[RFC 2/7] tty: add support for "tty slave" devices
From: Sebastian Reichel <sre@kernel.org>
Date: 2016-08-13 03:15:10
Also in:
linux-bluetooth, linux-omap, linux-serial, lkml
Subsystem:
open firmware and flattened device tree bindings, the rest, tty layer and serial drivers · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: NeilBrown <redacted> 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 <redacted> Signed-off-by: Sebastian Reichel <sre@kernel.org> --- 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