From: Bingbu Cao <bingbu.cao@intel.com>
To: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com
Cc: senozhatsky@chromium.org, tfiga@chromium.org,
bingbu.cao@intel.com, bingbu.cao@linux.intel.com,
tian.shu.qiu@intel.com
Subject: [PATCH] media: ov2740: use group write for digital gain
Date: Mon, 5 Jul 2021 14:50:59 +0800 [thread overview]
Message-ID: <1625467859-27486-1-git-send-email-bingbu.cao@intel.com> (raw)
As the RGB digital gains of ov2740 were not applied as group, some
artifacts were observed in low light environment, use group write for
digital gain can make the RGB digital can be guaranteed to applied
together at frame boundary.
Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
---
drivers/media/i2c/ov2740.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
index 599369a3d192..934c9d65cb09 100644
--- a/drivers/media/i2c/ov2740.c
+++ b/drivers/media/i2c/ov2740.c
@@ -51,7 +51,7 @@
#define OV2740_REG_MWB_R_GAIN 0x500a
#define OV2740_REG_MWB_G_GAIN 0x500c
#define OV2740_REG_MWB_B_GAIN 0x500e
-#define OV2740_DGTL_GAIN_MIN 0
+#define OV2740_DGTL_GAIN_MIN 1024
#define OV2740_DGTL_GAIN_MAX 4095
#define OV2740_DGTL_GAIN_STEP 1
#define OV2740_DGTL_GAIN_DEFAULT 1024
@@ -61,6 +61,12 @@
#define OV2740_TEST_PATTERN_ENABLE BIT(7)
#define OV2740_TEST_PATTERN_BAR_SHIFT 2
+/* Group Access */
+#define OV2740_REG_GROUP_ACCESS 0x3208
+#define OV2740_GROUP_HOLD_START 0x0
+#define OV2740_GROUP_HOLD_END 0x10
+#define OV2740_GROUP_HOLD_LAUNCH 0xa0
+
/* ISP CTRL00 */
#define OV2740_REG_ISP_CTRL00 0x5000
/* ISP CTRL01 */
@@ -438,6 +444,11 @@ static int ov2740_update_digital_gain(struct ov2740 *ov2740, u32 d_gain)
{
int ret = 0;
+ ret = ov2740_write_reg(ov2740, OV2740_REG_GROUP_ACCESS, 1,
+ OV2740_GROUP_HOLD_START);
+ if (ret)
+ return ret;
+
ret = ov2740_write_reg(ov2740, OV2740_REG_MWB_R_GAIN, 2, d_gain);
if (ret)
return ret;
@@ -446,7 +457,18 @@ static int ov2740_update_digital_gain(struct ov2740 *ov2740, u32 d_gain)
if (ret)
return ret;
- return ov2740_write_reg(ov2740, OV2740_REG_MWB_B_GAIN, 2, d_gain);
+ ret = ov2740_write_reg(ov2740, OV2740_REG_MWB_B_GAIN, 2, d_gain);
+ if (ret)
+ return ret;
+
+ ret = ov2740_write_reg(ov2740, OV2740_REG_GROUP_ACCESS, 1,
+ OV2740_GROUP_HOLD_END);
+ if (ret)
+ return ret;
+
+ ret = ov2740_write_reg(ov2740, OV2740_REG_GROUP_ACCESS, 1,
+ OV2740_GROUP_HOLD_LAUNCH);
+ return ret;
}
static int ov2740_test_pattern(struct ov2740 *ov2740, u32 pattern)
--
2.7.4
reply other threads:[~2021-07-05 6:50 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=1625467859-27486-1-git-send-email-bingbu.cao@intel.com \
--to=bingbu.cao@intel.com \
--cc=bingbu.cao@linux.intel.com \
--cc=linux-media@vger.kernel.org \
--cc=sakari.ailus@linux.intel.com \
--cc=senozhatsky@chromium.org \
--cc=tfiga@chromium.org \
--cc=tian.shu.qiu@intel.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).