While e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no
interrupt") added support for using uio_pdrv_genirq for devices without
interrupt for device tree platforms, the removal of uio_pdrv in
26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead")
broke the support for non device tree platforms.

This change fixes this, so that uio_pdrv_genirq can be used without
interrupt on all platforms.

This still leaves the support that uio_pdrv had for custom interrupt
handler lacking, as uio_pdrv_genirq does not handle it (yet).

Fixes: 26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200701145659.3978-3-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no
interrupt"), the uio_pdrv_genirq has supported use without interrupt,
so the change in 7723f4c5ecdb ("driver core: platform: Add an error
message to") added false warnings for those cases.

Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200701145659.3978-2-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver calls sysfs_create_bin_file() in probe, but forgets to
call sysfs_remove_bin_file() in remove.
Add the missed call to fix it.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20200507151343.792816-1-hslester96@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the following coccicheck warning:

drivers/uio/uio_dmem_genirq.c:47:5-8: Unneeded variable: "ret". Return
"0" on line 71

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200428063155.42349-1-yanaijie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200425124448.139532-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change makes use of the new devm_uio_register_device() initializer.
This cleans up the exit path quite nicely, and removes the remove function
of the driver.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200306161853.25368-2-alexandru.ardelean@analog.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change adds a resource managed equivalent of uio_register_device().
Not adding devm_uio_unregister_device(), since the intent is to discourage
it's usage. Having such a function may allow some bad driver designs. Most
users of devm_*register*() functions rarely use the unregister equivalents.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200306161853.25368-1-alexandru.ardelean@analog.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When deferring the probe routine just return without displaying an
error.

Signed-off-by: Oscar Ravadilla <oscar.ravadilla@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20200108001648.2949-1-oscar.ravadilla@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:

kernel/irq/manage.c, 523:
	synchronize_irq in disable_irq
drivers/uio/uio_dmem_genirq.c, 140:
	disable_irq in uio_dmem_genirq_irqcontrol
drivers/uio/uio_dmem_genirq.c, 134:
	_raw_spin_lock_irqsave in uio_dmem_genirq_irqcontrol

synchronize_irq() can sleep at runtime.

To fix this bug, disable_irq() is called without holding the spinlock.

This bug is found by a static analysis tool STCheck written by myself.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20191218094405.6009-1-baijiaju1990@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change also does a bit of a unification for the IRQ init code.

But the actual problem is that UIO_IRQ_NONE == 0, so for the DT case where
UIO_IRQ_NONE gets assigned to `uioinfo->irq`, a 2nd initialization will get
triggered (for the IRQ) and this one will exit via `goto bad1`.

As far as things seem to go, the only case where UIO_IRQ_NONE seems valid,
is when using a device-tree. The driver has some legacy support for old
platform_data structures. It looks like, for platform_data a non-existent
IRQ is an invalid case (or was considered an invalid case).
Which is why -ENXIO is treated only when a DT is used.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Acked-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>
Link: https://lore.kernel.org/r/20191105073212.16719-1-alexandru.ardelean@analog.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>