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-rw-r--r--drivers/iio/buffer_cb.c21
-rw-r--r--drivers/iio/industrialio-buffer.c66
-rw-r--r--drivers/iio/industrialio-core.c3
-rw-r--r--drivers/iio/industrialio-triggered-buffer.c7
-rw-r--r--drivers/iio/kfifo_buf.c8
-rw-r--r--drivers/staging/iio/accel/lis3l02dq_ring.c2
-rw-r--r--drivers/staging/iio/accel/sca3000_ring.c13
-rw-r--r--drivers/staging/iio/iio_simple_dummy_buffer.c2
-rw-r--r--drivers/staging/iio/impedance-analyzer/ad5933.c8
-rw-r--r--drivers/staging/iio/meter/ade7758_ring.c7
-rw-r--r--include/linux/iio/buffer.h28
11 files changed, 141 insertions, 24 deletions
diff --git a/drivers/iio/buffer_cb.c b/drivers/iio/buffer_cb.c
index 841fec1e78b2..2d9c6f8c06db 100644
--- a/drivers/iio/buffer_cb.c
+++ b/drivers/iio/buffer_cb.c
@@ -12,17 +12,27 @@ struct iio_cb_buffer {
struct iio_channel *channels;
};
-static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
+static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
{
- struct iio_cb_buffer *cb_buff = container_of(buffer,
- struct iio_cb_buffer,
- buffer);
+ return container_of(buffer, struct iio_cb_buffer, buffer);
+}
+static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
+{
+ struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
return cb_buff->cb(data, cb_buff->private);
}
+static void iio_buffer_cb_release(struct iio_buffer *buffer)
+{
+ struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
+ kfree(cb_buff->buffer.scan_mask);
+ kfree(cb_buff);
+}
+
static const struct iio_buffer_access_funcs iio_cb_access = {
.store_to = &iio_buffer_cb_store_to,
+ .release = &iio_buffer_cb_release,
};
struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
@@ -104,9 +114,8 @@ EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
{
- kfree(cb_buff->buffer.scan_mask);
iio_channel_release_all(cb_buff->channels);
- kfree(cb_buff);
+ iio_buffer_put(&cb_buff->buffer);
}
EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index e9f389b9da69..36c39dcad850 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -74,6 +74,7 @@ void iio_buffer_init(struct iio_buffer *buffer)
INIT_LIST_HEAD(&buffer->demux_list);
INIT_LIST_HEAD(&buffer->buffer_list);
init_waitqueue_head(&buffer->pollq);
+ kref_init(&buffer->ref);
}
EXPORT_SYMBOL(iio_buffer_init);
@@ -454,6 +455,19 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
return bytes;
}
+static void iio_buffer_activate(struct iio_dev *indio_dev,
+ struct iio_buffer *buffer)
+{
+ iio_buffer_get(buffer);
+ list_add(&buffer->buffer_list, &indio_dev->buffer_list);
+}
+
+static void iio_buffer_deactivate(struct iio_buffer *buffer)
+{
+ list_del_init(&buffer->buffer_list);
+ iio_buffer_put(buffer);
+}
+
void iio_disable_all_buffers(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer, *_buffer;
@@ -466,7 +480,7 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev)
list_for_each_entry_safe(buffer, _buffer,
&indio_dev->buffer_list, buffer_list)
- list_del_init(&buffer->buffer_list);
+ iio_buffer_deactivate(buffer);
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
@@ -503,9 +517,9 @@ int iio_update_buffers(struct iio_dev *indio_dev,
indio_dev->active_scan_mask = NULL;
if (remove_buffer)
- list_del_init(&remove_buffer->buffer_list);
+ iio_buffer_deactivate(remove_buffer);
if (insert_buffer)
- list_add(&insert_buffer->buffer_list, &indio_dev->buffer_list);
+ iio_buffer_activate(indio_dev, insert_buffer);
/* If no buffers in list, we are done */
if (list_empty(&indio_dev->buffer_list)) {
@@ -540,7 +554,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
* Roll back.
* Note can only occur when adding a buffer.
