From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Hk0g/rHG" Received: from mail-oa1-x32.google.com (mail-oa1-x32.google.com [IPv6:2001:4860:4864:20::32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 559881724 for ; Fri, 8 Dec 2023 07:48:53 -0800 (PST) Received: by mail-oa1-x32.google.com with SMTP id 586e51a60fabf-1fb14047fe7so1570483fac.1 for ; Fri, 08 Dec 2023 07:48:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702050532; x=1702655332; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CvGIaRZZrGiaN7WfHKadaS8JLhBTOynXGjwIgWbiLpA=; b=Hk0g/rHGHYSQfcIYm+KV4I2ZCE6NCf3zyUwLnyRwfrIP0NG9M/49zAjm8UddA8EVHN SOF01yYZQiPReOJoxMA0ZBRjv8LC5A8DhFYun8lMyXK2VxtLZNFyedIzpXQsXqZi/V6e 79MfHNKQ9Mt06srDPqw8wGPYGSUBYHqi/N3indW85tlH38agtH6FstZLBs8a44+fdK5J v714wkkpirF/CR6YMNMURC+/NboGsqNIsZRFhFpZ3+vuhom2Zg5H+btW5/RuLxcuEHjL VAxRCGcSiEtkuj6zLeOxQO7TQ+zQtQoIZj/3DdE8Co/C6V/gJ9+HsNJyxmjLDjyj+H51 6gmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702050532; x=1702655332; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CvGIaRZZrGiaN7WfHKadaS8JLhBTOynXGjwIgWbiLpA=; b=ViIbVIApHcLiBYEhtjFALIWCImROjRCYlFZQ+ra7yBNhz48220QHkQUG50lsivNJ7B X3b5ofpIJ5IKXEfX1ptOH+P4Cxm8dpBScD+GZIwMsB/VEWkUK7DeIMC8SyLaFCwIu5kN 9p04D/UrJT8KSJchDgVKKptYJw96cbIcKeT7JNFkmJTTyD1+SasCom1Y1n8z/ftM0WC9 VqlNTZYulYiXI5nRhaCq22Q0DXUCBcq+Qvk5fYWfKKEYOn2Yg/bCHZXlgfU/LUch2LG1 6Ahrp3gn5jbQku/e3zRJoBavHwXh7f5+btV8WQObhb62oTMync3E///A9PoL42YjNElI 5O0A== X-Gm-Message-State: AOJu0Yxhh9OPlnuqVtE+tebmlzdHgdRq9DDU3xM//mNC9nIJN5SRyL5D ojjg5w+4GrWvULbJN5yxkMa5VJUdfsA= X-Google-Smtp-Source: AGHT+IFcyiv07XisAWrr55TzlRfXp9Mk8AGnaOZAaI0YTkOm5TiqFGi/N32KJ7yt9vjPxevz2v9OTA== X-Received: by 2002:a05:6870:4723:b0:1fa:477:8a93 with SMTP id b35-20020a056870472300b001fa04778a93mr511508oaq.24.1702050532411; Fri, 08 Dec 2023 07:48:52 -0800 (PST) Received: from localhost.localdomain ([75.28.21.198]) by smtp.gmail.com with ESMTPSA id os25-20020a0568707d1900b001fb28cd0e9asm444624oab.3.2023.12.08.07.48.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Dec 2023 07:48:52 -0800 (PST) From: Chris Morgan To: devicetree@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, linus.walleij@linaro.org, marex@denx.de, conor+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, robh+dt@kernel.org, daniel@ffwll.ch, airlied@gmail.com, sam@ravnborg.org, quic_jesszhan@quicinc.com, neil.armstrong@linaro.org, jagan@amarulasolutions.com, Chris Morgan Subject: [PATCH 1/3] drm/panel: st7701: Fix AVCL calculation Date: Fri, 8 Dec 2023 09:48:45 -0600 Message-Id: <20231208154847.130615-2-macroalpha82@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231208154847.130615-1-macroalpha82@gmail.com> References: <20231208154847.130615-1-macroalpha82@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chris Morgan The AVCL register, according to the datasheet, comes in increments of -0.2v between -4.4v (represented by 0x0) to -5.0v (represented by 0x3). The current calculation is done by adding the defined AVCL value in mV to -4400 and then dividing by 200 to get the register value. Unfortunately if I subtract -4400 from -4400 I get -8800, which divided by 200 gives me -44. If I instead subtract -4400 from -4400 I get 0, which divided by 200 gives me 0. Based on the datasheet this is the expected register value. Fixes: 83b7a8e7e88e ("drm/panel/panel-sitronix-st7701: Parametrize voltage and timing") Signed-off-by: Chris Morgan --- drivers/gpu/drm/panel/panel-sitronix-st7701.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7701.c b/drivers/gpu/drm/panel/panel-sitronix-st7701.c index 0459965e1b4f..036ac403ed21 100644 --- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c +++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c @@ -288,7 +288,7 @@ static void st7701_init_sequence(struct st7701 *st7701) FIELD_PREP(DSI_CMD2_BK1_PWRCTRL2_AVDD_MASK, DIV_ROUND_CLOSEST(desc->avdd_mv - 6200, 200)) | FIELD_PREP(DSI_CMD2_BK1_PWRCTRL2_AVCL_MASK, - DIV_ROUND_CLOSEST(-4400 + desc->avcl_mv, 200))); + DIV_ROUND_CLOSEST(-4400 - desc->avcl_mv, 200))); /* T2D = 0.2us * T2D[3:0] */ ST7701_DSI(st7701, DSI_CMD2_BK1_SPD1, -- 2.34.1