From nobody Sun Feb 8 04:12:00 2026 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 7224922A4D8; Tue, 4 Nov 2025 14:31:10 +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=1762266670; cv=none; b=sNuJ3s6w8Am/eoeoQ5eZnkWPmKcFsdMfJvsJ7Hh1L3vrfY28acFx1LYA0PFnSbd3lh1OD0LSx1Pkzq1BMlMVpQQ68kD0vdz181F+BUC458Oy7537A35f169SZWa0DuGrYNBLTiIcIHw26m7c99dDyGhHzIz0KUJiCDVHrQIOfZA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762266670; c=relaxed/simple; bh=jlqi2q+tTuXwGck80ZW2V1ed+JWeA2LUWlef2Ygh8QE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=acCK3b9M96SQ53XYbKuVS+kwcSK4o+JLB9JKrpAqPnpRuiHUT2Zyvmt7/yP9Kw89z4Y5Inf9Gnb3vABvF3JuxoJIVuYo9Z+8HNbihW6J1s+VpgvQf2OpfBVVLEOLGngCPqLON8+dq51Aoc68x5aqdbVM4tZimiQaAMiVlDxO5GM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Bzf2drQI; 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="Bzf2drQI" Received: by smtp.kernel.org (Postfix) with ESMTPS id 0F01CC19424; Tue, 4 Nov 2025 14:31:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux.dev; s=korg; t=1762266670; bh=jlqi2q+tTuXwGck80ZW2V1ed+JWeA2LUWlef2Ygh8QE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Bzf2drQIDk3wwCeaREzyG2gThAcqn7bp5vOKd0FyhmxbkXH+O3NWOiWtvWthTaZbo NxHNdpYEMGxTAusX6oosPg1cWyimzPiG54Ll/kXHJ5xKaz41Hfrvv19GiqfozvM83L S93BrMfIrdinReYAoIjEEDqBfYAOfAXKtOxKOMYk= 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 06F04CCFA04; Tue, 4 Nov 2025 14:31:10 +0000 (UTC) From: Richard Leitner Date: Tue, 04 Nov 2025 15:30:58 +0100 Subject: [PATCH v8 7/8] 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: <20251104-ov9282-flash-strobe-v8-7-b91dfef1c65a@linux.dev> References: <20251104-ov9282-flash-strobe-v8-0-b91dfef1c65a@linux.dev> In-Reply-To: <20251104-ov9282-flash-strobe-v8-0-b91dfef1c65a@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 0.15-dev-509f5 X-Developer-Signature: v=1; a=ed25519-sha256; t=1762266668; l=3578; i=richard.leitner@linux.dev; s=20250225; h=from:subject:message-id; bh=jlqi2q+tTuXwGck80ZW2V1ed+JWeA2LUWlef2Ygh8QE=; b=GJOrayd8RROomQ2ExqSQeVFO9XHgz0Z8LVc4MaiKAQyC2iJgEjwv0N9GdBqfm+JHDjHG3qz7H 853xb3YBY6FDdSr1vUQnBZ5IvpSr5ERmq7HlsBAu59qR7e7yaS3mtCj 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 | 55 ++++++++++++++++++++++++++++++++++++++++++= +--- 1 file changed, 52 insertions(+), 3 deletions(-) diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c index 26296dc1d1b95..7aa74feb3ee44 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 */ @@ -691,9 +693,8 @@ static int ov9282_set_ctrl_flash_strobe_oe(struct ov928= 2 *ov9282, bool enable) return ov9282_write_reg(ov9282, OV9282_REG_OUTPUT_ENABLE6, 1, 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) { - int ret; /* * Calculate "strobe_frame_span" increments from a given value (=C2=B5s). * This is quite tricky as "The step width of shift and span is @@ -703,7 +704,28 @@ 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) +{ + int ret; + u32 val =3D ov9282_us_to_flash_duration(ov9282, value); =20 ret =3D ov9282_write_reg(ov9282, OV9282_REG_STROBE_FRAME_SPAN, 1, (val >> 24) & 0xff); @@ -798,9 +820,36 @@ 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_const(ctrl->handler, struct ov9282, ctrl_handler); + + if (ctrl->id =3D=3D V4L2_CID_FLASH_DURATION) { + u32 us =3D ctrl->val; + u32 fd =3D ov9282_us_to_flash_duration(ov9282, us); + + /* 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 2.47.3