From: Abhinav Kumar <[email protected]>

DP MST streams share 64 MTP slots in a time-multiplexed manner. Add
support for calculating the rate governor, slot allocation, and slot
reservation in the DP controller.

Each MST stream can reserve its slots by calling
msm_dp_display_set_stream_info() from its bridge callbacks.

Signed-off-by: Abhinav Kumar <[email protected]>
Signed-off-by: Yongxing Mou <[email protected]>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c    | 192 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_ctrl.h    |   4 +
 drivers/gpu/drm/msm/dp/dp_display.c |  17 ++++
 drivers/gpu/drm/msm/dp/dp_display.h |   2 +
 drivers/gpu/drm/msm/dp/dp_panel.c   |   6 ++
 drivers/gpu/drm/msm/dp/dp_panel.h   |   1 +
 drivers/gpu/drm/msm/dp/dp_reg.h     |  10 ++
 7 files changed, 232 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 5b5149b160df..15df82a0caca 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -73,6 +73,7 @@
 #define MR_LINK_PRBS7 0x100
 #define MR_LINK_CUSTOM80 0x200
 #define MR_LINK_TRAINING4  0x40
+#define DP_MAX_TIME_SLOTS 64
 
 enum {
        DP_TRAINING_NONE,
@@ -109,6 +110,11 @@ struct msm_dp_vc_tu_mapping_table {
        u8 tu_size_minus1;
 };
 
+struct msm_dp_mst_ch_slot_info {
+       u32 start_slot;
+       u32 tot_slots;
+};
+
 struct msm_dp_ctrl_private {
        struct msm_dp_ctrl msm_dp_ctrl;
        struct drm_device *drm_dev;
@@ -143,6 +149,8 @@ struct msm_dp_ctrl_private {
        bool link_clks_on;
        bool stream_clks_on[DP_STREAM_MAX];
        bool mst_active;
+
+       struct msm_dp_mst_ch_slot_info mst_ch_info[DP_STREAM_MAX];
 };
 
 static inline u32 msm_dp_read_ahb(const struct msm_dp_ctrl_private *ctrl, u32 
offset)
@@ -289,6 +297,44 @@ static void msm_dp_ctrl_mst_config(struct 
msm_dp_ctrl_private *ctrl, bool enable
        msm_dp_write_link(ctrl, REG_DP_MAINLINK_CTRL, mainlink_ctrl);
 }
 
+static void msm_dp_ctrl_mst_channel_alloc(struct msm_dp_ctrl_private *ctrl,
+                                         enum msm_dp_stream_id stream_id, u32 
ch_start_slot,
+                                         u32 tot_slot_cnt)
+{
+       u32 slot_reg_1 = 0, slot_reg_2 = 0;
+
+       if (ch_start_slot > DP_MAX_TIME_SLOTS ||
+           (ch_start_slot + tot_slot_cnt > DP_MAX_TIME_SLOTS)) {
+               DRM_ERROR("invalid slots start %d, tot %d\n",
+                         ch_start_slot, tot_slot_cnt);
+               return;
+       }
+
+       drm_dbg_dp(ctrl->drm_dev, "stream_id %d, start_slot %d, tot_slot %d\n",
+                  stream_id, ch_start_slot, tot_slot_cnt);
+
+       if (ch_start_slot && tot_slot_cnt) {
+               u64 mask = GENMASK_ULL(ch_start_slot + tot_slot_cnt - 2, 
ch_start_slot - 1);
+
+               slot_reg_1 = mask & 0xFFFFFFFF;
+               slot_reg_2 = (mask >> 32) & 0xFFFFFFFF;
+       }
+
+       msm_dp_write_stream_link(ctrl, stream_id, REG_DP_DP0_TIMESLOT_1_32, 
slot_reg_1);
+       msm_dp_write_stream_link(ctrl, stream_id, REG_DP_DP0_TIMESLOT_33_63, 
slot_reg_2);
+}
+
+static void msm_dp_ctrl_update_rg(struct msm_dp_ctrl_private *ctrl,
+                                 enum msm_dp_stream_id stream_id, u32 x_int, 
u32 y_frac_enum)
+{
+       u32 rg = y_frac_enum | (x_int << 16);
+
+       drm_dbg_dp(ctrl->drm_dev, "stream_id: %d x_int:%d y_frac_enum:%d 
rg:%d\n",
+                  stream_id, x_int, y_frac_enum, rg);
+
+       msm_dp_write_stream_link(ctrl, stream_id, REG_DP_DP0_RG, rg);
+}
+
 /*
  * NOTE: resetting DP controller will also clear any pending HPD related 
interrupts
  */
@@ -2619,6 +2665,117 @@ static void msm_dp_ctrl_config_msa(struct 
msm_dp_ctrl_private *ctrl,
        msm_dp_write_stream_link(ctrl, panel->stream_id, REG_DP_SOFTWARE_NVID, 
nvid);
 }
 
