This is a simplified version of linux/arch/mips/bcm63xx/clk.c
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Align the at91 pmc's compatibles with kernel.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>
Add the compatible "atmel,at91rm9200-clk-master" to align with
the kernel.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Enhance the peripheral clock to support both at9sam9x5's and
at91rm9200's peripheral clock via the different compatibles.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Refactor SCU header to use consistent Mask & Shift values.
Now, consistently, to read value from SCU register, mask needs
to be applied before shift.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add support for clocks needed by MACs to ast2500 clock driver.
The clocks are D2-PLL, which is used by both MACs and PCLK_MAC1 and
PCLK_MAC2 for MAC1 and MAC2 respectively.
The rate of D2-PLL is hardcoded to 250MHz -- the value used in Aspeed
SDK. It is not entirely clear from the datasheet how this clock is used
by MACs, so not clear if the rate would ever need to be different. So,
for now, hardcoding it is probably safer.
The rate of PCLK_MAC{1,2} is chosen based on MAC speed selected through
hardware strapping.
So, the network driver would only need to enable these clocks, no need
to configure the rate.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add P-Bus Clock support to ast2500 clock driver.
This is the clock used by I2C devices.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Make functions for locking and unlocking SCU part of SCU API.
Many drivers need to modify settings in SCU and thus need to unlock it
first. This change makes it possible.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
With this gpio driver supporting DM, there is no need to enable clocks
for different gpios (for pin muxing) in the board specific code.
Need to increase the allocatable area required before relocation from 0x400 to
0xC00 becuase of 10 new gpio devices(& new gpio class) added in device tree.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
cc: Christophe KERELLO <christophe.kerello@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The clock driver for the RK3399 mistakenly used (24 * 2^20) where it
should have used (24 * 10^6) in a few calculations.
This commits fixes this.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
The Ethernet driver for the RK3288/3399 GMAC makes sure that the clock
is ungated through a call to clk_set_rate(...). Even though nothing
needs to be done on the RK3399 (the clock gates are open and the clock
is external), we need to implement enough support to at least return
success to enable driver probing.
X-AffectedPlatforms: RK3399-Q7
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
Due to differences in the code paths for SPL and non-SPL, some static
constant structures remain unused in each build variant. This raises
warnings with recent GCC versions (we currently use GCC-6.3).
The warnings addressed in this commit (by matching #if conditions for
the variable definition with their uses) are:
* for the SPL build:
drivers/clk/rockchip/clk_rk3399.c:53:29: warning: 'cpll_init_cfg' defined but not used [-Wunused-const-variable=]
static const struct pll_div cpll_init_cfg = PLL_DIVISORS(CPLL_HZ, 1, 2, 2);
^~~~~~~~~~~~~
drivers/clk/rockchip/clk_rk3399.c:52:29: warning: 'gpll_init_cfg' defined but not used [-Wunused-const-variable=]
static const struct pll_div gpll_init_cfg = PLL_DIVISORS(GPLL_HZ, 2, 2, 1);
^~~~~~~~~~~~~
* for the non-SPL build:
drivers/clk/rockchip/clk_rk3399.c:54:29: warning: 'ppll_init_cfg' defined but not used [-Wunused-const-variable=]
static const struct pll_div ppll_init_cfg = PLL_DIVISORS(PPLL_HZ, 2, 2, 1);
^~~~~~~~~~~~~
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
The armclk starts in slow mode (24MHz) on the rk3188, which makes the whole
startup take a lot of time. We therefore want to at least move to the safe
600MHz value we can use with default pmic settings.
This is also the freqency the proprietary sdram-init leaves the cpu at.
For boards that have pmic control later in u-boot, we also add the option
to set the maximum frequency of 1.6GHz, if they so desire.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
This includes support for rk3188 from Heiko Stübner and and rk3328 from
Kever Yang. Also included is SPL support for rk3399 and a fix for
rk3288 to get it booting again (spl_early_init()).
Before clock driver availability it was required to enable usart1 clock
for serial init but now with clock driver is taking care of usart1 clock.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
add basic clock driver support for stm32f7 to enable clocks required by
the peripherals.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add a driver for setting up and modifying the various PLLs and peripheral
clocks on the RK3188.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
The gpll and cpll init values are only used in rk_clk_init in the SPL
and therefore produce compile time warnings in regular uboot builds.
