Commit graph

48261 commits

Author SHA1 Message Date
David Wu
7cd4ebab2b clk: rockchip: Add rk3328 gamc clock support
The rk3328 soc has two gmac controllers, one is gmac2io,
the other is gmac2phy. We use the gmac2io rgmii interface
for 1000M phy here.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:37 +01:00
David Wu
dfb886d4f2 rockchip: pinctrl: Add rk3328 gmac pinctrl support
Need to set gmac m1 pins iomux, gmac m0 tx pins, select bit2
and bit10 at com iomux register. After that, set rgmii m1 tx
pins to 12ma drive-strength, and clean others to 2ma.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:37 +01:00
David Wu
301fff4e57 rockchip: pinctrl: rk3328: Move the iomux definitions into pinctrl-driver
Clean the iomux definitions at grf_rk3328.h, and move them into
pinctrl-driver for resolving the compiling error of redefinition.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:37 +01:00
David Wu
caf746172b net: gmac_rockchip: Add support for the RV1108 GMAC
The rv1108 GMAC only support rmii interface, so need to add the
set_rmii() ops. Use the phy current interface to set rmii or
rgmii ops. At the same time, need to set the mac clock rate of
rmii with 50M, the clock rate of rgmii with 125M.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:37 +01:00
David Wu
77c4261130 rockchip: pinctrl: rv1108: Move the iomux definitions into pinctrl-driver
If we include both the rk3288_grf.h and rv1108_grf.h, it will cause the
conflicts of redefinition. Clean the iomux definitions at grf_rv1108.h,
and move them into pinctrl-driver.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:36 +01:00
David Wu
0788a31e03 rockchip: grf_rv1108.h: Fix the grf offsets
The last 4 grf registers offset of rv1108 are wrong, fix them
for correct usage.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:36 +01:00
David Wu
c422c4fa31 rockchip: configs: Enable CONFIG_NET_RANDOM_ETHADDR for rk3288-evb
If the Ethernet address is not set, the network can't work,
enable the random address config for default use.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:36 +01:00
David Wu
dc5b201384 rockchip: dts: rk3399-evb: Change the tx/rx delay value for transmission quality
Give the mac controller the correct tx-delay and rx-delay value
for the rgmii mode transmission. If they are not matched, there
would be Ethernet packets lost, the net feature may not work.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-01-28 17:12:36 +01:00
Philipp Tomsich
d2f1f1abaf rockchip: clk: rk3399: accept all assigned-clocks from the 'cru'-node
The RK3399 CRU-node assigns rates to a number of clocks that are not
implemented in the RK3399 clock-driver (but which have been
sufficiently initialised from rkclk_init()): for these clocks, we
simply ignore the set_rate() operation and return 0 to signal success.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.
2018-01-28 17:12:36 +01:00
Philipp Tomsich
f4fcba5c5b clk: implement clk_set_defaults()
Linux uses the properties 'assigned-clocks', 'assigned-clock-parents'
and 'assigned-clock-rates' to configure the clock subsystem for use
with various peripheral nodes.

This implements clk_set_defaults() and hooks it up with the general
device probibin in drivers/core/device.c: when a new device is probed,
clk_set_defaults() will be called for it and will process the
properties mentioned above.

Note that this functionality is designed to fail gracefully (i.e. if a
clock-driver does not implement set_parent(), we simply accept this
and ignore the error) as not to break existing board-support.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.

Series-version: 2

Cover-letter:
clk: support assigned-clock, assigned-clock-parents, assigned-clock-rates

For various peripherals on Rockchip SoCs (e.g. for the Ethernet GMAC),
the parent-clock needs to be set via the DTS.  This adds the required
plumbing and implements the GMAC case for the RK3399.
END
2018-01-28 17:12:36 +01:00
Philipp Tomsich
a45f17e8b9 rockchip: clk: rk3399: implement set_parent() operation
This implements the (newly added) set_parent() operation for the
RK3399 with a focus on allowing the RGMII clock parent to be
configured via the assigned-clock-parents property of the GMAC node.

This implementation supports only the GMAC (in fact only the RGMII
clock parent) and allows to set this clock's parent either to the
internal SCLK_GMAC or to an external clock input (identifiable by it
providing a 'clock-output-name' of "gmac_clkin").

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.
2018-01-28 17:12:36 +01:00
Philipp Tomsich
95f9a7e595 clk: refactor clk_get_by_index() into clk_get_by_indexed_prop()
The logic in clk_get_by_index() may be useful for other properties
than 'clocks': e.g. 'assigned-clocks' and 'assigned-clock-parents'
follows the same model.

This commit refactors clk_get_by_index() by introducing an internal
function clk_get_by_indexed_prop() that allows to specify the name
of the property to process.  The original clk_get_by_index() call
is simply directed through this helper function with the property
name fixed to "clocks".

