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Martin Blumenstingl ed5e8f6891 arm64: dts: meson: g12a: x96-max: fix the Ethernet PHY reset line
The Odroid-N2 schematics show that the following pins are used for the
reset and interrupt lines:
- GPIOZ_14 is the PHY interrupt line
- GPIOZ_15 is the PHY reset line

The GPIOZ_14 and GPIOZ_15 pins are special. The datasheet describes that
they are "3.3V input tolerant open drain (OD) output pins". This means
the GPIO controller can drive the output LOW to reset the PHY. To
release the reset it can only switch the pin to input mode. The output
cannot be driven HIGH for these pins.
This requires configuring the reset line as GPIO_OPEN_DRAIN because
otherwise the PHY will be stuck in "reset" state (because driving the
pin HIGH seems to result in the same signal as driving it LOW).

The reset line works together with a pull-up resistor (R143 in the
Odroid-N2 schematics). The SoC can drive GPIOZ_14 LOW to assert the PHY
reset. However, since the SoC can't drive the pin HIGH (to release the
reset) we switch the mode to INPUT and let the pull-up resistor take
care of driving the reset line HIGH.

Switch to GPIOZ_15 for the PHY reset line instead of using GPIOZ_14
(which actually is the interrupt line).
Move from the "snps" specific resets to the MDIO framework's
reset-gpios because only the latter honors the GPIO flags.
Use the GPIO flags (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN) to match with
the pull-up resistor because this will:
- drive the output LOW to reset the PHY (= active low)
- switch the pin to INPUT mode so the pull-up will take the PHY out of
  reset

Fixes: 51d116557b2044 ("arm64: dts: meson-g12a-x96-max: Add Gigabit Ethernet Support")
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
2019-06-19 20:34:09 -07:00
arch arm64: dts: meson: g12a: x96-max: fix the Ethernet PHY reset line 2019-06-19 20:34:09 -07:00
block for-5.2/block-post-20190516 2019-05-16 19:08:15 -07:00
certs kexec, KEYS: Make use of platform keyring for signature verify 2019-02-04 17:34:07 -05:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-05-07 22:03:58 -07:00
Documentation ASoC: tohdmitx bindings 2019-06-14 15:55:25 -07:00
drivers clk: meson: meson8b: fix a typo in the VPU parent names array variable 2019-05-20 12:11:08 +02:00
fs This pull request contains the following fixes for UBIFS: 2019-05-19 15:22:03 -07:00
include ASoC: tohdmitx bindings 2019-06-14 15:55:25 -07:00
init initramfs: don't free a non-existent initrd 2019-05-18 15:52:26 -07:00
ipc ipc: do cyclic id allocation for the ipc object. 2019-05-14 19:52:52 -07:00
kernel Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
lib slab: remove /proc/slab_allocators 2019-05-16 15:51:55 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2019-05-19 12:15:32 -07:00
net treewide: prefix header search paths with $(srctree)/ 2019-05-18 11:49:57 +09:00
samples samples: guard sub-directories with CONFIG options 2019-05-18 11:29:01 +09:00
scripts kconfig: use 'else ifneq' for Makefile to improve readability 2019-05-19 09:34:35 +09:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-13 15:15:00 -07:00
sound sound fixes for 5.2-rc1 2019-05-17 13:57:54 -07:00
tools Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-19 11:20:22 -07:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt * ARM: support for SVE and Pointer Authentication in guests, PMU improvements 2019-05-17 10:33:30 -07:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
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.mailmap A reasonably busy cycle for docs, including: 2019-05-08 12:42:50 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Kbuild updates for v5.2 (2nd) 2019-05-19 11:53:58 -07:00
Makefile Linux 5.2-rc1 2019-05-19 15:47:09 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.