can: tcan4x5x: tcan4x5x_parse_config(): reset device before register access
It's a good idea to reset a ip-block/spi device before using it, this
patch will reset the device.
And a generic reset function if needed elsewhere.
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
index a69476f..ee22e39 100644
--- a/drivers/net/can/m_can/tcan4x5x.c
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -166,6 +166,28 @@ static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
}
}
+static int tcan4x5x_reset(struct tcan4x5x_priv *priv)
+{
+ int ret = 0;
+
+ if (priv->reset_gpio) {
+ gpiod_set_value(priv->reset_gpio, 1);
+
+ /* tpulse_width minimum 30us */
+ usleep_range(30, 100);
+ gpiod_set_value(priv->reset_gpio, 0);
+ } else {
+ ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG,
+ TCAN4X5X_SW_RESET);
+ if (ret)
+ return ret;
+ }
+
+ usleep_range(700, 1000);
+
+ return ret;
+}
+
static int regmap_spi_gather_write(void *context, const void *reg,
size_t reg_len, const void *val,
size_t val_len)
@@ -351,6 +373,7 @@ static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
{
struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
+ int ret;
tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
GPIOD_OUT_HIGH);
@@ -366,7 +389,9 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
if (IS_ERR(tcan4x5x->reset_gpio))
tcan4x5x->reset_gpio = NULL;
- usleep_range(700, 1000);
+ ret = tcan4x5x_reset(tcan4x5x);
+ if (ret)
+ return ret;
tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
"device-state",