staging:iio: replacing term ring with buffer in the IIO core.
They aren't always ring buffers, so just use buffer for all naming.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
new file mode 100644
index 0000000..c3f57e7
--- /dev/null
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -0,0 +1,632 @@
+/* The industrial I/O core
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Handling of buffer allocation / resizing.
+ *
+ *
+ * Things to look at here.
+ * - Better memory allocation techniques?
+ * - Alternative access techniques?
+ */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+
+#include "iio.h"
+#include "iio_core.h"
+#include "sysfs.h"
+#include "buffer_generic.h"
+
+static const char * const iio_endian_prefix[] = {
+ [IIO_BE] = "be",
+ [IIO_LE] = "le",
+};
+
+/**
+ * iio_buffer_read_first_n_outer() - chrdev read for buffer access
+ *
+ * This function relies on all buffer implementations having an
+ * iio_buffer as their first element.
+ **/
+ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
+ size_t n, loff_t *f_ps)
+{
+ struct iio_dev *indio_dev = filp->private_data;
+ struct iio_buffer *rb = indio_dev->buffer;
+
+ if (!rb->access->read_first_n)
+ return -EINVAL;
+ return rb->access->read_first_n(rb, n, buf);
+}
+
+/**
+ * iio_buffer_poll() - poll the buffer to find out if it has data
+ */
+unsigned int iio_buffer_poll(struct file *filp,
+ struct poll_table_struct *wait)
+{
+ struct iio_dev *indio_dev = filp->private_data;
+ struct iio_buffer *rb = indio_dev->buffer;
+
+ poll_wait(filp, &rb->pollq, wait);
+ if (rb->stufftoread)
+ return POLLIN | POLLRDNORM;
+ /* need a way of knowing if there may be enough data... */
+ return 0;
+}
+
+void iio_chrdev_buffer_open(struct iio_dev *indio_dev)
+{
+ struct iio_buffer *rb = indio_dev->buffer;
+ if (rb && rb->access->mark_in_use)
+ rb->access->mark_in_use(rb);
+}
+
+void iio_chrdev_buffer_release(struct iio_dev *indio_dev)
+{
+ struct iio_buffer *rb = indio_dev->buffer;
+
+ clear_bit(IIO_BUSY_BIT_POS, &rb->flags);
+ if (rb->access->unmark_in_use)
+ rb->access->unmark_in_use(rb);
+
+}
+
+void iio_buffer_init(struct iio_buffer *buffer, struct iio_dev *dev_info)
+{
+ buffer->indio_dev = dev_info;
+ init_waitqueue_head(&buffer->pollq);
+}
+EXPORT_SYMBOL(iio_buffer_init);
+
+static ssize_t iio_show_scan_index(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
+}
+
+static ssize_t iio_show_fixed_type(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ u8 type = this_attr->c->scan_type.endianness;
+
+ if (type == IIO_CPU) {
+ if (__LITTLE_ENDIAN)
+ type = IIO_LE;
+ else
+ type = IIO_BE;
+ }
+ return sprintf(buf, "%s:%c%d/%d>>%u\n",
+ iio_endian_prefix[type],
+ this_attr->c->scan_type.sign,
+ this_attr->c->scan_type.realbits,
+ this_attr->c->scan_type.storagebits,
+ this_attr->c->scan_type.shift);
+}
+
+static ssize_t iio_scan_el_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+
+ ret = iio_scan_mask_query(dev_info->buffer,
+ to_iio_dev_attr(attr)->address);
+ if (ret < 0)
+ return ret;
+ return sprintf(buf, "%d\n", ret);
+}
+
+static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
+{
+ clear_bit(bit, buffer->scan_mask);
+ buffer->scan_count--;
+ return 0;
+}
+
+static ssize_t iio_scan_el_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret = 0;
+ bool state;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+ state = !(buf[0] == '0');
+ mutex_lock(&indio_dev->mlock);
+ if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+ ret = -EBUSY;
+ goto error_ret;
+ }
