[PATCH v1 1/1] drm/bridge: anx7625: Tune K value for IVO panel

From: Xin Ji
Date: Thu Aug 05 2021 - 03:31:07 EST


IVO panel require less input video clock variation than video clock
variation in DP CTS spec.

This patch decreases the K value of ANX7625 which will shrink eDP Tx
video clock variation to meet IVO panel's requirement.

Signed-off-by: Xin Ji <xji@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/analogix/anx7625.c | 17 ++++++++++++++---
drivers/gpu/drm/bridge/analogix/anx7625.h | 4 +++-
2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index a3d82377066b..ceed1c7f3f28 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -384,6 +384,18 @@ static int anx7625_odfc_config(struct anx7625_data *ctx,
return ret;
}

+static int anx7625_set_k_value(struct anx7625_data *ctx)
+{
+ struct edid *edid = (struct edid *)ctx->slimport_edid_p.edid_raw_data;
+
+ if (edid->mfg_id[0] == IVO_MID0 && edid->mfg_id[1] == IVO_MID1)
+ return anx7625_reg_write(ctx, ctx->i2c.rx_p1_client,
+ MIPI_DIGITAL_ADJ_1, 0x3B);
+
+ return anx7625_reg_write(ctx, ctx->i2c.rx_p1_client,
+ MIPI_DIGITAL_ADJ_1, 0x3D);
+}
+
static int anx7625_dsi_video_timing_config(struct anx7625_data *ctx)
{
struct device *dev = &ctx->client->dev;
@@ -470,9 +482,8 @@ static int anx7625_dsi_video_timing_config(struct anx7625_data *ctx)
MIPI_PLL_N_NUM_15_8, (n >> 8) & 0xff);
ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p1_client, MIPI_PLL_N_NUM_7_0,
(n & 0xff));
- /* Diff */
- ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p1_client,
- MIPI_DIGITAL_ADJ_1, 0x3D);
+ /* Diff and K value */
+ anx7625_set_k_value(ctx);

ret |= anx7625_odfc_config(ctx, post_divider - 1);

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index 034c3840028f..6dcf64c703f9 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -210,7 +210,9 @@
#define MIPI_VIDEO_STABLE_CNT 0x0A

#define MIPI_LANE_CTRL_10 0x0F
-#define MIPI_DIGITAL_ADJ_1 0x1B
+#define MIPI_DIGITAL_ADJ_1 0x1B
+#define IVO_MID0 0x26
+#define IVO_MID1 0xCF

#define MIPI_PLL_M_NUM_23_16 0x1E
#define MIPI_PLL_M_NUM_15_8 0x1F
--
2.25.1