Hi Greg!
Since last I improved a couple of commit messages. I.e. adding a body to
"mux: fix grammar, missing "is"."
and a Link tag to
"mux: Add support for reading mux state from consumer DT node"
Further, I removed the exports of the new functions mux_state_get()
and mux_state_put() as there are no users, not even in the wings as
is the case for devm_mux_state_get().
Cheers,
Peter
Aswath Govindraju (1):
mux: Add support for reading mux state from consumer DT node
Peter Rosin (2):
mux: add missing mux_state_get
mux: fix grammar, missing "is".
Yang Li (1):
mux: Fix struct mux_state kernel-doc comment
.../driver-api/driver-model/devres.rst | 1 +
drivers/mux/core.c | 239 ++++++++++++++++--
include/linux/mux/consumer.h | 18 ++
3 files changed, 236 insertions(+), 22 deletions(-)
From: Aswath Govindraju <[email protected]>
In some cases, we might need to provide the state of the mux to be set for
the operation of a given peripheral. Therefore, pass this information using
mux-states property.
Signed-off-by: Aswath Govindraju <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Peter Rosin <[email protected]> (minor edits)
---
.../driver-api/driver-model/devres.rst | 1 +
drivers/mux/core.c | 219 ++++++++++++++++--
include/linux/mux/consumer.h | 18 ++
3 files changed, 217 insertions(+), 21 deletions(-)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 148e19381b79..5018403fe82f 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -368,6 +368,7 @@ MUX
devm_mux_chip_alloc()
devm_mux_chip_register()
devm_mux_control_get()
+ devm_mux_state_get()
NET
devm_alloc_etherdev()
diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 22f4709768d1..931fa8bd4962 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -29,6 +29,20 @@
*/
#define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS
+/**
+ * struct mux_state - Represents a mux controller state specific to a given
+ * consumer.
+ * @mux: Pointer to a mux controller.
+ * @state State of the mux to be selected.
+ *
+ * This structure is specific to the consumer that acquires it and has
+ * information specific to that consumer.
+ */
+struct mux_state {
+ struct mux_control *mux;
+ unsigned int state;
+};
+
static struct class mux_class = {
.name = "mux",
.owner = THIS_MODULE,
@@ -341,7 +355,8 @@ static void mux_control_delay(struct mux_control *mux, unsigned int delay_us)
* On successfully selecting the mux-control state, it will be locked until
* there is a call to mux_control_deselect(). If the mux-control is already
* selected when mux_control_select() is called, the caller will be blocked
- * until mux_control_deselect() is called (by someone else).
+ * until mux_control_deselect() or mux_state_deselect() is called (by someone
+ * else).
*
* Therefore, make sure to call mux_control_deselect() when the operation is
* complete and the mux-control is free for others to use, but do not call
@@ -370,6 +385,30 @@ int mux_control_select_delay(struct mux_control *mux, unsigned int state,
}
EXPORT_SYMBOL_GPL(mux_control_select_delay);
+/**
+ * mux_state_select_delay() - Select the given multiplexer state.
+ * @mstate: The mux-state to select.
+ * @delay_us: The time to delay (in microseconds) if the mux state is changed.
+ *
+ * On successfully selecting the mux-state, its mux-control will be locked
+ * until there is a call to mux_state_deselect(). If the mux-control is already
+ * selected when mux_state_select() is called, the caller will be blocked
+ * until mux_state_deselect() or mux_control_deselect() is called (by someone
+ * else).
+ *
+ * Therefore, make sure to call mux_state_deselect() when the operation is
+ * complete and the mux-control is free for others to use, but do not call
+ * mux_state_deselect() if mux_state_select() fails.
+ *
+ * Return: 0 when the mux-state has been selected or a negative
+ * errno on error.
+ */
+int mux_state_select_delay(struct mux_state *mstate, unsigned int delay_us)
+{
+ return mux_control_select_delay(mstate->mux, mstate->state, delay_us);
+}
+EXPORT_SYMBOL_GPL(mux_state_select_delay);
+
/**
* mux_control_try_select_delay() - Try to select the given multiplexer state.
* @mux: The mux-control to request a change of state from.
@@ -405,6 +444,27 @@ int mux_control_try_select_delay(struct mux_control *mux, unsigned int state,
}
EXPORT_SYMBOL_GPL(mux_control_try_select_delay);
+/**
+ * mux_state_try_select_delay() - Try to select the given multiplexer state.
