* [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks
@ 2026-01-18 15:44 Kurt Borja
2026-01-18 15:44 ` [PATCH v4 1/7] iio: core: Add and export __iio_dev_mode_lock() Kurt Borja
` (6 more replies)
0 siblings, 7 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Hi,
In a recent driver review discussion [1], Andy Shevchenko suggested we
add cleanup.h support for the lock API:
iio_device_claim_{direct,buffer_mode}().
Which would allow some nice code simplification in many places. Some
examples are given as patches, but the last two are the biggest
differences.
In this version I dropped the RFC tag, as the general feeling is to go
through with this after some modifications. Main one is the addition of
IIO_DEV_ACQUIRE_{BUFFER,CLAIM}_MODE() wrappers to avoid drivers using
the guard classes directly. I also added comments on the forbidden ways
to use this API but I definitely still take suggestions on this.
For now I dropped iio_device_claim_buffer_mode() rename, as this point
is still being discussed. My suggestion based on the RFC discussion is
to do it, but in a separate patch (using coccinelle) and while we're at
it rename the whole API like this:
iio_dev_mode_lock()
iio_dev_mode_direct_trylock()
iio_dev_mode_buffer_trylock()
iio_dev_mode_unlock()
Let me know what you think and thanks for taking a look!
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
v4:
- Replace "," with ";" in __iio_dev_mode_lock() docs.
- Fix "bellow" -> "below" typo.
- Drop first example in IIO_DEV_ACQUIRE_DIRECT_MODE() docs.
- Match variable names in kernel-doc and definitions.
- Replace "markings" with "annotations" in the "static inline" remark
- Replace "claim_ptr" with "claim" in IIO_DEV_ACQUIRE_FAILED() and get
the pointer inside.
v3: https://lore.kernel.org/r/20260106-lock-impr-v3-0-1db909b192c0@gmail.com
- Reword commit message of patch 1: infallible -> unconditional.
- Drop "*strongly*" in __iio_dev_mode_lock() kernel-doc and be a bit
more clear on the function's intention.
- Keep comment about inline functions and sparse markings, but drop
the __cond_acquires() part, as the new implementation makes it
unnecessary.
- Implement iio_device_release_*() as macros around
__iio_dev_mode_unlock().
- Rename iio_device_claim_buffer_mode() ->
iio_device_try_claim_buffer_mode() to avoid silently breaking
out-of-tree drivers.
- Drop the `_` argument prefix in new macros, as there are no name
conflicts.
- Drop "dummy" from IIO_DEV_ACQUIRE_DIRECT_MODE kernel-doc, as the
`claim` variable does store the error value.
- Drop IIO_DEV_ACQUIRE_BUFFER_MODE() until a driver actually needs it.
- Rename IIO_DEV_ACQUIRE_ERR() -> IIO_DEV_ACQUIRE_FAILED() to make the
name more clear.
- Rename IIO_DEV_GUARD_ANY_MODE() -> IIO_DEV_GUARD_CURRENT_MODE() to
make the name more clear.
- Add missing . in iio_device_release_direct() kernel-doc.
NOTE: Andy suggested __iio_dev_mode_*() be exported into the IIO_CORE
namespace. However, this cannot be done because these functions
need to be called inline, so Sparse can see the __acquires() and
__releases() tags.
Happy new year to everyone :)
v2: https://lore.kernel.org/r/20251211-lock-impr-v2-0-6fb47bdaaf24@gmail.com
- Add __iio_dev_mode_lock() (formerly iio_device_claim()) in the first
patch.
- Added comments to make sure __iio_dev_mode_lock() is not used by
drivers to protect internal state, or in general.
- Add patch which re-implements iio_device_claim_direct() using
__iio_dev_mode_lock().
- Match iio_device_claim_buffer_mode() semantics by reimplementing it
in the same way as iio_device_claim_direct().
- Guard classes now are prefixed with __priv__ to make sure drivers
don't use them directly.
- Add IIO_DEV_ACQUIRE_{BUFFER,DIRECT}_MODE() documented wrappers
- Avoid any function renames (for now).
- Rename dummy variable `claim` instead of `busy` on vcnl4000 patch.
- Avoid scoped guard in max30102.
- Keep using iio_trigger_validate_own_device() insted of
iio_trigger_using_own() in opt4060.
v1: https://lore.kernel.org/r/20251203-lock-impr-v1-0-b4a1fd639423@gmail.com
---
Kurt Borja (7):
iio: core: Add and export __iio_dev_mode_lock()
iio: core: Refactor iio_device_claim_direct() implementation
iio: core: Match iio_device_claim_*() semantics and implementation
iio: core: Add cleanup.h support for iio_device_claim_*()
iio: light: vcnl4000: Use IIO cleanup helpers
iio: health: max30102: Use IIO cleanup helpers
iio: light: opt4060: Use IIO cleanup helpers
drivers/iio/adc/ade9000.c | 2 +-
.../common/cros_ec_sensors/cros_ec_sensors_core.c | 5 +-
drivers/iio/health/max30100.c | 8 +-
drivers/iio/health/max30102.c | 33 ++---
drivers/iio/industrialio-core.c | 86 +++----------
drivers/iio/light/opt4060.c | 52 +++-----
drivers/iio/light/vcnl4000.c | 49 +++-----
include/linux/iio/iio.h | 139 +++++++++++++++++++--
8 files changed, 190 insertions(+), 184 deletions(-)
---
base-commit: c30e80d68a7afb334fde7147ee0106f25dd58d3a
change-id: 20251130-lock-impr-6f22748c15e8
--
~ Kurt
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v4 1/7] iio: core: Add and export __iio_dev_mode_lock()
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 2/7] iio: core: Refactor iio_device_claim_direct() implementation Kurt Borja
` (5 subsequent siblings)
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Add unconditional wrappers around the internal IIO mode lock.
