The upstream S6E63M0 driver has some peculiarities around
the prepare/enable disable/unprepare sequence: the screen
is taken out of sleep in prepare() as part of
s6e63m0_init() the put to on with MIPI_DCS_SET_DISPLAY_ON
in enable().

However it is just put into sleep mode directly in
disable(). As disable()/enable() can be called without
unprepare()/prepare() being called, this is unbalanced,
we should take the display out of sleep in enable()
then turn it off().

Further MIPI_DCS_SET_DISPLAY_OFF is never called
balanced with MIPI_DCS_SET_DISPLAY_ON.

The vendor driver for Samsung GT-I8190 (Golden) does all
of these things in strict order.

Augment the driver to do exit sleep/set display on in
enable() and set display off/enter sleep in disable().

Further send an explicit reset pulse in power_on() so we
come up in a known state, and issue the MCS_ERROR_CHECK
command after setting display on like the vendor driver
does. Also use the timings from the vendor driver in
the sequence.

Doing all of these things makes the display much more
stable on the Samsung GT-I8190 when enabling/disabling
the display pipeline.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Cc: Stephan Gerhold <stephan@gerhold.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200817213906.88207-1-linus.walleij@linaro.org