+ * @mstate: The mux-state to select.
+ * @delay_us: The time to delay (in microseconds) if the mux state is changed.
+ *
+ * On successfully selecting the mux-state, its mux-control will be locked
+ * until mux_state_deselect() is called.
+ *
+ * Therefore, make sure to call mux_state_deselect() when the operation is
+ * complete and the mux-control is free for others to use, but do not call
+ * mux_state_deselect() if mux_state_try_select() fails.
+ *
+ * Return: 0 when the mux-state has been selected or a negative errno on
+ * error. Specifically -EBUSY if the mux-control is contended.
+ */
+int mux_state_try_select_delay(struct mux_state *mstate, unsigned int delay_us)
+{
+ return mux_control_try_select_delay(mstate->mux, mstate->state, delay_us);
+}
+EXPORT_SYMBOL_GPL(mux_state_try_select_delay);
+
/**
* mux_control_deselect() - Deselect the previously selected multiplexer state.
* @mux: The mux-control to deselect.
@@ -431,6 +491,24 @@ int mux_control_deselect(struct mux_control *mux)
}
EXPORT_SYMBOL_GPL(mux_control_deselect);
+/**
+ * mux_state_deselect() - Deselect the previously selected multiplexer state.
+ * @mstate: The mux-state to deselect.
+ *
+ * It is required that a single call is made to mux_state_deselect() for
+ * each and every successful call made to either of mux_state_select() or
+ * mux_state_try_select().
+ *
+ * Return: 0 on success and a negative errno on error. An error can only
+ * occur if the mux has an idle state. Note that even if an error occurs, the
+ * mux-control is unlocked and is thus free for the next access.
+ */
+int mux_state_deselect(struct mux_state *mstate)
+{
+ return mux_control_deselect(mstate->mux);
+}
+EXPORT_SYMBOL_GPL(mux_state_deselect);
+
/* Note this function returns a reference to the mux_chip dev. */
static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
{
@@ -441,14 +519,17 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
return dev ? to_mux_chip(dev) : NULL;
}
-/**
- * mux_control_get() - Get the mux-control for a device.
+/*
+ * mux_get() - Get the mux-control for a device.
* @dev: The device that needs a mux-control.
* @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.
*
* Return: A pointer to the mux-control, or an ERR_PTR with a negative errno.
*/
-struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
+static struct mux_control *mux_get(struct device *dev, const char *mux_name,
+ unsigned int *state)
{
struct device_node *np = dev->of_node;
struct of_phandle_args args;
@@ -458,8 +539,12 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
int ret;
if (mux_name) {
- index = of_property_match_string(np, "mux-control-names",
- mux_name);
+ if (state)
+ index = of_property_match_string(np, "mux-state-names",
+ mux_name);
+ else
+ index = of_property_match_string(np, "mux-control-names",
+ mux_name);
if (index < 0) {
dev_err(dev, "mux controller '%s' not found\n",
mux_name);
@@ -467,12 +552,17 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
}
}
- ret = of_parse_phandle_with_args(np,
- "mux-controls", "#mux-control-cells",
- index, &args);
+ if (state)
+ ret = of_parse_phandle_with_args(np,
+ "mux-states", "#mux-state-cells",
+ index, &args);
+ else
+ ret = of_parse_phandle_with_args(np,
+ "mux-controls", "#mux-control-cells",
+ index, &args);
if (ret) {
- dev_err(dev, "%pOF: failed to get mux-control %s(%i)\n",
- np, mux_name ?: "", index);
+ dev_err(dev, "%pOF: failed to get mux-%s %s(%i)\n",
+ np, state ? "state" : "control", mux_name ?: "", index);
return ERR_PTR(ret);
}
@@ -481,17 +571,35 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
if (!mux_chip)
return ERR_PTR(-EPROBE_DEFER);
- if (args.args_count > 1 ||
- (!args.args_count && (mux_chip->controllers > 1))) {
- dev_err(dev, "%pOF: wrong #mux-control-cells for %pOF\n",
- np, args.np);
- put_device(&mux_chip->dev);
- return ERR_PTR(-EINVAL);
- }
-
controller = 0;
- if (args.args_count)
- controller = args.args[0];
+ if (state) {
+ if (args.args_count > 2 || args.args_count == 0 ||
+ (args.args_count < 2 && mux_chip->controllers > 1)) {
+ dev_err(dev, "%pOF: wrong #mux-state-cells for %pOF\n",
+ np, args.np);
+ put_device(&mux_chip->dev);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (args.args_count == 2) {
+ controller = args.args[0];
+ *state = args.args[1];
+ } else {
+ *state = args.args[0];
+ }
+
+ } else {
+ if (args.args_count > 1 ||
+ (!args.args_count && mux_chip->controllers > 1)) {
+ dev_err(dev, "%pOF: wrong #mux-control-cells for %pOF\n",
+ np, args.np);
+ put_device(&mux_chip->dev);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (args.args_count)
+ controller = args.args[0];
+ }
if (controller >= mux_chip->controllers) {
dev_err(dev, "%pOF: bad mux controller %u specified in %pOF\n",
@@ -502,6 +610,18 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
return &mux_chip->mux[controller];
}
+
+/**
+ * mux_control_get() - Get the 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, or an ERR_PTR with a negative errno.
