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From: Jesus Gonzalez <jesusmgh@gmail.com>
To: andriy.shevchenko@linux.intel.com,
	jic23@kernel.org,
	lars@metafoo.de
Cc: linux-iio@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Jesus Gonzalez <jesusmgh@gmail.com>
Subject: [PATCH v3 1/1] Add 10EC5280 to bmi160_i2c ACPI IDs to allow binding on some devices
Date: Tue,  6 Feb 2024 18:11:33 +0100
Message-ID: <20240206171132.35000-2-jesusmgh@gmail.com>
In-Reply-To: <ZcIniuk0TMAIrHIB@smile.fi.intel.com>
References: <ZcIniuk0TMAIrHIB@smile.fi.intel.com>
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"10EC5280" is used by several manufacturers like Lenovo, GPD, or AYA (and
probably others) in their ACPI table as the ID for the bmi160 IMU. This
means the bmi160_i2c driver won't bind to it, and the IMU is unavailable
to the user. Manufacturers have been approached on several occasions to
try getting a BIOS with a fixed ID, mostly without actual positive
results, and since affected devices are already a few years old, this is
not expected to change. This patch enables using the bmi160_i2c driver for
the bmi160 IMU on these devices.

Here is the relevant extract from the DSDT of a GPD Win Max 2 (AMD 6800U
model) with the latest firmware 1.05 installed. GPD sees this as WONTFIX
with the argument of the device working with the Windows drivers.

	Device (BMA2)
	{
	    Name (_ADR, Zero)  // _ADR: Address
	    Name (_HID, "10EC5280")  // _HID: Hardware ID
	    Name (_CID, "10EC5280")  // _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 (0x0069, ControllerInitiated, 0x00061A80,
		        AddressingMode7Bit, "\\_SB.I2CC",
		        0x00, ResourceConsumer, , Exclusive,
		        )
		})
		Return (RBUF) /* \_SB_.I2CC.BMA2._CRS.RBUF */
	    }
	    
	    ...
	    
	}

Signed-off-by: Jesus Gonzalez <jesusmgh@gmail.com>
---
v3: - Add ID to the actual i2c driver instead of the spi driver
(Mistake while manually transferring change to clean master, lesson learned)
    - Move comment to outside of the function as per coding style
    - Adapt comment style to standard multi-line comment style
    - Reduce unnecessary noise from DSDT in the explanation body


 drivers/iio/imu/bmi160/bmi160_i2c.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/iio/imu/bmi160/bmi160_i2c.c b/drivers/iio/imu/bmi160/bmi160_i2c.c
index 81652c08e644..fc72445204e6 100644
--- a/drivers/iio/imu/bmi160/bmi160_i2c.c
+++ b/drivers/iio/imu/bmi160/bmi160_i2c.c
@@ -42,7 +42,16 @@ static const struct i2c_device_id bmi160_i2c_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, bmi160_i2c_id);
 
+/*
+ * FIRMWARE BUG WORKAROUND: ID "10EC5280"
+ * Some manufacturers like GPD, Lenovo or Aya used the incorrect
+ * ID "10EC5280" for bmi160 in their DSDT. A fixed firmware is not
+ * available as of Feb 2024 after trying to work with OEMs, and
+ * this is not expected to change anymore since at least some of
+ * the affected devices are from 2021/2022.
+ */
 static const struct acpi_device_id bmi160_acpi_match[] = {
+	{"10EC5280", 0},
 	{"BMI0160", 0},
 	{ },
 };
-- 
2.43.0