Felipe,

On Wed, Sep 19, 2012 at 6:53 AM, Felipe Balbi [off-list ref] wrote:

Hi,

On Wed, Sep 19, 2012 at 05:00:27PM +0530, Kishon Vijay Abraham I wrote:

quoted

From: Moiz Sonasath <redacted>

For the gadget pullup functionality to work in
SS mode it requires a particular sequence of
toggling the run-stop bit. Here is the required
sequence:

- Set DCTL[31]
- Clear DCTL[31]
- Clear OMAP5430_CONTROL_CORE__PHY_POWER_USB[14]
- Clear DCTL[8:5] = 0x00
- Set DCTL[8:5] = 0x05
- Wait 25 Ms
- Set DCTL[31]
- Set OMAP5430_CONTROL_CORE__PHY_POWER_USB[14]

Tested rigourously the gadget pull-up functionality
in bot HS and SS modes.

Signed-off-by: Moiz Sonasath <redacted>
Signed-off-by: Kishon Vijay Abraham I <redacted>

this needs to split into three patches:

add new poweron field, implement it on omap-usb3, use it on
dwc3/gadget.c

btw, I don't think the changes to run_stop bit are necessary and if they
are, that'd either be a silicon errata or it would've been mentioned on
the databook. I don't remember seeing that on the databook so I'm
assuming that this is caused by a bad use of the PHY.

Why that mdelay(25) ? why 25 ms ? That's quite a long time, actually.

Felipe, This is infact a HW bug that the Si-Val team did accept and gave us
this workaround sequence with the precise delay :-)

Supposedly this will be fixed in ES 2.0.

quoted

---
 drivers/usb/dwc3/gadget.c   |   21 +++++++++++++++------
 drivers/usb/phy/omap-usb3.c |   16 ++++++++++++++++
 include/linux/usb/phy.h     |   10 +++++++++-
 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 58fdfad..bcc0102 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c

@@ -49,6 +49,7 @@

 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>

 #include "core.h"
 #include "gadget.h"

@@ -1417,19 +1418,27 @@ static int dwc3_gadget_run_stop(struct dwc3

*dwc, int is_on)

quoted

      reg = dwc3_readl(dwc->regs, DWC3_DCTL);
      if (is_on) {
              if (dwc->revision <= DWC3_REVISION_187A) {
-                     reg &= ~DWC3_DCTL_TRGTULST_MASK;
-                     reg |= DWC3_DCTL_TRGTULST_RX_DET;
+                     reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
+                     dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+                     reg |= DWC3_DCTL_ULSTCHNG_RX_DETECT;
+                     dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+                     mdelay(25);
+                     reg |= DWC3_DCTL_RUN_STOP;
+                     dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+                     usb_phy_poweron(dwc->usb3_phy);
              }

-             if (dwc->revision >= DWC3_REVISION_194A)
+             if (dwc->revision >= DWC3_REVISION_194A) {
                      reg &= ~DWC3_DCTL_KEEP_CONNECT;
-             reg |= DWC3_DCTL_RUN_STOP;
+                     reg |= DWC3_DCTL_RUN_STOP;
+                     dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+             }
      } else {
              reg &= ~DWC3_DCTL_RUN_STOP;
+             dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+             usb_phy_shutdown(dwc->usb3_phy);
      }

-     dwc3_writel(dwc->regs, DWC3_DCTL, reg);

I'd prefer to hold all values on the variable and write only one.

--
balbi

-- 
Regards
Moiz Sonasath
Android Kernel Team