[PATCH v6 1/2] iio: accel: bmc150: Document duplicate ACPI entries with bmi323 driver

[Jonathan LoBue <jlobue10@gmail.com>]

From: jlobue10 <jlobue10@gmail.com>

Adds a description of the duplicate ACPI identifier issue
between devices using bmc150 and bmi323.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Co-developed-by: Luke D. Jones <luke@ljones.dev>
Signed-off-by: Luke D. Jones <luke@ljones.dev>
Co-developed-by: Denis Benato <benato.denis96@gmail.com>
Signed-off-by: Denis Benato <benato.denis96@gmail.com>
Co-developed-by: Antheas Kapenekakis <lkml@antheas.dev>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Signed-off-by: Jonathan LoBue <jlobue10@gmail.com>
---
 drivers/iio/accel/bmc150-accel-i2c.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c
index ee1ba134ad42..353271e23235 100644
--- a/drivers/iio/accel/bmc150-accel-i2c.c
+++ b/drivers/iio/accel/bmc150-accel-i2c.c
@@ -224,6 +224,19 @@ static const struct acpi_device_id bmc150_accel_acpi_match[] = {
 	{"BMA250E"},
 	{"BMC150A"},
 	{"BMI055A"},
+	/*
+ 	 * The "BOSC0200" identifier used here is not unique to devices using
+ 	 * bmc150. The same "BOSC0200" identifier is found in the ACPI tables of
+ 	 * the ASUS ROG ALLY and Ayaneo AIR Plus which both use a Bosch BMI323
+ 	 * chip. This creates a conflict with duplicate ACPI identifiers which
+ 	 * multiple drivers want to use. Fortunately, when the bmc150 driver
+ 	 * starts to load on the ASUS ROG ALLY, the chip ID check portion fails
+ 	 * (correctly) because the chip IDs received (via i2c) are unique between
+ 	 * bmc150 and bmi323 and a dmesg output similar to this:
+ 	 * "bmc150_accel_i2c i2c-BOSC0200:00: Invalid chip 0" can be seen.
+ 	 * This allows the bmi323 driver to take over for ASUS ROG ALLY, and
+ 	 * other devices using the bmi323 chip.
+ 	 */
 	{"BOSC0200"},
 	{"BSBA0150"},
 	{"DUAL250E"},
-- 
2.43.0