| /* 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/export.h> |
| #include <linux/device.h> |
| #include <linux/fs.h> |
| #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" |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/buffer.h> |
| |
| 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 size_t iio_buffer_data_available(struct iio_buffer *buf) |
| { |
| return buf->access->data_available(buf); |
| } |
| |
| static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev, |
| struct iio_buffer *buf, size_t required) |
| { |
| if (!indio_dev->info->hwfifo_flush_to_buffer) |
| return -ENODEV; |
| |
| return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required); |
| } |
| |
| static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf, |
| size_t to_wait, int to_flush) |
| { |
| size_t avail; |
| int flushed = 0; |
| |
| /* wakeup if the device was unregistered */ |
| if (!indio_dev->info) |
| return true; |
| |
| /* drain the buffer if it was disabled */ |
| if (!iio_buffer_is_active(buf)) { |
| to_wait = min_t(size_t, to_wait, 1); |
| to_flush = 0; |
| } |
| |
| avail = iio_buffer_data_available(buf); |
| |
| if (avail >= to_wait) { |
| /* force a flush for non-blocking reads */ |
| if (!to_wait && avail < to_flush) |
| iio_buffer_flush_hwfifo(indio_dev, buf, |
| to_flush - avail); |
| return true; |
| } |
| |
| if (to_flush) |
| flushed = iio_buffer_flush_hwfifo(indio_dev, buf, |
| to_wait - avail); |
| if (flushed <= 0) |
| return false; |
| |
| if (avail + flushed >= to_wait) |
| return true; |
| |
| return false; |
| } |
| |
| /** |
| * iio_buffer_read_first_n_outer() - chrdev read for buffer access |
| * @filp: File structure pointer for the char device |
| * @buf: Destination buffer for iio buffer read |
| * @n: First n bytes to read |
| * @f_ps: Long offset provided by the user as a seek position |
| * |
| * This function relies on all buffer implementations having an |
| * iio_buffer as their first element. |
| * |
| * Return: negative values corresponding to error codes or ret != 0 |
| * for ending the reading activity |
| **/ |
| 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; |
| size_t datum_size; |
| size_t to_wait; |
| int ret; |
| |
| if (!indio_dev->info) |
| return -ENODEV; |
| |
| if (!rb || !rb->access->read_first_n) |
| return -EINVAL; |
| |
| datum_size = rb->bytes_per_datum; |
| |
| /* |
| * If datum_size is 0 there will never be anything to read from the |
| * buffer, so signal end of file now. |
| */ |
| if (!datum_size) |
| return 0; |
| |
| if (filp->f_flags & O_NONBLOCK) |
| to_wait = 0; |
| else |
| to_wait = min_t(size_t, n / datum_size, rb->watermark); |
| |
| do { |
| ret = wait_event_interruptible(rb->pollq, |
| iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)); |
| if (ret) |
| return ret; |
| |
| if (!indio_dev->info) |
| 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 |
| * @filp: File structure pointer for device access |
| * @wait: Poll table structure pointer for which the driver adds |
| * a wait queue |
| * |
| * Return: (POLLIN | POLLRDNORM) if data is available for reading |
| * or 0 for other cases |
| */ |
| 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 0; |
| |
| poll_wait(filp, &rb->pollq, wait); |
| if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0)) |
| return POLLIN | POLLRDNORM; |
| 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); |
| if (!buffer->watermark) |
| buffer->watermark = 1; |
| } |
| 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); |
| } |
| |
| /* 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, |
| bool strict) |
| { |
| if (bitmap_empty(mask, masklength)) |
| return NULL; |
| while (*av_masks) { |
| if (strict) { |
| if (bitmap_equal(mask, av_masks, masklength)) |
| return av_masks; |
| } else { |
| if (bitmap_subset(mask, av_masks, masklength)) |
| return av_masks; |
| } |
| av_masks += BITS_TO_LONGS(masklength); |
| } |
| return NULL; |
| } |
| |
| 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. |
