drm/msm/dsi: Add new method to calculate 14nm PHY timings

The 14nm DSI PHY on 8x96 (called PHY v2 downstream) requires a different
set of calculations for computing D-PHY timing params. Create a
timing_calc_v2 func for the newer v2 PHYs.

Signed-off-by: Hai Li <hali@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/dsi/phy/dsi_phy.c

@@ -148,6 +148,123 @@ int msm_dsi_dphy_timing_calc(struct msm_dsi_dphy_timing *timing,
 	return 0;
 }
 
+int msm_dsi_dphy_timing_calc_v2(struct msm_dsi_dphy_timing *timing,
+				struct msm_dsi_phy_clk_request *clk_req)
+{
+	const unsigned long bit_rate = clk_req->bitclk_rate;
+	const unsigned long esc_rate = clk_req->escclk_rate;
+	s32 ui, ui_x8, lpx;
+	s32 tmax, tmin;
+	s32 pcnt0 = 50;
+	s32 pcnt1 = 50;
+	s32 pcnt2 = 10;
+	s32 pcnt3 = 30;
+	s32 pcnt4 = 10;
+	s32 pcnt5 = 2;
+	s32 coeff = 1000; /* Precision, should avoid overflow */
+	s32 hb_en, hb_en_ckln, pd_ckln, pd;
+	s32 val, val_ckln;
+	s32 temp;
+
+	if (!bit_rate || !esc_rate)
+		return -EINVAL;
+
+	timing->hs_halfbyte_en = 0;
+	hb_en = 0;
+	timing->hs_halfbyte_en_ckln = 0;
+	hb_en_ckln = 0;
+	timing->hs_prep_dly_ckln = (bit_rate > 100000000) ? 0 : 3;
+	pd_ckln = timing->hs_prep_dly_ckln;
+	timing->hs_prep_dly = (bit_rate > 120000000) ? 0 : 1;
+	pd = timing->hs_prep_dly;
+
+	val = (hb_en << 2) + (pd << 1);
+	val_ckln = (hb_en_ckln << 2) + (pd_ckln << 1);
+
+	ui = mult_frac(NSEC_PER_MSEC, coeff, bit_rate / 1000);
+	ui_x8 = ui << 3;
+	lpx = mult_frac(NSEC_PER_MSEC, coeff, esc_rate / 1000);
+
+	temp = S_DIV_ROUND_UP(38 * coeff - val_ckln * ui, ui_x8);
+	tmin = max_t(s32, temp, 0);
+	temp = (95 * coeff - val_ckln * ui) / ui_x8;
+	tmax = max_t(s32, temp, 0);
+	timing->clk_prepare = linear_inter(tmax, tmin, pcnt0, 0, false);
+
+	temp = 300 * coeff - ((timing->clk_prepare << 3) + val_ckln) * ui;
+	tmin = S_DIV_ROUND_UP(temp - 11 * ui, ui_x8) - 3;
+	tmax = (tmin > 255) ? 511 : 255;
+	timing->clk_zero = linear_inter(tmax, tmin, pcnt5, 0, false);
+
+	tmin = DIV_ROUND_UP(60 * coeff + 3 * ui, ui_x8);
+	temp = 105 * coeff + 12 * ui - 20 * coeff;
+	tmax = (temp + 3 * ui) / ui_x8;
+	timing->clk_trail = linear_inter(tmax, tmin, pcnt3, 0, false);
+
+	temp = S_DIV_ROUND_UP(40 * coeff + 4 * ui - val * ui, ui_x8);
+	tmin = max_t(s32, temp, 0);
+	temp = (85 * coeff + 6 * ui - val * ui) / ui_x8;
+	tmax = max_t(s32, temp, 0);
+	timing->hs_prepare = linear_inter(tmax, tmin, pcnt1, 0, false);
+
+	temp = 145 * coeff + 10 * ui - ((timing->hs_prepare << 3) + val) * ui;
+	tmin = S_DIV_ROUND_UP(temp - 11 * ui, ui_x8) - 3;
+	tmax = 255;
+	timing->hs_zero = linear_inter(tmax, tmin, pcnt4, 0, false);
+
+	tmin = DIV_ROUND_UP(60 * coeff + 4 * ui + 3 * ui, ui_x8);
+	temp = 105 * coeff + 12 * ui - 20 * coeff;
+	tmax = (temp + 3 * ui) / ui_x8;
+	timing->hs_trail = linear_inter(tmax, tmin, pcnt3, 0, false);
+
+	temp = 50 * coeff + ((hb_en << 2) - 8) * ui;
+	timing->hs_rqst = S_DIV_ROUND_UP(temp, ui_x8);
+
+	tmin = DIV_ROUND_UP(100 * coeff, ui_x8) - 1;
+	tmax = 255;
+	timing->hs_exit = linear_inter(tmax, tmin, pcnt2, 0, false);
+
+	temp = 50 * coeff + ((hb_en_ckln << 2) - 8) * ui;
+	timing->hs_rqst_ckln = S_DIV_ROUND_UP(temp, ui_x8);
+
+	temp = 60 * coeff + 52 * ui - 43 * ui;
+	tmin = DIV_ROUND_UP(temp, ui_x8) - 1;
+	tmax = 63;
+	timing->shared_timings.clk_post =
+				linear_inter(tmax, tmin, pcnt2, 0, false);
+
+	temp = 8 * ui + ((timing->clk_prepare << 3) + val_ckln) * ui;
+	temp += (((timing->clk_zero + 3) << 3) + 11 - (pd_ckln << 1)) * ui;
+	temp += hb_en_ckln ? (((timing->hs_rqst_ckln << 3) + 4) * ui) :
+				(((timing->hs_rqst_ckln << 3) + 8) * ui);
+	tmin = S_DIV_ROUND_UP(temp, ui_x8) - 1;
+	tmax = 63;
+	if (tmin > tmax) {
+		temp = linear_inter(tmax << 1, tmin, pcnt2, 0, false);
+		timing->shared_timings.clk_pre = temp >> 1;
+		timing->shared_timings.clk_pre_inc_by_2 = 1;
+	} else {
+		timing->shared_timings.clk_pre =
+				linear_inter(tmax, tmin, pcnt2, 0, false);
+		timing->shared_timings.clk_pre_inc_by_2 = 0;
+	}
+
+	timing->ta_go = 3;
+	timing->ta_sure = 0;
+	timing->ta_get = 4;
+
+	DBG("%d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d",
+	    timing->shared_timings.clk_pre, timing->shared_timings.clk_post,
+	    timing->shared_timings.clk_pre_inc_by_2, timing->clk_zero,
+	    timing->clk_trail, timing->clk_prepare, timing->hs_exit,
+	    timing->hs_zero, timing->hs_prepare, timing->hs_trail,
+	    timing->hs_rqst, timing->hs_rqst_ckln, timing->hs_halfbyte_en,
+	    timing->hs_halfbyte_en_ckln, timing->hs_prep_dly,
+	    timing->hs_prep_dly_ckln);
+
+	return 0;
+}
+
 void msm_dsi_phy_set_src_pll(struct msm_dsi_phy *phy, int pll_id, u32 reg,
 				u32 bit_mask)
 {

