From 328a14e70e7f46997cb50d4258dd93d5377f98c6 Mon Sep 17 00:00:00 2001 From: "Hans J. Koch" Date: Fri, 23 May 2008 13:50:14 +0200 Subject: UIO: Add write function to allow irq masking MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sometimes it is necessary to enable/disable the interrupt of a UIO device from the userspace part of the driver. With this patch, the UIO kernel driver can implement an "irqcontrol()" function that does this. Userspace can write an s32 value to /dev/uioX (usually 0 or 1 to turn the irq off or on). The UIO core will then call the driver's irqcontrol function. Signed-off-by: Hans J. Koch Acked-by: Uwe Kleine-König Acked-by: Magnus Damm Signed-off-by: Greg Kroah-Hartman --- drivers/uio/uio.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/uio') diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 5a7ca2e6094..3a6934bf713 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -427,6 +427,31 @@ static ssize_t uio_read(struct file *filep, char __user *buf, return retval; } +static ssize_t uio_write(struct file *filep, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct uio_listener *listener = filep->private_data; + struct uio_device *idev = listener->dev; + ssize_t retval; + s32 irq_on; + + if (idev->info->irq == UIO_IRQ_NONE) + return -EIO; + + if (count != sizeof(s32)) + return -EINVAL; + + if (!idev->info->irqcontrol) + return -ENOSYS; + + if (copy_from_user(&irq_on, buf, count)) + return -EFAULT; + + retval = idev->info->irqcontrol(idev->info, irq_on); + + return retval ? retval : sizeof(s32); +} + static int uio_find_mem_index(struct vm_area_struct *vma) { int mi; @@ -546,6 +571,7 @@ static const struct file_operations uio_fops = { .open = uio_open, .release = uio_release, .read = uio_read, + .write = uio_write, .mmap = uio_mmap, .poll = uio_poll, .fasync = uio_fasync, -- cgit v1.2.3-18-g5258