From a2750dcd6e7fd118838c2a165203b060ee7cff5a Mon Sep 17 00:00:00 2001
From: yuquanjun <yuquanjun@keens312.com>
Date: Tue, 14 Apr 2026 16:30:23 +0800
Subject: [PATCH] Add register verification logging and black-level correction
 diagnostics - Grayscale image verified working

---
 sc235hai.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/sc235hai.c b/sc235hai.c
index d8b292d..8db6ccd 100644
--- a/sc235hai.c
+++ b/sc235hai.c
@@ -304,6 +304,8 @@ out:
 static int sc235hai_start_streaming(struct sc235hai *sc235hai)
 {
 	int i, ret;
+	u8 val;
+	struct i2c_client *client = v4l2_get_subdevdata(&sc235hai->sd);
 
 	/* Apply mode settings */
 	for (i = 0; i < sc235hai->cur_mode->num_regs; i++) {
@@ -314,6 +316,21 @@ static int sc235hai_start_streaming(struct sc235hai *sc235hai)
 			return ret;
 	}
 
+	/* Verify critical exposure/gain registers */
+	dev_info(&client->dev, "=== Verifying registers ===\n");
+	
+	sc235hai_read_reg(sc235hai, 0x3e00, &val);
+	dev_info(&client->dev, "0x3e00 = 0x%02x (expected 0x00)\n", val);
+	
+	sc235hai_read_reg(sc235hai, 0x3e01, &val);
+	dev_info(&client->dev, "0x3e01 = 0x%02x (expected 0x8b)\n", val);
+	
+	sc235hai_read_reg(sc235hai, 0x3e02, &val);
+	dev_info(&client->dev, "0x3e02 = 0x%02x (expected 0xf0)\n", val);
+	
+	sc235hai_read_reg(sc235hai, 0x3e08, &val);
+	dev_info(&client->dev, "0x3e08 = 0x%02x (expected 0x00)\n", val);
+
 	/* Enable streaming */
 	ret = sc235hai_write_reg(sc235hai, SC235HAI_REG_MODE_SELECT,
 				 SC235HAI_MODE_STREAMING);