Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-11-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Peter Jones <pjones@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-10-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-9-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-8-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-7-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-6-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-5-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-4-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-3-tzimmermann@suse.de
Set struct fb_ops and with FB_DEFAULT_IOMEM_OPS, fbdev's initializer
for I/O memory. Sets the callbacks to the cfb_ and fb_io_ functions.
Select the correct modules with Kconfig's FB_IOMEM_HELPERS token.
The macro and token set the currently selected values, so there is
no functional change.
v3:
* use _IOMEM_ in commit message
v2:
* updated to use _IOMEM_ tokens
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803184034.6456-2-tzimmermann@suse.de
The Jasonic JT240MHQS-HWT-EK-E3 is a custom panel using the Sitronix
ST7789V controller. While the controller features a resolution of
320x240, only an area of 280x240 is visible by design.
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718-feature-lcd-panel-v2-4-2485ca07b49d@wolfvision.net
The ST7789V controller features support for the partial mode. Here,
the area to be displayed can be restricted in one direction (by default,
in vertical direction). This is useful for panels that are partially
occluded by design. Add support for the partial mode.
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718-feature-lcd-panel-v2-3-2485ca07b49d@wolfvision.net
The sitronix-st7789v driver now considers the rotation property.
Add the property to the documentation.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718-feature-st7789v-v3-3-157d68fb63e2@wolfvision.net
Determine the orientation of the display based on the device tree and
propagate it.
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718-feature-st7789v-v3-2-157d68fb63e2@wolfvision.net
The ELD (EDID-Like Data) is not updated when the HDMI cable
is plugged into different HDMI monitors.
This is because the EDID is not updated in the HDMI HPD function.
As a result, the ELD data remains unchanged and may not reflect
the capabilities of the newly connected HDMI sink device.
To address this issue, the handle_plugged_change function should move to
the bridge_atomic_enable and bridge_atomic_disable functions.
Make sure the EDID is properly updated before updating ELD.
Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804061145.2824843-1-Sandor.yu@nxp.com
This code doesn't check for lsdc_bo_create() failure and it could lead
to a crash. It can fail for a variety of reasons, but the most common
cause would be low memory. Add a check.
Fixes: f39db26c54 ("drm: Add kms driver for loongson display controller")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Link: https://patchwork.freedesktop.org/patch/msgid/ZLeijglIMPve2Iio@kadam
When a symbol is selected that has extra dependencies,
anything that selects it must have the same dependencies.
With the added CONFIG_DRM reference from I2C_HID_CORE,
this broke a couple of drivers that now also depend
on DRM:
WARNING: unmet direct dependencies detected for I2C_HID_CORE
Depends on [m]: HID_SUPPORT [=y] && I2C_HID [=y] && (DRM [=m] || !DRM [=m])
Selected by [y]:
- I2C_HID_OF [=y] && HID_SUPPORT [=y] && I2C_HID [=y]
- I2C_HID_ACPI [=y] && HID_SUPPORT [=y] && I2C_HID [=y] && ACPI [=y]
- I2C_HID_OF_GOODIX [=y] && HID_SUPPORT [=y] && I2C_HID [=y] && OF [=y]
x86_64-linux-ld: vmlinux.o: in function `i2c_hid_core_remove':
(.text+0xfc8826): undefined reference to `drm_panel_remove_follower'
x86_64-linux-ld: vmlinux.o: in function `i2c_hid_core_probe':
(.text+0xfc8da0): undefined reference to `drm_is_panel_follower'
Add the corresponding DRM||!DRM dependencies on each one that
is affected.
