On Fri, Nov 03, 2017 at 03:25:06PM +0800, Kaihua Zhong wrote:

Hi3660 has four stub clocks, which are big and LITTLE cluster clocks,
GPU clock and DDR clock.  These clocks ask MCU for frequency scaling
by sending message through mailbox.

This commit adds support for stub clocks, it requests the dedicated
mailbox channel at initialization; then later uses this channel to send
message to MCU to execute frequency scaling. The four stub clocks share
the same mailbox channel, but every stub clock has its own command id so
MCU can distinguish the requirement coming for which clock.

A shared memory is used to present effective frequency value, so the
clock driver uses I/O mapping for the memory and reads back rate value.

Reviewed-by: Leo Yan <redacted>
Signed-off-by: Kai Zhao <redacted>
Signed-off-by: Kevin Wang <redacted>
Signed-off-by: Ruyi Wang <redacted>
Signed-off-by: Kaihua Zhong <redacted>
---
 drivers/clk/hisilicon/Kconfig            |   6 +
 drivers/clk/hisilicon/Makefile           |   1 +
 drivers/clk/hisilicon/clk-hi3660-stub.c  | 195 +++++++++++++++++++++++++++++++

 include/dt-bindings/clock/hi3660-clock.h |   7 ++

This belongs in the binding doc patch. But no need to respin just for 
that. 

 4 files changed, 209 insertions(+)
 create mode 100644 drivers/clk/hisilicon/clk-hi3660-stub.c