_attribute dev_attr_max_write_buffer_kb;
-static struct device_attribute dev_attr_write_buffer_kb;
+ if (new_size > async->max_bufsize)
+ return -EPERM;
+
+ if (s->busy) {
+ DPRINTK("subdevice is busy, cannot resize buffer\n");
+ return -EBUSY;
+ }
+ if (async->mmap_count) {
+ DPRINTK("subdevice is mmapped, cannot resize buffer\n");
+ return -EBUSY;
+ }
+
+ if (!async->prealloc_buf)
+ return -EINVAL;
+
+ /* make sure buffer is an integral number of pages
+ * (we round up) */
+ new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
+
+ retval = comedi_buf_alloc(dev, s, new_size);
+ if (retval < 0)
+ return retval;
+
+ if (s->buf_change) {
+ retval = s->buf_change(dev, s, new_size);
+ if (retval < 0)
+ return retval;
+ }
+
+ DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
+ dev->minor, (int)(s - dev->subdevices), async->prealloc_bufsz);
+ return 0;
+}
+
+/* sysfs attribute files */
+
+static const unsigned bytes_per_kibi = 1024;
+
+static ssize_t show_max_read_buffer_kb(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned max_buffer_size_kb = 0;
+ struct comedi_subdevice *const read_subdevice =
+ comedi_get_read_subdevice(info);
+
+ mutex_lock(&info->device->mutex);
+ if (read_subdevice &&
+ (read_subdevice->subdev_flags & SDF_CMD_READ) &&
+ read_subdevice->async) {
+ max_buffer_size_kb = read_subdevice->async->max_bufsize /
+ bytes_per_kibi;
+ }
+ retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
+ mutex_unlock(&info->device->mutex);
+
+ return retval;
+}
+
+static ssize_t store_max_read_buffer_kb(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned int new_max_size_kb;
+ unsigned int new_max_size;
+ int ret;
+ struct comedi_subdevice *const read_subdevice =
+ comedi_get_read_subdevice(info);
+
+ ret = kstrtouint(buf, 10, &new_max_size_kb);
+ if (ret)
+ return ret;
+ if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
+ return -EINVAL;
+ new_max_size = new_max_size_kb * bytes_per_kibi;
+
+ mutex_lock(&info->device->mutex);
+ if (read_subdevice == NULL ||
+ (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
+ read_subdevice->async == NULL) {
+ mutex_unlock(&info->device->mutex);
+ return -EINVAL;
+ }
+ read_subdevice->async->max_bufsize = new_max_size;
+ mutex_unlock(&info->device->mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR(max_read_buffer_kb, S_IRUGO | S_IWUSR,
+ show_max_read_buffer_kb, store_max_read_buffer_kb);
+
+static ssize_t show_read_buffer_kb(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned buffer_size_kb = 0;
+ struct comedi_subdevice *const read_subdevice =
+ comedi_get_read_subdevice(info);
+
+ mutex_lock(&info->device->mutex);
+ if (read_subdevice &&
+ (read_subdevice->subdev_flags & SDF_CMD_READ) &&
+ read_subdevice->async) {
+ buffer_size_kb = read_subdevice->async->prealloc_bufsz /
+ bytes_per_kibi;
+ }
+ retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
+ mutex_unlock(&info->device->mutex);
+
+ return retval;
+}
+
+static ssize_t store_read_buffer_kb(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned int new_size_kb;
+ unsigned int new_size;
+ int retval;
+ int ret;
+ struct comedi_subdevice *const read_subdevice =
+ comedi_get_read_subdevice(info);
+
+ ret = kstrtouint(buf, 10, &new_size_kb);
+ if (ret)
+ return ret;
+ if (new_size_kb > (UINT_MAX / bytes_per_kibi))
+ return -EINVAL;
+ new_size = new_size_kb * bytes_per_kibi;
+
+ mutex_lock(&info->device->mutex);
+ if (read_subdevice == NULL ||
+ (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
+ read_subdevice->async == NULL) {
+ mutex_unlock(&info->device->mutex);
+ return -EINVAL;
+ }
+ retval = resize_async_buffer(info->device, read_subdevice,
+ read_subdevice->async, new_size);
+ mutex_unlock(&info->device->mutex);
+
+ if (retval < 0)
+ return retval;
+ return count;
+}
+
+static DEVICE_ATTR(read_buffer_kb, S_IRUGO | S_IWUSR | S_IWGRP,
+ show_read_buffer_kb, store_read_buffer_kb);
+
+static ssize_t show_max_write_buffer_kb(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t retval;
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned max_buffer_size_kb = 0;
+ struct comedi_subdevice *const write_subdevice =
+ comedi_get_write_subdevice(info);
+
+ mutex_lock(&info->device->mutex);
+ if (write_subdevice &&
+ (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