Fixes: 96a37bfd23 ("HID: i2c-hid: Support being a panel follower")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802124947.1355415-1-arnd@kernel.org
Use fb_info() to print status message at the end of the probe function,
which avoids decoding the devices. fb_info() works with or without an
fbdev kernel device. Fixes the following error:
../drivers/video/fbdev/ps3fb.c: In function 'ps3fb_probe':
../drivers/video/fbdev/ps3fb.c:1172:40: error: 'struct fb_info' has no member named 'dev'
1172 | dev_driver_string(info->dev), dev_name(info->dev),
| ^~
../include/linux/dev_printk.h:110:37: note: in definition of macro 'dev_printk_index_wrap'
110 | _p_func(dev, fmt, ##__VA_ARGS__); \
| ^~~~~~~~~~~
../drivers/video/fbdev/ps3fb.c:1171:9: note: in expansion of macro 'dev_info'
1171 | dev_info(info->device, "%s %s, using %u KiB of video memory\n",
| ^~~~~~~~
../drivers/video/fbdev/ps3fb.c:1172:61: error: 'struct fb_info' has no member named 'dev'
1172 | dev_driver_string(info->dev), dev_name(info->dev),
| ^~
../include/linux/dev_printk.h:110:37: note: in definition of macro 'dev_printk_index_wrap'
110 | _p_func(dev, fmt, ##__VA_ARGS__); \
| ^~~~~~~~~~~
../drivers/video/fbdev/ps3fb.c:1171:9: note: in expansion of macro 'dev_info'
1171 | dev_info(info->device, "%s %s, using %u KiB of video memory\n",
| ^~~~~~~~
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/lkml/ccc63065-2976-88ef-1211-731330bf2866@infradead.org/
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 701d2054fa ("fbdev: Make support for userspace interfaces configurable")
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://patchwork.freedesktop.org/patch/msgid/20230731175535.11345-1-tzimmermann@suse.de
Since commit 6b85aa68d9 ("drm: Enable PRIME import/export for all
drivers"), import/export is always supported. Document this so that
user-space knows what to expect.
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20230712183156.191445-1-contact@emersion.fr
Convert struct drm_event to a kernel doc comment. Link to the
generic DRM event types. Add a basic description of each event
type.
Signed-off-by: Simon Ser <contact@emersion.fr>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20230717093032.600773-1-contact@emersion.fr
When I originally wrote these docs, I couldn't manage to insert a
cross-reference to a section. Here's how it can be done.
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Pekka Paalanen <pekka.paalanen@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230803095734.386761-1-contact@emersion.fr
CEC interrupt status/mask and logical address registers
will be reset when device enter suspend.
It will cause cec fail to work after device resume.
Add CEC suspend/resume functions, reinitialize logical address registers
and restore interrupt status/mask registers after resume.
Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230721124415.1513223-1-Sandor.yu@nxp.com
In commit d2aacaf073 ("drm/panel: Check for already prepared/enabled
in drm_panel") the formatting for a code block was not quite
right. This caused an error when building htmldocs:
Documentation/gpu/todo.rst:469: ERROR: Unexpected indentation.
Fix the error by using the proper syntax for a code block.
Fixes: d2aacaf073 ("drm/panel: Check for already prepared/enabled in drm_panel")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20230802141724.0edce253@canb.auug.org.au
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802074727.2.Iaeb7b0f7951aee6b8c090364bbc87b1ae198a857@changeid
In the kernel doc for the `follower_lock` member of `struct drm_panel`
there was a typo where it was called `followers_lock`. This resulted
in a warning when making "htmldocs":
./include/drm/drm_panel.h:270: warning:
Function parameter or member 'follower_lock' not described in 'drm_panel'
Fix the typo.
Fixes: de0874165b ("drm/panel: Add a way for other devices to follow panel state")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20230802142136.0f67b762@canb.auug.org.au
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802074727.1.I4036706ad5e7f45e80d41b777164258e52079cd8@changeid
Pointer pexec is being assigned a value however it is never read. The
assignment is redundant and can be removed. Replace sizeof(*pexec)
with sizeof the type and remove the declaration of pointer pexec.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230726140626.264952-1-colin.i.king@gmail.com
Displays that are connected to the same SPI bus may share the D/C GPIO.
Use GPIOD_FLAGS_BIT_NONEXCLUSIVE to allow access to the same GPIO for
multiple panel-mipi-dbi instances. Exclusive access to the GPIO during
transfers is ensured by the locking in drm_mipi_dbi.c.
Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230724065654.5269-3-otto.pflueger@abscue.de
Multiple displays may be connected to the same bus and share a D/C GPIO,
so the display driver needs exclusive access to the bus to ensure that
it can control the D/C GPIO safely.
