iio: core: Add devm_ APIs for iio_channel_{get,release}_all

Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get_all() and release it by calling
iio_channel_release_all().

Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get_all() then it need not to release it
explicitly, it can be done by managed device framework when driver
get un-binded.

This reduces the code in error path and also need of .remove callback in
some cases.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 9fd8934c1887..c4757e6367e7 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -489,6 +489,42 @@ void iio_channel_release_all(struct iio_channel *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)
 {