*/
- list_del_init(&insert_buffer->buffer_list);
+ iio_buffer_deactivate(insert_buffer);
if (old_mask) {
indio_dev->active_scan_mask = old_mask;
success = -EINVAL;
@@ -631,7 +645,7 @@ error_run_postdisable:
error_remove_inserted:
if (insert_buffer)
- list_del_init(&insert_buffer->buffer_list);
+ iio_buffer_deactivate(insert_buffer);
indio_dev->active_scan_mask = old_mask;
kfree(compound_mask);
error_ret:
@@ -952,3 +966,45 @@ error_clear_mux_table:
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_demux);
+
+/**
+ * iio_buffer_release() - Free a buffer's resources
+ * @ref: Pointer to the kref embedded in the iio_buffer struct
+ *
+ * This function is called when the last reference to the buffer has been
+ * dropped. It will typically free all resources allocated by the buffer. Do not
+ * call this function manually, always use iio_buffer_put() when done using a
+ * buffer.
+ */
+static void iio_buffer_release(struct kref *ref)
+{
+ struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
+
+ buffer->access->release(buffer);
+}
+
+/**
+ * iio_buffer_get() - Grab a reference to the buffer
+ * @buffer: The buffer to grab a reference for, may be NULL
+ *
+ * Returns the pointer to the buffer that was passed into the function.
+ */
+struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
+{
+ if (buffer)
+ kref_get(&buffer->ref);
+
+ return buffer;
+}
+EXPORT_SYMBOL_GPL(iio_buffer_get);
+
+/**
+ * iio_buffer_put() - Release the reference to the buffer
+ * @buffer: The buffer to release the reference for, may be NULL
+ */
+void iio_buffer_put(struct iio_buffer *buffer)
+{
+ if (buffer)
+ kref_put(&buffer->ref, iio_buffer_release);
+}
+EXPORT_SYMBOL_GPL(iio_buffer_put);
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index ecf58963ac24..f939bad31ca1 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -28,6 +28,7 @@
#include "iio_core_trigger.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
+#include <linux/iio/buffer.h>
/* IDA to assign each registered device a unique id */
static DEFINE_IDA(iio_ida);
@@ -895,6 +896,8 @@ static void iio_dev_release(struct device *device)
iio_device_unregister_eventset(indio_dev);
iio_device_unregister_sysfs(indio_dev);
+ iio_buffer_put(indio_dev->buffer);
+
ida_simple_remove(&iio_ida, indio_dev->id);
kfree(indio_dev);
}
diff --git a/drivers/iio/industrialio-triggered-buffer.c b/drivers/iio/industrialio-triggered-buffer.c
index 46c619b0d8c5..c1cb1f94fe2e 100644
--- a/drivers/iio/industrialio-triggered-buffer.c
+++ b/drivers/iio/industrialio-triggered-buffer.c
@@ -47,14 +47,17 @@ int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
irqreturn_t (*pollfunc_th)(int irq, void *p),
const struct iio_buffer_setup_ops *setup_ops)
{
+ struct iio_buffer *buffer;
int ret;
- indio_dev->buffer = iio_kfifo_allocate(indio_dev);
- if (!indio_dev->buffer) {
+ buffer = iio_kfifo_allocate(indio_dev);
+ if (!buffer) {
ret = -ENOMEM;
goto error_ret;
}
+ iio_device_attach_buffer(indio_dev, buffer);
+
indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
pollfunc_th,
IRQF_ONESHOT,
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
index 538d4616e48f..b4ac55a29fc4 100644
--- a/drivers/iio/kfifo_buf.c
+++ b/drivers/iio/kfifo_buf.c
@@ -130,6 +130,11 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r,
return copied;
}
+static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
+{
+ kfree(iio_to_kfifo(buffer));
+}
+
static const struct iio_buffer_access_funcs kfifo_access_funcs = {
