Add support for "i2c-mux-idle-disconnect" binding to match the behavior, already present in upstream kernel driver. This feature is a must have for I2C bus topologies with multiple muxes connected to child segments containing slaves with identical addresses (e.g. ZII's SCU4)
Signed-off-by: Andrey Smirnov <[email protected]> --- drivers/i2c/muxes/i2c-mux-pca954x.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 42bde5ed1c..aa7dcb8c31 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -170,6 +170,16 @@ static int pca954x_select_chan(struct i2c_adapter *adap, return ret; } +static int pca954x_deselect_chan(struct i2c_adapter *adap, + void *client, u32 chan) +{ + struct pca954x *data = i2c_get_clientdata(client); + + /* Deselect active channel */ + data->last_chan = 0; + return pca954x_reg_write(adap, client, data->last_chan); +} + /* * I2C init/probing/exit functions */ @@ -182,6 +192,7 @@ static int pca954x_probe(struct device_d *dev) uintptr_t tmp; int ret = -ENODEV; int gpio; + bool idle_disconnect; data = kzalloc(sizeof(struct pca954x), GFP_KERNEL); if (!data) { @@ -209,6 +220,9 @@ static int pca954x_probe(struct device_d *dev) if (ret) goto exit_free; + idle_disconnect = of_property_read_bool(dev->device_node, + "i2c-mux-idle-disconnect"); + data->last_chan = 0; /* force the first selection */ /* Now create an adapter for each channel */ @@ -216,7 +230,10 @@ static int pca954x_probe(struct device_d *dev) data->virt_adaps[num] = i2c_add_mux_adapter(adap, &client->dev, client, - 0, num, pca954x_select_chan, NULL); + 0, num, pca954x_select_chan, + idle_disconnect ? + pca954x_deselect_chan : + NULL); if (data->virt_adaps[num] == NULL) { ret = -ENODEV; -- 2.21.0 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
