Thread (9 messages) 9 messages, 2 authors, 2021-05-26
STALE1831d
Revisions (5)
  1. v2 [diff vs current]
  2. v3 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current
  5. v5 [diff vs current]

[v4,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

From: Rex-BC Chen <hidden>
Date: 2021-05-25 12:15:06
Also in: linux-devicetree, linux-mediatek, lkml
Subsystem: drm drivers, drm drivers for mediatek, the rest · Maintainers: David Airlie, Simona Vetter, Chun-Kuang Hu, Philipp Zabel, Linus Torvalds

DPI can sample on falling, rising or both edge.
When DPI sample the data both rising and falling edge.
It can reduce half data io pins.
Use num_output_fmts to determine whether it is dual edge mode.

Signed-off-by: Jitao Shi <redacted>
Signed-off-by: Rex-BC Chen <redacted>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index bea91c81626e..d3b883c97aaf 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -83,6 +83,7 @@ struct mtk_dpi {
 	struct pinctrl *pinctrl;
 	struct pinctrl_state *pins_gpio;
 	struct pinctrl_state *pins_dpi;
+	bool ddr_edge_sel;
 	int refcount;
 };
 
@@ -122,6 +123,8 @@ struct mtk_dpi_conf {
 	u32 reg_h_fre_con;
 	u32 max_clock_khz;
 	bool edge_sel_en;
+	const u32 *output_fmts;
+	u32 num_output_fmts;
 };
 
 static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -381,6 +384,16 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
 	}
 }
 
+static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
+{
+	if (dpi->conf->num_output_fmts > 1) {
+		mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
+			     DDR_EN | DDR_4PHASE);
+		mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING,
+			     dpi->ddr_edge_sel ? EDGE_SEL : 0, EDGE_SEL);
+	}
+}
+
 static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 {
 	if (WARN_ON(dpi->refcount == 0))
@@ -455,7 +468,8 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	pll_rate = clk_get_rate(dpi->tvd_clk);
 
 	vm.pixelclock = pll_rate / factor;
-	clk_set_rate(dpi->pixel_clk, vm.pixelclock);
+	clk_set_rate(dpi->pixel_clk,
+		     vm.pixelclock * ((dpi->conf->num_output_fmts > 1) ? 2 : 1));
 	vm.pixelclock = clk_get_rate(dpi->pixel_clk);
 
 	dev_dbg(dpi->dev, "Got  PLL %lu Hz, pixel clock %lu Hz\n",
@@ -519,6 +533,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	mtk_dpi_config_yc_map(dpi, dpi->yc_map);
 	mtk_dpi_config_color_format(dpi, dpi->color_format);
 	mtk_dpi_config_2n_h_fre(dpi);
+	mtk_dpi_dual_edge(dpi);
 	mtk_dpi_config_disable_edge(dpi);
 	mtk_dpi_sw_reset(dpi, false);
 
-- 
2.18.0
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