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| author | Sean Nyekjaer <sean@geanix.com> | 2019-12-11 14:58:51 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2020-01-02 15:34:26 +0100 |
| commit | c3083124e6a1c0d6cd4fe3b3f627b488bd3b10c4 (patch) | |
| tree | 9decf44ffa66e54978e82a88e9a3d6f2d673ca8b /drivers/net/can | |
| parent | 3814ca3a10be795693e9d95142c69134c6189a9b (diff) | |
| download | blackbird-op-linux-c3083124e6a1c0d6cd4fe3b3f627b488bd3b10c4.tar.gz blackbird-op-linux-c3083124e6a1c0d6cd4fe3b3f627b488bd3b10c4.zip | |
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>
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/m_can/tcan4x5x.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c index a69476f5aec6..ee22e39f131b 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", |