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.
2018-01-28 17:12:35 +01:00
Philipp Tomsich
f7d1046da1 clk: add clk_set_parent()
Clocks may support multiple parents: this change introduces an
optional operation on the clk-uclass to set a clock's parent.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: David Wu <david.wu@rock-chips.com>

Series-changes: 2
- Fixed David's email address.
2018-01-28 17:12:35 +01:00
Tom Rini
1a7f6d4597 Merge git://git.denx.de/u-boot-uniphier 2018-01-27 21:55:04 -05:00
Tom Rini
9c486e7cb0 Merge branch 'rmobile-mx' of git://git.denx.de/u-boot-sh 2018-01-27 18:25:00 -05:00
Masahiro Yamada
7d8cca7be6 ARM: uniphier: enable HS200 support for uniphier_v8_defconfig
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2018-01-28 06:32:50 +09:00
Tom Rini
f95a4b3a55 Merge git://git.denx.de/u-boot-usb 2018-01-27 14:48:52 -05:00
Tom Rini
d61639e39a Merge git://git.denx.de/u-boot-socfpga 2018-01-27 14:48:41 -05:00
Marek Vasut
789edf694c ARM: rmobile: Convert R8A7791 Porter board to DM and DT
Convert the R8A7791 Porter board to DM and DT. This implies mostly
enabling the necessary configuration options and plucking out the
ad-hoc configuration from the board file. Moreover, the pre-reloc
malloc size was increased to allow the clock driver to start up
early without running out of malloc space and the early stack was
moved further up in the DRAM to avoid rewriting U-Boot itself.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
bb834b6247 ARM: rmobile: Enable OF_CONTROL on RCar Gen2
Since the DTs are now in place, enable OF control so that they get
bundled into the U-Boot.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
30ceb10c4c ARM: dts: rmobile: Add SoC and board U-Boot DT extras
Add U-Boot DT extras for each SoC and board. This marks the required
nodes with u-boot,dm-pre-reloc to start clock and PRR early on while
avoiding modification of the DTs imported from Linux.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
a500e4e570 ARM: dts: rmobile: Add rudimentary R8A7790 Stout DT
The Stout board is not supported in Linux, so add a rudimentary DTS
for H2 Stout as a placeholder for when a proper DTS is available.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
---
NOTE: The Stout is already being shipped over, so proper DTS for both
      U-Boot and Linux will happen once it's delivered :-)
2018-01-27 20:38:54 +01:00
Marek Vasut
9a26fc5a73 ARM: dts: rmobile: Import R8A7794 DTS from Linux 4.15-rc8
Import the Renesas R8A7794 DTS and headers from upstream Linux kernel v4.15-rc8,
commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
92aa099592 ARM: dts: rmobile: Import R8A7793 DTS from Linux 4.15-rc8
Import the Renesas R8A7793 DTS and headers from upstream Linux kernel v4.15-rc8,
commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
a3fb9ff3b3 ARM: dts: rmobile: Import R8A7792 DTS from Linux 4.15-rc8
Import the Renesas R8A7792 DTS and headers from upstream Linux kernel v4.15-rc8,
commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
edd15fcffb ARM: dts: rmobile: Import R8A7791 DTS from Linux 4.15-rc8
Import the Renesas R8A7791 DTS and headers from upstream Linux kernel v4.15-rc8,
commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:54 +01:00
Marek Vasut
16b6e4aa37 ARM: dts: rmobile: Import R8A7790 DTS from Linux 4.15-rc8
Import the Renesas R8A7790 DTS and headers from upstream Linux kernel v4.15-rc8,
commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 .