+ */
+struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
+{
+ return mux_get(dev, mux_name, NULL);
+}
EXPORT_SYMBOL_GPL(mux_control_get);
/**
@@ -553,6 +673,63 @@ struct mux_control *devm_mux_control_get(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_mux_control_get);
+/*
+ * mux_state_put() - Put away the mux-state for good.
+ * @mstate: The mux-state to put away.
+ *
+ * mux_state_put() reverses the effects of mux_state_get().
+ */
+static void mux_state_put(struct mux_state *mstate)
+{
+ mux_control_put(mstate->mux);
+ kfree(mstate);
+}
+
+static void devm_mux_state_release(struct device *dev, void *res)
+{
+ struct mux_state *mstate = *(struct mux_state **)res;
+
+ mux_state_put(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.
+ *
+ * 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)
+{
+ struct mux_state **ptr, *mstate;
+ struct mux_control *mux_ctrl;
+ int state;
+
+ mstate = devm_kzalloc(dev, sizeof(struct mux_state), GFP_KERNEL);
+ if (!mstate)
+ return ERR_PTR(-ENOMEM);
+
+ ptr = devres_alloc(devm_mux_state_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ mux_ctrl = mux_get(dev, mux_name, &state);
+ if (IS_ERR(mux_ctrl)) {
+ devres_free(ptr);
+ return (struct mux_state *)mux_ctrl;
+ }
+
+ mstate->mux = mux_ctrl;
+ mstate->state = state;
+ *ptr = mstate;
+ devres_add(dev, ptr);
+
+ return mstate;
+}
+EXPORT_SYMBOL_GPL(devm_mux_state_get);
+
/*
* 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 7a09b040ac39..2e25c838f831 100644
--- a/include/linux/mux/consumer.h
+++ b/include/linux/mux/consumer.h
@@ -14,14 +14,19 @@
struct device;
struct mux_control;
+struct mux_state;
unsigned int mux_control_states(struct mux_control *mux);
int __must_check mux_control_select_delay(struct mux_control *mux,
unsigned int state,
unsigned int delay_us);
+int __must_check mux_state_select_delay(struct mux_state *mstate,
+ unsigned int delay_us);
int __must_check mux_control_try_select_delay(struct mux_control *mux,
unsigned int state,
unsigned int delay_us);
+int __must_check mux_state_try_select_delay(struct mux_state *mstate,
+ unsigned int delay_us);
static inline int __must_check mux_control_select(struct mux_control *mux,
unsigned int state)
@@ -29,18 +34,31 @@ static inline int __must_check mux_control_select(struct mux_control *mux,
return mux_control_select_delay(mux, state, 0);
}
+static inline int __must_check mux_state_select(struct mux_state *mstate)
+{
+ return mux_state_select_delay(mstate, 0);
+}
+
static inline int __must_check mux_control_try_select(struct mux_control *mux,
unsigned int state)
{
return mux_control_try_select_delay(mux, state, 0);
}
+static inline int __must_check mux_state_try_select(struct mux_state *mstate)
+{
+ return mux_state_try_select_delay(mstate, 0);
+}
+
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);
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);
#endif /* _LINUX_MUX_CONSUMER_H */
--
2.20.1
And implement devm_mux_state_get in terms of the new function.
Now we have both mux_state_get and mux_state_put as convenient functions
ready to be exported should someone ever need unmanaged interfaces.
