nWKRQ supports an output voltage of either the internal reference voltage
(3.6V) or the reference voltage of the digital interface 0 - 6V.
Add the devicetree option ti,nwkrq-voltage-sel to be able to select
between them.
Default is kept as the internal reference voltage.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
---
 drivers/net/can/m_can/tcan4x5x-core.c | 35 +++++++++++++++++++++++++++++++++++
 drivers/net/can/m_can/tcan4x5x.h      |  2 ++
 2 files changed, 37 insertions(+)

diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index 2f73bf3abad889c222f15c39a3d43de1a1cf5fbb..264bba830be50033347056da994102f8b614e51b 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -92,6 +92,8 @@
 #define TCAN4X5X_MODE_STANDBY BIT(6)
 #define TCAN4X5X_MODE_NORMAL BIT(7)
 
+#define TCAN4X5X_NWKRQ_VOLTAGE_MASK BIT(19)
+
 #define TCAN4X5X_DISABLE_WAKE_MSK	(BIT(31) | BIT(30))
 #define TCAN4X5X_DISABLE_INH_MSK	BIT(9)
 
@@ -267,6 +269,11 @@ static int tcan4x5x_init(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
+	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				 TCAN4X5X_NWKRQ_VOLTAGE_MASK, tcan4x5x->nwkrq_voltage);
+	if (ret)
+		return ret;
+
 	return ret;
 }
 
@@ -318,6 +325,28 @@ static const struct tcan4x5x_version_info
 	return &tcan4x5x_versions[TCAN4X5X];
 }
 
+static int tcan4x5x_get_dt_data(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
+	struct device_node *np = cdev->dev->of_node;
+	u8 prop;
+	int ret;
+
+	ret = of_property_read_u8(np, "ti,nwkrq-voltage-sel", &prop);
+	if (!ret) {
+		if (prop <= 1)
+			tcan4x5x->nwkrq_voltage = prop;
+		else
+			dev_warn(cdev->dev,
+				 "nwkrq-voltage-sel have invalid option: %u\n",
+				 prop);
+	} else {
+		tcan4x5x->nwkrq_voltage = 0;
+	}
+
+	return 0;
+}
+
 static int tcan4x5x_get_gpios(struct m_can_classdev *cdev,
 			      const struct tcan4x5x_version_info *version_info)
 {
@@ -453,6 +482,12 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 		goto out_power;
 	}
 
+	ret = tcan4x5x_get_dt_data(mcan_class);
+	if (ret) {
+		dev_err(&spi->dev, "Getting dt data failed %pe\n", ERR_PTR(ret));
+		goto out_power;
+	}
+
 	tcan4x5x_check_wake(priv);
 
 	ret = tcan4x5x_write_tcan_reg(mcan_class, TCAN4X5X_INT_EN, 0);
diff --git a/drivers/net/can/m_can/tcan4x5x.h b/drivers/net/can/m_can/tcan4x5x.h
index e62c030d3e1e5a713c997e7c8ecad4a44aff4e6a..04ebe5c64f4f7056a62e72e717cb85dd3817ab9c 100644
--- a/drivers/net/can/m_can/tcan4x5x.h
+++ b/drivers/net/can/m_can/tcan4x5x.h
@@ -42,6 +42,8 @@ struct tcan4x5x_priv {
 
 	struct tcan4x5x_map_buf map_buf_rx;
 	struct tcan4x5x_map_buf map_buf_tx;
+
+	u8 nwkrq_voltage;
 };
 
 static inline void

-- 
2.46.2