From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Cherian Subject: [PATCH v5 6/6] usb: musb: dsps: Enable sw babble control for newer silicon Date: Thu, 22 May 2014 11:59:41 +0530 Message-ID: <1400740181-31213-7-git-send-email-george.cherian@ti.com> References: <1400740181-31213-1-git-send-email-george.cherian@ti.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:47164 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752026AbaEVGbj (ORCPT ); Thu, 22 May 2014 02:31:39 -0400 In-Reply-To: <1400740181-31213-1-git-send-email-george.cherian@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org Cc: gregkh@linuxfoundation.org, balbi@ti.com, zonque@gmail.com, b-liu@ti.com, George Cherian 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 --- 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