drm/tegra: Changes for v6.4-rc1

The majority of this is minor cleanups and fixes. Other than those, this
contains Uwe's conversion to the new driver remove callback and Thomas'
fbdev DRM client conversion. The driver can now also be built on other
architectures to easy compile coverage.

Finally, this adds Mikko as a second maintainer for the driver. As a
next step we also want Tegra DRM to move into drm-misc to streamline the
maintenance process.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230406121404.967704-1-thierry.reding@gmail.com

In tegra_sor_compute_config(), the 32-bit value mode->clock is
multiplied by 1000, and assigned to the u64 variable pclk. We can avoid
a potential 32-bit integer overflow by casting mode->clock to u64 before
we do the arithmetic and assignment.

Signed-off-by: Nur Hussein <hussein@unixcat.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Move code from ad-hoc fbdev callbacks into DRM client functions
and remove the old callbacks. The functions instruct the client
to poll for changed output or restore the display. The DRM core
calls both, the old callbacks and the new client helpers, from
the same places. The new functions perform the same operation as
before, so there's no change in functionality.

Replace all code that initializes or releases fbdev emulation
throughout the driver. Instead initialize the fbdev client by a
single call to tegra_fbdev_setup() after tegra has registered
its DRM device. As in most drivers, tegra's fbdev emulation now
acts like a regular DRM client.

The fbdev client setup consists of the initial preparation and the
hot-plugging of the display. The latter creates the fbdev device
and sets up the fbdev framebuffer. The setup performs display
hot-plugging once. If no display can be detected, DRM probe helpers
re-run the detection on each hotplug event.

A call to drm_dev_unregister() releases the client automatically.
No further action is required within tegra. If the fbdev
framebuffer has been fully set up, struct fb_ops.fb_destroy
implements the release. For partially initialized emulation, the
fbdev client reverts the initial setup.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Initialize the fbdev client in the fbdev code with empty helper
functions. Also clean up the client. The helpers will later
implement various functionality of the DRM client. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Only build tegra's fbdev emulation if CONFIG_DRM_FBDEV_EMULATION
has been enabled. As part of this change, move the code into its
own source file. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Include the device and connector information in the SCDC
debugs. Makes it easier to figure out who did what.

v2: Rely on connector->ddc (Maxime)

Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Emma Anholt <emma@anholt.net>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230403223652.18848-1-ville.syrjala@linux.intel.com
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>

Remove struct tegra_fbdev, which is an empty wrapper around struct
drm_fb_helper. Use the latter directly. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Fbdev's struct fb_helper stores a pointer to the framebuffer. Remove
struct tegra_fbdev.fb, which contains the same value. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Include <linux/i2c.h> to get the contained declarations. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn
Signed-off-by: Thierry Reding <treding@nvidia.com>

Include <linux/of.h> to get the contained declarations. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn
Signed-off-by: Thierry Reding <treding@nvidia.com>