* [PATCH v5 1/7] phy: can-transceiver: rename temporary helper function to avoid conflict
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
@ 2026-01-18 10:28 ` Josua Mayer
2026-01-20 9:35 ` Geert Uytterhoeven
2026-01-18 10:28 ` [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state Josua Mayer
` (5 subsequent siblings)
6 siblings, 1 reply; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:28 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Rename the temporary devm_mux_state_get_optional function to avoid
conflict with upcoming implementation in multiplexer subsystem.
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/phy/phy-can-transceiver.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 330356706ad7..81591d247128 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -128,7 +128,7 @@ MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
/* Temporary wrapper until the multiplexer subsystem supports optional muxes */
static inline struct mux_state *
-devm_mux_state_get_optional(struct device *dev, const char *mux_name)
+temp_devm_mux_state_get_optional(struct device *dev, const char *mux_name)
{
if (!of_property_present(dev->of_node, "mux-states"))
return NULL;
@@ -183,7 +183,7 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
priv->num_ch = num_ch;
platform_set_drvdata(pdev, priv);
- mux_state = devm_mux_state_get_optional(dev, NULL);
+ mux_state = temp_devm_mux_state_get_optional(dev, NULL);
if (IS_ERR(mux_state))
return PTR_ERR(mux_state);
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v5 1/7] phy: can-transceiver: rename temporary helper function to avoid conflict
2026-01-18 10:28 ` [PATCH v5 1/7] phy: can-transceiver: rename temporary helper function to avoid conflict Josua Mayer
@ 2026-01-20 9:35 ` Geert Uytterhoeven
0 siblings, 0 replies; 14+ messages in thread
From: Geert Uytterhoeven @ 2026-01-20 9:35 UTC (permalink / raw)
To: Josua Mayer
Cc: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang,
Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc
Hi Josua,
On Sun, 18 Jan 2026 at 11:29, Josua Mayer <josua@solid-run.com> wrote:
> Rename the temporary devm_mux_state_get_optional function to avoid
> conflict with upcoming implementation in multiplexer subsystem.
>
> Acked-by: Vinod Koul <vkoul@kernel.org>
> Signed-off-by: Josua Mayer <josua@solid-run.com>
My
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
on v3 is still valid.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
2026-01-18 10:28 ` [PATCH v5 1/7] phy: can-transceiver: rename temporary helper function to avoid conflict Josua Mayer
@ 2026-01-18 10:28 ` Josua Mayer
2026-01-18 13:28 ` kernel test robot
` (2 more replies)
2026-01-18 10:28 ` [PATCH v5 3/7] mux: add help text for MULTIPLEXER config option Josua Mayer
` (4 subsequent siblings)
6 siblings, 3 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:28 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
In-tree phy-can-transceiver driver has already implemented a local
version of devm_mux_state_get_optional.
The omap-i2c driver gets and selects an optional mux in its probe
function without using any helper.
Add new helper functions covering both aforementioned use-cases:
- mux_control_get_optional:
Get a mux-control if specified in dt, return NULL otherwise.
- devm_mux_state_get_optional:
Get a mux-state if specified in dt, return NULL otherwise.
- devm_mux_state_get_selected:
Get and select a mux-state specified in dt, return error otherwise.
- devm_mux_state_get_optional_selected:
Get and select a mux-state if specified in dt, return error or NULL.
Existing mux_get helper function is changed to take an extra argument
indicating whether the mux is optional.
In this case no error is printed, and NULL returned in case of ENOENT.
Calling code is adapted to handle NULL return case, and to pass optional
argument as required.
To support automatic deselect for _selected helper, a new structure is
created storing an exit pointer similar to clock core which is called on
release.
To facilitate code sharing between optional/mandatory/selected helpers,
a new internal helper function is added to handle quiet (optional) and
verbose (mandatory) errors, as well as storing the correct callback for
devm release: __devm_mux_state_get
Due to this structure devm_mux_state_get_*_selected can no longer print
a useful error message when select fails. Instead callers should print
errors where needed.
Commit e153fdea9db04 ("phy: can-transceiver: Re-instate "mux-states"
property presence check") noted that "mux_get() always prints an error
message in case of an error, including when the property is not present,
confusing the user."
The first error message covers the case that a mux name is not matched
in dt. The second error message is based on of_parse_phandle_with_args
return value.
In optional case no error is printed and NULL is returned.
This ensures that the new helper functions will not confuse the user
either.
With the addition of optional helper functions it became clear that
drivers should compile and link even if CONFIG_MULTIPLEXER was not enabled.
Add stubs for all symbols exported by mux core.
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/mux/core.c | 175 ++++++++++++++++++++++++++++++++++++-------
include/linux/mux/consumer.h | 111 ++++++++++++++++++++++++++-
2 files changed, 253 insertions(+), 33 deletions(-)
diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index a3840fe0995f..df30f96ec076 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -46,6 +46,16 @@ static const struct class mux_class = {
.name = "mux",
};
+/*
+ * struct devm_mux_state_state - Tracks managed resources for mux-state objects.
+ * @mux: Pointer to a mux state.
+ * @exit: An optional callback to execte before free.
+ */
+struct devm_mux_state_state {
+ struct mux_state *mstate;
+ int (*exit)(struct mux_state *mstate);
+};
+
static DEFINE_IDA(mux_ida);
static int __init mux_init(void)
@@ -522,11 +532,12 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
* @mux_name: The name identifying the mux-control.
* @state: Pointer to where the requested state is returned, or NULL when
* the required multiplexer states are handled by other means.
+ * @optional: Whether to return NULL and silence errors when mux doesn't exist.
