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.
Reviewed-by: CK Hu ck.hu@mediatek.com Signed-off-by: Jitao Shi jitao.shi@mediatek.com --- drivers/gpu/drm/mediatek/mtk_dpi.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 087f5ce732e1..db3272f7a4c4 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; + u32 pclk_sample; };
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_pclk_sample_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->pclk_sample > 1 ? 2 : 1)); vm.pixelclock = clk_get_rate(dpi->pixel_clk);
dev_dbg(dpi->dev, "Got PLL %lu Hz, pixel clock %lu Hz\n", @@ -450,7 +459,8 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi, limit.y_bottom = 0x0010; limit.y_top = 0x0FE0;
- dpi_pol.ck_pol = MTK_DPI_POLARITY_FALLING; + dpi_pol.ck_pol = dpi->pclk_sample == 1 ? + MTK_DPI_POLARITY_RISING : MTK_DPI_POLARITY_FALLING; dpi_pol.de_pol = MTK_DPI_POLARITY_RISING; dpi_pol.hsync_pol = vm.flags & DISPLAY_FLAGS_HSYNC_HIGH ? MTK_DPI_POLARITY_FALLING : MTK_DPI_POLARITY_RISING; @@ -504,6 +514,8 @@ 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->pclk_sample > 1) + mtk_dpi_enable_pclk_sample_dual_edge(dpi); mtk_dpi_sw_reset(dpi, false);
return 0; @@ -704,6 +716,8 @@ static int mtk_dpi_probe(struct platform_device *pdev)
dpi->dev = dev; dpi->conf = (struct mtk_dpi_conf *)of_device_get_match_data(dev); + of_property_read_u32_index(dev->of_node, "pclk-sample", 1, + &dpi->pclk_sample);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); dpi->regs = devm_ioremap_resource(dev, mem);