Merge tag 'staging-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver update from Greg KH:
 "Here's the big drivers/staging/ update for 3.13-rc1.

  Nothing major here, just a _ton_ of fixes and cleanups, mostly driven
  by the new round of OPW applicants, but also there are lots of other
  people doing staging tree cleanups these days in order to help get the
  drivers into mergable shape.

  We also merge, and then revert, the ktap code, as Ingo and the other
  perf/ftrace developers feel it should go into the "real" part of the
  kernel with only a bit more work, so no need to put it in staging for
  now.

  All of this has been in linux-next for a while with no reported
  issues"

* tag 'staging-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1045 commits)
  staging: drm/imx: fix return value check in ipu_add_subdevice_pdata()
  Staging: zram: Fix access of NULL pointer
  Staging: zram: Fix variable dereferenced before check
  Staging: rtl8187se: space prohibited before semicolon in r8185b_init.c
  Staging: rtl8187se: fix space prohibited after that open parenthesis '(' in r8185b_init.c
  Staging: rtl8187se: fix braces {} are not necessary for single statement blocks in r8185b_init.c
  Staging: rtl8187se: fix trailing whitespace in r8185b_init.c
  Staging: rtl8187se: fix please, no space before tabs in r8185b_init.c
  drivers/staging/nvec/Kconfig: remove trailing whitespace
  Staging: dwc2: Fix variable dereferenced before check
  Staging: xgifb: fix braces {} are not necessary for any arm of this statement
  staging: rtl8192e: remove unneeded semicolons
  staging: rtl8192e: use true and false for bool variables
  staging: ft1000: return values corrected in scram_start_dwnld
  staging: ft1000: change values of status return variable in write_dpram32_and_check
  staging: bcm: Remove unnecessary pointer casting
  imx-drm: ipuv3-crtc: Invert IPU DI0 clock polarity
  staging: r8188eu: Fix sparse warnings in rtl_p2p.c
  staging: r8188eu: Fix sparse warnings in rtw_mlme_ext.c
  staging: r8188eu: Fix sparse warnings in rtl8188e.cmd.c
  ...

1 files changed, 166 insertions, 76 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 2db7dcd826b9..7f9152c3c4d3 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -20,6 +20,7 @@
 #include <linux/cdev.h>
 #include <linux/slab.h>
 #include <linux/poll.h>
+#include <linux/sched.h>
 
 #include <linux/iio/iio.h>
 #include "iio_core.h"
@@ -31,16 +32,9 @@ static const char * const iio_endian_prefix[] = {
 	[IIO_LE] = "le",
 };
 
-static bool iio_buffer_is_active(struct iio_dev *indio_dev,
-				 struct iio_buffer *buf)
+static bool iio_buffer_is_active(struct iio_buffer *buf)
 {
-	struct list_head *p;
-
-	list_for_each(p, &indio_dev->buffer_list)
-		if (p == &buf->buffer_list)
-			return true;
-
-	return false;
+	return !list_empty(&buf->buffer_list);
 }
 
 /**
@@ -55,6 +49,9 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 	struct iio_dev *indio_dev = filp->private_data;
 	struct iio_buffer *rb = indio_dev->buffer;
 
+	if (!indio_dev->info)
+		return -ENODEV;
+
 	if (!rb || !rb->access->read_first_n)
 		return -EINVAL;
 	return rb->access->read_first_n(rb, n, buf);
@@ -69,6 +66,9 @@ unsigned int iio_buffer_poll(struct file *filp,
 	struct iio_dev *indio_dev = filp->private_data;
 	struct iio_buffer *rb = indio_dev->buffer;
 
+	if (!indio_dev->info)
+		return -ENODEV;
+
 	poll_wait(filp, &rb->pollq, wait);
 	if (rb->stufftoread)
 		return POLLIN | POLLRDNORM;
@@ -76,10 +76,27 @@ unsigned int iio_buffer_poll(struct file *filp,
 	return 0;
 }
 