+ ret = iio_scan_mask_query(buffer, this_attr->address);
+ if (ret < 0)
+ goto error_ret;
+ if (!state && ret) {
+ ret = iio_scan_mask_clear(buffer, this_attr->address);
+ if (ret)
+ goto error_ret;
+ } else if (state && !ret) {
+ ret = iio_scan_mask_set(buffer, this_attr->address);
+ if (ret)
+ goto error_ret;
+ }
+
+error_ret:
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret ? ret : len;
+
+}
+
+static ssize_t iio_scan_el_ts_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ return sprintf(buf, "%d\n", dev_info->buffer->scan_timestamp);
+}
+
+static ssize_t iio_scan_el_ts_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret = 0;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ bool state;
+
+ state = !(buf[0] == '0');
+ mutex_lock(&indio_dev->mlock);
+ if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+ ret = -EBUSY;
+ goto error_ret;
+ }
+ indio_dev->buffer->scan_timestamp = state;
+error_ret:
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret ? ret : len;
+}
+
+static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ int ret, attrcount = 0;
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ ret = __iio_add_chan_devattr("index",
+ chan,
+ &iio_show_scan_index,
+ NULL,
+ 0,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ if (ret)
+ goto error_ret;
+ attrcount++;
+ ret = __iio_add_chan_devattr("type",
+ chan,
+ &iio_show_fixed_type,
+ NULL,
+ 0,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ if (ret)
+ goto error_ret;
+ attrcount++;
+ if (chan->type != IIO_TIMESTAMP)
+ ret = __iio_add_chan_devattr("en",
+ chan,
+ &iio_scan_el_show,
+ &iio_scan_el_store,
+ chan->scan_index,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ else
+ ret = __iio_add_chan_devattr("en",
+ chan,
+ &iio_scan_el_ts_show,
+ &iio_scan_el_ts_store,
+ chan->scan_index,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ 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,
+ const struct iio_chan_spec *channels,
+ int num_channels)
+{
+ struct iio_dev_attr *p;
+ struct attribute **attr;
+ struct iio_buffer *buffer = indio_dev->buffer;
+ int ret, i, attrn, attrcount, attrcount_orig = 0;
+
+ if (buffer->attrs)
+ indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
+
+ if (buffer->scan_el_attrs != NULL) {
+ attr = buffer->scan_el_attrs->attrs;
+ while (*attr++ != NULL)
+ attrcount_orig++;
+ }
+ attrcount = attrcount_orig;
+ INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
+ if (channels) {
+ /* new magic */
+ for (i = 0; i < num_channels; i++) {
+ /* Establish necessary mask length */
+ if (channels[i].scan_index >
+ (int)indio_dev->masklength - 1)
+ indio_dev->masklength
+ = indio_dev->channels[i].scan_index + 1;
+
+ ret = iio_buffer_add_channel_sysfs(indio_dev,
+ &channels[i]);
+ if (ret < 0)
+ goto error_cleanup_dynamic;
+ attrcount += ret;
+ }
+ if (indio_dev->masklength && buffer->scan_mask == NULL) {
+ buffer->scan_mask
+ = kzalloc(sizeof(*buffer->scan_mask)*
+ BITS_TO_LONGS(indio_dev->masklength),
+ GFP_KERNEL);
+ if (buffer->scan_mask == NULL) {
+ ret = -ENOMEM;
+ goto error_cleanup_dynamic;
+ }
+ }
+ }
+
+ buffer->scan_el_group.name = iio_scan_elements_group_name;
+
+ buffer->scan_el_group.attrs
+ = kzalloc(sizeof(buffer->scan_el_group.attrs[0])*
+ (attrcount + 1),
+ GFP_KERNEL);
+ if (buffer->scan_el_group.attrs == NULL) {
+ ret = -ENOMEM;
+ goto error_free_scan_mask;
+ }
+ if (buffer->scan_el_attrs)
+ memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
+ sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
