[PATCH v4 3/7] dm: core: Support multiple drivers with same compatibles

[Markus Schneider-Pargmann (TI.com)]

Currently once a driver matched the compatible string of a device, other
drivers are ignored. If the first matching driver returns -ENODEV, no
other possibly matching drivers are iterated with that compatible of the
device. Instead the next compatible in the list of compatibles is
selected, assuming only one driver matches one compatible at a time.

To be able to use the bind function to return -ENODEV and continue
matching other drivers with the same compatible, move the for loop a bit
to continue the for loop after -ENODEV was returned. The loop had to be
adjusted a bit to still support the 'drv' argument properly. Some
simplifications were done as well.

The modification will only add additional loop iterations if -ENODEV is
returned. Otherwise the exit and continue conditions for the loop stay
the same and do not cause any additional iterations and should not
impact performance.

This is required for ti-musb-host and ti-musb-peripheral which both
match on the same device but differ based on the dr_mode DT property.
Depending on this property, the driver is either UCLASS_USB or
UCLASS_USB_GADGET_GENERIC. By checking the DT property in the bind
function and returning -ENODEV the other driver can probe instead.

Reviewed-by: Simon Glass <simon.glass at canonical.com>
Acked-by: Dinesh Maniyam <dinesh.maniyam at altera.com>
Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp at baylibre.com>
---
 drivers/core/lists.c | 65 ++++++++++++++++++++++++++--------------------------
 1 file changed, 33 insertions(+), 32 deletions(-)

diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 9d1ca38212ee7f53b8894f964f096611c8ec20a5..813c3de52b23d78528686a7a8d9ecbe8cab62efd 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -235,50 +235,51 @@ int lists_bind_fdt(struct udevice *parent, ofnode node, struct udevice **devp,
 		log_debug("   - attempt to match compatible string '%s'\n",
 			  compat);
 
-		id = NULL;
 		for (entry = driver; entry != driver + n_ents; entry++) {
+			/* Search for drivers with matching drv or existing of_match */
 			if (drv) {
 				if (drv != entry)
 					continue;
-				if (!entry->of_match)
-					break;
+			} else if (!entry->of_match) {
+				continue;
 			}
-			ret = driver_check_compatible(entry->of_match, &id,
-						      compat);
-			if (!ret)
-				break;
-		}
-		if (entry == driver + n_ents)
-			continue;
 
-		if (pre_reloc_only) {
-			if (!ofnode_pre_reloc(node) &&
-			    !(entry->flags & DM_FLAG_PRE_RELOC)) {
-				log_debug("Skipping device pre-relocation\n");
-				return 0;
+			id = NULL;
+			if (entry->of_match) {
+				ret = driver_check_compatible(entry->of_match, &id,
+							      compat);
+				if (ret)
+					continue;
+				log_debug("   - found match at driver '%s' for '%s'\n",
+					  entry->name, id->compatible);
+			}
+
+			if (pre_reloc_only) {
+				if (!ofnode_pre_reloc(node) &&
+				    !(entry->flags & DM_FLAG_PRE_RELOC)) {
+					log_debug("Skipping device pre-relocation\n");
+					return 0;
+				}
+			}
+
+			ret = device_bind_with_driver_data(parent, entry, name,
+							   id ? id->data : 0, node,
+							   &dev);
+			if (!drv && ret == -ENODEV) {
+				log_debug("Driver '%s' refuses to bind\n", entry->name);
+				continue;
+			}
+			if (ret) {
+				dm_warn("Error binding driver '%s': %d\n", entry->name,
+					ret);
+				return log_msg_ret("bind", ret);
 			}
-		}
 
-		if (entry->of_match)
-			log_debug("   - found match at driver '%s' for '%s'\n",
-				  entry->name, id->compatible);
-		ret = device_bind_with_driver_data(parent, entry, name,
-						   id ? id->data : 0, node,
-						   &dev);
-		if (ret == -ENODEV) {
-			log_debug("Driver '%s' refuses to bind\n", entry->name);
-			continue;
-		}
-		if (ret) {
-			dm_warn("Error binding driver '%s': %d\n", entry->name,
-				ret);
-			return log_msg_ret("bind", ret);
-		} else {
 			if (devp)
 				*devp = dev;
+
 			return 0;
 		}
-		break;
 	}
 
 	if (ret != -ENODEV)

-- 
2.51.0