/* 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 #include #include #include #include #include #include #include #include #include "iio_core.h" #include #include static const char * const iio_endian_prefix[] = { [IIO_BE] = "be", [IIO_LE] = "le", }; static bool iio_buffer_is_active(struct iio_buffer *buf) { return !list_empty(&buf->buffer_list); } static bool iio_buffer_data_available(struct iio_buffer *buf) { return buf->access->data_available(buf); } /** * 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; int ret; if (!indio_dev->info) return -ENODEV; if (!rb || !rb->access->read_first_n) return -EINVAL; do { if (!iio_buffer_data_available(rb)) { if (filp->f_flags & O_NONBLOCK) return -EAGAIN; ret = wait_event_interruptible(rb->pollq, iio_buffer_data_available(rb) || indio_dev->info == NULL); if (ret) return ret; if (indio_dev->info == NULL) return -ENODEV; } ret = rb->access->read_first_n(rb, n, buf); if (ret == 0 && (filp->f_flags & O_NONBLOCK)) ret = -EAGAIN; } while (ret == 0); return ret; } /** * 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; if (!indio_dev->info) return -ENODEV; poll_wait(filp, &rb->pollq, wait); if (iio_buffer_data_available(rb)) return POLLIN | POLLRDNORM; /* need a way of knowing if there may be enough data... */ 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); 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) { #ifdef __LITTLE_ENDIAN type = IIO_LE; #else type = IIO_BE; #endif } if (this_attr->c->scan_type.repeat > 1) return sprintf(buf, "%s:%c%d/%dX%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.repeat, this_attr->c->scan_type.shift); else 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 *indio_dev = dev_to_iio_dev(dev); /* Ensure ret is 0 or 1. */ ret = !!test_bit(to_iio_dev_attr(attr)->address, indio_dev->buffer->scan_mask); return sprintf(buf, "%d\n", ret); } static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit) { clear_bit(bit, buffer->scan_mask); return 0; } static ssize_t iio_scan_el_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; bool state; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = indio_dev->buffer; struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); ret = strtobool(buf, &state); if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; goto error_ret; } ret = iio_scan_mask_query(indio_dev, 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(indio_dev, buffer, this_attr->address); if (ret) goto error_ret; } error_ret: mutex_unlock(&indio_dev->mlock); return ret < 0 ? ret : len; } static ssize_t iio_scan_el_ts_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); return sprintf(buf, "%d\n", indio_dev->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; struct iio_dev *indio_dev = dev_to_iio_dev(dev); bool state; ret = strtobool(buf, &state); if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); if (iio_buffer_is_active(indio_dev->buffer)) { 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, IIO_SEPARATE, &indio_dev->dev, &buffer->scan_el_dev_attr_list); if (ret) return 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) return 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); if (ret) return ret; attrcount++; ret = attrcount; return ret; } 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++) { if (channels[i].scan_index < 0) continue; /* Establish necessary mask length */ if (channels[i].scan_index > (int)indio_dev->masklength - 1) indio_dev->masklength = 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 (channels[i].type == IIO_TIMESTAMP) indio_dev->scan_index_timestamp = channels[i].scan_index; } if (indio_dev->masklength && buffer->scan_mask == NULL) { buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(*buffer->scan_mask), 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 = kcalloc(attrcount + 1, sizeof(buffer->scan_el_group.attrs[0]), 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_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); 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_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list); } 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_to_iio_dev(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) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = indio_dev->buffer; unsigned