Change since v5: Add usb_autopm_get/put_interface() around the port
power operations in the control attribute's callback to deal with
situation that control attribute is changed when the usb hub is suspended.
Change since v4: Add clear PORT_POWER if power policy is "off" in the
hub_power_on(). Return -EIO if set/clear PORT_POWER fails in the store_port_power_control()
This patch is to add two attributes for each usb hub ports to control port's power.
Control port's power through setting or clearing PORT_POWER feature.
control has two options. "auto", "on" and "off"
"on" - port power must be on.
"off" - port power must be off.
state reports usb port's power state
"on" - power on
"off" - power off
"error" - can't get power state
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-usb | 25 ++++++
drivers/usb/core/hub.c | 133 ++++++++++++++++++++++++++++++-
2 files changed, 157 insertions(+), 1 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb
index 6df4e6f..abe4ea4 100644
--- a/Documentation/ABI/testing/sysfs-bus-usb
+++ b/Documentation/ABI/testing/sysfs-bus-usb
@@ -208,3 +208,28 @@ Description:
such as ACPI. This file will read either "removable" or
"fixed" if the information is available, and "unknown"
otherwise.
+
+What: /sys/bus/usb/devices/.../(hub interface)/portX/control
+Date: June 2012
+Contact Lan Tianyu <tianyu.lan@xxxxxxxxx>
+Description:
+ The /sys/bus/usb/devices/.../(hub interface)/portX/control
+ attribute allows user space to control the power policy on
+ the usb port.
+
+ All ports have one of the following two values for control
+ "on" - port power must be on.
+ "off" - port power must be off.
+
+What: /sys/bus/usb/devices/.../(hub interface)/portX/state
+Date: June 2012
+Contact Lan Tianyu <tianyu.lan@xxxxxxxxx>
+Description:
+ The /sys/bus/usb/devices/.../(hub interface)/portX/state
+ attribute allows user space to check hub port's power state.
+
+ All ports have three following states
+ "on" - port power on
+ "off" - port power off
+ "error" - can't get the hub port's power state
+
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 25dfd71..0a5f7ff 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -37,11 +37,17 @@
#endif
#endif
+enum port_power_policy {
+ USB_PORT_POWER_ON = 0,
+ USB_PORT_POWER_OFF,
+};
+
struct usb_port {
struct usb_device *child;
struct device dev;
struct dev_state *port_owner;
enum usb_port_connect_type connect_type;
+ enum port_power_policy port_power_policy;
};
struct usb_hub {
@@ -95,6 +101,10 @@ struct device_type usb_port_device_type = {
.name = "usb_port",
};
+static const char on_string[] = "on";
+static const char off_string[] = "off";
+static const struct attribute_group *port_dev_group[];
+
static inline int hub_is_superspeed(struct usb_device *hdev)
{
return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS);
@@ -847,7 +857,12 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
dev_dbg(hub->intfdev, "trying to enable port power on "
"non-switchable hub\n");
for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
- set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
+ if (hub->ports[port1 - 1]->port_power_policy
+ == USB_PORT_POWER_ON)
+ set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
+ else
+ clear_port_feature(hub->hdev, port1,
+ USB_PORT_FEAT_POWER);
/* Wait at least 100 msec for power to become stable */
delay = max(pgood_delay, (unsigned) 100);
@@ -1260,6 +1275,7 @@ static int usb_hub_create_port_device(struct usb_hub *hub,
hub->ports[port1 - 1] = port_dev;
port_dev->dev.parent = hub->intfdev;
+ port_dev->dev.groups = port_dev_group;
port_dev->dev.type = &usb_port_device_type;
port_dev->dev.release = usb_port_device_release;
dev_set_name(&port_dev->dev, "port%d", port1);
@@ -2609,6 +2625,25 @@ static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
return ret;
}
+static int usb_get_hub_port_power_state(struct usb_device *hdev, int port1)
+{
+ struct usb_hub *hub = hdev_to_hub(hdev);
+ struct usb_port_status data;
+ u16 portstatus;
+ int ret;
+
+ ret = get_port_status(hub->hdev, port1, &data);
+ if (ret < 4) {
+ dev_err(hub->intfdev,
+ "%s failed (err = %d)\n", __func__, ret);
+ if (ret >= 0)
+ ret = -EIO;
+ return ret;
+ } else
+ portstatus = le16_to_cpu(data.wPortStatus);
+ return port_is_power_on(hub, portstatus);
+}
+
#ifdef CONFIG_PM
/* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
@@ -4550,6 +4585,102 @@ static int hub_thread(void *__unused)
return 0;
}
+static ssize_t show_port_power_state(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct usb_device *udev = to_usb_device(dev->parent->parent);
+ struct usb_interface *intf = to_usb_interface(dev->parent);
+ int port1, power_state;
+ const char *result;
+
+ sscanf(dev_name(dev), "port%d", &port1);
+ usb_autopm_get_interface(intf);
+ power_state = usb_get_hub_port_power_state(udev, port1);
+ usb_autopm_put_interface(intf);
+ if (power_state == 1)
+ result = on_string;
+ else if (!power_state)
+ result = off_string;
+ else
+ result = "error";
+ return sprintf(buf, "%s\n", result);
+}
+static DEVICE_ATTR(state, S_IRUGO, show_port_power_state, NULL);
+
+static ssize_t show_port_power_control(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct usb_port *hub_port = to_usb_port(dev);
+ const char *result;
+
+ switch (hub_port->port_power_policy) {
+ case USB_PORT_POWER_ON:
+ result = on_string;
+ break;
+ case USB_PORT_POWER_OFF:
+ result = off_string;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return sprintf(buf, "%s\n", result);
+}
+
+static ssize_t store_port_power_control(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct usb_device *hdev = to_usb_device(dev->parent->parent);
+ struct usb_interface *intf = to_usb_interface(dev->parent);
+ struct usb_port *hub_port = to_usb_port(dev);
+ int port1, ret, len = count;
+ char *cp;
+
+ sscanf(dev_name(dev), "port%d", &port1);
+ cp = memchr(buf, '\n', count);
+ if (cp)
+ len = cp - buf;
+ if (len == sizeof on_string - 1
+ && strncmp(buf, on_string, len) == 0) {
+ hub_port->port_power_policy = USB_PORT_POWER_ON;
+ usb_autopm_get_interface(intf);
+ ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
+ usb_autopm_put_interface(intf);
+ if (ret < 0)
+ return -EIO;
+ } else if (len == sizeof off_string - 1
+ && strncmp(buf, off_string, len) == 0) {
+ struct usb_hub *hub = hdev_to_hub(hdev);
+
+ hub_port->port_power_policy = USB_PORT_POWER_OFF;
+ usb_autopm_get_interface(intf);
+ hub_port_logical_disconnect(hub, port1);
+ ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
+ usb_autopm_put_interface(intf);
+ if (ret < 0)
+ return -EIO;
+ } else
+ return -EINVAL;
+
+ return count;
+}
+static DEVICE_ATTR(control, S_IWUSR | S_IRUGO, show_port_power_control,
+ store_port_power_control);
+
+static struct attribute *port_dev_attrs[] = {
+ &dev_attr_control.attr,
+ &dev_attr_state.attr,
+ NULL,
+};
+
+static struct attribute_group port_dev_attr_grp = {
+ .attrs = port_dev_attrs,
+};
+
+static const struct attribute_group *port_dev_group[] = {
+ &port_dev_attr_grp,
+ NULL,
+};
+
static const struct usb_device_id hub_id_table[] = {
{ .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
.bDeviceClass = USB_CLASS_HUB},
--
1.7.6.rc2.8.g28eb
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