[PATCH v3 00/27] serial: sh-sci: External Clock Support

[Geert Uytterhoeven <geert+renesas@glider.be>]

	Hi Greg, Simon, Magnus, Sato-san,

This patch series contains several patches for the Renesas SCI serial
driver:
  - Clean up the naming of clocks in the driver and its DT bindings,
  - Add support for the optional external clock on (H)SCI(F) and some
    SCIFA, where this pin can serve as a clock input,
  - Add support for the optional clock sources for the Baud Rate
    Generator for External Clock (BRG), as found on some SCIF variants
    and on HSCIF.
Using external clocks increases the range and accuracy of supported baud
rates.

This series is an updated version of the core (driver) changes of two
series I sent before:
  - [PATCH v2 00/16] serial: sh-sci: Clock Cleanups
    (http://www.spinics.net/lists/linux-serial/msg19762.html)
  - [PATCH 00/25] serial: sh-sci: Add external clock and BRG Support
    (https://lkml.org/lkml/2015/11/19/550)
To reduce (cross) dependencies, I split off the integration (DTS)
patches into separate series:
  - "[PATCH 0/7] ARM: shmobile: dtsi: Add SCIF fallback compatibility
     strings",
  - "[PATCH v3 00/12] ARM: shmobile: dtsi: Rename the serial port
     clock to fck",
  - "[PATCH v2 0/7] ARM: shmobile: dtsi: Add BRG support for (H)SCIF",
  - "[PATCH v2 0/9] ARM: shmobile: dts: Enable SCIF_CLK frequency and
    pins".
As the SH architecture is orphaned, and the risk of conflicts is small,
I have bundled all SH-specific changes with the core changes.  This
reduces dependencies, too.

Changes compared to previous submission (more detailed information in
the individual patches):
  - Add fallback compatibility strings for R-Car Gen1, Gen2, Gen3, which
    allows the driver to match on (less) family-specific instead of
    (more) SoC-specific compatible values,
  - Rename "int_clk" to "brg_int", "SCI_INT_CLK" to "SCI_BRG_INT",
  - Terminate loops over sampling rates on perfect matches,
  - Many comments and clarifications in patch descriptions,
  - Add Acked-by, Reviewed-by.


This series consists of several parts:
  - The first four patches update DT binding documentation.
    The first patch also updates the driver, and is a hard dependency
    for the integration (DTS) patches, and for the SH patches.

    [01/27] serial: sh-sci: Drop the interface clock
    [02/27] serial: sh-sci: Add fallback compatibility strings (NEW)
    [03/27] serial: sh-sci: Update DT binding documentation for external
			    clock input
    [04/27] serial: sh-sci: Update DT binding documentation for BRG
			    support

  - Patches 5-23 update the driver only, and add external clock and BRG
    support.

    [05/27] serial: sh-sci: Drop useless check for zero
    [06/27] serial: sh-sci: Grammar s/Get ... for/Get ... from/
    [07/27] serial: sh-sci: Use existing local variable in
			    sci_parse_dt() (NEW)
    [08/27] serial: sh-sci: Drop unused frame_len parameter for
			    sci_baud_calc_hscif()
    [09/27] serial: sh-sci: Don't overwrite clock selection in
			    serial_console_write()
    [10/27] serial: sh-sci: Convert from clk_get() to devm_clk_get()
    [11/27] serial: sh-sci: Make unsigned values in
			    sci_baud_calc_hscif() unsigned
    [12/27] serial: sh-sci: Avoid overflow in sci_baud_calc_hscif()
    [13/27] serial: sh-sci: Improve bit rate error calculation for
			    HSCIF
    [14/27] serial: sh-sci: Avoid calculating the receive margin for
			    HSCIF
    [15/27] serial: sh-sci: Merge sci_scbrr_calc() and
			    sci_baud_calc_hscif()
    [16/27] serial: sh-sci: Take into account sampling rate for max baud
			    rate
    [17/27] serial: sh-sci: Add BRG register definitions
    [18/27] serial: sh-sci: Replace struct sci_port_info by type/regtype
			    encoding
    [19/27] serial: sh-sci: Correct SCIF type on RZ/A1H
    [20/27] serial: sh-sci: Correct SCIF type on R-Car for BRG
    [21/27] serial: sh-sci: Prepare for multiple sampling clock sources
    [22/27] serial: sh-sci: Add support for optional external (H)SCK
			    input
    [23/27] serial: sh-sci: Add support for optional BRG on H)SCIF

  - Patches 24-26 update the SH architecture.
    Patches 24 and 25 have a hard dependency on patch 1.
    Patch 26 has a hard dependency on patch 17.

    [24/27] sh: Rename sci_ick and sci_fck clock to fck
    [25/27] sh: Remove sci_ick clock alias
    [26/27] sh: sh7734: Correct SCIF type for BRG

  - Patch 27 has a hard dependency on patch 24.

