From 3efb087f485e02291124f64267e6d92e48135f1f Mon Sep 17 00:00:00 2001
From: Hu Kejun <william.hu@rock-chips.com>
Date: Wed, 30 Apr 2025 17:54:31 +0800
Subject: [PATCH] media: i2c: dw9800v: fix motor pos is wrong after change max
 logicalpos

Signed-off-by: Hu Kejun <william.hu@rock-chips.com>
Change-Id: I1136ffab716af60c461b03ad5bd71ed811b1fb0b
---
 drivers/media/i2c/dw9800v.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/media/i2c/dw9800v.c b/drivers/media/i2c/dw9800v.c
index 1a29f4c981be..b01940a62bfc 100644
--- a/drivers/media/i2c/dw9800v.c
+++ b/drivers/media/i2c/dw9800v.c
@@ -64,7 +64,6 @@ struct dw9800v_device {
 	unsigned short current_lens_pos;
 	unsigned int start_current;
 	unsigned int rated_current;
-	unsigned int step;
 	unsigned int step_mode;
 	unsigned int vcm_movefull_t;
 	unsigned int t_src;
@@ -277,20 +276,22 @@ static int dw9800v_get_pos(struct dw9800v_device *dev_vcm,
 {
 	struct i2c_client *client = dev_vcm->client;
 	int ret;
-	unsigned int dac, abs_step;
-
+	unsigned int dac, abs_step, range;
 
+	range = dev_vcm->rated_current - dev_vcm->start_current;
 	ret = dw9800v_read_reg(client, 0x03, 2, &dac);
 	if (ret != 0)
 		goto err;
 
-	if (dac <= dev_vcm->start_current)
+	if (dac <= dev_vcm->start_current) {
 		abs_step = dev_vcm->max_logicalpos;
-	else if ((dac > dev_vcm->start_current) &&
-		 (dac <= dev_vcm->rated_current))
-		abs_step = (dev_vcm->rated_current - dac) / dev_vcm->step;
-	else
+	} else if ((dac > dev_vcm->start_current) &&
+		   (dac <= dev_vcm->rated_current)) {
+		abs_step = (dac - dev_vcm->start_current) * dev_vcm->max_logicalpos / range;
+		abs_step = dev_vcm->max_logicalpos - abs_step;
+	} else {
 		abs_step = 0;
+	}
 
 	*cur_pos = abs_step;
 	v4l2_dbg(1, debug, &dev_vcm->sd, "%s: get position %d, dac %d\n",
@@ -308,14 +309,16 @@ static int dw9800v_set_pos(struct dw9800v_device *dev_vcm,
 {
 	int ret;
 	unsigned int position = 0;
+	unsigned int range;
 	struct i2c_client *client = dev_vcm->client;
 	u32 is_busy, i;
 
+	range = dev_vcm->rated_current - dev_vcm->start_current;
 	if (dest_pos >= dev_vcm->max_logicalpos)
 		position = dev_vcm->start_current;
 	else
 		position = dev_vcm->start_current +
-			   (dev_vcm->step * (dev_vcm->max_logicalpos - dest_pos));
+			   (range * (dev_vcm->max_logicalpos - dest_pos) / dev_vcm->max_logicalpos);
 
 	if (position > DW9800V_MAX_REG)
 		position = DW9800V_MAX_REG;
@@ -507,16 +510,12 @@ static const struct v4l2_subdev_internal_ops dw9800v_int_ops = {
 static void dw9800v_update_vcm_cfg(struct dw9800v_device *dev_vcm)
 {
 	struct i2c_client *client = dev_vcm->client;
-	int cur_dist;
 
 	if (dev_vcm->max_ma == 0) {
 		dev_err(&client->dev, "max current is zero");
 		return;
 	}
 
-	cur_dist = dev_vcm->vcm_cfg.rated_ma - dev_vcm->vcm_cfg.start_ma;
-	cur_dist = cur_dist * DW9800V_MAX_REG / dev_vcm->max_ma;
-	dev_vcm->step = (cur_dist + (dev_vcm->max_logicalpos - 1)) / dev_vcm->max_logicalpos;
 	dev_vcm->start_current = dev_vcm->vcm_cfg.start_ma *
 				 DW9800V_MAX_REG / dev_vcm->max_ma;
 	dev_vcm->rated_current = dev_vcm->vcm_cfg.rated_ma *