+/*
+ * Calculate MST Rate Governor parameters x_int and y_frac_enum (HPG 3.8.1.2).
+ *
+ * The RG paces symbol delivery per MTP via: M = x_int + y_frac_enum/256
+ * where M is the target symbol count per MTP across all lanes.
+ *
+ * min_slot_cnt = (pclk * bpp/8) / (lclk * lanes) * 64   -- slots at 1.0x BW
+ * max_slot_cnt = pbn * 54 / (lclk * lanes)               -- slots at PBN limit
+ * raw_target_sc = (min + max) / 2                        -- midpoint (~1.003x)
+ *
+ * Quantize raw_target_sc to 1/(256*lanes) steps, then:
+ *   M           = Chosen_TARGET_Slot_Count * lanes
+ *   x_int       = INT(M)
+ *   y_frac_enum = CEIL(256 * MOD(M, 1))
+ */
+static void msm_dp_ctrl_mst_calculate_rg(struct msm_dp_ctrl_private *ctrl,
+                                        struct msm_dp_panel *panel,
+                                        u32 *p_x_int, u32 *p_y_frac_enum)
+{
+       u64 min_slot_cnt, max_slot_cnt;
+       u64 raw_target_sc, target_sc_fixp;
+       u64 ts_denom, ts_enum, ts_int;
+       u64 pclk = panel->msm_dp_mode.drm_mode.clock;
+       u64 lclk = 0;
+       u64 lanes = ctrl->link->link_params.num_lanes;
+       u64 bpp = panel->msm_dp_mode.bpp;
+       u64 pbn = panel->pbn;
+       u64 numerator, denominator, temp, temp1, temp2;
+       u32 x_int = 0, y_frac_enum = 0;
+       u64 target_strm_sym, ts_int_fixp, ts_frac_fixp, y_frac_enum_fixp;
+
+       lclk = ctrl->link->link_params.rate;
+
+       /* min_slot_cnt */
+       numerator = pclk * bpp * 64 * 1000;
+       denominator = lclk * lanes * 8 * 1000;
+       min_slot_cnt = drm_fixp_from_fraction(numerator, denominator);
+
+       /* max_slot_cnt */
+       numerator = pbn * 54 * 1000;
+       denominator = lclk * lanes;
+       max_slot_cnt = drm_fixp_from_fraction(numerator, denominator);
+
+       /* raw_target_sc */
+       numerator = max_slot_cnt + min_slot_cnt;
+       denominator = drm_fixp_from_fraction(2, 1);
+       raw_target_sc = drm_fixp_div(numerator, denominator);
+
+       /* target_sc */
+       temp = drm_fixp_from_fraction(256 * lanes, 1);
+       numerator = drm_fixp_mul(raw_target_sc, temp);
+       denominator = drm_fixp_from_fraction(256 * lanes, 1);
+       target_sc_fixp = drm_fixp_div(numerator, denominator);
+
+       ts_enum = 256 * lanes;
