[PATCH rtw-next v6 2/3] wifi: rtw88: rtw8822c: Convert DAC IQ calibration path to signed math

[Arsenii Pashchenko <ulijg308@gmail.com>]

Convert the temporary stack arrays 'iv' and 'qv' from u32 to s32.
Update all internal function signatures to accept s32 pointers and
handle signed values natively.

Use sign_extend32() combined with FIELD_GET() to properly interpret
the 10-bit hardware values as signed integers. This allows flattening
the complex nested unsigned boundary conditions in
rtw8822c_dac_iq_check() into a simple amplitude boundary check. Ensure
rtw8822c_dac_iq_offset() properly maps the signed average back to a
10-bit unsigned format expected by the hardware registers.

Signed-off-by: Arsenii Pashchenko <ulijg308@gmail.com>
---
 drivers/net/wireless/realtek/rtw88/rtw8822c.c | 135 ++++++------------
 1 file changed, 40 insertions(+), 95 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/rtw8822c.c b/drivers/net/wireless/realtek/rtw88/rtw8822c.c
index 137544649..a10e87d6e 100644
--- a/drivers/net/wireless/realtek/rtw88/rtw8822c.c
+++ b/drivers/net/wireless/realtek/rtw88/rtw8822c.c
@@ -153,49 +153,14 @@ static void rtw8822c_dac_restore_reg(struct rtw_dev *rtwdev,
 	}
 }
 
-static void rtw8822c_rf_minmax_cmp(struct rtw_dev *rtwdev, u32 value,
-				   u32 *min, u32 *max)
+static void __rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, s32 *v1, s32 *v2)
 {
-	if (value >= 0x200) {
-		if (*min >= 0x200) {
-			if (*min > value)
-				*min = value;
-		} else {
-			*min = value;
-		}
-		if (*max >= 0x200) {
-			if (*max < value)
-				*max = value;
-		}
-	} else {
-		if (*min < 0x200) {
-			if (*min > value)
-				*min = value;
-		}
-
-		if (*max  >= 0x200) {
-			*max = value;
-		} else {
-			if (*max < value)
-				*max = value;
-		}
-	}
-}
-
-static void __rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, u32 *v1, u32 *v2)
-{
-	if (*v1 >= 0x200 && *v2 >= 0x200) {
-		if (*v1 > *v2)
-			swap(*v1, *v2);
-	} else if (*v1 < 0x200 && *v2 < 0x200) {
-		if (*v1 > *v2)
-			swap(*v1, *v2);
-	} else if (*v1 < 0x200 && *v2 >= 0x200) {
+	if (*v1 > *v2)
 		swap(*v1, *v2);
-	}
+
 }
 
-static void rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, u32 *iv, u32 *qv)
+static void rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, s32 *iv, s32 *qv)
 {
 	u32 i, j;
 
@@ -207,30 +172,16 @@ static void rtw8822c_dac_iq_sort(struct rtw_dev *rtwdev, u32 *iv, u32 *qv)
 	}
 }
 
-static void rtw8822c_dac_iq_offset(struct rtw_dev *rtwdev, u32 *vec, u32 *val)
+static u32 rtw8822c_dac_iq_offset(struct rtw_dev *rtwdev, s32 *vec)
 {
-	u32 p, m, t, i;
+	s32 sum = 0;
 
-	m = 0;
-	p = 0;
-	for (i = 10; i < DACK_SN_8822C - 10; i++) {
-		if (vec[i] > 0x200)
-			m = (0x400 - vec[i]) + m;
-		else
-			p = vec[i] + p;
-	}
+	for (u32 i = 10; i < DACK_SN_8822C - 10; i++)
+		sum += vec[i];
 
-	if (p > m) {
-		t = p - m;
-		t = t / (DACK_SN_8822C - 20);
-	} else {
-		t = m - p;
-		t = t / (DACK_SN_8822C - 20);
-		if (t != 0x0)
-			t = 0x400 - t;
-	}
+	s32 avg = sum / (DACK_SN_8822C - 20);
 
-	*val = t;
+	return avg >= 0 ? (u32)avg : (u32)(0x400 + avg);
 }
 
 static u32 rtw8822c_get_path_write_addr(u8 path)
@@ -271,20 +222,18 @@ static u32 rtw8822c_get_path_read_addr(u8 path)
 	return base_addr;
 }
 
-static bool rtw8822c_dac_iq_check(struct rtw_dev *rtwdev, u32 value)
+static bool rtw8822c_dac_iq_check(struct rtw_dev *rtwdev, s32 value)
 {
-	bool ret = true;
 
-	if ((value >= 0x200 && (0x400 - value) > 0x64) ||
-	    (value < 0x200 && value > 0x64)) {
-		ret = false;
+	if (value > 100 || value < -100) {
 		rtw_dbg(rtwdev, RTW_DBG_RFK, "[DACK] Error overflow\n");
+		return false;
 	}
 
