linux-kernel - [PATCH v8 08/10] cpufreq: dt: Validate all interconnect paths

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Message-Id: <20200512125327.1868-9-georgi.djakov@linaro.org>
Date:   Tue, 12 May 2020 15:53:25 +0300
From:   Georgi Djakov <georgi.djakov@...aro.org>
To:     vireshk@...nel.org, nm@...com, sboyd@...nel.org, rjw@...ysocki.net,
        saravanak@...gle.com, sibis@...eaurora.org, mka@...omium.org
Cc:     robh+dt@...nel.org, rnayak@...eaurora.org,
        bjorn.andersson@...aro.org, vincent.guittot@...aro.org,
        jcrouse@...eaurora.org, evgreen@...omium.org,
        linux-pm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, georgi.djakov@...aro.org
Subject: [PATCH v8 08/10] cpufreq: dt: Validate all interconnect paths

Currently when we check for the available resources, we assume that there
is only one interconnect path, but in fact it could be more than one. Do
some validation to determine the number of paths and verify if each one
of them is available.

Signed-off-by: Georgi Djakov <georgi.djakov@...aro.org>
---
v8:
* New patch.

 drivers/cpufreq/cpufreq-dt.c | 49 ++++++++++++++++++++++++++++++++----
 1 file changed, 44 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 4ecef3257532..3dd28c2c1633 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -91,12 +91,54 @@ static const char *find_supply_name(struct device *dev)
 	return name;
 }
 
+static int find_icc_paths(struct device *dev)
+{
+	struct device_node *np;
+	struct icc_path **paths;
+	int i, count, num_paths;
+	int ret = 0;
+
+	np = of_node_get(dev->of_node);
+	if (!np)
+		return 0;
+
+	count = of_count_phandle_with_args(np, "interconnects",
+					   "#interconnect-cells");
+	of_node_put(np);
+	if (count < 0)
+		return 0;
+
+	/* two phandles when #interconnect-cells = <1> */
+	if (count % 2) {
+		dev_err(dev, "%s: Invalid interconnects values\n", __func__);
+		return -EINVAL;
+	}
+
+	num_paths = count / 2;
+	paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
+	if (!paths)
+		return -ENOMEM;
+
+	for (i = 0; i < num_paths; i++) {
+		paths[i] = of_icc_get_by_index(dev, i);
+		ret = PTR_ERR_OR_ZERO(paths[i]);
+		if (ret)
+			break;
+	}
+
+	while (i--)
+		icc_put(paths[i]);
+
+	kfree(paths);
+
+	return ret;
+}
+
 static int resources_available(void)
 {
 	struct device *cpu_dev;
 	struct regulator *cpu_reg;
 	struct clk *cpu_clk;
-	struct icc_path *cpu_path;
 	int ret = 0;
 	const char *name;
 
@@ -123,8 +165,7 @@ static int resources_available(void)
 
 	clk_put(cpu_clk);
 
-	cpu_path = of_icc_get(cpu_dev, NULL);
-	ret = PTR_ERR_OR_ZERO(cpu_path);
+	ret = find_icc_paths(cpu_dev);
 	if (ret) {
 		if (ret == -EPROBE_DEFER)
 			dev_dbg(cpu_dev, "defer icc path: %d\n", ret);
@@ -134,8 +175,6 @@ static int resources_available(void)
 		return ret;
 	}
 
-	icc_put(cpu_path);
-
 	name = find_supply_name(cpu_dev);
 	/* Platform doesn't require regulator */
 	if (!name)