[PATCH 2/3] drm/rockchip/dsi: enable the grf clk before writing grf registers
From: Chris Zhong
Date: Wed Mar 15 2017 - 04:43:29 EST
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@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
index f84f9ae..d8f24f2 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
@@ -291,6 +291,7 @@ 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;
@@ -979,6 +980,16 @@ 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.
+ */
+ ret = clk_prepare_enable(dsi->grf_clk);
+ if (ret) {
+ dev_err(dsi->dev, "Failed to enable grf_clk\n");
+ return;
+ }
+
if (pdata->grf_dsi0_mode_reg)
regmap_write(dsi->grf_regmap, pdata->grf_dsi0_mode_reg,
pdata->grf_dsi0_mode);
@@ -1003,6 +1014,8 @@ 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
@@ -1238,6 +1251,17 @@ static int dw_mipi_dsi_bind(struct device *dev, struct device *master,
dev_dbg(dev, "have not phy_cfg_clk\n");
}
+ dsi->grf_clk = devm_clk_get(dev, "grf");
+ if (IS_ERR(dsi->grf_clk)) {
+ ret = PTR_ERR(dsi->grf_clk);
+ if (ret != -ENOENT) {
+ dev_err(dev, "Unable to get grf_clk: %d\n", ret);
+ return ret;
+ }
+ dsi->grf_clk = NULL;
+ dev_dbg(dev, "have not grf_clk\n");
+ }
+
ret = clk_prepare_enable(dsi->pllref_clk);
if (ret) {
dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
--
2.6.3