+       ts_denom = drm_fixp_from_fraction(256 * lanes, 1);
+       ts_int = drm_fixp2int(target_sc_fixp);
+
+       temp = drm_fixp2int_ceil(raw_target_sc);
+       if (temp != ts_int) {
+               temp = drm_fixp_from_fraction(ts_int, 1);
+               temp1 = raw_target_sc - temp;
+               temp2 = drm_fixp_mul(temp1, ts_denom);
+               ts_enum = drm_fixp2int(temp2);
+       }
+
+       /* target_strm_sym */
+       ts_int_fixp = drm_fixp_from_fraction(ts_int, 1);
+       ts_frac_fixp = drm_fixp_from_fraction(ts_enum, drm_fixp2int(ts_denom));
+       temp = ts_int_fixp + ts_frac_fixp;
+       temp1 = drm_fixp_from_fraction(lanes, 1);
+       target_strm_sym = drm_fixp_mul(temp, temp1);
+
+       /* x_int */
+       x_int = drm_fixp2int(target_strm_sym);
+
+       /* y_enum_frac */
+       temp = drm_fixp_from_fraction(x_int, 1);
+       temp1 = target_strm_sym - temp;
+       temp2 = drm_fixp_from_fraction(256, 1);
+       y_frac_enum_fixp = drm_fixp_mul(temp1, temp2);
+
+       temp1 = drm_fixp2int(y_frac_enum_fixp);
+       temp2 = drm_fixp2int_ceil(y_frac_enum_fixp);
+
+       y_frac_enum = (u32)((temp1 == temp2) ? temp1 : temp1 + 1);
+
+       *p_x_int = x_int;
+       *p_y_frac_enum = y_frac_enum;
+
+       drm_dbg_dp(ctrl->drm_dev, "MST lane_cnt:%llu, rate:%llu x_int:%d, 
y_frac:%d\n",
+                  lanes, lclk, x_int, y_frac_enum);
+}
+
+static void msm_dp_ctrl_mst_stream_setup(struct msm_dp_ctrl_private *ctrl,
+                                        struct msm_dp_panel *panel)
+{
+       u32 x_int, y_frac_enum;
+
+       if (!ctrl->mst_active)
+               return;
+
+       drm_dbg_dp(ctrl->drm_dev, "MST stream channel allocation\n");
+
+       msm_dp_ctrl_mst_stream_channel_slot_setup(&ctrl->msm_dp_ctrl);
+
+       msm_dp_ctrl_mst_calculate_rg(ctrl, panel, &x_int, &y_frac_enum);
+
+       msm_dp_ctrl_update_rg(ctrl, panel->stream_id, x_int, y_frac_enum);
+}
+
 int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *msm_dp_ctrl,
                                  struct msm_dp_panel *panel,
                                  bool force_link_train)
@@ -2708,6 +2865,8 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl 
*msm_dp_ctrl, struct msm_dp_panel *
        if (!ctrl->mst_active)
                msm_dp_ctrl_setup_tr_unit(ctrl, panel);
 