| */ |
| static 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(1, "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, false); |
| 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; |
| } |
| |
| 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 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; |
| |
| return sprintf(buf, "%d\n", buffer->length); |
| } |
| |
| static 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 (val == buffer->length) |
| return len; |
| |
| mutex_lock(&indio_dev->mlock); |
| if (iio_buffer_is_active(indio_dev->buffer)) { |
| ret = -EBUSY; |
| } else { |
| buffer->access->set_length(buffer, val); |
| ret = 0; |
| } |
| if (ret) |
| goto out; |
| if (buffer->length && buffer->length < buffer->watermark) |
| buffer->watermark = buffer->length; |
| out: |
| mutex_unlock(&indio_dev->mlock); |
| |
| return ret ? ret : len; |
| } |
| |
| static 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)); |
| } |
| |
| static unsigned int iio_storage_bytes_for_si(struct iio_dev *indio_dev, |
| unsigned int scan_index) |
| { |
| const struct iio_chan_spec *ch; |
| unsigned int bytes; |
| |
| ch = iio_find_channel_from_si(indio_dev, scan_index); |
| bytes = ch->scan_type.storagebits / 8; |
| if (ch->scan_type.repeat > 1) |
| bytes *= ch->scan_type.repeat; |
| return bytes; |
| } |
| |
| static unsigned int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev) |
| { |
| return iio_storage_bytes_for_si(indio_dev, |
| indio_dev->scan_index_timestamp); |
| } |
| |
| static int iio_compute_scan_bytes(struct iio_dev *indio_dev, |
| const unsigned long *mask, bool timestamp) |
| { |
| unsigned bytes = 0; |
| int length, i; |
| |
| /* How much space will the demuxed element take? */ |
| for_each_set_bit(i, mask, |
| indio_dev->masklength) { |
| length = iio_storage_bytes_for_si(indio_dev, i); |
| bytes = ALIGN(bytes, length); |
| bytes += length; |
| } |
| |
| if (timestamp) { |
| length = iio_storage_bytes_for_timestamp(indio_dev); |
| 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); |
| wake_up_interruptible(&buffer->pollq); |
| iio_buffer_put(buffer); |
| } |
| |
| static void iio_buffer_deactivate_all(struct iio_dev *indio_dev) |
| { |
| struct iio_buffer *buffer, *_buffer; |
| |
| list_for_each_entry_safe(buffer, _buffer, |
| &indio_dev->buffer_list, buffer_list) |
| iio_buffer_deactivate(buffer); |
| } |
| |
| static int iio_buffer_enable(struct iio_buffer *buffer, |
| struct iio_dev *indio_dev) |
| { |
| if (!buffer->access->enable) |
| return 0; |
| return buffer->access->enable(buffer, indio_dev); |
| } |
| |
| static int iio_buffer_disable(struct iio_buffer *buffer, |
| struct iio_dev *indio_dev) |
| { |
| if (!buffer->access->disable) |
| return 0; |
| return buffer->access->disable(buffer, 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_buffer_request_update(struct iio_dev *indio_dev, |
| struct iio_buffer *buffer) |
| { |
| int ret; |
| |
| iio_buffer_update_bytes_per_datum(indio_dev, buffer); |
| if (buffer->access->request_update) { |
| ret = buffer->access->request_update(buffer); |
| if (ret) { |
| dev_dbg(&indio_dev->dev, |
| "Buffer not started: buffer parameter update failed (%d)\n", |
| ret); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void iio_free_scan_mask(struct iio_dev *indio_dev, |
| const unsigned long *mask) |
| { |
| /* If the mask is dynamically allocated free it, otherwise do nothing */ |
| if (!indio_dev->available_scan_masks) |
| kfree(mask); |
| } |
| |
| struct iio_device_config { |
| unsigned int mode; |
| unsigned int watermark; |
| const unsigned long *scan_mask; |
| unsigned int scan_bytes; |
| bool scan_timestamp; |
| }; |
| |
| static int iio_verify_update(struct iio_dev *indio_dev, |
| struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer, |
| struct iio_device_config *config) |
| { |
| unsigned long *compound_mask; |
| const unsigned long *scan_mask; |
| bool strict_scanmask = false; |
| struct iio_buffer *buffer; |
| bool scan_timestamp; |
