[PATCH] spidev: Introduce "linux,spidev-name" property for device tree of spidev.

egyszeregy
2024-05-19T18:17:57Z

From: Benjamin Szőke <egyszeregy@freemail.hu>

Optionally, spidev may have a "linux,spidev-name" property.
This is a string which is defining a custom suffix name for spi device in
/dev/spidev-<name> format. It helps to improve software portability between
various SoCs and reduce complexities of hardware related codes in SWs.

Signed-off-by: Benjamin Szőke <egyszeregy@freemail.hu>
---
drivers/spi/spidev.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 95fb5f1c91c1..e0071522fc6d 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -767,6 +767,8 @@ MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids);

static int spidev_probe(struct spi_device *spi)
{
+ int ret;
+ const char *name;
int (*match)(struct device *dev);
struct spidev_data *spidev;
int status;
@@ -800,9 +802,20 @@ static int spidev_probe(struct spi_device *spi)
struct device *dev;

spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
- dev = device_create(&spidev_class, &spi->dev, spidev->devt,
- spidev, "spidev%d.%d",
- spi->controller->bus_num, spi_get_chipselect(spi, 0));
+
+ /*
+ * If "linux,spidev-name" is specified in device tree, use /dev/spidev-<name>
+ * in Linux userspace, otherwise use /dev/spidev<bus_num>.<cs_num>.
+ */
+ ret = device_property_read_string(&spi->dev, "linux,spidev-name", &name);
+ if (ret < 0)
+ dev = device_create(spidev_class, &spi->dev, spidev->devt,
+ spidev, "spidev%d.%d",
+ spi->controller->bus_num, spi_get_chipselect(spi, 0));
+ else
+ dev = device_create(spidev_class, &spi->dev, spidev->devt,
+ spidev, "spidev-%s", name);
+
status = PTR_ERR_OR_ZERO(dev);
} else {
dev_dbg(&spi->dev, "no minor number available!\n");
--
2.39.3