1 files changed, 38 insertions, 8 deletions

diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index f5dfc33b97c0..c3f4ff08ac38 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -49,6 +49,7 @@
 #include <linux/pm.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <dt-bindings/mux/mux.h>
@@ -116,6 +117,9 @@ struct pca954x {
 	unsigned int irq_mask;
 	raw_spinlock_t lock;
 	struct regulator *supply;
+
+	struct gpio_desc *reset_gpio;
+	struct reset_control *reset_cont;
 };
 
 /* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */
@@ -518,6 +522,35 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data)
 	return ret;
 }
 
+static int pca954x_get_reset(struct device *dev, struct pca954x *data)
+{
+	data->reset_cont = devm_reset_control_get_optional_shared(dev, NULL);
+	if (IS_ERR(data->reset_cont))
+		return dev_err_probe(dev, PTR_ERR(data->reset_cont),
+				     "Failed to get reset\n");
+	else if (data->reset_cont)
+		return 0;
+
+	/*
+	 * fallback to legacy reset-gpios
+	 */
+	data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(data->reset_gpio)) {
+		return dev_err_probe(dev, PTR_ERR(data->reset_gpio),
+				     "Failed to get reset gpio");
+	}
+
+	return 0;
+}
+
+static void pca954x_reset_deassert(struct pca954x *data)
+{
+	if (data->reset_cont)
+		reset_control_deassert(data->reset_cont);
+	else
+		gpiod_set_value_cansleep(data->reset_gpio, 0);
+}
+
 /*
  * I2C init/probing/exit functions
  */
@@ -526,7 +559,6 @@ static int pca954x_probe(struct i2c_client *client)
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
 	struct i2c_adapter *adap = client->adapter;
 	struct device *dev = &client->dev;
-	struct gpio_desc *gpio;
 	struct i2c_mux_core *muxc;
 	struct pca954x *data;
 	int num;
@@ -554,15 +586,13 @@ static int pca954x_probe(struct i2c_client *client)
 		return dev_err_probe(dev, ret,
 				     "Failed to enable vdd supply\n");
 
-	/* Reset the mux if a reset GPIO is specified. */
-	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
-	if (IS_ERR(gpio)) {
-		ret = PTR_ERR(gpio);
+	ret = pca954x_get_reset(dev, data);
+	if (ret)
 		goto fail_cleanup;
-	}
-	if (gpio) {
+
+	if (data->reset_cont || data->reset_gpio) {
 		udelay(1);
-		gpiod_set_value_cansleep(gpio, 0);
+		pca954x_reset_deassert(data);
 		/* Give the chip some time to recover. */
 		udelay(1);
 	}