From: NeilBrown <neilb@xxxxxxx> A "tty slave" is a device connected via UART. It may need a driver to, for example, power the device on when the tty is opened, and power it off when the tty is released. Signed-off-by: NeilBrown <neilb@xxxxxxx> Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx> --- Documentation/devicetree/bindings/serial/8250.txt | 4 ++++ drivers/tty/tty_io.c | 6 ++++++ 2 files changed, 10 insertions(+) diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt index f5561ac7e17e..ecb74730f71b 100644 --- a/Documentation/devicetree/bindings/serial/8250.txt +++ b/Documentation/devicetree/bindings/serial/8250.txt @@ -46,6 +46,10 @@ Optional properties: line respectively. It will use specified GPIO instead of the peripheral function pin for the UART feature. If unsure, don't specify this property. +Optional child node: +- a device connected to the uart can be specified as child node with + compatible value. + Note: * fsl,ns16550: ------------ diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 734a635e7363..39ff5dcdfd50 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -95,6 +95,7 @@ #include <linux/seq_file.h> #include <linux/serial.h> #include <linux/ratelimit.h> +#include <linux/of_platform.h> #include <linux/uaccess.h> @@ -3317,6 +3318,11 @@ struct device *tty_register_device_attr(struct tty_driver *driver, retval = device_register(dev); if (retval) goto error; + if (device && device->of_node) + /* Children are platform devices and will be + * runtime_pm managed by this tty. + */ + of_platform_populate(device->of_node, NULL, NULL, dev); return dev; -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
