[RFC v4 11/14] EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree

Krzysztof Kozlowski
2016-06-09T09:44:28Z

Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq
device. The pwrseq device will be used by USB hub to cycle the power
before activating ports.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
drivers/usb/core/hub.h | 3 +++
drivers/usb/core/port.c | 16 ++++++++++++++++
2 files changed, 19 insertions(+)

diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 34c1a7e22aae..68ca89780d26 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -24,6 +24,8 @@
#include <linux/usb/hcd.h>
#include "usb.h"

+struct pwrseq;
+
struct usb_hub {
struct device *intfdev; /* the "interface" device */
struct usb_device *hdev;
@@ -101,6 +103,7 @@ struct usb_port {
struct usb_dev_state *port_owner;
struct usb_port *peer;
struct dev_pm_qos_request *req;
+ struct pwrseq *pwrseq;
enum usb_port_connect_type connect_type;
usb_port_location_t location;
struct mutex status_lock;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 460c855be0d0..4fce0250179c 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -18,6 +18,8 @@

#include <linux/slab.h>
#include <linux/pm_qos.h>
+#include <linux/pwrseq.h>
+#include <linux/usb/of.h>

#include "hub.h"

@@ -526,6 +528,15 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
return retval;
}

+ port_dev->dev.of_node = usb_of_get_child_node(hdev->dev.parent->of_node,
+ port1);
+ port_dev->pwrseq = pwrseq_alloc(&port_dev->dev, "usb-pwrseq");
+ if (IS_ERR(port_dev->pwrseq)) {
+ retval = PTR_ERR(port_dev->pwrseq);
+ device_unregister(&port_dev->dev);
+ return retval;
+ }
+
find_and_link_peer(hub, port1);

/*
@@ -567,8 +578,13 @@ void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
struct usb_port *port_dev = hub->ports[port1 - 1];
struct usb_port *peer;

+ pwrseq_power_off(port_dev->pwrseq);
+
peer = port_dev->peer;
if (peer)
unlink_peers(port_dev, peer);
+
+ pwrseq_free(port_dev->pwrseq);
+ port_dev->pwrseq = NULL;
device_unregister(&port_dev->dev);
}
--
1.9.1