netdev - [PATCH v3 2/2] NFC: nxp-nci: Add pad supply voltage pvdd-supply

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Date: Fri, 09 Jun 2023 18:33:00 +0000
From: Raymond Hackley <raymondhackley@...tonmail.com>
To: linux-kernel@...r.kernel.org
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>, "David S . Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rob Herring <robh+dt@...nel.org>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Michael Walle <michael@...le.cc>, Uwe Kleine-König <u.kleine-koenig@...gutronix.de>, Jeremy Kerr <jk@...econstruct.com.au>, Raymond Hackley <raymondhackley@...tonmail.com>, netdev@...r.kernel.org, devicetree@...r.kernel.org
Subject: [PATCH v3 2/2] NFC: nxp-nci: Add pad supply voltage pvdd-supply

PN547/553, QN310/330 chips on some devices require a pad supply voltage
(PVDD). Otherwise, the NFC won't power up.

Implement support for pad supply voltage pvdd-supply that is enabled by
the nxp-nci driver so that the regulator gets enabled when needed.

Signed-off-by: Raymond Hackley <raymondhackley@...tonmail.com>
---
 drivers/nfc/nxp-nci/i2c.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
index d4c299be7949..6f01152d2c83 100644
--- a/drivers/nfc/nxp-nci/i2c.c
+++ b/drivers/nfc/nxp-nci/i2c.c
@@ -35,6 +35,7 @@ struct nxp_nci_i2c_phy {

 	struct gpio_desc *gpiod_en;
 	struct gpio_desc *gpiod_fw;
+	struct regulator *pvdd;

 	int hard_fault; /*
 			 * < 0 if hardware error occurred (e.g. i2c err)
@@ -263,6 +264,20 @@ static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
 	{ }
 };

+static void nxp_nci_i2c_poweroff(void *data)
+{
+	struct nxp_nci_i2c_phy *phy = data;
+	struct device *dev = &phy->i2c_dev->dev;
+	struct regulator *pvdd = phy->pvdd;
+	int r;
+
+	if (!IS_ERR(pvdd) && regulator_is_enabled(pvdd)) {
+		r = regulator_disable(pvdd);
+		if (r < 0)
+			dev_warn(dev, "Failed to disable regulator pvdd: %d\n", r);
+	}
+}
+
 static int nxp_nci_i2c_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -298,6 +313,25 @@ static int nxp_nci_i2c_probe(struct i2c_client *client)
 		return PTR_ERR(phy->gpiod_fw);
 	}

+	phy->pvdd = devm_regulator_get_optional(dev, "pvdd");
+	if (IS_ERR(phy->pvdd)) {
+		r = PTR_ERR(phy->pvdd);
+		if (r != -ENODEV)
+			return dev_err_probe(dev, r, "Failed to get regulator pvdd\n");
+	} else {
+		r = regulator_enable(phy->pvdd);
+		if (r < 0) {
+			nfc_err(dev, "Failed to enable regulator pvdd: %d\n", r);
+			return r;
+		}
+	}
+
+	r = devm_add_action_or_reset(dev, nxp_nci_i2c_poweroff, phy);
+	if (r < 0) {
+		nfc_err(dev, "Failed to install poweroff handler: %d\n", r);
+		return r;
+	}
+
 	r = nxp_nci_probe(phy, &client->dev, &i2c_phy_ops,
 			  NXP_NCI_I2C_MAX_PAYLOAD, &phy->ndev);
 	if (r < 0)
-- 
2.30.2