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Marek Vasut 0e7d6f9401 gpio: of: Apply regulator-gpio quirk only to enable-gpios
Since commit d6cd33ad71 ("regulator: gpio: Convert to use descriptors")
the GPIO regulator had inverted the polarity of the control GPIO. This
problem manifested itself on systems with DT containing the following
description (snippet from salvator-common.dtsi):

	gpios = <&gpio5 1 GPIO_ACTIVE_HIGH>;
	gpios-states = <1>;
	states = <3300000 1
		  1800000 0>;

Prior to the aforementioned commit, the gpio-regulator code used
gpio_request_array() to claim the GPIO(s) specified in the "gpios"
DT node, while the commit changed that to devm_gpiod_get_index().

The legacy gpio_request_array() calls gpio_request_one() and then
gpiod_request(), which parses the DT flags of the "gpios" node and
populates the GPIO descriptor flags field accordingly.

The new devm_gpiod_get_index() calls gpiod_get_index(), then
of_find_gpio(), of_get_named_gpiod_flags() with flags != NULL,
and then of_gpio_flags_quirks(). Since commit a603a2b8d8
("gpio: of: Add special quirk to parse regulator flags"),
of_gpio_flags_quirks() contains a quirk for regulator-gpio
which was never triggered by the legacy gpio_request_array()
code path, but is triggered by devm_gpiod_get_index() code
path.

This quirk checks whether a GPIO is associated with a fixed
or gpio-regulator and if so, checks two additional conditions.
First, whether such GPIO is active-low, and if so, ignores the
active-low flag. Second, whether the regulator DT node does
have an "enable-active-high" property and if the property is
NOT present, sets the GPIO flags as active-low.

The second check triggers a problem, since it is applied to all
GPIOs associated with a gpio-regulator, rather than only on the
"enable" GPIOs, as the old code did. This changes the way the
gpio-regulator interprets the DT description of the control
GPIOs.

The old code using gpio_request_array() explicitly parsed the
"enable-active-high" DT property and only applied it to the
GPIOs described in the "enable-gpios" DT node, and only if
those were present.

This patch fixes the quirk code by only applying the quirk
to "enable-gpios", thus restoring the old behavior.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jan Kotas <jank@cadence.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-gpio@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-02-17 22:20:11 +01:00
Documentation gpio updates for v5.1 2019-02-17 21:59:33 +01:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch gpio updates for v5.1 2019-02-17 21:59:33 +01:00
block for-linus-20190209 2019-02-09 10:26:09 -08:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto crypto: sm3 - fix undefined shift by >= width of value 2019-01-10 21:37:32 +08:00
drivers gpio: of: Apply regulator-gpio quirk only to enable-gpios 2019-02-17 22:20:11 +01:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs for-linus-20190209 2019-02-09 10:26:09 -08:00
include gpio updates for v5.1 2019-02-17 21:59:33 +01:00
init psi: clarify the Kconfig text for the default-disable option 2019-02-01 15:46:24 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel gpio updates for v5.1 2019-02-17 21:59:33 +01:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 11:21:54 -08:00
mm mm: migrate: don't rely on __PageMovable() of newpage after unlocking it 2019-02-01 15:46:24 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 11:21:54 -08:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-01-30 15:24:45 +01:00
scripts Bug fixes for gcc-plugins 2019-01-21 13:07:03 +13:00
security apparmor: Fix aa_label_build() error handling for failed merges 2019-02-01 08:01:39 -08:00
sound sound fixes for 5.0-rc6 2019-02-07 08:33:56 +00:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-10 09:48:18 -08:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974) 2019-02-07 19:02:38 +01:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap A few early MIPS fixes for 4.21: 2019-01-05 12:48:25 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Add CREDITS entry for Shaohua Li 2019-01-04 14:27:09 -07:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2019-02-09 13:43:12 -08:00
Makefile Linux 5.0-rc6 2019-02-10 14:42:20 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.