[PATCH 00/25] serial: sh-sci: Add external clock and BRG Support

[Geert Uytterhoeven]

	Hi,

This patch series adds support to the Renesas SCI serial driver for
  - the optional external clock on (H)SCI(F) and some SCIFA, where this
    pin can serve as a clock input,
  - 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. Please see the descriptions of the DTS patches for more detailed
information regarding the impact on the supported platforms.

For now this supports r8a7791/koelsch and r8a7795/salvator-x only, which
have an external SCIF_CLK running at 14.7456 MHz.
Support for other R-Car platforms will be added later.

Testing:
  - The Baud Rate Generator for External Clock (BRG) was tested with
    SCIF and HSCIF on r8a7791/koelsch and r8a7795/salvator-x,
  - The external clock input on (H)SCK was tested on r8a7795/salvator-x
    by feeding an external clock signal to (H)SCIF1,
  - Various bit rates were monitored using a SmartScope,
  - Regression testing was done on Renesas ARM platforms that use SCIFA
    as the console (r8a73a4/ape6evm, r8a7740/armadillo, and
    sh73a0/kzm9g).
	      
Dependencies:
  - This series depends on the series "[PATCH v2 00/16] serial: sh-sci:
    Clock Cleanups",
  - The SH patch 25 depends on the "serial: sh-sci" patches in this
    series,
  - The DTS patches 21-24 can be applied independently, once the DT
    binding patches 1-2 are accepted,
  - r8a7791/r8a7795 has a runtime dependency on series "[PATCH 0/2]
    pinctrl: sh-pfc: r8a7791/r8a7795: Add SCIF_CLK support",
  - r8a7795 also depends on
       - platform support in e.g. renesas-drivers-2015-11-17-v4.4-rc1,
       - "[PATCH] pinctrl: sh-pfc: r8a7795: Add HSCIF pins, groups, and
	 functions",
       - "[PATCH] arm64: renesas: r8a7795 dtsi: Add all HSCIF nodes".
  - Legacy SH has a runtime dependency on:
      - series "[PATCH 0/2] drivers: sh: clk: Cleanup clock API",

Thanks for your comments!

Geert Uytterhoeven (25):
  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: 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 clocks and baud rate generators
  serial: sh-sci: Add support for optional external (H)SCK input
  serial: sh-sci: Add support for optional BRG on (H)SCIF
  ARM: shmobile: r8a7791 dtsi: Add BRG support for (H)SCIF
  ARM: shmobile: koelsch dts: Enable SCIF_CLK frequency and pins
  arm64: renesas: r8a7795 dtsi: Add BRG support for (H)SCIF
  arm64: renesas: salvator-x dts: Enable SCIF_CLK frequency and pins
  sh: sh7734: Correct SCIF type for BRG

 .../bindings/serial/renesas,sci-serial.txt         |   9 +
 arch/arm/boot/dts/r8a7791-koelsch.dts              |  13 +
 arch/arm/boot/dts/r8a7791.dtsi                     |  54 ++-
 arch/arm64/boot/dts/renesas/r8a7795-salvator-x.dts |  12 +
 arch/arm64/boot/dts/renesas/r8a7795.dtsi           |  74 ++-
 arch/sh/kernel/cpu/sh4a/setup-sh7734.c             |  12 +-
 drivers/tty/serial/sh-sci.c                        | 530 +++++++++++++++------
 drivers/tty/serial/sh-sci.h                        |   5 +
 include/linux/serial_sci.h                         |   1 +
 9 files changed, 508 insertions(+), 202 deletions(-)

-- 
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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