As mentioned in the documentation, this is not meant to be used by
drivers, instead this will aid in the eventual addition of cleanup
classes around conditional locks.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/industrialio-core.c | 30 ++++++++++++++++++++++++++++++
include/linux/iio/iio.h | 3 +++
2 files changed, 33 insertions(+)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index f69deefcfb6f..9693a6bb3917 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2171,6 +2171,36 @@ int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
}
EXPORT_SYMBOL_GPL(__devm_iio_device_register);
+/**
+ * __iio_dev_mode_lock - Locks the current IIO device mode
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * If the device is either in direct or buffer mode, it's guaranteed to stay
+ * that way until __iio_dev_mode_unlock() is called.
+ *
+ * This function is not meant to be used directly by drivers to protect internal
+ * state; a driver should have it's own mechanisms for that matter.
+ *
+ * There are very few cases where a driver actually needs to lock the current
+ * mode unconditionally. It's recommended to use iio_device_claim_direct() or
+ * iio_device_claim_buffer_mode() pairs or related helpers instead.
+ */
+void __iio_dev_mode_lock(struct iio_dev *indio_dev)
+{
+ mutex_lock(&to_iio_dev_opaque(indio_dev)->mlock);
+}
+EXPORT_SYMBOL_GPL(__iio_dev_mode_lock);
+
+/**
+ * __iio_dev_mode_unlock - Unlocks the current IIO device mode
+ * @indio_dev: the iio_dev associated with the device
+ */
+void __iio_dev_mode_unlock(struct iio_dev *indio_dev)
+{
+ mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
+}
+EXPORT_SYMBOL_GPL(__iio_dev_mode_unlock);
+
/**
* __iio_device_claim_direct - Keep device in direct mode
* @indio_dev: the iio_dev associated with the device
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 872ebdf0dd77..aecda887d833 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -661,6 +661,9 @@ void iio_device_unregister(struct iio_dev *indio_dev);
int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
struct module *this_mod);
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
+
+void __iio_dev_mode_lock(struct iio_dev *indio_dev) __acquires(indio_dev);
+void __iio_dev_mode_unlock(struct iio_dev *indio_dev) __releases(indio_dev);
bool __iio_device_claim_direct(struct iio_dev *indio_dev);
void __iio_device_release_direct(struct iio_dev *indio_dev);
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 2/7] iio: core: Refactor iio_device_claim_direct() implementation
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
2026-01-18 15:44 ` [PATCH v4 1/7] iio: core: Add and export __iio_dev_mode_lock() Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 3/7] iio: core: Match iio_device_claim_*() semantics and implementation Kurt Borja
` (4 subsequent siblings)
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
In order to eventually unify the locking API, implement
iio_device_claim_direct() fully inline, with the use of
__iio_dev_mode_lock(), which takes care of sparse annotations.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/industrialio-core.c | 44 -----------------------------------------
include/linux/iio/iio.h | 40 ++++++++++++++++++++++++++-----------
2 files changed, 28 insertions(+), 56 deletions(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 9693a6bb3917..83078285cd97 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2201,50 +2201,6 @@ void __iio_dev_mode_unlock(struct iio_dev *indio_dev)
}
EXPORT_SYMBOL_GPL(__iio_dev_mode_unlock);
-/**
- * __iio_device_claim_direct - Keep device in direct mode
- * @indio_dev: the iio_dev associated with the device
- *
- * If the device is in direct mode it is guaranteed to stay
- * that way until __iio_device_release_direct() is called.
- *
- * Use with __iio_device_release_direct().
- *
- * Drivers should only call iio_device_claim_direct().
- *
- * Returns: true on success, false on failure.
- */
-bool __iio_device_claim_direct(struct iio_dev *indio_dev)
-{
- struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
-
- mutex_lock(&iio_dev_opaque->mlock);
-
- if (iio_buffer_enabled(indio_dev)) {
- mutex_unlock(&iio_dev_opaque->mlock);
- return false;
- }
- return true;
-}
-EXPORT_SYMBOL_GPL(__iio_device_claim_direct);
-
-/**
- * __iio_device_release_direct - releases claim on direct mode
- * @indio_dev: the iio_dev associated with the device
- *
- * Release the claim. Device is no longer guaranteed to stay
- * in direct mode.
- *
- * Drivers should only call iio_device_release_direct().
- *
- * Use with __iio_device_claim_direct()
- */
-void __iio_device_release_direct(struct iio_dev *indio_dev)
-{
- mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
-}
-EXPORT_SYMBOL_GPL(__iio_device_release_direct);
-
/**
* iio_device_claim_buffer_mode - Keep device in buffer mode
* @indio_dev: the iio_dev associated with the device
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index aecda887d833..f6d494065efe 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -664,31 +664,47 @@ int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
void __iio_dev_mode_lock(struct iio_dev *indio_dev) __acquires(indio_dev);
void __iio_dev_mode_unlock(struct iio_dev *indio_dev) __releases(indio_dev);
-bool __iio_device_claim_direct(struct iio_dev *indio_dev);
-void __iio_device_release_direct(struct iio_dev *indio_dev);
/*
* Helper functions that allow claim and release of direct mode
* in a fashion that doesn't generate many false positives from sparse.
* Note this must remain static inline in the header so that sparse
- * can see the __acquire() marking. Revisit when sparse supports
- * __cond_acquires()
+ * can see the __acquires() and __releases() annotations.
+ */
+
+/**
+ * iio_device_claim_direct - Keep device in direct mode
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * If the device is in direct mode it is guaranteed to stay
+ * that way until iio_device_release_direct() is called.
+ *
+ * Use with iio_device_release_direct().
+ *
+ * Returns: true on success, false on failure.
