Find whether we are running on newer silicon. The babble control register reads 0x4 by default in newer silicon as opposed to 0 in old versions of AM335x. Based on this enable the sw babble control logic.
Signed-off-by: George Cherian <george.cher...@ti.com> --- drivers/usb/musb/musb_dsps.c | 38 ++++++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-) diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c index 868caf8..2ced061 100644 --- a/drivers/usb/musb/musb_dsps.c +++ b/drivers/usb/musb/musb_dsps.c @@ -136,6 +136,7 @@ struct dsps_glue { const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */ struct timer_list timer; /* otg_workaround timer */ unsigned long last_timer; /* last timer data for each instance */ + bool sw_babble_enabled; struct dsps_context context; struct debugfs_regset32 regset; @@ -469,6 +470,19 @@ static int dsps_musb_init(struct musb *musb) val &= ~(1 << wrp->otg_disable); dsps_writel(musb->ctrl_base, wrp->phy_utmi, val); + /* + * Check whether the dsps version has babble control enabled. + * In latest silicon revision the babble control logic is enabled. + * If MUSB_BABBLE_CTL returns 0x4 then we have the babble control + * logic enabled. + */ + val = dsps_readb(musb->mregs, MUSB_BABBLE_CTL); + if (val == MUSB_BABBLE_RCV_DISABLE) { + glue->sw_babble_enabled = true; + val |= MUSB_BABBLE_SW_SESSION_CTRL; + dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, val); + } + ret = dsps_musb_dbg_init(musb, glue); if (ret) return ret; @@ -591,14 +605,26 @@ static int dsps_musb_reset(struct musb *musb) struct device *dev = musb->controller; struct dsps_glue *glue = dev_get_drvdata(dev->parent); const struct dsps_musb_wrapper *wrp = glue->wrp; + int session_restart = 0; - dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset)); - usleep_range(100, 200); - usb_phy_shutdown(musb->xceiv); - usleep_range(100, 200); - usb_phy_init(musb->xceiv); + if (glue->sw_babble_enabled) + session_restart = sw_babble_control(musb); + /* + * In case of new silicon version babble condition can be recovered + * without resetting the MUSB. But for older silicon versions, MUSB + * reset is needed + */ + if (session_restart || !glue->sw_babble_enabled) { + dev_info(musb->controller, "Restarting MUSB to recover from Babble\n"); + dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset)); + usleep_range(100, 200); + usb_phy_shutdown(musb->xceiv); + usleep_range(100, 200); + usb_phy_init(musb->xceiv); + session_restart = 1; + } - return 0; + return !session_restart; } static struct musb_platform_ops dsps_ops = { -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html