Merge tag 'mediatek-drm-next-6.14' of https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux into drm-next

Mediatek DRM Next for Linux 6.14

1. dp: Add sdp path reset
2. dp: Support flexible length of DP calibration data

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250104125538.111118-1-chunkuang.hu@kernel.org

Author: airlied

drivers/gpu/drm/mediatek/mtk_dp.c

@@ -1135,6 +1135,18 @@ static void mtk_dp_digital_sw_reset(struct mtk_dp *mtk_dp)
 			   0, DP_TX_TRANSMITTER_4P_RESET_SW_DP_TRANS_P0);
 }
 
+static void mtk_dp_sdp_path_reset(struct mtk_dp *mtk_dp)
+{
+	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3004,
+			   SDP_RESET_SW_DP_ENC0_P0,
+			   SDP_RESET_SW_DP_ENC0_P0);
+
+	/* Wait for sdp path reset to complete */
+	usleep_range(1000, 5000);
+	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3004,
+			   0, SDP_RESET_SW_DP_ENC0_P0);
+}
+
 static void mtk_dp_set_lanes(struct mtk_dp *mtk_dp, int lanes)
 {
 	mtk_dp_update_bits(mtk_dp, MTK_DP_TRANS_P0_35F0,
@@ -1165,17 +1177,25 @@ static void mtk_dp_get_calibration_data(struct mtk_dp *mtk_dp)
 	buf = (u32 *)nvmem_cell_read(cell, &len);
 	nvmem_cell_put(cell);
 
-	if (IS_ERR(buf) || ((len / sizeof(u32)) != 4)) {
+	if (IS_ERR(buf)) {
 		dev_warn(dev, "Failed to read nvmem_cell_read\n");
-
-		if (!IS_ERR(buf))
-			kfree(buf);
-
 		goto use_default_val;
 	}
 
+	/* The cell length is in bytes. Convert it to be compatible with u32 buffer. */
+	len /= sizeof(u32);
+
 	for (i = 0; i < MTK_DP_CAL_MAX; i++) {
 		fmt = &mtk_dp->data->efuse_fmt[i];
+
+		if (fmt->idx >= len) {
+			dev_warn(mtk_dp->dev,
+				 "Out-of-bound efuse data access, fmt idx = %d, buf len = %zu\n",
+				 fmt->idx, len);
+			kfree(buf);
+			goto use_default_val;
+		}
+
 		cal_data[i] = (buf[fmt->idx] >> fmt->shift) & fmt->mask;
 
 		if (cal_data[i] < fmt->min_val || cal_data[i] > fmt->max_val) {
@@ -2397,6 +2417,9 @@ static void mtk_dp_bridge_atomic_disable(struct drm_bridge *bridge,
 			   DP_PWR_STATE_BANDGAP_TPLL,
 			   DP_PWR_STATE_MASK);
 
+	/* SDP path reset sw*/
+	mtk_dp_sdp_path_reset(mtk_dp);
+
 	/* Ensure the sink is muted */
 	msleep(20);
 }

drivers/gpu/drm/mediatek/mtk_dp_reg.h

@@ -86,6 +86,7 @@
 #define MTK_DP_ENC0_P0_3004			0x3004
 #define VIDEO_M_CODE_SEL_DP_ENC0_P0_MASK		BIT(8)
 #define DP_TX_ENCODER_4P_RESET_SW_DP_ENC0_P0		BIT(9)
+#define SDP_RESET_SW_DP_ENC0_P0				BIT(13)
 #define MTK_DP_ENC0_P0_3010			0x3010
 #define HTOTAL_SW_DP_ENC0_P0_MASK			GENMASK(15, 0)
 #define MTK_DP_ENC0_P0_3014			0x3014