+ write_subdevice->async) {
+ max_buffer_size_kb = write_subdevice->async->max_bufsize /
+ bytes_per_kibi;
+ }
+ retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
+ mutex_unlock(&info->device->mutex);
+
+ return retval;
+}
+
+static ssize_t store_max_write_buffer_kb(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned int new_max_size_kb;
+ unsigned int new_max_size;
+ int ret;
+ struct comedi_subdevice *const write_subdevice =
+ comedi_get_write_subdevice(info);
+
+ ret = kstrtouint(buf, 10, &new_max_size_kb);
+ if (ret)
+ return ret;
+ if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
+ return -EINVAL;
+ new_max_size = new_max_size_kb * bytes_per_kibi;
+
+ mutex_lock(&info->device->mutex);
+ if (write_subdevice == NULL ||
+ (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
+ write_subdevice->async == NULL) {
+ mutex_unlock(&info->device->mutex);
+ return -EINVAL;
+ }
+ write_subdevice->async->max_bufsize = new_max_size;
+ mutex_unlock(&info->device->mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR(max_write_buffer_kb, S_IRUGO | S_IWUSR,
+ show_max_write_buffer_kb, store_max_write_buffer_kb);
+
+static ssize_t show_write_buffer_kb(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned buffer_size_kb = 0;
+ struct comedi_subdevice *const write_subdevice =
+ comedi_get_write_subdevice(info);
+
+ mutex_lock(&info->device->mutex);
+ if (write_subdevice &&
+ (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
+ write_subdevice->async) {
+ buffer_size_kb = write_subdevice->async->prealloc_bufsz /
+ bytes_per_kibi;
+ }
+ retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
+ mutex_unlock(&info->device->mutex);
+
+ return retval;
+}
+
+static ssize_t store_write_buffer_kb(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct comedi_device_file_info *info = dev_get_drvdata(dev);
+ unsigned int new_size_kb;
+ unsigned int new_size;
+ int retval;
+ int ret;
+ struct comedi_subdevice *const write_subdevice =
+ comedi_get_write_subdevice(info);
+
+ ret = kstrtouint(buf, 10, &new_size_kb);
+ if (ret)
+ return ret;
+ if (new_size_kb > (UINT_MAX / bytes_per_kibi))
+ return -EINVAL;
+ new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
+
+ mutex_lock(&info->device->mutex);
+ if (write_subdevice == NULL ||
+ (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
+ write_subdevice->async == NULL) {
+ mutex_unlock(&info->device->mutex);
+ return -EINVAL;
+ }
+ retval = resize_async_buffer(info->device, write_subdevice,
+ write_subdevice->async, new_size);
+ mutex_unlock(&info->device->mutex);
+
+ if (retval < 0)
+ return retval;
+ return count;
+}
+
+static DEVICE_ATTR(write_buffer_kb, S_IRUGO | S_IWUSR | S_IWGRP,
+ show_write_buffer_kb, store_write_buffer_kb);
+
+static struct attribute *comedi_attrs[] = {
+ &dev_attr_max_read_buffer_kb.attr,
+ &dev_attr_read_buffer_kb.attr,
+ &dev_attr_max_write_buffer_kb.attr,
+ &dev_attr_write_buffer_kb.attr,
+ NULL
+};
+
+static const struct attribute_group comedi_sysfs_files = {
+ .attrs = comedi_attrs,
+};
static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
@@ -2251,42 +2531,15 @@ int comedi_alloc_board_minor(struct device *hardware_device)
if (!IS_ERR(csdev))
info->device->class_dev = csdev;
dev_set_drvdata(csdev, info);
- retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
+
+ retval = sysfs_create_group(&csdev->kobj, &comedi_sysfs_files);
if (retval) {
printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_max_read_buffer_kb.attr.name);
- comedi_free_board_minor(i);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_read_buffer_kb.attr.name);
- comedi_free_board_minor(i);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_max_write_buffer_kb.attr.name);
- comedi_free_board_minor(i);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_write_buffer_kb.attr.name);
+ "comedi: failed to create sysfs attribute files\n");
comedi_free_board_minor(i);
return retval;
}
+
return i;
}
@@ -2367,42 +2620,15 @@ int comedi_alloc_subdevice_minor(struct comedi_device *dev,
if (!IS_ERR(csdev))
s->class_dev = csdev;
dev_set_drvdata(csdev, info);
- retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
+
+ retval = sysfs_create_group(&csdev->kobj, &comedi_sysfs_files);
if (retval) {
printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_max_read_buffer_kb.attr.name);
