From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB825C77B71 for ; Tue, 18 Apr 2023 07:40:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230424AbjDRHkp (ORCPT ); Tue, 18 Apr 2023 03:40:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbjDRHkn (ORCPT ); Tue, 18 Apr 2023 03:40:43 -0400 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A96223C1F for ; Tue, 18 Apr 2023 00:40:41 -0700 (PDT) Received: (Authenticated sender: me@crly.cz) by mail.gandi.net (Postfix) with ESMTPSA id D396EFF805; Tue, 18 Apr 2023 07:40:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crly.cz; s=gm1; t=1681803639; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=aPl7ACTbaf6Xi825bUFZ+ZDPrR2PqiPSSSG/kvCOI6A=; b=XdtnH+Ga3tmi0mjo+o7qTfYAfcy0q1ULx/84PvIl1J4116fLhnBuDh3Z84H93wZkY//f0y 4/bxPyKexMl2frjIzlUnOL+wv+V/mZjA2UO7QsTlPAjjd5LJTknc7OiCkJwX009uhoHZQX botK5leRdXmNHYEQygaHjHh40LhxRsEDYV9t7N2DMFTstDInax1/2dml3MVjQHmYlfuLgz rSaSa8VrA77glCtFFU+ZxS0EJterarKLjIOgkKaWiScRFVMs7FtQuxfkJe/JKPZDWrFplC Ra10K+ITElx+paoqAtuE2av+5rNyFltMzW8zDtOPJFzNvusrG/W4usDoZaCNlA== From: Roman Beranek To: Maxime Ripard , Chen-Yu Tsai , David Airlie , Daniel Vetter , Jernej Skrabec , Samuel Holland Cc: Roman Beranek , Frank Oltmanns , Icenowy Zheng , Ondrej Jirman , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v2 0/7] drm: sun4i: set proper TCON0 DCLK rate in DSI mode Date: Tue, 18 Apr 2023 09:40:01 +0200 Message-Id: <20230418074008.69752-1-me@crly.cz> X-Mailer: git-send-email 2.32.0 (Apple Git-132) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to Allwinner's BSP code, in DSI mode, TCON0 clock needs to be running at what's effectively the per-lane datarate of the DSI link. Given that the TCON DCLK divider is fixed to 4 (SUN6I_DSI_TCON_DIV), DCLK can't be set equal to the dotclock. Therefore labeling TCON DCLK as sun4i_dotclock or tcon-pixel-clock shall be avoided. With bpp bits per pixel transmitted over n DSI lanes, the target DCLK rate for a given pixel clock is obtained as follows: DCLK rate = 1/4 * bpp / n * pixel clock Effect of this change can be observed through the rate of Vblank IRQs which should now match refresh rate implied by set display mode. It was verified to do so on a A64 board with a 2-lane and a 4-lane panel. v2: 1. prevent reparent of tcon0 to pll-video0-2x 2. include pll-video0 in setting TCON0 DCLK rate 3. tested the whole thing also on a PinePhone Roman Beranek (7): clk: sunxi-ng: a64: propagate rate change from pll-mipi clk: sunxi-ng: a64: export PLL_MIPI clk: sunxi-ng: a64: prevent CLK_TCON0 being reparented arm64: dts: allwinner: a64: assign PLL_MIPI to CLK_TCON0 ARM: dts: sunxi: rename tcon's clock output drm: sun4i: rename sun4i_dotclock to sun4i_tcon_dclk drm: sun4i: calculate proper DCLK rate for DSI arch/arm/boot/dts/sun5i.dtsi | 2 +- arch/arm/boot/dts/sun8i-a23-a33.dtsi | 2 +- arch/arm/boot/dts/sun8i-a83t.dtsi | 2 +- arch/arm/boot/dts/sun8i-v3s.dtsi | 2 +- arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 4 +- drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 6 ++- drivers/clk/sunxi-ng/ccu-sun50i-a64.h | 4 +- drivers/gpu/drm/sun4i/Makefile | 2 +- drivers/gpu/drm/sun4i/sun4i_tcon.c | 46 +++++++++++-------- .../{sun4i_dotclock.c => sun4i_tcon_dclk.c} | 2 +- .../{sun4i_dotclock.h => sun4i_tcon_dclk.h} | 0 include/dt-bindings/clock/sun50i-a64-ccu.h | 1 + 12 files changed, 43 insertions(+), 30 deletions(-) rename drivers/gpu/drm/sun4i/{sun4i_dotclock.c => sun4i_tcon_dclk.c} (99%) rename drivers/gpu/drm/sun4i/{sun4i_dotclock.h => sun4i_tcon_dclk.h} (100%) base-commit: 4aa35a0130d6b8afbefc9ef530a521fb0fb9b8e1 -- 2.34.1