[PATCH v3] media: i2c: ov9282: Add test pattern control

[Xiaolei Wang <xiaolei.wang@windriver.com>]

Add V4L2_CID_TEST_PATTERN control with bar and solid white patterns.
Since the OV9282 is a monochrome sensor, white is more useful than
black for solid pattern testing.

Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
---

Changes in v3:
 - Move OV9282_TEST_PATTERN_SOLID_DEFAULT out of the ternary operator
   since it is unconditional (Sakari)
 Link to v2: https://patchwork.linuxtv.org/project/linux-media/patch/20260318051618.471375-1-xiaolei.wang@windriver.com/

Changes in v2:
 - Rename to "Bar" / "Solid White" since OV9282 is a monochrome
   sensor (Dave)
 - Use cci_write instead of cci_update_bits (Dave)
 - Default solid pattern to white (Dave)
 Link to v1: https://patchwork.linuxtv.org/project/linux-media/patch/20260316090558.1537823-1-xiaolei.wang@windriver.com/

 drivers/media/i2c/ov9282.c | 61 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 60 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
index 2167fb73ea41..b2fcee5c0be1 100644
--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -104,6 +104,17 @@
 #define OV9282_REG_STROBE_FRAME_SPAN		CCI_REG32(0x3925)
 #define OV9282_STROBE_FRAME_SPAN_DEFAULT	0x0000001a
 
+/* Test Pattern registers */
+#define OV9282_REG_TEST_PATTERN_BAR	CCI_REG8(0x5e00)
+#define OV9282_TEST_PATTERN_BAR_EN	BIT(7)
+#define OV9282_REG_TEST_PATTERN_SOLID	CCI_REG8(0x4320)
+#define OV9282_TEST_PATTERN_SOLID_EN	BIT(1)
+#define OV9282_TEST_PATTERN_SOLID_DEFAULT	0x80
+#define OV9282_REG_SOLID_P1		CCI_REG16(0x4322)
+#define OV9282_REG_SOLID_P2		CCI_REG16(0x4324)
+#define OV9282_REG_SOLID_P3		CCI_REG16(0x4328)
+#define OV9282_REG_SOLID_P4		CCI_REG16(0x4326)
+
 /* Input clock rate */
 #define OV9282_INCLK_RATE	24000000
 
@@ -462,6 +473,18 @@ static const struct ov9282_mode supported_modes[] = {
 	},
 };
 
+enum {
+	OV9282_TEST_PATTERN_DISABLED,
+	OV9282_TEST_PATTERN_BAR,
+	OV9282_TEST_PATTERN_SOLID_WHITE,
+};
+
+static const char * const ov9282_test_pattern_menu[] = {
+	"Disabled",
+	"Bar",
+	"Solid White",
+};
+
 /**
  * to_ov9282() - ov9282 V4L2 sub-device to ov9282 device.
  * @subdev: pointer to ov9282 V4L2 sub-device
@@ -586,6 +609,32 @@ static u32 ov9282_flash_duration_to_us(struct ov9282 *ov9282, u32 value)
 	return DIV_ROUND_UP(value * frame_width, OV9282_STROBE_SPAN_FACTOR);
 }
 
+static int ov9282_set_ctrl_test_pattern(struct ov9282 *ov9282, int pattern)
+{
+	int ret;
+
+	ret = cci_write(ov9282->regmap, OV9282_REG_TEST_PATTERN_BAR,
+			pattern == OV9282_TEST_PATTERN_BAR ?
+			OV9282_TEST_PATTERN_BAR_EN : 0, NULL);
+	if (ret)
+		return ret;
+
+	if (pattern == OV9282_TEST_PATTERN_SOLID_WHITE) {
+		/* Set all four pixel values to 0x3ff (white) */
+		cci_write(ov9282->regmap, OV9282_REG_SOLID_P1, 0x3ff, &ret);
+		cci_write(ov9282->regmap, OV9282_REG_SOLID_P2, 0x3ff, &ret);
+		cci_write(ov9282->regmap, OV9282_REG_SOLID_P3, 0x3ff, &ret);
+		cci_write(ov9282->regmap, OV9282_REG_SOLID_P4, 0x3ff, &ret);
+		if (ret)
+			return ret;
+	}
+
+	return cci_write(ov9282->regmap, OV9282_REG_TEST_PATTERN_SOLID,
+			 OV9282_TEST_PATTERN_SOLID_DEFAULT |
+			 (pattern == OV9282_TEST_PATTERN_SOLID_WHITE ?
+			 OV9282_TEST_PATTERN_SOLID_EN : 0), NULL);
+}
+
 /**
  * ov9282_set_ctrl() - Set subdevice control
  * @ctrl: pointer to v4l2_ctrl structure
@@ -662,6 +711,11 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl)
 	case V4L2_CID_FLASH_DURATION:
 		ret = cci_write(ov9282->regmap, OV9282_REG_STROBE_FRAME_SPAN, ctrl->val, NULL);
 		break;
+
+	case V4L2_CID_TEST_PATTERN:
+		ret = ov9282_set_ctrl_test_pattern(ov9282, ctrl->val);
+		break;
+
 	default:
 		dev_err(ov9282->dev, "Invalid control %d", ctrl->id);
 		ret = -EINVAL;
@@ -1242,7 +1296,7 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
 	u32 lpfr;
 	int ret;
 
-	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 12);
+	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 13);
 	if (ret)
 		return ret;
 
@@ -1314,6 +1368,11 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
 				  V4L2_CID_FLASH_DURATION, 0, exposure_us, 1,
 				  OV9282_STROBE_FRAME_SPAN_DEFAULT);
 
+	v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &ov9282_ctrl_ops,
+				     V4L2_CID_TEST_PATTERN,
+				     ARRAY_SIZE(ov9282_test_pattern_menu) - 1,
+				     0, 0, ov9282_test_pattern_menu);
+
 	ret = v4l2_fwnode_device_parse(ov9282->dev, &props);
 	if (!ret) {
 		/* Failure sets ctrl_hdlr->error, which we check afterwards anyway */
-- 
2.43.0