*/
static inline bool iio_device_claim_direct(struct iio_dev *indio_dev)
{
- if (!__iio_device_claim_direct(indio_dev))
- return false;
+ __iio_dev_mode_lock(indio_dev);
- __acquire(iio_dev);
+ if (iio_buffer_enabled(indio_dev)) {
+ __iio_dev_mode_unlock(indio_dev);
+ return false;
+ }
return true;
}
-static inline void iio_device_release_direct(struct iio_dev *indio_dev)
-{
- __iio_device_release_direct(indio_dev);
- __release(indio_dev);
-}
+/**
+ * iio_device_release_direct - Releases claim on direct mode
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * Release the claim. Device is no longer guaranteed to stay
+ * in direct mode.
+ *
+ * Use with iio_device_claim_direct().
+ */
+#define iio_device_release_direct(indio_dev) __iio_dev_mode_unlock(indio_dev)
int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
void iio_device_release_buffer_mode(struct iio_dev *indio_dev);
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 3/7] iio: core: Match iio_device_claim_*() semantics and implementation
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
2026-01-18 15:44 ` [PATCH v4 1/7] iio: core: Add and export __iio_dev_mode_lock() Kurt Borja
2026-01-18 15:44 ` [PATCH v4 2/7] iio: core: Refactor iio_device_claim_direct() implementation Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*() Kurt Borja
` (3 subsequent siblings)
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Implement iio_device_claim_buffer_mode() fully inline with the use of
__iio_dev_mode_lock(), which takes care of sparse annotations.
To completely match iio_device_claim_direct() semantics, we need to
also change iio_device_claim_buffer_mode() return semantics to usual
true/false conditional lock semantics.
Additionally, to avoid silently breaking out-of-tree drivers, rename
iio_device_claim_buffer_mode() to iio_device_claim_try_buffer_mode().
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/adc/ade9000.c | 2 +-
.../common/cros_ec_sensors/cros_ec_sensors_core.c | 5 +--
drivers/iio/health/max30100.c | 8 +----
drivers/iio/health/max30102.c | 2 +-
drivers/iio/industrialio-core.c | 42 +---------------------
drivers/iio/light/opt4060.c | 2 +-
include/linux/iio/iio.h | 35 ++++++++++++++++--
7 files changed, 39 insertions(+), 57 deletions(-)
diff --git a/drivers/iio/adc/ade9000.c b/drivers/iio/adc/ade9000.c
index 2de8a718d62a..db085dc5e526 100644
--- a/drivers/iio/adc/ade9000.c
+++ b/drivers/iio/adc/ade9000.c
@@ -964,7 +964,7 @@ static irqreturn_t ade9000_dready_thread(int irq, void *data)
struct iio_dev *indio_dev = data;
/* Handle data ready interrupt from C4/EVENT/DREADY pin */
- if (!iio_device_claim_buffer_mode(indio_dev)) {
+ if (iio_device_try_claim_buffer_mode(indio_dev)) {
ade9000_iio_push_buffer(indio_dev);
iio_device_release_buffer_mode(indio_dev);
}
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 9ac80e4b7d75..ef53066b1735 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -188,11 +188,8 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
/*
* Ignore samples if the buffer is not set: it is needed if the ODR is
* set but the buffer is not enabled yet.
- *
- * Note: iio_device_claim_buffer_mode() returns -EBUSY if the buffer
- * is not enabled.
*/
- if (iio_device_claim_buffer_mode(indio_dev) < 0)
+ if (!iio_device_try_claim_buffer_mode(indio_dev))
return 0;
out = (s16 *)st->samples;
diff --git a/drivers/iio/health/max30100.c b/drivers/iio/health/max30100.c
index 3d441013893c..7dfdb5eb305e 100644
--- a/drivers/iio/health/max30100.c
+++ b/drivers/iio/health/max30100.c
@@ -417,13 +417,7 @@ static int max30100_read_raw(struct iio_dev *indio_dev,
* Temperature reading can only be acquired while engine
* is running
*/
- if (iio_device_claim_buffer_mode(indio_dev)) {
- /*
- * Replacing -EBUSY or other error code
- * returned by iio_device_claim_buffer_mode()
- * because user space may rely on the current
- * one.
- */
+ if (!iio_device_try_claim_buffer_mode(indio_dev)) {
ret = -EAGAIN;
} else {
ret = max30100_get_temp(data, val);
diff --git a/drivers/iio/health/max30102.c b/drivers/iio/health/max30102.c
index a48c0881a4c7..6918fcb5de2b 100644
--- a/drivers/iio/health/max30102.c
+++ b/drivers/iio/health/max30102.c
@@ -476,7 +476,7 @@ static int max30102_read_raw(struct iio_dev *indio_dev,
* shutdown; leave shutdown briefly when buffer not running
*/
any_mode_retry:
- if (iio_device_claim_buffer_mode(indio_dev)) {
+ if (!iio_device_try_claim_buffer_mode(indio_dev)) {
/*
* This one is a *bit* hacky. If we cannot claim buffer
* mode, then try direct mode so that we make sure
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 83078285cd97..20cf316664b4 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2183,7 +2183,7 @@ EXPORT_SYMBOL_GPL(__devm_iio_device_register);
*
* There are very few cases where a driver actually needs to lock the current
* mode unconditionally. It's recommended to use iio_device_claim_direct() or
- * iio_device_claim_buffer_mode() pairs or related helpers instead.
+ * iio_device_try_claim_buffer_mode() pairs or related helpers instead.
*/
void __iio_dev_mode_lock(struct iio_dev *indio_dev)
{
@@ -2201,46 +2201,6 @@ void __iio_dev_mode_unlock(struct iio_dev *indio_dev)
}
EXPORT_SYMBOL_GPL(__iio_dev_mode_unlock);
-/**
- * iio_device_claim_buffer_mode - Keep device in buffer mode
- * @indio_dev: the iio_dev associated with the device
- *
- * If the device is in buffer mode it is guaranteed to stay
- * that way until iio_device_release_buffer_mode() is called.
- *
- * Use with iio_device_release_buffer_mode().
