From patchwork Fri Dec 13 23:45:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 11291949 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EBDA2930 for ; Fri, 13 Dec 2019 23:46:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CB41C22527 for ; Fri, 13 Dec 2019 23:46:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Lp92qpj8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB41C22527 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A60236EE1F; Fri, 13 Dec 2019 23:46:22 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by gabe.freedesktop.org (Postfix) with ESMTPS id 960C86EE1C for ; Fri, 13 Dec 2019 23:46:11 +0000 (UTC) Received: by mail-pj1-x1043.google.com with SMTP id ca19so376512pjb.8 for ; Fri, 13 Dec 2019 15:46:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=B6LIeoTVZ0mSbD6IzEagXEecwbraqAgXImg4I6o6rHs=; b=Lp92qpj8fKawZZY2uN6T5piVEduUDjdzcCNQTjlLrHnzFSGrfbxAAfg7FieIRuqAFr uJ/fw8Hn4w+UrCrVZjMvHmVpyoxQ5MZhtFoIkJeyS7BzT2TXjjoY+tYcF0KrJoU7+/NZ vstBHEBCmCgKW7xCX1QkUikRPTkxntOPMGEaE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=B6LIeoTVZ0mSbD6IzEagXEecwbraqAgXImg4I6o6rHs=; b=KH06meI5NaK/pBenVeC6LKH1Q4limTPnFYN3imvM1kOvANuKs/icmW77BEaswXNZfL eJVRX397KAJcrBPHb6zu+kuaP4OarKyWYcVUO9/tjdJDNVo/ZAwzP/inOPz3f9TUnTWl Um7fggBGlm6gfOT4LiMIs23YouAkNfTvSjDq+0P9HUiNwIss/6POs3oTtQdeUuGE/qaW AvHUNdViOKsmrhs1Z+4+/k69E2Mu5ybQ7sFvXY8mQBo4ijesfTPWZ+SIGfMu8KuRzstV KoEB06XRkqutfxw0DEkBDPFg00XJn/H4re4u2R7taoOYnXaqhT8Gnsz3pqDGm+XyaR+r hsHA== X-Gm-Message-State: APjAAAXtjIAsycVbCSY0N6wqeIKr+6VhxYzCbanF+7k6suljE3FS23ZM kCfDlIlWBqvlj3j/jj1hkDNedg== X-Google-Smtp-Source: APXvYqxOJks8ZZgxLNYKvJKGtY58eWEkqLn6dZCZr5NmJLSRyIAXQFmyMNn3YHwby5HYWehJbWYFtw== X-Received: by 2002:a17:90b:8d6:: with SMTP id ds22mr2489968pjb.100.1576280770985; Fri, 13 Dec 2019 15:46:10 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:24fa:e766:52c9:e3b2]) by smtp.gmail.com with ESMTPSA id z19sm12282905pfn.49.2019.12.13.15.46.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Dec 2019 15:46:10 -0800 (PST) From: Douglas Anderson To: Andrzej Hajda , Neil Armstrong Subject: [PATCH 6/9] drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can Date: Fri, 13 Dec 2019 15:45:27 -0800 Message-Id: <20191213154448.6.Iaf8d698f4e5253d658ae283d2fd07268076a7c27@changeid> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog In-Reply-To: <20191213234530.145963-1-dianders@chromium.org> References: <20191213234530.145963-1-dianders@chromium.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robdclark@chromium.org, Jernej Skrabec , Jonas Karlman , David Airlie , linux-arm-msm@vger.kernel.org, Douglas Anderson , dri-devel@lists.freedesktop.org, bjorn.andersson@linaro.org, seanpaul@chromium.org, Laurent Pinchart , linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The current bridge driver always forced us to use 24 bits per pixel over the DP link. This is a waste if you are hooked up to a panel that only supports 6 bits per color or fewer, since in that case you ran run at 18 bits per pixel and thus end up at a lower DP clock rate. Let's support this. While at it, let's clean up the math in the function to avoid rounding errors (and round in the correct direction when we have to round). Numbers are sufficiently small (because mode->clock is in kHz) that we don't need to worry about integer overflow. Signed-off-by: Douglas Anderson --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 0fc9e97b2d98..d5990a0947b9 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -51,6 +51,7 @@ #define SN_ENH_FRAME_REG 0x5A #define VSTREAM_ENABLE BIT(3) #define SN_DATA_FORMAT_REG 0x5B +#define BPP_18_RGB BIT(0) #define SN_HPD_DISABLE_REG 0x5C #define HPD_DISABLE BIT(0) #define SN_AUX_WDATA_REG(x) (0x64 + (x)) @@ -436,6 +437,14 @@ static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata) regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val); } +static unsigned int ti_sn_bridge_get_bpp(struct ti_sn_bridge *pdata) +{ + if (pdata->connector.display_info.bpc <= 6) + return 18; + else + return 24; +} + /** * LUT index corresponds to register value and * LUT values corresponds to dp data rate supported @@ -447,21 +456,17 @@ static const unsigned int ti_sn_bridge_dp_rate_lut[] = { static void ti_sn_bridge_set_dp_rate(struct ti_sn_bridge *pdata) { - unsigned int bit_rate_mhz, dp_rate_mhz; + unsigned int bit_rate_khz, dp_rate_mhz; unsigned int i; struct drm_display_mode *mode = &pdata->bridge.encoder->crtc->state->adjusted_mode; - /* - * Calculate minimum bit rate based on our pixel clock. At - * the moment this driver never sets the DP_18BPP_EN bit in - * register 0x5b so we hardcode 24bpp. - */ - bit_rate_mhz = (mode->clock / 1000) * 24; + /* Calculate minimum bit rate based on our pixel clock. */ + bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata); /* Calculate minimum DP data rate, taking 80% as per DP spec */ - dp_rate_mhz = ((bit_rate_mhz / pdata->dp_lanes) * DP_CLK_FUDGE_NUM) / - DP_CLK_FUDGE_DEN; + dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM, + 1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN); for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++) if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz) @@ -550,6 +555,10 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG, CHA_DSI_LANES_MASK, val); + /* Set the DP output format (18 bpp or 24 bpp) */ + val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0; + regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val); + /* DP lane config */ val = DP_NUM_LANES(min(pdata->dp_lanes, 3)); regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,