+/**
+ * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
+ * @indio_dev: The IIO device
+ *
+ * Wakes up the event waitqueue used for poll(). Should usually
+ * be called when the device is unregistered.
+ */
+void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
+{
+	if (!indio_dev->buffer)
+		return;
+
+	wake_up(&indio_dev->buffer->pollq);
+}
+
 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);
 
@@ -146,7 +163,7 @@ static ssize_t iio_scan_el_store(struct device *dev,
 	if (ret < 0)
 		return ret;
 	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) {
+	if (iio_buffer_is_active(indio_dev->buffer)) {
 		ret = -EBUSY;
 		goto error_ret;
 	}
@@ -192,7 +209,7 @@ static ssize_t iio_scan_el_ts_store(struct device *dev,
 		return ret;
 
 	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) {
+	if (iio_buffer_is_active(indio_dev->buffer)) {
 		ret = -EBUSY;
 		goto error_ret;
 	}
@@ -214,7 +231,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
 				     &iio_show_scan_index,
 				     NULL,
 				     0,
-				     0,
+				     IIO_SEPARATE,
 				     &indio_dev->dev,
 				     &buffer->scan_el_dev_attr_list);
 	if (ret)
@@ -249,29 +266,14 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
 					     0,
 					     &indio_dev->dev,
 					     &buffer->scan_el_dev_attr_list);
+	if (ret)
+		goto error_ret;
 	attrcount++;
 	ret = attrcount;
 error_ret:
 	return ret;
 }
 
-static void iio_buffer_remove_and_free_scan_dev_attr(struct iio_dev *indio_dev,
-						     struct iio_dev_attr *p)
-{
-	kfree(p->dev_attr.attr.name);
-	kfree(p);
-}
-
-static void __iio_buffer_attr_cleanup(struct iio_dev *indio_dev)
-{
-	struct iio_dev_attr *p, *n;
-	struct iio_buffer *buffer = indio_dev->buffer;
-
-	list_for_each_entry_safe(p, n,
-				 &buffer->scan_el_dev_attr_list, l)
-		iio_buffer_remove_and_free_scan_dev_attr(indio_dev, p);
-}
-
 static const char * const iio_scan_elements_group_name = "scan_elements";
 
 int iio_buffer_register(struct iio_dev *indio_dev,
@@ -348,7 +350,7 @@ int iio_buffer_register(struct iio_dev *indio_dev,
 error_free_scan_mask:
 	kfree(buffer->scan_mask);
 error_cleanup_dynamic:
-	__iio_buffer_attr_cleanup(indio_dev);
+	iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
 
 	return ret;
 }
@@ -358,7 +360,7 @@ void iio_buffer_unregister(struct iio_dev *indio_dev)
 {
 	kfree(indio_dev->buffer->scan_mask);
 	kfree(indio_dev->buffer->scan_el_group.attrs);
-	__iio_buffer_attr_cleanup(indio_dev);
+	iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
 }
 EXPORT_SYMBOL(iio_buffer_unregister);
 
@@ -396,7 +398,7 @@ ssize_t iio_buffer_write_length(struct device *dev,
 			return len;
 
 	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_is_active(indio_dev, indio_dev->buffer)) {
+	if (iio_buffer_is_active(indio_dev->buffer)) {
 		ret = -EBUSY;
 	} else {
 		if (buffer->access->set_length)
@@ -414,13 +416,11 @@ ssize_t iio_buffer_show_enable(struct device *dev,
 			       char *buf)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	return sprintf(buf, "%d\n",
-		       iio_buffer_is_active(indio_dev,
-					    indio_dev->buffer));
+	return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
 }
 EXPORT_SYMBOL(iio_buffer_show_enable);
 
-/* note NULL used as error indicator as it doesn't make sense. */
+/* Note NULL used as error indicator as it doesn't make sense. */
 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
 					  unsigned int masklength,
 					  const unsigned long *mask)
@@ -435,8 +435,8 @@ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
 	return NULL;
 }
 
