On 9 Feb 2009, Syed Ismail wrote:
> Hi
> I am running ehci on a mx31 ads high speed port. There is no uhci or
> ohci enabled. Some of our boards have problems running at high speed.
> These boards, when made to operate at full speed by using a 1.1
> external hub, work fine. Since, the only use of the usb port is to
> transfer a maximum of 4 MB of data, our needs would be met with full
> speed itself.
> The glue for ehci has been provided by freescale in their BSP.
>
> Can anyone suggest a way whereby i can configure devices to run only
> at full speed, even if they are high speed devices. By googling, i
> found that this can by done by sysfs interface, by writing the port
> number in a companion file. But, CONFIG_USB_EHCI_ROOT_HUB_TT is
> enabled and so the companion file is not created.By looking at code,
> I think companion file will get created if i disable this option. But
> will this work, as there is no uhci or ohci? What exactly are
> companion controllers.
>
> Is there a way i can make changes in ehci itself so that it will work
> only in full speed or low speed mode. Please help.
Here's an old experimental patch I wrote to add support for the
"companion" file for controllers using the ARC/TDI technology. It
needs to be cleaned up, and it undoubtedly needs some adjusting before
it will apply to recent kernels.
Alan Stern
Index: usb-2.6/drivers/usb/host/ehci.h
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci.h
+++ usb-2.6/drivers/usb/host/ehci.h
@@ -678,6 +678,13 @@ struct ehci_fstn {
* needed (mostly in root hub code).
*/
+/* Additions to the PORTSC registers */
+#define PORT_PSPD_FULL (0<<26)
+#define PORT_PSPD_LOW (1<<26)
+#define PORT_PSPD_HIGH (2<<26)
+#define PORT_PSPD_MASK (3<<26) /* port speed */
+#define PORT_PFSC (1<<24) /* port force full-speed connect */
+
#define ehci_is_TDI(e) ((e)->is_tdi_rh_tt)
/* Returns the speed of a device attached to a port on the root hub. */
@@ -685,12 +692,12 @@ static inline unsigned int
ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc)
{
if (ehci_is_TDI(ehci)) {
- switch ((portsc>>26)&3) {
- case 0:
+ switch (portsc & PORT_PSPD_MASK) {
+ case PORT_PSPD_FULL:
return 0;
- case 1:
+ case PORT_PSPD_LOW:
return (1<<USB_PORT_FEAT_LOWSPEED);
- case 2:
+ case PORT_PSPD_HIGH:
default:
return (1<<USB_PORT_FEAT_HIGHSPEED);
}
@@ -698,11 +705,19 @@ ehci_port_speed(struct ehci_hcd *ehci, u
return (1<<USB_PORT_FEAT_HIGHSPEED);
}
+/* Which bit controls whether a connection will be high-speed? */
+static inline u32 ehci_port_owner_bit(struct ehci_hcd *ehci)
+{
+ return ehci_is_TDI(ehci) ? PORT_PFSC : PORT_OWNER;
+}
+
+
#else
#define ehci_is_TDI(e) (0)
#define ehci_port_speed(ehci, portsc) (1<<USB_PORT_FEAT_HIGHSPEED)
+#define ehci_port_owner_bit(ehci) PORT_OWNER
#endif
/*-------------------------------------------------------------------------*/
Index: usb-2.6/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hub.c
+++ usb-2.6/drivers/usb/host/ehci-hub.c
@@ -309,13 +309,15 @@ static ssize_t show_companion(struct dev
}
/*
- * Sets the owner of a port
+ * Sets the connect-speed (i.e., owner) of a port
*/
-static void set_owner(struct ehci_hcd *ehci, int portnum, int new_owner)
+static void set_port_speed(struct ehci_hcd *ehci, int portnum, bool high_speed)
{
u32 __iomem *status_reg;
u32 port_status;
int try;
+ u32 owner_bit = ehci_port_owner_bit(ehci);
+ u32 new_owner = (high_speed ? 0 : owner_bit);
status_reg = &ehci->regs->port_status[portnum];
@@ -327,12 +329,17 @@ static void set_owner(struct ehci_hcd *e
for (try = 4; try > 0; --try) {
spin_lock_irq(&ehci->lock);
port_status = ehci_readl(ehci, status_reg);
- if ((port_status & PORT_OWNER) == new_owner
- || (port_status & (PORT_OWNER | PORT_CONNECT))
- == 0)
+ if ((port_status & owner_bit) == new_owner
+
+ /* If PORT_OWNER isn't set and the port is
+ * disconnected then stop (we can't set
+ * it unless a device is attached).
