Hi all,
Currently the R-Car Clock Pulse Generator (CPG) drivers obtains the
state of the mode pins either by a call from the board code, or directly
by using a hardcoded register access. This is a bit messy, and creates a
dependency between driver and platform code.
This RFC patch series converts the various Renesas R-Car clock drivers
and support code from reading the mode pin states using a hardcoded
register access to using a new R-Car RST driver.
This series consists of 5 parts:
A. Patches 1 and 2 add DT bindings and driver code for the R-Car RST
driver,
B. Patches 3-10 add device nodes for the RST modules to the R-Car DTS
files,
C. Patches 11-16 convert the clock drivers to call into the new R-Car
RST driver,
D. Patches 17-19 remove passing mode pin state to the clock drivers
from the board code,
E. Patches 20-22 remove dead code from the clock drivers.
I've kept all parts together as this is an RFC, and to avoid losing the
bigger picture. I will split it in series per maintainer, when we have
decided how to handle the dependencies (see below).
After this, there are still a few users of rcar_gen2_read_mode_pins()
left in board code, which should be converted in one way or another.
However, all R-Car clock drivers will rely on the presence in DT of a
device node for the RST module. Backwards compatibility with old DTBs
is retained only for R-Car Gen2, which has fallback code calling into
rcar_gen2_read_mode_pins().
As is usually the case with moving functionality from board code to DT,
there are lots of hard dependencies:
- The DT updates in Part B can be merged as soon as the DT bindings in
Part A have been approved,
- The clock driver updates in Part C depend functionally on the driver
code in Part A,
- The board code cleanups in Part D depend on the clock driver updates
in Part C,
- The block driver cleanups in part E depend on the board code
cleanups in part D.
This series has evolved over time, cfr.
- "[PATCH/RFC 00/11] ARM: shmobile: Let CPG use syscon for MD pin
values" (http://www.spinics.net/lists/linux-clk/msg01478.html),
- "[PATCH 00/10] arm64: renesas: Obtain MD pin values using
syscon/regmap".
(http://www.spinics.net/lists/linux-sh/msg44757.html)
Changes compared to v2:
- Use "renesas,<soctype>-rst" instead of "renesas,rst-<soctype>",
- Drop "syscon" compatible value and "renesas,modemr" property, use a
real driver instead,
- Add support for R-Car M1A, H1, and M3-W.
Changes compared to v1:
- Add support for R-Car H3.
An alternative and broader solution was proposed by Simon Horman as
"[PATCH/RFC 0/6] boot-mode-reg: Add core"
(http://www.spinics.net/lists/linux-sh/msg45969.html).
This patch series is against renesas-drivers.
It has been tested on r8a7778/bockw, r8a7779/marzen, r8a7791/koelsch,
and r8a7795/salvator-x.
Thanks for your comments!
Geert Uytterhoeven (22):
reset: Add renesas,rst DT bindings
soc: renesas: Add R-Car RST driver
ARM: dts: r8a7778: Add device node for RESET/WDT module
ARM: dts: r8a7779: Add device node for RESET/WDT module
ARM: dts: r8a7790: Add device node for RST module
ARM: dts: r8a7791: Add device node for RST module
ARM: dts: r8a7793: Add device node for RST module
ARM: dts: r8a7794: Add device node for RST module
arm64: renesas: r8a7795 dtsi: Add device node for RST module
arm64: renesas: r8a7796 dtsi: Add device node for RST module
clk: renesas: r8a7778: Obtain mode pin values using R-Car RST driver
clk: renesas: r8a7779: Obtain mode pin values from R-Car RST driver
clk: renesas: rcar-gen2: Obtain mode pin values using RST driver
clk: renesas: r8a7795: Obtain mode pin values from R-Car RST driver
clk: renesas: r8a7796: Obtain mode pin values from R-Car RST driver
clk: renesas: rcar-gen3-cpg: Remove obsolete
rcar_gen3_read_mode_pins()
ARM: shmobile: r8a7778: Stop passing mode pins state to clock driver
ARM: shmobile: r8a7779: Stop passing mode pins state to clock driver
ARM: shmobile: rcar-gen2: Stop passing mode pins state to clock driver
clk: renesas: r8a7778: Remove obsolete r8a7778_clocks_init()
clk: renesas: r8a7779: Remove obsolete r8a7779_clocks_init()
clk: renesas: rcar-gen2: Remove obsolete rcar_gen2_clocks_init()
.../devicetree/bindings/reset/renesas,rst.txt | 35 ++++++++
arch/arm/boot/dts/r8a7778.dtsi | 5 ++
arch/arm/boot/dts/r8a7779.dtsi | 5 ++
arch/arm/boot/dts/r8a7790.dtsi | 5 ++
arch/arm/boot/dts/r8a7791.dtsi | 5 ++
arch/arm/boot/dts/r8a7793.dtsi | 5 ++
arch/arm/boot/dts/r8a7794.dtsi | 5 ++
arch/arm/mach-shmobile/setup-r8a7778.c | 15 ----
arch/arm/mach-shmobile/setup-r8a7779.c | 27 -------
arch/arm/mach-shmobile/setup-rcar-gen2.c | 6 +-
arch/arm64/boot/dts/renesas/r8a7795.dtsi | 5 ++
arch/arm64/boot/dts/renesas/r8a7796.dtsi | 5 ++
drivers/clk/renesas/clk-r8a7778.c | 26 +++---
drivers/clk/renesas/clk-r8a7779.c | 18 ++---
drivers/clk/renesas/clk-rcar-gen2.c | 17 ++--
drivers/clk/renesas/r8a7795-cpg-mssr.c | 8 +-
drivers/clk/renesas/r8a7796-cpg-mssr.c | 8 +-
drivers/clk/renesas/rcar-gen3-cpg.c | 17 ----
drivers/clk/renesas/rcar-gen3-cpg.h | 1 -
drivers/soc/renesas/Makefile | 5 ++
drivers/soc/renesas/rcar-rst.c | 94 ++++++++++++++++++++++
include/linux/clk/renesas.h | 4 -
include/linux/soc/renesas/rcar-rst.h | 6 ++
23 files changed, 227 insertions(+), 100 deletions(-)
create mode 100644 Documentation/devicetree/bindings/reset/renesas,rst.txt
create mode 100644 drivers/soc/renesas/rcar-rst.c
create mode 100644 include/linux/soc/renesas/rcar-rst.h
--
1.9.1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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