+       msm_dp_ctrl_mst_stream_setup(ctrl, panel);
+
        msm_dp_write_link(ctrl, REG_DP_STATE_CTRL, DP_STATE_CTRL_SEND_VIDEO);
 
        ret = msm_dp_ctrl_mst_send_act(msm_dp_ctrl, panel);
@@ -2760,6 +2919,39 @@ void msm_dp_ctrl_off_link(struct msm_dp_ctrl 
*msm_dp_ctrl,
        phy_power_off(phy);
 }
 
+void msm_dp_ctrl_set_mst_channel_info(struct msm_dp_ctrl *msm_dp_ctrl,
+                                     enum msm_dp_stream_id stream_id,
+                                     u32 start_slot, u32 tot_slots)
+{
+       struct msm_dp_ctrl_private *ctrl;
+
+       if (!msm_dp_ctrl || stream_id >= DP_STREAM_MAX) {
+               DRM_ERROR("invalid input\n");
+               return;
+       }
+
+       ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, 
msm_dp_ctrl);
+
+       ctrl->mst_ch_info[stream_id].start_slot = start_slot;
+       ctrl->mst_ch_info[stream_id].tot_slots = tot_slots;
+}
+
+void msm_dp_ctrl_mst_stream_channel_slot_setup(struct msm_dp_ctrl *msm_dp_ctrl)
+{
+       struct msm_dp_ctrl_private *ctrl;
+       int i;
+
+       ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, 
msm_dp_ctrl);
+
+       if (!ctrl->mst_active)
+               return;
+
+       for (i = DP_STREAM_0; i < ctrl->num_pixel_clks; i++) {
+               msm_dp_ctrl_mst_channel_alloc(ctrl, i, 
ctrl->mst_ch_info[i].start_slot,
+                                             ctrl->mst_ch_info[i].tot_slots);
+       }
+}
+
 irqreturn_t msm_dp_ctrl_isr(struct msm_dp_ctrl *msm_dp_ctrl,
                            struct msm_dp_panel *panel)
 {
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
index 6de028da85fb..e1d10ae20f70 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
@@ -61,4 +61,8 @@ void msm_dp_ctrl_reinit_phy(struct msm_dp_ctrl *msm_dp_ctrl);
 int msm_dp_ctrl_get_stream_cnt(struct msm_dp_ctrl *dp_ctrl);
 int msm_dp_ctrl_mst_send_act(struct msm_dp_ctrl *msm_dp_ctrl,
                             struct msm_dp_panel *panel);
+void msm_dp_ctrl_mst_stream_channel_slot_setup(struct msm_dp_ctrl 
*msm_dp_ctrl);
+void msm_dp_ctrl_set_mst_channel_info(struct msm_dp_ctrl *msm_dp_ctrl,
+                                     enum msm_dp_stream_id stream_id,
+                                     u32 start_slot, u32 tot_slots);
 #endif /* _DP_CTRL_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c 
b/drivers/gpu/drm/msm/dp/dp_display.c
index acb581a8a541..36857d6ed313 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -749,6 +749,20 @@ static int msm_dp_display_disable(struct 
msm_dp_display_private *dp,
        return 0;
 }
 
+int msm_dp_display_set_stream_info(struct msm_dp *msm_dp_display, struct 
msm_dp_panel *panel,
+                                  u32 start_slot, u32 num_slots, u32 pbn)
+{
+       struct msm_dp_display_private *dp;
+
+       dp = container_of(msm_dp_display, struct msm_dp_display_private, 
msm_dp_display);
+
+       msm_dp_ctrl_set_mst_channel_info(dp->ctrl, panel->stream_id, 
start_slot, num_slots);
+
+       panel->pbn = pbn;
+
+       return 0;
+}
+
 /**
  * msm_dp_bridge_mode_valid - callback to determine if specified mode is valid
  * @dp: Pointer to dp display structure
@@ -1489,6 +1503,8 @@ void msm_dp_display_atomic_enable(struct msm_dp 
*msm_dp_display)
 
        dp = container_of(msm_dp_display, struct msm_dp_display_private, 
msm_dp_display);
 
+       msm_dp_display_set_stream_info(msm_dp_display, dp->panel, 0, 0, 0);
+
        rc = msm_dp_display_enable(dp, dp->panel);
        if (rc)
                DRM_ERROR("DP display enable failed, rc=%d\n", rc);
@@ -1509,6 +1525,7 @@ void msm_dp_display_atomic_disable(struct msm_dp *dp)
        msm_dp_display = container_of(dp, struct msm_dp_display_private, 
msm_dp_display);
 
        msm_dp_ctrl_push_idle(msm_dp_display->ctrl);
+       msm_dp_ctrl_mst_stream_channel_slot_setup(msm_dp_display->ctrl);
        msm_dp_ctrl_mst_send_act(msm_dp_display->ctrl, msm_dp_display->panel);
 }
 
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h 
b/drivers/gpu/drm/msm/dp/dp_display.h
index e987de80522c..45e2cc2d6add 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -43,5 +43,7 @@ void msm_dp_display_atomic_enable(struct msm_dp *dp_display);
 enum drm_mode_status msm_dp_display_mode_valid(struct msm_dp *dp,
                                               const struct drm_display_info 
*info,
                                               const struct drm_display_mode 
*mode);
+int msm_dp_display_set_stream_info(struct msm_dp *msm_dp_display, struct 
msm_dp_panel *panel,
+                                  u32 start_slot, u32 num_slots, u32 pbn);
 
