iio: inkern: move to fwnode properties

This moves the IIO in kernel interface to use fwnode properties and thus
be firmware agnostic.

Note that the interface is still not firmware agnostic. At this point we
have both OF and fwnode interfaces so that we don't break any user. On
top of this we also want to have a per driver conversion and that is the
main reason we have both of_xlate() and fwnode_xlate() support.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220715122903.332535-6-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 83 insertions, 74 deletions

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 9e0c7cc3a093..9cfa66ef9536 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -5,6 +5,7 @@
  */
 #include <linux/err.h>
 #include <linux/export.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -117,15 +118,8 @@ static const struct iio_chan_spec
 	return chan;
 }
 
-#ifdef CONFIG_OF
-
-static int iio_dev_node_match(struct device *dev, const void *data)
-{
-	return dev->of_node == data && dev->type == &iio_device_type;
-}
-
 /**
- * __of_iio_simple_xlate - translate iiospec to the IIO channel index
+ * __fwnode_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
  *
@@ -134,14 +128,14 @@ static int iio_dev_node_match(struct device *dev, const void *data)
  * 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)
+static int __fwnode_iio_simple_xlate(struct iio_dev *indio_dev,
+				     const struct fwnode_reference_args *iiospec)
 {
-	if (!iiospec->args_count)
+	if (!iiospec->nargs)
 		return 0;
 
 	if (iiospec->args[0] >= indio_dev->num_channels) {
-		dev_err(&indio_dev->dev, "invalid channel index %u\n",
+		dev_err(&indio_dev->dev, "invalid channel index %llu\n",
 			iiospec->args[0]);
 		return -EINVAL;
 	}
@@ -149,34 +143,55 @@ static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
 	return iiospec->args[0];
 }
 
-static int __of_iio_channel_get(struct iio_channel *channel,
-				struct device_node *np, int index)
+/*
+ * Simple helper to copy fwnode_reference_args into of_phandle_args so we
+ * can pass it to of_xlate(). Ultimate goal is to drop this together with
+ * of_xlate().
+ */
+static int __fwnode_to_of_xlate(struct iio_dev *indio_dev,
+				const struct fwnode_reference_args *iiospec)
 {
+	struct of_phandle_args of_args;
+	unsigned int i;
+
+	of_args.args_count = iiospec->nargs;
+	of_args.np = to_of_node(iiospec->fwnode);
+
+	for (i = 0; i < MAX_PHANDLE_ARGS; i++)
+		of_args.args[i] = i < iiospec->nargs ? iiospec->args[i] : 0;
+
+	return indio_dev->info->of_xlate(indio_dev, &of_args);
+}
+
+static int __fwnode_iio_channel_get(struct iio_channel *channel,
+				    struct fwnode_handle *fwnode, int index)
+{
+	struct fwnode_reference_args iiospec;
 	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);
+	err = fwnode_property_get_reference_args(fwnode, "io-channels",
+						 "#io-channel-cells", 0,
+						 index, &iiospec);
 	if (err)
 		return err;
 
-	idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
-			       iio_dev_node_match);
+	idev = bus_find_device_by_fwnode(&iio_bus_type, iiospec.fwnode);
 	if (idev == NULL) {
-		of_node_put(iiospec.np);
+		fwnode_handle_put(iiospec.fwnode);
 		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);
+		index = __fwnode_to_of_xlate(indio_dev, &iiospec);
+	else if (indio_dev->info->fwnode_xlate)
+		index = indio_dev->info->fwnode_xlate(indio_dev, &iiospec);
 	else
-		index = __of_iio_simple_xlate(indio_dev, &iiospec);
-	of_node_put(iiospec.np);
+		index = __fwnode_iio_simple_xlate(indio_dev, &iiospec);
+	fwnode_handle_put(iiospec.fwnode);
 	if (index < 0)
 		goto err_put;
 	channel->channel = &indio_dev->channels[index];
@@ -188,7 +203,8 @@ err_put:
 	return index;
 }
 
-static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
+static struct iio_channel *fwnode_iio_channel_get(struct fwnode_handle *fwnode,
+						  int index)
 {
 	struct iio_channel *channel;
 	int err;
@@ -200,7 +216,7 @@ static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
 	if (channel == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	err = __of_iio_channel_get(channel, np, index);
+	err = __fwnode_iio_channel_get(channel, fwnode, index);
 	if (err)
 		goto err_free_channel;
 
@@ -211,8 +227,8 @@ err_free_channel:
 	return ERR_PTR(err);
 }
 
-static struct iio_channel *__of_iio_channel_get_by_name(struct device_node *np,
-							const char *name)
+static struct iio_channel *
+__fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode, const char *name)
 {
 	struct iio_channel *chan;
 	int index = 0;
@@ -220,19 +236,20 @@ static struct iio_channel *__of_iio_channel_get_by_name(struct device_node *np,
 	/*
 	 * 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()
+	 * index will be an error code, and fwnode_iio_channel_get()
 	 * will fail.
 	 */
 	if (name)
-		index = of_property_match_string(np, "io-channel-names", name);
+		index = fwnode_property_match_string(fwnode, "io-channel-names",
+						     name);
 