Fix that with an #ifdef.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
Added rockchip tag:
Signed-off-by: Simon Glass <sjg@chromium.org>
Right now the u-boot,dm-pre-reloc flag will make each marked node
always appear in both spl and tpl. But systems needing an additional
tpl might have special constraints for each, like the spl needing to
be very tiny.
So introduce two additional flags to mark nodes for only spl or tpl
environments and introduce a function dm_fdt_pre_reloc to automate
the necessary checks in code instances checking for pre-relocation
flags.
The behaviour of the original flag stays untouched and still marks
a node for both spl and tpl.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
Add support for the optional ethernet emio clock source to the zynq
clock framework driver.
Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Add a clock framework driver for the zynq platform. The driver is based
on the platform zynq clock driver but reworked to use static functions
instead of run-time generated objects even for unused clocks.
Additionally the CONFIG_ZYNQ_PS_CLK_FREQ is replaced by the
ps-clk-frequency from the device tree.
Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Fix H-PLL and M-PLL rate calculation in ast2500 clock driver.
Without this fix, valid setting can lead to division by zero
when requesting the rate of H-PLL or M-PLL clocks.
Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
At present devices use a simple integer offset to record the device tree
node associated with the device. In preparation for supporting a live
device tree, which uses a node pointer instead, refactor existing code to
access this field through an inline function.
Signed-off-by: Simon Glass <sjg@chromium.org>
Clock Driver
This driver is ast2500-specific and is not compatible with earlier
versions of this chip. The differences are not that big, but they are
in somewhat random places, so making it compatible with ast2400 is not
worth the effort at the moment.
SDRAM MC driver
The driver is very ast2500-specific and is completely incompatible
with previous versions of the chip.
The memory controller is very poorly documented by Aspeed in the
datasheet, with any mention of the whole range of registers missing. The
initialization procedure has been basically taken from Aspeed SDK, where
it is implemented in assembly. Here it is rewritten in C, with very limited
understanding of what exactly it is doing.
Reviewed-by: Simon Glass <sjg@chromium.org>
Add basic clock driver support for zynqmp which
sets the required clock for GEM controller
Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add basic support for setting the ARM clock, since this allows us to run
at maximum speed in U-Boot. Currently only a single speed is supported
(1.8GHz).
Signed-off-by: Simon Glass <sjg@chromium.org>
This function is called from outside the driver. It should be placed into
common SoC code. Move it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
This function is called from outside the driver. It should be placed into
common SoC code. Move it.
Also rename the driver symbol to be more consistent with the other rockchip
clock drivers.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
This function is called from outside the driver. It should be placed into
common SoC code. Move it.
Also rename the driver symbol to be more consistent with the other rockchip
clock drivers.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
For the peripheral clock, provide the clock ops for the clock
provider, such as spi0_clk. The .of_xlate is to get the clk->id,
the .enable is to enable the spi0 peripheral clock, the .get_rate
is to get the clock frequency.
The driver for periph32ck node is responsible for recursively
binding its children as clk devices, not provide the clock ops.
So do the generated clock and system clock.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
In order to make clk->dev available in ops->of_xlate() to get the
clock ID from the 'reg' property of the clock node, assign the
clk->dev before calling ops->of_xlate().
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
The at91-pmc and at91-sckc aren't the clock providers, change their
class ID from UCLASS_CLK to UCLASS_SIMPLE_BUS, they also don't
need to bind the child nodes explicitly, the .post_bind callback
of simple_bus uclass will do it for them.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The initial design of the UniPhier clk driver for U-Boot was not
very nice. Here is a re-work to sync it with Linux's clk and reset
drivers, maximizing the code reuse from Linux's clk data.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
These have now landed upstream. The naming is different and in one case the
function signature has changed. Update the code to match.
This applies the following upstream commits by
Thierry Reding <treding@nvidia.com> :
604e61e fdt: Add functions to retrieve strings
8702bd1 fdt: Add a function to get the index of a string
2218387 fdt: Add a function to count strings
Signed-off-by: Simon Glass <sjg@chromium.org>
Implement a clock uclass driver for the Tegra CAR. This allows clients to
use standard clock APIs on Tegra. This device is intended to be
instantiated by the core Tegra CAR driver, rather than being instantiated
directly from DT. The implementation uses the existing custom Tegra-
specific clock APIs to avoid coupling the series with significant
refactoring of the existing Tegra clock/clock code. The driver currently
only supports peripheral clocks, and avoids support for other clocks such
as PLLs and external clocks. This should be sufficient to convert over all
Tegra peripheral drivers, and avoids a complex implementation which calls
different Tegra-specific clock APIs based on the type of clock being
manipulated.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
To sync the DT binding with Linux, the register base must be taken
from the parent syscon node.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Move U_BOOT_DRIVER() entry from the data file (clk-uniphier-mio.c)
to the core support file (clk-uniphier-core.c) because I do not want
to repeat the driver boilerplate when I add more clock data.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
pmucru is a module like cru which is a clock controller manage some PLL
and module clocks.
