From nobody Fri Oct 3 12:25:00 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 68B9834AAE0; Mon, 1 Sep 2025 15:05:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756739147; cv=none; b=sXcelN8yA2ciyoRYygOosDcPr3KF2l0Js0eRpzTKgIjzBpV4sxjBBZxiO+ftUSXqsXHsgntqF3NI1QmVXZJLTAv4xJRv8CG56lgrp+hrtlSHq4/HJPBny8ezifmGePcDqIwQQg32/nMTxzGdJgOO3vfUSWq2yM45ZhefJQ5XdH8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756739147; c=relaxed/simple; bh=zpPHdpszebqthTo574ANivruP/PT3WTF/uH/e9F0K+Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nSDa8GfNXgb51Z634QVdUVJtb2xTd0COBzhmM9Rwuu+tiaXH7y4HRLQx/U9YOsetbRTHudLp4CC37SGM4PqvvhjPI1GEIMkHGNX83TmKMiEk2uTreq3kN+UHNkxgHmQSmToZ3R1T3M5aUSTbQqsam9AN7cLHlv5f80vs98yFU0w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=mIf25cQV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="mIf25cQV" Received: by smtp.kernel.org (Postfix) with ESMTPS id 02767C116C6; Mon, 1 Sep 2025 15:05:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux.dev; s=korg; t=1756739147; bh=zpPHdpszebqthTo574ANivruP/PT3WTF/uH/e9F0K+Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=mIf25cQV8ZhTdwMszcMm+F1rFA7t1pS9Wyl45cP3mzNddcK2tMoyB5byPfky9NY1v ama5ZVS3Ui3CeOiNgOjX//ue6qdyDSbXbnvEdEwAn/0zD+zkBeyPdJLdEl6jiA9p9z XRh5BX2O/2lguT+GIfaQZh668Up8JyRBCKZkezH4= Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE14ECA0FF0; Mon, 1 Sep 2025 15:05:46 +0000 (UTC) From: Richard Leitner Date: Mon, 01 Sep 2025 17:05:14 +0200 Subject: [PATCH v7 09/10] media: i2c: ov9282: implement try_ctrl for strobe_duration Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250901-ov9282-flash-strobe-v7-9-d58d5a694afc@linux.dev> References: <20250901-ov9282-flash-strobe-v7-0-d58d5a694afc@linux.dev> In-Reply-To: <20250901-ov9282-flash-strobe-v7-0-d58d5a694afc@linux.dev> To: Sakari Ailus , Dave Stevenson , Mauro Carvalho Chehab , Lee Jones , Pavel Machek , Laurent Pinchart Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, Richard Leitner , Hans Verkuil X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1756739145; l=3557; i=richard.leitner@linux.dev; s=20250225; h=from:subject:message-id; bh=zpPHdpszebqthTo574ANivruP/PT3WTF/uH/e9F0K+Q=; b=fdpLvNSFQTEl59tQ4YakjWj1z05zOCV+ppEi1wuerOUr0783No1fAR5HN5UemEDEp2sPKBg5T IUi4JPUzkgHAn4LjpaiRldZVANfx4P4WAnHDgSSEAIrMxjOUzoF+doI X-Developer-Key: i=richard.leitner@linux.dev; a=ed25519; pk=8hZNyyyQFqZ5ruVJsSGBSPIrmJpfDm5HwHU4QVOP1Pk= X-Endpoint-Received: by B4 Relay for richard.leitner@linux.dev/20250225 with auth_id=350 As the granularity of the hardware supported values is lower than the control value, implement a try_ctrl() function for V4L2_CID_FLASH_DURATION. This function calculates the nearest possible =C2=B5s strobe duration for the given value and returns it back to the caller. Signed-off-by: Richard Leitner --- drivers/media/i2c/ov9282.c | 54 ++++++++++++++++++++++++++++++++++++++++++= ++-- 1 file changed, 52 insertions(+), 2 deletions(-) diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c index 9efc82a1929a76c6fb245e7dbfb5276a133d1c5d..b104ae77f00e9e7777342e48b7b= f3caa6d297f69 100644 --- a/drivers/media/i2c/ov9282.c +++ b/drivers/media/i2c/ov9282.c @@ -128,6 +128,8 @@ #define OV9282_REG_MIN 0x00 #define OV9282_REG_MAX 0xfffff =20 +#define OV9282_STROBE_SPAN_FACTOR 192 + static const char * const ov9282_supply_names[] =3D { "avdd", /* Analog power */ "dovdd", /* Digital I/O power */ @@ -691,7 +693,7 @@ static int ov9282_set_ctrl_flash_hw_strobe_signal(struc= t ov9282 *ov9282, bool en current_val); } =20 -static int ov9282_set_ctrl_flash_duration(struct ov9282 *ov9282, u32 value) +static u32 ov9282_us_to_flash_duration(struct ov9282 *ov9282, u32 value) { /* * Calculate "strobe_frame_span" increments from a given value (=C2=B5s). @@ -702,7 +704,27 @@ static int ov9282_set_ctrl_flash_duration(struct ov928= 2 *ov9282, u32 value) * The formula below is interpolated from different modes/framerates * and should work quite well for most settings. */ - u32 val =3D value * 192 / (ov9282->cur_mode->width + ov9282->hblank_ctrl-= >val); + u32 frame_width =3D ov9282->cur_mode->width + ov9282->hblank_ctrl->val; + + return value * OV9282_STROBE_SPAN_FACTOR / frame_width; +} + +static u32 ov9282_flash_duration_to_us(struct ov9282 *ov9282, u32 value) +{ + /* + * As the calculation in ov9282_us_to_flash_duration uses an integer + * divison calculate in ns here to get more precision. Then check if + * we need to compensate that divison by incrementing the =C2=B5s result. + */ + u32 frame_width =3D ov9282->cur_mode->width + ov9282->hblank_ctrl->val; + u64 ns =3D value * 1000 * frame_width / OV9282_STROBE_SPAN_FACTOR; + + return DIV_ROUND_UP(ns, 1000); +} + +static int ov9282_set_ctrl_flash_duration(struct ov9282 *ov9282, u32 value) +{ + u32 val =3D ov9282_us_to_flash_duration(ov9282, value); =20 ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION, 1, (val >> 24) & 0xff= ); ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION + 1, 1, (val >> 16) & = 0xff); @@ -792,9 +814,37 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl) return ret; } =20 +static int ov9282_try_ctrl(struct v4l2_ctrl *ctrl) +{ + struct ov9282 *ov9282 =3D + container_of(ctrl->handler, struct ov9282, ctrl_handler); + + if (ctrl->id =3D=3D V4L2_CID_FLASH_DURATION) { + u32 fd =3D ov9282_us_to_flash_duration(ov9282, ctrl->val); + u32 us =3D ctrl->val; + + /* get nearest strobe_duration value */ + u32 us0 =3D ov9282_flash_duration_to_us(ov9282, fd); + u32 us1 =3D ov9282_flash_duration_to_us(ov9282, (fd + 1)); + + if (abs(us1 - us) < abs(us - us0)) + ctrl->val =3D us1; + else + ctrl->val =3D us0; + + if (us !=3D ctrl->val) { + dev_dbg(ov9282->dev, "using next valid strobe_duration %u instead of %u= \n", + ctrl->val, us); + } + } + + return 0; +} + /* V4l2 subdevice control ops*/ static const struct v4l2_ctrl_ops ov9282_ctrl_ops =3D { .s_ctrl =3D ov9282_set_ctrl, + .try_ctrl =3D ov9282_try_ctrl, }; =20 /** --=20 2.47.2