From patchwork Wed May 7 07:51:39 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Richard Leitner X-Patchwork-Id: 888727 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 5D370221708; Wed, 7 May 2025 07:52:22 +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=1746604342; cv=none; b=FRkGtFsGBYgRVn1Gv9rzr2nrIbkdTBXMGNadamLxlNdVQN0IO+tzbltJbHL6huL91y74TKfvPirpcCltQ37u+8aStqYXFW2B+E7CZ4K7hZXxceTd0NRrSVhKaCgTBFurSN4BteQ1jy4xebS6JSM9U7hvxWe3qRvVRTqQHUEoifQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746604342; c=relaxed/simple; bh=u2k9w+GukQmHB16zuirE+3M5ybc3Bh0/CkI9yc+9KRw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jvlDi515/sokttxdzO3oE2oeSAG9w1wE+1C+ubEf5ihYex43L6U240aEu3ALXd1EqXo4vsbe4wOWJu3WLWYjzrrvdwZm6caXYikoFR4yIdHdmRVxxciQQ12KAq7LovCZbvoD/py5JJadTTvYva3mHe5lzdwcdPL38cR9sjdeYAY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ShMWxKV9; 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="ShMWxKV9" Received: by smtp.kernel.org (Postfix) with ESMTPS id 03B2DC116B1; Wed, 7 May 2025 07:52:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux.dev; s=korg; t=1746604342; bh=u2k9w+GukQmHB16zuirE+3M5ybc3Bh0/CkI9yc+9KRw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ShMWxKV9AI5rOpsPspKoLO+DUIOItMSYj2ecYzesT3PwYi0AS+roJRtrxp1Gi6Jjq hY3Oe871ZK91Iy7R4hNtZ+f9UZ1jpQjjvO6Rm+PpNV3HRinNLGM/k2sNg8dShec8DB isc/Ax7x49IWLNGQg6E3npyQSxysh8FIb5hOZRMY= 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 F25D3C3ABC0; Wed, 7 May 2025 07:52:21 +0000 (UTC) From: Richard Leitner Date: Wed, 07 May 2025 09:51:39 +0200 Subject: [PATCH v4 10/10] media: i2c: ov9282: implement try_ctrl for strobe_duration Precedence: bulk X-Mailing-List: linux-leds@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250507-ov9282-flash-strobe-v4-10-72b299c1b7c9@linux.dev> References: <20250507-ov9282-flash-strobe-v4-0-72b299c1b7c9@linux.dev> In-Reply-To: <20250507-ov9282-flash-strobe-v4-0-72b299c1b7c9@linux.dev> To: Sakari Ailus , Dave Stevenson , Mauro Carvalho Chehab , Lee Jones , Pavel Machek , Laurent Pinchart Cc: Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, Richard Leitner X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1746604340; l=3563; i=richard.leitner@linux.dev; s=20250225; h=from:subject:message-id; bh=u2k9w+GukQmHB16zuirE+3M5ybc3Bh0/CkI9yc+9KRw=; b=N5Qmr+jFg9FjDlbZPon+ZQts18zYI0WCVHVozEDdHbQTS+N8S4mLLpcHEynAYMyRxvZCfOkkx sv0W2fUIVQdDc7j/UkTO8T9vZ5WoKZGXuomklIuDUEcAj9TxglnjqqO 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 µs strobe duration for the given value and returns it back to the caller. Signed-off-by: Richard Leitner --- drivers/media/i2c/ov9282.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 2 deletions(-) diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c index 09d522d5977ec6fb82028ddb6015f05c9328191d..f75882dcb73bea0e00e2cb37ffc19ec3c3a8b126 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 +#define OV9282_STROBE_SPAN_FACTOR 192 + static const char * const ov9282_supply_names[] = { "avdd", /* Analog power */ "dovdd", /* Digital I/O power */ @@ -691,7 +693,7 @@ static int ov9282_set_ctrl_flash_led_mode(struct ov9282 *ov9282, int mode) current_val); } -static int ov9282_set_ctrl_flash_duration(struct ov9282 *ov9282, int value) +static u32 ov9282_us_to_flash_duration(struct ov9282 *ov9282, u32 value) { /* * Calculate "strobe_frame_span" increments from a given value (µs). @@ -702,7 +704,31 @@ static int ov9282_set_ctrl_flash_duration(struct ov9282 *ov9282, int value) * The formula below is interpolated from different modes/framerates * and should work quite well for most settings. */ - u32 val = value * 192 / (ov9282->cur_mode->width + ov9282->hblank_ctrl->val); + u32 frame_width = 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 µs result. + */ + u32 frame_width = ov9282->cur_mode->width + ov9282->hblank_ctrl->val; + u64 ns = value * 1000 * frame_width / OV9282_STROBE_SPAN_FACTOR; + u32 us = ns / 1000; + u32 remainder = ns % 1000; + + if (remainder > 0) + us++; + return us; +} + +static int ov9282_set_ctrl_flash_duration(struct ov9282 *ov9282, int value) +{ + u32 val = ov9282_us_to_flash_duration(ov9282, value); 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 +818,35 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl) return ret; } +static int ov9282_try_ctrl(struct v4l2_ctrl *ctrl) +{ + struct ov9282 *ov9282 = + container_of(ctrl->handler, struct ov9282, ctrl_handler); + + if (ctrl->id == V4L2_CID_FLASH_DURATION) { + u32 fd = ov9282_us_to_flash_duration(ov9282, ctrl->val); + u32 us = ctrl->val; + u32 us0 = ov9282_flash_duration_to_us(ov9282, fd); + u32 us1 = ov9282_flash_duration_to_us(ov9282, (fd + 1)); + + if ((us1 - us) < (us - us0)) + ctrl->val = us1; + else + ctrl->val = us0; + + if (us != 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 = { .s_ctrl = ov9282_set_ctrl, + .try_ctrl = ov9282_try_ctrl, }; /**