From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Mon, 09 Dec 2013 10:05:17 +0100 Subject: [PATCH v5 15/15] usb: phy-mxs: Add sync time after controller clear phcd In-Reply-To: <1386570664-6713-16-git-send-email-peter.chen@freescale.com> References: <1386570664-6713-1-git-send-email-peter.chen@freescale.com> <1386570664-6713-16-git-send-email-peter.chen@freescale.com> Message-ID: <52A587CD.7010203@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. 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. > Signed-off-by: Peter Chen > --- > 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 | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 259 bytes Desc: OpenPGP digital signature URL: