xlnx_dp: Introduce a vblank signal

Add a periodic timer which raises vblank at a frequency of 30Hz.

Note that this is a migration compatibility break for the
xlnx-zcu102 board type.

Signed-off-by: Sai Pavan Boddu <saipava@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Frederic Konrad <fkonrad@amd.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220601172353.3220232-3-fkonrad@xilinx.com
Changes by fkonrad:
  - Switched to transaction-based ptimer API.
  - Added the DP_INT_VBLNK_START macro.
Signed-off-by: Frederic Konrad <fkonrad@amd.com>
[PMM: bump vmstate version, add commit message note about
 compat break]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 26 insertions, 4 deletions

diff --git a/hw/display/xlnx_dp.c b/hw/display/xlnx_dp.c
index 0378570..ed856b5 100644
--- a/hw/display/xlnx_dp.c
+++ b/hw/display/xlnx_dp.c
@@ -114,6 +114,7 @@
 #define DP_TX_N_AUD                         (0x032C >> 2)
 #define DP_TX_AUDIO_EXT_DATA(n)             ((0x0330 + 4 * n) >> 2)
 #define DP_INT_STATUS                       (0x03A0 >> 2)
+#define DP_INT_VBLNK_START                  (1 << 13)
 #define DP_INT_MASK                         (0x03A4 >> 2)
 #define DP_INT_EN                           (0x03A8 >> 2)
 #define DP_INT_DS                           (0x03AC >> 2)
@@ -260,7 +261,7 @@ typedef enum DPVideoFmt DPVideoFmt;
 
 static const VMStateDescription vmstate_dp = {
     .name = TYPE_XLNX_DP,
-    .version_id = 1,
+    .version_id = 2,
     .fields = (VMStateField[]){
         VMSTATE_UINT32_ARRAY(core_registers, XlnxDPState,
                              DP_CORE_REG_ARRAY_SIZE),
@@ -270,10 +271,15 @@ static const VMStateDescription vmstate_dp = {
                              DP_VBLEND_REG_ARRAY_SIZE),
         VMSTATE_UINT32_ARRAY(audio_registers, XlnxDPState,
                              DP_AUDIO_REG_ARRAY_SIZE),
+        VMSTATE_PTIMER(vblank, XlnxDPState),
         VMSTATE_END_OF_LIST()
     }
 };
 
+#define DP_VBLANK_PTIMER_POLICY (PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD | \
+                                 PTIMER_POLICY_CONTINUOUS_TRIGGER |    \
+                                 PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)
+
 static void xlnx_dp_update_irq(XlnxDPState *s);
 
 static uint64_t xlnx_dp_audio_read(void *opaque, hwaddr offset, unsigned size)
@@ -773,6 +779,13 @@ static void xlnx_dp_write(void *opaque, hwaddr offset, uint64_t value,
         break;
     case DP_TRANSMITTER_ENABLE:
         s->core_registers[offset] = value & 0x01;
+        ptimer_transaction_begin(s->vblank);
+        if (value & 0x1) {
+            ptimer_run(s->vblank, 0);
+        } else {
+            ptimer_stop(s->vblank);
+        }
+        ptimer_transaction_commit(s->vblank);
         break;
     case DP_FORCE_SCRAMBLER_RESET:
         /*
@@ -1177,9 +1190,6 @@ static void xlnx_dp_update_display(void *opaque)
         return;
     }
 
-    s->core_registers[DP_INT_STATUS] |= (1 << 13);
-    xlnx_dp_update_irq(s);
-
     xlnx_dpdma_trigger_vsync_irq(s->dpdma);
 
     /*
@@ -1275,6 +1285,14 @@ static void xlnx_dp_finalize(Object *obj)
     fifo8_destroy(&s->rx_fifo);
 }
 
+static void vblank_hit(void *opaque)
+{
+    XlnxDPState *s = XLNX_DP(opaque);
+
+    s->core_registers[DP_INT_STATUS] |= DP_INT_VBLNK_START;
+    xlnx_dp_update_irq(s);
+}
+
 static void xlnx_dp_realize(DeviceState *dev, Error **errp)
 {
     XlnxDPState *s = XLNX_DP(dev);
@@ -1309,6 +1327,10 @@ static void xlnx_dp_realize(DeviceState *dev, Error **errp)
                                            &as);
     AUD_set_volume_out(s->amixer_output_stream, 0, 255, 255);
     xlnx_dp_audio_activate(s);
+    s->vblank = ptimer_init(vblank_hit, s, DP_VBLANK_PTIMER_POLICY);
+    ptimer_transaction_begin(s->vblank);
+    ptimer_set_freq(s->vblank, 30);
+    ptimer_transaction_commit(s->vblank);
 }
 
 static void xlnx_dp_reset(DeviceState *dev)