[PATCH 2/4] usb: dwc3: Fix gadget pullup in SS mode
From: Felipe Balbi <hidden>
Date: 2012-09-19 11:58:01
Also in:
linux-devicetree, linux-omap, lkml
Hi, On Wed, Sep 19, 2012 at 05:00:27PM +0530, Kishon Vijay Abraham I wrote:
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.
quoted hunk ↗ jump to hunk
--- 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) 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 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20120919/74fd5591/attachment.sig>