Re: [RFC][PATCH v1] ACPI / scan: Create platform device for BOSC0200 ACPI nodes

From: Hans de Goede
Date: Tue Oct 30 2018 - 11:27:44 EST


On 30-10-18 15:47, Andy Shevchenko wrote:
On some laptops the ACPI device with BOSC0200 _HID is representing
two accelerometers under one node.

We add an ID to the I2C multi instantiate list to enumerate
all I2C slaves correctly.

I believe that overall the approach here is correct, but I've
several (at least 4 different models) devices which use the
BOSC0200 _HID but with only 1 accelerometer / 1 I2cSerialBus
resource in the _CRS table.

So I believe that you need to add a new optional bool to
struct i2c_inst_data and ignore i2c_acpi_new_device()
returning NULL when this is set (and set it for the second

i2c_unregister_device can handle NULL, so some entries
of the multi->clients[i] array ending up as NULL is not
a problem.

Hmm, I have just realized that there is another issue
which is a real problem, we have stuff like this:

[hans@shalem linux]$ ack BOSC0200 /lib/udev/hwdb.d/60-sensor.hwdb
# match the entire dmi-alias, assuming that the use of a BOSC0200 +

And using i2c-multi-instantiate will change the modalias from
acpi:BOSC0200 to i2c:bmc150_accel breaking this.

One way to fix this would be making sure we only use an
i2c:bmc150_accel modalias for the second device. This will
also allow differentiating between the 2 in hwdb quirks for
devices with 2 accelerometers. But the way we currently
generate modalias-es does not allow doing this in an
easy way. Making this possible will require some changes to
show_modalias() and i2c_device_uevent() in

For reference here is the relevant DSDT blurb from the Yoga 11e:

Device (ACC)
Name (_ADR, Zero) // _ADR: Address
Name (_HID, "BOSC0200") // _HID: Hardware ID
Name (_CID, "BOSC0200") // _CID: Compatible ID
Name (_DDN, "Accelerometer") // _DDN: DOS Device Name
Name (_UID, One) // _UID: Unique ID
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
Name (RBUF, ResourceTemplate ()
I2cSerialBusV2 (0x0019, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.PCI0.I2C3",
0x00, ResourceConsumer, , Exclusive,
I2cSerialBusV2 (0x0018, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.PCI0.I2C3",
0x00, ResourceConsumer, , Exclusive,
Return (RBUF) /* \_SB_.PCI0.I2C3.ACC_._CRS.RBUF */

Reported-by: Jeremy Cline <jeremy@xxxxxxxxxx>
Cc: Steven Presser <steve@xxxxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

The previous approach had been discussed at

This has an obvious regression as per commit 1911f48de0d9 ("iio: accel: bmc150:
Add support for BOSC0200 ACPI device id") there are tables where under same ID
we have different sets of the devices (luckily some of that is possible to

- one accellerometer (250e)
- one accellerometer (222e)
- two accellerometers (???)

The proper enabling of the last case w/o a regression sounds like a DMI based
data for I2C multi instantiate driver along with automatic selection of the latter
whenever user selects bmc150-accel-i2c.c.

We can just use "bmc150_accel" everywhere without problems, i2c_device_id.driver_data
does get set by bmc150-accel-i2c.c but not used. does get used
as the name for the iio-dev but that is purely cosmetic so we can simply use
"bmc150_accel" everywhere as the drivers/iio/accel/bmc150-accel-core.c code
will always auto-detect the actual type anyways. So this bit is not a problem
(unlike the modalias changing).



drivers/acpi/scan.c | 1 +
drivers/iio/accel/bmc150-accel-i2c.c | 1 -
drivers/platform/x86/i2c-multi-instantiate.c | 7 +++++++
3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index bd1c59fb0e17..a8cdae057a47 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1539,6 +1539,7 @@ static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
* which i2c_device_id to use for each resource.
static const struct acpi_device_id i2c_multi_instantiate_ids[] = {
+ {"BOSC0200", },
{"BSG1160", },
{"INT33FE", },
diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c
index 8ffc308d5fd0..9d22a4d9d568 100644
--- a/drivers/iio/accel/bmc150-accel-i2c.c
+++ b/drivers/iio/accel/bmc150-accel-i2c.c
@@ -64,7 +64,6 @@ static const struct acpi_device_id bmc150_accel_acpi_match[] = {
{"BMA250E", bma250e},
{"BMA222E", bma222e},
{"BMA0280", bma280},
- {"BOSC0200"},
{ },
MODULE_DEVICE_TABLE(acpi, bmc150_accel_acpi_match);
diff --git a/drivers/platform/x86/i2c-multi-instantiate.c b/drivers/platform/x86/i2c-multi-instantiate.c
index 5456581b473c..8e763765a05e 100644
--- a/drivers/platform/x86/i2c-multi-instantiate.c
+++ b/drivers/platform/x86/i2c-multi-instantiate.c
@@ -100,6 +100,12 @@ static int i2c_multi_inst_remove(struct platform_device *pdev)
return 0;
+static const struct i2c_inst_data bosc0200_data[] = {
+ { "bmc150_accel", -1 },
+ { "bmc150_accel", -1 },
+ {}
static const struct i2c_inst_data bsg1160_data[] = {
{ "bmc150_accel", 0 },
{ "bmc150_magn", -1 },
@@ -112,6 +118,7 @@ static const struct i2c_inst_data bsg1160_data[] = {
* drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
+ { "BOSC0200", (unsigned long)bosc0200_data },
{ "BSG1160", (unsigned long)bsg1160_data },
{ }