DPI sample the data both rising and falling edge.
It can reduce half data io pins.
Signed-off-by: Jitao Shi <jitao....@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 01fa8b8d763d..36e4dbd27d1b 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -75,6 +75,7 @@ struct mtk_dpi {
enum mtk_dpi_out_bit_num bit_num;
enum mtk_dpi_out_channel_swap channel_swap;
int refcount;
+ bool dual_edge;
};
static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
@@ -348,6 +349,13 @@ static void mtk_dpi_config_disable_edge(struct mtk_dpi
*dpi)
mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, 0, EDGE_SEL_EN);
}
+static void mtk_dpi_enable_dual_edge(struct mtk_dpi *dpi)
+{
+ mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
+ DDR_EN | DDR_4PHASE);
+ mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, EDGE_SEL, EDGE_SEL);
+}
+
static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
enum mtk_dpi_out_color_format format)
{
@@ -439,7 +447,8 @@ 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->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",
@@ -504,6 +513,8 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
mtk_dpi_config_color_format(dpi, dpi->color_format);
mtk_dpi_config_2n_h_fre(dpi);
mtk_dpi_config_disable_edge(dpi);
+ if (dpi->dual_edge)
+ mtk_dpi_enable_dual_edge(dpi);
mtk_dpi_sw_reset(dpi, false);
return 0;
@@ -689,6 +700,7 @@ static int mtk_dpi_probe(struct platform_device *pdev)
dpi->dev = dev;
dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev);
+ dpi->dual_edge = of_property_read_bool(dev->of_node, "dpi_dual_edge");
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dpi->regs = devm_ioremap_resource(dev, mem);
--
2.21.0
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