From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0A5523F482B for ; Thu, 18 Jun 2026 12:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781785425; cv=none; b=W5LGP64VvoZBGJ6BlBVZt6q0G4sV15O4ci4QnJ/ZcP0qgatnSCdFLfJeZ1AK1x3g5Kq6UvDybCMRH0tcGX60RPeypTQQnr7w/l2GhJptinRePiXWyNuZljJjoGyFgcti3NPDx4UJtsUfzWOgw3CpCFWR0aCKHdYpFX6iJGuiyco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781785425; c=relaxed/simple; bh=C3Ue+0dp2+FFHE5z/WmC42l4yMuleDdXt8q4YWy72hE=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=kB/uuiZwUJIPFX8IE6ZNQn7d2rdT3nsms78os0Gw0np1Vnb663LYhdb9Yf9E/qs3uzCkQsUNZEWi2JkR0LjBc7YQ2iXYMZdA3kpX5OhQG+NJBIBrgMzGAddiqvW7ix5JPlGLc8DdN0ys2sJJKFMv4CUzlGdf3Ns5j8jho9o9nvU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=l6MfqIvB; arc=none smtp.client-ip=209.85.128.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="l6MfqIvB" Received: by mail-wm1-f51.google.com with SMTP id 5b1f17b1804b1-490bc6a7958so15386005e9.1 for ; Thu, 18 Jun 2026 05:23:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1781785422; x=1782390222; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:references:cc:to:subject:reply-to:from:user-agent :mime-version:date:message-id:from:to:cc:subject:date:message-id :reply-to; bh=D5FEcOXjp/hefaowFGFjzfPrPE1kEo+L375WErKUiNc=; b=l6MfqIvBk118YafTKVhdMD8lLT9xAO1GHwCCqAVv/auP80oDC9qR6TheKKXGBH6eVr sNDy7Q1AnPcSeM9Mi/ZVml6Ngmcc3waUiT2LKH/BXc65PHHW5qFVjugyNDlYcGS2xr0r JVVyGYOI7COycm/WggWIeDeW0iqa4XACTm3m9Nh7S2jXizci+ASmYIHMTlkjimKm6sSM nqQ3OMaBtyAwGYZU7CNRg3seMbF5XUne94auG3BXmvu+deSJ+mZlTNEOLPbKXJcKMquQ 149HQGE4o+cnG/O/TK/rCmauyVpWo3YbpR3Uu8np1364ejPtepmgpPT3g1ptFqbix58c Z4zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781785422; x=1782390222; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:references:cc:to:subject:reply-to:from:user-agent :mime-version:date:message-id:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=D5FEcOXjp/hefaowFGFjzfPrPE1kEo+L375WErKUiNc=; b=LnEHTLXLNnNGLwQeqWF8PkD5vhVvunEr3wxTIamyeIGCvX9V8yX0sQV5rrZLaYlNbv /jVhQMw71YL9pqwxih2Gwe+OuwHr2AmSex0IR5xR3BUivv1rP+wjX+rjVK8ATa++RPoI 6F9Z7TITWQANutFbgrs0okFY6LTma+v3EZA+KlourRH5muCEkXsnZ9K5o/Fvf2snGGto cI/A/AIXIFKCjlay9chzasLn3++BZZEV9y2JCIVcRSXkQSuQOo14/fk+wMHlbZ7yfOR+ cNHgh3e4QDqyBuFJlPwgQ441bTnJt1/fnM7noBvyfQeej7dV+rQbF++ASn3Y8QpKO4Yf TWTg== X-Forwarded-Encrypted: i=1; AFNElJ8x6P8rmHyorWJKRq6oYDBW5Dk2+22I0womiZbBf/gxqU/JJNuX9peoJ3vItHka/acM/qdlj8sRYR/Axvs=@vger.kernel.org X-Gm-Message-State: AOJu0YyRtGvTEiIpEKbXdzVNetScnL3LslLZ1hSKJt5lvd329UbdmH7z 76qr7PVHJC/qmXymausUK/EhqQsAFLZ+2//LQ2GauWu4LE+TI6CuQ2w1dRJU6TaYOMU= X-Gm-Gg: AfdE7cmIDJL0BDi1MVWYkJsd7hoO7gNyDtgF6lwCLcBQ004FtPhry0cPR6HazYRR5fm 9wrHUela8HnLFE5lR/KqEmzm/X+IZ4mS6YDzCoku1zqn3fd7L84MIirnydtcxxczzwlr/tW8tzz 