*
* Return: A pointer to the mux-control, or an ERR_PTR with a negative errno.
*/
static struct mux_control *mux_get(struct device *dev, const char *mux_name,
- unsigned int *state)
+ unsigned int *state, bool optional)
{
struct device_node *np = dev->of_node;
struct of_phandle_args args;
@@ -542,7 +553,9 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name,
else
index = of_property_match_string(np, "mux-control-names",
mux_name);
- if (index < 0) {
+ if (index < 0 && optional) {
+ return NULL;
+ } else if (index < 0) {
dev_err(dev, "mux controller '%s' not found\n",
mux_name);
return ERR_PTR(index);
@@ -558,8 +571,12 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name,
"mux-controls", "#mux-control-cells",
index, &args);
if (ret) {
+ if (optional && ret == -ENOENT)
+ return NULL;
+
dev_err(dev, "%pOF: failed to get mux-%s %s(%i)\n",
- np, state ? "state" : "control", mux_name ?: "", index);
+ np, state ? "state" : "control",
+ mux_name ?: "", index);
return ERR_PTR(ret);
}
@@ -617,10 +634,23 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name,
*/
struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
{
- return mux_get(dev, mux_name, NULL);
+ return mux_get(dev, mux_name, NULL, false);
}
EXPORT_SYMBOL_GPL(mux_control_get);
+/**
+ * mux_control_get_optional() - Get the optional mux-control for a device.
+ * @dev: The device that needs a mux-control.
+ * @mux_name: The name identifying the mux-control.
+ *
+ * Return: A pointer to the mux-control, an ERR_PTR with a negative errno.
+ */
+struct mux_control *mux_control_get_optional(struct device *dev, const char *mux_name)
+{
+ return mux_get(dev, mux_name, NULL, true);
+}
+EXPORT_SYMBOL_GPL(mux_control_get_optional);
+
/**
* mux_control_put() - Put away the mux-control for good.
* @mux: The mux-control to put away.
@@ -657,8 +687,8 @@ struct mux_control *devm_mux_control_get(struct device *dev,
if (!ptr)
return ERR_PTR(-ENOMEM);
- mux = mux_control_get(dev, mux_name);
- if (IS_ERR(mux)) {
+ mux = mux_get(dev, mux_name, NULL, false);
+ if (IS_ERR_OR_NULL(mux)) {
devres_free(ptr);
return mux;
}
@@ -677,7 +707,7 @@ EXPORT_SYMBOL_GPL(devm_mux_control_get);
*
* Return: A pointer to the mux-state, or an ERR_PTR with a negative errno.
*/
-static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
+static struct mux_state *mux_state_get(struct device *dev, const char *mux_name, bool optional)
{
struct mux_state *mstate;
@@ -685,12 +715,10 @@ static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
if (!mstate)
return ERR_PTR(-ENOMEM);
- mstate->mux = mux_get(dev, mux_name, &mstate->state);
- if (IS_ERR(mstate->mux)) {
- int err = PTR_ERR(mstate->mux);
-
+ mstate->mux = mux_get(dev, mux_name, &mstate->state, optional);
+ if (IS_ERR_OR_NULL(mstate->mux)) {
kfree(mstate);
- return ERR_PTR(err);
+ return ERR_CAST(mstate->mux);
}
return mstate;
@@ -710,41 +738,130 @@ static void mux_state_put(struct mux_state *mstate)
static void devm_mux_state_release(struct device *dev, void *res)
{
- struct mux_state *mstate = *(struct mux_state **)res;
+ struct devm_mux_state_state *devm_state = res;
- mux_state_put(mstate);
+ if (devm_state->exit)
+ devm_state->exit(devm_state->mstate);
+
+ mux_state_put(devm_state->mstate);
}
/**
- * devm_mux_state_get() - Get the mux-state for a device, with resource
- * management.
- * @dev: The device that needs a mux-control.
- * @mux_name: The name identifying the mux-control.
+ * __devm_mux_state_get() - Get the optional mux-state for a device,
+ * with resource management.
+ * @dev: The device that needs a mux-state.
+ * @mux_name: The name identifying the mux-state.
+ * @optional: Whether to return NULL and silence errors when mux doesn't exist.
+ * @init: Optional function pointer for mux-state object initialisation.
+ * @exit: Optional function pointer for mux-state object cleanup on release.
*
* Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
*/
-struct mux_state *devm_mux_state_get(struct device *dev,
- const char *mux_name)
+static struct mux_state *__devm_mux_state_get(struct device *dev, const char *mux_name,
+ bool optional,
+ int (*init)(struct mux_state *mstate),
+ int (*exit)(struct mux_state *mstate))
{
- struct mux_state **ptr, *mstate;
+ struct devm_mux_state_state *devm_state;
+ struct mux_state *mstate;
+ int ret;
- ptr = devres_alloc(devm_mux_state_release, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
+ devm_state = devres_alloc(devm_mux_state_release, sizeof(*devm_state), GFP_KERNEL);
+ if (!devm_state)
return ERR_PTR(-ENOMEM);
- mstate = mux_state_get(dev, mux_name);
- if (IS_ERR(mstate)) {
- devres_free(ptr);
- return mstate;
+ mstate = mux_state_get(dev, mux_name, optional);
+ if (IS_ERR_OR_NULL(mstate))
+ goto err_mux_state_get;
+
+ if (init) {
+ ret = init(mstate);
+ if (ret)
+ goto err_mux_state_init;
}
- *ptr = mstate;
- devres_add(dev, ptr);
+ devm_state->mstate = mstate;
+ devm_state->exit = exit;
+ devres_add(dev, devm_state);
return mstate;
+
+err_mux_state_init:
+ mux_state_put(mstate);
+err_mux_state_get:
+ devres_free(devm_state);
+ return ERR_PTR(ret);
+}
+
+/**
+ * devm_mux_state_get() - Get the mux-state for a device, with resource
+ * management.
+ * @dev: The device that needs a mux-control.
+ * @mux_name: The name identifying the mux-control.
+ *
+ * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
+ *
+ * The mux-state will automatically be freed on release.
+ */
+struct mux_state *devm_mux_state_get(struct device *dev, const char *mux_name)
+{
+ return __devm_mux_state_get(dev, mux_name, false, NULL, NULL);
}
EXPORT_SYMBOL_GPL(devm_mux_state_get);
+/**
+ * devm_mux_state_get_optional() - Get the optional mux-state for a device,
+ * with resource management.
+ * @dev: The device that needs a mux-state.
+ * @mux_name: The name identifying the mux-state.
+ *
+ * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
+ *
+ * The mux-state will automatically be freed on release.
+ */
+struct mux_state *devm_mux_state_get_optional(struct device *dev, const char *mux_name)
+{
+ return __devm_mux_state_get(dev, mux_name, true, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(devm_mux_state_get_optional);
+
+/**
+ * devm_mux_state_get_selected() - Get the mux-state for a device, with
+ * resource management.
+ * @dev: The device that needs a mux-state.
+ * @mux_name: The name identifying the mux-state.
+ *
+ * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
+ *
+ * The returned mux-state (if valid) is already selected.
+ *
+ * The mux-state will automatically be deselected and freed on release.
+ */
+struct mux_state *devm_mux_state_get_selected(struct device *dev, const char *mux_name)
+{
+ return __devm_mux_state_get(dev, mux_name, false, mux_state_select, mux_state_deselect);
+}
+EXPORT_SYMBOL_GPL(devm_mux_state_get_selected);
+
+/**
+ * devm_mux_state_get_optional_selected() - Get the optional mux-state for
+ * a device, with resource management.
+ * @dev: The device that needs a mux-state.
+ * @mux_name: The name identifying the mux-state.
+ *
+ * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
+ *
+ * The returned mux-state (if valid) is already selected.
+ *
+ * The mux-state will automatically be deselected and freed on release.
+ */
+struct mux_state *devm_mux_state_get_optional_selected(struct device *dev,
+ const char *mux_name)
+{
+ return __devm_mux_state_get(dev, mux_name, true, mux_state_select, mux_state_deselect);
+}
+EXPORT_SYMBOL_GPL(devm_mux_state_get_optional_selected);
+
/*
* Using subsys_initcall instead of module_init here to try to ensure - for
* the non-modular case - that the subsystem is initialized when mux consumers
diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h
index 2e25c838f831..7d591be26b64 100644
--- a/include/linux/mux/consumer.h
+++ b/include/linux/mux/consumer.h
@@ -16,6 +16,8 @@ struct device;
struct mux_control;
struct mux_state;
+#ifdef CONFIG_MULTIPLEXER
+
unsigned int mux_control_states(struct mux_control *mux);
int __must_check mux_control_select_delay(struct mux_control *mux,
unsigned int state,
@@ -54,11 +56,112 @@ int mux_control_deselect(struct mux_control *mux);
int mux_state_deselect(struct mux_state *mstate);
struct mux_control *mux_control_get(struct device *dev, const char *mux_name);
+struct mux_control *mux_control_get_optional(struct device *dev, const char *mux_name);
void mux_control_put(struct mux_control *mux);
-struct mux_control *devm_mux_control_get(struct device *dev,
- const char *mux_name);
-struct mux_state *devm_mux_state_get(struct device *dev,
- const char *mux_name);
+struct mux_control *devm_mux_control_get(struct device *dev, const char *mux_name);
+struct mux_state *devm_mux_state_get(struct device *dev, const char *mux_name);
+struct mux_state *devm_mux_state_get_optional(struct device *dev, const char *mux_name);
+struct mux_state *devm_mux_state_get_selected(struct device *dev, const char *mux_name);
+struct mux_state *devm_mux_state_get_optional_selected(struct device *dev, const char *mux_name);
+
+#else
+
+static inline unsigned int mux_control_states(struct mux_control *mux)
+{
+ return 0;
+}
+static inline int __must_check mux_control_select_delay(struct mux_control *mux,
+ unsigned int state, unsigned int delay_us)
+{
+ return -EOPNOTSUPP;
+}
+static inline int __must_check mux_state_select_delay(struct mux_state *mstate,
+ unsigned int delay_us)
+{
+ return -EOPNOTSUPP;
+}
+static inline int __must_check mux_control_try_select_delay(struct mux_control *mux,
+ unsigned int state,
+ unsigned int delay_us)
+{
+ return -EOPNOTSUPP;
+}
+static inline int __must_check mux_state_try_select_delay(struct mux_state *mstate,
+ unsigned int delay_us)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int __must_check mux_control_select(struct mux_control *mux,
+ unsigned int state)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int __must_check mux_state_select(struct mux_state *mstate)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int __must_check mux_control_try_select(struct mux_control *mux,
+ unsigned int state)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int __must_check mux_state_try_select(struct mux_state *mstate)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int mux_control_deselect(struct mux_control *mux)
+{
+ return -EOPNOTSUPP;
+}
+static inline int mux_state_deselect(struct mux_state *mstate)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct mux_control *mux_control_get_optional(struct device *dev,
+ const char *mux_name)
+{
+ return NULL;
+}
+static inline void mux_control_put(struct mux_control *mux)
+{
+ return;
+}
+
+static inline struct mux_control *devm_mux_control_get(struct device *dev, const char *mux_name)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct mux_state *devm_mux_state_get(struct device *dev, const char *mux_name)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct mux_state *devm_mux_state_get_optional(struct device *dev,
+ const char *mux_name)
+{
+ return NULL;
+}
+static inline struct mux_state *devm_mux_state_get_selected(struct device *dev,
+ const char *mux_name)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct mux_state *devm_mux_state_get_optional_selected(struct device *dev,
+ const char *mux_name)
+{
+ return NULL;
+}
+
+#endif /* CONFIG_MULTIPLEXER */
#endif /* _LINUX_MUX_CONSUMER_H */
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
2026-01-18 10:28 ` [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state Josua Mayer
@ 2026-01-18 13:28 ` kernel test robot
2026-01-20 9:45 ` Geert Uytterhoeven
2026-01-20 15:57 ` Geert Uytterhoeven
2 siblings, 0 replies; 14+ messages in thread
From: kernel test robot @ 2026-01-18 13:28 UTC (permalink / raw)
To: Josua Mayer, Marc Kleine-Budde, Vincent Mailhol, Vinod Koul,
Neil Armstrong, Peter Rosin, Aaro Koskinen, Andreas Kemnade,
Kevin Hilman, Roger Quadros, Tony Lindgren, Janusz Krzysztofik,
Vignesh R, Andi Shyti, Ulf Hansson, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Geert Uytterhoeven,
Magnus Damm, Wolfram Sang
Cc: oe-kbuild-all, Yazan Shhady, Jon Nettleton, Mikhail Anikin,
linux-can, linux-phy, linux-kernel, linux-omap, linux-i2c,
linux-mmc, devicetree
Hi Josua,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 8f0b4cce4481fb22653697cced8d0d04027cb1e8]
url: https://github.com/intel-lab-lkp/linux/commits/Josua-Mayer/phy-can-transceiver-rename-temporary-helper-function-to-avoid-conflict/20260118-183905
base: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
patch link: https://lore.kernel.org/r/20260118-rz-sdio-mux-v5-2-3c37e8872683%40solid-run.com
patch subject: [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
config: um-randconfig-r071-20260118 (https://download.01.org/0day-ci/archive/20260118/202601182117.l2nFZ5OB-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
smatch version: v0.5.0-8985-g2614ff1a
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260118/202601182117.l2nFZ5OB-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601182117.l2nFZ5OB-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/mux/core.c:774:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
774 | if (IS_ERR_OR_NULL(mstate))
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/mux/core.c:793:17: note: uninitialized use occurs here
793 | return ERR_PTR(ret);
| ^~~
drivers/mux/core.c:774:2: note: remove the 'if' if its condition is always false
774 | if (IS_ERR_OR_NULL(mstate))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
775 | goto err_mux_state_get;
| ~~~~~~~~~~~~~~~~~~~~~~
drivers/mux/core.c:767:9: note: initialize the variable 'ret' to silence this warning
767 | int ret;
| ^
| = 0
1 warning generated.
vim +774 drivers/mux/core.c
748
749 /**
750 * __devm_mux_state_get() - Get the optional mux-state for a device,
751 * with resource management.
752 * @dev: The device that needs a mux-state.
753 * @mux_name: The name identifying the mux-state.
754 * @optional: Whether to return NULL and silence errors when mux doesn't exist.
755 * @init: Optional function pointer for mux-state object initialisation.
756 * @exit: Optional function pointer for mux-state object cleanup on release.
757 *
758 * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno.
759 */
760 static struct mux_state *__devm_mux_state_get(struct device *dev, const char *mux_name,
761 bool optional,
762 int (*init)(struct mux_state *mstate),
763 int (*exit)(struct mux_state *mstate))
764 {
765 struct devm_mux_state_state *devm_state;
766 struct mux_state *mstate;
767 int ret;
768
769 devm_state = devres_alloc(devm_mux_state_release, sizeof(*devm_state), GFP_KERNEL);
770 if (!devm_state)
771 return ERR_PTR(-ENOMEM);
772
773 mstate = mux_state_get(dev, mux_name, optional);
> 774 if (IS_ERR_OR_NULL(mstate))
775 goto err_mux_state_get;
776
777 if (init) {
778 ret = init(mstate);
779 if (ret)
780 goto err_mux_state_init;
781 }
782
783 devm_state->mstate = mstate;
784 devm_state->exit = exit;
785 devres_add(dev, devm_state);
786
787 return mstate;
788
789 err_mux_state_init:
790 mux_state_put(mstate);
791 err_mux_state_get:
792 devres_free(devm_state);
793 return ERR_PTR(ret);
794 }
795
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
2026-01-18 10:28 ` [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state Josua Mayer
2026-01-18 13:28 ` kernel test robot
@ 2026-01-20 9:45 ` Geert Uytterhoeven
2026-01-21 9:00 ` Josua Mayer
2026-01-20 15:57 ` Geert Uytterhoeven
2 siblings, 1 reply; 14+ messages in thread
From: Geert Uytterhoeven @ 2026-01-20 9:45 UTC (permalink / raw)
To: Josua Mayer
Cc: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang,
Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc
Hi Josua,
On Sun, 18 Jan 2026 at 11:29, Josua Mayer <josua@solid-run.com> wrote:
> In-tree phy-can-transceiver driver has already implemented a local
> version of devm_mux_state_get_optional.
>
> The omap-i2c driver gets and selects an optional mux in its probe
> function without using any helper.
>
> Add new helper functions covering both aforementioned use-cases:
>
> - mux_control_get_optional:
> Get a mux-control if specified in dt, return NULL otherwise.