| unsigned int modes; |
| |
| memset(config, 0, sizeof(*config)); |
| |
| /* |
| * If there is just one buffer and we are removing it there is nothing |
| * to verify. |
| */ |
| if (remove_buffer && !insert_buffer && |
| list_is_singular(&indio_dev->buffer_list)) |
| return 0; |
| |
| modes = indio_dev->modes; |
| |
| list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { |
| if (buffer == remove_buffer) |
| continue; |
| modes &= buffer->access->modes; |
| config->watermark = min(config->watermark, buffer->watermark); |
| } |
| |
| if (insert_buffer) { |
| modes &= insert_buffer->access->modes; |
| config->watermark = min(config->watermark, |
| insert_buffer->watermark); |
| } |
| |
| /* Definitely possible for devices to support both of these. */ |
| if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) { |
| config->mode = INDIO_BUFFER_TRIGGERED; |
| } else if (modes & INDIO_BUFFER_HARDWARE) { |
| /* |
| * Keep things simple for now and only allow a single buffer to |
| * be connected in hardware mode. |
| */ |
| if (insert_buffer && !list_empty(&indio_dev->buffer_list)) |
| return -EINVAL; |
| config->mode = INDIO_BUFFER_HARDWARE; |
| strict_scanmask = true; |
| } else if (modes & INDIO_BUFFER_SOFTWARE) { |
| config->mode = INDIO_BUFFER_SOFTWARE; |
| } else { |
| /* Can only occur on first buffer */ |
| if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) |
| dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n"); |
| return -EINVAL; |
| } |
| |
| /* What scan mask do we actually have? */ |
| compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), |
| sizeof(long), GFP_KERNEL); |
| if (compound_mask == NULL) |
| return -ENOMEM; |
| |
| scan_timestamp = false; |
| |
| list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { |
| if (buffer == remove_buffer) |
| continue; |
| bitmap_or(compound_mask, compound_mask, buffer->scan_mask, |
| indio_dev->masklength); |
| scan_timestamp |= buffer->scan_timestamp; |
| } |
| |
| if (insert_buffer) { |
| bitmap_or(compound_mask, compound_mask, |
| insert_buffer->scan_mask, indio_dev->masklength); |
| scan_timestamp |= insert_buffer->scan_timestamp; |
| } |
| |
| if (indio_dev->available_scan_masks) { |
| scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks, |
| indio_dev->masklength, |
| compound_mask, |
| strict_scanmask); |
| kfree(compound_mask); |
| if (scan_mask == NULL) |
| return -EINVAL; |
| } else { |
| scan_mask = compound_mask; |
| } |
| |
| config->scan_bytes = iio_compute_scan_bytes(indio_dev, |
| scan_mask, scan_timestamp); |
| config->scan_mask = scan_mask; |
| config->scan_timestamp = scan_timestamp; |
| |
| return 0; |
| } |
| |
| static int iio_enable_buffers(struct iio_dev *indio_dev, |
| struct iio_device_config *config) |
| { |
| struct iio_buffer *buffer; |
| int ret; |
| |
| indio_dev->active_scan_mask = config->scan_mask; |
| indio_dev->scan_timestamp = config->scan_timestamp; |
| indio_dev->scan_bytes = config->scan_bytes; |
| |
| iio_update_demux(indio_dev); |
| |
| /* Wind up again */ |
| if (indio_dev->setup_ops->preenable) { |
| ret = indio_dev->setup_ops->preenable(indio_dev); |
| if (ret) { |
| dev_dbg(&indio_dev->dev, |
| "Buffer not started: buffer preenable failed (%d)\n", ret); |
| goto err_undo_config; |
| } |
| } |
| |
| if (indio_dev->info->update_scan_mode) { |
| ret = indio_dev->info |
| ->update_scan_mode(indio_dev, |
| indio_dev->active_scan_mask); |
| if (ret < 0) { |
| dev_dbg(&indio_dev->dev, |
| "Buffer not started: update scan mode failed (%d)\n", |
| ret); |
| goto err_run_postdisable; |
| } |
| } |
| |
| if (indio_dev->info->hwfifo_set_watermark) |
| indio_dev->info->hwfifo_set_watermark(indio_dev, |
| config->watermark); |
| |
| list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { |
| ret = iio_buffer_enable(buffer, indio_dev); |
| if (ret) |
| goto err_disable_buffers; |
| } |
| |
| indio_dev->currentmode = config->mode; |
| |
| if (indio_dev->setup_ops->postenable) { |
| ret = indio_dev->setup_ops->postenable(indio_dev); |
