diff options
| author | Mike Looijmans <mike.looijmans@topic.nl> | 2018-05-01 13:42:12 +0200 |
|---|---|---|
| committer | Peter Rosin <peda@axentia.se> | 2018-05-19 23:54:47 +0200 |
| commit | a2f8445d4ca2796283c07d4ba8e78718071de863 (patch) | |
| tree | d42da01f4a618f564449d88bc933c70c0bf88cc6 /drivers | |
| parent | fca700d6d2190292f34282d50b613a9efb100f70 (diff) | |
| download | op-kernel-dev-a2f8445d4ca2796283c07d4ba8e78718071de863.zip op-kernel-dev-a2f8445d4ca2796283c07d4ba8e78718071de863.tar.gz | |
i2c: mux: pca954x: force reset on probe if available
Instead of just hogging the reset GPIO into deactivated state, activate and
then de-activate the reset. This allows for better recovery if the CPU was
reset halfway through an I2C transaction for example.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Peter Rosin <peda@axentia.se>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-pca954x.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 09bafd3..fe20b8e 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -36,6 +36,7 @@ */ #include <linux/device.h> +#include <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> @@ -389,10 +390,16 @@ static int pca954x_probe(struct i2c_client *client, i2c_set_clientdata(client, muxc); data->client = client; - /* Get the mux out of reset if a reset GPIO is specified. */ - gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW); + /* Reset the mux if a reset GPIO is specified. */ + gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(gpio)) return PTR_ERR(gpio); + if (gpio) { + udelay(1); + gpiod_set_value_cansleep(gpio, 0); + /* Give the chip some time to recover. */ + udelay(1); + } match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev); if (match) |
