can: tcan45x: Make wake-up GPIO an optional GPIO

The device has the ability to disable the wake-up pin option. The
wake-up pin can be either force to GND or Vsup and does not have to be
tied to a GPIO. In order for the device to not use the wake-up feature
write the register to disable the WAKE_CONFIG option.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Cc: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/m_can/tcan4x5x.c

@@ -101,6 +101,8 @@
 #define TCAN4X5X_MODE_STANDBY BIT(6)
 #define TCAN4X5X_MODE_NORMAL BIT(7)
 
+#define TCAN4X5X_DISABLE_WAKE_MSK	(BIT(31) | BIT(30))
+
 #define TCAN4X5X_SW_RESET BIT(2)
 
 #define TCAN4X5X_MCAN_CONFIGURED BIT(5)
@@ -338,6 +340,14 @@ static int tcan4x5x_init(struct m_can_classdev *cdev)
 	return ret;
 }
 
+static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
+
+	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				  TCAN4X5X_DISABLE_WAKE_MSK, 0x00);
+}
+
 static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
 {
 	struct tcan4x5x_priv *tcan4x5x = cdev->device_data;
@@ -345,8 +355,10 @@ static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
 	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
 						    GPIOD_OUT_HIGH);
 	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
-		dev_err(cdev->dev, "device-wake gpio not defined\n");
-		return -EINVAL;
+		if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		tcan4x5x_disable_wake(cdev);
 	}
 
 	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
@@ -430,10 +442,6 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 
 	spi_set_drvdata(spi, priv);
 
-	ret = tcan4x5x_parse_config(mcan_class);
-	if (ret)
-		goto out_clk;
-
 	/* Configure the SPI bus */
 	spi->bits_per_word = 32;
 	ret = spi_setup(spi);
@@ -443,6 +451,10 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
 					&spi->dev, &tcan4x5x_regmap);
 
+	ret = tcan4x5x_parse_config(mcan_class);
+	if (ret)
+		goto out_clk;
+
 	tcan4x5x_power_enable(priv->power, 1);
 
 	ret = m_can_class_register(mcan_class);