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From:   Naresh Solanki <naresh.solanki@9elements.com>
To:     zev@bewilderbeest.net, Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>
Cc:     Naresh Solanki <Naresh.Solanki@9elements.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] regulator: userspace-consumer: Support multiple supplies in DT
Date:   Thu, 20 Apr 2023 21:24:02 +0200
Message-Id: <20230420192402.3695265-2-Naresh.Solanki@9elements.com>
In-Reply-To: <20230420192402.3695265-1-Naresh.Solanki@9elements.com>
References: <20230420192402.3695265-1-Naresh.Solanki@9elements.com>
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Add support for optional DT property 'regulator-supplies' to handle
connectors with multiple supplies.

If this property is present, it will determine all regulator supplies.
Otherwise, the 'vout' supply will be used as a fallback.

This change improves support for some connector output like PCIe
connectors on mainboards that can be powered by 12V and 3.3V supplies.

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
...
Change in V2:
- Update commit message
- Code improved to add fallback if the property isn't used.
---
 drivers/regulator/userspace-consumer.c | 33 +++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c
index 97f075ed68c9..aaa0189d6dab 100644
--- a/drivers/regulator/userspace-consumer.c
+++ b/drivers/regulator/userspace-consumer.c
@@ -120,7 +120,10 @@ static int regulator_userspace_consumer_probe(struct platform_device *pdev)
 	struct regulator_userspace_consumer_data tmpdata;
 	struct regulator_userspace_consumer_data *pdata;
 	struct userspace_consumer_data *drvdata;
-	int ret;
+	struct device_node *np = pdev->dev.of_node;
+	struct property *prop;
+	const char *supply;
+	int ret, count = 0;
 
 	pdata = dev_get_platdata(&pdev->dev);
 	if (!pdata) {
@@ -131,11 +134,29 @@ static int regulator_userspace_consumer_probe(struct platform_device *pdev)
 		memset(pdata, 0, sizeof(*pdata));
 
 		pdata->no_autoswitch = true;
-		pdata->num_supplies = 1;
-		pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);
-		if (!pdata->supplies)
-			return -ENOMEM;
-		pdata->supplies[0].supply = "vout";
+
+		if (of_find_property(np, "regulator-supplies", NULL)) {
+			pdata->num_supplies = of_property_count_strings(np, "regulator-supplies");
+			if (pdata->num_supplies < 1) {
+				dev_err(&pdev->dev,
+					"could not parse property regulator-supplies\n");
+				return -EINVAL;
+			}
+			pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies) *
+						       pdata->num_supplies, GFP_KERNEL);
+			if (!pdata->supplies)
+				return -ENOMEM;
+			of_property_for_each_string(np, "regulator-supplies", prop, supply) {
+				pdata->supplies[count++].supply = supply;
+			}
+		} else {
+			pdata->num_supplies = 1;
+			pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies),
+						       GFP_KERNEL);
+			if (!pdata->supplies)
+				return -ENOMEM;
+			pdata->supplies[0].supply = "vout";
+		}
 	}
 
 	if (pdata->num_supplies < 1) {
-- 
2.39.1