drm/rockchip: dw-mipi-dsi: only request HS clock when required

Requesting the HS clock from the PHY before we initialize it causes an
invalid signal to be sent out since the input clock is not yet
configured.  The PHY databook suggests only asserting this signal when
performing HS transfers, so let's do that.

Change-Id: I7006f81d8c620dc84e84f99383c7b5414d6ac12d
Signed-off-by: xubilv <xbl@rock-chips.com>

Author: xubilv

drivers/gpu/drm/rockchip/dw-mipi-dsi.c

@@ -515,7 +515,6 @@ static int dw_mipi_dsi_phy_init(struct dw_mipi_dsi *dsi)
 	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
 				     PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
 
-
 	ret = readx_poll_timeout(readl, dsi->base + DSI_PHY_STATUS,
 				 val, val & LOCK, 1000, PHY_STATUS_TIMEOUT_US);
 	if (ret < 0) {
@@ -646,10 +645,13 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
 
 static void rockchip_set_transfer_mode(struct dw_mipi_dsi *dsi, int flags)
 {
-	if (flags & MIPI_DSI_MSG_USE_LPM)
+	if (flags & MIPI_DSI_MSG_USE_LPM) {
 		dsi_write(dsi, DSI_CMD_MODE_CFG, CMD_MODE_ALL_LP);
-	else
+		dsi_write(dsi, DSI_LPCLK_CTRL, 0);
+	} else {
 		dsi_write(dsi, DSI_CMD_MODE_CFG, 0);
+		dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
+	}
 }
 
 static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
@@ -752,7 +754,6 @@ static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
 		  | PHY_RSTZ | PHY_SHUTDOWNZ);
 	dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVIDSION(10) |
 		  TX_ESC_CLK_DIVIDSION(7));
-	dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
 }
 
 static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
@@ -1009,6 +1010,7 @@ static void rockchip_dsi_init(struct dw_mipi_dsi *dsi)
 
 static void rockchip_dsi_enable(struct dw_mipi_dsi *dsi)
 {
+	dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
 	dw_mipi_dsi_set_mode(dsi, DSI_VIDEO_MODE);
 	clk_disable_unprepare(dsi->pllref_clk);
 	clk_disable_unprepare(dsi->pclk);