- *
- * Returns: 0 on success, -EBUSY on failure.
- */
-int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
-{
- struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
-
- mutex_lock(&iio_dev_opaque->mlock);
-
- if (iio_buffer_enabled(indio_dev))
- return 0;
-
- mutex_unlock(&iio_dev_opaque->mlock);
- return -EBUSY;
-}
-EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
-
-/**
- * iio_device_release_buffer_mode - releases claim on buffer mode
- * @indio_dev: the iio_dev associated with the device
- *
- * Release the claim. Device is no longer guaranteed to stay
- * in buffer mode.
- *
- * Use with iio_device_claim_buffer_mode().
- */
-void iio_device_release_buffer_mode(struct iio_dev *indio_dev)
-{
- mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
-}
-EXPORT_SYMBOL_GPL(iio_device_release_buffer_mode);
-
/**
* iio_device_get_current_mode() - helper function providing read-only access to
* the opaque @currentmode variable
diff --git a/drivers/iio/light/opt4060.c b/drivers/iio/light/opt4060.c
index 981c704e7df5..8c4a1f562a83 100644
--- a/drivers/iio/light/opt4060.c
+++ b/drivers/iio/light/opt4060.c
@@ -304,7 +304,7 @@ static int opt4060_set_driver_state(struct iio_dev *indio_dev,
struct opt4060_chip *chip = iio_priv(indio_dev);
int ret = 0;
any_mode_retry:
- if (iio_device_claim_buffer_mode(indio_dev)) {
+ if (!iio_device_try_claim_buffer_mode(indio_dev)) {
/*
* This one is a *bit* hacky. If we cannot claim buffer mode,
* then try direct mode so that we make sure things cannot
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index f6d494065efe..fa671e120e95 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -706,8 +706,39 @@ static inline bool iio_device_claim_direct(struct iio_dev *indio_dev)
*/
#define iio_device_release_direct(indio_dev) __iio_dev_mode_unlock(indio_dev)
-int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
-void iio_device_release_buffer_mode(struct iio_dev *indio_dev);
+/**
+ * iio_device_try_claim_buffer_mode - Keep device in buffer mode
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * If the device is in buffer mode it is guaranteed to stay
+ * that way until iio_device_release_buffer_mode() is called.
+ *
+ * Use with iio_device_release_buffer_mode().
+ *
+ * Returns: true on success, false on failure.
+ */
+static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev)
+{
+ __iio_dev_mode_lock(indio_dev);
+
+ if (!iio_buffer_enabled(indio_dev)) {
+ __iio_dev_mode_unlock(indio_dev);
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * iio_device_release_buffer_mode - releases claim on buffer mode
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * Release the claim. Device is no longer guaranteed to stay
+ * in buffer mode.
+ *
+ * Use with iio_device_try_claim_buffer_mode().
+ */
+#define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev)
extern const struct bus_type iio_bus_type;
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
` (2 preceding siblings ...)
2026-01-18 15:44 ` [PATCH v4 3/7] iio: core: Match iio_device_claim_*() semantics and implementation Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 19:35 ` David Lechner
2026-01-19 8:15 ` Andy Shevchenko
2026-01-18 15:44 ` [PATCH v4 5/7] iio: light: vcnl4000: Use IIO cleanup helpers Kurt Borja
` (2 subsequent siblings)
6 siblings, 2 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Add guard classes for iio_device_claim_*() conditional locks. This will
aid drivers write safer and cleaner code when dealing with some common
patterns.
These classes are not meant to be used directly by drivers (hence the
__priv__ prefix). Instead, documented wrapper macros are provided to
enforce the use of ACQUIRE() or guard() semantics and avoid the
problematic scoped guard.
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
include/linux/iio/iio.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 65 insertions(+)
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index fa671e120e95..4a0a77fcfa8d 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -10,6 +10,7 @@
#include <linux/align.h>
#include <linux/device.h>
#include <linux/cdev.h>
+#include <linux/cleanup.h>
#include <linux/compiler_types.h>
#include <linux/minmax.h>
#include <linux/slab.h>
@@ -740,6 +741,70 @@ static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev)
*/
#define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev)
+/*
+ * These classes are not meant to be used directly by drivers (hence the
+ * __priv__ prefix). Instead, documented wrapper macros are provided below to
+ * enforce the use of ACQUIRE() or guard() semantics and avoid the problematic
+ * scoped guard variants.
+ */
+DEFINE_GUARD(__priv__iio_dev_mode_lock, struct iio_dev *,
+ __iio_dev_mode_lock(_T), __iio_dev_mode_unlock(_T));
+DEFINE_GUARD_COND(__priv__iio_dev_mode_lock, _try_direct,
+ iio_device_claim_direct(_T));
+
+/**
+ * IIO_DEV_ACQUIRE_DIRECT_MODE(dev, var) - Tries to acquire the direct mode
+ * lock with automatic release
+ * @dev: IIO device instance
+ * @claim: Variable identifier to store acquire result
+ *
+ * Tries to acquire the direct mode lock with cleanup ACQUIRE() semantics and
+ * automatically releases it at the end of the scope. It most be always paired
+ * with IIO_DEV_ACQUIRE_ERR(), for example (notice the scope braces)::
+ *
+ * switch() {
+ * case IIO_CHAN_INFO_RAW: {
+ * IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ * if (IIO_DEV_ACQUIRE_FAILED(claim))
+ * return -EBUSY;
+ *
+ * ...
+ * }
+ * case IIO_CHAN_INFO_SCALE:
+ * ...
+ * ...
+ * }
+ *
+ * Context: Can sleep
+ */
+#define IIO_DEV_ACQUIRE_DIRECT_MODE(dev, claim) \
+ ACQUIRE(__priv__iio_dev_mode_lock_try_direct, claim)(dev)
+
+/**
+ * IIO_DEV_ACQUIRE_FAILED() - ACQUIRE_ERR() wrapper
+ * @claim: The claim variable passed to IIO_DEV_ACQUIRE_*_MODE()
+ *
+ * Return: true if failed to acquire the mode, otherwise false.
