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media: atomisp_gmin_platform: Add DMI quirk to not turn AXP ELDO2 regulator off on some boards

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The TrekStor SurfTab duo W1 10.1 has a hw bug where turning eldo2 back on
after having turned it off causes the CPLM3218 ambient-light-sensor on
the front camera sensor's I2C bus to crash, hanging the bus.

Add a DMI quirk table for systems on which to leave eldo2 on.

Note an alternative fix is to turn off the CPLM3218 ambient-light-sensor
as long as the camera sensor is being used, this is what Windows seems
to do as a workaround (based on analyzing the DSDT). But that is not
easy to do cleanly under Linux.

Link: https://lore.kernel.org/linux-media/20220116215204.307649-10-hdegoede@redhat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Hans de Goede 2022-01-16 22:52:04 +01:00 committed by Mauro Carvalho Chehab
parent f88fba1a41
commit 2c39a01154
1 changed files with 18 additions and 0 deletions
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18
drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
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@ -761,6 +761,21 @@ static int axp_regulator_set(struct device *dev, struct gmin_subdev *gs,
return 0;
}
/*
* Some boards contain a hw-bug where turning eldo2 back on after having turned
* it off causes the CPLM3218 ambient-light-sensor on the image-sensor's I2C bus
* to crash, hanging the bus. Do not turn eldo2 off on these systems.
*/
static const struct dmi_system_id axp_leave_eldo2_on_ids[] = {
{
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TrekStor"),
DMI_MATCH(DMI_PRODUCT_NAME, "SurfTab duo W1 10.1 (VT4)"),
},
},
{ }
};
static int axp_v1p8_on(struct device *dev, struct gmin_subdev *gs)
{
int ret;
@ -790,6 +805,9 @@ static int axp_v1p8_off(struct device *dev, struct gmin_subdev *gs)
if (ret)
return ret;
if (dmi_check_system(axp_leave_eldo2_on_ids))
return 0;
ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
ELDO_CTRL_REG, gs->eldo2_ctrl_shift, false);
return ret;