On Sun, Aug 17, 2014 at 01:54:16PM +0100, Grant Likely wrote:

On Sun, 17 Aug 2014 09:04:14 +0300, Mika Westerberg [off-list ref] wrote:

quoted

From: Aaron Lu <redacted>

With the unified device properties interface in place, add device tree support.
By adding the dev_prop_ops for of_node devices, drivers can access properties
from ACPI or Device Tree in a generic way.

Signed-off-by: Aaron Lu <redacted>
Reviewed-by: Darren Hart <redacted>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Hi Mika,

As commented on patch 3, the new API currently throws away type
information so the compiler won't warn on an error. That needs to be
fixed and this patch reworked accordingly.

The compiler should warn when we add static inline property accessor
functions for each type.

g.

---

quoted

 drivers/of/base.c        | 194 ++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/of/platform.c    |   4 +-
 include/linux/property.h |   4 +
 3 files changed, 200 insertions(+), 2 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index b9864806e9b8..527004d01423 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c

@@ -20,7 +20,7 @@
 #include <linux/ctype.h>
 #include <linux/cpu.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/property.h>
 #include <linux/of_graph.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>

@@ -1343,6 +1343,39 @@ int of_property_read_u64(const struct device_node *np, const char *propname,
 EXPORT_SYMBOL_GPL(of_property_read_u64);
 
 /**
+ * of_property_read_u64_array - Find and read an array of 64 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_values,
+			       size_t sz)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--) {
+		*out_values++ = of_read_number(val, 2);
+		val += 2;
+	};
+	return 0;
+}

Considering we don't even have a user of u64 arrays in all of the DT
drivers, do we even need this type hook in the generic API?

Indeed, I think we can remove it for now.