6.12-stable review patch. If anyone has any objections, please let me know.
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From: Brett Werling brett.werling@garmin.com
[ Upstream commit 0f97a7588db7a545ea07ee0d512789bfad4931d8 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7062a2939f501..e8995738cf996 100644 --- a/drivers/net/can/m_can/tcan4x5x-core.c +++ b/drivers/net/can/m_can/tcan4x5x-core.c @@ -335,21 +335,19 @@ 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", @@ -361,14 +359,31 @@ 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; @@ -459,15 +474,21 @@ 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; }