diff options
Diffstat (limited to 'drivers/iio/inkern.c')
-rw-r--r-- | drivers/iio/inkern.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c new file mode 100644 index 00000000000..922645893dc --- /dev/null +++ b/drivers/iio/inkern.c @@ -0,0 +1,293 @@ +/* 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/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(&mapi->l, &iio_map_list); + i++; + } +error_ret: + mutex_unlock(&iio_map_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_map_array_register); + + +/* Assumes the exact same array (e.g. memory locations) + * used at unregistration as used at registration rather than + * more complex checking of contents. + */ +int iio_map_array_unregister(struct iio_dev *indio_dev, + struct iio_map *maps) +{ + int i = 0, ret = 0; + bool found_it; + struct iio_map_internal *mapi; + + if (maps == NULL) + return 0; + + mutex_lock(&iio_map_list_lock); + while (maps[i].consumer_dev_name != NULL) { + found_it = false; + list_for_each_entry(mapi, &iio_map_list, l) + if (&maps[i] == mapi->map) { + list_del(&mapi->l); + kfree(mapi); + found_it = true; + break; + } + if (found_it == false) { + ret = -ENODEV; + goto error_ret; + } + i++; + } +error_ret: + 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; +} + + +struct iio_channel *iio_st_channel_get(const char *name, + const char *channel_name) +{ + struct iio_map_internal *c_i = NULL, *c = NULL; + struct iio_channel *channel; + + 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; + get_device(&c->indio_dev->dev); + break; + } + mutex_unlock(&iio_map_list_lock); + if (c == NULL) + return ERR_PTR(-ENODEV); + + channel = kmalloc(sizeof(*channel), GFP_KERNEL); + if (channel == NULL) + return ERR_PTR(-ENOMEM); + + 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); + + return channel; +} +EXPORT_SYMBOL_GPL(iio_st_channel_get); + +void iio_st_channel_release(struct iio_channel *channel) +{ + put_device(&channel->indio_dev->dev); + kfree(channel); +} +EXPORT_SYMBOL_GPL(iio_st_channel_release); + +struct iio_channel *iio_st_channel_get_all(const char *name) +{ + struct iio_channel *chans; + struct iio_map_internal *c = NULL; + int nummaps = 0; + int mapind = 0; + int i, ret; + + if (name == NULL) + return ERR_PTR(-EINVAL); + + 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 = kzalloc(sizeof(*chans)*(nummaps + 1), 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].channel = + iio_chan_spec_from_name(chans[mapind].indio_dev, + c->map->adc_channel_label); + if (chans[mapind].channel == NULL) { + ret = -EINVAL; + put_device(&chans[mapind].indio_dev->dev); + goto error_free_chans; + } + get_device(&chans[mapind].indio_dev->dev); + mapind++; + } + mutex_unlock(&iio_map_list_lock); + if (mapind == 0) { + ret = -ENODEV; + goto error_free_chans; + } + return chans; + +error_free_chans: + for (i = 0; i < nummaps; i++) + if (chans[i].indio_dev) + put_device(&chans[i].indio_dev->dev); + kfree(chans); +error_ret: + mutex_unlock(&iio_map_list_lock); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iio_st_channel_get_all); + +void iio_st_channel_release_all(struct iio_channel *channels) +{ + struct iio_channel *chan = &channels[0]; + + while (chan->indio_dev) { + put_device(&chan->indio_dev->dev); + chan++; + } + kfree(channels); +} +EXPORT_SYMBOL_GPL(iio_st_channel_release_all); + +int iio_st_read_channel_raw(struct iio_channel *chan, int *val) +{ + int val2, ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel, + val, &val2, 0); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_st_read_channel_raw); + +int iio_st_read_channel_scale(struct iio_channel *chan, int *val, int *val2) +{ + int ret; + + mutex_lock(&chan->indio_dev->info_exist_lock); + if (chan->indio_dev->info == NULL) { + ret = -ENODEV; + goto err_unlock; + } + + ret = chan->indio_dev->info->read_raw(chan->indio_dev, + chan->channel, + val, val2, + IIO_CHAN_INFO_SCALE); +err_unlock: + mutex_unlock(&chan->indio_dev->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_st_read_channel_scale); + +int iio_st_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_st_get_channel_type); |