Messages in this thread | | | From | Alexander Stein <> | Subject | Re: [PATCH 3/6 v14] gpio: Add userland device interface to block GPIO | Date | Thu, 24 Jan 2013 10:13:40 +0100 |
| |
On Tuesday 22 January 2013 13:06:41, Roland Stigge wrote: > This patch adds a character device interface to the block GPIO system. > > Signed-off-by: Roland Stigge <stigge@antcom.de> > --- > Documentation/ABI/testing/dev-gpioblock | 34 ++++ > drivers/gpio/gpiolib.c | 225 +++++++++++++++++++++++++++++++- > include/linux/gpio.h | 13 + > 3 files changed, 271 insertions(+), 1 deletion(-) > > --- /dev/null > +++ linux-2.6/Documentation/ABI/testing/dev-gpioblock > @@ -0,0 +1,34 @@ > +What: /dev/<gpioblock> > +Date: Nov 2012 > +KernelVersion: 3.7 > +Contact: Roland Stigge <stigge@antcom.de> > +Description: The /dev/<gpioblock> character device node provides userspace > + access to GPIO blocks, named exactly as the block, e.g. > + /dev/block0. > + > + Reading: > + When reading sizeof(unsigned long) bytes from the device, the > + current state of the block, masked by the current mask (see > + below) can be obtained as a word. When the device is opened > + with O_NONBLOCK, read() always returns with data immediately, > + otherwise it blocks until data is available, see IRQ handling > + below. > + > + Writing: > + By writing sizeof(unsigned long) bytes to the device, the > + current state of the block can be set. This operation is > + masked by the current mask (see below). > + > + IRQ handling: > + When one or more IRQs in the block are IRQ capable, you can ^^^^ I think this should be GPIOs
> +static long gpio_block_fop_ioctl(struct file *f, unsigned int cmd, > + unsigned long arg) > +{ > + struct gpio_block *block = (struct gpio_block *)f->private_data; > + unsigned long __user *x = (unsigned long __user *)arg; > + > + if (cmd == 0) > + return get_user(block->cur_mask, x); > + > + return -EINVAL; > +}
So there is no way from userspace to create/remove GPIO blocks? I know support in sysfs is problematic due to formatting, but an IOCTL for that would be nice.
Best regards, Alexander
| |