iio: imu: bmi160: add support for bmi120

Add support for bmi120 low power variant of bmi160.
Relax failure to match ID to a warning rather than probe fail.
This allows for fallback compatibles, whilst retaining a useful
debugging message if they turn out not to be so compatible due to
badly behaved firmware.
Signed-off-by: Danila Tikhonov <danila@jiaxyga.com>
Co-developed-by: Barnabás Czémán <trabarni@gmail.com>
Signed-off-by: Barnabás Czémán <trabarni@gmail.com>
Link: https://lore.kernel.org/r/20240505-bmi120-v3-1-15cee3d0b2ef@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/bmi160/bmi160_core.c

@@ -26,6 +26,7 @@
 #include "bmi160.h"
 
 #define BMI160_REG_CHIP_ID	0x00
+#define BMI120_CHIP_ID_VAL	0xD3
 #define BMI160_CHIP_ID_VAL	0xD1
 
 #define BMI160_REG_PMU_STATUS	0x03
@@ -112,6 +113,11 @@
 	.ext_info = bmi160_ext_info,				\
 }
 
+static const u8 bmi_chip_ids[] = {
+	BMI120_CHIP_ID_VAL,
+	BMI160_CHIP_ID_VAL,
+};
+
 /* scan indexes follow DATA register order */
 enum bmi160_scan_axis {
 	BMI160_SCAN_EXT_MAGN_X = 0,
@@ -704,6 +710,16 @@ static int bmi160_setup_irq(struct iio_dev *indio_dev, int irq,
 	return bmi160_probe_trigger(indio_dev, irq, irq_type);
 }
 
+static int bmi160_check_chip_id(const u8 chip_id)
+{
+	for (int i = 0; i < ARRAY_SIZE(bmi_chip_ids); i++) {
+		if (chip_id == bmi_chip_ids[i])
+			return 0;
+	}
+
+	return -ENODEV;
+}
+
 static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
 {
 	int ret;
@@ -737,12 +753,10 @@ static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
 		dev_err(dev, "Error reading chip id\n");
 		goto disable_regulator;
 	}
-	if (val != BMI160_CHIP_ID_VAL) {
-		dev_err(dev, "Wrong chip id, got %x expected %x\n",
-			val, BMI160_CHIP_ID_VAL);
-		ret = -ENODEV;
-		goto disable_regulator;
-	}
+
+	ret = bmi160_check_chip_id(val);
+	if (ret)
+		dev_warn(dev, "Chip id not found: %x\n", val);
 
 	ret = bmi160_set_mode(data, BMI160_ACCEL, true);
 	if (ret)

drivers/iio/imu/bmi160/bmi160_i2c.c

@@ -37,6 +37,7 @@ static int bmi160_i2c_probe(struct i2c_client *client)
 }
 
 static const struct i2c_device_id bmi160_i2c_id[] = {
+	{"bmi120", 0},
 	{"bmi160", 0},
 	{}
 };
@@ -52,12 +53,14 @@ static const struct acpi_device_id bmi160_acpi_match[] = {
 	 * the affected devices are from 2021/2022.
 	 */
 	{"10EC5280", 0},
+	{"BMI0120", 0},
 	{"BMI0160", 0},
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, bmi160_acpi_match);
 
 static const struct of_device_id bmi160_of_match[] = {
+	{ .compatible = "bosch,bmi120" },
 	{ .compatible = "bosch,bmi160" },
 	{ },
 };

drivers/iio/imu/bmi160/bmi160_spi.c

@@ -34,18 +34,21 @@ static int bmi160_spi_probe(struct spi_device *spi)
 }
 
 static const struct spi_device_id bmi160_spi_id[] = {
+	{"bmi120", 0},
 	{"bmi160", 0},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, bmi160_spi_id);
 
 static const struct acpi_device_id bmi160_acpi_match[] = {
+	{"BMI0120", 0},
 	{"BMI0160", 0},
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, bmi160_acpi_match);
 
 static const struct of_device_id bmi160_of_match[] = {
+	{ .compatible = "bosch,bmi120" },
 	{ .compatible = "bosch,bmi160" },
 	{ },
 };