Thread (7 messages) 7 messages, 2 authors, 2018-11-22

[PATCH 0/3] Meson8b: add the CPU clock post-dividers

From: jbrunet@baylibre.com (Jerome Brunet)
Date: 2018-11-22 09:05:56
Also in: linux-amlogic, linux-clk, lkml

On Fri, 2018-11-16 at 21:53 +0100, Martin Blumenstingl wrote:
This is the successor to my previous series "meson8b: add the CPU_DIV16
clock for the ARM TWD" from [0]. I decided to not send this as v2 of
the original series because the PERIPH clock is not the CPU_DIV16 clock.
It's not clear whether a CPU_DIV16 clock exists.

With this series we get all the CPU_CLK post-dividers as listed in the
public S805 datasheet [1] on pages 31 and 32:
- ABP
- PERIPH (used as input for the ARM global timer and ARM TWD timer)
- AXI
- L2 DRAM

Each of these clocks has a register called "..._CLK_DIS" which is
documented as a "just in case" bit:
"Set to 1 to manually disable the [...] clock when changing the mux
selection. Typically this bit is set to 0 since the clock muxes can
switch without glitches."
Since we're not supposed to touch that register we're setting
CLK_IS_CRITICAL for these clocks in the driver.
If we are not supposed to touch the register, I'd prefer if you used RO ops
instead of using CLK_IS_CRITICAL.
The result of this is that we can use the PERIPH clock which clocks
the ARM TWD timer. I will send a separate series to add the TWD timer.


[0] http://lists.infradead.org/pipermail/linux-amlogic/2018-July/007890.html
[1] 
https://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf

Martin Blumenstingl (3):
  dt-bindings: clock: meson8b: export the CPU post dividers
  clk: meson: meson8b: rename cpu_div2/cpu_div3 to
    cpu_in_div2/cpu_in_div3
  clk: meson: meson8b: add the CPU clock post divider clocks

 drivers/clk/meson/meson8b.c              | 268 ++++++++++++++++++++++-
 drivers/clk/meson/meson8b.h              |  17 +-
 include/dt-bindings/clock/meson8b-clkc.h |   4 +
 3 files changed, 276 insertions(+), 13 deletions(-)
With CLK_IS_CRITICAL removed, looks good to me:

Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help