drm/rockchip/dsi: enable the grf clk before writing grf registers

For RK3399, the grf clk should be enabled before writing grf registers,
otherwise the register value can not be changed.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1490147691-4489-4-git-send-email-zyw@rock-chips.com

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
index ccfb86a1c50118952084f7b3a3638aab14fb4bf4..6a017be99557a4a7bdd0d9748d848f97a3cda25b 100644 (file)
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
@@ -252,6 +252,7 @@
 #define THS_ZERO_PROGRAM_EN    BIT(6)
 
 #define DW_MIPI_NEEDS_PHY_CFG_CLK      BIT(0)
+#define DW_MIPI_NEEDS_GRF_CLK          BIT(1)
 
 enum {
        BANDGAP_97_07,
@@ -294,6 +295,7 @@ struct dw_mipi_dsi {
        struct regmap *grf_regmap;
        void __iomem *base;
 
+       struct clk *grf_clk;
        struct clk *pllref_clk;
        struct clk *pclk;
        struct clk *phy_cfg_clk;
@@ -982,6 +984,17 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder)
        dw_mipi_dsi_dphy_interface_config(dsi);
        dw_mipi_dsi_clear_err(dsi);
 
+       /*
+        * For the RK3399, the clk of grf must be enabled before writing grf
+        * register. And for RK3288 or other soc, this grf_clk must be NULL,
+        * the clk_prepare_enable return true directly.
+        */
+       ret = clk_prepare_enable(dsi->grf_clk);
+       if (ret) {
+               dev_err(dsi->dev, "Failed to enable grf_clk: %d\n", ret);
+               return;
+       }
+
        if (pdata->grf_dsi0_mode_reg)
                regmap_write(dsi->grf_regmap, pdata->grf_dsi0_mode_reg,
                             pdata->grf_dsi0_mode);
@@ -1006,6 +1019,8 @@ static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder)
        regmap_write(dsi->grf_regmap, pdata->grf_switch_reg, val);
        dev_dbg(dsi->dev, "vop %s output to dsi0\n", (mux) ? "LIT" : "BIG");
        dsi->dpms_mode = DRM_MODE_DPMS_ON;
+
+       clk_disable_unprepare(dsi->grf_clk);
 }
 
 static int
@@ -1139,7 +1154,7 @@ static struct dw_mipi_dsi_plat_data rk3399_mipi_dsi_drv_data = {
        .grf_switch_reg = RK3399_GRF_SOC_CON19,
        .grf_dsi0_mode = RK3399_GRF_DSI_MODE,
        .grf_dsi0_mode_reg = RK3399_GRF_SOC_CON22,
-       .flags = DW_MIPI_NEEDS_PHY_CFG_CLK,
+       .flags = DW_MIPI_NEEDS_PHY_CFG_CLK | DW_MIPI_NEEDS_GRF_CLK,
        .max_data_lanes = 4,
 };
 
@@ -1240,6 +1255,15 @@ static int dw_mipi_dsi_bind(struct device *dev, struct device *master,
                }
        }
 
+       if (pdata->flags & DW_MIPI_NEEDS_GRF_CLK) {
+               dsi->grf_clk = devm_clk_get(dev, "grf");
+               if (IS_ERR(dsi->grf_clk)) {
+                       ret = PTR_ERR(dsi->grf_clk);
+                       dev_err(dev, "Unable to get grf_clk: %d\n", ret);
+                       return ret;
+               }
+       }
+
        ret = clk_prepare_enable(dsi->pllref_clk);
        if (ret) {
                dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);