Commit Graph

8 Commits

Author SHA1 Message Date
Colin Ian King 413f9e9918 gpio: make several const arrays static, shrinks object size
Don't populate the const read-only arrays 'port' on the stack but
instead make them static. Makes the object code smaller:

Before:
  text    data     bss     dec    hex filename
  8542    4088     672   13302   33f6 drivers/gpio/gpio-gpio-mm.o
 10959    4952     832   16743   4167 drivers/gpio/gpio-104-dio-48e.o
  9022    5064    1408   15494   3c86 drivers/gpio/gpio-104-idi-48.o

After:
  text    data     bss     dec    hex filename
  8372    4144     672   13188   3384 drivers/gpio/gpio-gpio-mm.o
 10790    5008     832   16630   40f6 drivers/gpio/gpio-104-dio-48e.o
  8853    5152    1408   15413   3c35 linux/drivers/gpio/gpio-104-idi-48.o

(gcc version 7.2.0 x86_64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-05-16 14:35:24 +02:00
William Breathitt Gray 41b251318a gpio: gpio-mm: Implement get_multiple callback
The Diamond Systems GPIO-MM series of devices contain two 82C55A
devices, which each feature three 8-bit ports of I/O. Since eight input
lines are acquired on a single port input read, the GPIO-MM GPIO driver
may improve multiple input reads by utilizing a get_multiple callback.
This patch implements the gpiomm_gpio_get_multiple function which serves
as the respective get_multiple callback.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-03-26 10:27:31 +02:00
David Howells d759f90679 Annotate hardware config module parameters in drivers/gpio/
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify.  The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in drivers/gpio/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
cc: Alexandre Courbot <gnurou@gmail.com>
cc: linux-gpio@vger.kernel.org
2017-04-20 12:02:32 +01:00
William Breathitt Gray 210b4bde5f gpio: gpio-mm: Add support for GPIO names
This patch sets the gpio_chip names option with an array of GPIO line
names that match the manual documentation for the Diamond Systems
GPIO-MM. This should make it easier for users to identify which GPIO
line corresponds to a respective GPIO pin on the device.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-02-01 16:05:28 +01:00
William Breathitt Gray 232a448706 gpio: gpio-mm: Remove unnecessary driver_data set
Setting driver_data was necessary to access private data in the
gpiomm_remove function. Now that the gpiomm_remove function is gone,
driver_data is no longer used. This patch removes the relevant code.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-02-01 15:59:20 +01:00
William Breathitt Gray 2141b0a1d7 gpio: gpio-mm: Utilize devm_ functions in driver probe callback
The devm_ resource manager functions allow memory to be automatically
released when a device is unbound. This patch takes advantage of the
resource manager functions and replaces the gpiochip_add_data call with
the devm_gpiochip_add_data call. In addition, the gpiomm_remove function
has been removed as no longer necessary due to the use of the relevant
devm_ resource manager functions.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 15:55:25 +01:00
William Breathitt Gray 65502a12ad gpio: gpio-mm: Add set_multiple callback function support
The Diamond Systems GPIO-MM series provides registers where 8 lines of
GPIO may be set at a time. This patch add support for the set_multiple
callback function, thus allowing multiple GPIO output lines to be set
more efficiently in groups.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 10:56:37 +01:00
William Breathitt Gray 6ea5dcdf79 gpio: Add GPIO support for the Diamond Systems GPIO-MM
The Diamond Systems GPIO-MM device features 48 lines of digital I/O via
the emulation of dual 82C55A PPI chips. This driver provides GPIO
support for these 48 channels of digital I/O. The base port addresses
for the devices may be configured via the base array module parameter.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-08-11 13:37:25 +02:00