[v3 RESEND, PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

[Rex-BC Chen]

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.

Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index b05f900d9322..79f3e83f40ef 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;
 };
 
@@ -121,6 +122,7 @@ struct mtk_dpi_conf {
 	unsigned int (*cal_factor)(int clock);
 	u32 reg_h_fre_con;
 	bool edge_sel_en;
+	bool dual_edge;
 };
 
 static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
 	}
 }
 
+static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
+{
+	if (dpi->conf->dual_edge) {
+		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))
@@ -454,7 +465,7 @@ 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->dual_edge ? 2 : 1));
 	vm.pixelclock = clk_get_rate(dpi->pixel_clk);
 
 	dev_dbg(dpi->dev, "Got  PLL %lu Hz, pixel clock %lu Hz\n",
@@ -518,6 +529,7 @@ 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