From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mslow1.mail.gandi.net (mslow1.mail.gandi.net [217.70.178.240]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95473156E0 for ; Fri, 5 May 2023 05:34:28 +0000 (UTC) Received: from relay8-d.mail.gandi.net (unknown [217.70.183.201]) by mslow1.mail.gandi.net (Postfix) with ESMTP id E2DD6C54D7 for ; Fri, 5 May 2023 05:21:34 +0000 (UTC) Received: (Authenticated sender: me@crly.cz) by mail.gandi.net (Postfix) with ESMTPSA id 440EA1BF20A; Fri, 5 May 2023 05:21:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crly.cz; s=gm1; t=1683264086; 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=GRdOoP7K5t1Qmrug0XJy+c34os7rpF7gVntp5bQK458=; b=MHUcTg5y6RwNfqDH4nhHg2jVT68SY2Ni30HE0C+0bJZIHv7pXGu7TP0auq613VAvcx7Atr nRpeaPT5xAVxBE+vcB1RsIgtNIoIz73PQC4hma+ndYr8wOga6YbQT5yaHXm0o9iVhiRIps oNEPiXY+wOU37gA/U3adL9J7Ush70ixMokIFaYqqSbUmNQIvWf1Rsj70ErsszCOloyBnAp MtUydyM7/eo3M4M4fj7fUf2O+zTb/9m5ieB3VPFkWipEhz7rt8Zd/wBMtwwqiURu207uJD nmxmyelyX+jSrtuoPEen50qWTCErqWoGtethnfymqSiNQnbPbSxtUAcfwGgNaw== From: Roman Beranek To: Maxime Ripard , David Airlie , Daniel Vetter , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski Cc: Frank Oltmanns , Icenowy Zheng , Ondrej Jirman , devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 0/4] drm: sun4i: set proper TCON0 DCLK rate in DSI mode Date: Fri, 5 May 2023 07:21:06 +0200 Message-Id: <20230505052110.67514-1-me@crly.cz> X-Mailer: git-send-email 2.32.0 (Apple Git-132) Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 v3: 1. accept that pll-video0 can't be included in setting TCON0 DCLK rate 2. reset pll-video0 to its default rate in case u-boot changed it v4: 1. keep pll-video0 as is 2. assign parent to TCON0 mux in sun50i_a64_ccu_probe (not in DT) Roman Beranek (4): clk: sunxi-ng: a64: force select PLL_MIPI in TCON0 mux 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 | 2 +- drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 14 +++++- 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 10 files changed, 46 insertions(+), 28 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: 8a91b29f1f50ce7742cdbe5cf11d17f128511f3f -- 2.32.0 (Apple Git-132)