On 10/28/2016 04:31 AM, Alexandre Bailon wrote:
On 10/27/2016 08:44 PM, David Lechner wrote:
On 10/27/2016 12:16 PM, David Lechner wrote:
On 10/26/2016 05:58 AM, Alexandre Bailon wrote:
Currently, the USB OTG of the da8xx doesn't work.
This series intend to fix them.
Change in v2:
* Fix the error path da8xx_musb_init()
Alexandre Bailon (3):
usb: musb: da8xx: Call earlier clk_prepare_enable()
phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround
usb: musb: da8xx: Only execute the OTG workaround when phy in OTG mode
drivers/phy/phy-da8xx-usb.c | 17 ++++++++++++-----
drivers/usb/musb/da8xx.c | 28 +++++++++++++++++++---------
2 files changed, 31 insertions(+), 14 deletions(-)
I have found another problem with peripheral mode. When we force
peripheral mode, the glue layer currently uses CFGCHIP2 to override the
VBUS and ID. This causes it to not be able to detect disconnection
because the VBUS is overridden.
How have you found it ? Does it cause any issues ?
I mean I had to enable traces to see that disconnect was not happening.
I am also using the device tree patch series. I specified dr_mode =
"peripheral" in my device tree because the device is only wired for use
as a peripheral port.
I have actually known about this issue for a long time. See
<https://github.com/ev3dev/ev3dev/issues/244> and
<http://e2e.ti.com/support/embedded/linux/f/354/p/65332/237094#2370942>
Here is a patch to fix the problem. I have tested this on LEGO
MINDSTORMS EV3 (AM1808). This works because the ID pin is internally
pulled up on the SoC, so we don't need to override it.
Actually, I'm wonder if that if not related to VBUS sensing.
May be we should set CFGCHIP2_VBDTCTEN in device mode.
Yes, as we discussed in another thread, we should set CFGCHIP2_VBDTCTEN
and CFGCHIP2_SESNDEN *always* regardless of mode. I still have the
problem described above with these two enabled if and only if we are
also setting CFGCHIP2_OTG_FORCE_PERIPHERAL.
---
diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index 2bc12a2..33daa3b 100644
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -374,9 +374,7 @@ static int da8xx_musb_set_mode(struct musb *musb, u8
musb_mode)
case MUSB_HOST: /* Force VBUS valid, ID = 0 */
phy_mode = PHY_MODE_USB_HOST;
break;
- case MUSB_PERIPHERAL: /* Force VBUS valid, ID = 1 */
- phy_mode = PHY_MODE_USB_DEVICE;
- break;
+ case MUSB_PERIPHERAL:
case MUSB_OTG: /* Don't override the VBUS/ID
comparators */
phy_mode = PHY_MODE_USB_OTG;
break;
---
If this works for other SoCs/boards, I think we should make this change.
If it doesn't work, we could work around the VBUS problem by polling
VBUSSENSE in CFGCHIP2. But, I like the simple solution above better.
I have realized that due to the way my device is wired, I can actually
use OTG mode and it will behave exactly as peripheral mode because the
ID pin is not connected. So, maybe this patch is not needed after all.
Actually, I'm sure that is related to ID
The ID pin on my device is not connected, so I don't think this has to
do with ID. It is always high (internally pulled up).
I have the same issue except the disconnect is called when I use the
OTG mode.
This is exactly the behavior I am seeing.
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