[PATCH 0/9] clk: sunxi-ng: Support A31/A31s CCU

Chen-Yu Tsai
2016-07-26T07:04:52Z

Hi everyone,

This series adds support for the A31/A31s CCU (clock control unit) with
the new sunxi-ng binding/driver. This is a near complete driver, with a
few features unimplemented or might need reworking:

- The HDMI mode of the PLL-MIPI clock is unsupported.

- The EMAC clock is unimplemented. In the past we modelled this as a
clock. Unforunately that doesn't work very well. While it is sort
of a clock control, with clock inverters and delay chains, it also
controls the interface mode of the EMAC. On later SoCs this register
is moved out of the CCU, into the system control register range.
Other platforms consider this a part of the ethernet controller glue
logic, and map and use it directly as part of the controller bindings.
I would like to do the same.

- The A31 has 2 SDRAM clocks and 2 MBUS clocks. As such we can't have
them all as the DRAM gate clocks' parent. Instead I'm using the MDFS
clock as their parent. It is unclear what MDFS actually is, but the
close proximity of the registers to the DRAM bits, and hints about
this tied to DRAM DVFS suggest this is a common memory bus. If we're
wrong we can always fix this as the relationship is part of the driver,
not the binding. Also, all 5 clocks are marked as critical.

Various changes were made to the common (to sunxi-ng) clock types to make
them compatible with the A31/A31s' CCU's design.

Also new is support for clk notifiers for mux clocks. This is needed for
the cpu clock, which should be muxed to the stable main oscillator when
the PLL-CPU clock rate is changed, to avoid any instabilities in the PLL
which result in the CPU crashing. This is similar to what the meson
platform does.

Regards
ChenYu

Chen-Yu Tsai (9):
clk: sunxi-ng: Fix inverted test condition in ccu_helper_wait_for_lock
clk: sunxi-ng: nk: Make ccu_nk_find_best static
clk: sunxi-ng: mux: Increase fixed pre-divider div size
clk: sunxi-ng: mux: Add support for mux tables
clk: sunxi-ng: mux: support fixed pre-dividers on multiple parents
clk: sunxi-ng: nkm: Add mux to support multiple parents
clk: sunxi-ng: mux: Add clk notifier functions
clk: sunxi-ng: Add A31/A31s clocks
ARM: dts: sun6i: switch A31/A31s to new CCU clock bindings

.../devicetree/bindings/clock/sunxi-ccu.txt | 3 +-
arch/arm/boot/dts/sun6i-a31.dtsi | 424 ++-----
drivers/clk/sunxi-ng/Kconfig | 10 +
drivers/clk/sunxi-ng/Makefile | 1 +
drivers/clk/sunxi-ng/ccu-sun6i-a31.c | 1230 ++++++++++++++++++++
drivers/clk/sunxi-ng/ccu-sun6i-a31.h | 72 ++
drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 9 +-
drivers/clk/sunxi-ng/ccu_common.c | 2 +-
drivers/clk/sunxi-ng/ccu_mux.c | 56 +-
drivers/clk/sunxi-ng/ccu_mux.h | 36 +-
drivers/clk/sunxi-ng/ccu_nk.c | 6 +-
drivers/clk/sunxi-ng/ccu_nkm.c | 40 +-
drivers/clk/sunxi-ng/ccu_nkm.h | 23 +
include/dt-bindings/clock/sun6i-a31-ccu.h | 187 +++
include/dt-bindings/reset/sun6i-a31-ccu.h | 106 ++
15 files changed, 1854 insertions(+), 351 deletions(-)
create mode 100644 drivers/clk/sunxi-ng/ccu-sun6i-a31.c
create mode 100644 drivers/clk/sunxi-ng/ccu-sun6i-a31.h
create mode 100644 include/dt-bindings/clock/sun6i-a31-ccu.h
create mode 100644 include/dt-bindings/reset/sun6i-a31-ccu.h

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2.8.1