i2c: mux: pca954x: force reset on probe if available (a2f8445d) · Commits · 戴 / test

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>

drivers/i2c/muxes/i2c-mux-pca954x.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -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)

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