Re: [PATCH 3/6] dt-bindings: net: Add documentation for phy-supply

LABBE Corentin
2022-05-11T08:03:09Z

Le Mon, May 09, 2022 at 05:56:34PM +0100, Mark Brown a écrit :
> On Mon, May 09, 2022 at 06:38:05PM +0200, Andrew Lunn wrote:
>
> > So we have a collection of regulators, varying in numbers between
> > different PHYs, with different vendor names and purposes. In general,
> > they all should be turned on. Yet we want them named so it is clear
> > what is going on.
>
> > Is there a generic solution here so that the phylib core can somehow
> > enumerate them and turn them on, without actually knowing what they
> > are called because they have vendor specific names in order to be
> > clear what they are?
>
> > There must be a solution to this, phylib cannot be the first subsystem
> > to have this requirement, so if you could point to an example, that
> > would be great.
>
> No, it's not really come up much before - generally things with
> regulator control that have generic drivers tend not to be sophisticated
> enough to have more than one supply, or to be on an enumerable bus where
> the power is part of the bus specification so have the power specified
> as part of the bus. You'd need to extend the regulator bindings to
> support parallel array of phandles and array of names properties like
> clocks have as an option like you were asking for, which would doubtless
> be fun for validation but is probably the thing here.

Does you mean something like this:
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 1e54a833f2cf..404f5b874b59 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -351,6 +351,32 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
mutex_unlock(&regulator_list_mutex);
}

+/**
+ * of_get_regulator_from_list - get a regulator device node based on supply name
+ * from a DT regulators list
+ * @dev: Device pointer for the consumer (of regulator) device
+ * @supply: regulator supply name
+ *
+ * Extract the regulator device node corresponding to the supply name.
+ * returns the device node corresponding to the regulator if found, else
+ * returns NULL.
+ */
+static struct device_node *of_get_regulator_from_list(struct device *dev,
+ struct device_node *np,
+ const char *supply)
+{
+ int index, ret;
+ struct of_phandle_args regspec;
+
+ index = of_property_match_string(np, "regulator-names", supply);
+ if (index >= 0) {
+ ret = of_parse_phandle_with_args(np, "regulators", NULL, index, &regspec);
+ if (ret == 0)
+ return regspec.np;
+ }
+ return NULL;
+}
+
/**
* of_get_child_regulator - get a child regulator device node
* based on supply name
@@ -362,17 +388,23 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
* returns the device node corresponding to the regulator if found, else
* returns NULL.
*/
-static struct device_node *of_get_child_regulator(struct device_node *parent,
- const char *prop_name)
+static struct device_node *of_get_child_regulator(struct device *dev,
+ struct device_node *parent,
+ const char *supply)
{
struct device_node *regnode = NULL;
struct device_node *child = NULL;
+ char prop_name[64]; /* 64 is max size of property name */

+ snprintf(prop_name, 64, "%s-supply", supply);
for_each_child_of_node(parent, child) {
+ regnode = of_get_regulator_from_list(dev, child, supply);
+ if (regnode)
+ return regnode;
regnode = of_parse_phandle(child, prop_name, 0);

if (!regnode) {
- regnode = of_get_child_regulator(child, prop_name);
+ regnode = of_get_child_regulator(dev, child, prop_name);
if (regnode)
goto err_node_put;
} else {
@@ -401,12 +433,15 @@ static struct device_node *of_get_regulator(struct device *dev, const char *supp
char prop_name[64]; /* 64 is max size of property name */

dev_dbg(dev, "Looking up %s-supply from device tree\n", supply);
+ regnode = of_get_regulator_from_list(dev, dev->of_node, supply);
+ if (regnode)
+ return regnode;

snprintf(prop_name, 64, "%s-supply", supply);
regnode = of_parse_phandle(dev->of_node, prop_name, 0);

if (!regnode) {
- regnode = of_get_child_regulator(dev->of_node, prop_name);
+ regnode = of_get_child_regulator(dev, dev->of_node, supply);
if (regnode)
return regnode;

And then for our case, a regulator_get_bulk will be needed.
Does I well understood what you mean ?