iio:accel:da280: Linx 820 Windows tablet has a da280 mapped via ACPI

This adds an ACPI table to the driver and the ACPI ID of the sensor
on the tablet.
Signed-off-by: Luke Ross <luke@lukeross.name>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/da280.c

@@ -11,6 +11,7 @@
 
 #include <linux/module.h>
 #include <linux/i2c.h>
+#include <linux/acpi.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/byteorder/generic.h>
@@ -25,7 +26,7 @@
 #define DA280_MODE_ENABLE		0x1e
 #define DA280_MODE_DISABLE		0x9e
 
-enum { da226, da280 };
+enum da280_chipset { da226, da280 };
 
 /*
  * a value of + or -4096 corresponds to + or - 1G
@@ -91,12 +92,24 @@ static const struct iio_info da280_info = {
 	.read_raw	= da280_read_raw,
 };
 
+static enum da280_chipset da280_match_acpi_device(struct device *dev)
+{
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -EINVAL;
+
+	return (enum da280_chipset) id->driver_data;
+}
+
 static int da280_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret;
 	struct iio_dev *indio_dev;
 	struct da280_data *data;
+	enum da280_chipset chip;
 
 	ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
 	if (ret != DA280_CHIP_ID)
@@ -114,7 +127,14 @@ static int da280_probe(struct i2c_client *client,
 	indio_dev->info = &da280_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = da280_channels;
-	if (id->driver_data == da226) {
+
+	if (ACPI_HANDLE(&client->dev)) {
+		chip = da280_match_acpi_device(&client->dev);
+	} else {
+		chip = id->driver_data;
+	}
+
+	if (chip == da226) {
 		indio_dev->name = "da226";
 		indio_dev->num_channels = 2;
 	} else {
@@ -158,6 +178,12 @@ static int da280_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
 
+static const struct acpi_device_id da280_acpi_match[] = {
+	{"MIRAACC", da280},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
+
 static const struct i2c_device_id da280_i2c_id[] = {
 	{ "da226", da226 },
 	{ "da280", da280 },
@@ -168,6 +194,7 @@ MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
 static struct i2c_driver da280_driver = {
 	.driver = {
 		.name = "da280",
+		.acpi_match_table = ACPI_PTR(da280_acpi_match),
 		.pm = &da280_pm_ops,
 	},
 	.probe		= da280_probe,