| if (ret) { |
| dev_dbg(&indio_dev->dev, |
| "Buffer not started: postenable failed (%d)\n", ret); |
| goto err_disable_buffers; |
| } |
| } |
| |
| return 0; |
| |
| err_disable_buffers: |
| list_for_each_entry_continue_reverse(buffer, &indio_dev->buffer_list, |
| buffer_list) |
| iio_buffer_disable(buffer, indio_dev); |
| err_run_postdisable: |
| indio_dev->currentmode = INDIO_DIRECT_MODE; |
| if (indio_dev->setup_ops->postdisable) |
| indio_dev->setup_ops->postdisable(indio_dev); |
| err_undo_config: |
| indio_dev->active_scan_mask = NULL; |
| |
| return ret; |
| } |
| |
| static int iio_disable_buffers(struct iio_dev *indio_dev) |
| { |
| struct iio_buffer *buffer; |
| int ret = 0; |
| int ret2; |
| |
| /* Wind down existing buffers - iff there are any */ |
| if (list_empty(&indio_dev->buffer_list)) |
| return 0; |
| |
| /* |
| * If things go wrong at some step in disable we still need to continue |
| * to perform the other steps, otherwise we leave the device in a |
| * inconsistent state. We return the error code for the first error we |
| * encountered. |
| */ |
| |
| if (indio_dev->setup_ops->predisable) { |
| ret2 = indio_dev->setup_ops->predisable(indio_dev); |
| if (ret2 && !ret) |
| ret = ret2; |
| } |
| |
| list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { |
| ret2 = iio_buffer_disable(buffer, indio_dev); |
| if (ret2 && !ret) |
| ret = ret2; |
| } |
| |
| indio_dev->currentmode = INDIO_DIRECT_MODE; |
| |
| if (indio_dev->setup_ops->postdisable) { |
| ret2 = indio_dev->setup_ops->postdisable(indio_dev); |
| if (ret2 && !ret) |
| ret = ret2; |
| } |
| |
| iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask); |
| indio_dev->active_scan_mask = NULL; |
| |
| return ret; |
| } |
| |
| static int __iio_update_buffers(struct iio_dev *indio_dev, |
| struct iio_buffer *insert_buffer, |
| struct iio_buffer *remove_buffer) |
| { |
| struct iio_device_config new_config; |
| int ret; |
| |
| ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer, |
| &new_config); |
| if (ret) |
| return ret; |
| |
| if (insert_buffer) { |
| ret = iio_buffer_request_update(indio_dev, insert_buffer); |
| if (ret) |
| goto err_free_config; |
| } |
| |
| ret = iio_disable_buffers(indio_dev); |
| if (ret) |
| goto err_deactivate_all; |
| |
| 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)) |
| return 0; |
| |
| ret = iio_enable_buffers(indio_dev, &new_config); |
| if (ret) |
| goto err_deactivate_all; |
| |
| return 0; |
| |
| err_deactivate_all: |
| /* |
| * We've already verified that the config is valid earlier. If things go |
| * wrong in either enable or disable the most likely reason is an IO |
| * error from the device. In this case there is no good recovery |
| * strategy. Just make sure to disable everything and leave the device |
| * in a sane state. With a bit of luck the device might come back to |
| * life again later and userspace can try again. |
| */ |
| iio_buffer_deactivate_all(indio_dev); |
| |
| err_free_config: |
| iio_free_scan_mask(indio_dev, new_config.scan_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); |
| |
| void iio_disable_all_buffers(struct iio_dev *indio_dev) |
| { |
| iio_disable_buffers(indio_dev); |
| iio_buffer_deactivate_all(indio_dev); |
| } |
| |
| static 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); |
| |
| done: |
| mutex_unlock(&indio_dev->mlock); |
| return (ret < 0) ? ret : len; |
| } |
| |
| static const char * const iio_scan_elements_group_name = "scan_elements"; |
| |
| static ssize_t iio_buffer_show_watermark(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; |
| |
| return sprintf(buf, "%u\n", buffer->watermark); |
| } |
| |
| static ssize_t iio_buffer_store_watermark(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 (!val) |
| return -EINVAL; |
| |
| mutex_lock(&indio_dev->mlock); |
| |
| if (val > buffer->length) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| if (iio_buffer_is_active(indio_dev->buffer)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| buffer->watermark = val; |