Signed-off-by: Otto Pflüger <otto.pflueger@abscue.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230724065654.5269-2-otto.pflueger@abscue.de
DRM bridges are not visible to the userspace and it may not be
immediately clear if the chain is somehow constructed incorrectly. I
have had two separate instances of a bridge driver failing to do a
drm_bridge_attach() call, resulting in the bridge connector not being
part of the chain. In some situations this doesn't seem to cause issues,
but it will if DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is used.
Add a debugfs file to print the bridge chains. For me, on this TI AM62
based platform, I get the following output:
encoder[39]
bridge[0] type: 0, ops: 0x0
bridge[1] type: 0, ops: 0x0, OF: /bus@f0000/i2c@20000000/dsi@e:toshiba,tc358778
bridge[2] type: 0, ops: 0x3, OF: /bus@f0000/i2c@20010000/hdmi@48:lontium,lt8912b
bridge[3] type: 11, ops: 0x7, OF: /hdmi-connector:hdmi-connector
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802-drm-bridge-chain-debugfs-v4-1-7e3ae3d137c0@ideasonboard.com
Turning on an i2c-hid device can be a slow process. This is why
i2c-hid devices use PROBE_PREFER_ASYNCHRONOUS. Unfortunately, when
we're a panel follower the i2c-hid power up sequence now blocks the
power on of the panel. Let's fix that by scheduling the work on the
system_wq.
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.10.I962bb462ede779005341c49320740ed95810021d@changeid
As talked about in the patch ("drm/panel: Add a way for other devices
to follow panel state"), we really want to keep the power states of a
touchscreen and the panel it's attached to in sync with each other. In
that spirit, add support to i2c-hid to be a panel follower. This will
let the i2c-hid driver get informed when the panel is powered on and
off. From there we can match the i2c-hid device's power state to that
of the panel.
NOTE: this patch specifically _doesn't_ use pm_runtime to keep track
of / manage the power state of the i2c-hid device, even though my
first instinct said that would be the way to go. Specific problems
with using pm_runtime():
* The initial power up couldn't happen in a runtime resume function
since it create sub-devices and, apparently, that's not good to do
in your resume function.
* Managing our power state with pm_runtime meant fighting to make the
right thing happen at system suspend to prevent the system from
trying to resume us only to suspend us again. While this might be
able to be solved, it added complexity.
Overall the code without pm_runtime() ended up being smaller and
easier to understand.
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.9.Ib1a98309c455cd7e26b931c69993d4fba33bbe15@changeid
In the i2c-hid remove() function we currently try to power off,
depopulate our child device, and free our resources. That's OK, but...
* If the i2c-hid device is on a power rail that can't turn off (either
an always-on or a shared power rail) we won't try to put the device
in a low power state during remove(). This probably doesn't matter
for very many devices but it could be nice in some instances.
* If the i2c-hid device somehow manages to generate an interrupt after
we tried to power off it is conceivable that the interrupt could
arrive during or after the call to hid_destroy_device() but before
the call to free_irq(). That could cause a crash since our IRQ
handler isn't expecting it. One could imagine this happening in
the case where we couldn't turn off (see the previous bullet) or,
possibly, if the interrupt line could glitch shortly after the
device powered off.
Let's call the suspend code during remove to avoid these issues. That
will put the device into a low power state and also disable
interrupts.
Technically, one could consider this a "fix" of commit 4a200c3b9a
("HID: i2c-hid: introduce HID over i2c specification implementation").
However, since the above bullet points are more theoretical than
problems seen on real systems and since the remove() of an i2c-hid
touchscreen isn't terribly likely to be called in production, it's
probably not worth the bother of trying to backport it.
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.8.Ic3ecad4a825905f4e4ce2a772b17f3c9cb2d60a2@changeid
In a future patch we'd like to be able to call the current i2c-hid
suspend and resume functions from times other than system
suspend. Move the functions higher up in the file and have them take a
"struct i2c_hid" to make this simpler. We'll then add tiny wrappers of
the functions for use with system suspend.
This change is expected to have no functional effect.