 #endif /* _DP_DISPLAY_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c 
b/drivers/gpu/drm/msm/dp/dp_panel.c
index e0c0e8c9178c..ef2ded8ec4ea 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -57,6 +57,12 @@ u32 msm_dp_stream_reg(enum msm_dp_stream_id id, u32 reg)
                return is_s1 ? REG_DP1_ACTIVE_HOR_VER : 
REG_DP_MSTLINK_ACTIVE_HOR_VER;
        case REG_DP_MISC1_MISC0:
                return is_s1 ? REG_DP1_MISC1_MISC0 : REG_DP_MSTLINK_MISC1_MISC0;
+       case REG_DP_DP0_TIMESLOT_1_32:
+               return is_s1 ? REG_DP_DP1_TIMESLOT_1_32 : 
REG_DP_MSTLINK_TIMESLOT_1_32;
+       case REG_DP_DP0_TIMESLOT_33_63:
+               return is_s1 ? REG_DP_DP1_TIMESLOT_33_63 : 
REG_DP_MSTLINK_TIMESLOT_33_63;
+       case REG_DP_DP0_RG:
+               return is_s1 ? REG_DP_DP1_RG : REG_DP_MSTLINK_DP_RG;
        case MMSS_DP_SDP_CFG:
                return is_s1 ? MMSS_DP1_SDP_CFG : MMSS_DP_MSTLINK_SDP_CFG;
        case MMSS_DP_SDP_CFG2:
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h 
b/drivers/gpu/drm/msm/dp/dp_panel.h
index dc046fec24fc..3e78af9e430d 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -50,6 +50,7 @@ struct msm_dp_panel {
        u32 hw_revision;
 
        enum msm_dp_stream_id stream_id;
+       u32 pbn;
 
        u32 max_bw_code;
 };
diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h b/drivers/gpu/drm/msm/dp/dp_reg.h
index deb40ed24654..f2bd96f3bbd0 100644
--- a/drivers/gpu/drm/msm/dp/dp_reg.h
+++ b/drivers/gpu/drm/msm/dp/dp_reg.h
@@ -338,7 +338,13 @@
 #define DP_TPG_VIDEO_CONFIG_BPP_8BIT           (0x00000001)
 #define DP_TPG_VIDEO_CONFIG_RGB                        (0x00000004)
 
+
+#define REG_DP_MSTLINK_DP_RG                   (0X0000011C)
 #define REG_DP1_CONFIGURATION_CTRL             (0x00000400)
+#define REG_DP_DP0_TIMESLOT_1_32               (0x00000404)
+#define REG_DP_DP0_TIMESLOT_33_63              (0x00000408)
+#define REG_DP_DP1_TIMESLOT_1_32               (0x0000040C)
+#define REG_DP_DP1_TIMESLOT_33_63              (0x00000410)
 #define REG_DP1_SOFTWARE_MVID                  (0x00000414)
 #define REG_DP1_SOFTWARE_NVID                  (0x00000418)
 #define REG_DP1_TOTAL_HOR_VER                  (0x0000041C)
@@ -359,8 +365,12 @@
 #define MMSS_DP1_SDP_CFG                       (0x000004E0)
 #define MMSS_DP1_SDP_CFG2                      (0x000004E4)
 #define MMSS_DP1_SDP_CFG3                      (0x000004E8)
+#define REG_DP_DP0_RG                          (0x000004F8)
+#define REG_DP_DP1_RG                          (0x000004FC)
 
 #define REG_DP_MSTLINK_CONFIGURATION_CTRL      (0x00000034)
+#define REG_DP_MSTLINK_TIMESLOT_1_32           (0x00000038)
+#define REG_DP_MSTLINK_TIMESLOT_33_63          (0x0000003C)
 #define REG_MSTLINK_SOFTWARE_MVID              (0x00000040)
 #define REG_MSTLINK_SOFTWARE_NVID              (0x00000044)
 #define REG_DP_MSTLINK_TOTAL_HOR_VER           (0x00000048)

-- 
2.43.0

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