drm: renesas: shmobile: Add DT support

Add DT support, by:
1. Creating a panel bridge from DT, and attaching it to the encoder,
2. Replacing the custom connector with a bridge connector,
3. Obtaining clock configuration based on the compatible value.

Note that for now the driver uses a fixed clock configuration selecting
the bus clock, as the current code to select other clock inputs needs
changes to support any other SoCs than SH7724.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/6185ab76aa300fa402e4f6610b2109665f2d8a1c.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Remove internal CRTC state tracking

Now the suspend/resume methods no longer need to look at internal driver
state, the dpms and started fields in the shmob_drm_crtc structure can
be removed, as well as the shmob_drm_crtc_dpms() wrapper. After this,
shmob_drm_crtc_atomic_{en,dis}able() became just wrappers around
shmob_drm_crtc_st{art,op}(), so inline the latter.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/905b9ca72f43d40438c8cb1199cde140eb123204.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Use suspend/resume helpers

Replace the custom suspend/resume handling by calls into
drm_mode_config_helper_{suspend,resume}().

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/a52147ca6033e0a59675f37f0326c7404fc5919c.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Atomic conversion part 1

Implement atomic mode setting for both the primary and overlay planes.
This involves:
- Moving the primary plane handling code from CRTC mode setting to
plane handling shared by primary and overlay planes,
- Adding basic CRTC and mode config atomic mode setting ops, which
don't do much yet.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/a6b698a1c8c1eaf631c2f928f5888ab5fe7aa4c3.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Wait for page flip when turning CRTC off

Turning a CRTC off will prevent a queued page flip from ever completing,
potentially confusing userspace. Wait for queued page flips to complete
before turning the CRTC off to avoid this.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/c97d5859c43fa36043c61de28d67688ebe345092.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Rename shmob_drm_connector.connector

Rename the "connector" member of the shmob_drm_connector subclass
structure to "base", to improve readability.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2382c4c796b53b5d2b24f99b85954ce632f21b90.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Rename shmob_drm_crtc.crtc

Rename the "crtc" member of the shmob_drm_crtc subclass structure to
"base", to improve readability.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/b42a32082d25bde6db7a57d8dc0d9f45820f6716.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Use struct videomode in platform data

Replace the drm_mode_modeinfo field with videomode that includes more
signal polarity flags. This simplifies driver handling of panel modes
and prepares for DT support.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[geert: Simplify]
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/4312e56de424d94399c6105e7159317eae86c9d5.1694767209.git.geert+renesas@glider.be

drm: renesas: shmobile: Remove backlight support

Backlight support should be implemented by panels, not by the LCDC
driver. As the feature is currently unused anyway, remove it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[geert: Cleanups]
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/69707650245bc2193d072f24723d4d5482ea590b.1694767209.git.geert+renesas@glider.be

drm: Place Renesas drivers in a separate dir

Create vendor specific renesas directory and move renesas drivers
to that directory.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Acked-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>