Tested-by: Aswath Govindraju <[email protected]>
Signed-off-by: Peter Rosin <[email protected]>
---
drivers/mux/core.c | 40 +++++++++++++++++++++++++++++-----------
1 file changed, 29 insertions(+), 11 deletions(-)
diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 931fa8bd4962..5cf2124fa55b 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -673,6 +673,32 @@ struct mux_control *devm_mux_control_get(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_mux_control_get);
+/*
+ * mux_state_get() - Get the mux-state for a device.
+ * @dev: The device that needs a mux-state.
+ * @mux_name: The name identifying the mux-state.
+ *
+ * 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)
+{
+ struct mux_state *mstate;
+
+ mstate = kzalloc(sizeof(*mstate), GFP_KERNEL);
+ 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);
+
+ kfree(mstate);
+ return ERR_PTR(err);
+ }
+
+ return mstate;
+}
+
/*
* mux_state_put() - Put away the mux-state for good.
* @mstate: The mux-state to put away.
@@ -704,25 +730,17 @@ struct mux_state *devm_mux_state_get(struct device *dev,
const char *mux_name)
{
struct mux_state **ptr, *mstate;
- struct mux_control *mux_ctrl;
- int state;
-
- mstate = devm_kzalloc(dev, sizeof(struct mux_state), GFP_KERNEL);
- if (!mstate)
- return ERR_PTR(-ENOMEM);
ptr = devres_alloc(devm_mux_state_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
- mux_ctrl = mux_get(dev, mux_name, &state);
- if (IS_ERR(mux_ctrl)) {
+ mstate = mux_state_get(dev, mux_name);
+ if (IS_ERR(mstate)) {
devres_free(ptr);
- return (struct mux_state *)mux_ctrl;
+ return mstate;
}
- mstate->mux = mux_ctrl;
- mstate->state = state;
*ptr = mstate;
devres_add(dev, ptr);
--
2.20.1
This makes it easier to parse.
Signed-off-by: Peter Rosin <[email protected]>
---
drivers/mux/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 5cf2124fa55b..1a76a536d4b1 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -416,7 +416,7 @@ EXPORT_SYMBOL_GPL(mux_state_select_delay);
* @delay_us: The time to delay (in microseconds) if the mux state is changed.
*
* On successfully selecting the mux-control state, it will be locked until
- * mux_control_deselect() called.
+ * mux_control_deselect() is called.
*
* Therefore, make sure to call mux_control_deselect() when the operation is
* complete and the mux-control is free for others to use, but do not call
--
2.20.1
From: Yang Li <[email protected]>
A warning is reported because a colon was dropped, it is found by running
scripts/kernel-doc, which is caused by using 'make W=1'.
drivers/mux/core.c:44: warning: Function parameter or member 'state' not
described in 'mux_state'
Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
Signed-off-by: Peter Rosin <[email protected]>
---
drivers/mux/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 1a76a536d4b1..49bedbe6316c 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -33,7 +33,7 @@
* struct mux_state - Represents a mux controller state specific to a given
* consumer.
* @mux: Pointer to a mux controller.
- * @state State of the mux to be selected.
+ * @state: State of the mux to be selected.
*
* This structure is specific to the consumer that acquires it and has
* information specific to that consumer.
--
2.20.1
On Fri, Jan 07, 2022 at 08:43:43AM +0100, Peter Rosin wrote:
> Hi Greg!
>
> Since last I improved a couple of commit messages. I.e. adding a body to
> "mux: fix grammar, missing "is"."
> and a Link tag to
> "mux: Add support for reading mux state from consumer DT node"
>
> Further, I removed the exports of the new functions mux_state_get()
> and mux_state_put() as there are no users, not even in the wings as
> is the case for devm_mux_state_get().
>
> Cheers,
> Peter
>
> Aswath Govindraju (1):
> mux: Add support for reading mux state from consumer DT node
>
> Peter Rosin (2):
> mux: add missing mux_state_get
> mux: fix grammar, missing "is".
>
> Yang Li (1):
> mux: Fix struct mux_state kernel-doc comment
>
> .../driver-api/driver-model/devres.rst | 1 +
> drivers/mux/core.c | 239 ++++++++++++++++--
> include/linux/mux/consumer.h | 18 ++
> 3 files changed, 236 insertions(+), 22 deletions(-)
>
Sorry for the delay, now applied.
greg k-h