From patchwork Thu May 31 06:50:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 10440389 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 509CE6035E for ; Thu, 31 May 2018 06:50:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B335293DA for ; Thu, 31 May 2018 06:50:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 38DD92910E; Thu, 31 May 2018 06:50:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 79B5D2910E for ; Thu, 31 May 2018 06:50:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A9BD089DA6; Thu, 31 May 2018 06:50:38 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lelnx193.ext.ti.com (lelnx193.ext.ti.com [198.47.27.77]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0523189D99 for ; Thu, 31 May 2018 06:50:36 +0000 (UTC) Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by lelnx193.ext.ti.com (8.15.1/8.15.1) with ESMTP id w4V6oWJN021635; Thu, 31 May 2018 01:50:32 -0500 Received: from DFLE113.ent.ti.com (dfle113.ent.ti.com [10.64.6.34]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id w4V6oWf1024384; Thu, 31 May 2018 01:50:32 -0500 Received: from DFLE102.ent.ti.com (10.64.6.23) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1466.3; Thu, 31 May 2018 01:50:32 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE102.ent.ti.com (10.64.6.23) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1466.3 via Frontend Transport; Thu, 31 May 2018 01:50:32 -0500 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id w4V6oUfA021888; Thu, 31 May 2018 01:50:31 -0500 From: Tomi Valkeinen To: Subject: [PATCH] drm/omap: Implement workaround for DRA7 errata ID:i932 Date: Thu, 31 May 2018 09:50:16 +0300 Message-ID: <20180531065016.22717-1-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tomi Valkeinen , Venkateswara Rao Mandela , Laurent Pinchart Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Venkateswara Rao Mandela Description of DRA7 Errata i932: In rare circumstances DPLL_VIDEO1 and DPLL_VIDEO2 PLL's may not lock on the first attempt during DSS initialization. When this occurs, a subsequent attempt to relock the PLL will result in PLL successfully locking. This patch does the following as per the errata recommendation: - retries locking the PLL upto 20 times. - The time to wait for a PLL lock set to 1000 REFCLK cycles. We use usleep_range to wait for 1000 REFCLK cycles in the us range. This tight constraint is imposed as a lock later than 1000 REFCLK cycles may have high jitter. - Criteria for PLL lock is extended from check on just the PLL_LOCK bit to check on 6 PLL_STATUS bits. Silicon Versions Impacted: DRA71, DRA72, DRA74, DRA76 - All silicon revisions AM57x - All silicon revisions OMAP4/5 are not impacted by this errata Signed-off-by: Venkateswara Rao Mandela [tomi.valkeinen@ti.com: ported to v4.14] Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/omapdrm/dss/dss.h | 3 + drivers/gpu/drm/omapdrm/dss/pll.c | 73 +++++++++++++++++++++---- drivers/gpu/drm/omapdrm/dss/video-pll.c | 1 + 3 files changed, 67 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/dss/dss.h b/drivers/gpu/drm/omapdrm/dss/dss.h index 847c78ade024..9f9a700bb6d5 100644 --- a/drivers/gpu/drm/omapdrm/dss/dss.h +++ b/drivers/gpu/drm/omapdrm/dss/dss.h @@ -180,6 +180,9 @@ struct dss_pll_hw { /* DRA7 errata i886: use high N & M to avoid jitter */ bool errata_i886; + + /* DRA7 errata i932: retry pll lock on failure */ + bool errata_i932; }; struct dss_pll { diff --git a/drivers/gpu/drm/omapdrm/dss/pll.c b/drivers/gpu/drm/omapdrm/dss/pll.c index 078b0e8216c3..ff362b38bf0d 100644 --- a/drivers/gpu/drm/omapdrm/dss/pll.c +++ b/drivers/gpu/drm/omapdrm/dss/pll.c @@ -16,6 +16,7 @@ #define DSS_SUBSYS_NAME "PLL" +#include #include #include #include @@ -381,6 +382,22 @@ static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask) return -ETIMEDOUT; } +static bool pll_is_locked(u32 stat) +{ + /* + * Required value for each bitfield listed below + * + * PLL_STATUS[6] = 0 PLL_BYPASS + * PLL_STATUS[5] = 0 PLL_HIGHJITTER + * + * PLL_STATUS[3] = 0 PLL_LOSSREF + * PLL_STATUS[2] = 0 PLL_RECAL + * PLL_STATUS[1] = 1 PLL_LOCK + * PLL_STATUS[0] = 1 PLL_CTRL_RESET_DONE + */ + return ((stat & 0x6f) == 0x3); +} + int dss_pll_write_config_type_a(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo) { @@ -436,18 +453,54 @@ int dss_pll_write_config_type_a(struct dss_pll *pll, l = FLD_MOD(l, 0, 25, 25); /* M7_CLOCK_EN */ writel_relaxed(l, base + PLL_CONFIGURATION2); - writel_relaxed(1, base + PLL_GO); /* PLL_GO */ + if (hw->errata_i932) { + int cnt = 0; + u32 sleep_time; + const u32 max_lock_retries = 20; - if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) { - DSSERR("DSS DPLL GO bit not going down.\n"); - r = -EIO; - goto err; - } + /* + * Calculate wait time for PLL LOCK + * 1000 REFCLK cycles in us. + */ + sleep_time = DIV_ROUND_UP(1000*1000*1000, cinfo->fint); - if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) { - DSSERR("cannot lock DSS DPLL\n"); - r = -EIO; - goto err; + for (cnt = 0; cnt < max_lock_retries; cnt++) { + writel_relaxed(1, base + PLL_GO); /* PLL_GO */ + + /** + * read the register back to ensure the write is + * flushed + */ + readl_relaxed(base + PLL_GO); + + usleep_range(sleep_time, sleep_time + 5); + l = readl_relaxed(base + PLL_STATUS); + + if (pll_is_locked(l) && + !(readl_relaxed(base + PLL_GO) & 0x1)) + break; + + } + + if (cnt == max_lock_retries) { + DSSERR("cannot lock PLL\n"); + r = -EIO; + goto err; + } + } else { + writel_relaxed(1, base + PLL_GO); /* PLL_GO */ + + if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) { + DSSERR("DSS DPLL GO bit not going down.\n"); + r = -EIO; + goto err; + } + + if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) { + DSSERR("cannot lock DSS DPLL\n"); + r = -EIO; + goto err; + } } l = readl_relaxed(base + PLL_CONFIGURATION2); diff --git a/drivers/gpu/drm/omapdrm/dss/video-pll.c b/drivers/gpu/drm/omapdrm/dss/video-pll.c index 585ed94ccf17..cb46311f92c9 100644 --- a/drivers/gpu/drm/omapdrm/dss/video-pll.c +++ b/drivers/gpu/drm/omapdrm/dss/video-pll.c @@ -134,6 +134,7 @@ static const struct dss_pll_hw dss_dra7_video_pll_hw = { .has_refsel = true, .errata_i886 = true, + .errata_i932 = true, }; struct dss_pll *dss_video_pll_init(struct dss_device *dss,