+ */
+#define IIO_DEV_ACQUIRE_FAILED(claim) \
+ ACQUIRE_ERR(__priv__iio_dev_mode_lock_try_direct, &(claim))
+
+/**
+ * IIO_DEV_GUARD_CURRENT_MODE - Acquires the mode lock with automatic release
+ * @dev: IIO device instance
+ *
+ * Acquires the mode lock with cleanup guard() semantics. It is usually paired
+ * with iio_buffer_enabled().
+ *
+ * This should *not* be used to protect internal driver state and it's use in
+ * general is *strongly* discouraged. Use any of the IIO_DEV_ACQUIRE_*_MODE()
+ * variants.
+ *
+ * Context: Can sleep
+ */
+#define IIO_DEV_GUARD_CURRENT_MODE(dev) \
+ guard(__priv__iio_dev_mode_lock)(dev)
+
extern const struct bus_type iio_bus_type;
/**
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 5/7] iio: light: vcnl4000: Use IIO cleanup helpers
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
` (3 preceding siblings ...)
2026-01-18 15:44 ` [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*() Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 6/7] iio: health: max30102: " Kurt Borja
2026-01-18 15:44 ` [PATCH v4 7/7] iio: light: opt4060: " Kurt Borja
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Use IIO_DEV_ACQUIRE_DIRECT_MODE() helper to automatically release direct
mode.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/light/vcnl4000.c | 49 ++++++++++++++++----------------------------
1 file changed, 18 insertions(+), 31 deletions(-)
diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index 4dbb2294a843..a36c23813679 100644
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -1078,20 +1078,17 @@ static int vcnl4010_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
- case IIO_CHAN_INFO_SCALE:
- if (!iio_device_claim_direct(indio_dev))
+ case IIO_CHAN_INFO_SCALE: {
+ IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ if (IIO_DEV_ACQUIRE_FAILED(claim))
return -EBUSY;
/* Protect against event capture. */
- if (vcnl4010_is_in_periodic_mode(data)) {
- ret = -EBUSY;
- } else {
- ret = vcnl4000_read_raw(indio_dev, chan, val, val2,
- mask);
- }
+ if (vcnl4010_is_in_periodic_mode(data))
+ return -EBUSY;
- iio_device_release_direct(indio_dev);
- return ret;
+ return vcnl4000_read_raw(indio_dev, chan, val, val2, mask);
+ }
case IIO_CHAN_INFO_SAMP_FREQ:
switch (chan->type) {
case IIO_PROXIMITY:
@@ -1148,36 +1145,27 @@ static int vcnl4010_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
- int ret;
struct vcnl4000_data *data = iio_priv(indio_dev);
- if (!iio_device_claim_direct(indio_dev))
+ IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ if (IIO_DEV_ACQUIRE_FAILED(claim))
return -EBUSY;
/* Protect against event capture. */
- if (vcnl4010_is_in_periodic_mode(data)) {
- ret = -EBUSY;
- goto end;
- }
+ if (vcnl4010_is_in_periodic_mode(data))
+ return -EBUSY;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
switch (chan->type) {
case IIO_PROXIMITY:
- ret = vcnl4010_write_proxy_samp_freq(data, val, val2);
- goto end;
+ return vcnl4010_write_proxy_samp_freq(data, val, val2);
default:
- ret = -EINVAL;
- goto end;
+ return -EINVAL;
}
default:
- ret = -EINVAL;
- goto end;
+ return -EINVAL;
}
-
-end:
- iio_device_release_direct(indio_dev);
- return ret;
}
static int vcnl4010_read_event(struct iio_dev *indio_dev,
@@ -1438,14 +1426,13 @@ static int vcnl4010_config_threshold_disable(struct vcnl4000_data *data)
static int vcnl4010_config_threshold(struct iio_dev *indio_dev, bool state)
{
struct vcnl4000_data *data = iio_priv(indio_dev);
- int ret;
if (state) {
- if (!iio_device_claim_direct(indio_dev))
+ IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ if (IIO_DEV_ACQUIRE_FAILED(claim))
return -EBUSY;
- ret = vcnl4010_config_threshold_enable(data);
- iio_device_release_direct(indio_dev);
- return ret;
+
+ return vcnl4010_config_threshold_enable(data);
} else {
return vcnl4010_config_threshold_disable(data);
}
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 6/7] iio: health: max30102: Use IIO cleanup helpers
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
` (4 preceding siblings ...)
2026-01-18 15:44 ` [PATCH v4 5/7] iio: light: vcnl4000: Use IIO cleanup helpers Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 7/7] iio: light: opt4060: " Kurt Borja
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Use IIO_DEV_GUARD_CURRENT_MODE() cleanup helper to simplify and drop
busy-waiting code in max30102_read_raw().
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/health/max30102.c | 33 +++++++++------------------------
1 file changed, 9 insertions(+), 24 deletions(-)
diff --git a/drivers/iio/health/max30102.c b/drivers/iio/health/max30102.c
index 6918fcb5de2b..47da44efd68b 100644
--- a/drivers/iio/health/max30102.c
+++ b/drivers/iio/health/max30102.c
@@ -467,44 +467,29 @@ static int max30102_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct max30102_data *data = iio_priv(indio_dev);
- int ret = -EINVAL;
+ int ret;
switch (mask) {
- case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_RAW: {
/*
* Temperature reading can only be acquired when not in
* shutdown; leave shutdown briefly when buffer not running
*/
-any_mode_retry:
- if (!iio_device_try_claim_buffer_mode(indio_dev)) {
- /*
- * This one is a *bit* hacky. If we cannot claim buffer
- * mode, then try direct mode so that we make sure
- * things cannot concurrently change. And we just keep
- * trying until we get one of the modes...