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Add a simple driver for the clocks provided by the MIPS Boston
development board. The system provides information about 2 clocks whose
rates are fixed by the bitfile flashed in the boards FPGA, and this
driver simply reads the rates of these 2 clocks.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The patch is referred to at91 clock driver of Linux, to make
the clock node descriptions in DT aligned with the Linux's.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
In Tegra186, on-SoC clocks are manipulated using IPC requests to the BPMP
(Boot and Power Management Processor). This change implements a driver
that does that. A tegra/ sub-directory is created to follow the existing
pattern. It is unconditionally selected by CONFIG_TEGRA186 since virtually
any Tegra186 build of U-Boot will need the feature.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
The already available ilog2 function does exactly the same in the common
case than the log2 function the current clock-driver reimplement.
So, simply move to that one.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
MMC core will use 400KHz for card initialize first and then switch to
higher frequency like 50MHz, we need to support both 400KHz and about
50MHz for dwmmc controller.
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
With the number of Rockchip clock drivers increasing, don't clutter up
the core drivers/clk directory with them and instead move them out of
the way into a separate subdirectory.
Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
Updated for rk3399:
Signed-off-by: Simon Glass <sjg@chromium.org>
The current code picks the first available clock. In U-Boot proper this is
the oscillator device, not the SoC clock device. As a result the HDMI display
does not work.
Fix this by calling rockchip_get_clk() instead.
Fixes: 135aa950 (clk: convert API to match reset/mailbox style)
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
According to the TRM the minimum FREF frequency is 269kHz not MHz.
Adapt the constant accordingly.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
The function is very specific to the rk3288 in its arguments
referencing the rk3288 cru and grf and every other rockchip soc
has differing cru and grf registers. So make that function naming
explicit.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
This does not have much impact on behavior, but makes code look more
more like Linux. The use of devm_ioremap() often helps to delete
.remove callbacks entirely.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Simple version of clk_get_by_index() added by:
"dm: clk: Add a simple version of clk_get_by_index()"
(sha1: a4b10c088c)
is only working for #clock-cells=<1> but not for
any other values. Fixed clocks is using #clock-cells=<0>
which requires full implementation.
Remove simplified versions of clk_get_by_index() and use full version.
Also remove empty clk_get_by_name() which is failing when it is called
which is useless.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Add support for of-platdata with rk3288. This requires decoding the
of-platdata struct and setting up the devices from that. Also the driver
needs to be renamed to match the string that of-platdata will search for.
Signed-off-by: Simon Glass <sjg@chromium.org>
It is more correct to avoid touching the device tree in the probe() method.
Update the driver to work this way. Also add an error check on grf since if
that fails then we should not use it.
Signed-off-by: Simon Glass <sjg@chromium.org>
clk->id is unsigned, so it can't be < 0. Remove the check for that.
FWIW, this issue was introduced when the clock API converted e.g.
clk_get_rate()'s clock ID parameter from an int to an unsigned long
(with a struct clk), without removing this check.
Fixes: 135aa95002 ("clk: convert API to match reset/mailbox style")
Reported-by: Coverity Scan
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
The following changes are made to the clock API:
* The concept of "clocks" and "peripheral clocks" are unified; each clock
provider now implements a single set of clocks. This provides a simpler
conceptual interface to clients, and better aligns with device tree
clock bindings.
* Clocks are now identified with a single "struct clk", rather than
requiring clients to store the clock provider device and clock identity
values separately. For simple clock consumers, this isolates clients
from internal details of the clock API.
* clk.h is split so it only contains the client/consumer API, whereas
clk-uclass.h contains the provider API. This aligns with the recently
added reset and mailbox APIs.
* clk_ops .of_xlate(), .request(), and .free() are added so providers
can customize these operations if needed. This also aligns with the
recently added reset and mailbox APIs.
* clk_disable() is added.
* All users of the current clock APIs are updated.
* Sandbox clock tests are updated to exercise clock lookup via DT, and
clock enable/disable.
* rkclk_get_clk() is removed and replaced with standard APIs.
