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SubjectRe: [PATCH 2/4] usb: dwc3: Fix gadget pullup in SS mode
Hi,

On Wed, Sep 19, 2012 at 05:00:27PM +0530, Kishon Vijay Abraham I wrote:
> From: Moiz Sonasath <m-sonasath@ti.com>
>
> 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 <m-sonasath@ti.com>
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

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.

> ---
> 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
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