> - devm_mux_state_get_optional:
> Get a mux-state if specified in dt, return NULL otherwise.
> - devm_mux_state_get_selected:
> Get and select a mux-state specified in dt, return error otherwise.
> - devm_mux_state_get_optional_selected:
> Get and select a mux-state if specified in dt, return error or NULL.
>
> Existing mux_get helper function is changed to take an extra argument
> indicating whether the mux is optional.
> In this case no error is printed, and NULL returned in case of ENOENT.
>
> Calling code is adapted to handle NULL return case, and to pass optional
> argument as required.
>
> To support automatic deselect for _selected helper, a new structure is
> created storing an exit pointer similar to clock core which is called on
> release.
>
> To facilitate code sharing between optional/mandatory/selected helpers,
> a new internal helper function is added to handle quiet (optional) and
> verbose (mandatory) errors, as well as storing the correct callback for
> devm release: __devm_mux_state_get
>
> Due to this structure devm_mux_state_get_*_selected can no longer print
> a useful error message when select fails. Instead callers should print
> errors where needed.
>
> Commit e153fdea9db04 ("phy: can-transceiver: Re-instate "mux-states"
> property presence check") noted that "mux_get() always prints an error
> message in case of an error, including when the property is not present,
> confusing the user."
>
> The first error message covers the case that a mux name is not matched
> in dt. The second error message is based on of_parse_phandle_with_args
> return value.
>
> In optional case no error is printed and NULL is returned.
> This ensures that the new helper functions will not confuse the user
> either.
>
> With the addition of optional helper functions it became clear that
> drivers should compile and link even if CONFIG_MULTIPLEXER was not enabled.
> Add stubs for all symbols exported by mux core.
>
> Signed-off-by: Josua Mayer <josua@solid-run.com>
Thanks for your patch!
> --- a/drivers/mux/core.c
> +++ b/drivers/mux/core.c
> @@ -677,7 +707,7 @@ EXPORT_SYMBOL_GPL(devm_mux_control_get);
> *
> * Return: A pointer to the mux-state, or an ERR_PTR with a negative errno.
> */
> -static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
> +static struct mux_state *mux_state_get(struct device *dev, const char *mux_name, bool optional)
> {
> struct mux_state *mstate;
>
> @@ -685,12 +715,10 @@ static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
> if (!mstate)
> return ERR_PTR(-ENOMEM);
>
> - mstate->mux = mux_get(dev, mux_name, &mstate->state);
> - if (IS_ERR(mstate->mux)) {
> - int err = PTR_ERR(mstate->mux);
> -
> + mstate->mux = mux_get(dev, mux_name, &mstate->state, optional);
> + if (IS_ERR_OR_NULL(mstate->mux)) {
> kfree(mstate);
mstate is freed here...
> - return ERR_PTR(err);
> + return ERR_CAST(mstate->mux);
... and dereferenced here, leading to a use after free.
> }
>
> return mstate;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
2026-01-20 9:45 ` Geert Uytterhoeven
@ 2026-01-21 9:00 ` Josua Mayer
0 siblings, 0 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-21 9:00 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang,
Yazan Shhady, Jon Nettleton, Mikhail Anikin,
linux-can@vger.kernel.org, linux-phy@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
linux-i2c@vger.kernel.org, linux-mmc@vger.kernel.org,
devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org
On 20/01/2026 11:45, Geert Uytterhoeven wrote:
> Hi Josua,
>
> On Sun, 18 Jan 2026 at 11:29, Josua Mayer <josua@solid-run.com> wrote:
>> In-tree phy-can-transceiver driver has already implemented a local
>> version of devm_mux_state_get_optional.
>>
>> The omap-i2c driver gets and selects an optional mux in its probe
>> function without using any helper.
>>
>> Add new helper functions covering both aforementioned use-cases:
>>
>> - mux_control_get_optional:
>> Get a mux-control if specified in dt, return NULL otherwise.
>> - devm_mux_state_get_optional:
>> Get a mux-state if specified in dt, return NULL otherwise.
>> - devm_mux_state_get_selected:
>> Get and select a mux-state specified in dt, return error otherwise.
>> - devm_mux_state_get_optional_selected:
>> Get and select a mux-state if specified in dt, return error or NULL.
>>
>> Existing mux_get helper function is changed to take an extra argument
>> indicating whether the mux is optional.
>> In this case no error is printed, and NULL returned in case of ENOENT.
>>
>> Calling code is adapted to handle NULL return case, and to pass optional
>> argument as required.
>>
>> To support automatic deselect for _selected helper, a new structure is
>> created storing an exit pointer similar to clock core which is called on
>> release.
>>
>> To facilitate code sharing between optional/mandatory/selected helpers,
>> a new internal helper function is added to handle quiet (optional) and
>> verbose (mandatory) errors, as well as storing the correct callback for
>> devm release: __devm_mux_state_get
>>
>> Due to this structure devm_mux_state_get_*_selected can no longer print
>> a useful error message when select fails. Instead callers should print
>> errors where needed.
>>
>> Commit e153fdea9db04 ("phy: can-transceiver: Re-instate "mux-states"
>> property presence check") noted that "mux_get() always prints an error
>> message in case of an error, including when the property is not present,
>> confusing the user."
>>
>> The first error message covers the case that a mux name is not matched
>> in dt. The second error message is based on of_parse_phandle_with_args
>> return value.
>>
>> In optional case no error is printed and NULL is returned.
>> This ensures that the new helper functions will not confuse the user
>> either.
>>
>> With the addition of optional helper functions it became clear that
>> drivers should compile and link even if CONFIG_MULTIPLEXER was not enabled.
