[PATCH 2/2] net: m_can: Make wake-up gpio an optional

From: Dan Murphy
Date: Wed Dec 04 2019 - 12:53:30 EST


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@xxxxxx>
CC: Sean Nyekjaer <sean@xxxxxxxxxx>
---
drivers/net/can/m_can/tcan4x5x.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
index 3db619209fe1..6e37c3fd87af 100644
--- a/drivers/net/can/m_can/tcan4x5x.c
+++ b/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 +340,15 @@ 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 +356,10 @@ 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",
@@ -428,10 +441,6 @@ 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);
@@ -441,6 +450,10 @@ 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);
--
2.23.0