- comedi_free_subdevice_minor(s);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_read_buffer_kb.attr.name);
- comedi_free_subdevice_minor(s);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_max_write_buffer_kb.attr.name);
- comedi_free_subdevice_minor(s);
- return retval;
- }
- retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
- if (retval) {
- printk(KERN_ERR
- "comedi: "
- "failed to create sysfs attribute file \"%s\".\n",
- dev_attr_write_buffer_kb.attr.name);
- comedi_free_subdevice_minor(s);
+ "comedi: failed to create sysfs attribute files\n");
+ comedi_free_board_minor(i);
return retval;
}
+
return i;
}
@@ -2441,300 +2667,3 @@ struct comedi_device_file_info *comedi_get_device_file_info(unsigned minor)
return info;
}
EXPORT_SYMBOL_GPL(comedi_get_device_file_info);
-
-static int resize_async_buffer(struct comedi_device *dev,
- struct comedi_subdevice *s,
- struct comedi_async *async, unsigned new_size)
-{
- int retval;
-
- if (new_size > async->max_bufsize)
- return -EPERM;
-
- if (s->busy) {
- DPRINTK("subdevice is busy, cannot resize buffer\n");
- return -EBUSY;
- }
- if (async->mmap_count) {
- DPRINTK("subdevice is mmapped, cannot resize buffer\n");
- return -EBUSY;
- }
-
- if (!async->prealloc_buf)
- return -EINVAL;
-
- /* make sure buffer is an integral number of pages
- * (we round up) */
- new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
-
- retval = comedi_buf_alloc(dev, s, new_size);
- if (retval < 0)
- return retval;
-
- if (s->buf_change) {
- retval = s->buf_change(dev, s, new_size);
- if (retval < 0)
- return retval;
- }
-
- DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
- dev->minor, (int)(s - dev->subdevices), async->prealloc_bufsz);
- return 0;
-}
-
-/* sysfs attribute files */
-
-static const unsigned bytes_per_kibi = 1024;
-
-static ssize_t show_max_read_buffer_kb(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- ssize_t retval;
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned max_buffer_size_kb = 0;
- struct comedi_subdevice *const read_subdevice =
- comedi_get_read_subdevice(info);
-
- mutex_lock(&info->device->mutex);
- if (read_subdevice &&
- (read_subdevice->subdev_flags & SDF_CMD_READ) &&
- read_subdevice->async) {
- max_buffer_size_kb = read_subdevice->async->max_bufsize /
- bytes_per_kibi;
- }
- retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
- mutex_unlock(&info->device->mutex);
-
- return retval;
-}
-
-static ssize_t store_max_read_buffer_kb(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned int new_max_size_kb;
- unsigned int new_max_size;
- int ret;
- struct comedi_subdevice *const read_subdevice =
- comedi_get_read_subdevice(info);
-
- ret = kstrtouint(buf, 10, &new_max_size_kb);
- if (ret)
- return ret;
- if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
- return -EINVAL;
- new_max_size = new_max_size_kb * bytes_per_kibi;
-
- mutex_lock(&info->device->mutex);
- if (read_subdevice == NULL ||
- (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
- read_subdevice->async == NULL) {
- mutex_unlock(&info->device->mutex);
- return -EINVAL;
- }
- read_subdevice->async->max_bufsize = new_max_size;
- mutex_unlock(&info->device->mutex);
-
- return count;
-}
-
-static struct device_attribute dev_attr_max_read_buffer_kb = {
- .attr = {
- .name = "max_read_buffer_kb",
- .mode = S_IRUGO | S_IWUSR},
- .show = &show_max_read_buffer_kb,
- .store = &store_max_read_buffer_kb
-};
-
-static ssize_t show_read_buffer_kb(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- ssize_t retval;
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned buffer_size_kb = 0;
- struct comedi_subdevice *const read_subdevice =
- comedi_get_read_subdevice(info);
-
- mutex_lock(&info->device->mutex);
- if (read_subdevice &&
- (read_subdevice->subdev_flags & SDF_CMD_READ) &&
- read_subdevice->async) {
- buffer_size_kb = read_subdevice->async->prealloc_bufsz /
- bytes_per_kibi;
- }
- retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
- mutex_unlock(&info->device->mutex);
-
- return retval;
-}
-
-static ssize_t store_read_buffer_kb(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned int new_size_kb;
- unsigned int new_size;
- int retval;
- int ret;
- struct comedi_subdevice *const read_subdevice =
