diff options
| -rw-r--r-- | drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c index 480fdf256f01..89897d5f5c72 100644 --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c @@ -322,6 +322,103 @@ dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps, return 0; } +#define CLK_TOLERANCE_HZ 50 + +static enum drm_mode_status +dw_mipi_dsi_stm_mode_valid(void *priv_data, + const struct drm_display_mode *mode, + unsigned long mode_flags, u32 lanes, u32 format) +{ + struct dw_mipi_dsi_stm *dsi = priv_data; + unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz; + int ret, bpp; + + bpp = mipi_dsi_pixel_format_to_bpp(format); + if (bpp < 0) + return MODE_BAD; + + /* Compute requested pll out */ + pll_out_khz = mode->clock * bpp / lanes; + + if (pll_out_khz > dsi->lane_max_kbps) + return MODE_CLOCK_HIGH; + + if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST) { + /* Add 20% to pll out to be higher than pixel bw */ + pll_out_khz = (pll_out_khz * 12) / 10; + } else { + if (pll_out_khz < dsi->lane_min_kbps) + return MODE_CLOCK_LOW; + } + + /* Compute best pll parameters */ + idf = 0; + ndiv = 0; + odf = 0; + pll_in_khz = clk_get_rate(dsi->pllref_clk) / 1000; + ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz, &idf, &ndiv, &odf); + if (ret) { + DRM_WARN("Warning dsi_pll_get_params(): bad params\n"); + return MODE_ERROR; + } + + if (!(mode_flags & MIPI_DSI_MODE_VIDEO_BURST)) { + unsigned int px_clock_hz, target_px_clock_hz, lane_mbps; + int dsi_short_packet_size_px, hfp, hsync, hbp, delay_to_lp; + struct dw_mipi_dsi_dphy_timing dphy_timing; + + /* Get the adjusted pll out value */ + pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf); + + px_clock_hz = DIV_ROUND_CLOSEST_ULL(1000ULL * pll_out_khz * lanes, bpp); + target_px_clock_hz = mode->clock * 1000; + /* + * Filter modes according to the clock value, particularly useful for + * hdmi modes that require precise pixel clocks. + */ + if (px_clock_hz < target_px_clock_hz - CLK_TOLERANCE_HZ || + px_clock_hz > target_px_clock_hz + CLK_TOLERANCE_HZ) + return MODE_CLOCK_RANGE; + + /* sync packets are codes as DSI short packets (4 bytes) */ + dsi_short_packet_size_px = DIV_ROUND_UP(4 * BITS_PER_BYTE, bpp); + + hfp = mode->hsync_start - mode->hdisplay; + hsync = mode->hsync_end - mode->hsync_start; + hbp = mode->htotal - mode->hsync_end; + + /* hsync must be longer than 4 bytes HSS packets */ + if (hsync < dsi_short_packet_size_px) + return MODE_HSYNC_NARROW; + + if (mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) { + /* HBP must be longer than 4 bytes HSE packets */ + if (hbp < dsi_short_packet_size_px) + return MODE_HSYNC_NARROW; + hbp -= dsi_short_packet_size_px; + } else { + /* With sync events HBP extends in the hsync */ + hbp += hsync - dsi_short_packet_size_px; + } + + lane_mbps = pll_out_khz / 1000; + ret = dw_mipi_dsi_phy_get_timing(priv_data, lane_mbps, &dphy_timing); + if (ret) + return MODE_ERROR; + /* + * In non-burst mode DSI has to enter in LP during HFP + * (horizontal front porch) or HBP (horizontal back porch) to + * resync with LTDC pixel clock. + */ + delay_to_lp = DIV_ROUND_UP((dphy_timing.data_hs2lp + dphy_timing.data_lp2hs) * + lanes * BITS_PER_BYTE, bpp); + if (hfp < delay_to_lp && hbp < delay_to_lp) + return MODE_HSYNC; + } + + return MODE_OK; +} + static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = { .init = dw_mipi_dsi_phy_init, .power_on = dw_mipi_dsi_phy_power_on, @@ -332,6 +429,7 @@ static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = { static struct dw_mipi_dsi_plat_data dw_mipi_dsi_stm_plat_data = { .max_data_lanes = 2, + .mode_valid = dw_mipi_dsi_stm_mode_valid, .phy_ops = &dw_mipi_dsi_stm_phy_ops, }; |