.store_to = &iio_store_to_kfifo,
.read_first_n = &iio_read_first_n_kfifo,
@@ -138,6 +143,7 @@ static const struct iio_buffer_access_funcs kfifo_access_funcs = {
.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
.get_length = &iio_get_length_kfifo,
.set_length = &iio_set_length_kfifo,
+ .release = &iio_kfifo_buffer_release,
};
struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
@@ -158,7 +164,7 @@ EXPORT_SYMBOL(iio_kfifo_allocate);
void iio_kfifo_free(struct iio_buffer *r)
{
- kfree(iio_to_kfifo(r));
+ iio_buffer_put(r);
}
EXPORT_SYMBOL(iio_kfifo_free);
diff --git a/drivers/staging/iio/accel/lis3l02dq_ring.c b/drivers/staging/iio/accel/lis3l02dq_ring.c
index ed7de471e3f3..2d559ba353d2 100644
--- a/drivers/staging/iio/accel/lis3l02dq_ring.c
+++ b/drivers/staging/iio/accel/lis3l02dq_ring.c
@@ -396,7 +396,7 @@ int lis3l02dq_configure_buffer(struct iio_dev *indio_dev)
if (!buffer)
return -ENOMEM;
- indio_dev->buffer = buffer;
+ iio_device_attach_buffer(indio_dev, buffer);
buffer->scan_timestamp = true;
indio_dev->setup_ops = &lis3l02dq_buffer_setup_ops;
diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
index 0f2ee3373d9a..4a27beb1451a 100644
--- a/drivers/staging/iio/accel/sca3000_ring.c
+++ b/drivers/staging/iio/accel/sca3000_ring.c
@@ -265,7 +265,7 @@ static struct iio_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev)
return buf;
}
-static inline void sca3000_rb_free(struct iio_buffer *r)
+static void sca3000_ring_release(struct iio_buffer *r)
{
kfree(iio_to_hw_buf(r));
}
@@ -274,23 +274,28 @@ static const struct iio_buffer_access_funcs sca3000_ring_access_funcs = {
.read_first_n = &sca3000_read_first_n_hw_rb,
.get_length = &sca3000_ring_get_length,
.get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum,
+ .release = sca3000_ring_release,
};
int sca3000_configure_ring(struct iio_dev *indio_dev)
{
- indio_dev->buffer = sca3000_rb_allocate(indio_dev);
- if (indio_dev->buffer == NULL)
+ struct iio_buffer *buffer;
+
+ buffer = sca3000_rb_allocate(indio_dev);
+ if (buffer == NULL)
return -ENOMEM;
indio_dev->modes |= INDIO_BUFFER_HARDWARE;
indio_dev->buffer->access = &sca3000_ring_access_funcs;
+ iio_device_attach_buffer(indio_dev, buffer);
+
return 0;
}
void sca3000_unconfigure_ring(struct iio_dev *indio_dev)
{
- sca3000_rb_free(indio_dev->buffer);
+ iio_buffer_put(indio_dev->buffer);
}
static inline
diff --git a/drivers/staging/iio/iio_simple_dummy_buffer.c b/drivers/staging/iio/iio_simple_dummy_buffer.c
index 09c93ac7351a..2612e87fbcb4 100644
--- a/drivers/staging/iio/iio_simple_dummy_buffer.c
+++ b/drivers/staging/iio/iio_simple_dummy_buffer.c
@@ -135,7 +135,7 @@ int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev,
goto error_ret;
}
- indio_dev->buffer = buffer;
+ iio_device_attach_buffer(indio_dev, buffer);
/* Enable timestamps by default */
buffer->scan_timestamp = true;
diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
index 712f3c22ce64..f5701159bf36 100644
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -630,10 +630,14 @@ static const struct iio_buffer_setup_ops ad5933_ring_setup_ops = {
static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
- indio_dev->buffer = iio_kfifo_allocate(indio_dev);
- if (!indio_dev->buffer)
+ struct iio_buffer *buffer;
+
+ buffer = iio_kfifo_allocate(indio_dev);
+ if (buffer)
return -ENOMEM;
+ iio_device_attach_buffer(indio_dev, buffer);
+
/* Ring buffer functions - here trigger setup related */
indio_dev->setup_ops = &ad5933_ring_setup_ops;
