usb/core: consider link speed while looking at bMaxPower
The USB 2.0 specification says that bMaxPower is the maximum power
consumption expressed in 2 mA units and the USB 3.0 specification says
that it is expressed in 8 mA units.
This patch adds a helper function usb_get_max_power() which computes the
value based on config & usb_device's speed value. The the device descriptor
dump computes the value on its own.
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 818e4a0..3f81a3d 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -17,7 +17,7 @@
#include "usb.h"
/* Active configuration fields */
-#define usb_actconfig_show(field, multiplier, format_string) \
+#define usb_actconfig_show(field, format_string) \
static ssize_t show_##field(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
@@ -28,18 +28,31 @@
actconfig = udev->actconfig; \
if (actconfig) \
return sprintf(buf, format_string, \
- actconfig->desc.field * multiplier); \
+ actconfig->desc.field); \
else \
return 0; \
} \
-#define usb_actconfig_attr(field, multiplier, format_string) \
-usb_actconfig_show(field, multiplier, format_string) \
-static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
+#define usb_actconfig_attr(field, format_string) \
+ usb_actconfig_show(field, format_string) \
+ static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
-usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
-usb_actconfig_attr(bmAttributes, 1, "%2x\n")
-usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
+usb_actconfig_attr(bNumInterfaces, "%2d\n")
+usb_actconfig_attr(bmAttributes, "%2x\n")
+
+static ssize_t show_bMaxPower(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct usb_device *udev;
+ struct usb_host_config *actconfig;
+
+ udev = to_usb_device(dev);
+ actconfig = udev->actconfig;
+ if (!actconfig)
+ return 0;
+ return sprintf(buf, "%dmA\n", usb_get_max_power(udev, actconfig));
+}
+static DEVICE_ATTR(bMaxPower, S_IRUGO, show_bMaxPower, NULL);
static ssize_t show_configuration_string(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -56,7 +69,7 @@
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
/* configuration value is always present, and r/w */
-usb_actconfig_show(bConfigurationValue, 1, "%u\n");
+usb_actconfig_show(bConfigurationValue, "%u\n");
static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,