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authorHans de Goede <hdegoede@redhat.com>2024-05-23 16:36:01 +0200
committerHans de Goede <hdegoede@redhat.com>2024-05-27 11:42:57 +0200
commit0b178b02673998f5acca5a0365a8858ca45beedb (patch)
tree16a170742100c7d2fa4a78a8772028eb1f6774ef /Documentation
parent5d059bf2b1c4d5779a4c09ec418e40eded44a187 (diff)
downloadlwn-0b178b02673998f5acca5a0365a8858ca45beedb.tar.gz
lwn-0b178b02673998f5acca5a0365a8858ca45beedb.zip
platform/x86: touchscreen_dmi: Add support for setting touchscreen properties from cmdline
On x86/ACPI platforms touchscreens mostly just work without needing any device/model specific configuration. But in some cases (mostly with Silead and Goodix touchscreens) it is still necessary to manually specify various touchscreen-properties on a per model basis. touchscreen_dmi is a special place for DMI quirks for this, but it can be challenging for users to figure out the right property values, especially for Silead touchscreens where non of these can be read back from the touchscreen-controller. ATM users can only test touchscreen properties by editing touchscreen_dmi.c and then building a completely new kernel which makes it unnecessary difficult for users to test and submit properties when necessary for their laptop / tablet model. Add support for specifying properties on the kernel commandline to allow users to easily figure out the right settings. See the added documentation in kernel-parameters.txt for the commandline syntax. Cc: Gregor Riepl <onitake@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20240523143601.47555-1-hdegoede@redhat.com
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt22
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 500cfa776225..b600df82669d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1921,6 +1921,28 @@
Format:
<bus_id>,<clkrate>
+ i2c_touchscreen_props= [HW,ACPI,X86]
+ Set device-properties for ACPI-enumerated I2C-attached
+ touchscreen, to e.g. fix coordinates of upside-down
+ mounted touchscreens. If you need this option please
+ submit a drivers/platform/x86/touchscreen_dmi.c patch
+ adding a DMI quirk for this.
+
+ Format:
+ <ACPI_HW_ID>:<prop_name>=<val>[:prop_name=val][:...]
+ Where <val> is one of:
+ Omit "=<val>" entirely Set a boolean device-property
+ Unsigned number Set a u32 device-property
+ Anything else Set a string device-property
+
+ Examples (split over multiple lines):
+ i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
+ touchscreen-inverted-y
+
+ i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
+ touchscreen-size-y=1080:touchscreen-inverted-y:
+ firmware-name=gsl1680-vendor-model.fw:silead,home-button
+
i8042.debug [HW] Toggle i8042 debug mode
i8042.unmask_kbd_data
[HW] Enable printing of interrupt data from the KBD port