Oliver Neukum wrote:
> Am Dienstag, 26. Juni 2007 schrieb Jüri Reitel:
>
>> Hello.
>> How to correctly turn off the port power of usb hub (assuming hub
>> supports individual port power switching). Correctly means that all
>> drivers using the device on that port are notified before the power is
>> removed. Removed device could also be a usb hub.
>>
>
> You'd have to use the code paths usbfs uses for disconnecting via+ioctl.
>
Thank you for fast replay
Looked into drivers/usb/core/devio.c functions
usbdev_ioctl
proc_ioctl_default
proc_ioctl
USBDEVFS_DISCONNECT branch calls usb_driver_release_interface
As i can understand i should obtain list of all interfaces registered to
the port that i want to turn of the power and then call usbdev ioctl
drivers/usb/core/hub.c has function void usb_disconnect(struct
usb_device **pdev)
I exported usb_disconnect function and use it in my own driver where i
get struct usb_device * hub, because i know bus topology
static int set_usb_port_power_state(struct usb_device *hub, int port,
int new_state)
{
int ret;
if (new_state) {
ret = set_usb_hub_port_feature(hub, port, USB_PORT_FEAT_POWER);
} else {
//notify also children device drivers
if (port > 0 && port <= USB_MAXCHILDREN && hub->children[port -
1]) {
usb_disconnect(&hub->children[port - 1]);
}
ret = clear_usb_hub_port_feature(hub, port, USB_PORT_FEAT_POWER);
}
return ret;
}
hub is obtained with usb_get_dev and later put with usb_put_dev
First tests have been successful, with usb to usb hub and with root hub
althoug i had to change some files in usb/host/
The most hardest part to me is to understand the needed locks before
calling kernel functions
Following patch is only tested with NEC uPD720101 usb 2.0 Host
controller, this patch allows port power switching on nec root hub
diff -ruN linux-2.6.18/drivers/usb/host/ehci-hub.c
linux-2.6.18-modified/drivers/usb/host/ehci-hub.c
--- linux-2.6.18/drivers/usb/host/ehci-hub.c 2006-09-20
06:42:06.000000000 +0300
+++ linux-2.6.18-modified/drivers/usb/host/ehci-hub.c 2006-11-30
13:12:01.000000000 +0200
@@ -344,7 +344,7 @@
goto error;
wIndex--;
temp = readl (&ehci->regs->port_status [wIndex]);
- if (temp & PORT_OWNER)
+ if ((temp & PORT_OWNER) && wValue != USB_PORT_FEAT_POWER)
break;
switch (wValue) {
@@ -510,7 +510,7 @@
goto error;
wIndex--;
temp = readl (&ehci->regs->port_status [wIndex]);
- if (temp & PORT_OWNER)
+ if ((temp & PORT_OWNER) && wValue != USB_PORT_FEAT_POWER)
break;
temp &= ~PORT_RWC_BITS;
diff -ruN linux-2.6.18/drivers/usb/host/ohci-hcd.c
linux-2.6.18-modified/drivers/usb/host/ohci-hcd.c
--- linux-2.6.18/drivers/usb/host/ohci-hcd.c 2006-09-20
06:42:06.000000000 +0300
+++ linux-2.6.18-modified/drivers/usb/host/ohci-hcd.c 2006-11-30
13:05:27.000000000 +0200
@@ -666,6 +666,11 @@
temp |= RH_A_NPS;
ohci_writel (ohci, temp, &ohci->regs->roothub.a);
}
+
+ temp &= ~(RH_A_NPS | RH_A_NOCP);
+ temp |= RH_A_PSM | RH_A_OCPM;
+ ohci_writel (ohci, temp, &ohci->regs->roothub.a);
+
ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status);
ohci_writel (ohci, (temp & RH_A_NPS) ? 0 : RH_B_PPCM,
&ohci->regs->roothub.b);
diff -ruN linux-2.6.18/drivers/usb/host/ohci-hub.c
linux-2.6.18-modified/drivers/usb/host/ohci-hub.c
--- linux-2.6.18/drivers/usb/host/ohci-hub.c 2006-09-20
06:42:06.000000000 +0300
+++ linux-2.6.18-modified/drivers/usb/host/ohci-hub.c 2006-11-30
13:16:25.000000000 +0200
@@ -559,6 +559,9 @@
break;
case USB_PORT_FEAT_POWER:
temp = RH_PS_LSDA;
+ ohci_writel (ohci, temp,
&ohci->regs->roothub.portstatus[wIndex]);
+ ohci_readl (ohci,
&ohci->regs->roothub.portstatus[wIndex]);
+ temp = RH_PS_CSC | RH_PS_PESC;
break;
case USB_PORT_FEAT_C_CONNECTION:
temp = RH_PS_CSC;
JR
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