>> Add stubs for all symbols exported by mux core.
>>
>> Signed-off-by: Josua Mayer <josua@solid-run.com>
> Thanks for your patch!
>
>> --- a/drivers/mux/core.c
>> +++ b/drivers/mux/core.c
>> @@ -677,7 +707,7 @@ EXPORT_SYMBOL_GPL(devm_mux_control_get);
>> *
>> * Return: A pointer to the mux-state, or an ERR_PTR with a negative errno.
>> */
>> -static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
>> +static struct mux_state *mux_state_get(struct device *dev, const char *mux_name, bool optional)
>> {
>> struct mux_state *mstate;
>>
>> @@ -685,12 +715,10 @@ static struct mux_state *mux_state_get(struct device *dev, const char *mux_name)
>> if (!mstate)
>> return ERR_PTR(-ENOMEM);
>>
>> - mstate->mux = mux_get(dev, mux_name, &mstate->state);
>> - if (IS_ERR(mstate->mux)) {
>> - int err = PTR_ERR(mstate->mux);
>> -
>> + mstate->mux = mux_get(dev, mux_name, &mstate->state, optional);
>> + if (IS_ERR_OR_NULL(mstate->mux)) {
>> kfree(mstate);
> mstate is freed here...
>
>> - return ERR_PTR(err);
>> + return ERR_CAST(mstate->mux);
> ... and dereferenced here, leading to a use after free.
Thank you for spotting this, I will resolve it in next version!
(along with what the kernel robot found)
>
>> }
>>
>> return mstate;
> Gr{oetje,eeting}s,
>
> Geert
>
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state
2026-01-18 10:28 ` [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state Josua Mayer
2026-01-18 13:28 ` kernel test robot
2026-01-20 9:45 ` Geert Uytterhoeven
@ 2026-01-20 15:57 ` Geert Uytterhoeven
2 siblings, 0 replies; 14+ messages in thread
From: Geert Uytterhoeven @ 2026-01-20 15:57 UTC (permalink / raw)
To: Josua Mayer
Cc: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang,
Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc
Hi Josua,
On Sun, 18 Jan 2026 at 11:29, Josua Mayer <josua@solid-run.com> wrote:
> In-tree phy-can-transceiver driver has already implemented a local
> version of devm_mux_state_get_optional.
>
> The omap-i2c driver gets and selects an optional mux in its probe
> function without using any helper.
>
> Add new helper functions covering both aforementioned use-cases:
>
> - mux_control_get_optional:
> Get a mux-control if specified in dt, return NULL otherwise.
> - devm_mux_state_get_optional:
> Get a mux-state if specified in dt, return NULL otherwise.
> - devm_mux_state_get_selected:
> Get and select a mux-state specified in dt, return error otherwise.
> - devm_mux_state_get_optional_selected:
> Get and select a mux-state if specified in dt, return error or NULL.
>
> Existing mux_get helper function is changed to take an extra argument
> indicating whether the mux is optional.
> In this case no error is printed, and NULL returned in case of ENOENT.
>
> Calling code is adapted to handle NULL return case, and to pass optional
> argument as required.
>
> To support automatic deselect for _selected helper, a new structure is
> created storing an exit pointer similar to clock core which is called on
> release.
>
> To facilitate code sharing between optional/mandatory/selected helpers,
> a new internal helper function is added to handle quiet (optional) and
> verbose (mandatory) errors, as well as storing the correct callback for
> devm release: __devm_mux_state_get
>
> Due to this structure devm_mux_state_get_*_selected can no longer print
> a useful error message when select fails. Instead callers should print
> errors where needed.
>
> Commit e153fdea9db04 ("phy: can-transceiver: Re-instate "mux-states"
> property presence check") noted that "mux_get() always prints an error
> message in case of an error, including when the property is not present,
> confusing the user."
>
> The first error message covers the case that a mux name is not matched
> in dt. The second error message is based on of_parse_phandle_with_args
> return value.
>
> In optional case no error is printed and NULL is returned.
> This ensures that the new helper functions will not confuse the user
> either.
>
> With the addition of optional helper functions it became clear that
> drivers should compile and link even if CONFIG_MULTIPLEXER was not enabled.
> Add stubs for all symbols exported by mux core.
>
> Signed-off-by: Josua Mayer <josua@solid-run.com>
Thanks for your patch!
> --- a/drivers/mux/core.c
> +++ b/drivers/mux/core.c
> @@ -46,6 +46,16 @@ static const struct class mux_class = {
> .name = "mux",
> };
>
> +/*
> + * struct devm_mux_state_state - Tracks managed resources for mux-state objects.
Please run scripts/checkpatch.pl:
WARNING: please, no space before tabs
#80: FILE: drivers/mux/core.c:50:
+ * struct devm_mux_state_state - ^ITracks managed resources for
mux-state objects.$
> + * @mux: Pointer to a mux state.
> + * @exit: An optional callback to execte before free.
> + */
> +struct devm_mux_state_state {
> + struct mux_state *mstate;
> + int (*exit)(struct mux_state *mstate);
> +};
> +
> static DEFINE_IDA(mux_ida);
>
> static int __init mux_init(void)
> --- a/include/linux/mux/consumer.h
> +++ b/include/linux/mux/consumer.h
> +static inline void mux_control_put(struct mux_control *mux)
> +{
> + return;
> +}
WARNING: void function return statements are not generally useful
#441: FILE: include/linux/mux/consumer.h:139:
+ return;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v5 3/7] mux: add help text for MULTIPLEXER config option
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
2026-01-18 10:28 ` [PATCH v5 1/7] phy: can-transceiver: rename temporary helper function to avoid conflict Josua Mayer
2026-01-18 10:28 ` [PATCH v5 2/7] mux: Add helper functions for getting optional and selected mux-state Josua Mayer
@ 2026-01-18 10:28 ` Josua Mayer
2026-01-18 10:29 ` [PATCH v5 4/7] phy: can-transceiver: drop temporary helper getting optional mux-state Josua Mayer
` (3 subsequent siblings)
6 siblings, 0 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:28 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Add help text for CONFIG_MULTIPLEXER to allow enabling this option
through the kernel configuration without explicit "select" driver
dependencies.
