[PATCH v4 1/4] dm: core: Bind another driver with the same compatible string

* [PATCH v4 1/4] dm: core: Bind another driver with the same compatible string
@ 2021-10-15 13:17 Michal Simek
  2021-10-15 13:17 ` [PATCH v4 2/4] timer: cadence: Add bind function to driver Michal Simek
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Michal Simek @ 2021-10-15 13:17 UTC (permalink / raw)
  To: u-boot, git, Sean Anderson, Simon Glass

When one IP can have multiple configurations (like timer and PWM) covered
by multiple drivers. Because it is the same IP it should also have the same
compatible string.
Current code look for the first driver which matches compatible string and
call bind function. If this is not the right driver which is express by
returning -ENODEV ("Driver XYZ refuses to bind") there is no reason not to
continue over compatible list to try to find out different driver with the
same compatible string which match it.

When the first compatible string is found core looks for driver bind()
function. If if assigned driver refuse to bind, core continue in a loop to
check if there is another driver which match compatible string.

This driver is going to be used with cdnc,ttc driver which has driver as
timer and also can be used as PWM. The difference is done via #pwm-cells
property in DT.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

Changes in v4:
- Remove goto from code
- Also continue on prereloc case

Changes in v3:
- New patch in series

When this is acked I will spent my time on writing test for it.

---
 drivers/core/lists.c | 84 +++++++++++++++++++++++++++-----------------
 1 file changed, 52 insertions(+), 32 deletions(-)

diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 5d4f2ea0e3ad..8b655db68edb 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -221,45 +221,65 @@ int lists_bind_fdt(struct udevice *parent, ofnode node, struct udevice **devp,
 		compat = compat_list + i;
 		log_debug("   - attempt to match compatible string '%s'\n",
 			  compat);
-
-		for (entry = driver; entry != driver + n_ents; entry++) {
-			ret = driver_check_compatible(entry->of_match, &id,
-						      compat);
-			if ((drv) && (drv == entry))
-				break;
-			if (!ret)
+		entry = driver;
+
+		while (1) {
+			for (; entry != driver + n_ents; entry++) {
+				ret = driver_check_compatible(entry->of_match,
+							      &id, compat);
+				if (drv && drv == entry)
+					break;
+				if (!ret)
+					break;
+			}
+			/*
+			 * Reach the last entry - time to look at next
+			 * compatible string.
+			 */
+			if (entry == driver + n_ents)
 				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;
+
+			if (pre_reloc_only) {
+				if (!ofnode_pre_reloc(node) &&
+				    !(entry->flags & DM_FLAG_PRE_RELOC)) {
+					log_debug("Skipping device pre-relocation\n");
+					entry++;
+					continue;
+				}
 			}
-		}
 
-		log_debug("   - found match at '%s': '%s' matches '%s'\n",
-			  entry->name, entry->of_match->compatible,
-			  id->compatible);
-		ret = device_bind_with_driver_data(parent, entry, name,
-						   id->data, 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 {
+			log_debug("   - found match at '%s': '%s' matches '%s'\n",
+				  entry->name, entry->of_match->compatible,
+				  id->compatible);
+			ret = device_bind_with_driver_data(parent, entry, name,
+							   id->data, node,
+							   &dev);
+			/*
+			 * Driver found but didn't bind properly try another one
+			 */
+			if (ret == -ENODEV) {
+				log_debug("Driver '%s' refuses to bind\n",
+					  entry->name);
+				entry++;
+				continue;
+			}
+
+			/* Error in binding driver */
+			if (ret) {
+				dm_warn("Error binding driver '%s': %d\n",
+					entry->name, ret);
+				return log_msg_ret("bind", ret);
+			}
+
+			/* Properly binded driver */
 			found = true;
 			if (devp)
 				*devp = dev;
+			break;
 		}
-		break;
+
+		if (found)
+			break;
 	}
 
 	if (!found && !result && ret != -ENODEV)
-- 
2.33.1


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