spi: spidev: Warn loudly if instantiated from DT as "spidev"
Since spidev is a detail of how Linux controls a device rather than a
description of the hardware in the system we should never have a node
described as "spidev" in DT, any SPI device could be a spidev so this
is just not a useful description.
In order to help prevent users from writing such device trees generate a
warning if spidev is instantiated as a DT node without an ID in the match
table.
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 23ad978..92c909e 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -703,6 +703,14 @@
static struct class *spidev_class;
+#ifdef CONFIG_OF
+static const struct of_device_id spidev_dt_ids[] = {
+ { .compatible = "rohm,dh2228fv" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, spidev_dt_ids);
+#endif
+
/*-------------------------------------------------------------------------*/
static int spidev_probe(struct spi_device *spi)
@@ -711,6 +719,17 @@
int status;
unsigned long minor;
+ /*
+ * spidev should never be referenced in DT without a specific
+ * compatbile string, it is a Linux implementation thing
+ * rather than a description of the hardware.
+ */
+ if (spi->dev.of_node && !of_match_device(spidev_dt_ids, &spi->dev)) {
+ dev_err(&spi->dev, "buggy DT: spidev listed directly in DT\n");
+ WARN_ON(spi->dev.of_node &&
+ !of_match_device(spidev_dt_ids, &spi->dev));
+ }
+
/* Allocate driver data */
spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
if (!spidev)
@@ -777,13 +796,6 @@
return 0;
}
-static const struct of_device_id spidev_dt_ids[] = {
- { .compatible = "rohm,dh2228fv" },
- {},
-};
-
-MODULE_DEVICE_TABLE(of, spidev_dt_ids);
-
static struct spi_driver spidev_spi_driver = {
.driver = {
.name = "spidev",