linux/drivers/clk/baikal-t1/Kconfig
Serge Semin 70fa895488 clk: baikal-t1: Move reset-controls code into a dedicated module
Before adding the directly controlled resets support it's reasonable to
move the existing resets control functionality into a dedicated object for
the sake of the CCU dividers clock driver simplification. After the new
functionality was added clk-ccu-div.c would have got to a mixture of the
weakly dependent clocks and resets methods. Splitting the methods up into
the two objects will make the code easier to read and maintain. It shall
also improve the code scalability (though hopefully we won't need this
part that much in the future).

The reset control functionality is now implemented in the framework of a
single unit since splitting it up doesn't make much sense due to
relatively simple reset operations. The ccu-rst.c has been designed to be
looking like ccu-div.c or ccu-pll.c with two globally available methods
for the sake of the code unification and better code readability.

This commit doesn't provide any change in the CCU reset implementation
semantics. As before the driver will support the trigger-like CCU resets
only, which are responsible for the AXI-bus, APB-bus and SATA-ref blocks
reset. The assert/de-assert-capable reset controls support will be added
in the next commit.

Note the CCU Clock dividers and resets functionality split up was possible
due to not having any side-effects (at least we didn't found ones) of the
regmap-based concurrent access of the common CCU dividers/reset CSRs.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20220929225402.9696-6-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-09-30 14:19:33 -07:00

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# SPDX-License-Identifier: GPL-2.0-only
config CLK_BAIKAL_T1
bool "Baikal-T1 Clocks Control Unit interface"
depends on (MIPS_BAIKAL_T1 && OF) || COMPILE_TEST
default MIPS_BAIKAL_T1
help
Clocks Control Unit is the core of Baikal-T1 SoC System Controller
responsible for the chip subsystems clocking and resetting. It
consists of multiple global clock domains, which can be reset by
means of the CCU control registers. These domains and devices placed
in them are fed with clocks generated by a hierarchy of PLLs,
configurable and fixed clock dividers. Enable this option to be able
to select Baikal-T1 CCU PLLs and Dividers drivers.
if CLK_BAIKAL_T1
config CLK_BT1_CCU_PLL
bool "Baikal-T1 CCU PLLs support"
select MFD_SYSCON
default MIPS_BAIKAL_T1
help
Enable this to support the PLLs embedded into the Baikal-T1 SoC
System Controller. These are five PLLs placed at the root of the
clocks hierarchy, right after an external reference oscillator
(normally of 25MHz). They are used to generate high frequency
signals, which are either directly wired to the consumers (like
CPUs, DDR, etc.) or passed over the clock dividers to be only
then used as an individual reference clock of a target device.
config CLK_BT1_CCU_DIV
bool "Baikal-T1 CCU Dividers support"
select MFD_SYSCON
default MIPS_BAIKAL_T1
help
Enable this to support the CCU dividers used to distribute clocks
between AXI-bus and system devices coming from CCU PLLs of Baikal-T1
SoC. CCU dividers can be either configurable or with fixed divider,
either gateable or ungateable. Some of the CCU dividers can be as well
used to reset the domains they're supplying clock to.
config CLK_BT1_CCU_RST
bool "Baikal-T1 CCU Resets support"
select RESET_CONTROLLER
select MFD_SYSCON
default MIPS_BAIKAL_T1
help
Enable this to support the CCU reset blocks responsible for the
AXI-bus and some subsystems reset. These are mainly the
self-deasserted reset controls but there are several lines which
can be directly asserted/de-asserted (PCIe and DDR sub-domains).
endif