int val; int ret; ret = kstrtouint(buf, 10, &val); if (ret) return ret; if (buffer->access->get_length) if (val == buffer->access->get_length(buffer)) return len; mutex_lock(&indio_dev->mlock); if (iio_buffer_is_active(indio_dev->buffer)) { ret = -EBUSY; } else { if (buffer->access->set_length) buffer->access->set_length(buffer, val); ret = 0; } mutex_unlock(&indio_dev->mlock); return ret ? ret : len; } EXPORT_SYMBOL(iio_buffer_write_length); ssize_t iio_buffer_show_enable(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); 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. */ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks, unsigned int masklength, const 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; } 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; int length, i; /* How much space will the demuxed element take? */ for_each_set_bit(i, mask, indio_dev->masklength) { ch = iio_find_channel_from_si(indio_dev, i); if (ch->scan_type.repeat > 1) length = ch->scan_type.storagebits / 8 * ch->scan_type.repeat; else length = ch->scan_type.storagebits / 8; bytes = ALIGN(bytes, length); bytes += length; } if (timestamp) { ch = iio_find_channel_from_si(indio_dev, indio_dev->scan_index_timestamp); if (ch->scan_type.repeat > 1) length = ch->scan_type.storagebits / 8 * ch->scan_type.repeat; else length = ch->scan_type.storagebits / 8; bytes = ALIGN(bytes, length); bytes += length; } 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; if (list_empty(&indio_dev->buffer_list)) return; if (indio_dev->setup_ops->predisable) indio_dev->setup_ops->predisable(indio_dev); list_for_each_entry_safe(buffer, _buffer, &indio_dev->buffer_list, buffer_list) iio_buffer_deactivate(buffer); indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) indio_dev->setup_ops->postdisable(indio_dev); if (indio_dev->available_scan_masks == NULL) kfree(indio_dev->active_scan_mask); } 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) { int ret; int success = 0; struct iio_buffer *buffer; unsigned long *compound_mask; const unsigned long *old_mask; /* Wind down existing buffers - iff there are any */ if (!list_empty(&indio_dev->buffer_list)) { if (indio_dev->setup_ops->predisable) { ret = indio_dev->setup_ops->predisable(indio_dev); if (ret) return ret; } indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) { ret = indio_dev->setup_ops->postdisable(indio_dev); if (ret) return ret; } } /* Keep a copy of current setup to allow roll back */ old_mask = indio_dev->active_scan_mask; if (!indio_dev->available_scan_masks) indio_dev->active_scan_mask = NULL; if (remove_buffer) iio_buffer_deactivate(remove_buffer); if (insert_buffer) iio_buffer_activate(indio_dev, insert_buffer); /* If no buffers in list, we are done */ if (list_empty(&indio_dev->buffer_list)) { indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->available_scan_masks == NULL) kfree(old_mask); return 0; } /* What scan mask do we actually have? */ compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long), GFP_KERNEL); if (compound_mask == NULL) { if (indio_dev->available_scan_masks == NULL) kfree(old_mask); return -ENOMEM; } indio_dev->scan_timestamp = 0; list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { bitmap_or(compound_mask, compound_mask, buffer->scan_mask, indio_dev->masklength); indio_dev->scan_timestamp |= buffer->scan_timestamp; } if (indio_dev->available_scan_masks) { indio_dev->active_scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks, indio_dev->masklength, compound_mask); if (indio_dev->active_scan_mask == NULL) { /* * Roll back. * Note can only occur when adding a buffer. */ iio_buffer_deactivate(insert_buffer); if (old_mask) { indio_dev->active_scan_mask = old_mask; success = -EINVAL; } else { kfree(compound_mask); ret = -EINVAL; return ret; } } } else { indio_dev->active_scan_mask = compound_mask; } iio_update_demux(indio_dev); /* Wind up again */ if (indio_dev->setup_ops->preenable) { ret = indio_dev->setup_ops->preenable(indio_dev); if (ret) { printk(KERN_ERR "Buffer not started: buffer preenable failed (%d)\n", ret); goto error_remove_inserted; } } indio_dev->scan_bytes = 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) { iio_buffer_update_bytes_per_datum(indio_dev, buffer); if (buffer->access->request_update) { ret = buffer->access->request_update(buffer); if (ret) { printk(KERN_INFO "Buffer not started: buffer parameter update failed (%d)\n", ret); goto error_run_postdisable; } } } if (indio_dev->info->update_scan_mode) { ret = indio_dev->info ->update_scan_mode(indio_dev, indio_dev->active_scan_mask); if (ret < 0) { printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret); goto error_run_postdisable; } } /* 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"); ret = -EINVAL; /* Can only occur on first buffer */ goto error_run_postdisable; } 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 */ ret = -EINVAL; goto error_run_postdisable; } if (indio_dev->setup_ops->postenable) { ret = indio_dev->setup_ops->postenable(indio_dev); if (ret) { printk(KERN_INFO "Buffer not started: postenable failed (%d)\n", ret); indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) indio_dev->setup_ops->postdisable(indio_dev); goto error_disable_all_buffers; } } if (indio_dev->available_scan_masks) kfree(compound_mask); else kfree(old_mask); return success; error_disable_all_buffers: indio_dev->currentmode = INDIO_DIRECT_MODE; error_run_postdisable: if (indio_dev->setup_ops->postdisable) indio_dev->setup_ops->postdisable(indio_dev); error_remove_inserted: if (insert_buffer) iio_buffer_deactivate(insert_buffer); indio_dev->active_scan_mask = old_mask; kfree(compound_mask); 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, struct device_attribute *attr, const char *buf, size_t len) { int ret; bool requested_state; struct iio_dev *indio_dev = dev_to_iio_dev(dev); bool inlist; ret = strtobool(buf, &requested_state); if (ret < 0) return ret; mutex_lock(&indio_dev->mlock); /* Find out if it is in the list */ 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, indio_dev->buffer, NULL); else ret = __iio_update_buffers(indio_dev, NULL, indio_dev->buffer); if (ret < 0) goto done; done: mutex_unlock(&indio_dev->mlock); return (ret < 0) ? ret : len; } EXPORT_SYMBOL(iio_buffer_store_enable); /** * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected * @indio_dev: the iio device * @mask: scan mask to be checked * * Return true if exactly one bit is set in the scan mask, false otherwise. It * can be used for devices where only one channel can be active for sampling at * a time. */ bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, const unsigned long *mask) { return bitmap_weight(mask, indio_dev->masklength) == 1; } EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot); static bool iio_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) { if (!indio_dev->setup_ops->validate_scan_mask) return true; return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask); } /** * 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. * * Note that at this point we have no way of knowing what other * buffers might request, hence this code only verifies that the * individual buffers request is plausible. */ int iio_scan_mask_set(struct iio_dev *indio_dev, struct iio_buffer *buffer, int bit) { const unsigned long *mask; unsigned long *trialmask; trialmask = kmalloc(sizeof(*trialmask)* BITS_TO_LONGS(indio_dev->masklength), GFP_KERNEL); if (trialmask == NULL) return -ENOMEM; if (!indio_dev->masklength) { WARN_ON("Trying to set scanmask prior to registering buffer\n"); goto err_invalid_mask; } bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength); set_bit(bit, trialmask); if (!iio_validate_scan_mask(indio_dev, trialmask)) goto err_invalid_mask; if (indio_dev->available_scan_masks) { mask = iio_scan_mask_match(indio_dev->available_scan_masks, indio_dev->masklength, trialmask); if (!mask) goto err_invalid_mask; } bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength); kfree(trialmask); return 0; err_invalid_mask: kfree(trialmask); return -EINVAL; } EXPORT_SYMBOL_GPL(iio_scan_mask_set); int iio_scan_mask_query(struct iio_dev *indio_dev, struct iio_buffer *buffer, int bit) { if (bit > indio_dev->masklength) return -EINVAL; if (!buffer->scan_mask) return 0; /* Ensure return value is 0 or 1. */ return !!test_bit(bit, buffer->scan_mask); }; EXPORT_SYMBOL_GPL(iio_scan_mask_query); /** * struct iio_demux_table() - table describing demux