[PATCH v2 1/2] iio: dac: ad5755: make use of of_device_id table

[Krzysztof Kozlowski]

Populate the of_device_id table with match data, reference it in the
spi_driver struct and use spi_get_device_match_data() to perform the
type matching to fix warning:

  ad5755.c:866:34: error: unused variable 'ad5755_of_match' [-Werror,-Wunused-const-variable]

This is also preferred way of matching device variants, then relying on
fallback via spi_device_id.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

---

Rework according to comments.

An old v1:
https://lore.kernel.org/all/20230810111933.205619-1-krzysztof.kozlowski@xxxxxxxxxx/
---
 drivers/iio/dac/ad5755.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
index 404865e35460..877c1125d892 100644
--- a/drivers/iio/dac/ad5755.c
+++ b/drivers/iio/dac/ad5755.c
@@ -809,7 +809,7 @@ static struct ad5755_platform_data *ad5755_parse_fw(struct device *dev)
 
 static int ad5755_probe(struct spi_device *spi)
 {
-	enum ad5755_type type = spi_get_device_id(spi)->driver_data;
+	enum ad5755_type type = (kernel_ulong_t)spi_get_device_match_data(spi);
 	const struct ad5755_platform_data *pdata;
 	struct iio_dev *indio_dev;
 	struct ad5755_state *st;
@@ -864,11 +864,11 @@ static const struct spi_device_id ad5755_id[] = {
 MODULE_DEVICE_TABLE(spi, ad5755_id);
 
 static const struct of_device_id ad5755_of_match[] = {
-	{ .compatible = "adi,ad5755" },
-	{ .compatible = "adi,ad5755-1" },
-	{ .compatible = "adi,ad5757" },
-	{ .compatible = "adi,ad5735" },
-	{ .compatible = "adi,ad5737" },
+	{ .compatible = "adi,ad5755", (void *)ID_AD5755 },
+	{ .compatible = "adi,ad5755-1", (void *)ID_AD5755 },
+	{ .compatible = "adi,ad5757", (void *)ID_AD5757 },
+	{ .compatible = "adi,ad5735", (void *)ID_AD5735 },
+	{ .compatible = "adi,ad5737", (void *)ID_AD5737 },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ad5755_of_match);
@@ -876,6 +876,7 @@ MODULE_DEVICE_TABLE(of, ad5755_of_match);
 static struct spi_driver ad5755_driver = {
 	.driver = {
 		.name = "ad5755",
+		.of_match_table = ad5755_of_match,
 	},
 	.probe = ad5755_probe,
 	.id_table = ad5755_id,
-- 
2.34.1