[PATCH v2] iio: adc: ti-adc081c: Partial revert of removal of ACPI IDs

[Jonathan Cameron <jic23@kernel.org>]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Unfortuanately a non standards compliant ACPI ID is known to be
in the wild on some AAEON boards.

Partly revert the removal of these IDs so that ADC081C will again
work + add a comment to that affect for future reference.

Whilst here use generic firmware properties rather than the ACPI
specific handling previously found in this driver.

Reported-by: Kunyang Fan <Kunyang_Fan@aaeon.com.tw>
Fixes: c458b7ca3fd0 ("iio:adc:ti-adc081c: Drop ACPI ids that seem very unlikely to be official.")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
---

Looking ideally for a tested-by for this from Kunyang Fan.

v2: Use generic firmware properties as Andy Shevchenko rightly suggested.
I took it a bit further than strictly necessary as I don't like putting
enums in the driver_data only to use them to index a table when we could
just use the pointers directly.

Note this driver does have device tree binding documentation
but that's a job for another day.  Or maybe later today if I get really
bored this evening :)

 drivers/iio/adc/ti-adc081c.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c
index 16fc608db36a..bd48b073e720 100644
--- a/drivers/iio/adc/ti-adc081c.c
+++ b/drivers/iio/adc/ti-adc081c.c
@@ -19,6 +19,7 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
+#include <linux/property.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
@@ -156,13 +157,16 @@ static int adc081c_probe(struct i2c_client *client,
 {
 	struct iio_dev *iio;
 	struct adc081c *adc;
-	struct adcxx1c_model *model;
+	const struct adcxx1c_model *model;
 	int err;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 		return -EOPNOTSUPP;
 
-	model = &adcxx1c_models[id->driver_data];
+	if (dev_fwnode(&client->dev))
+		model = device_get_match_data(&client->dev);
+	else
+		model = &adcxx1c_models[id->driver_data];
 
 	iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
 	if (!iio)
@@ -210,10 +214,17 @@ static const struct i2c_device_id adc081c_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, adc081c_id);
 
+static const struct acpi_device_id adc081c_acpi_match[] = {
+	/* Used on some AAEON boards */
+	{ "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
+
 static const struct of_device_id adc081c_of_match[] = {
-	{ .compatible = "ti,adc081c" },
-	{ .compatible = "ti,adc101c" },
-	{ .compatible = "ti,adc121c" },
+	{ .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
+	{ .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
+	{ .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, adc081c_of_match);
@@ -222,6 +233,7 @@ static struct i2c_driver adc081c_driver = {
 	.driver = {
 		.name = "adc081c",
 		.of_match_table = adc081c_of_match,
+		.acpi_match_table = adc081c_acpi_match,
 	},
 	.probe = adc081c_probe,
 	.id_table = adc081c_id,
-- 
2.34.1