-static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
-				  bool timestamp)
+static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
+				const unsigned long *mask, bool timestamp)
 {
 	const struct iio_chan_spec *ch;
 	unsigned bytes = 0;
@@ -460,6 +460,19 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
 	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;
@@ -472,7 +485,7 @@ 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)
@@ -482,7 +495,21 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev)
 		kfree(indio_dev->active_scan_mask);
 }
 
-int iio_update_buffers(struct iio_dev *indio_dev,
+static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
+	struct iio_buffer *buffer)
+{
+	unsigned int bytes;
+
+	if (!buffer->access->set_bytes_per_datum)
+		return;
+
+	bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
+		buffer->scan_timestamp);
+
+	buffer->access->set_bytes_per_datum(buffer, bytes);
+}
+
+static int __iio_update_buffers(struct iio_dev *indio_dev,
 		       struct iio_buffer *insert_buffer,
 		       struct iio_buffer *remove_buffer)
 {
@@ -512,9 +539,9 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 		indio_dev->active_scan_mask = NULL;
 
 	if (remove_buffer)
-		list_del(&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)) {
@@ -524,7 +551,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 		return 0;
 	}
 
-	/* What scan mask do we actually have ?*/
+	/* What scan mask do we actually have? */
 	compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
 				sizeof(long), GFP_KERNEL);
 	if (compound_mask == NULL) {
@@ -549,7 +576,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 			 * Roll back.
 			 * Note can only occur when adding a buffer.
 			 */
-			list_del(&insert_buffer->buffer_list);
+			iio_buffer_deactivate(insert_buffer);
 			if (old_mask) {
 				indio_dev->active_scan_mask = old_mask;
 				success = -EINVAL;
@@ -579,7 +606,8 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 		iio_compute_scan_bytes(indio_dev,
 				       indio_dev->active_scan_mask,
 				       indio_dev->scan_timestamp);
-	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
+	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
+		iio_buffer_update_bytes_per_datum(indio_dev, buffer);
 		if (buffer->access->request_update) {
 			ret = buffer->access->request_update(buffer);
 			if (ret) {
@@ -588,6 +616,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 				goto error_run_postdisable;
 			}
 		}
+	}
 	if (indio_dev->info->update_scan_mode) {
 		ret = indio_dev->info
 			->update_scan_mode(indio_dev,
@@ -597,7 +626,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 			goto error_run_postdisable;
 		}
 	}
-	/* Definitely possible for devices to support both of these.*/
+	/* Definitely possible for devices to support both of these. */
 	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
 		if (!indio_dev->trig) {
 			printk(KERN_INFO "Buffer not started: no trigger\n");
@@ -608,7 +637,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 		indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
 	} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
 		indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
-	} else { /* should never be reached */
+	} else { /* Should never be reached */
 		ret = -EINVAL;
 		goto error_run_postdisable;
 	}
@@ -640,13 +669,50 @@ error_run_postdisable:
 error_remove_inserted:
 
 	if (insert_buffer)
-		list_del(&insert_buffer->buffer_list);
+		iio_buffer_deactivate(insert_buffer);
 	indio_dev->active_scan_mask = old_mask;
 	kfree(compound_mask);
 error_ret:
 
 	return ret;
 }
+
+int iio_update_buffers(struct iio_dev *indio_dev,
+		       struct iio_buffer *insert_buffer,
+		       struct iio_buffer *remove_buffer)
+{
+	int ret;
+
+	if (insert_buffer == remove_buffer)
+		return 0;
+
+	mutex_lock(&indio_dev->info_exist_lock);
+	mutex_lock(&indio_dev->mlock);
+
+	if (insert_buffer && iio_buffer_is_active(insert_buffer))
+		insert_buffer = NULL;
+
+	if (remove_buffer && !iio_buffer_is_active(remove_buffer))
+		remove_buffer = NULL;
+
+	if (!insert_buffer && !remove_buffer) {
+		ret = 0;
+		goto out_unlock;
+	}
+
+	if (indio_dev->info == NULL) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
+
+out_unlock:
+	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&indio_dev->info_exist_lock);
+
+	return ret;
+}
 EXPORT_SYMBOL_GPL(iio_update_buffers);
 