+ attrn = attrcount_orig;
+
+ list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
+ buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
+ indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
+
+ return 0;
+
+error_free_scan_mask:
+ kfree(buffer->scan_mask);
+error_cleanup_dynamic:
+ __iio_buffer_attr_cleanup(indio_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL(iio_buffer_register);
+
+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);
+}
+EXPORT_SYMBOL(iio_buffer_unregister);
+
+ssize_t iio_buffer_read_length(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ if (buffer->access->get_length)
+ return sprintf(buf, "%d\n",
+ buffer->access->get_length(buffer));
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_buffer_read_length);
+
+ssize_t iio_buffer_write_length(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ ulong val;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (buffer->access->get_length)
+ if (val == buffer->access->get_length(buffer))
+ return len;
+
+ if (buffer->access->set_length) {
+ buffer->access->set_length(buffer, val);
+ if (buffer->access->mark_param_change)
+ buffer->access->mark_param_change(buffer);
+ }
+
+ return len;
+}
+EXPORT_SYMBOL(iio_buffer_write_length);
+
+ssize_t iio_buffer_read_bytes_per_datum(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ if (buffer->access->get_bytes_per_datum)
+ return sprintf(buf, "%d\n",
+ buffer->access->get_bytes_per_datum(buffer));
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_buffer_read_bytes_per_datum);
+
+ssize_t iio_buffer_store_enable(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ bool requested_state, current_state;
+ int previous_mode;
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct iio_buffer *buffer = dev_info->buffer;
+
+ mutex_lock(&dev_info->mlock);
+ previous_mode = dev_info->currentmode;
+ requested_state = !(buf[0] == '0');
+ current_state = !!(previous_mode & INDIO_ALL_BUFFER_MODES);
+ if (current_state == requested_state) {
+ printk(KERN_INFO "iio-buffer, current state requested again\n");
+ goto done;
+ }
+ if (requested_state) {
+ if (buffer->setup_ops->preenable) {
+ ret = buffer->setup_ops->preenable(dev_info);
+ if (ret) {
+ printk(KERN_ERR
+ "Buffer not started:"
+ "buffer preenable failed\n");
+ goto error_ret;
+ }
+ }
+ if (buffer->access->request_update) {
+ ret = buffer->access->request_update(buffer);
+ if (ret) {
+ printk(KERN_INFO
+ "Buffer not started:"
+ "buffer parameter update failed\n");
+ goto error_ret;
+ }
+ }
+ if (buffer->access->mark_in_use)
+ buffer->access->mark_in_use(buffer);
+ /* Definitely possible for devices to support both of these.*/
+ if (dev_info->modes & INDIO_BUFFER_TRIGGERED) {
+ if (!dev_info->trig) {
+ printk(KERN_INFO
+ "Buffer not started: no trigger\n");
+ ret = -EINVAL;
+ if (buffer->access->unmark_in_use)
+ buffer->access->unmark_in_use(buffer);
+ goto error_ret;
+ }
+ dev_info->currentmode = INDIO_BUFFER_TRIGGERED;
+ } else if (dev_info->modes & INDIO_BUFFER_HARDWARE)
+ dev_info->currentmode = INDIO_BUFFER_HARDWARE;
+ else { /* should never be reached */
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
+ if (buffer->setup_ops->postenable) {
+ ret = buffer->setup_ops->postenable(dev_info);
+ if (ret) {
+ printk(KERN_INFO
+ "Buffer not started:"
+ "postenable failed\n");
+ if (buffer->access->unmark_in_use)
+ buffer->access->unmark_in_use(buffer);
+ dev_info->currentmode = previous_mode;
+ if (buffer->setup_ops->postdisable)
+ buffer->setup_ops->
+ postdisable(dev_info);
