Pull spi uaccess delousing from Al Viro:
 "Getting rid of pointless __get_user() and friends in drivers/spi.

  [ the only reason it's on a separate branch is that I hoped it would
    be picked by spi folks; looks like mail asking them to grab it got
    lost and I hadn't followed up on that ]"

* 'for-spi' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  spidev: quit messing with access_ok()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

This removes an unused completion from spidev_sync.

It was introduced in

	commit 25d5cb4b0375e ("spi: remove some spidev oops-on-rmmod paths")

and it was no longer used after:

	commit 98d6f47958001 ("spi: spidev: use spi_sync instead of spi_async")

Signed-off-by: Seraphime Kirkovski (Haapie) <kirkseraph@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

Add entry for the semtech sx1301 baseband processor implementing a LoRa
concentrator IP.
At this time this chip requires an spidev userspace driver.

Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Steve deRosier <derosier@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Entries are needed in the spidev ID list to configure configure it from a
device tree. Add entry for the following device:
- "ge,achc" :  GE Healthcare USB Management Controller

The USB Management Controller does not expose USB to the host, but acts as
an offload engine, communicating with specific USB based data acquisition
devices which are connected to it, extracting the required data and
providing it to the host via other methods. SPI is used as an out-of-band
configuration channel.

Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

Some IoT and maker software stacks are using spidev to perform raw access
to the SPI bus instead of relying existing drivers provided by the kernel.
They then implement their own "drivers" in userspace on top of the spidev
raw interface. This is far from being an ideal solution but we do not want
to prevent using mainline Linux in these devices.

Now, it turns out that Windows has similar SPI devices than spidev which
allow raw access on the SPI bus to userspace programs as described in the
link below:

  https://msdn.microsoft.com/windows/hardware/drivers/spb/spi-tests-in-mitt

These SPI test devices are also meant to be used during development and
testing.

In order to allow usage of spidev for development and testing in Linux, add
those same ACPI IDs to the spidev driver (which is Linux counterpart of the
Windows SPI test devices), but complain loudly so that users know it is not
good idea to use it in production systems. Instead they should be using
proper drivers for peripherals connected to the SPI bus.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

We use the spi_lock spinlock to protect against races between the device
being removed and file operations on the spidev.  This means that in the
removal path all references to the device need to be done under lock as
in removal we dropping references to the device.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

On 64-bit with CONFIG_SPI_DEBUG=y and #define VERBOSE:

    drivers/spi/spidev.c:287:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 4 has type '__u32' [-Wformat=]

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>