linux-kernel - [PATCH 1/3] misc: eeprom: at24: add optional dovdd-supply

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Date: Fri, 26 Apr 2024 18:29:47 +0800
From: zoie.lin <zoie.lin@...iatek.com>
To: Bartosz Golaszewski <brgl@...ev.pl>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
	Arnd Bergmann <arnd@...db.de>, Greg Kroah-Hartman
	<gregkh@...uxfoundation.org>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown
	<broonie@...nel.org>, Matthias Brugger <matthias.bgg@...il.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
CC: <linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>,
	<linux-mediatek@...ts.infradead.org>,
	<Project_Global_Chrome_Upstream_Group@...iatek.com>, Zoie Lin
	<zoie.lin@...iatek.com>
Subject: [PATCH 1/3] misc: eeprom: at24: add optional dovdd-supply

From: Zoie Lin <zoie.lin@...iatek.com>

Incorporate support for the dovdd regulator, which supplies an
additional power source to the EEPROM.

Signed-off-by: Zoie Lin <zoie.lin@...iatek.com>
---
 drivers/misc/eeprom/at24.c | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 572333ead5fb..b96f6eda3ad2 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -86,6 +86,7 @@ struct at24_data {
 
 	struct nvmem_device *nvmem;
 	struct regulator *vcc_reg;
+	struct regulator *dovdd_reg;
 	void (*read_post)(unsigned int off, char *buf, size_t count);
 
 	/*
@@ -697,6 +698,14 @@ static int at24_probe(struct i2c_client *client)
 	if (IS_ERR(at24->vcc_reg))
 		return PTR_ERR(at24->vcc_reg);
 
+	at24->dovdd_reg = devm_regulator_get_optional(dev, "dovdd");
+	if (IS_ERR(at24->dovdd_reg)) {
+		if (PTR_ERR(at24->dovdd_reg) == -ENODEV)
+			at24->dovdd_reg = NULL;
+		else
+			return PTR_ERR(at24->dovdd_reg);
+	}
+
 	writable = !(flags & AT24_FLAG_READONLY);
 	if (writable) {
 		at24->write_max = min_t(unsigned int,
@@ -754,6 +763,14 @@ static int at24_probe(struct i2c_client *client)
 			return err;
 		}
 
+		if (at24->dovdd_reg != NULL) {
+			err = regulator_enable(at24->dovdd_reg);
+			if (err) {
+				dev_err(dev, "Failed to enable dovdd regulator\n");
+				return err;
+			}
+		}
+
 		pm_runtime_set_active(dev);
 	}
 	pm_runtime_enable(dev);
@@ -761,8 +778,11 @@ static int at24_probe(struct i2c_client *client)
 	at24->nvmem = devm_nvmem_register(dev, &nvmem_config);
 	if (IS_ERR(at24->nvmem)) {
 		pm_runtime_disable(dev);
-		if (!pm_runtime_status_suspended(dev))
+		if (!pm_runtime_status_suspended(dev)) {
 			regulator_disable(at24->vcc_reg);
+			if (at24->dovdd_reg != NULL)
+				regulator_disable(at24->dovdd_reg);
+		}
 		return dev_err_probe(dev, PTR_ERR(at24->nvmem),
 				     "failed to register nvmem\n");
 	}
@@ -804,8 +824,11 @@ static void at24_remove(struct i2c_client *client)
 
 	pm_runtime_disable(&client->dev);
 	if (acpi_dev_state_d0(&client->dev)) {
-		if (!pm_runtime_status_suspended(&client->dev))
+		if (!pm_runtime_status_suspended(&client->dev)) {
 			regulator_disable(at24->vcc_reg);
+			if (at24->dovdd_reg != NULL)
+				regulator_disable(at24->dovdd_reg);
+		}
 		pm_runtime_set_suspended(&client->dev);
 	}
 }
@@ -815,14 +838,24 @@ static int __maybe_unused at24_suspend(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct at24_data *at24 = i2c_get_clientdata(client);
 
+	if (at24->dovdd_reg != NULL)
+		regulator_disable(at24->dovdd_reg);
+
 	return regulator_disable(at24->vcc_reg);
 }
 
 static int __maybe_unused at24_resume(struct device *dev)
 {
+	int err;
 	struct i2c_client *client = to_i2c_client(dev);
 	struct at24_data *at24 = i2c_get_clientdata(client);
 
+	if (at24->dovdd_reg != NULL) {
+		err = regulator_enable(at24->dovdd_reg);
+		if (err)
+			return err;
+	}
+
 	return regulator_enable(at24->vcc_reg);
 }
 
-- 
2.18.0