[PATCH net 0/1] pull-request: can 2025-07-15

[PATCH net 0/1] pull-request: can 2025-07-15

[Marc Kleine-Budde]

Hello netdev-team,

this is a pull request of 1 patch for net/main.

Brett Werling's patch for the tcan4x5x glue code driver fixes the
detection of chips which are held in reset/sleep and must be woken up
by GPIO prior to communication.

regards,
Marc

---

The following changes since commit f0f2b992d8185a0366be951685e08643aae17d6d:

  net: phy: Don't register LEDs for genphy (2025-07-14 17:53:09 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git tags/linux-can-fixes-for-6.16-20250715

for you to fetch changes up to 0f97a7588db7a545ea07ee0d512789bfad4931d8:

  can: tcan4x5x: fix reset gpio usage during probe (2025-07-15 11:59:43 +0200)

----------------------------------------------------------------
linux-can-fixes-for-6.16-20250715

----------------------------------------------------------------
Brett Werling (1):
      can: tcan4x5x: fix reset gpio usage during probe

 drivers/net/can/m_can/tcan4x5x-core.c | 61 +++++++++++++++++++++++------------
 1 file changed, 41 insertions(+), 20 deletions(-)

[PATCH net] can: tcan4x5x: fix reset gpio usage during probe

[Marc Kleine-Budde]

From: Brett Werling <brett.werling@garmin.com>

Fixes reset GPIO usage during probe by ensuring we retrieve the GPIO and
take the device out of reset (if it defaults to being in reset) before
we attempt to communicate with the device. This is achieved by moving
the call to tcan4x5x_get_gpios() before tcan4x5x_find_version() and
avoiding any device communication while getting the GPIOs. Once we
determine the version, we can then take the knowledge of which GPIOs we
obtained and use it to decide whether we need to disable the wake or
state pin functions within the device.

This change is necessary in a situation where the reset GPIO is pulled
high externally before the CPU takes control of it, meaning we need to
explicitly bring the device out of reset before we can start
communicating with it at all.

This also has the effect of fixing an issue where a reset of the device
would occur after having called tcan4x5x_disable_wake(), making the
original behavior not actually disable the wake. This patch should now
disable wake or state pin functions well after the reset occurs.

Signed-off-by: Brett Werling <brett.werling@garmin.com>
Link: https://patch.msgid.link/20250711141728.1826073-1-brett.werling@garmin.com
Cc: Markus Schneider-Pargmann <msp@baylibre.com>
Fixes: 142c6dc6d9d7 ("can: tcan4x5x: Add support for tcan4552/4553")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/m_can/tcan4x5x-core.c | 61 ++++++++++++++++++---------
 1 file changed, 41 insertions(+), 20 deletions(-)

diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index 8edaa339d590..39b0b5277b11 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -343,21 +343,19 @@ static void tcan4x5x_get_dt_data(struct m_can_classdev *cdev)
 		of_property_read_bool(cdev->dev->of_node, "ti,nwkrq-voltage-vio");
 }
 
-static int tcan4x5x_get_gpios(struct m_can_classdev *cdev,
-			      const struct tcan4x5x_version_info *version_info)
+static int tcan4x5x_get_gpios(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 	int ret;
 
-	if (version_info->has_wake_pin) {
-		tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
-							    GPIOD_OUT_HIGH);
-		if (IS_ERR(tcan4x5x->device_wake_gpio)) {
-			if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
-				return -EPROBE_DEFER;
+	tcan4x5x->device_wake_gpio = devm_gpiod_get_optional(cdev->dev,
+							     "device-wake",
+							     GPIOD_OUT_HIGH);
+	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
+		if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
 
-			tcan4x5x_disable_wake(cdev);
-		}
+		tcan4x5x->device_wake_gpio = NULL;
 	}
 
 	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
@@ -369,14 +367,31 @@ static int tcan4x5x_get_gpios(struct m_can_classdev *cdev,
 	if (ret)
 		return ret;
 
-	if (version_info->has_state_pin) {
-		tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
-								      "device-state",
-								      GPIOD_IN);
-		if (IS_ERR(tcan4x5x->device_state_gpio)) {
-			tcan4x5x->device_state_gpio = NULL;
-			tcan4x5x_disable_state(cdev);
-		}
+	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
+							      "device-state",
+							      GPIOD_IN);
+	if (IS_ERR(tcan4x5x->device_state_gpio))
+		tcan4x5x->device_state_gpio = NULL;
+
+	return 0;
+}
+
+static int tcan4x5x_check_gpios(struct m_can_classdev *cdev,
+				const struct tcan4x5x_version_info *version_info)
+{
+	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
+	int ret;
+
+	if (version_info->has_wake_pin && !tcan4x5x->device_wake_gpio) {
+		ret = tcan4x5x_disable_wake(cdev);
+		if (ret)
+			return ret;
+	}
+
+	if (version_info->has_state_pin && !tcan4x5x->device_state_gpio) {
+		ret = tcan4x5x_disable_state(cdev);
+		if (ret)
+			return ret;
 	}
 
 	return 0;
@@ -468,15 +483,21 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 		goto out_m_can_class_free_dev;
 	}
 
+	ret = tcan4x5x_get_gpios(mcan_class);
+	if (ret) {
+		dev_err(&spi->dev, "Getting gpios failed %pe\n", ERR_PTR(ret));
+		goto out_power;
+	}
+
 	version_info = tcan4x5x_find_version(priv);
 	if (IS_ERR(version_info)) {
 		ret = PTR_ERR(version_info);
 		goto out_power;
 	}
 
-	ret = tcan4x5x_get_gpios(mcan_class, version_info);
+	ret = tcan4x5x_check_gpios(mcan_class, version_info);
 	if (ret) {
-		dev_err(&spi->dev, "Getting gpios failed %pe\n", ERR_PTR(ret));
+		dev_err(&spi->dev, "Checking gpios failed %pe\n", ERR_PTR(ret));
 		goto out_power;
 	}
 

base-commit: f0f2b992d8185a0366be951685e08643aae17d6d
-- 
2.47.2

Re: [PATCH net] can: tcan4x5x: fix reset gpio usage during probe

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Marc Kleine-Budde <mkl@pengutronix.de>:

On Tue, 15 Jul 2025 12:13:39 +0200 you wrote:
> From: Brett Werling <brett.werling@garmin.com>
> 
> Fixes reset GPIO usage during probe by ensuring we retrieve the GPIO and
> take the device out of reset (if it defaults to being in reset) before
> we attempt to communicate with the device. This is achieved by moving
> the call to tcan4x5x_get_gpios() before tcan4x5x_find_version() and
> avoiding any device communication while getting the GPIOs. Once we
> determine the version, we can then take the knowledge of which GPIOs we
> obtained and use it to decide whether we need to disable the wake or
> state pin functions within the device.
> 
> [...]

Here is the summary with links:
  - [net] can: tcan4x5x: fix reset gpio usage during probe
    https://git.kernel.org/netdev/net/c/0f97a7588db7

You are awesome, thank you!
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