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/mux/Kconfig | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index c68132e38138..b2e1abc7c910 100644
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -5,6 +5,14 @@
config MULTIPLEXER
tristate
+ help
+ Generic Multiplexer Support.
+
+ This framework is designed to abstract multiplexer handling for
+ devices via various GPIO-, MMIO/Regmap or specific multiplexer
+ controller chips.
+
+ If unsure, say no.
menu "Multiplexer drivers"
depends on MULTIPLEXER
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v5 4/7] phy: can-transceiver: drop temporary helper getting optional mux-state
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
` (2 preceding siblings ...)
2026-01-18 10:28 ` [PATCH v5 3/7] mux: add help text for MULTIPLEXER config option Josua Mayer
@ 2026-01-18 10:29 ` Josua Mayer
2026-01-18 10:29 ` [PATCH v5 5/7] i2c: omap: switch to new generic helper for getting selected mux-state Josua Mayer
` (2 subsequent siblings)
6 siblings, 0 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:29 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Multiplexer subsystem has now added helpers for getting managed optional
mux-state.
Switch to the new devm_mux_state_get_optional helper.
This change is only compile-tested.
Acked-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/phy/phy-can-transceiver.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 81591d247128..2b52e47f247a 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -126,16 +126,6 @@ static const struct of_device_id can_transceiver_phy_ids[] = {
};
MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
-/* Temporary wrapper until the multiplexer subsystem supports optional muxes */
-static inline struct mux_state *
-temp_devm_mux_state_get_optional(struct device *dev, const char *mux_name)
-{
- if (!of_property_present(dev->of_node, "mux-states"))
- return NULL;
-
- return devm_mux_state_get(dev, mux_name);
-}
-
static struct phy *can_transceiver_phy_xlate(struct device *dev,
const struct of_phandle_args *args)
{
@@ -183,7 +173,7 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
priv->num_ch = num_ch;
platform_set_drvdata(pdev, priv);
- mux_state = temp_devm_mux_state_get_optional(dev, NULL);
+ mux_state = devm_mux_state_get_optional(dev, NULL);
if (IS_ERR(mux_state))
return PTR_ERR(mux_state);
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v5 5/7] i2c: omap: switch to new generic helper for getting selected mux-state
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
` (3 preceding siblings ...)
2026-01-18 10:29 ` [PATCH v5 4/7] phy: can-transceiver: drop temporary helper getting optional mux-state Josua Mayer
@ 2026-01-18 10:29 ` Josua Mayer
2026-01-18 10:29 ` [PATCH v5 6/7] dt-bindings: mmc: renesas,sdhi: Add mux-states property Josua Mayer
2026-01-18 10:29 ` [PATCH v5 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux Josua Mayer
6 siblings, 0 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:29 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Multiplexer subsystem has added generic helper functions for getting an
already selected mux-state object.
Replace existing logic in probe with the equivalent helper function.
There is a functional difference in that the mux is now automatically
deselected on release, replacing the explicit mux_state_deselect call.
This change is only compile-tested.
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/i2c/busses/i2c-omap.c | 24 +++++-------------------
1 file changed, 5 insertions(+), 19 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index d9f590f0c384..f02d294db42a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1453,27 +1453,16 @@ omap_i2c_probe(struct platform_device *pdev)
(1000 * omap->speed / 8);
}
- if (of_property_present(node, "mux-states")) {
- struct mux_state *mux_state;
-
- mux_state = devm_mux_state_get(&pdev->dev, NULL);
- if (IS_ERR(mux_state)) {
- r = PTR_ERR(mux_state);
- dev_dbg(&pdev->dev, "failed to get I2C mux: %d\n", r);
- goto err_put_pm;
- }
- omap->mux_state = mux_state;
- r = mux_state_select(omap->mux_state);
- if (r) {
- dev_err(&pdev->dev, "failed to select I2C mux: %d\n", r);
- goto err_put_pm;
- }
+ omap->mux_state = devm_mux_state_get_optional_selected(&pdev->dev, NULL);
+ if (IS_ERR(omap->mux_state)) {
+ r = PTR_ERR(omap->mux_state);
+ goto err_put_pm;
}
/* reset ASAP, clearing any IRQs */
r = omap_i2c_init(omap);
if (r)
- goto err_mux_state_deselect;
+ goto err_put_pm;
if (omap->rev < OMAP_I2C_OMAP1_REV_2)
r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr,
@@ -1515,9 +1504,6 @@ omap_i2c_probe(struct platform_device *pdev)
err_unuse_clocks:
omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
-err_mux_state_deselect:
- if (omap->mux_state)
- mux_state_deselect(omap->mux_state);
err_put_pm:
pm_runtime_put_sync(omap->dev);
err_disable_pm:
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v5 6/7] dt-bindings: mmc: renesas,sdhi: Add mux-states property
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
` (4 preceding siblings ...)
