On Tue, 14 Feb 2017, Madhav Chauhan <madhav.chauhan@xxxxxxxxx> wrote: > From: Deepak M <m.deepak@xxxxxxxxx> > > For GEMINILAKE, dphy param reg values are programmed in terms > of HS byte clock count while for older platforms in terms of > HS ddr clk count. > > v2: Added comments to clarify ddr clock count calculation > v3: Use multiplier variable instead of IS_GEMINILAKE() > check everywhere (Jani) > > Signed-off-by: Deepak M <m.deepak@xxxxxxxxx> > Signed-off-by: Madhav Chauhan <madhav.chauhan@xxxxxxxxx> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_dsi_panel_vbt.c | 31 +++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c > index 8f683b8..d06e7f7 100644 > --- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c > +++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c > @@ -571,6 +571,7 @@ struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id) > u32 tclk_prepare_clkzero, ths_prepare_hszero; > u32 lp_to_hs_switch, hs_to_lp_switch; > u32 pclk, computed_ddr; > + u32 mul; > u16 burst_mode_ratio; > enum port port; > > @@ -674,11 +675,6 @@ struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id) > break; > } > > - /* > - * ui(s) = 1/f [f in hz] > - * ui(ns) = 10^9 / (f*10^6) [f in Mhz] -> 10^3/f(Mhz) > - */ > - > /* in Kbps */ > ui_num = NS_KHZ_RATIO; > ui_den = bitrate; > @@ -692,21 +688,26 @@ struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id) > */ > intel_dsi->lp_byte_clk = DIV_ROUND_UP(tlpx_ns * ui_den, 8 * ui_num); > > - /* count values in UI = (ns value) * (bitrate / (2 * 10^6)) > + /* DDR clock period = 2 * UI > + * UI(sec) = 1/(bitrate * 10^3) (bitrate is in KHZ) > + * UI(nsec) = 10^6 / bitrate > + * DDR clock period (nsec) = 2 * UI = (2 * 10^6)/ bitrate > + * DDR clock count = ns_value / DDR clock period > * > - * Since txddrclkhs_i is 2xUI, all the count values programmed in > - * DPHY param register are divided by 2 > - * > - * prepare count > + * For GEMINILAKE dphy_param_reg will be programmed in terms of > + * HS byte clock count for other platform in HS ddr clock count > */ > + mul = IS_GEMINILAKE(dev_priv) ? 8 : 2; > ths_prepare_ns = max(mipi_config->ths_prepare, > mipi_config->tclk_prepare); > - prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * ui_den, ui_num * 2); > + > + /* prepare count */ > + prepare_cnt = DIV_ROUND_UP(ths_prepare_ns * ui_den, ui_num * mul); > > /* exit zero count */ > exit_zero_cnt = DIV_ROUND_UP( > (ths_prepare_hszero - ths_prepare_ns) * ui_den, > - ui_num * 2 > + ui_num * mul > ); > > /* > @@ -720,12 +721,12 @@ struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id) > > /* clk zero count */ > clk_zero_cnt = DIV_ROUND_UP( > - (tclk_prepare_clkzero - ths_prepare_ns) > - * ui_den, 2 * ui_num); > + (tclk_prepare_clkzero - ths_prepare_ns) > + * ui_den, ui_num * mul); > > /* trail count */ > tclk_trail_ns = max(mipi_config->tclk_trail, mipi_config->ths_trail); > - trail_cnt = DIV_ROUND_UP(tclk_trail_ns * ui_den, 2 * ui_num); > + trail_cnt = DIV_ROUND_UP(tclk_trail_ns * ui_den, ui_num * mul); > > if (prepare_cnt > PREPARE_CNT_MAX || > exit_zero_cnt > EXIT_ZERO_CNT_MAX || -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
