diff options
Diffstat (limited to 'drivers/iio/inkern.c')
| -rw-r--r-- | drivers/iio/inkern.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index b289915b846..795d100b4c3 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -10,6 +10,7 @@ #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" @@ -92,6 +93,164 @@ static const struct iio_chan_spec 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; +} + +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; + index = iiospec.args_count ? iiospec.args[0] : 0; + if (index >= indio_dev->num_channels) { + return -EINVAL; + goto err_put; + } + channel->channel = &indio_dev->channels[index]; + + return 0; + +err_put: + iio_device_put(indio_dev); + return err; +} + +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)) + break; + else if (name && index >= 0) { + pr_err("ERROR: could not get IIO channel %s:%s(%i)\n", + np->full_name, name ? name : "", index); + return chan; + } + + /* + * 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)) + break; + } + 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) @@ -150,7 +309,14 @@ 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); @@ -173,6 +339,11 @@ struct iio_channel *iio_channel_get_all(struct device *dev) 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); |