diff options
Diffstat (limited to 'drivers/iio/inkern.c')
| -rw-r--r-- | drivers/iio/inkern.c | 958 |
1 files changed, 958 insertions, 0 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c new file mode 100644 index 000000000..a8ccc6e5a --- /dev/null +++ b/drivers/iio/inkern.c @@ -0,0 +1,958 @@ +/* The industrial I/O core in kernel channel mapping + * + * Copyright (c) 2011 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. + */ +#include <linux/err.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/of.h> + +#include <linux/iio/iio.h> +#include "iio_core.h" +#include <linux/iio/machine.h> +#include <linux/iio/driver.h> +#include <linux/iio/consumer.h> + +struct iio_map_internal { + struct iio_dev *indio_dev; + struct iio_map *map; + struct list_head l; +}; + +static LIST_HEAD(iio_map_list); +static DEFINE_MUTEX(iio_map_list_lock); + +int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps) +{ + int i = 0, ret = 0; + struct iio_map_internal *mapi; + + if (maps == NULL) + return 0; + + mutex_lock(&iio_map_list_lock); + while (maps[i].consumer_dev_name != NULL) { + mapi = kzalloc(sizeof(*mapi), GFP_KERNEL); + if (mapi == NULL) { + ret = -ENOMEM; + goto error_ret; + } + mapi->map = &maps[i]; + mapi->indio_dev = indio_dev; + list_add_tail(&mapi->l, &iio_map_list); + i++; + } +error_ret: + mutex_unlock(&iio_map_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_map_array_register); + + +/* + * Remove all map entries associated with the given iio device + */ +int iio_map_array_unregister(struct iio_dev *indio_dev) +{ + int ret = -ENODEV; + struct iio_map_internal *mapi, *next; + + mutex_lock(&iio_map_list_lock); + list_for_each_entry_safe(mapi, next, &iio_map_list, l) { + if (indio_dev == mapi->indio_dev) { + list_del(&mapi->l); + kfree(mapi); + ret = 0; + } + } + mutex_unlock(&iio_map_list_lock); + return ret; +} +EXPORT_SYMBOL_GPL(iio_map_array_unregister); + +static const struct iio_chan_spec +*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name) +{ + int i; + const struct iio_chan_spec *chan = NULL; + + for (i = 0; i < indio_dev->num_channels; i++) + if (indio_dev->channels[i].datasheet_name && + strcmp(name, indio_dev->channels[i].datasheet_name) == 0) { + chan = &indio_dev->channels[i]; + break; + } + return chan; +} + +#ifdef CONFIG_OF + +static int iio_dev_node_match(struct device *dev, void *data) +{ + return dev->of_node == data && dev->type == &iio_device_type; +} + +/** + * __of_iio_simple_xlate - translate iiospec to the IIO channel index + * @indio_dev: pointer to the iio_dev structure + * @iiospec: IIO specifier as found in the device tree + * + * This is simple translation function, suitable for the most 1:1 mapped + * channels in IIO chips. This function performs only one sanity check: + * whether IIO index is less than num_channels (that is specified in the + * iio_dev). + */ +static int __of_iio_simple_xlate(struct iio_dev *indio_dev, + const struct of_phandle_args *iiospec) +{ + if (!iiospec->args_count) + return 0; + + if (iiospec->args[0] >= indio_dev->num_channels) { + dev_err(&indio_dev->dev, "invalid channel index %u\n", + iiospec->args[0]); + return -EINVAL; + } + + return iiospec->args[0]; +} + +static int __of_iio_channel_get(struct iio_channel *channel, + struct device_node *np, int index) +{ + struct device *idev; + struct iio_dev *indio_dev; + int err; + struct of_phandle_args iiospec; + + err = of_parse_phandle_with_args(np, "io-channels", + "#io-channel-cells", + index, &iiospec); + if (err) + return err; + + idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, + iio_dev_node_match); + of_node_put(iiospec.np); + if (idev == NULL) + return -EPROBE_DEFER; + + indio_dev = dev_to_iio_dev(idev); + channel->indio_dev = indio_dev; + if (indio_dev->info->of_xlate) + index = indio_dev->info->of_xlate(indio_dev, &iiospec); + else + index = __of_iio_simple_xlate(indio_dev, &iiospec); + if (index < 0) + goto err_put; + channel->channel = &indio_dev->channels[index]; + + return 0; + +err_put: + iio_device_put(indio_dev); + return index; +} + +static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) +{ + struct iio_channel *channel; + int err; + + if (index < 0) + return ERR_PTR(-EINVAL); + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (channel == NULL) + return ERR_PTR(-ENOMEM); + + err = __of_iio_channel_get(channel, np, index); + if (err) + goto err_free_channel; + + return channel; + +err_free_channel: + kfree(channel); + return ERR_PTR(err); +} + +static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np, + const char *name) +{ + struct iio_channel *chan = NULL; + + /* Walk up the tree of devices looking for a matching iio channel */ + while (np) { + int index = 0; + + /* + * For named iio channels, first look up the name in the + * "io-channel-names" property. If it cannot be found, the + * index will be an error code, and of_iio_channel_get() + * will fail. + */ + if (name) + index = of_property_match_string(np, "io-channel-names", + name); + chan = of_iio_channel_get(np, index); + if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) + break; + else if (name && index >= 0) { + pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n", + np, name ? name : "", index); + return NULL; + } + + /* + * No matching IIO channel found on this node. + * If the parent node has a "io-channel-ranges" property, + * then we can try one of its channels. + */ + np = np->parent; + if (np && !of_get_property(np, "io-channel-ranges", NULL)) + return NULL; + } + + return chan; +} + +static struct iio_channel *of_iio_channel_get_all(struct device *dev) +{ + struct iio_channel *chans; + int i, mapind, nummaps = 0; + int ret; + + do { + ret = of_parse_phandle_with_args(dev->of_node, + "io-channels", + "#io-channel-cells", + nummaps, NULL); + if (ret < 0) + break; + } while (++nummaps); + + if (nummaps == 0) /* no error, return NULL to search map table */ + return NULL; + + /* NULL terminated array to save passing size */ + chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL); + if (chans == NULL) + return ERR_PTR(-ENOMEM); + + /* Search for OF matches */ + for (mapind = 0; mapind < nummaps; mapind++) { + ret = __of_iio_channel_get(&chans[mapind], dev->of_node, + mapind); + if (ret) + goto error_free_chans; + } + return chans; + +error_free_chans: + for (i = 0; i < mapind; i++) + iio_device_put(chans[i].indio_dev); + kfree(chans); + return ERR_PTR(ret); +} + +#else /* CONFIG_OF */ + +static inline struct iio_channel * +of_iio_channel_get_by_name(struct device_node *np, const char *name) +{ + return NULL; +} + +static inline struct iio_channel *of_iio_channel_get_all(struct device *dev) +{ + return NULL; +} + +#endif /* CONFIG_OF */ + +static struct iio_channel *iio_channel_get_sys(const char *name, + const char *channel_name) +{ + struct iio_map_internal *c_i = NULL, *c = NULL; + struct iio_channel *channel; + int err; + + if (name == NULL && channel_name == NULL) + return ERR_PTR(-ENODEV); + + /* first find matching entry the channel map */ + mutex_lock(&iio_map_list_lock); + list_for_each_entry(c_i, &iio_map_list, l) { + if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) || + (channel_name && + strcmp(channel_name, c_i->map->consumer_channel) != 0)) + continue; + c = c_i; + iio_device_get(c->indio_dev); + break; + } + mutex_unlock(&iio_map_list_lock); + if (c == NULL) + return ERR_PTR(-ENODEV); + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (channel == NULL) { + err = -ENOMEM; + goto error_no_mem; + } + + channel->indio_dev = c->indio_dev; + + if (c->map->adc_channel_label) { + channel->channel = + iio_chan_spec_from_name(channel->indio_dev, + c->map->adc_channel_label); + + if (channel->channel == NULL) { + err = -EINVAL; + goto error_no_chan; + } + } + + return channel; + +error_no_chan: + kfree(channel); +error_no_mem: + iio_device_put(c->indio_dev); + return ERR_PTR(err); +} + +struct iio_channel *iio_channel_get(struct device *dev, + const char *channel_name) +{ + const char *name = dev ? dev_name(dev) : NULL; + struct iio_channel *channel; + + if (dev) { + channel = of_iio_channel_get_by_name(dev->of_node, + channel_name); + if (channel != NULL) + return channel; + } + + return iio_channel_get_sys(name, channel_name); +} +EXPORT_SYMBOL_GPL(iio_channel_get); + +void iio_channel_release(struct iio_channel *channel) +{ + if (!channel) + return; + iio_device_put(channel->indio_dev); + kfree(channel); +} +EXPORT_SYMBOL_GPL(iio_channel_release); + +static void devm_iio_channel_free(struct device *dev, void *res) +{ + struct iio_channel *channel = *(struct iio_channel **)res; + + iio_channel_release(channel); +} + +static int devm_iio_channel_match(struct device *dev, void *res, void *data) +{ + struct iio_channel **r = res; + + if (!r || !