scsi/cxlflash: Deprecate driver

We intend to remove the cxlflash driver in an upcoming release. It is
already marked as Obsolete in MAINTAINERS.

The cxlflash driver has received minimal maintenance for some time, and
the CAPI Flash hardware that uses it is no longer commercially available.

Add a warning message on probe and change Kconfig to label the driver as
deprecated and not build the driver by default.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241210054055.144813-3-ajd@linux.ibm.com

Author: ajdlinux

drivers/scsi/cxlflash/Kconfig

@@ -4,10 +4,12 @@
 #
 
 config CXLFLASH
-	tristate "Support for IBM CAPI Flash"
+	tristate "Support for IBM CAPI Flash (DEPRECATED)"
 	depends on PCI && SCSI && (CXL || OCXL) && EEH
 	select IRQ_POLL
-	default m
 	help
+	  The cxlflash driver is deprecated and will be removed in a future
+	  kernel release.
+
 	  Allows CAPI Accelerated IO to Flash
 	  If unsure, say N.

drivers/scsi/cxlflash/main.c

@@ -3651,6 +3651,8 @@ static int cxlflash_probe(struct pci_dev *pdev,
 	int rc = 0;
 	int k;
 
+	dev_err_once(&pdev->dev, "DEPRECATION: cxlflash is deprecated and will be removed in a future kernel release\n");
+
 	dev_dbg(&pdev->dev, "%s: Found CXLFLASH with IRQ: %d\n",
 		__func__, pdev->irq);