[PATCH v2] NFC: trf7970a: disable all regulators on removal

[PATCH v2] NFC: trf7970a: disable all regulators on removal

[Paul Geurts]

During module probe, regulator 'vin' and 'vdd-io' are used and enabled,
but the vdd-io regulator overwrites the 'vin' regulator pointer. During
remove, only the vdd-io is disabled, as the vin regulator pointer is not
available anymore. When regulator_put() is called during resource
cleanup a kernel warning is given, as the regulator is still enabled.

Store the two regulators in separate pointers and disable both the
regulators on module remove.

Fixes: 49d22c70aaf0 ("NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage")
Signed-off-by: Paul Geurts <paul_geurts@live.nl>
---
V1 -> V2: Removed blank line between Fixes and Signed-off-by tag

 drivers/nfc/trf7970a.c | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 7eb17f46a815..9e1a34e23af2 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -424,7 +424,8 @@ struct trf7970a {
 	enum trf7970a_state		state;
 	struct device			*dev;
 	struct spi_device		*spi;
-	struct regulator		*regulator;
+	struct regulator		*vin_regulator;
+	struct regulator		*vddio_regulator;
 	struct nfc_digital_dev		*ddev;
 	u32				quirks;
 	bool				is_initiator;
@@ -1883,7 +1884,7 @@ static int trf7970a_power_up(struct trf7970a *trf)
 	if (trf->state != TRF7970A_ST_PWR_OFF)
 		return 0;
 
-	ret = regulator_enable(trf->regulator);
+	ret = regulator_enable(trf->vin_regulator);
 	if (ret) {
 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
 		return ret;
@@ -1926,7 +1927,7 @@ static int trf7970a_power_down(struct trf7970a *trf)
 	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
 		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
 
-	ret = regulator_disable(trf->regulator);
+	ret = regulator_disable(trf->vin_regulator);
 	if (ret)
 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
 			ret);
@@ -2065,37 +2066,37 @@ static int trf7970a_probe(struct spi_device *spi)
 	mutex_init(&trf->lock);
 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
 
-	trf->regulator = devm_regulator_get(&spi->dev, "vin");
-	if (IS_ERR(trf->regulator)) {
-		ret = PTR_ERR(trf->regulator);
+	trf->vin_regulator = devm_regulator_get(&spi->dev, "vin");
+	if (IS_ERR(trf->vin_regulator)) {
+		ret = PTR_ERR(trf->vin_regulator);
 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
 		goto err_destroy_lock;
 	}
 
-	ret = regulator_enable(trf->regulator);
+	ret = regulator_enable(trf->vin_regulator);
 	if (ret) {
 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
 		goto err_destroy_lock;
 	}
 
-	uvolts = regulator_get_voltage(trf->regulator);
+	uvolts = regulator_get_voltage(trf->vin_regulator);
 	if (uvolts > 4000000)
 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
 
-	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
-	if (IS_ERR(trf->regulator)) {
-		ret = PTR_ERR(trf->regulator);
+	trf->vddio_regulator = devm_regulator_get(&spi->dev, "vdd-io");
+	if (IS_ERR(trf->vddio_regulator)) {
+		ret = PTR_ERR(trf->vddio_regulator);
 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
-		goto err_destroy_lock;
+		goto err_disable_vin_regulator;
 	}
 
-	ret = regulator_enable(trf->regulator);
+	ret = regulator_enable(trf->vddio_regulator);
 	if (ret) {
 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
-		goto err_destroy_lock;
+		goto err_disable_vin_regulator;
 	}
 
-	if (regulator_get_voltage(trf->regulator) == 1800000) {
+	if (regulator_get_voltage(trf->vddio_regulator) == 1800000) {
 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
 	}
@@ -2108,7 +2109,7 @@ static int trf7970a_probe(struct spi_device *spi)
 	if (!trf->ddev) {
 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
 		ret = -ENOMEM;
-		goto err_disable_regulator;
+		goto err_disable_vddio_regulator;
 	}
 
 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
@@ -2137,8 +2138,10 @@ static int trf7970a_probe(struct spi_device *spi)
 	trf7970a_shutdown(trf);
 err_free_ddev:
 	nfc_digital_free_device(trf->ddev);
-err_disable_regulator:
-	regulator_disable(trf->regulator);
+err_disable_vddio_regulator:
+	regulator_disable(trf->vddio_regulator);
+err_disable_vin_regulator:
+	regulator_disable(trf->vin_regulator);
 err_destroy_lock:
 	mutex_destroy(&trf->lock);
 	return ret;
@@ -2157,7 +2160,8 @@ static void trf7970a_remove(struct spi_device *spi)
 	nfc_digital_unregister_device(trf->ddev);
 	nfc_digital_free_device(trf->ddev);
 
-	regulator_disable(trf->regulator);
+	regulator_disable(trf->vddio_regulator);
+	regulator_disable(trf->vin_regulator);
 
 	mutex_destroy(&trf->lock);
 }
-- 
2.39.2

Re: [PATCH v2] NFC: trf7970a: disable all regulators on removal

[Krzysztof Kozlowski]

On 18/04/2024 21:25, Paul Geurts wrote:
> During module probe, regulator 'vin' and 'vdd-io' are used and enabled,
> but the vdd-io regulator overwrites the 'vin' regulator pointer. During
> remove, only the vdd-io is disabled, as the vin regulator pointer is not
> available anymore. When regulator_put() is called during resource
> cleanup a kernel warning is given, as the regulator is still enabled.
> 
> Store the two regulators in separate pointers and disable both the
> regulators on module remove.
> 
> Fixes: 49d22c70aaf0 ("NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage")
> Signed-off-by: Paul Geurts <paul_geurts@live.nl>

This is a friendly reminder during the review process.

It looks like you received a tag and forgot to add it.

If you do not know the process, here is a short explanation:
Please add Acked-by/Reviewed-by/Tested-by tags when posting new
versions, under or above your Signed-off-by tag. Tag is "received", when
provided in a message replied to you on the mailing list. Tools like b4
can help here. However, there's no need to repost patches *only* to add
the tags. The upstream maintainer will do that for tags received on the
version they apply.

https://elixir.bootlin.com/linux/v6.5-rc3/source/Documentation/process/submitting-patches.rst#L577

If a tag was not added on purpose, please state why and what changed.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v2] NFC: trf7970a: disable all regulators on removal

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 18 Apr 2024 21:25:38 +0200 you wrote:
> During module probe, regulator 'vin' and 'vdd-io' are used and enabled,
> but the vdd-io regulator overwrites the 'vin' regulator pointer. During
> remove, only the vdd-io is disabled, as the vin regulator pointer is not
> available anymore. When regulator_put() is called during resource
> cleanup a kernel warning is given, as the regulator is still enabled.
> 
> Store the two regulators in separate pointers and disable both the
> regulators on module remove.
> 
> [...]

Here is the summary with links:
  - [v2] NFC: trf7970a: disable all regulators on removal
    https://git.kernel.org/netdev/net/c/6bea4f03c6a4

You are awesome, thank you!
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