*r) { + WARN_ON(!r || !*r); + return 0; + } + + return *r == data; +} + +struct iio_channel *devm_iio_channel_get(struct device *dev, + const char *channel_name) +{ + struct iio_channel **ptr, *channel; + + ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + channel = iio_channel_get(dev, channel_name); + if (IS_ERR(channel)) { + devres_free(ptr); + return channel; + } + + *ptr = channel; + devres_add(dev, ptr); + + return channel; +} +EXPORT_SYMBOL_GPL(devm_iio_channel_get); + +void devm_iio_channel_release(struct device *dev, struct iio_channel *channel) +{ + WARN_ON(devres_release(dev, devm_iio_channel_free, + devm_iio_channel_match, channel)); +} +EXPORT_SYMBOL_GPL(devm_iio_channel_release); + +struct iio_channel *iio_channel_get_all(struct device *dev) +{ + const char *name; + struct iio_channel *chans; + struct iio_map_internal *c = NULL; + int nummaps = 0; + int mapind = 0; + int i, ret; + + if (dev == NULL) + return ERR_PTR(-EINVAL); + + chans = of_iio_channel_get_all(dev); + if (chans) + return chans; + + name = dev_name(dev); + + mutex_lock(&iio_map_list_lock); + /* first count the matching maps */ + list_for_each_entry(c, &iio_map_list, l) + if (name && strcmp(name, c->map->consumer_dev_name) != 0) + continue; + else + nummaps++; + + if (nummaps == 0) { + ret = -ENODEV; + goto error_ret; + } + + /* NULL terminated array to save passing size */ + chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL); + if (chans == NULL) { + ret = -ENOMEM; + goto error_ret; + } + + /* for each map fill in the chans element */ + list_for_each_entry(c, &iio_map_list, l) { + if (name && strcmp(name, c->map->consumer_dev_name) != 0) + continue; + chans[mapind].indio_dev = c->indio_dev; + chans[mapind].data = c->map->consumer_data; + chans[mapind].channel = + iio_chan_spec_from_name(chans[mapind].indio_dev, + c->map->adc_channel_label); + if (chans[mapind].channel == NULL) { + ret = -EINVAL; + goto error_free_chans; + } + iio_device_get(chans[mapind].indio_dev); + mapind++; + } + if (mapind == 0) { + ret = -ENODEV; + goto error_free_chans; + } + mutex_unlock(&iio_map_list_lock); + + return chans; + +error_free_chans: + for (i = 0; i < nummaps; i++) + iio_device_put(chans[i].indio_dev); + kfree(chans); +error_ret: + mutex_unlock(&iio_map_list_lock); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iio_channel_get_all); + +void iio_channel_release_all(struct iio_channel *channels) +{ + struct iio_channel *chan = &channels[0]; + + while (chan->indio_dev) { + iio_device_put(chan->indio_dev); + chan++; + } + kfree(channels); +} +EXPORT_SYMBOL_GPL(iio_channel_release_all); + +static void devm_iio_channel_free_all(struct device *dev, void *res) +{ + struct iio_channel *channels = *(struct iio_channel **)res; + + iio_channel_release_all(channels); +} + +struct iio_channel *devm_iio_channel_get_all(struct device *dev) +{ + struct iio_channel **ptr, *channels; + + ptr = devres_alloc(devm_iio_channel_free_all, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + channels = iio_channel_get_all(dev); + if (IS_ERR(channels)) { + devres_free(ptr); + return channels; + } + + *ptr = channels; + devres_add(dev, ptr); + + return channels; +} +EXPORT_SYMBOL_GPL(devm_iio_channel_get_all); + +void devm_iio_channel_release_all(struct device *dev, + struct iio_channel *channels) +{ + WARN_ON(devres_release(dev, devm_iio_channel_free_all, + devm_iio_channel_match, channels)); +} +EXPORT_SYMBOL_GPL(devm_iio_channel_release_all); + +static int iio_channel_read(struct iio_channel *chan, int *val, int *val2, + enum iio_chan_info_enum info) +{ + int unused; + int vals[INDIO_MAX_RAW_ELEMENTS]; + int ret; + int val_len = 2; + + if (val2 == NULL) + val2 = &unused; + + if (!iio_channel_has_info(chan->channel, info)) + return -EINVAL; + + if (chan->indio_dev->info->read_raw_multi) { + ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev, + chan->channel, INDIO_MAX_RAW_ELEMENTS, + vals, &val_len, info); + *val = vals[0]; + *val2 = vals[1]; + } else + ret = chan->indio_dev->info->read_raw(chan->indio_dev, + chan->channel, val, val2, info); + + return ret; +} + +int iio_read_channel_raw(struct iio_channel *chan, int *val) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_channel_raw); + +int iio_read_channel_average_raw(struct iio_channel *chan, int *val) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_channel_average_raw); + +static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan, + int raw, int *processed, unsigned int scale) +{ + int scale_type, scale_val, scale_val2; + int offset_type, offset_val, offset_val2; + s64 raw64 = raw; + + offset_type = iio_channel_read(chan, &offset_val, &offset_val2, + IIO_CHAN_INFO_OFFSET); + if (offset_type >= 0) { + switch (offset_type) { + case IIO_VAL_INT: + break; + case IIO_VAL_INT_PLUS_MICRO: + case IIO_VAL_INT_PLUS_NANO: + /* + * Both IIO_VAL_INT_PLUS_MICRO and IIO_VAL_INT_PLUS_NANO + * implicitely truncate the offset to it's integer form. + */ + break; + case IIO_VAL_FRACTIONAL: + offset_val /= offset_val2; + break; + case IIO_VAL_FRACTIONAL_LOG2: + offset_val >>= offset_val2; + break; + default: + return -EINVAL; + } + + raw64 += offset_val; + } + + scale_type = iio_channel_read(chan, &scale_val, &scale_val2, + IIO_CHAN_INFO_SCALE); + if (scale_type < 0) { + /* + * If no channel scaling is available apply consumer scale to + * raw value and return. + */ + *processed = raw * scale; + return 0; + } + + switch (scale_type) { + case IIO_VAL_INT: + *processed = raw64 * scale_val * scale; + break; + case IIO_VAL_INT_PLUS_MICRO: + if (scale_val2 < 0) + *processed = -raw64 * scale_val; + else + *processed = raw64 * scale_val; + *processed += div_s64(raw64 * (s64)scale_val2 * scale, + 1000000LL); + break; + case IIO_VAL_INT_PLUS_NANO: + if (scale_val2 < 0) + *processed = -raw64 * scale_val; + else + *processed = raw64 * scale_val; + *processed += div_s64(raw64 * (s64)scale_val2 * scale, + 1000000000LL); + break; + case IIO_VAL_FRACTIONAL: + *processed = div_s64(raw64 * (s64)scale_val * scale, + scale_val2); + break; + case IIO_VAL_FRACTIONAL_LOG2: + *processed = (raw64 * (s64)scale_val * scale) >> scale_val2; + break; + default: + return -EINVAL; + } + + return 0; +} + +int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, + int *processed, unsigned int scale) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed, + scale); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed); + +int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2, + enum iio_chan_info_enum attribute) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read(chan, val, val2, attribute); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_channel_attribute); + +int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2) +{ + return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET); +} +EXPORT_SYMBOL_GPL(iio_read_channel_offset); + +int iio_read_channel_processed(struct iio_channel *chan, int *val) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) { + ret = iio_channel_read(chan, val, NULL, + IIO_CHAN_INFO_PROCESSED); + } else { + ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); + if (ret < 0) + goto err_unlock; + ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1); + } + +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_channel_processed); + +int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2) +{ + return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE); +} +EXPORT_SYMBOL_GPL(iio_read_channel_scale); + +static int iio_channel_read_avail(struct iio_channel *chan, + const int **vals, int *type, int *length, + enum iio_chan_info_enum info) +{ + if (!iio_channel_has_available(chan->channel, info)) + return -EINVAL; + + return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel, + vals, type, length, info); +} + +int iio_read_avail_channel_raw(struct iio_channel *chan, + const int **vals, int *length) +{ + int ret; + int type; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (!chan->indio_dev->info) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read_avail(chan, + vals, &type, length, IIO_CHAN_INFO_RAW); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + if (ret >= 0 && type != IIO_VAL_INT) + /* raw values are assumed to be IIO_VAL_INT */ + ret = -EINVAL; + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw); + +static int iio_channel_read_max(struct iio_channel *chan, + int *val, int *val2, int *type, + enum iio_chan_info_enum info) +{ + int unused; + const int *vals; + int length; + int ret; + + if (!val2) + val2 = &unused; + + ret = iio_channel_read_avail(chan, &vals, type, &length, info); + switch (ret) { + case IIO_AVAIL_RANGE: + switch (*type) { + case IIO_VAL_INT: + *val = vals[2]; + break; + default: + *val = vals[4]; + *val2 = vals[5]; + } + return 0; + + case IIO_AVAIL_LIST: + if (length <= 0) + return -EINVAL; + switch (*type) { + case IIO_VAL_INT: + *val = vals[--length]; + while (length) { + if (vals[--length] > *val) + *val = vals[length]; + } + break; + default: + /* FIXME: learn about max for other iio values */ + return -EINVAL; + } + return 0; + + default: + return ret; + } +} + +int iio_read_max_channel_raw(struct iio_channel *chan, int *val) +{ + int ret; + int type; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (!chan->indio_dev->info) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_max_channel_raw); + +int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type) +{ + int ret = 0; + /* Need to verify underlying driver has not gone away */ + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + *type = chan->channel->type; +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_get_channel_type); + +static int iio_channel_write(struct iio_channel *chan, int val, int val2, + enum iio_chan_info_enum info) +{ + return chan->indio_dev->info->write_raw(chan->indio_dev, + chan->channel, val, val2, info); +} + +int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2, + enum iio_chan_info_enum attribute) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_write(chan, val, val2, attribute); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_write_channel_attribute); + +int iio_write_channel_raw(struct iio_channel *chan, int val) +{ + return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW); +} +EXPORT_SYMBOL_GPL(iio_write_channel_raw); + +unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan) +{ + const struct iio_chan_spec_ext_info *ext_info; + unsigned int i = 0; + + if (!chan->channel->ext_info) + return i; + + for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++) + ++i; + + return i; +} +EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count); + +static const struct iio_chan_spec_ext_info *iio_lookup_ext_info( + const struct iio_channel *chan, + const char *attr) +{ + const struct iio_chan_spec_ext_info *ext_info; + + if (!chan->channel->ext_info) + return NULL; + + for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) { + if (!strcmp(attr, ext_info->name)) + return ext_info; + } + + return NULL; +} + +ssize_t iio_read_channel_ext_info(struct iio_channel *chan, + const char *attr, char *buf) +{ + const struct iio_chan_spec_ext_info *ext_info; + + ext_info = iio_lookup_ext_info(chan, attr); + if (!ext_info) + return -EINVAL; + + return ext_info->read(chan->indio_dev, ext_info->private, + chan->channel, buf); +} +EXPORT_SYMBOL_GPL(iio_read_channel_ext_info); + +ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr, + const char *buf, size_t len) +{ + const struct iio_chan_spec_ext_info *ext_info; + + ext_info = iio_lookup_ext_info(chan, attr); + if (!ext_info) + return -EINVAL; + + return ext_info->write(chan->indio_dev, ext_info->private, + chan->channel, buf, len); +} +EXPORT_SYMBOL_GPL(iio_write_channel_ext_info); |