90fvTCVy9vOE/rb4zr4AGRcQSXhA13qPXee4bPkyYdeXwBKE64dnuercYzkN6jttI8lp9h5qORs Jsx+AaaaTsLRY+JP/37Ki0yissxeR1vWFaCi4JvI1vqMUV1Mw2MaE1qGX/e5h5GS31N5u+WRHCB HwRjYLgRhV33KPWO0tnI9eE9WmU5q5vLTzW9MDvdnKI/FLdfDPOwiFJ/ymGAlKUFSpr4rTTeByf 96zmeJ0ElER95KCeUmyITaNt73JGyR6f2zn57bNXWx5FgnJIoFptR1fHGoONOt/ElrZcsNq1JpG TC/cI5ylQjgHAdmVqV3tJD73wbRFTeN0cmbejlgIR4HDHJ8lebygfgD1SaR8FaL6RdWg== X-Received: by 2002:a7b:c8d3:0:b0:492:1e36:9a90 with SMTP id 5b1f17b1804b1-492381a2e79mr37585935e9.18.1781785422212; Thu, 18 Jun 2026 05:23:42 -0700 (PDT) Received: from ?IPV6:2a01:e0a:106d:1080:6e1b:5a5:b2b5:b2c0? ([2a01:e0a:106d:1080:6e1b:5a5:b2b5:b2c0]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4922fa96f0esm274863325e9.12.2026.06.18.05.23.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Jun 2026 05:23:41 -0700 (PDT) Message-ID: <716f71ae-4642-4f22-8a9f-5b1c017d9ac2@linaro.org> Date: Thu, 18 Jun 2026 14:23:40 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Neil Armstrong Reply-To: Neil Armstrong Subject: Re: [PATCH 3/3] drm/panel: himax-hx83121a: add backlight regulator support To: Icenowy Zheng , Jessica Zhang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Pengyu Luo Cc: Liam Girdwood , Mark Brown , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260608162622.403713-1-zhengxingda@iscas.ac.cn> <20260608162622.403713-3-zhengxingda@iscas.ac.cn> Content-Language: en-US, fr Autocrypt: addr=neil.armstrong@linaro.org; keydata= xsBNBE1ZBs8BCAD78xVLsXPwV/2qQx2FaO/7mhWL0Qodw8UcQJnkrWmgTFRobtTWxuRx8WWP GTjuhvbleoQ5Cxjr+v+1ARGCH46MxFP5DwauzPekwJUD5QKZlaw/bURTLmS2id5wWi3lqVH4 BVF2WzvGyyeV1o4RTCYDnZ9VLLylJ9bneEaIs/7cjCEbipGGFlfIML3sfqnIvMAxIMZrvcl9 qPV2k+KQ7q+aXavU5W+yLNn7QtXUB530Zlk/d2ETgzQ5FLYYnUDAaRl+8JUTjc0CNOTpCeik 80TZcE6f8M76Xa6yU8VcNko94Ck7iB4vj70q76P/J7kt98hklrr85/3NU3oti3nrIHmHABEB AAHNKk5laWwgQXJtc3Ryb25nIDxuZWlsLmFybXN0cm9uZ0BsaW5hcm8ub3JnPsLAkQQTAQoA OwIbIwULCQgHAwUVCgkICwUWAgMBAAIeAQIXgBYhBInsPQWERiF0UPIoSBaat7Gkz/iuBQJk Q5wSAhkBAAoJEBaat7Gkz/iuyhMIANiD94qDtUTJRfEW6GwXmtKWwl/mvqQtaTtZID2dos04 YqBbshiJbejgVJjy+HODcNUIKBB3PSLaln4ltdsV73SBcwUNdzebfKspAQunCM22Mn6FBIxQ GizsMLcP/0FX4en9NaKGfK6ZdKK6kN1GR9YffMJd2P08EO8mHowmSRe/ExAODhAs9W7XXExw UNCY4pVJyRPpEhv373vvff60bHxc1k/FF9WaPscMt7hlkbFLUs85kHtQAmr8pV5Hy9ezsSRa GzJmiVclkPc2BY592IGBXRDQ38urXeM4nfhhvqA50b/nAEXc6FzqgXqDkEIwR66/Gbp0t3+r yQzpKRyQif3OwE0ETVkGzwEIALyKDN/OGURaHBVzwjgYq+ZtifvekdrSNl8TIDH8g1xicBYp QTbPn6bbSZbdvfeQPNCcD4/EhXZuhQXMcoJsQQQnO4vwVULmPGgtGf8PVc7dxKOeta+qUh6+ SRh3vIcAUFHDT3f/Zdspz+e2E0hPV2hiSvICLk11qO6cyJE13zeNFoeY3ggrKY+IzbFomIZY 4yG6xI99NIPEVE9lNBXBKIlewIyVlkOaYvJWSV+p5gdJXOvScNN1epm5YHmf9aE2ZjnqZGoM Mtsyw18YoX9BqMFInxqYQQ3j/HpVgTSvmo5ea5qQDDUaCsaTf8UeDcwYOtgI8iL4oHcsGtUX oUk33HEAEQEAAcLAXwQYAQIACQUCTVkGzwIbDAAKCRAWmrexpM/4rrXiB/sGbkQ6itMrAIfn