diff mbox series

fsi: Add aliased device numbering

Message ID 20230126223850.901302-1-eajames@linux.ibm.com
State New
Headers show
Series fsi: Add aliased device numbering | expand

Commit Message

Eddie James Jan. 26, 2023, 10:38 p.m. UTC 
The I2C and SPI subsystems can use an aliased name to number the device.
Add similar support to the FSI subsystem for any device type.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c    | 31 +++++++++++++++++++++++++++++++
 drivers/fsi/fsi-sbefifo.c |  5 ++---
 drivers/fsi/fsi-scom.c    |  3 ++-
 include/linux/fsi.h       |  1 +
 4 files changed, 36 insertions(+), 4 deletions(-)

Comments

Jeremy Kerr Jan. 27, 2023, 1:03 a.m. UTC | #1 
Hi Eddie,

> The I2C and SPI subsystems can use an aliased name to number the
> device. Add similar support to the FSI subsystem for any device type.

Sounds good!

However, the majority of this patch seems to be the change to a (const)
enum value, which you then convert to a string to generate the
non-number component of the device name.

Does:

       dev_set_name(&scom->dev, "%s%d", fsi_get_dev_type_name(fsi_dev_scom), didx);

have much of a benefit over:

       dev_set_name(&scom->dev, "scom%d", didx);

?

Cheers,


Jeremy
Eddie James Jan. 27, 2023, 2:40 p.m. UTC | #2 
On 1/26/23 19:03, Jeremy Kerr wrote:
> Hi Eddie,
>
>> The I2C and SPI subsystems can use an aliased name to number the
>> device. Add similar support to the FSI subsystem for any device type.
> Sounds good!
>
> However, the majority of this patch seems to be the change to a (const)
> enum value, which you then convert to a string to generate the
> non-number component of the device name.
>
> Does:
>
>         dev_set_name(&scom->dev, "%s%d", fsi_get_dev_type_name(fsi_dev_scom), didx);
>
> have much of a benefit over:
>
>         dev_set_name(&scom->dev, "scom%d", didx);
>
> ?


Hi Jeremy,

I agree, it's not a benefit but my objective here is to make sure the 
device name is definitely the same as what the alias lookup is looking 
for. Perhaps it doesn't matter so much, and I can drop that part of the 
patch...

Thanks for looking!

Eddie


>
> Cheers,
>
>
> Jeremy
diff mbox series

Patch

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 694e80c06665..c3c139c31341 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -971,9 +971,40 @@  static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
 	return 0;
 }
 
+static const char *const fsi_dev_type_names[] = {
+	"cfam",
+	"sbefifo",
+	"scom",
+	"occ",
+};
+
+const char *fsi_get_dev_type_name(enum fsi_dev_type type)
+{
+	return fsi_dev_type_names[type];
+}
+EXPORT_SYMBOL_GPL(fsi_get_dev_type_name);
+
 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
 		      dev_t *out_dev, int *out_index)
 {
+	if (fdev->dev.of_node) {
+		int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);
+
+		if (aid >= 0) {
+			int id = (aid << 4) | type;
+
+			id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
+			if (id >= 0) {
+				*out_index = aid;
+				*out_dev = fsi_base_dev + id;
+				return 0;
+			}
+
+			if (id != -ENOSPC)
+				return id;
+		}
+	}
+
 	return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
 }
 EXPORT_SYMBOL_GPL(fsi_get_new_minor);
diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c
index 9912b7a6a4b9..c79396ba982e 100644
--- a/drivers/fsi/fsi-sbefifo.c
+++ b/drivers/fsi/fsi-sbefifo.c
@@ -39,7 +39,6 @@ 
  * the self boot engine on POWER processors.
  */
 
-#define DEVICE_NAME		"sbefifo"
 #define FSI_ENGID_SBE		0x22
 
 /*
@@ -1046,7 +1045,7 @@  static int sbefifo_probe(struct device *dev)
 	if (rc)
 		goto err;
 
-	dev_set_name(&sbefifo->dev, "sbefifo%d", didx);
+	dev_set_name(&sbefifo->dev, "%s%d", fsi_get_dev_type_name(fsi_dev_sbefifo), didx);
 	cdev_init(&sbefifo->cdev, &sbefifo_fops);
 	rc = cdev_device_add(&sbefifo->cdev, &sbefifo->dev);
 	if (rc) {
@@ -1117,7 +1116,7 @@  static const struct fsi_device_id sbefifo_ids[] = {
 static struct fsi_driver sbefifo_drv = {
 	.id_table = sbefifo_ids,
 	.drv = {
-		.name = DEVICE_NAME,
+		.name = "sbefifo",
 		.bus = &fsi_bus_type,
 		.probe = sbefifo_probe,
 		.remove = sbefifo_remove,
diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c
index bcb756dc9866..ee2c70906d06 100644
--- a/drivers/fsi/fsi-scom.c
+++ b/drivers/fsi/fsi-scom.c
@@ -556,7 +556,8 @@  static int scom_probe(struct device *dev)
 	if (rc)
 		goto err;
 
-	dev_set_name(&scom->dev, "scom%d", didx);
+	dev_set_name(&scom->dev, "%s%d", fsi_get_dev_type_name(fsi_dev_scom),
+		     didx);
 	cdev_init(&scom->cdev, &scom_fops);
 	rc = cdev_device_add(&scom->cdev, &scom->dev);
 	if (rc) {
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index 3df8c54868df..a6c6c57e146f 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -78,6 +78,7 @@  enum fsi_dev_type {
 	fsi_dev_occ
 };
 
+const char *fsi_get_dev_type_name(enum fsi_dev_type type);
 extern int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
 			     dev_t *out_dev, int *out_index);
 extern void fsi_free_minor(dev_t dev);