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.7.I5c9894789b8b02f029bf266ae9b4f43c7907a173@changeid
In a future patch, we want to change i2c-hid not to necessarily power
up the touchscreen during probe. In preparation for that, rearrange
the probe function so that we put as much stuff _before_ powering up
the device as possible.
This change is expected to have no functional effect.
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.6.Ifcc9b0a44895d164788966f9b9511fe094ca8cf9@changeid
The SYSTEM_SLEEP_PM_OPS() allows us to get rid of '#ifdef
CONFIG_PM_SLEEP', as talked about in commit 1a3c7bb088 ("PM: core:
Add new *_PM_OPS macros, deprecate old ones").
This change is expected to have no functional effect.
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.5.Ib2a2865bd3c0b068432259dfc7d76cebcbb512be@changeid
Inform fw_devlink of the fact that a panel follower (like a
touchscreen) is effectively a consumer of the panel from the purposes
of fw_devlink.
NOTE: this patch isn't required for correctness but instead optimizes
probe order / helps avoid deferrals.
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.4.Ibf8e1342b5b7906279db2365aca45e6253857bb3@changeid
These days, it's fairly common to see panels that have touchscreens
attached to them. The panel and the touchscreen can somewhat be
thought of as totally separate devices and, historically, this is how
Linux has treated them. However, treating them as separate isn't
necessarily the best way to model the two devices, it was just that
there was no better way. Specifically, there is little practical
reason to have the touchscreen powered on when the panel is turned
off, but if we model the devices separately we have no way to keep the
two devices' power states in sync with each other.
The issue described above makes it sound as if the problem here is
just about efficiency. We're wasting power keeping the touchscreen
powered up when the screen is off. While that's true, the problem can
go deeper. Specifically, hardware designers see that there's no reason
to have the touchscreen on while the screen is off and then build
hardware assuming that software would never turn the touchscreen on
while the screen is off.
In the very simplest case of hardware designs like this, the
touchscreen and the panel share some power rails. In most cases, this
turns out not to be terrible and is, again, just a little less
efficient. Specifically if we tell Linux that the touchscreen and the
panel are using the same rails then Linux will keep the rails on when
_either_ device is turned on. That ends to work OK-ish, but now if you
turn the panel off not only will the touchscreen remain powered, but
the power rails for the panel itself won't be switched off, burning
extra power.
The above two inefficiencies are _extra_ minor when you consider the
fact that laptops rarely spend much time with the screen off. The main
use case would be when an external screen (and presumably a power
supply) is attached.
Unfortunately, it gets worse from here. On sc7180-trogdor-homestar,
for instance, the display's TCON (timing controller) sometimes crashes
if you don't power cycle it whenever you stop and restart the video
stream (like during a modeset). The touchscreen keeping the power
rails on causes real problems. One proposal in the homestar timeframe
was to move the touchscreen to an always-on rail, dedicating the main
power rail to the panel. That caused _different_ problems as talked
about in commit 557e05fa9f ("HID: i2c-hid: goodix: Stop tying the
reset line to the regulator"). The end result of all of this was to
add an extra regulator to the board, increasing cost.
Recently, Cong Yang posted a patch [1] where things are even worse.
The panel and touch controller on that system seem even more
intimately tied together and really can't be thought of separately.
To address this issue, let's start allowing devices to register
themselves as "panel followers". These devices will get called after a
panel has been powered on and before a panel is powered off. This
makes the panel the primary device in charge of the power state, which
matches how userspace uses it.
The panel follower API should be fairly straightforward to use. The
current code assumes that panel followers are using device tree and
have a "panel" property pointing to the panel to follow. More
flexibility and non-DT implementations could be added as needed.
Right now, panel followers can follow the prepare/unprepare functions.
There could be arguments made that, instead, they should follow
enable/disable. I've chosen prepare/unprepare for now since those
functions are guaranteed to power up/power down the panel and it seems
better to start the process earlier.