memcpy ops * @from: index to copy from * @to: index to copy to * @length: how many bytes to copy * @l: list head used for management */ struct iio_demux_table { unsigned from; unsigned to; unsigned length; struct list_head l; }; static const void *iio_demux(struct iio_buffer *buffer, const void *datain) { struct iio_demux_table *t; if (list_empty(&buffer->demux_list)) return datain; list_for_each_entry(t, &buffer->demux_list, l) memcpy(buffer->demux_bounce + t->to, datain + t->from, t->length); return buffer->demux_bounce; } static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data) { const void *dataout = iio_demux(buffer, data); return buffer->access->store_to(buffer, dataout); } static void iio_buffer_demux_free(struct iio_buffer *buffer) { struct iio_demux_table *p, *q; list_for_each_entry_safe(p, q, &buffer->demux_list, l) { list_del(&p->l); kfree(p); } } int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data) { int ret; struct iio_buffer *buf; list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) { ret = iio_push_to_buffer(buf, data); if (ret < 0) return ret; } return 0; } EXPORT_SYMBOL_GPL(iio_push_to_buffers); static int iio_buffer_add_demux(struct iio_buffer *buffer, struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc, unsigned int length) { if (*p && (*p)->from + (*p)->length == in_loc && (*p)->to + (*p)->length == out_loc) { (*p)->length += length; } else { *p = kmalloc(sizeof(*p), GFP_KERNEL); if (*p == NULL) return -ENOMEM; (*p)->from = in_loc; (*p)->to = out_loc; (*p)->length = length; list_add_tail(&(*p)->l, &buffer->demux_list); } return 0; } static int iio_buffer_update_demux(struct iio_dev *indio_dev, struct iio_buffer *buffer) { const struct iio_chan_spec *ch; int ret, in_ind = -1, out_ind, length; unsigned in_loc = 0, out_loc = 0; struct iio_demux_table *p = NULL; /* Clear out any old demux */ iio_buffer_demux_free(buffer); kfree(buffer->demux_bounce); buffer->demux_bounce = NULL; /* First work out which scan mode we will actually have */ if (bitmap_equal(indio_dev->active_scan_mask, buffer->scan_mask, indio_dev->masklength)) return 0; /* Now we have the two masks, work from least sig and build up sizes */ for_each_set_bit(out_ind, indio_dev->active_scan_mask, indio_dev->masklength) { in_ind = find_next_bit(indio_dev->active_scan_mask, indio_dev->masklength, in_ind + 1); while (in_ind != out_ind) { in_ind = find_next_bit(indio_dev->active_scan_mask, indio_dev->masklength, in_ind + 1); ch = iio_find_channel_from_si(indio_dev, in_ind); if (ch->scan_type.repeat > 1) length = ch->scan_type.storagebits / 8 * ch->scan_type.repeat; else length = ch->scan_type.storagebits / 8; /* Make sure we are aligned */ in_loc = roundup(in_loc, length) + length; } ch = iio_find_channel_from_si(indio_dev, in_ind); if (ch->scan_type.repeat > 1) length = ch->scan_type.storagebits / 8 * ch->scan_type.repeat; else length = ch->scan_type.storagebits / 8; out_loc = roundup(out_loc, length); in_loc = roundup(in_loc, length); ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length); if (ret) goto error_clear_mux_table; out_loc += length; in_loc += length; } /* Relies on scan_timestamp being last */ if (buffer->scan_timestamp) { ch = iio_find_channel_from_si(indio_dev, indio_dev->scan_index_timestamp); if (ch->scan_type.repeat > 1) length = ch->scan_type.storagebits / 8 * ch->scan_type.repeat; else length = ch->scan_type.storagebits / 8; out_loc = roundup(out_loc, length); in_loc = roundup(in_loc, length); ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length); if (ret) goto error_clear_mux_table; out_loc += length; in_loc += length; } buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL); if (buffer->demux_bounce == NULL) { ret = -ENOMEM; goto error_clear_mux_table; } return 0; error_clear_mux_table: iio_buffer_demux_free(buffer); return ret; } int iio_update_demux(struct iio_dev *indio_dev) { struct iio_buffer *buffer; int ret; list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { ret = iio_buffer_update_demux(indio_dev, buffer); if (ret < 0) goto error_clear_mux_table; } return 0; error_clear_mux_table: list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) iio_buffer_demux_free(buffer); 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);