- comedi_get_read_subdevice(info);
-
- ret = kstrtouint(buf, 10, &new_size_kb);
- if (ret)
- return ret;
- if (new_size_kb > (UINT_MAX / bytes_per_kibi))
- return -EINVAL;
- new_size = new_size_kb * bytes_per_kibi;
-
- mutex_lock(&info->device->mutex);
- if (read_subdevice == NULL ||
- (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
- read_subdevice->async == NULL) {
- mutex_unlock(&info->device->mutex);
- return -EINVAL;
- }
- retval = resize_async_buffer(info->device, read_subdevice,
- read_subdevice->async, new_size);
- mutex_unlock(&info->device->mutex);
-
- if (retval < 0)
- return retval;
- return count;
-}
-
-static struct device_attribute dev_attr_read_buffer_kb = {
- .attr = {
- .name = "read_buffer_kb",
- .mode = S_IRUGO | S_IWUSR | S_IWGRP},
- .show = &show_read_buffer_kb,
- .store = &store_read_buffer_kb
-};
-
-static ssize_t show_max_write_buffer_kb(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- ssize_t retval;
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned max_buffer_size_kb = 0;
- struct comedi_subdevice *const write_subdevice =
- comedi_get_write_subdevice(info);
-
- mutex_lock(&info->device->mutex);
- if (write_subdevice &&
- (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
- write_subdevice->async) {
- max_buffer_size_kb = write_subdevice->async->max_bufsize /
- bytes_per_kibi;
- }
- retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
- mutex_unlock(&info->device->mutex);
-
- return retval;
-}
-
-static ssize_t store_max_write_buffer_kb(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned int new_max_size_kb;
- unsigned int new_max_size;
- int ret;
- struct comedi_subdevice *const write_subdevice =
- comedi_get_write_subdevice(info);
-
- ret = kstrtouint(buf, 10, &new_max_size_kb);
- if (ret)
- return ret;
- if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
- return -EINVAL;
- new_max_size = new_max_size_kb * bytes_per_kibi;
-
- mutex_lock(&info->device->mutex);
- if (write_subdevice == NULL ||
- (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
- write_subdevice->async == NULL) {
- mutex_unlock(&info->device->mutex);
- return -EINVAL;
- }
- write_subdevice->async->max_bufsize = new_max_size;
- mutex_unlock(&info->device->mutex);
-
- return count;
-}
-
-static struct device_attribute dev_attr_max_write_buffer_kb = {
- .attr = {
- .name = "max_write_buffer_kb",
- .mode = S_IRUGO | S_IWUSR},
- .show = &show_max_write_buffer_kb,
- .store = &store_max_write_buffer_kb
-};
-
-static ssize_t show_write_buffer_kb(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- ssize_t retval;
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned buffer_size_kb = 0;
- struct comedi_subdevice *const write_subdevice =
- comedi_get_write_subdevice(info);
-
- mutex_lock(&info->device->mutex);
- if (write_subdevice &&
- (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
- write_subdevice->async) {
- buffer_size_kb = write_subdevice->async->prealloc_bufsz /
- bytes_per_kibi;
- }
- retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
- mutex_unlock(&info->device->mutex);
-
- return retval;
-}
-
-static ssize_t store_write_buffer_kb(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct comedi_device_file_info *info = dev_get_drvdata(dev);
- unsigned int new_size_kb;
- unsigned int new_size;
- int retval;
- int ret;
- struct comedi_subdevice *const write_subdevice =
- comedi_get_write_subdevice(info);
-
- ret = kstrtouint(buf, 10, &new_size_kb);
- if (ret)
- return ret;
- if (new_size_kb > (UINT_MAX / bytes_per_kibi))
- return -EINVAL;
- new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
-
- mutex_lock(&info->device->mutex);
- if (write_subdevice == NULL ||
- (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
- write_subdevice->async == NULL) {
- mutex_unlock(&info->device->mutex);
- return -EINVAL;
- }
- retval = resize_async_buffer(info->device, write_subdevice,
- write_subdevice->async, new_size);
- mutex_unlock(&info->device->mutex);
-
- if (retval < 0)
- return retval;
- return count;
-}
-
-static struct device_attribute dev_attr_write_buffer_kb = {
- .attr = {
- .name = "write_buffer_kb",
- .mode = S_IRUGO | S_IWUSR | S_IWGRP},
- .show = &show_write_buffer_kb,
- .store = &store_write_buffer_kb
-};
--
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