-	chan = of_iio_channel_get(np, index);
+	chan = fwnode_iio_channel_get(fwnode, index);
 	if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
 		return chan;
 	if (name) {
 		if (index >= 0) {
-			pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
-			       np, name, index);
+			pr_err("ERROR: could not get IIO channel %pfw:%s(%i)\n",
+			       fwnode, name, index);
 			/*
 			 * In this case, we found 'name' in 'io-channel-names'
 			 * but somehow we still fail so that we should not proceed
@@ -243,16 +260,16 @@ static struct iio_channel *__of_iio_channel_get_by_name(struct device_node *np,
 			return ERR_PTR(-EINVAL);
 		}
 		/*
-		 * If index < 0, then of_parse_phandle_with_args() fails
-		 * with -EINVAL which is expected. We should not proceed
-		 * if we get any other error.
+		 * If index < 0, then fwnode_property_get_reference_args() fails
+		 * with -EINVAL or -ENOENT (ACPI case) which is expected. We
+		 * should not proceed if we get any other error.
 		 */
-		if (PTR_ERR(chan) != -EINVAL)
+		if (PTR_ERR(chan) != -EINVAL && PTR_ERR(chan) != -ENOENT)
 			return chan;
 	} else if (PTR_ERR(chan) != -ENOENT) {
 		/*
 		 * if !name, then we should only proceed the lookup if
-		 * of_parse_phandle_with_args() returns -ENOENT.
+		 * fwnode_property_get_reference_args() returns -ENOENT.
 		 */
 		return chan;
 	}
@@ -261,13 +278,14 @@ static struct iio_channel *__of_iio_channel_get_by_name(struct device_node *np,
 	return ERR_PTR(-ENODEV);
 }
 
-struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
-					       const char *name)
+struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
+						   const char *name)
 {
+	struct fwnode_handle *parent;
 	struct iio_channel *chan;
 
 	/* Walk up the tree of devices looking for a matching iio channel */
-	chan = __of_iio_channel_get_by_name(np, name);
+	chan = __fwnode_iio_channel_get_by_name(fwnode, name);
 	if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV)
 		return chan;
 
@@ -276,33 +294,34 @@ struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
 	 * If the parent node has a "io-channel-ranges" property,
 	 * then we can try one of its channels.
 	 */
-	np = np->parent;
-	while (np) {
-		if (!of_get_property(np, "io-channel-ranges", NULL))
+	fwnode_for_each_parent_node(fwnode, parent) {
+		if (!fwnode_property_present(parent, "io-channel-ranges")) {
+			fwnode_handle_put(parent);
 			return ERR_PTR(-ENODEV);
+		}
 
-		chan = __of_iio_channel_get_by_name(np, name);
-		if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV)
+		chan = __fwnode_iio_channel_get_by_name(fwnode, name);
+		if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV) {
+			fwnode_handle_put(parent);
  			return chan;
-
-		np = np->parent;
+		}
 	}
 
 	return ERR_PTR(-ENODEV);
 }
-EXPORT_SYMBOL_GPL(of_iio_channel_get_by_name);
+EXPORT_SYMBOL_GPL(fwnode_iio_channel_get_by_name);
 
-static struct iio_channel *of_iio_channel_get_all(struct device *dev)
+static struct iio_channel *fwnode_iio_channel_get_all(struct device *dev)
 {
+	struct fwnode_handle *fwnode = dev_fwnode(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);
+		ret = fwnode_property_get_reference_args(fwnode, "io-channels",
+							 "#io-channel-cells", 0,
+							 nummaps, NULL);
 		if (ret < 0)
 			break;
 	} while (++nummaps);
@@ -315,10 +334,9 @@ static struct iio_channel *of_iio_channel_get_all(struct device *dev)
 	if (chans == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	/* Search for OF matches */
+	/* Search for FW matches */
 	for (mapind = 0; mapind < nummaps; mapind++) {
-		ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
-					   mapind);
+		ret = __fwnode_iio_channel_get(&chans[mapind], fwnode, mapind);
 		if (ret)
 			goto error_free_chans;
 	}
@@ -331,15 +349,6 @@ error_free_chans:
 	return ERR_PTR(ret);
 }
 
-#else /* CONFIG_OF */
-
-static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-#endif /* CONFIG_OF */
-
 static struct iio_channel *iio_channel_get_sys(const char *name,
 					       const char *channel_name)
 {
@@ -400,8 +409,8 @@ struct iio_channel *iio_channel_get(struct device *dev,
 	struct iio_channel *channel;
 
 	if (dev) {
-		channel = of_iio_channel_get_by_name(dev->of_node,
-						     channel_name);
+		channel = fwnode_iio_channel_get_by_name(dev_fwnode(dev),
+							 channel_name);
 		if (!IS_ERR(channel) || PTR_ERR(channel) != -ENODEV)
 			return channel;
 	}
@@ -442,14 +451,14 @@ struct iio_channel *devm_iio_channel_get(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_iio_channel_get);
 
-struct iio_channel *devm_of_iio_channel_get_by_name(struct device *dev,
-						    struct device_node *np,
-						    const char *channel_name)
+struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
+							struct fwnode_handle *fwnode,
+							const char *channel_name)
 {
 	struct iio_channel *channel;
 	int ret;
 
-	channel = of_iio_channel_get_by_name(np, channel_name);
+	channel = fwnode_iio_channel_get_by_name(fwnode, channel_name);
 	if (IS_ERR(channel))
 		return channel;
 
@@ -459,7 +468,7 @@ struct iio_channel *devm_of_iio_channel_get_by_name(struct device *dev,
 
 	return channel;
 }
-EXPORT_SYMBOL_GPL(devm_of_iio_channel_get_by_name);
+EXPORT_SYMBOL_GPL(devm_fwnode_iio_channel_get_by_name);
 
 struct iio_channel *iio_channel_get_all(struct device *dev)
 {
@@ -473,7 +482,7 @@ struct iio_channel *iio_channel_get_all(struct device *dev)
 	if (dev == NULL)
 		return ERR_PTR(-EINVAL);
 
-	chans = of_iio_channel_get_all(dev);
+	chans = fwnode_iio_channel_get_all(dev);
 	/*
 	 * We only want to carry on if the error is -ENODEV.  Anything else
 	 * should be reported up the stack.