iio: magnetometer: ak8975: Add AK09118 support

Add additional AK09118 to the magnetometer driver which has the same
register mapping and scaling as the AK09112 device.
Signed-off-by: Danila Tikhonov <danila@jiaxyga.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
Link: https://patch.msgid.link/20240819-ak09918-v4-4-f0734d14cfb9@mainlining.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/magnetometer/Kconfig

@@ -39,7 +39,7 @@ config AK8975
 	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for Asahi Kasei AK8975, AK8963,
-	  AK09911, AK09912 or AK09916 3-Axis Magnetometer.
+	  AK09911, AK09912, AK09916 or AK09918 3-Axis Magnetometer.
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called ak8975.

drivers/iio/magnetometer/ak8975.c

@@ -78,6 +78,7 @@
  */
 #define AK09912_REG_WIA1		0x00
 #define AK09912_REG_WIA2		0x01
+#define AK09918_DEVICE_ID		0x0C
 #define AK09916_DEVICE_ID		0x09
 #define AK09912_DEVICE_ID		0x04
 #define AK09911_DEVICE_ID		0x05
@@ -209,6 +210,7 @@ enum asahi_compass_chipset {
 	AK09911,
 	AK09912,
 	AK09916,
+	AK09918,
 };
 
 enum ak_ctrl_reg_addr {
@@ -371,6 +373,34 @@ static const struct ak_def ak_def_array[] = {
 			AK09912_REG_HXL,
 			AK09912_REG_HYL,
 			AK09912_REG_HZL},
+	},
+	[AK09918] = {
+		/* ak09918 is register compatible with ak09912 this is for avoid
+		 * unknown id messages.
+		 */
+		.type = AK09918,
+		.raw_to_gauss = ak09912_raw_to_gauss,
+		.range = 32752,
+		.ctrl_regs = {
+			AK09912_REG_ST1,
+			AK09912_REG_ST2,
+			AK09912_REG_CNTL2,
+			AK09912_REG_ASAX,
+			AK09912_MAX_REGS},
+		.ctrl_masks = {
+			AK09912_REG_ST1_DRDY_MASK,
+			AK09912_REG_ST2_HOFL_MASK,
+			0,
+			AK09912_REG_CNTL2_MODE_MASK},
+		.ctrl_modes = {
+			AK09912_REG_CNTL_MODE_POWER_DOWN,
+			AK09912_REG_CNTL_MODE_ONCE,
+			AK09912_REG_CNTL_MODE_SELF_TEST,
+			AK09912_REG_CNTL_MODE_FUSE_ROM},
+		.data_regs = {
+			AK09912_REG_HXL,
+			AK09912_REG_HYL,
+			AK09912_REG_HZL},
 	}
 };
 
@@ -452,6 +482,7 @@ static int ak8975_who_i_am(struct i2c_client *client,
 	/*
 	 * Signature for each device:
 	 * Device   |  WIA1      |  WIA2
+	 * AK09918  |  DEVICE_ID_|  AK09918_DEVICE_ID
 	 * AK09916  |  DEVICE_ID_|  AK09916_DEVICE_ID
 	 * AK09912  |  DEVICE_ID |  AK09912_DEVICE_ID
 	 * AK09911  |  DEVICE_ID |  AK09911_DEVICE_ID
@@ -484,6 +515,10 @@ static int ak8975_who_i_am(struct i2c_client *client,
 		if (wia_val[1] == AK09916_DEVICE_ID)
 			return 0;
 		break;
+	case AK09918:
+		if (wia_val[1] == AK09918_DEVICE_ID)
+			return 0;
+		break;
 	}
 
 	dev_info(&client->dev, "Device ID %x is unknown.\n", wia_val[1]);
@@ -1071,6 +1106,7 @@ static const struct i2c_device_id ak8975_id[] = {
 	{"ak09911", (kernel_ulong_t)&ak_def_array[AK09911] },
 	{"ak09912", (kernel_ulong_t)&ak_def_array[AK09912] },
 	{"ak09916", (kernel_ulong_t)&ak_def_array[AK09916] },
+	{"ak09918", (kernel_ulong_t)&ak_def_array[AK09918] },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ak8975_id);
@@ -1085,6 +1121,7 @@ static const struct of_device_id ak8975_of_match[] = {
 	{ .compatible = "asahi-kasei,ak09912", .data = &ak_def_array[AK09912] },
 	{ .compatible = "ak09912", .data = &ak_def_array[AK09912] },
 	{ .compatible = "asahi-kasei,ak09916", .data = &ak_def_array[AK09916] },
+	{ .compatible = "asahi-kasei,ak09918", .data = &ak_def_array[AK09918] },
 	{}
 };
 MODULE_DEVICE_TABLE(of, ak8975_of_match);