+ */
+ || ((port_status & (PORT_OWNER | PORT_CONNECT))
+ == 0 && !ehci_is_TDI(ehci))) {
try = 0;
- else {
- port_status ^= PORT_OWNER;
+ } else {
+ port_status ^= owner_bit;
port_status &= ~(PORT_PE | PORT_RWC_BITS);
ehci_writel(ehci, port_status, status_reg);
}
@@ -352,24 +359,24 @@ static ssize_t store_companion(struct de
const char *buf, size_t count)
{
struct ehci_hcd *ehci;
- int portnum, new_owner;
+ int portnum;
+ bool high_speed = false;
ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev)));
- new_owner = PORT_OWNER; /* Owned by companion */
if (sscanf(buf, "%d", &portnum) != 1)
return -EINVAL;
if (portnum < 0) {
portnum = - portnum;
- new_owner = 0; /* Owned by EHCI */
+ high_speed = true;
}
if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params))
return -ENOENT;
portnum--;
- if (new_owner)
- set_bit(portnum, &ehci->companion_ports);
- else
+ if (high_speed)
clear_bit(portnum, &ehci->companion_ports);
- set_owner(ehci, portnum, new_owner);
+ else
+ set_bit(portnum, &ehci->companion_ports);
+ set_port_speed(ehci, portnum, high_speed);
return count;
}
static DEVICE_ATTR(companion, 0644, show_companion, store_companion);
@@ -378,18 +385,13 @@ static inline void create_companion_file
{
int i;
- /* with integrated TT there is no companion! */
- if (!ehci_is_TDI(ehci))
- i = device_create_file(ehci_to_hcd(ehci)->self.dev,
- &dev_attr_companion);
+ i = device_create_file(ehci_to_hcd(ehci)->self.dev,
+ &dev_attr_companion);
}
static inline void remove_companion_file(struct ehci_hcd *ehci)
{
- /* with integrated TT there is no companion! */
- if (!ehci_is_TDI(ehci))
- device_remove_file(ehci_to_hcd(ehci)->self.dev,
- &dev_attr_companion);
+ device_remove_file(ehci_to_hcd(ehci)->self.dev, &dev_attr_companion);
}
@@ -420,7 +422,7 @@ static int check_reset_complete (
// what happens if HCS_N_CC(params) == 0 ?
port_status |= PORT_OWNER;
- port_status &= ~PORT_RWC_BITS;
+ port_status &= ~(PORT_RWC_BITS | PORT_CONNECT);
ehci_writel(ehci, port_status, status_reg);
} else
@@ -737,7 +739,8 @@ static int ehci_hub_control (
/* transfer dedicated ports to the companion hc */
if ((temp & PORT_CONNECT) &&
- test_bit(wIndex, &ehci->companion_ports)) {
+ test_bit(wIndex, &ehci->companion_ports) &&
+ !ehci_is_TDI(ehci)) {
temp &= ~PORT_RWC_BITS;
temp |= PORT_OWNER;
ehci_writel(ehci, temp, status_reg);
@@ -745,6 +748,16 @@ static int ehci_hub_control (
temp = ehci_readl(ehci, status_reg);
}
+ /* un-relinquish a disconnected port */
+ if (!(temp & PORT_CONNECT) &&
+ !test_bit(wIndex, &ehci->companion_ports) &&
+ ehci_is_TDI(ehci) &&
+ (temp & ehci_port_owner_bit(ehci))) {
+ temp &= ~(PORT_RWC_BITS | ehci_port_owner_bit(ehci));
+ ehci_writel(ehci, temp, status_reg);
+ temp = ehci_readl(ehci, status_reg);
+ }
+
/*
* Even if OWNER is set, there's no harm letting khubd
* see the wPortStatus values (they should all be 0 except
@@ -873,8 +886,5 @@ static void ehci_relinquish_port(struct
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
- if (ehci_is_TDI(ehci))
- return;
- set_owner(ehci, --portnum, PORT_OWNER);
+ set_port_speed(ehci, --portnum, false);
}
-
--
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