auxdisplay: ht16k33: use le16_to_cpup() to fetch LE16 data

The data read from the device is 3 little-endian words, so let's
annotate them as such and use le16_to_cpu() to convert them to host
endian

auxdisplay: ht16k33: use le16_to_cpup() to fetch LE16 data

The data read from the device is 3 little-endian words, so let's
annotate them as such and use le16_to_cpu() to convert them to host
endianness - it might turn out to be a bit more performant, and it
expresses the conversion more clearly.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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auxdisplay: ht16k33: don't access uninitialized data

gcc-7.0.1 points out that we copy uninitialized data from the stack
into a per-device structure:

drivers/auxdisplay/ht16k33.c: In function 'ht16

auxdisplay: ht16k33: don't access uninitialized data

gcc-7.0.1 points out that we copy uninitialized data from the stack
into a per-device structure:

drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread':
arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used uninitialized in this function [-Werror=maybe-uninitialized]
arch/x86/include/asm/string_32.h:79:22: error: '*((void *)&new_state+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The access is harmless because we never read the data, but we are better
off not doing this, so this changes the code to only copy the data
that was actually initialized. To make sure we don't overflow the
stack with an incorrect DT, we also need to add a sanity checkin the
probe function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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auxdisplay: ht16k33: remove private workqueue

There is no need for the driver to use private workqueue, standard system
workqueue should suffice as they are going to use the same worker pool
anyway.

auxdisplay: ht16k33: remove private workqueue

There is no need for the driver to use private workqueue, standard system
workqueue should suffice as they are going to use the same worker pool
anyway.

Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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auxdisplay: ht16k33: rework input device initialization

This patch fixes following issues in input device (keypad) handling:

- requesting IRQ before allocating and initializing parts of the device

auxdisplay: ht16k33: rework input device initialization

This patch fixes following issues in input device (keypad) handling:

- requesting IRQ before allocating and initializing parts of the device
that can be referenced from IRQ handler is racy, even if we try to
disable interrupt after requesting it. Let's move allocations around
so that everything is ready by the time we request IRQ.

- using threaded interrupt handler to schedule a work item it sub-optimal.
Disabling and then re-enabling interrupts in work item and in open/close
methods is prone to races and exactly the reason theraded interrupts were
introduced. Let's use the infrastructure properly and keep scanning the
matrix array in IRQ thread, stopping when there are no keys, or when told
to do so.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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auxdisplay: ht16k33: do not try to free fbdev

'fbdev' is allocated as part of larger ht16k33_priv structure; trying to
free it will cause troubles.

Acked-by: Robin van der Gracht <robin@protonic.nl

auxdisplay: ht16k33: do not try to free fbdev

'fbdev' is allocated as part of larger ht16k33_priv structure; trying to
free it will cause troubles.

Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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auxdisplay: ht16k33: Driver for LED controller

Added a driver for the Holtek HT16K33 LED controller with keyscan.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
CC: Miguel Ojeda Sandonis <

auxdisplay: ht16k33: Driver for LED controller

Added a driver for the Holtek HT16K33 LED controller with keyscan.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
CC: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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