usb: chipidea: add ttctrl.ttha control interface

The register of ttctrl.ttha describes like below:
- Internal TT Hub Address Representation
- RW
- Default = 0000000b
This field is used to match against the Hub Address field in QH & siTD
to determine if the packet is routed to the internal TT for directly
attached FS/LS devices. If the Hub Address in the QH or siTD does not
match this address then the packet will be broadcast on the High Speed
ports destined for a downstream High Speed hub with the address in the QH/siTD.

In silicon RTL, this entry only affects QH and siTD, and the hub.addr at
both QH and siTD are 0 in ehci core for chipidea (with hcd->has_tt = 1).

So, for QH, if the "usage_tt" flag at RTL is 0, set CI_HDRC_SET_NON_ZERO_TTHA
will not affect QH (with non-hs device); for siTD, set this flag
will change remaining space requirement for the last transaction from 1023
bytes to 188 bytes, it can increase the number of transactions within one
frame, ehci periodic schedule code will not queue the packet if the frame space
is full, so it is safe to set this flag for siTD.

With this flag, it can fix the problem Alan Stern reported below:
http://www.spinics.net/lists/linux-usb/msg123125.html
And may fix Michael Tessier's problem too.
http://www.spinics.net/lists/linux-usb/msg118679.html

CC: stern@rowland.harvard.edu
CC: michael.tessier@axiontech.ca
Signed-off-by: Peter Chen <peter.chen@freescale.com>

4 files changed, 11 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/bits.h b/drivers/usb/chipidea/bits.h
index 3cb9bda51ddf..831a8f645ea5 100644
--- a/drivers/usb/chipidea/bits.h
+++ b/drivers/usb/chipidea/bits.h
@@ -53,6 +53,11 @@
 #define DEVICEADDR_USBADRA    BIT(24)
 #define DEVICEADDR_USBADR     (0x7FUL << 25)
 
+/* TTCTRL */
+#define TTCTRL_TTHA_MASK	(0x7fUL << 24)
+/* Set non-zero value for internal TT Hub address representation */
+#define TTCTRL_TTHA		(0x7fUL << 24)
+
 /* PORTSC */
 #define PORTSC_CCS            BIT(0)
 #define PORTSC_CSC            BIT(1)
diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index 6d6200e37b71..df57e49ed4ef 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -50,6 +50,7 @@ enum ci_hw_regs {
 	OP_USBINTR,
 	OP_DEVICEADDR,
 	OP_ENDPTLISTADDR,
+	OP_TTCTRL,
 	OP_PORTSC,
 	OP_DEVLC,
 	OP_OTGSC,
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 3ad48e1c0c57..b0d01f26cd5e 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -84,6 +84,7 @@ static const u8 ci_regs_nolpm[] = {
 	[OP_USBINTR]		= 0x08U,
 	[OP_DEVICEADDR]		= 0x14U,
 	[OP_ENDPTLISTADDR]	= 0x18U,
+	[OP_TTCTRL]		= 0x1CU,
 	[OP_PORTSC]		= 0x44U,
 	[OP_DEVLC]		= 0x84U,
 	[OP_OTGSC]		= 0x64U,
@@ -106,6 +107,7 @@ static const u8 ci_regs_lpm[] = {
 	[OP_USBINTR]		= 0x08U,
 	[OP_DEVICEADDR]		= 0x14U,
 	[OP_ENDPTLISTADDR]	= 0x18U,
+	[OP_TTCTRL]		= 0x1CU,
 	[OP_PORTSC]		= 0x44U,
 	[OP_DEVLC]		= 0x84U,
 	[OP_OTGSC]		= 0xC4U,
diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index 7161439def19..b01716c8c66b 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -159,6 +159,9 @@ static int host_start(struct ci_hdrc *ci)
 	if (ci->platdata->flags & CI_HDRC_FORCE_FULLSPEED)
 		hw_write(ci, OP_PORTSC, PORTSC_PFSC, PORTSC_PFSC);
 
+	if (ci->platdata->flags & CI_HDRC_SET_NON_ZERO_TTHA)
+		hw_write(ci, OP_TTCTRL, TTCTRL_TTHA_MASK, TTCTRL_TTHA);
+
 	return ret;
 
 disable_reg: