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| author | Ivan T. Ivanov <iivanov@mm-sol.com> | 2014-10-22 18:29:43 +0300 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2014-10-25 11:03:40 +0100 |
| commit | acd8256723f286b7217801fbed24503f8565b91e (patch) | |
| tree | 1cde7b390ee2e9afb3981a0c6368b6f9042ebcc3 | |
| parent | a9bef750135cc261bfceff6840a30a3f357df8da (diff) | |
| download | linux-stable-acd8256723f286b7217801fbed24503f8565b91e.tar.gz linux-stable-acd8256723f286b7217801fbed24503f8565b91e.tar.bz2 linux-stable-acd8256723f286b7217801fbed24503f8565b91e.zip | |
iio: inkern: Add of_xlate function to struct iio_info
When #iio-cells is greater than '0', the driver could provide
a custom of_xlate function that reads the *args* and returns
the appropriate index in registered IIO channels array.
Add simple translation function, suitable for the most 1:1
mapped channels in IIO chips, and use it when driver did not
provide custom implementation.
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
| -rw-r--r-- | drivers/iio/inkern.c | 33 | ||||
| -rw-r--r-- | include/linux/iio/iio.h | 8 |
2 files changed, 36 insertions, 5 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index c7497009d60a..0cc505d98686 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -100,6 +100,28 @@ 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) + return -EINVAL; + + return iiospec->args[0]; +} + static int __of_iio_channel_get(struct iio_channel *channel, struct device_node *np, int index) { @@ -122,18 +144,19 @@ static int __of_iio_channel_get(struct iio_channel *channel, 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) { - err = -EINVAL; + 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 err; + return index; } static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 15dc6bc2bdd2..3642ce7ef512 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -13,6 +13,7 @@ #include <linux/device.h> #include <linux/cdev.h> #include <linux/iio/types.h> +#include <linux/of.h> /* IIO TODO LIST */ /* * Provide means of adjusting timer accuracy. @@ -326,6 +327,11 @@ struct iio_dev; * @update_scan_mode: function to configure device and scan buffer when * channels have changed * @debugfs_reg_access: function to read or write register value of device + * @of_xlate: function pointer to obtain channel specifier index. + * When #iio-cells is greater than '0', the driver could + * provide a custom of_xlate function that reads the + * *args* and returns the appropriate index in registered + * IIO channels array. **/ struct iio_info { struct module *driver_module; @@ -385,6 +391,8 @@ struct iio_info { int (*debugfs_reg_access)(struct iio_dev *indio_dev, unsigned reg, unsigned writeval, unsigned *readval); + int (*of_xlate)(struct iio_dev *indio_dev, + const struct of_phandle_args *iiospec); }; /** |