[PATCH] drm/bridge/synopsys: dsi: Wait for all active lanes to reach stop

[Matt Redfearn]

The Synopsys manual states that software should wait for all active
lanes to reach stop state (User manual section 3.1.5). Currently the
driver only waits for / checks that the clock lane is in stop state. Fix
this by waiting for the mask of PHY STATUS bits corresponding to the
active lanes to be set.

Signed-off-by: Matt Redfearn <matt.redfearn at thinci.com>

---

 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index bd15c21a177..38e88071363 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -189,6 +189,10 @@
 #define DSI_PHY_TX_TRIGGERS		0xac
 
 #define DSI_PHY_STATUS			0xb0
+#define PHY_STOP_STATE_LANE_3		BIT(11)
+#define PHY_STOP_STATE_LANE_2		BIT(9)
+#define PHY_STOP_STATE_LANE_1		BIT(7)
+#define PHY_STOP_STATE_LANE_0		BIT(4)
 #define PHY_STOP_STATE_CLK_LANE		BIT(2)
 #define PHY_LOCK			BIT(0)
 
@@ -752,7 +756,7 @@ static void dw_mipi_dsi_dphy_init(struct dw_mipi_dsi *dsi)
 
 static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
 {
-	u32 val;
+	u32 val, mask;
 	int ret;
 
 	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
@@ -763,11 +767,16 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
 	if (ret)
 		DRM_DEBUG_DRIVER("failed to wait phy lock state\n");
 
+	mask = PHY_STOP_STATE_CLK_LANE | PHY_STOP_STATE_LANE_0;
+	mask |= (dsi->lanes >= 2) ? PHY_STOP_STATE_LANE_1 : 0;
+	mask |= (dsi->lanes >= 3) ? PHY_STOP_STATE_LANE_2 : 0;
+	mask |= (dsi->lanes == 4) ? PHY_STOP_STATE_LANE_3 : 0;
+
 	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
-				 val, val & PHY_STOP_STATE_CLK_LANE, 1000,
+				 val, (val & mask) == mask, 1000,
 				 PHY_STATUS_TIMEOUT_US);
 	if (ret)
-		DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n");
+		DRM_DEBUG_DRIVER("failed to wait phy stop state\n");
 }
 
 static void dw_mipi_dsi_clear_err(struct dw_mipi_dsi *dsi)
-- 
2.17.1