drivers/gpu/drm/msm/dsi/phy/dsi_phy.h

@@ -64,6 +64,13 @@ struct msm_dsi_dphy_timing {
 	u32 ta_get;
 
 	struct msm_dsi_phy_shared_timings shared_timings;
+
+	/* For PHY v2 only */
+	u32 hs_rqst_ckln;
+	u32 hs_prep_dly;
+	u32 hs_prep_dly_ckln;
+	u8 hs_halfbyte_en;
+	u8 hs_halfbyte_en_ckln;
 };
 
 struct msm_dsi_phy {
@@ -88,7 +95,9 @@ struct msm_dsi_phy {
  * PHY internal functions
  */
 int msm_dsi_dphy_timing_calc(struct msm_dsi_dphy_timing *timing,
-	struct msm_dsi_phy_clk_request *clk_req);
+			     struct msm_dsi_phy_clk_request *clk_req);
+int msm_dsi_dphy_timing_calc_v2(struct msm_dsi_dphy_timing *timing,
+				struct msm_dsi_phy_clk_request *clk_req);
 void msm_dsi_phy_set_src_pll(struct msm_dsi_phy *phy, int pll_id, u32 reg,
 				u32 bit_mask);
 int msm_dsi_phy_init_common(struct msm_dsi_phy *phy);