    [27/27] serial: sh-sci: Drop the sci_fck clock fallback

Testing:
  - The Baud Rate Generator for External Clock (BRG) was tested on
      - R-Car Gen1 (r8a7778/bockw, r8a7779/marzen, on SCIF),
      - R-Car Gen2 (r8a7791/koelsch, on SCIF and HSCIF),
      - R-Car Gen3 (r8a7795/salvator-x, on SCIF and HSCIF),
  - The external clock input on (H)SCK was tested on
      - R-Car Gen3 (r8a7795/salvator-x, on SCIF and HSCIF),
  - Regression testing was done on Renesas ARM platforms that use SCIFA
    as the console (r8a73a4/ape6evm, r8a7740/armadillo, and
    sh73a0/kzm9g),
  - You can find more testing-related information in the final
    integration series.

Merge strategy:
  - This series applies to v4.4-rc1,
  - It would be good if at least the first 4 patches end up in v4.5, as
    they contain DT bindings, and a hard dependency for some DTS
    updates,
  - If the 3 SH patches 24-26, and patch 27 go in together, this can be
    done in the same release. Else the SH patches may have to wait for
    v4.6, and patch 27 for v4.7.
  - Greg has provided his ack for most patches (minus the SH-specific,
    and the 2 new patches), and is OK for the patches going in through
    another tree, so these could go in through Simon's tree as well,
      - If these patches go in through Greg's tree, the DTS updates with
	a hard dependency on the first patch have to wait for v4.6,
      - If these patches go in through Simon's tree, the DTS updates
	with a hard dependency on the first patch can go in v4.5, too,
  - Note that some of the DTS updates have to wait for v4.6 due to other
    dependencies (pinctrl, more info in the integration series),
  - Note that there are a few unrelated sh-sci fixes floating around.
    I think these should go through Greg's tree anyway (they are
    unrelated, and I don't think these cause conflicts).

Greg/Simon, what do you think?

I've also pushed this series (against v4.4-rc1) to the
topic/scif-clk-sck-brg-core-v3 branch of my renesas-drivers git
repository at
https://git.kernel.org/cgit/linux/kernel/git/geert/renesas-drivers.git

For testing, you best use the renesas-drivers-2015-12-14-v4.4-rc5 tag,
as it includes the integration part.

Thanks for applying!

Geert Uytterhoeven (23):
  serial: sh-sci: Add fallback compatibility strings
  serial: sh-sci: Update DT binding documentation for external clock
    input
  serial: sh-sci: Update DT binding documentation for BRG support
  serial: sh-sci: Drop useless check for zero sampling_rate
  serial: sh-sci: Grammar s/Get ... for/Get ... from/
  serial: sh-sci: Use existing local variable in sci_parse_dt()
  serial: sh-sci: Drop unused frame_len parameter for
    sci_baud_calc_hscif()
  serial: sh-sci: Don't overwrite clock selection in
    serial_console_write()
  serial: sh-sci: Convert from clk_get() to devm_clk_get()
  serial: sh-sci: Make unsigned values in sci_baud_calc_hscif() unsigned
  serial: sh-sci: Avoid overflow in sci_baud_calc_hscif()
  serial: sh-sci: Improve bit rate error calculation for HSCIF
  serial: sh-sci: Avoid calculating the receive margin for HSCIF
  serial: sh-sci: Merge sci_scbrr_calc() and sci_baud_calc_hscif()
  serial: sh-sci: Take into account sampling rate for max baud rate
  serial: sh-sci: Add BRG register definitions
  serial: sh-sci: Replace struct sci_port_info by type/regtype encoding
  serial: sh-sci: Correct SCIF type on RZ/A1H
  serial: sh-sci: Correct SCIF type on R-Car for BRG
  serial: sh-sci: Prepare for multiple sampling clock sources
  serial: sh-sci: Add support for optional external (H)SCK input
  serial: sh-sci: Add support for optional BRG on (H)SCIF
  sh: sh7734: Correct SCIF type for BRG

Laurent Pinchart (4):
  serial: sh-sci: Drop the interface clock
  sh: Rename sci_ick and sci_fck clock to fck
  sh: Remove sci_ick clock alias
  serial: sh-sci: Drop the sci_fck clock fallback

 .../bindings/serial/renesas,sci-serial.txt         |  32 +-
 arch/sh/kernel/cpu/clock-cpg.c                     |   1 -
 arch/sh/kernel/cpu/sh2a/clock-sh7264.c             |   9 +-
 arch/sh/kernel/cpu/sh2a/clock-sh7269.c             |  16 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7343.c             |   8 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7366.c             |   6 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7723.c             |  12 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7734.c             |  12 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7757.c             |   6 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7785.c             |  12 +-
 arch/sh/kernel/cpu/sh4a/clock-sh7786.c             |  12 +-
 arch/sh/kernel/cpu/sh4a/clock-shx3.c               |   8 +-
 arch/sh/kernel/cpu/sh4a/setup-sh7734.c             |  12 +-
 drivers/tty/serial/sh-sci.c                        | 555 +++++++++++++++------
 drivers/tty/serial/sh-sci.h                        |  10 +
 include/linux/serial_sci.h                         |   1 +
 16 files changed, 500 insertions(+), 212 deletions(-)

-- 
1.9.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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