- */
- if (!iio_device_claim_direct(indio_dev))
- goto any_mode_retry;
+ IIO_DEV_GUARD_CURRENT_MODE(indio_dev);
- ret = max30102_get_temp(data, val, true);
- iio_device_release_direct(indio_dev);
- } else {
- ret = max30102_get_temp(data, val, false);
- iio_device_release_buffer_mode(indio_dev);
- }
+ ret = max30102_get_temp(data, val, !iio_buffer_enabled(indio_dev));
if (ret)
return ret;
- ret = IIO_VAL_INT;
- break;
+ return IIO_VAL_INT;
+ }
case IIO_CHAN_INFO_SCALE:
*val = 1000; /* 62.5 */
*val2 = 16;
- ret = IIO_VAL_FRACTIONAL;
- break;
+ return IIO_VAL_FRACTIONAL;
+ default:
+ return -EINVAL;
}
-
- return ret;
}
static const struct iio_info max30102_info = {
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v4 7/7] iio: light: opt4060: Use IIO cleanup helpers
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
` (5 preceding siblings ...)
2026-01-18 15:44 ` [PATCH v4 6/7] iio: health: max30102: " Kurt Borja
@ 2026-01-18 15:44 ` Kurt Borja
6 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-18 15:44 UTC (permalink / raw)
To: Andy Shevchenko, Lars-Peter Clausen, Michael Hennerich,
Jonathan Cameron, Benson Leung, Antoniu Miclaus, Gwendal Grignou,
Shrikant Raskar, Per-Daniel Olsson
Cc: David Lechner, Nuno Sá, Andy Shevchenko, Guenter Roeck,
Jonathan Cameron, linux-iio, linux-kernel, chrome-platform,
Kurt Borja
Use IIO_DEV_GUARD_CURRENT_MODE() cleanup helper to simplify and drop
busy-waiting code in opt4060_set_driver_state().
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
drivers/iio/light/opt4060.c | 52 +++++++++++++++------------------------------
1 file changed, 17 insertions(+), 35 deletions(-)
diff --git a/drivers/iio/light/opt4060.c b/drivers/iio/light/opt4060.c
index 8c4a1f562a83..d6e915ab355d 100644
--- a/drivers/iio/light/opt4060.c
+++ b/drivers/iio/light/opt4060.c
@@ -302,41 +302,23 @@ static int opt4060_set_driver_state(struct iio_dev *indio_dev,
bool continuous_irq)
{
struct opt4060_chip *chip = iio_priv(indio_dev);
- int ret = 0;
-any_mode_retry:
- if (!iio_device_try_claim_buffer_mode(indio_dev)) {
- /*
- * This one is a *bit* hacky. If we cannot claim buffer mode,
- * then try direct mode so that we make sure things cannot
- * concurrently change. And we just keep trying until we get one
- * of the modes...
- */
- if (!iio_device_claim_direct(indio_dev))
- goto any_mode_retry;
- /*
- * This path means that we managed to claim direct mode. In
- * this case the buffer isn't enabled and it's okay to leave
- * continuous mode for sampling and/or irq.
- */
- ret = opt4060_set_state_common(chip, continuous_sampling,
- continuous_irq);
- iio_device_release_direct(indio_dev);
- return ret;
- } else {
- /*
- * This path means that we managed to claim buffer mode. In
- * this case the buffer is enabled and irq and sampling must go
- * to or remain continuous, but only if the trigger is from this
- * device.
- */
- if (!iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
- ret = opt4060_set_state_common(chip, true, true);
- else
- ret = opt4060_set_state_common(chip, continuous_sampling,
- continuous_irq);
- iio_device_release_buffer_mode(indio_dev);
- }
- return ret;
+
+ IIO_DEV_GUARD_CURRENT_MODE(indio_dev);
+
+ /*
+ * If we manage to claim buffer mode and we are using our own trigger,
+ * IRQ and sampling must go to or remain continuous.
+ */
+ if (iio_buffer_enabled(indio_dev) &&
+ iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
+ return opt4060_set_state_common(chip, true, true);
+
+ /*
+ * This path means that we managed to claim direct mode. In this case
+ * the buffer isn't enabled and it's okay to leave continuous mode for
+ * sampling and/or irq.
+ */
+ return opt4060_set_state_common(chip, continuous_sampling, continuous_irq);
}
/*
--
2.52.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()
2026-01-18 15:44 ` [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*() Kurt Borja
@ 2026-01-18 19:35 ` David Lechner
2026-01-19 19:30 ` Kurt Borja
2026-01-19 8:15 ` Andy Shevchenko
1 sibling, 1 reply; 12+ messages in thread
From: David Lechner @ 2026-01-18 19:35 UTC (permalink / raw)
To: Kurt Borja, Andy Shevchenko, Lars-Peter Clausen,
Michael Hennerich, Jonathan Cameron, Benson Leung,
Antoniu Miclaus, Gwendal Grignou, Shrikant Raskar,
Per-Daniel Olsson
Cc: Nuno Sá, Andy Shevchenko, Guenter Roeck, Jonathan Cameron,
linux-iio, linux-kernel, chrome-platform
On 1/18/26 9:44 AM, Kurt Borja wrote:
> Add guard classes for iio_device_claim_*() conditional locks. This will
> aid drivers write safer and cleaner code when dealing with some common
> patterns.
>
> These classes are not meant to be used directly by drivers (hence the
> __priv__ prefix). Instead, documented wrapper macros are provided to
> enforce the use of ACQUIRE() or guard() semantics and avoid the
> problematic scoped guard.
