drm/nouveau/dp: remove reliance on vbios for native displayport

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 110 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index f8ebd09ee3a6..ae1b6e00bd96 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -194,6 +194,116 @@ auxch_wr(struct drm_encoder *encoder, int address, uint8_t *buf, int size)
         return ret;
 }
 
+static u32
+dp_link_bw_get(struct drm_device *dev, int or, int link)
+{
+        u32 ctrl = nv_rd32(dev, 0x614300 + (or * 0x800));
+        if (!(ctrl & 0x000c0000))
+                return 162000;
+        return 270000;
+}
+
+static int
+dp_lane_count_get(struct drm_device *dev, int or, int link)
+{
+        u32 ctrl = nv_rd32(dev, NV50_SOR_DP_CTRL(or, link));
+        switch (ctrl & 0x000f0000) {
+        case 0x00010000: return 1;
+        case 0x00030000: return 2;
+        default:
+                return 4;
+        }
+}
+
+void
+nouveau_dp_tu_update(struct drm_device *dev, int or, int link, u32 clk, u32 bpp)
+{
+        const u32 symbol = 100000;
+        int bestTU = 0, bestVTUi = 0, bestVTUf = 0, bestVTUa = 0;
+        int TU, VTUi, VTUf, VTUa;
+        u64 link_data_rate, link_ratio, unk;
+        u32 best_diff = 64 * symbol;
+        u32 link_nr, link_bw, r;
+
+        /* calculate packed data rate for each lane */
+        link_nr = dp_lane_count_get(dev, or, link);
+        link_data_rate = (clk * bpp / 8) / link_nr;
+
+        /* calculate ratio of packed data rate to link symbol rate */
+        link_bw = dp_link_bw_get(dev, or, link);
+        link_ratio = link_data_rate * symbol;
+        r = do_div(link_ratio, link_bw);
+
+        for (TU = 64; TU >= 32; TU--) {
+                /* calculate average number of valid symbols in each TU */
+                u32 tu_valid = link_ratio * TU;
+                u32 calc, diff;
+
+                /* find a hw representation for the fraction.. */
+                VTUi = tu_valid / symbol;
+                calc = VTUi * symbol;
+                diff = tu_valid - calc;
+                if (diff) {
+                        if (diff >= (symbol / 2)) {
+                                VTUf = symbol / (symbol - diff);
+                                if (symbol - (VTUf * diff))
+                                        VTUf++;
+
+                                if (VTUf <= 15) {
+                                        VTUa  = 1;
+                                        calc += symbol - (symbol / VTUf);
+                                } else {
+                                        VTUa  = 0;
+                                        VTUf  = 1;
+                                        calc += symbol;
+                                }
+                        } else {
+                                VTUa  = 0;
+                                VTUf  = min((int)(symbol / diff), 15);
+                                calc += symbol / VTUf;
+                        }
+
+                        diff = calc - tu_valid;
+                } else {
+                        /* no remainder, but the hw doesn't like the fractional
+                         * part to be zero.  decrement the integer part and
+                         * have the fraction add a whole symbol back
+                         */
+                        VTUa = 0;
+                        VTUf = 1;
+                        VTUi--;
+                }
+
+                if (diff < best_diff) {
+                        best_diff = diff;
+                        bestTU = TU;
+                        bestVTUa = VTUa;
+                        bestVTUf = VTUf;
+                        bestVTUi = VTUi;
+                        if (diff == 0)
+                                break;
+                }
+        }
+
+        if (!bestTU) {
+                NV_ERROR(dev, "DP: unable to find suitable config\n");
+                return;
+        }
+
+        /* XXX close to vbios numbers, but not right */
+        unk  = (symbol - link_ratio) * bestTU;
+        unk *= link_ratio;
+        r = do_div(unk, symbol);
+        r = do_div(unk, symbol);
+        unk += 6;
+
+        nv_mask(dev, NV50_SOR_DP_CTRL(or, link), 0x000001fc, bestTU << 2);
+        nv_mask(dev, NV50_SOR_DP_SCFG(or, link), 0x010f7f3f, bestVTUa << 24 |
+                                                             bestVTUf << 16 |
+                                                             bestVTUi << 8 |
+                                                             unk);
+}
+
 static int
 nouveau_dp_lane_count_set(struct drm_encoder *encoder, uint8_t cmd)
 {
@@ -617,7 +727,6 @@ static int
 nouveau_dp_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 {
         struct nouveau_i2c_chan *auxch = (struct nouveau_i2c_chan *)adap;
-        struct drm_device *dev = auxch->dev;
         struct i2c_msg *msg = msgs;
         int ret, mcnt = num;