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mux: mmio: use reg property when parent device is not a syscon

PATCH New Andrew Davis 1 participant 1 message Jan 4, 2024 Multiplexer

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Andrew Davis

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PATCH v6 1/1 mux: mmio: use reg property when parent device is not a syscon

The DT binding for the reg-mux compatible states it can be used when the "parent device of mux controller is not syscon device". It also allows for a reg property. When the reg property is provided, use that to identify the address space for this mux. If not provided fallback to using the parent device as a regmap provider.

While here use dev_err_probe() in the error path to prevent printing a message on probe defer which now can happen in extra ways.

Signed-off-by Andrew Davis <[email protected]>
Reviewed-by Nishanth Menon <[email protected]>
Acked-by Peter Rosin <[email protected]>

---

Changes from v5:
- Rebased on next-20240104

Changes from v4:
- Shorten comment and code lines
- Remove extra ret assignment

Changes from v3:
- Check for probe defer

Changes from v2:
- Rebased on v6.6-rc1

Changes from v1:
- Flip logic as suggested in v1[0]

[0] https://lore.kernel.org/lkml/[email protected]/T/

 drivers/mux/mmio.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)
drivers/mux/mmio.c +12 -7
index fd1d121a584ba..30a952c34365f 100644
@@ -44,15 +44,20 @@ static int mux_mmio_probe(struct platform_device *pdev)
 	int ret;
 	int i;
 
-	if (of_device_is_compatible(np, "mmio-mux"))
+	if (of_device_is_compatible(np, "mmio-mux")) {
 		regmap = syscon_node_to_regmap(np->parent);
-	else
-		regmap = dev_get_regmap(dev->parent, NULL) ?: ERR_PTR(-ENODEV);
-	if (IS_ERR(regmap)) {
-		ret = PTR_ERR(regmap);
-		dev_err(dev, "failed to get regmap: %d\n", ret);
-		return ret;
+	} else {
+		regmap = device_node_to_regmap(np);
+		/* Fallback to checking the parent node on "real" errors. */
+		if (IS_ERR(regmap) && regmap != ERR_PTR(-EPROBE_DEFER)) {
+			regmap = dev_get_regmap(dev->parent, NULL);
+			if (!regmap)
+				regmap = ERR_PTR(-ENODEV);
+		}
 	}
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "failed to get regmap\n");
 
 	ret = of_property_count_u32_elems(np, "mux-reg-masks");
 	if (ret == 0 || ret % 2)
Signature · 1 line
2.39.2