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-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt3
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c11
2 files changed, 13 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
index 34a3fb6f8488..cf53d5fba20a 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
@@ -16,6 +16,9 @@ Required Properties:
Optional Properties:
- reset-gpios: Reference to the GPIO connected to the reset input.
+ - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all
+ children in idle state. This is necessary for example, if there are several
+ multiplexers on the bus and the devices behind them use same I2C addresses.
Example:
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index ec11b404b433..3d8f4fe2e47e 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -41,6 +41,7 @@
#include <linux/i2c-mux.h>
#include <linux/i2c/pca954x.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/pm.h>
#include <linux/slab.h>
@@ -186,6 +187,8 @@ static int pca954x_probe(struct i2c_client *client,
{
struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct device_node *of_node = client->dev.of_node;
+ bool idle_disconnect_dt;
struct gpio_desc *gpio;
int num, force, class;
struct pca954x *data;
@@ -217,8 +220,13 @@ static int pca954x_probe(struct i2c_client *client,
data->type = id->driver_data;
data->last_chan = 0; /* force the first selection */
+ idle_disconnect_dt = of_node &&
+ of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
+
/* Now create an adapter for each channel */
for (num = 0; num < chips[data->type].nchans; num++) {
+ bool idle_disconnect_pd = false;
+
force = 0; /* dynamic adap number */
class = 0; /* no class by default */
if (pdata) {
@@ -229,12 +237,13 @@ static int pca954x_probe(struct i2c_client *client,
} else
/* discard unconfigured channels */
break;
+ idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
}
data->virt_adaps[num] =
i2c_add_mux_adapter(adap, &client->dev, client,
force, num, class, pca954x_select_chan,
- (pdata && pdata->modes[num].deselect_on_exit)
+ (idle_disconnect_pd || idle_disconnect_dt)
? pca954x_deselect_mux : NULL);
if (data->virt_adaps[num] == NULL) {