| out: |
| mutex_unlock(&indio_dev->mlock); |
| |
| return ret ? ret : len; |
| } |
| |
| static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length, |
| iio_buffer_write_length); |
| static struct device_attribute dev_attr_length_ro = __ATTR(length, |
| S_IRUGO, iio_buffer_read_length, NULL); |
| static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, |
| iio_buffer_show_enable, iio_buffer_store_enable); |
| static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR, |
| iio_buffer_show_watermark, iio_buffer_store_watermark); |
| static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark, |
| S_IRUGO, iio_buffer_show_watermark, NULL); |
| |
| static struct attribute *iio_buffer_attrs[] = { |
| &dev_attr_length.attr, |
| &dev_attr_enable.attr, |
| &dev_attr_watermark.attr, |
| }; |
| |
| int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) |
| { |
| struct iio_dev_attr *p; |
| struct attribute **attr; |
| struct iio_buffer *buffer = indio_dev->buffer; |
| int ret, i, attrn, attrcount, attrcount_orig = 0; |
| const struct iio_chan_spec *channels; |
| |
| channels = indio_dev->channels; |
| if (channels) { |
| int ml = indio_dev->masklength; |
| |
| for (i = 0; i < indio_dev->num_channels; i++) |
| ml = max(ml, channels[i].scan_index + 1); |
| indio_dev->masklength = ml; |
| } |
| |
| if (!buffer) |
| return 0; |
| |
| attrcount = 0; |
| if (buffer->attrs) { |
| while (buffer->attrs[attrcount] != NULL) |
| attrcount++; |
| } |
| |
| attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1, |
| sizeof(struct attribute *), GFP_KERNEL); |
| if (!attr) |
| return -ENOMEM; |
| |
| memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); |
| if (!buffer->access->set_length) |
| attr[0] = &dev_attr_length_ro.attr; |
| |
| if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) |
| attr[2] = &dev_attr_watermark_ro.attr; |
| |
| if (buffer->attrs) |
| memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, |
| sizeof(struct attribute *) * attrcount); |
| |
| attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL; |
| |
| buffer->buffer_group.name = "buffer"; |
| buffer->buffer_group.attrs = attr; |
| |
| indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group; |
| |
| 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); |
| channels = indio_dev->channels; |
| if (channels) { |
| /* new magic */ |
| for (i = 0; i < indio_dev->num_channels; i++) { |
| if (channels[i].scan_index < 0) |
| continue; |
| |
| 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); |
| kfree(indio_dev->buffer->buffer_group.attrs); |
| |
| return ret; |
| } |
| |
| void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) |
| { |
| if (!indio_dev->buffer) |
| return; |
| |
| kfree(indio_dev->buffer->scan_mask); |
| kfree(indio_dev->buffer->buffer_group.attrs); |
| kfree(indio_dev->buffer->scan_el_group.attrs); |
| iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list); |
| } |
| |
| /** |
| * 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); |
| |
| 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); |
| int ret; |
| |
| ret = buffer->access->store_to(buffer, dataout); |
| if (ret) |
| return ret; |
| |
| /* |
| * We can't just test for watermark to decide if we wake the poll queue |
| * because read may request less samples than the watermark. |
| */ |
| wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM); |
| return 0; |
| } |
| |
| 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) |
| { |
| 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, |
| buffer->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); |
| length = iio_storage_bytes_for_si(indio_dev, in_ind); |
| /* Make sure we are aligned */ |
| in_loc = roundup(in_loc, length) + length; |
| } |
| length = iio_storage_bytes_for_si(indio_dev, in_ind); |
| 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) { |
| length = iio_storage_bytes_for_timestamp(indio_dev); |
| 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); |