>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> Reviewed-by: David Lechner <dlechner@baylibre.com>
> Reviewed-by: Nuno Sá <nuno.sa@analog.com>
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
> include/linux/iio/iio.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 65 insertions(+)
>
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index fa671e120e95..4a0a77fcfa8d 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -10,6 +10,7 @@
> #include <linux/align.h>
> #include <linux/device.h>
> #include <linux/cdev.h>
> +#include <linux/cleanup.h>
> #include <linux/compiler_types.h>
> #include <linux/minmax.h>
> #include <linux/slab.h>
> @@ -740,6 +741,70 @@ static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev)
> */
> #define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev)
>
> +/*
> + * These classes are not meant to be used directly by drivers (hence the
> + * __priv__ prefix). Instead, documented wrapper macros are provided below to
> + * enforce the use of ACQUIRE() or guard() semantics and avoid the problematic
> + * scoped guard variants.
> + */
> +DEFINE_GUARD(__priv__iio_dev_mode_lock, struct iio_dev *,
> + __iio_dev_mode_lock(_T), __iio_dev_mode_unlock(_T));
> +DEFINE_GUARD_COND(__priv__iio_dev_mode_lock, _try_direct,
> + iio_device_claim_direct(_T));
> +
> +/**
> + * IIO_DEV_ACQUIRE_DIRECT_MODE(dev, var) - Tries to acquire the direct mode
> + * lock with automatic release
Should be just IIO_DEV_ACQUIRE_DIRECT_MODE()
> + * @dev: IIO device instance
> + * @claim: Variable identifier to store acquire result
> + *
> + * Tries to acquire the direct mode lock with cleanup ACQUIRE() semantics and
> + * automatically releases it at the end of the scope. It most be always paired
> + * with IIO_DEV_ACQUIRE_ERR(), for example (notice the scope braces)::
> + *
> + * switch() {
> + * case IIO_CHAN_INFO_RAW: {
> + * IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
> + * if (IIO_DEV_ACQUIRE_FAILED(claim))
> + * return -EBUSY;
> + *
> + * ...
> + * }
> + * case IIO_CHAN_INFO_SCALE:
> + * ...
> + * ...
> + * }
> + *
> + * Context: Can sleep
> + */
> +#define IIO_DEV_ACQUIRE_DIRECT_MODE(dev, claim) \
> + ACQUIRE(__priv__iio_dev_mode_lock_try_direct, claim)(dev)
> +
> +/**
> + * IIO_DEV_ACQUIRE_FAILED() - ACQUIRE_ERR() wrapper
This one is correct style.
> + * @claim: The claim variable passed to IIO_DEV_ACQUIRE_*_MODE()
> + *
> + * Return: true if failed to acquire the mode, otherwise false.
> + */
> +#define IIO_DEV_ACQUIRE_FAILED(claim) \
> + ACQUIRE_ERR(__priv__iio_dev_mode_lock_try_direct, &(claim))
> +
> +/**
> + * IIO_DEV_GUARD_CURRENT_MODE - Acquires the mode lock with automatic release
Missing ()
> + * @dev: IIO device instance
> + *
> + * Acquires the mode lock with cleanup guard() semantics. It is usually paired
> + * with iio_buffer_enabled().
> + *
> + * This should *not* be used to protect internal driver state and it's use in
> + * general is *strongly* discouraged. Use any of the IIO_DEV_ACQUIRE_*_MODE()
> + * variants.
> + *
> + * Context: Can sleep
> + */
> +#define IIO_DEV_GUARD_CURRENT_MODE(dev) \
> + guard(__priv__iio_dev_mode_lock)(dev)
> +
> extern const struct bus_type iio_bus_type;
>
> /**
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()
2026-01-18 15:44 ` [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*() Kurt Borja
2026-01-18 19:35 ` David Lechner
@ 2026-01-19 8:15 ` Andy Shevchenko
2026-01-19 19:31 ` Kurt Borja
1 sibling, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2026-01-19 8:15 UTC (permalink / raw)
To: Kurt Borja
Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
Benson Leung, Antoniu Miclaus, Gwendal Grignou, Shrikant Raskar,
Per-Daniel Olsson, David Lechner, Nuno Sá, Andy Shevchenko,
Guenter Roeck, Jonathan Cameron, linux-iio, linux-kernel,
chrome-platform
On Sun, Jan 18, 2026 at 10:44:31AM -0500, Kurt Borja wrote:
> Add guard classes for iio_device_claim_*() conditional locks. This will
> aid drivers write safer and cleaner code when dealing with some common
> patterns.
>
> These classes are not meant to be used directly by drivers (hence the
> __priv__ prefix). Instead, documented wrapper macros are provided to
> enforce the use of ACQUIRE() or guard() semantics and avoid the
> problematic scoped guard.
Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()
2026-01-18 19:35 ` David Lechner
@ 2026-01-19 19:30 ` Kurt Borja
0 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-19 19:30 UTC (permalink / raw)
To: David Lechner, Kurt Borja, Andy Shevchenko, Lars-Peter Clausen,
Michael Hennerich, Jonathan Cameron, Benson Leung,
Antoniu Miclaus, Gwendal Grignou, Shrikant Raskar,
Per-Daniel Olsson
Cc: Nuno Sá, Andy Shevchenko, Guenter Roeck, Jonathan Cameron,
linux-iio, linux-kernel, chrome-platform
On Sun Jan 18, 2026 at 2:35 PM -05, David Lechner wrote:
> On 1/18/26 9:44 AM, Kurt Borja wrote:
>> Add guard classes for iio_device_claim_*() conditional locks. This will
>> aid drivers write safer and cleaner code when dealing with some common
>> patterns.
>>
>> These classes are not meant to be used directly by drivers (hence the
>> __priv__ prefix). Instead, documented wrapper macros are provided to
>> enforce the use of ACQUIRE() or guard() semantics and avoid the
>> problematic scoped guard.
