Commit c3083124 authored by Sean Nyekjaer's avatar Sean Nyekjaer Committed by Marc Kleine-Budde
Browse files

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: default avatarSean Nyekjaer <sean@geanix.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 3814ca3a

drivers/net/can/m_can/tcan4x5x.c

+26 −1
Original line number Diff line number Diff line
@@ -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",

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