On Mon, Dec 09, 2013 at 10:05:17AM +0100, Marc Kleine-Budde wrote:
> On 12/09/2013 07:31 AM, Peter Chen wrote:
> > After clear portsc.phcd, PHY needs 200us stable time for switch
> > 32K clock to AHB clock.
>
> If this is a general bugbix, please move it to the start of this series
> and add stable on Cc. I think I hit the bug on the second USB port of a
> custom MX28 board, the stmp_reset_block() in the USB phy will fail.
Not a bug-fix, just the requirement for the PHY leaves low power mode.
Does the bug exists with my this patchset, or just current mainline code?
>
> Is the problem documented somewhere?
>
> Is it possible to add the delay in the clock framework? I think only the
> regulator framework has a configurable delay for the regulator to stabilize.
It is just related to mxs PHY's hardware timing. It is better to add
it at specific driver.
Peter
>
> > Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
> > ---
> > drivers/usb/phy/phy-mxs-usb.c | 11 +++++++++++
> > 1 files changed, 11 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
> > index e18fdf3..7ae5225 100644
> > --- a/drivers/usb/phy/phy-mxs-usb.c
> > +++ b/drivers/usb/phy/phy-mxs-usb.c
> > @@ -151,6 +151,15 @@ static inline bool is_imx6sl_phy(struct mxs_phy *mxs_phy)
> > return mxs_phy->data == &imx6sl_phy_data;
> > }
> >
> > +/*
> > + * PHY needs some 32K cycles to switch from 32K clock to
> > + * bus (such as AHB/AXI, etc) clock.
> > + */
> > +static void mxs_phy_clock_switch(void)
> > +{
> > + usleep_range(300, 400);
> > +}
> > +
> > static int mxs_phy_hw_init(struct mxs_phy *mxs_phy)
> > {
> > int ret;
> > @@ -276,6 +285,7 @@ static int mxs_phy_init(struct usb_phy *phy)
> > {
> > struct mxs_phy *mxs_phy = to_mxs_phy(phy);
> >
> > + mxs_phy_clock_switch();
> > clk_prepare_enable(mxs_phy->clk);
> > return mxs_phy_hw_init(mxs_phy);
> > }
> > @@ -300,6 +310,7 @@ static int mxs_phy_suspend(struct usb_phy *x, int suspend)
> > x->io_priv + HW_USBPHY_CTRL_SET);
> > clk_disable_unprepare(mxs_phy->clk);
> > } else {
> > + mxs_phy_clock_switch();
> > clk_prepare_enable(mxs_phy->clk);
> > writel(BM_USBPHY_CTRL_CLKGATE,
> > x->io_priv + HW_USBPHY_CTRL_CLR);
> >
>
> Marc
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Industrial Linux Solutions | Phone: +49-231-2826-924 |
> Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
>
--
Best Regards,
Peter Chen
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