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path: root/drivers/auxdisplay/ht16k33.c
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2019-08-20auxdisplay: ht16k33: Make ht16k33_fb_fix and ht16k33_fb_var constantNishka Dasgupta1-2/+2
The static structures ht16k33_fb_fix and ht16k33_fb_var, of types fb_fix_screeninfo and fb_var_screeninfo respectively, are not used except to be copied into other variables. Hence make both of them constant to prevent unintended modification. Issue found with Coccinelle. Acked-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2019-06-20auxdisplay/ht16k33.c: Convert to use vm_map_pages_zero()Souptick Joarder1-2/+2
While using mmap, the incorrect values of length and vm_pgoff are ignored and this driver goes ahead with mapping fbdev.buffer to user vma. Convert vm_insert_pages() to use vm_map_pages_zero(). We could later "fix" these drivers to behave according to the normal vm_pgoff offsetting simply by removing the _zero suffix on the function name and if that causes regressions, it gives us an easy way to revert. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Acked-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2019-02-15auxdisplay: ht16k33: fix potential user-after-free on module unloadMiguel Ojeda1-1/+1
On module unload/remove, we need to ensure that work does not run after we have freed resources. Concretely, cancel_delayed_work() may return while the callback function is still running. From kernel/workqueue.c: The work callback function may still be running on return, unless it returns true and the work doesn't re-arm itself. Explicitly flush or use cancel_delayed_work_sync() to wait on it. Link: https://lore.kernel.org/lkml/20190204220952.30761-1-TheSven73@googlemail.com/ Reported-by: Sven Van Asbroeck <thesven73@gmail.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Acked-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2018-04-12auxdisplay: Replace licenses with SPDX identifiersMiguel Ojeda1-9/+1
Cc: Philippe Ombredanne <pombredanne@nexb.com> Acked-by: Willy Tarreau <w@1wt.eu> Acked-by: Linus Walleij <triad@dflund.se> Acked-by: Robin van der Gracht <robin@protonic.nl> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2017-04-08auxdisplay: ht16k33: use le16_to_cpup() to fetch LE16 dataDmitry Torokhov1-4/+8
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>
2017-04-08auxdisplay: ht16k33: don't access uninitialized dataArnd Bergmann1-1/+7
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>
2017-02-10auxdisplay: ht16k33: remove private workqueueDmitry Torokhov1-15/+5
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>
2017-02-10auxdisplay: ht16k33: rework input device initializationDmitry Torokhov1-153/+145
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>
2017-02-10auxdisplay: ht16k33: do not try to free fbdevDmitry Torokhov1-3/+1
'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>
2016-11-10auxdisplay: ht16k33: Driver for LED controllerRobin van der Gracht1-0/+563
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>