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:53 +01:00
Marek Vasut
319202640a net: sh_eth: Add DM and DT support
Add DM capable code into the SH ethernet driver and support probing
both from DT and pdata. The legacy non-DM, non-DT support is retained
as there are still systems in the tree which are not DM or DT capable.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
a220784b14 net: sh_eth: Clump legacy functions together
Move the legacy functions around, so that they can be wrapped in a
massive ifdef CONFIG_DM_ETH once DM support is added. No functional
change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
013af64f8f net: sh_eth: Split sh_eth_init
Split sh_eth_init() function into smaller chunks, which can
be called from both DM and non-DM code while handling the
specifics of both configurations.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
68ac92e937 net: sh_eth: Separate out MAC address programming
Pull out the code for writing MAC address into the NIC into a
separate function, so it can be reused by both DM and non-DM
code. This is done in preparation for DM support, which handles
MAC address programming separately.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
52c15e220b net: sh_eth: Split sh_eth_recv
Split sh_eth_recv into two functions, one which checks whether
a packet was received and one which handles the received packet.
This is done in preparation for DM support, which handles these
two parts separately.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
dca221bd92 net: sh_eth: Pass sh_eth_dev around
Pass sh_eth_dev structure around instead of eth_device, since the
later is specific to the legacy networking support. This change is
done in preparation for the DM addition.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
effb79027e net: sh_eth: Unify CONFIG_R8A779[01234] as CONFIG_RCAR_GEN2
Use the common RCAR_GEN2 config option instead of enumerating
each SoC and having a lengthy ifdef clause. No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
e3105eacf5 net: ravb: staticize ravb_start
Cosmetic fix, make ravb_start() static.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
5f14f7d783 pci: rmobile: Add RCar Gen2 PCIe controller driver
Add driver for the Renesas RCar PCIe controller present on Gen2 SoCs.
The PCIe on Gen2 is used both to connect external PCIe peripherals as
well as access the on-SoC USB EHCI controller.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
2018-01-27 20:38:53 +01:00
Marek Vasut
8b05436ff5 gpio: rmobile: Add RCar Gen2 compatible string
Add DT compatible string for RCar Gen2.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2018-01-27 20:38:53 +01:00
Maxime Ripard
0163c9186b env: sunxi: Enable FAT-based environment support by default
Now that we have everything in place to implement the transition scheme,
let's enable it by default.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:23:32 -05:00
Maxime Ripard
b39117cad9 sunxi: Transition from the MMC to a FAT-based environment
The current environment has been hardcoded to an offset that starts to be
an issue given the current size of our main U-Boot binary.

By implementing a custom environment location routine, we can always favor
the FAT-based environment, and fallback to the MMC if we don't find
something in the FAT partition. We also implement the same order when
saving the environment, so that hopefully we can slowly migrate the users
over to FAT-based environment and away from the raw MMC one.

Eventually, and hopefully before we reach that limit again, we will have
most of our users using that setup, and we'll be able to retire the raw
environment, and gain more room for the U-Boot binary.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:23:22 -05:00
Maxime Ripard
40c08a68b9 env: Mark env_get_location as weak
Allow boards and architectures to override the default environment lookup
code by overriding env_get_location.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:23:22 -05:00
Maxime Ripard
fb69464eae env: Allow to build multiple environments in Kconfig
Now that we have everything in place in the code, let's allow to build
multiple environments backend through Kconfig.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:23:22 -05:00
Maxime Ripard
d282a1db6a env: mmc: depends on the MMC framework
The raw MMC environment directly calls into the MMC framework. Make sure
it's enabled before we can select it.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2018-01-27 09:21:57 -05:00
Maxime Ripard
1d4460871b env: Initialise all the environments
Since we want to have multiple environments, we will need to initialise
all the environments since we don't know at init time what drivers might
fail when calling load.

Let's init all of them, and only consider for further operations the ones
that have not reported any errors at init time.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:21:57 -05:00
Maxime Ripard
7d714a24d7 env: Support multiple environments
Now that we have everything in place to support multiple environment, let's
make sure the current code can use it.

The priority used between the various environment is the same one that was
used in the code previously.

At read / init times, the highest priority environment is going to be
detected, and we'll use the same one without lookup during writes. This
should implement the same behaviour than we currently have.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:21:57 -05:00
Maxime Ripard
58ae9990c0 env: common: Make the debug messages play a little nicer
Since we have global messages to indicate what's going on, the custom
messages in the environment drivers only make the output less readable.

Make the common code play a little nicer by removing all the extra output
in the standard case.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
29b8f21053 env: mmc: Make the debug messages play a little nicer
Since we have global messages to indicate what's going on, the custom
messages in the environment drivers only make the output less readable.

Make MMC play a little nicer by removing all the extra \n and formatting
that is redundant with the global output.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
d0816da54f env: fat: Make the debug messages play a little nicer
Since we have global messages to indicate what's going on, the custom
messages in the environment drivers only make the output less readable.

Make FAT play a little nicer by removing all the extra \n and formatting
that is redundant with the global output.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
3574ba019e env: Make it explicit where we're loading our environment from
Since we can have multiple environments now, it's better to provide a
decent indication on what environments were tried and which were the one to
fail and succeed.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
9efac3c805 env: Make the env save message a bit more explicit
Since we'll soon have support for multiple environments, the environment
saving message might end up being printed multiple times if the higher
priority environment cannot be used.

That might confuse the user, so let's make it explicit if the operation
failed or not.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
8a3a7e2270 env: Pass additional parameters to the env lookup function
In preparation for the multiple environment support, let's introduce two
new parameters to the environment driver lookup function: the priority and
operation.

The operation parameter is meant to identify, obviously, the operation you
might want to perform on the environment.

The priority is a number passed to identify the environment priority you
want to retrieve. The lowest priority parameter (0) will be the primary
source.

Combining the two parameters allow you to support multiple environments
through different priorities, and to change those priorities between read
and writes operations.

This is especially useful to implement migration mechanisms where you want
to always use the same environment first, be it to read or write, while the
common case is more likely to use the same environment it has read from to
write it to.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00