2023-10-23 16:27:29

by Andrew Davis

Subject: [PATCH v4] 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(-)

diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
index fd1d121a584ba..07c99588ff999 100644
--- a/drivers/mux/mmio.c
+++ b/drivers/mux/mmio.c
@@ -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");
--
2.39.2

2023-10-25 05:45:52

by Peter Rosin

Subject: Re: [PATCH v4] mux: mmio: use reg property when parent device is not a syscon

Hi!

2023-10-23 at 18:26, Andrew Davis wrote:
> 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(-)
>
> diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
> index fd1d121a584ba..07c99588ff999 100644
> --- a/drivers/mux/mmio.c
> +++ b/drivers/mux/mmio.c
> @@ -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);

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);
}

> + }
> 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

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