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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 v2 1/1] Add 10EC5280 to bmi160_i2c ACPI IDs to allow binding on some devices
Date: Mon,  5 Feb 2024 19:36:20 +0100
Message-ID: <20240205183618.7761-3-jesusmgh@gmail.com>
In-Reply-To: <ZcDnikkiwSIDGzT0@smile.fi.intel.com>
References: <ZcDnikkiwSIDGzT0@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.

     Scope (_SB.I2CC)
    {
        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 */
            }

            OperationRegion (CMS2, SystemIO, 0x72, 0x02)
            Field (CMS2, ByteAcc, NoLock, Preserve)
            {
                IND2,   8, 
                DAT2,   8
            }

            IndexField (IND2, DAT2, ByteAcc, NoLock, Preserve)
            {
                Offset (0x74), 
                BACS,   32
            }

            Method (ROMS, 0, NotSerialized)
            {
                Name (RBUF, Package (0x03)
                {
                    "0 -1 0", 
                    "-1 0 0", 
                    "0 0 1"
                })
                Return (RBUF) /* \_SB_.I2CC.BMA2.ROMS.RBUF */
            }

            Method (CALS, 1, NotSerialized)
            {
                Local0 = Arg0
                If (((Local0 == Zero) || (Local0 == Ones)))
                {
                    Return (Local0)
                }
                Else
                {
                    BACS = Local0
                }
            }

            Method (_STA, 0, NotSerialized)  // _STA: Status
            {
                Return (0x0F)
            }
        }
    }

Signed-off-by: Jesus Gonzalez <jesusmgh@gmail.com>
---
v2 patch implementing the improvements mentioned by Mr. Cameron and Mr.
Shevchenko, if I understood them correctly. Please tell me if anything
else should be changed, and I'll be happy to make a new revision.

Thank you!


 drivers/iio/imu/bmi160/bmi160_spi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iio/imu/bmi160/bmi160_spi.c b/drivers/iio/imu/bmi160/bmi160_spi.c
index 8b573ea99af2..f88d4b2ba79b 100644
--- a/drivers/iio/imu/bmi160/bmi160_spi.c
+++ b/drivers/iio/imu/bmi160/bmi160_spi.c
@@ -40,6 +40,14 @@ static const struct spi_device_id bmi160_spi_id[] = {
 MODULE_DEVICE_TABLE(spi, bmi160_spi_id);
 
 static const struct acpi_device_id bmi160_acpi_match[] = {
+	/* FIRMWARE BUG WORKAROUND
+	 * 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.
+	 */
+	{"10EC5280", 0},
 	{"BMI0160", 0},
 	{ },
 };
-- 
2.43.0