diff --git a/drivers/staging/iio/meter/ade7758_ring.c b/drivers/staging/iio/meter/ade7758_ring.c
index 4080995c99b6..7a448ffaeb14 100644
--- a/drivers/staging/iio/meter/ade7758_ring.c
+++ b/drivers/staging/iio/meter/ade7758_ring.c
@@ -121,14 +121,17 @@ void ade7758_unconfigure_ring(struct iio_dev *indio_dev)
int ade7758_configure_ring(struct iio_dev *indio_dev)
{
struct ade7758_state *st = iio_priv(indio_dev);
+ struct iio_buffer *buffer;
int ret = 0;
- indio_dev->buffer = iio_kfifo_allocate(indio_dev);
- if (!indio_dev->buffer) {
+ buffer = iio_kfifo_allocate(indio_dev);
+ if (!buffer) {
ret = -ENOMEM;
return ret;
}
+ iio_device_attach_buffer(indio_dev, buffer);
+
indio_dev->setup_ops = &ade7758_ring_setup_ops;
indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
index a1124bdc4cac..6e428d96d570 100644
--- a/include/linux/iio/buffer.h
+++ b/include/linux/iio/buffer.h
@@ -11,6 +11,7 @@
#define _IIO_BUFFER_GENERIC_H_
#include <linux/sysfs.h>
#include <linux/iio/iio.h>
+#include <linux/kref.h>
#ifdef CONFIG_IIO_BUFFER
@@ -26,6 +27,8 @@ struct iio_buffer;
* @set_bytes_per_datum:set number of bytes per datum
* @get_length: get number of datums in buffer
* @set_length: set number of datums in buffer
+ * @release: called when the last reference to the buffer is dropped,
+ * should free all resources allocated by the buffer.
*
* The purpose of this structure is to make the buffer element
* modular as event for a given driver, different usecases may require
@@ -47,6 +50,8 @@ struct iio_buffer_access_funcs {
int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);
int (*get_length)(struct iio_buffer *buffer);
int (*set_length)(struct iio_buffer *buffer, int length);
+
+ void (*release)(struct iio_buffer *buffer);
};
/**
@@ -67,6 +72,7 @@ struct iio_buffer_access_funcs {
* @demux_list: [INTERN] list of operations required to demux the scan.
* @demux_bounce: [INTERN] buffer for doing gather from incoming scan.
* @buffer_list: [INTERN] entry in the devices list of current buffers.
+ * @ref: [INTERN] reference count of the buffer.
*/
struct iio_buffer {
int length;
@@ -83,6 +89,7 @@ struct iio_buffer {
struct list_head demux_list;
void *demux_bounce;
struct list_head buffer_list;
+ struct kref ref;
};
/**
@@ -204,6 +211,24 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev);
bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
const unsigned long *mask);
+struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer);
+void iio_buffer_put(struct iio_buffer *buffer);
+
+/**
+ * iio_device_attach_buffer - Attach a buffer to a IIO device
+ * @indio_dev: The device the buffer should be attached to
+ * @buffer: The buffer to attach to the device
+ *
+ * This function attaches a buffer to a IIO device. The buffer stays attached to
+ * the device until the device is freed. The function should only be called at
+ * most once per device.
+ */
+static inline void iio_device_attach_buffer(struct iio_dev *indio_dev,
+ struct iio_buffer *buffer)
+{
+ indio_dev->buffer = iio_buffer_get(buffer);
+}
+
#else /* CONFIG_IIO_BUFFER */
static inline int iio_buffer_register(struct iio_dev *indio_dev,
@@ -216,6 +241,9 @@ static inline int iio_buffer_register(struct iio_dev *indio_dev,
static inline void iio_buffer_unregister(struct iio_dev *indio_dev)
{}
+static inline void iio_buffer_get(struct iio_buffer *buffer) {}
+static inline void iio_buffer_put(struct iio_buffer *buffer) {}
+
#endif /* CONFIG_IIO_BUFFER */
#endif /* _IIO_BUFFER_GENERIC_H_ */