2026-01-18 10:29 ` [PATCH v5 5/7] i2c: omap: switch to new generic helper for getting selected mux-state Josua Mayer
@ 2026-01-18 10:29 ` Josua Mayer
2026-01-18 10:29 ` [PATCH v5 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux Josua Mayer
6 siblings, 0 replies; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:29 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Add mux controller support for data or control lines that are muxed
between a host and multiple cards.
There are several devices supporting a choice of eMMC or SD on a single
board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
SolidRun RZ/G2L SoM.
In-tree dts for the Renesas boards currently rely on preprocessor macros
and gpio hogs to describe the respective cards.
By adding mux-states property to sdhi controller description, boards can
correctly describe the mux that already exists in hardware - and drivers
can coordinate between mux selection and probing for cards.
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
index c754ea71f51f..64fac0d11329 100644
--- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
+++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
@@ -106,6 +106,11 @@ properties:
iommus:
maxItems: 1
+ mux-states:
+ description:
+ mux controller node to route the SD/SDIO/eMMC signals from SoC to cards.
+ maxItems: 1
+
power-domains:
maxItems: 1
@@ -275,6 +280,7 @@ examples:
max-frequency = <195000000>;
power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
resets = <&cpg 314>;
+ mux-states = <&mux 0>;
};
sdhi1: mmc@ee120000 {
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v5 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux
2026-01-18 10:28 [PATCH v5 0/7] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux Josua Mayer
` (5 preceding siblings ...)
2026-01-18 10:29 ` [PATCH v5 6/7] dt-bindings: mmc: renesas,sdhi: Add mux-states property Josua Mayer
@ 2026-01-18 10:29 ` Josua Mayer
2026-01-20 9:49 ` Geert Uytterhoeven
6 siblings, 1 reply; 14+ messages in thread
From: Josua Mayer @ 2026-01-18 10:29 UTC (permalink / raw)
To: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Geert Uytterhoeven, Magnus Damm, Wolfram Sang
Cc: Yazan Shhady, Jon Nettleton, Mikhail Anikin, linux-can, linux-phy,
linux-kernel, linux-omap, linux-i2c, linux-mmc, devicetree,
linux-renesas-soc, Josua Mayer
Some hardware designs route data or control signals through a mux to
support multiple devices on a single sdhi controller.
In particular SolidRun RZ/G2L/G2LC/V2L System on Module use a mux for
switching between soldered eMMC and an optional microSD on a carrier
board, e.g. for development or provisioning.
SD/SDIO/eMMC are not well suited for runtime switching between different
cards, however boot-time selection is possible and useful - in
particular considering dt overlays.
Add support for an optional SD/SDIO/eMMC mux defined in dt, and select
it during probe.
Similar functionality already exists in other places, e.g. i2c-omap.
Signed-off-by: Josua Mayer <josua@solid-run.com>
---
drivers/mmc/host/renesas_sdhi_core.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 2a310a145785..f9ec78d699f4 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -26,6 +26,7 @@
#include <linux/mmc/mmc.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/module.h>
+#include <linux/mux/consumer.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/pinctrl-state.h>
#include <linux/platform_data/tmio.h>
@@ -1062,6 +1063,7 @@ int renesas_sdhi_probe(struct platform_device *pdev,
struct regulator_dev *rdev;
struct renesas_sdhi_dma *dma_priv;
struct device *dev = &pdev->dev;
+ struct mux_state *mux_state;
struct tmio_mmc_host *host;
struct renesas_sdhi *priv;
int num_irqs, irq, ret, i;
@@ -1116,6 +1118,10 @@ int renesas_sdhi_probe(struct platform_device *pdev,
"state_uhs");
}
+ mux_state = devm_mux_state_get_optional_selected(&pdev->dev, NULL);
+ if (IS_ERR(mux_state))
+ return PTR_ERR(mux_state);
+
host = tmio_mmc_host_alloc(pdev, mmc_data);
if (IS_ERR(host))
return PTR_ERR(host);
--
2.43.0
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v5 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux
2026-01-18 10:29 ` [PATCH v5 7/7] mmc: host: renesas_sdhi_core: support selecting an optional mux Josua Mayer
@ 2026-01-20 9:49 ` Geert Uytterhoeven
0 siblings, 0 replies; 14+ messages in thread
From: Geert Uytterhoeven @ 2026-01-20 9:49 UTC (permalink / raw)
To: Josua Mayer
Cc: Marc Kleine-Budde, Vincent Mailhol, Vinod Koul, Neil Armstrong,
Peter Rosin, Aaro Koskinen, Andreas Kemnade, Kevin Hilman,
Roger Quadros, Tony Lindgren, Janusz Krzysztofik, Vignesh R,
Andi Shyti, Ulf Hansson, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Magnus Damm, Wolfram Sang, Yazan Shhady,
Jon Nettleton, Mikhail Anikin, linux-can, linux-phy, linux-kernel,
linux-omap, linux-i2c, linux-mmc, devicetree, linux-renesas-soc
On Sun, 18 Jan 2026 at 11:29, Josua Mayer <josua@solid-run.com> wrote:
> Some hardware designs route data or control signals through a mux to
> support multiple devices on a single sdhi controller.
>
> In particular SolidRun RZ/G2L/G2LC/V2L System on Module use a mux for
> switching between soldered eMMC and an optional microSD on a carrier
> board, e.g. for development or provisioning.
>
> SD/SDIO/eMMC are not well suited for runtime switching between different
> cards, however boot-time selection is possible and useful - in
> particular considering dt overlays.
>
> Add support for an optional SD/SDIO/eMMC mux defined in dt, and select
> it during probe.
>
> Similar functionality already exists in other places, e.g. i2c-omap.
>
> Signed-off-by: Josua Mayer <josua@solid-run.com>
LGTM, so
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 14+ messages in thread