M7IbRuiSZS1unlySUVYu3SD6YBYnNi3G5EpbwfBNuT3H8//rVvtOFK4OD8cRYkxXRQmTvqa3 3eDIHu/zr1HMKErm+2SD6PO9umRef8V82o2oaCLvf4WeIssFjwB0b6a12opuRP7yo3E3gTCS KmbUuLv1CtxKQF+fUV1cVaTPMyT25Od+RC1K+iOR0F54oUJvJeq7fUzbn/KdlhA8XPGzwGRy 4zcsPWvwnXgfe5tk680fEKZVwOZKIEuJC3v+/yZpQzDvGYJvbyix0lHnrCzq43WefRHI5XTT QbM0WUIBIcGmq38+OgUsMYu4NzLu7uZFAcmp6h8g Organization: Linaro In-Reply-To: <20260608162622.403713-3-zhengxingda@iscas.ac.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/8/26 18:26, Icenowy Zheng wrote: > The backlight, when managed by the panel controller, could be powered by > an external regulator, and shutting down the regulator could power off > the backlight. > > Add support for such a regulator. It's powered off when the backlight is > 0 (either by setting brightness to 0 or setting bl_power), and powered > on when the backlight should be operating. > > Signed-off-by: Icenowy Zheng > --- > drivers/gpu/drm/panel/panel-himax-hx83121a.c | 26 ++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/drivers/gpu/drm/panel/panel-himax-hx83121a.c b/drivers/gpu/drm/panel/panel-himax-hx83121a.c > index 1a7e0125bced8..e31e2fba0a787 100644 > --- a/drivers/gpu/drm/panel/panel-himax-hx83121a.c > +++ b/drivers/gpu/drm/panel/panel-himax-hx83121a.c > @@ -34,7 +34,9 @@ struct himax { > struct drm_dsc_config dsc; > struct gpio_desc *reset_gpio; > struct regulator_bulk_data *supplies; > + struct regulator *bl_supply; > struct backlight_device *backlight; > + bool backlight_enabled; > }; > > struct panel_desc { > @@ -195,7 +197,27 @@ static int himax_bl_update_status(struct backlight_device *bl) > { > struct himax *ctx = bl_get_data(bl); > u16 brightness = backlight_get_brightness(bl); > + int ret = 0; > + > + if (!brightness) { > + if (ctx->backlight_enabled) > + ret = regulator_disable(ctx->bl_supply); > + if (ret) > + return ret; > + > + ctx->backlight_enabled = false; > + > + return 0; > + } > + > /* TODO: brightness to raw map table */ > + if (!ctx->backlight_enabled) > + ret = regulator_enable(ctx->bl_supply); > + if (ret) > + return ret; > + > + ctx->backlight_enabled = true; > + > return mipi_dsi_dcs_set_display_brightness_large(to_primary_dsi(ctx), > brightness); > } > @@ -647,6 +669,10 @@ static int himax_probe(struct mipi_dsi_device *dsi) > ctx->panel.prepare_prev_first = true; > > if (desc->has_dcs_backlight) { > + ctx->bl_supply = devm_regulator_get_optional(dev, "bl"); > + if (IS_ERR(ctx->bl_supply)) > + return dev_err_probe(dev, PTR_ERR(ctx->bl_supply), > + "Failed to get backlight supply\n"); > ctx->backlight = himax_create_backlight(ctx); > if (IS_ERR(ctx->backlight)) > return dev_err_probe(dev, PTR_ERR(ctx->backlight), Reviewed-by: Neil Armstrong Thanks, Neil