[PATCH 6/7] drm/mediatek: dpi: add support for dpi clock

[Fabien Parent <fparent@baylibre.com>]

MT8365 requires an additional clock for DPI. Add support for that
additional clock.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index e61cd67b978f..7872db60840e 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -72,6 +72,7 @@ struct mtk_dpi {
 	struct device *dev;
 	struct clk *engine_clk;
 	struct clk *pixel_clk;
+	struct clk *dpi_clk;
 	struct clk *tvd_clk;
 	int irq;
 	struct drm_display_mode mode;
@@ -412,6 +413,7 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 	mtk_dpi_disable(dpi);
 	clk_disable_unprepare(dpi->pixel_clk);
 	clk_disable_unprepare(dpi->engine_clk);
+	clk_disable_unprepare(dpi->dpi_clk);
 }
 
 static int mtk_dpi_power_on(struct mtk_dpi *dpi)
@@ -421,10 +423,16 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 	if (++dpi->refcount != 1)
 		return 0;
 
+	ret = clk_prepare_enable(dpi->dpi_clk);
+	if (ret) {
+		dev_err(dpi->dev, "failed to enable dpi clock: %d\n", ret);
+		goto err_refcount;
+	}
+
 	ret = clk_prepare_enable(dpi->engine_clk);
 	if (ret) {
 		dev_err(dpi->dev, "Failed to enable engine clock: %d\n", ret);
-		goto err_refcount;
+		goto err_engine;
 	}
 
 	ret = clk_prepare_enable(dpi->pixel_clk);
@@ -441,6 +449,8 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 
 err_pixel:
 	clk_disable_unprepare(dpi->engine_clk);
+err_engine:
+	clk_disable_unprepare(dpi->dpi_clk);
 err_refcount:
 	dpi->refcount--;
 	return ret;
@@ -893,6 +903,12 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	dpi->dpi_clk = devm_clk_get_optional(dev, "dpi");
+	if (IS_ERR(dpi->dpi_clk)) {
+		return dev_err_probe(dev, ret, "Failed to get dpi clock: %pe\n",
+				     dpi->dpi_clk);
+	}
+
 	dpi->irq = platform_get_irq(pdev, 0);
 	if (dpi->irq <= 0)
 		return -EINVAL;
-- 
2.36.1