linux-kernel - [PATCH v4 02/12] thermal/of: Replace device node match with device node search

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Date:   Sun, 10 Jul 2022 00:32:19 +0200
From:   Daniel Lezcano <daniel.lezcano@...exp.org>
To:     daniel.lezcano@...aro.org, rafael@...nel.org
Cc:     rui.zhang@...el.com, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, khilman@...libre.com,
        abailon@...libre.com, lukasz.luba@....com,
        Amit Kucheria <amitk@...nel.org>
Subject: [PATCH v4 02/12] thermal/of: Replace device node match with device node search

The thermal_of code builds a trip array associated with the node
pointer in order to compare the trip point phandle with the list.

The thermal trip is a thermal zone property and should be moved
there. If some sensors have hardcoded trip points, they should use the
exported structure instead of redefining again and again their own
structure and data to describe exactly the same things.

In order to move this to the thermal.h header and allow more cleanup,
we need to remove the node pointer from the structure.

Instead of building storing the device node, we search directly in the
device tree the corresponding node. That results in a simplification
of the code and allows to move the structure to thermal.h

Cc: Alexandre Bailon <abailon@...libre.com>
Cc: Kevin Hilman <khilman@...libre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@...exp.org>
---
 drivers/thermal/thermal_of.c | 64 +++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
index b65d435cb92f..7d96494ef94d 100644
--- a/drivers/thermal/thermal_of.c
+++ b/drivers/thermal/thermal_of.c
@@ -671,6 +671,35 @@ EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
 
 /***   functions parsing device tree nodes   ***/
 
+static int of_find_trip_id(struct device_node *np, struct device_node *trip)
+{
+	struct device_node *trips;
+	struct device_node *t;
+	int i = 0;
+
+	trips = of_get_child_by_name(np, "trips");
+	if (!trips) {
+		pr_err("Failed to find 'trips' node\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Find the trip id point associated with the cooling device map
+	 */
+	for_each_child_of_node(trips, t) {
+
+		if (t == trip)
+			goto out;
+		i++;
+	}
+
+	i = -ENXIO;
+out:	
+	of_node_put(trips);
+
+	return i;
+}
+
 /**
  * thermal_of_populate_bind_params - parse and fill cooling map data
  * @np: DT node containing a cooling-map node
@@ -686,14 +715,13 @@ EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
  * Return: 0 on success, proper error code otherwise
  */
 static int thermal_of_populate_bind_params(struct device_node *np,
-					   struct __thermal_bind_params *__tbp,
-					   struct thermal_trip *trips,
-					   int ntrips)
+					   struct __thermal_bind_params *__tbp)
 {
 	struct of_phandle_args cooling_spec;
 	struct __thermal_cooling_bind_param *__tcbp;
 	struct device_node *trip;
 	int ret, i, count;
+	int trip_id;
 	u32 prop;
 
 	/* Default weight. Usage is optional */
@@ -708,18 +736,14 @@ static int thermal_of_populate_bind_params(struct device_node *np,
 		return -ENODEV;
 	}
 
-	/* match using device_node */
-	for (i = 0; i < ntrips; i++)
-		if (trip == trips[i].np) {
-			__tbp->trip_id = i;
-			break;
-		}
-
-	if (i == ntrips) {
-		ret = -ENODEV;
+	trip_id = of_find_trip_id(np, trip);
+	if (trip_id < 0) {
+		ret = trip_id;
 		goto end;
 	}
 
+	__tbp->trip_id = trip_id;
+	
 	count = of_count_phandle_with_args(np, "cooling-device",
 					   "#cooling-cells");
 	if (count <= 0) {
@@ -868,6 +892,7 @@ static struct __thermal_zone
 __init *thermal_of_build_thermal_zone(struct device_node *np)
 {
 	struct device_node *child = NULL, *gchild;
+	struct device_node *trips;
 	struct __thermal_zone *tz;
 	int ret, i;
 	u32 prop, coef[2];
@@ -910,13 +935,13 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 	}
 
 	/* trips */
-	child = of_get_child_by_name(np, "trips");
+	trips = of_get_child_by_name(np, "trips");
 
 	/* No trips provided */
-	if (!child)
+	if (!trips)
 		goto finish;
 
-	tz->ntrips = of_get_child_count(child);
+	tz->ntrips = of_get_child_count(trips);
 	if (tz->ntrips == 0) /* must have at least one child */
 		goto finish;
 
@@ -927,14 +952,12 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 	}
 
 	i = 0;
-	for_each_child_of_node(child, gchild) {
+	for_each_child_of_node(trips, gchild) {
 		ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
 		if (ret)
 			goto free_trips;
 	}
 
-	of_node_put(child);
-
 	/* cooling-maps */
 	child = of_get_child_by_name(np, "cooling-maps");
 
@@ -954,13 +977,13 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 
 	i = 0;
 	for_each_child_of_node(child, gchild) {
-		ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
-						      tz->trips, tz->ntrips);
+		ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++]);
 		if (ret)
 			goto free_tbps;
 	}
 
 finish:
+	of_node_put(trips);
 	of_node_put(child);
 
 	return tz;
@@ -981,6 +1004,7 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 	for (i = 0; i < tz->ntrips; i++)
 		of_node_put(tz->trips[i].np);
 	kfree(tz->trips);
+	of_node_put(trips);
 	of_node_put(gchild);
 free_tz:
 	kfree(tz);
-- 
2.25.1