>>
>> Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
>> Reviewed-by: David Lechner <dlechner@baylibre.com>
>> Reviewed-by: Nuno Sá <nuno.sa@analog.com>
>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>> ---
>> include/linux/iio/iio.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 65 insertions(+)
>>
>> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
>> index fa671e120e95..4a0a77fcfa8d 100644
>> --- a/include/linux/iio/iio.h
>> +++ b/include/linux/iio/iio.h
>> @@ -10,6 +10,7 @@
>> #include <linux/align.h>
>> #include <linux/device.h>
>> #include <linux/cdev.h>
>> +#include <linux/cleanup.h>
>> #include <linux/compiler_types.h>
>> #include <linux/minmax.h>
>> #include <linux/slab.h>
>> @@ -740,6 +741,70 @@ static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev)
>> */
>> #define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev)
>>
>> +/*
>> + * These classes are not meant to be used directly by drivers (hence the
>> + * __priv__ prefix). Instead, documented wrapper macros are provided below to
>> + * enforce the use of ACQUIRE() or guard() semantics and avoid the problematic
>> + * scoped guard variants.
>> + */
>> +DEFINE_GUARD(__priv__iio_dev_mode_lock, struct iio_dev *,
>> + __iio_dev_mode_lock(_T), __iio_dev_mode_unlock(_T));
>> +DEFINE_GUARD_COND(__priv__iio_dev_mode_lock, _try_direct,
>> + iio_device_claim_direct(_T));
>> +
>> +/**
>> + * IIO_DEV_ACQUIRE_DIRECT_MODE(dev, var) - Tries to acquire the direct mode
>> + * lock with automatic release
>
> Should be just IIO_DEV_ACQUIRE_DIRECT_MODE()
>
>> + * @dev: IIO device instance
>> + * @claim: Variable identifier to store acquire result
>> + *
>> + * Tries to acquire the direct mode lock with cleanup ACQUIRE() semantics and
>> + * automatically releases it at the end of the scope. It most be always paired
>> + * with IIO_DEV_ACQUIRE_ERR(), for example (notice the scope braces)::
>> + *
>> + * switch() {
>> + * case IIO_CHAN_INFO_RAW: {
>> + * IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
>> + * if (IIO_DEV_ACQUIRE_FAILED(claim))
>> + * return -EBUSY;
>> + *
>> + * ...
>> + * }
>> + * case IIO_CHAN_INFO_SCALE:
>> + * ...
>> + * ...
>> + * }
>> + *
>> + * Context: Can sleep
>> + */
>> +#define IIO_DEV_ACQUIRE_DIRECT_MODE(dev, claim) \
>> + ACQUIRE(__priv__iio_dev_mode_lock_try_direct, claim)(dev)
>> +
>> +/**
>> + * IIO_DEV_ACQUIRE_FAILED() - ACQUIRE_ERR() wrapper
>
> This one is correct style.
>
>> + * @claim: The claim variable passed to IIO_DEV_ACQUIRE_*_MODE()
>> + *
>> + * Return: true if failed to acquire the mode, otherwise false.
>> + */
>> +#define IIO_DEV_ACQUIRE_FAILED(claim) \
>> + ACQUIRE_ERR(__priv__iio_dev_mode_lock_try_direct, &(claim))
>> +
>> +/**
>> + * IIO_DEV_GUARD_CURRENT_MODE - Acquires the mode lock with automatic release
>
> Missing ()
Hi David,
I didn't see what you meant in the previous email. Sorry! I'll correct
it.
--
Thanks,
~ Kurt
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()
2026-01-19 8:15 ` Andy Shevchenko
@ 2026-01-19 19:31 ` Kurt Borja
0 siblings, 0 replies; 12+ messages in thread
From: Kurt Borja @ 2026-01-19 19:31 UTC (permalink / raw)
To: Andy Shevchenko, Kurt Borja
Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
Benson Leung, Antoniu Miclaus, Gwendal Grignou, Shrikant Raskar,
Per-Daniel Olsson, David Lechner, Nuno Sá, Andy Shevchenko,
Guenter Roeck, Jonathan Cameron, linux-iio, linux-kernel,
chrome-platform
On Mon Jan 19, 2026 at 3:15 AM -05, Andy Shevchenko wrote:
> On Sun, Jan 18, 2026 at 10:44:31AM -0500, Kurt Borja wrote:
>> Add guard classes for iio_device_claim_*() conditional locks. This will
>> aid drivers write safer and cleaner code when dealing with some common
>> patterns.
>>
>> These classes are not meant to be used directly by drivers (hence the
>> __priv__ prefix). Instead, documented wrapper macros are provided to
>> enforce the use of ACQUIRE() or guard() semantics and avoid the
>> problematic scoped guard.
>
> Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Hi Andy,
Thank you for your feedback!
--
Thanks,
~ Kurt
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2026-01-19 19:31 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-01-18 15:44 [PATCH v4 0/7] iio: core: Introduce cleanup.h support for mode locks Kurt Borja
2026-01-18 15:44 ` [PATCH v4 1/7] iio: core: Add and export __iio_dev_mode_lock() Kurt Borja
2026-01-18 15:44 ` [PATCH v4 2/7] iio: core: Refactor iio_device_claim_direct() implementation Kurt Borja
2026-01-18 15:44 ` [PATCH v4 3/7] iio: core: Match iio_device_claim_*() semantics and implementation Kurt Borja
2026-01-18 15:44 ` [PATCH v4 4/7] iio: core: Add cleanup.h support for iio_device_claim_*() Kurt Borja
2026-01-18 19:35 ` David Lechner
2026-01-19 19:30 ` Kurt Borja
2026-01-19 8:15 ` Andy Shevchenko
2026-01-19 19:31 ` Kurt Borja
2026-01-18 15:44 ` [PATCH v4 5/7] iio: light: vcnl4000: Use IIO cleanup helpers Kurt Borja
2026-01-18 15:44 ` [PATCH v4 6/7] iio: health: max30102: " Kurt Borja
2026-01-18 15:44 ` [PATCH v4 7/7] iio: light: opt4060: " Kurt Borja
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