On the raspberry pi, you can disable the serial port to gain dynamic frequency
scaling which can get handy at times.

However, in such a configuration the serial controller gets its rx queue filled
up with zero bytes which then happily get transmitted on to whoever calls
getc() today.

This patch adds detection logic for that case by checking whether the RX pin is
mapped to GPIO15 and disables the mini uart if it is not mapped properly.

That way we can leave the driver enabled in the tree and can determine during
runtime whether serial is usable or not, having a single binary that allows for
uart and non-uart operation.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

This is very likely to be necessary for normal use cases.
Set its default to 'y' for shorter defconfig files.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

[trini: Drop CMD_BOOTI as it's now on by default on ARM64]
Signed-off-by: Tom Rini <trini@konsulko.com>

BLANCHE is development board based on R-Car V2H SoC (R8A7792)

This commit supports the following periherals:
- SCIF, Ethernet, QSPI, MMC

Signed-off-by: Masakazu Mochizuki <masakazu.mochizuki.wd@hitachi.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

This can be used in the same way as other R-CAR serial setting.

Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

This does not have much impact on behavior, but makes code look more
more like Linux.  The use of devm_ioremap() often helps to delete
.remove callbacks entirely.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Read information about clock frequency from DT.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>

Commit 83fd908f28c ("dm: imx: serial: Support DTE mode when using driver
model") breaks the serial output for the imx boards that do not use
the serial driver model.

The reason for the breakage is that it's setting UFCR_DCEDTE
unconditionally for the non-dm case.

So keep the original behavior by removing UFCR_DCEDTE setting in the
non-dm case.

Tested on mx7sabresd and mx6wandboard.

Signed-off-by: Breno Lima <breno.lima@nxp.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>