[v2,00/11] serial: mvebu-uart: Fixes and new support for higher baudrates

This patch series fixes mvebu-uart driver used on Marvell Armada 37xx
boards and add support for baudrates higher than 230400.

In v2 was added patch with DIV_U64_ROUND_CLOSEST helper and changed
patch "implement UART clock driver for configuring UART base clock" to
fix compile errors on 32-bit archs, including usage of new math helper.

Pali Rohár (11):
  serial: mvebu-uart: fix calculation of clock divisor
  serial: mvebu-uart: do not allow changing baudrate when uartclk is not
    available
  serial: mvebu-uart: correctly calculate minimal possible baudrate
  dt-bindings: mvebu-uart: fix documentation
  arm64: dts: marvell: armada-37xx: Fix reg for standard variant of UART
  serial: mvebu-uart: remove unused member nb from struct mvebu_uart
  math64: New DIV_U64_ROUND_CLOSEST helper
  serial: mvebu-uart: implement UART clock driver for configuring UART
    base clock
  dt-bindings: mvebu-uart: document DT bindings for
    marvell,armada-3700-uart-clock
  arm64: dts: marvell: armada-37xx: add device node for UART clock and
    use it
  serial: mvebu-uart: implement support for baudrates higher than 230400

 .../bindings/clock/armada3700-uart-clock.txt  |  24 +
 .../devicetree/bindings/serial/mvebu-uart.txt |  15 +-
 .../arm64/boot/dts/marvell/armada-3720-db.dts |   4 +
 .../dts/marvell/armada-3720-espressobin.dtsi  |   4 +
 .../dts/marvell/armada-3720-turris-mox.dts    |   4 +
 .../boot/dts/marvell/armada-3720-uDPU.dts     |   4 +
 arch/arm64/boot/dts/marvell/armada-37xx.dtsi  |  17 +-
 drivers/tty/serial/Kconfig                    |   1 +
 drivers/tty/serial/mvebu-uart.c               | 605 +++++++++++++++++-
 include/linux/math64.h                        |  13 +
 10 files changed, 661 insertions(+), 30 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/armada3700-uart-clock.txt

Hi Pali,

On Fri, Jun 25, 2021 at 4:37 PM Pali Rohár <pali@kernel.org> wrote:
> Provide DIV_U64_ROUND_CLOSEST helper which uses div_u64 to perform
> division rounded to the closest integer using unsigned 64bit
> dividend and unsigned 32bit divisor.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>

Thanks for your patch!

> --- a/include/linux/math64.h
> +++ b/include/linux/math64.h
> @@ -281,6 +281,19 @@ u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div);
>  #define DIV64_U64_ROUND_CLOSEST(dividend, divisor)     \
>         ({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
>
> +/*
> + * DIV_U64_ROUND_CLOSEST - unsigned 64bit divide with 32bit divisor rounded to nearest integer
> + * @dividend: unsigned 64bit dividend
> + * @divisor: unsigned 32bit divisor
> + *
> + * Divide unsigned 64bit dividend by unsigned 32bit divisor
> + * and round to closest integer.
> + *
> + * Return: dividend / divisor rounded to nearest integer
> + */
> +#define DIV_U64_ROUND_CLOSEST(dividend, divisor)       \
> +       ({ u32 _tmp = (divisor); div_u64((u64)(dividend) + _tmp / 2, _tmp); })

Given "dividend" should already be an unsigned 64-bit value, I don't
think the cast to "u64" is needed. Similar macros in this file also
don't have the cast.

> +
>  /*
>   * DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer
>   * @dividend: signed 64bit dividend

With the above nit fixed:
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert