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

PATCH Superseded Andrew Davis 2 participants 2 messages Oct 23, 2023 – Oct 25, 2023 Multiplexer

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Andrew Davis

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2023-10-23 16:27 UTC #0 lore raw

PATCH v4 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]>

---

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 | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

drivers/mux/mmio.c +8 -5

index fd1d121a584ba..07c99588ff999 100644
@@ -44,14 +44,17 @@ 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);
+	} else {
+		regmap = device_node_to_regmap(np);
+		/* Fallback to checking the parent node on any error other than probe defer */
+		if (IS_ERR(regmap) && regmap != ERR_PTR(-EPROBE_DEFER))
+			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;
+		return dev_err_probe(dev, ret, "failed to get regmap\n");
 	}
 
 	ret = of_property_count_u32_elems(np, "mux-reg-masks");

Signature · 1 line

2.39.2

Peter Rosin

2023-10-25 05:45 UTC #1 lore raw

Hi!

Quoted 35 lines · Andrew Davis

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]>
---
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 | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)
drivers/mux/mmio.c +0 -0
index fd1d121a584ba..07c99588ff999 100644
@@ -44,14 +44,17 @@ static int mux_mmio_probe(struct platform_device *pdev)
 	int ret;
 	int i;
 

drivers/mux/mmio.c static int mux_mmio_probe(struct platform_device *pdev) · line 53

Quoted 10 lines

drivers/mux/mmio.c +6 -3

-	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);
+	} else {
+		regmap = device_node_to_regmap(np);
+		/* Fallback to checking the parent node on any error other than probe defer */
+		if (IS_ERR(regmap) && regmap != ERR_PTR(-EPROBE_DEFER))
+			regmap = dev_get_regmap(dev->parent, NULL) ?: ERR_PTR(-ENODEV);

I'm not too fond of overly long lines, and the coding style document agrees with me. Also, please end comments with a period.

		/* 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);
		}

drivers/mux/mmio.c static int mux_mmio_probe(struct platform_device *pdev) · line 58

Quoted 7 lines

drivers/mux/mmio.c +2 -2

+	}
 	if (IS_ERR(regmap)) {
 		ret = PTR_ERR(regmap);
-		dev_err(dev, "failed to get regmap: %d\n", ret);
-		return ret;
+		return dev_err_probe(dev, ret, "failed to get regmap\n");
 	}

Now that you use dev_err_probe(), please drop the pointless ret assignment:

if (IS_ERR(regmap))

		return dev_err_probe(dev, PTR_ERR(regmap),
				     "failed to get regmap\n");

With those changes, you can add "Acked-by: Peter Rosin <[email protected]>", so that Greg can pick it up.

Cheers,
Peter

Quoted 2 lines

drivers/mux/mmio.c +0 -0

 	ret = of_property_count_u32_elems(np, "mux-reg-masks");