+ goto error_ret;
+ }
+ }
+ } else {
+ if (buffer->setup_ops->predisable) {
+ ret = buffer->setup_ops->predisable(dev_info);
+ if (ret)
+ goto error_ret;
+ }
+ if (buffer->access->unmark_in_use)
+ buffer->access->unmark_in_use(buffer);
+ dev_info->currentmode = INDIO_DIRECT_MODE;
+ if (buffer->setup_ops->postdisable) {
+ ret = buffer->setup_ops->postdisable(dev_info);
+ if (ret)
+ goto error_ret;
+ }
+ }
+done:
+ mutex_unlock(&dev_info->mlock);
+ return len;
+
+error_ret:
+ mutex_unlock(&dev_info->mlock);
+ return ret;
+}
+EXPORT_SYMBOL(iio_buffer_store_enable);
+
+ssize_t iio_buffer_show_enable(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ return sprintf(buf, "%d\n", !!(dev_info->currentmode
+ & INDIO_ALL_BUFFER_MODES));
+}
+EXPORT_SYMBOL(iio_buffer_show_enable);
+
+int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct iio_buffer *buffer = indio_dev->buffer;
+ size_t size;
+ dev_dbg(&indio_dev->dev, "%s\n", __func__);
+ /* Check if there are any scan elements enabled, if not fail*/
+ if (!(buffer->scan_count || buffer->scan_timestamp))
+ return -EINVAL;
+ if (buffer->scan_timestamp)
+ if (buffer->scan_count)
+ /* Timestamp (aligned to s64) and data */
+ size = (((buffer->scan_count * buffer->bpe)
+ + sizeof(s64) - 1)
+ & ~(sizeof(s64) - 1))
+ + sizeof(s64);
+ else /* Timestamp only */
+ size = sizeof(s64);
+ else /* Data only */
+ size = buffer->scan_count * buffer->bpe;
+ buffer->access->set_bytes_per_datum(buffer, size);
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_sw_buffer_preenable);
+
+
+/* note NULL used as error indicator as it doesn't make sense. */
+static unsigned long *iio_scan_mask_match(unsigned long *av_masks,
+ unsigned int masklength,
+ unsigned long *mask)
+{
+ if (bitmap_empty(mask, masklength))
+ return NULL;
+ while (*av_masks) {
+ if (bitmap_subset(mask, av_masks, masklength))
+ return av_masks;
+ av_masks += BITS_TO_LONGS(masklength);
+ }
+ return NULL;
+}
+
+/**
+ * iio_scan_mask_set() - set particular bit in the scan mask
+ * @buffer: the buffer whose scan mask we are interested in
+ * @bit: the bit to be set.
+ **/
+int iio_scan_mask_set(struct iio_buffer *buffer, int bit)
+{
+ struct iio_dev *dev_info = buffer->indio_dev;
+ unsigned long *mask;
+ unsigned long *trialmask;
+
+ trialmask = kmalloc(sizeof(*trialmask)*
+ BITS_TO_LONGS(dev_info->masklength),
+ GFP_KERNEL);
+
+ if (trialmask == NULL)
+ return -ENOMEM;
+ if (!dev_info->masklength) {
+ WARN_ON("trying to set scanmask prior to registering buffer\n");
+ kfree(trialmask);
+ return -EINVAL;
+ }
+ bitmap_copy(trialmask, buffer->scan_mask, dev_info->masklength);
+ set_bit(bit, trialmask);
+
+ if (dev_info->available_scan_masks) {
+ mask = iio_scan_mask_match(dev_info->available_scan_masks,
+ dev_info->masklength,
+ trialmask);
+ if (!mask) {
+ kfree(trialmask);
+ return -EINVAL;
+ }
+ }
+ bitmap_copy(buffer->scan_mask, trialmask, dev_info->masklength);
+ buffer->scan_count++;
+
+ kfree(trialmask);
+
+ return 0;
+};
+EXPORT_SYMBOL_GPL(iio_scan_mask_set);
+
+int iio_scan_mask_query(struct iio_buffer *buffer, int bit)
+{
+ struct iio_dev *dev_info = buffer->indio_dev;
+ long *mask;
+
+ if (bit > dev_info->masklength)
+ return -EINVAL;
+
+ if (!buffer->scan_mask)
+ return 0;
+ if (dev_info->available_scan_masks)
+ mask = iio_scan_mask_match(dev_info->available_scan_masks,
+ dev_info->masklength,
+ buffer->scan_mask);
+ else
+ mask = buffer->scan_mask;
+ if (!mask)
+ return 0;
+
+ return test_bit(bit, mask);
+};
+EXPORT_SYMBOL_GPL(iio_scan_mask_query);