drm/gma500: refactor deprecated strncpy

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

We should prefer more robust and less ambiguous string interfaces.

Since `chan->base.name` is expected to be NUL-terminated, a suitable
replacement is `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer without also unnecessarily
NUL-padding (since `chan` is kzalloc'd already).

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919-drivers-gpu-drm-gma500-oaktrail_lvds_i2c-c-v2-1-9ebe6983b4cb@google.com

drm/gma500: Make oaktrail lvds use ddc adapter from drm_connector

We're moving all uses of ddc_bus to drm_connector where they belong.
The initialization of the gma_i2c_chan for Oaktrail is a bit backwards
so it required improvements. Also cleanup the error handling in
oaktrail_lvds_init(). Since this is the last user of
gma_encoder->ddc_bus we can remove it.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601092311.22648-8-patrik.r.jakobsson@gmail.com

drm/gma500: Make gma_i2c_chan a subclass of i2c_adapter

This makes it easier to get at the full gma_i2c_chan when having an
i2c_adapter from eg. drm_connector->ddc.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601092311.22648-3-patrik.r.jakobsson@gmail.com

drm/gma500: Use gma_ prefix for our i2c abstraction

psb_intel_i2c_chan is used by all chips so use the correct prefix.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601092311.22648-2-patrik.r.jakobsson@gmail.com

drm/gma500: Replace references to dev_private with helper function

Replace most references to struct drm_device.dev_private with the new
helper function to_drm_psb_private(). The only references left are in
assignments and the helper itself.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210920141051.30988-2-tzimmermann@suse.de

drm/gma500/oaktrail_lvds_i2c: Remove unused variables 'tmp'

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c: In function ‘get_clock’:
drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c:69:11: warning: variable ‘tmp’ set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c: In function ‘get_data’:
drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c:83:11: warning: variable ‘tmp’ set but not used [-Wunused-but-set-variable]

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jan Safrata <jan.nikitenko@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115181601.3432599-19-lee.jones@linaro.org

drm/gma500: Remove references to struct drm_device.pdev

Using struct drm_device.pdev is deprecated. Convert gma500 to struct
drm_device.dev. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201103542.2182-8-tzimmermann@suse.de

drm/gma500: drop drmp.h include from all .c files

Drop remaining uses of the deprecated drmP.h in gma500

Replaced drmp.h with forward declarations or include files
as relevant.

Moved all include files to blocks in following order:
\#include <linux/*>

\#include <asm/*>

\#include <drm/*>

\#include ""

And within each block sort the include files alphabetically.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190519195526.3422-6-sam@ravnborg.org

drm/gma500: add support for atom e6xx lpc lvds i2c

add gpio bitbanging i2c adapter on LPC device of atom e6xx
gpu chipset to access lvds EDID
tested on SECO QuadMo747-E6xx-EXTREME Qseven platform

Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Jan Safrata <jan.nikitenko@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>