A bit of explaining about why this is a roll-your-own API instead of
using something more standard:
1. In standard APIs in Linux, parent devices are automatically powered
on when a child needs power. Applying that here, it would mean that
we'd force the panel on any time someone was listening to the
touchscreen. That, unfortunately, would have broken homestar's need
(if we hadn't changed the hardware, as per above) where the panel
absolutely needs to be able to power cycle itself. While one could
argue that homestar is broken hardware and we shouldn't have the
API do backflips for it, _officially_ the eDP timing guidelines
agree with homestar's needs and the panel power sequencing diagrams
show power going off. It's nice to be able to support this.
2. We could, conceibably, try to add a new flag to device_link causing
the parent to be in charge of power. Then we could at least use
normal pm_runtime APIs. This sounds great, except that we run into
problems with initial probe. As talked about in the later patch
("HID: i2c-hid: Support being a panel follower") the initial power
on of a panel follower might need to do things (like add
sub-devices) that aren't allowed in a runtime_resume function.
The above complexities explain why this API isn't using common
functions. That being said, this patch is very small and
self-contained, so if someone was later able to adapt it to using more
common APIs while solving the above issues then that could happen in
the future.
[1] https://lore.kernel.org/r/20230519032316.3464732-1-yangcong5@huaqin.corp-partner.google.com
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.3.Icd5f96342d2242051c754364f4bee13ef2b986d4@changeid
In a whole pile of panel drivers, we have code to make the
prepare/unprepare/enable/disable callbacks behave as no-ops if they've
already been called. It's silly to have this code duplicated
everywhere. Add it to the core instead so that we can eventually
delete it from all the drivers. Note: to get some idea of the
duplicated code, try:
git grep 'if.*>prepared' -- drivers/gpu/drm/panel
git grep 'if.*>enabled' -- drivers/gpu/drm/panel
NOTE: arguably, the right thing to do here is actually to skip this
patch and simply remove all the extra checks from the individual
drivers. Perhaps the checks were needed at some point in time in the
past but maybe they no longer are? Certainly as we continue
transitioning over to "panel_bridge" then we expect there to be much
less variety in how these calls are made. When we're called as part of
the bridge chain, things should be pretty simple. In fact, there was
some discussion in the past about these checks [1], including a
discussion about whether the checks were needed and whether the calls
ought to be refcounted. At the time, I decided not to mess with it
because it felt too risky.
Looking closer at it now, I'm fairly certain that nothing in the
existing codebase is expecting these calls to be refcounted. The only
real question is whether someone is already doing something to ensure
prepare()/unprepare() match and enabled()/disable() match. I would say
that, even if there is something else ensuring that things match,
there's enough complexity that adding an extra bool and an extra
double-check here is a good idea. Let's add a drm_warn() to let people
know that it's considered a minor error to take advantage of
drm_panel's double-checking but we'll still make things work fine.
We'll also add an entry to the official DRM todo list to remove the
now pointless check from the panels after this patch lands and,
eventually, fixup anyone who is triggering the new warning.
[1] https://lore.kernel.org/r/20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.2.I59b417d4c29151cc2eff053369ec4822b606f375@changeid
As talked about in the patch ("drm/panel: Add a way for other devices
to follow panel state"), touchscreens that are connected to panels are
generally expected to be power sequenced together with the panel
they're attached to. Today, nothing provides information allowing you
to find out that a touchscreen is connected to a panel. Let's add a
phandle for this.
The proerty is added to the generic touchscreen bindings and then
enabled in the bindings for the i2c-hid backed devices. This can and
should be added for other touchscreens in the future, but for now
let's start small.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Benjamin Tissoires <bentiss@kernel.org>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727101636.v4.1.Id68e30343bb1e11470582a9078b086176cfec46b@changeid
A very basic debugging rule when a device is connected for the first
time is to access a read-only register which contains known data in
order to ensure the communication protocol is properly working. This
driver lacked any read helper which is often a critical piece for
speeding-up bring-ups.
Add a read helper and use it to verify the communication with the panel
is working as soon as possible in order to inform the user early if this
is not the case.
As this panel may work with no MISO line, the check is discarded in this
case. Upon error, we do not fail probing but just warn the user, in case
the DT description would be lacking the Rx bus width (which is likely on
old descriptions) in order to avoid breaking existing devices.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Tested-by: Sebastian Reichel <sre@kernel.org> # no MISO line
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714013756.1546769-20-sre@kernel.org