Buildman shows no clock-related errors for any board for which buildman
can download a toolchain.
test/py passes for sandbox (which invokes the dm clk test amongst
others).
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
For odroid-c2 (arch-meson) for now disable designware eth as meson
now needs to do some harder GPIO work.
Signed-off-by: Tom Rini <trini@konsulko.com>
Conflicts:
lib/efi_loader/efi_disk.c
Modified:
configs/odroid-c2_defconfig
Setup the clocks for the gmac ethernet interface. This assumes the mac
clock is fed by an external clock which is common on RK3288 based
devices.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Simon Glass <sjg@chromium.org>
The current reset API implements a method to reset the entire system.
In the near future, I'd like to introduce code that implements the device
tree reset bindings; i.e. the equivalent of the Linux kernel's reset API.
This controls resets to individual HW blocks or external chips with reset
signals. It doesn't make sense to merge the two APIs into one since they
have different semantic purposes. Resolve the naming conflict by renaming
the existing reset API to sysreset instead, so the new reset API can be
called just reset.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Add a clock driver for Exynos7420 SoC. There are about 25 clock controller
blocks in Exynos7420 out of which support for topc, top0 and peric1 blocks
are added in this initial version of the driver.
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Currently, fdtdec_get_addr_size() does not support the address
translation, so it cannot handle device trees with non-straight
"ranges" properties. (This would be a problem with DTS for UniPhier
ARMv8 SoCs.)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This is the initial commit for the UniPhier clock drivers.
Currently, only the Media I/O clock is supported.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
PIC32 clock module consists of multiple oscillators, PLLs, mutiplexers
and dividers capable of supplying clock to various controllers
on or off-chip.
Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Add a feature which speeds up the CPU to full speed in SPL to minimise
boot time. This is only supported for certain boards (at present only
jerry).
Signed-off-by: Simon Glass <sjg@chromium.org>
The displays need to use NPLL and also select some new peripheral clocks.
Add support for these to the clock driver.
Signed-off-by: Simon Glass <sjg@chromium.org>
The current method assumes that clocks are numbered from 0 and we can
determine a clock by its number. It is safer to use an ID in the clock's
platform data to avoid the situation where another clock is bound before
the one we expect.
Move the existing code into rk3036 since it still works there. Add a new
implementation for rk3288.
Signed-off-by: Simon Glass <sjg@chromium.org>
This function adds quite a bit of code to SPL and we probably don't need
all the features in SPL. Add a simple version (for SPL only) to save space.
Signed-off-by: Simon Glass <sjg@chromium.org>
The current approach of using uclass_get_device() is error-prone. Another
clock (for example a fixed-clock) may cause it to break. Add a function that
does a proper search.
Signed-off-by: Simon Glass <sjg@chromium.org>
At present we use the same peripheral ID for clocks and pinctrl. While this
works it is probably better to use the device tree clock binding ID for
clocks. We can use the clk_get_by_index() function to find this.
Update the clock drivers and the code that uses them.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add a method which can locate a clock for a device, given its index. This
uses the normal device tree bindings to return the clock device and the
first argument which is normally used as a peripheral ID in U-Boot.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit intends to implement "fixed-clock" as in Linux.
(drivers/clk/clk-fixed-rate.c in Linux)
If you need a very simple clock to just provide fixed clock rate
like a crystal oscillator, you do not have to write a new driver.
This driver can support it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
The most basic thing for clock is to enable it, but it is missing
in this uclass.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
Add a driver for setting up and modifying the various PLLs, peripheral
clocks and mmc clocks on RK3036
Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Clocks are an important feature of platforms and have become increasing
complex with time. Most modern SoCs have multiple PLLs and dozens of clock
dividers which distribute clocks to on-chip peripherals.
Some SoC implementations have a clock API which is private to that SoC family,
e.g. Tegra and Exynos. This is useful but it would be better to have a
common API that can be understood and used throughout U-Boot.
Add a simple clock API as a starting point. It supports querying and setting
the rate of a clock. Each clock is a device. To reduce memory and processing
overhead the concept of peripheral clocks is provided. These do not need to
be explicit devices - it is possible to write a driver that can adjust the
I2C clock (for example) without an explicit I2C clock device. This can
dramatically reduce the number of devices (and associated overhead) in a
complex SoC.
Clocks are referenced by a number, and it is expected that SoCs will define
that numbering themselves via an enum.
Signed-off-by: Simon Glass <sjg@chromium.org>
