From: Umang Jain <umang.jain@ideasonboard.com>
To: linux-media@vger.kernel.org
Cc: Alexander Shiyan <eagle.alexander923@gmail.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
open list <linux-kernel@vger.kernel.org>,
Umang Jain <umang.jain@ideasonboard.com>,
Tommaso Merciai <tomm.merciai@gmail.com>
Subject: [PATCH v3 6/6] media: imx335: Limit analogue gain value
Date: Thu, 21 Mar 2024 16:42:39 +0530 [thread overview]
Message-ID: <20240321111239.808735-7-umang.jain@ideasonboard.com> (raw)
In-Reply-To: <20240321111239.808735-1-umang.jain@ideasonboard.com>
The sensor gain (both analog and digital) are controlled by a
single gain value where:
- 0dB to 30dB correspond to analog gain
- 30.3dB to 72dB correspond to digital gain
(with 0.3dB step)
Hence, limit the analogue gain value to 100.
For digital gain, support can be added later if needed.
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Tommaso Merciai <tomm.merciai@gmail.com>
---
drivers/media/i2c/imx335.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/media/i2c/imx335.c b/drivers/media/i2c/imx335.c
index 10a09830dbd6..9eb8f70836fd 100644
--- a/drivers/media/i2c/imx335.c
+++ b/drivers/media/i2c/imx335.c
@@ -52,7 +52,7 @@
/* Analog gain control */
#define IMX335_REG_AGAIN CCI_REG8(0x30e8)
#define IMX335_AGAIN_MIN 0
-#define IMX335_AGAIN_MAX 240
+#define IMX335_AGAIN_MAX 100
#define IMX335_AGAIN_STEP 1
#define IMX335_AGAIN_DEFAULT 0
@@ -1175,6 +1175,14 @@ static int imx335_init_controls(struct imx335 *imx335)
IMX335_EXPOSURE_STEP,
IMX335_EXPOSURE_DEFAULT);
+ /*
+ * The sensor has an analog gain and a digital gain, both controlled
+ * through a single gain value, expressed in 0.3dB increments. Values
+ * from 0.0dB (0) to 30.0dB (100) apply analog gain only, higher values
+ * up to 72.0dB (240) add further digital gain. Limit the range to
+ * analog gain only, support for digital gain can be added separately
+ * if needed.
+ */
imx335->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
&imx335_ctrl_ops,
V4L2_CID_ANALOGUE_GAIN,
--
2.43.0
prev parent reply other threads:[~2024-03-21 11:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-21 11:12 [PATCH v3 0/6] media: imx335: 2/4 lane ops and improvements Umang Jain
2024-03-21 11:12 ` [PATCH v3 1/6] media: imx335: Support 2 or 4 lane operation modes Umang Jain
2024-03-21 11:12 ` [PATCH v3 2/6] media: imx335: Parse fwnode properties Umang Jain
2024-03-22 14:44 ` Tommaso Merciai
2024-03-21 11:12 ` [PATCH v3 3/6] media: imx335: Use V4L2 CCI for accessing sensor registers Umang Jain
2024-03-21 11:12 ` [PATCH v3 4/6] media: imx335: Use integer values for size registers Umang Jain
2024-03-21 11:12 ` [PATCH v3 5/6] media: imx335: Fix active area height discrepency Umang Jain
2024-03-21 11:12 ` Umang Jain [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240321111239.808735-7-umang.jain@ideasonboard.com \
--to=umang.jain@ideasonboard.com \
--cc=eagle.alexander923@gmail.com \
--cc=kieran.bingham@ideasonboard.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=sakari.ailus@linux.intel.com \
--cc=tomm.merciai@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).