[RFC v2 11/13] usb: port: Parse pwrseq phandle from Device Tree

[Krzysztof Kozlowski]

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.kozlow...@samsung.com>
---
 drivers/usb/core/hub.h  |  3 +++
 drivers/usb/core/port.c | 15 +++++++++++++++
 2 files changed, 18 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 14718a9ffcfb..a875bd342452 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"
 
@@ -532,6 +534,14 @@ int usb_hub_create_port_device(struct usb_hub *hub, int 
port1)
                return retval;
        }
 
+       port_dev->dev.of_node = usb_of_get_child_node(hub->hdev->dev.of_node, 
port1);
+       port_dev->pwrseq = pwrseq_alloc(&port_dev->dev);
+       if (IS_ERR(port_dev->pwrseq)) {
+               device_unregister(&port_dev->dev);
+               /* TODO: what about EPROBE_DEFER? */
+               return PTR_ERR(port_dev->pwrseq);
+       }
+
        find_and_link_peer(hub, port1);
 
        /*
@@ -573,8 +583,13 @@ 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