From patchwork Wed Dec 18 00:47:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 11299175 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 C248113B6 for ; Wed, 18 Dec 2019 00:48:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9567521835 for ; Wed, 18 Dec 2019 00:48:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="I1vPcKTz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbfLRAsg (ORCPT ); Tue, 17 Dec 2019 19:48:36 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:35110 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbfLRAsf (ORCPT ); Tue, 17 Dec 2019 19:48:35 -0500 Received: by mail-pl1-f194.google.com with SMTP id g6so176463plt.2 for ; Tue, 17 Dec 2019 16:48:33 -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=si3/aZxayWyxRtmbxBApJb8jBIUuiyY2NA4K59mZEjs=; b=I1vPcKTziCjSzpUpntR3WPkNkwwxVqSkesYgV1nXY4rDmZ+dphNINRv5omhsnvmw2m RNI2g/w7Z/rtDEe9IqxHx850lqY34FqBfIf9W8dBTPux2CJTFmX+xsRwg15uC80400wT JEXw2YJm7anCk8NrcAaJdlINcOOoeZugZtg1k= 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=si3/aZxayWyxRtmbxBApJb8jBIUuiyY2NA4K59mZEjs=; b=Lm+UOjQD0hWVq0029u70rSeb5/CH6BqpGaIPdidih1iSOB1CGZihHb8bSYs8qwVQ+v R5/+wXiIi3Y8w3qVtb0TFhyA/Ln41qujbU1s/1DypEINTaFJ9r+gaKqLdQQT3kkMKCbF IznvFJhvWgYgLDgNdqVcungAXNxqjty7pynZ2x7A8ZGKBRdcRLV2iTobKFjTahuRiCdJ uqHMwqfW3mMkmTOSgsH23rQKusnwcg+C0wNCw8e/+pTdlmseslNXUOmey/zC3s0B36VP RpzFY1q4gHyaz9bviLBCXn9anD43UPSsKQOI6zvVAQroLiAl4Hqo7DMfoUpI2JsAa8Yc keow== X-Gm-Message-State: APjAAAWQdVloUj5AGMf03Nz/ysa8StmfC+Z+LrH3TPhcRLmERm9IJBeM H68z38ppgUQ/tgHoclht4VNrqA== X-Google-Smtp-Source: APXvYqyU+DrDIYXKwJopWVnTcJrTm9iCZXee/CEelL/zaVEx5zgQtVdaftfoj2XLFYZuI3Dh1fO9kg== X-Received: by 2002:a17:90a:cb83:: with SMTP id a3mr220788pju.80.1576630113475; Tue, 17 Dec 2019 16:48:33 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:24fa:e766:52c9:e3b2]) by smtp.gmail.com with ESMTPSA id v72sm139885pjb.25.2019.12.17.16.48.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2019 16:48:32 -0800 (PST) From: Douglas Anderson To: Andrzej Hajda , Neil Armstrong Cc: robdclark@chromium.org, linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org, seanpaul@chromium.org, Jeffrey Hugo , Daniel Vetter , Douglas Anderson , Rob Clark , Jonas Karlman , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, David Airlie , Jernej Skrabec , Laurent Pinchart Subject: [PATCH v2 6/9] drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can Date: Tue, 17 Dec 2019 16:47:38 -0800 Message-Id: <20191217164702.v2.6.Iaf8d698f4e5253d658ae283d2fd07268076a7c27@changeid> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog In-Reply-To: <20191218004741.102067-1-dianders@chromium.org> References: <20191218004741.102067-1-dianders@chromium.org> MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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 Tested-by: Rob Clark Reviewed-by: Rob Clark --- Changes in v2: None 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,