 ssize_t iio_buffer_store_enable(struct device *dev,
@@ -657,7 +723,6 @@ ssize_t iio_buffer_store_enable(struct device *dev,
 	int ret;
 	bool requested_state;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct iio_buffer *pbuf = indio_dev->buffer;
 	bool inlist;
 
 	ret = strtobool(buf, &requested_state);
@@ -667,16 +732,16 @@ ssize_t iio_buffer_store_enable(struct device *dev,
 	mutex_lock(&indio_dev->mlock);
 
 	/* Find out if it is in the list */
-	inlist = iio_buffer_is_active(indio_dev, pbuf);
+	inlist = iio_buffer_is_active(indio_dev->buffer);
 	/* Already in desired state */
 	if (inlist == requested_state)
 		goto done;
 
 	if (requested_state)
-		ret = iio_update_buffers(indio_dev,
+		ret = __iio_update_buffers(indio_dev,
 					 indio_dev->buffer, NULL);
 	else
-		ret = iio_update_buffers(indio_dev,
+		ret = __iio_update_buffers(indio_dev,
 					 NULL, indio_dev->buffer);
 
 	if (ret < 0)
@@ -687,24 +752,6 @@ done:
 }
 EXPORT_SYMBOL(iio_buffer_store_enable);
 
-int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
-{
-	struct iio_buffer *buffer;
-	unsigned bytes;
-	dev_dbg(&indio_dev->dev, "%s\n", __func__);
-
-	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
-		if (buffer->access->set_bytes_per_datum) {
-			bytes = iio_compute_scan_bytes(indio_dev,
-						       buffer->scan_mask,
-						       buffer->scan_timestamp);
-
-			buffer->access->set_bytes_per_datum(buffer, bytes);
-		}
-	return 0;
-}
-EXPORT_SYMBOL(iio_sw_buffer_preenable);
-
 /**
  * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
  * @indio_dev: the iio device
@@ -732,6 +779,7 @@ static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
 
 /**
  * iio_scan_mask_set() - set particular bit in the scan mask
+ * @indio_dev: the iio device
  * @buffer: the buffer whose scan mask we are interested in
  * @bit: the bit to be set.
  *
@@ -752,7 +800,7 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
 	if (trialmask == NULL)
 		return -ENOMEM;
 	if (!indio_dev->masklength) {
-		WARN_ON("trying to set scanmask prior to registering buffer\n");
+		WARN_ON("Trying to set scanmask prior to registering buffer\n");
 		goto err_invalid_mask;
 	}
 	bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
@@ -807,8 +855,8 @@ struct iio_demux_table {
 	struct list_head l;
 };
 
-static unsigned char *iio_demux(struct iio_buffer *buffer,
-				 unsigned char *datain)
+static const void *iio_demux(struct iio_buffer *buffer,
+				 const void *datain)
 {
 	struct iio_demux_table *t;
 
@@ -821,9 +869,9 @@ static unsigned char *iio_demux(struct iio_buffer *buffer,
 	return buffer->demux_bounce;
 }
 
-static int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data)
+static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
 {
-	unsigned char *dataout = iio_demux(buffer, data);
+	const void *dataout = iio_demux(buffer, data);
 
 	return buffer->access->store_to(buffer, dataout);
 }
@@ -838,7 +886,7 @@ static void iio_buffer_demux_free(struct iio_buffer *buffer)
 }
 
 
-int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data)
+int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
 {
 	int ret;
 	struct iio_buffer *buf;
@@ -961,3 +1009,45 @@ 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);