-	return ret;
+	return true;
 }
 
-static void rtw8822c_dac_cal_iq_sample(struct rtw_dev *rtwdev, u32 *iv, u32 *qv)
+static void rtw8822c_dac_cal_iq_sample(struct rtw_dev *rtwdev, s32 *iv, s32 *qv)
 {
 	u32 temp;
 	int i = 0, cnt = 0;
@@ -292,8 +241,8 @@ static void rtw8822c_dac_cal_iq_sample(struct rtw_dev *rtwdev, u32 *iv, u32 *qv)
 	while (i < DACK_SN_8822C && cnt < 10000) {
 		cnt++;
 		temp = rtw_read32(rtwdev, 0x2dbc);
-		iv[i] = FIELD_GET(RTW8822C_DAC_IV_MASK, temp);
-		qv[i] = FIELD_GET(RTW8822C_DAC_QV_MASK, temp);
+		iv[i] = FIELD_GET_SIGNED(RTW8822C_DAC_IV_MASK, temp);
+		qv[i] = FIELD_GET_SIGNED(RTW8822C_DAC_QV_MASK, temp);
 
 		if (rtw8822c_dac_iq_check(rtwdev, iv[i]) &&
 		    rtw8822c_dac_iq_check(rtwdev, qv[i]))
@@ -302,67 +251,63 @@ static void rtw8822c_dac_cal_iq_sample(struct rtw_dev *rtwdev, u32 *iv, u32 *qv)
 }
 
 static void rtw8822c_dac_cal_iq_search(struct rtw_dev *rtwdev,
-				       u32 *iv, u32 *qv,
+				       s32 *iv, s32 *qv,
 				       u32 *i_value, u32 *q_value)
 {
-	u32 i_max = 0, q_max = 0, i_min = 0, q_min = 0;
+	s32 i_max = 0, q_max = 0, i_min = 0, q_min = 0;
 	u32 i_delta, q_delta;
 	u32 temp;
-	int i, cnt = 0;
+	u32 i, cnt = 0;
 
 	do {
 		i_min = iv[0];
 		i_max = iv[0];
 		q_min = qv[0];
 		q_max = qv[0];
-		for (i = 0; i < DACK_SN_8822C; i++) {
-			rtw8822c_rf_minmax_cmp(rtwdev, iv[i], &i_min, &i_max);
-			rtw8822c_rf_minmax_cmp(rtwdev, qv[i], &q_min, &q_max);
+		for (i = 1; i < DACK_SN_8822C; i++) {
+			if (iv[i] < i_min)
+				i_min = iv[i];
+			if (iv[i] > i_max)
+				i_max = iv[i];
+			if (qv[i] < q_min)
+				q_min = qv[i];
+			if (qv[i] > q_max)
+				q_max = qv[i];
 		}
 
-		if (i_max < 0x200 && i_min < 0x200)
-			i_delta = i_max - i_min;
-		else if (i_max >= 0x200 && i_min >= 0x200)
-			i_delta = i_max - i_min;
-		else
-			i_delta = i_max + (0x400 - i_min);
+		i_delta = i_max - i_min;
+		q_delta = q_max - q_min;
 
-		if (q_max < 0x200 && q_min < 0x200)
-			q_delta = q_max - q_min;
-		else if (q_max >= 0x200 && q_min >= 0x200)
-			q_delta = q_max - q_min;
-		else
-			q_delta = q_max + (0x400 - q_min);
 
 		rtw_dbg(rtwdev, RTW_DBG_RFK,
-			"[DACK] i: min=0x%08x, max=0x%08x, delta=0x%08x\n",
+			"[DACK] i: min=%d, max=%d, delta=%d\n",
 			i_min, i_max, i_delta);
 		rtw_dbg(rtwdev, RTW_DBG_RFK,
-			"[DACK] q: min=0x%08x, max=0x%08x, delta=0x%08x\n",
+			"[DACK] q: min=%d, max=%d, delta=%d",
 			q_min, q_max, q_delta);
 
 		rtw8822c_dac_iq_sort(rtwdev, iv, qv);
 
 		if (i_delta > 5 || q_delta > 5) {
 			temp = rtw_read32(rtwdev, 0x2dbc);
-			iv[0] = FIELD_GET(RTW8822C_DAC_IV_MASK, temp);
-			qv[0] = FIELD_GET(RTW8822C_DAC_QV_MASK, temp);
+			iv[0] = FIELD_GET_SIGNED(RTW8822C_DAC_IV_MASK, temp);
+			qv[0] = FIELD_GET_SIGNED(RTW8822C_DAC_QV_MASK, temp);
 			temp = rtw_read32(rtwdev, 0x2dbc);
-			iv[DACK_SN_8822C - 1] = FIELD_GET(RTW8822C_DAC_IV_MASK, temp);
-			qv[DACK_SN_8822C - 1] = FIELD_GET(RTW8822C_DAC_QV_MASK, temp);
+			iv[DACK_SN_8822C - 1] = FIELD_GET_SIGNED(RTW8822C_DAC_IV_MASK, temp);
+			qv[DACK_SN_8822C - 1] = FIELD_GET_SIGNED(RTW8822C_DAC_QV_MASK, temp);
 		} else {
 			break;
 		}
 	} while (cnt++ < 100);
 
-	rtw8822c_dac_iq_offset(rtwdev, iv, i_value);
-	rtw8822c_dac_iq_offset(rtwdev, qv, q_value);
+	*i_value = rtw8822c_dac_iq_offset(rtwdev, iv);
+	*q_value = rtw8822c_dac_iq_offset(rtwdev, qv);
 }
 
 static void rtw8822c_dac_cal_rf_mode(struct rtw_dev *rtwdev,
 				     u32 *i_value, u32 *q_value)
 {
-	u32 iv[DACK_SN_8822C], qv[DACK_SN_8822C];
+	s32 iv[DACK_SN_8822C], qv[DACK_SN_8822C];
 	u32 rf_a, rf_b;
 
 	rf_a = rtw_read_rf(rtwdev, RF_PATH_A, 0x0, RFREG_MASK);
-- 
2.55.0