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>
If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.
Export the module alias information using the MODULE_DEVICE_TABLE() macro.
Before this patch:
$ modinfo drivers/auxdisplay/img-ascii-lcd.ko | grep alias
$
After this patch:
$ modinfo drivers/auxdisplay/img-ascii-lcd.ko | grep alias
alias: of:N*T*Cmti,sead3-lcdC*
alias: of:N*T*Cmti,sead3-lcd
alias: of:N*T*Cmti,malta-lcdC*
alias: of:N*T*Cmti,malta-lcd
alias: of:N*T*Cimg,boston-lcdC*
alias: of:N*T*Cimg,boston-lcd
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
DT properties specifying physical properties should contain appropriate
suffices indicating the units of measurement.
Hence amend the HD44780 DT bindings to add "chars" suffixes to the
"display-height" and "display-width" properties, and update the driver
to parse them.
Fixes: dd9502a9e9 ("dt-bindings: auxdisplay: Add bindings for Hitachi HD44780")
Fixes: d47d88361f ("auxdisplay: Add HD44780 Character LCD support")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Hitachi HD44780 Character LCD Controller is commonly used on
character LCDs that can display one or more lines of text.
This driver supports character LCDs connected to GPIOs, using either a
4-bit or 8-bit data bus, and provides access through the charlcd core
and /dev/lcd.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On displays with more than two lines, the additional lines are stored in
the buffers used for the first two lines, but beyond the visible parts.
Adjust the DDRAM address calculation to cater for this.
When clearing the display, avoid writing more spaces than the actual
size of the physical buffer.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In 4-bit mode, 8-bit commands and data are written using two raw writes
to the data interface: high nibble first, low nibble last. This must be
handled by the low-level driver.
However, as we don't know in which mode (4-bit or 8-bit) nor 4-bit phase
the LCD was left, initialization must always be handled using raw
writes, and needs to configure the LCD for 8-bit mode first.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Extract the character LCD core from the Parallel port LCD/Keypad Panel
driver in the misc subsystem, and convert it into a subdriver in the
auxdisplay subsystem. This allows the character LCD core to be used by
other drivers later.
Compilation is controlled by its own Kconfig symbol CHARLCD, which is to
be selected by its users, but can be enabled manually for
compile-testing.
All functions changed their prefix from "lcd_" to "charlcd_", and gained
a "struct charlcd *" parameter to operate on a specific instance.
While the driver API thus is ready to support multiple instances, the
current limitation of a single display (/dev/lcd has a single misc minor
assigned) is retained.
No functional changes intended.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
'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>
The new driver caused a rare randconfig failure:
drivers/auxdisplay/ht16k33.o:(.data.ht16k33_fb_ops+0xc): undefined reference to `fb_sys_read'
drivers/auxdisplay/ht16k33.o:(.data.ht16k33_fb_ops+0x10): undefined reference to `fb_sys_write'
This selects the respective helper modules.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a driver for simple ASCII LCD displays found on the MIPS Boston,
Malta & SEAD3 development boards. The Boston display is an independent
memory mapped device with a simple memory mapped 8 byte register space
containing the 8 ASCII characters to display. The Malta display is
exposed as part of the Malta board registers, and provides 8 registers
each of which corresponds to one of the ASCII characters to display. The
SEAD3 display is slightly more complex, exposing an interface to an
S6A0069 LCD controller via registers provided by the boards CPLD.
However although the displays differ in their register interface, we
require similar functionality on each board so abstracting away the
differences within a single driver allows us to share a significant
amount of code & ensure consistent behaviour.
The driver displays the Linux kernel version as the default message, but
allows the message to be changed via a character device. Messages longer
then the number of characters that the display can show will scroll.
This provides different behaviour to the existing LCD display code for
the MIPS Malta or MIPS SEAD3 platforms in the following ways:
- The default string to display is not "LINUX ON MALTA" or "LINUX ON
SEAD3" but "Linux" followed by the version number of the kernel
(UTS_RELEASE).
- Since that string tends to be significantly longer it scrolls twice
as fast, moving every 500ms rather than every 1s.
- The LCD won't be updated until the driver is probed, so it doesn't
provide the early "LINUX" string.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14062/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The local variable ks0108_parport is used by other functions to write to
the parallel port. We missed initializing it when we converted the
driver to use new Parallel Port codes.
Fixes: 4edd70c133 ("auxdisplay: ks0108: use new parport device model")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Start using pr_* macros instead of using printk and in the process
define pr_fmt.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parport_find_base() will implicitly do parport_get_port() which
increases the refcount. Then parport_register_device() will again
increment the refcount. But while unloading the module we are only
doing parport_unregister_device() decrementing the refcount only once.
We add an parport_put_port() to neutralize the effect of
parport_get_port().
Cc: <stable@vger.kernel.org> # 2.6.32+
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wei Yongjun
Andy Shevchenko
Dmitry Torokhov
Javier Martinez Canillas
Arnd Bergmann
Geert Uytterhoeven
Greg Kroah-Hartman
Randy Dunlap
Robin van der Gracht
Paul Burton
Sudip Mukherjee