Gowin. Implement MIPI IO.

Adds output (MIPI_OBUF and MIPI_OBUF_A) and input (MIPI_IBUF) primitives to allow the use of “real” MIPI (not emulation) ports capable of operating in both HS and LP modes. Signed-off-by: YRabbit <[email protected]>
yrabbit · Jan 23, 2025 · 1708999 · 1708999
1 parent 1623243
commit 1708999
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Showing 6 changed files with 245 additions and 10 deletions.
diff --git a/himbaechel/uarch/gowin/constids.inc b/himbaechel/uarch/gowin/constids.inc
@@ -1313,6 +1313,16 @@ X(LSREN)
 // EMCU
 X(EMCU)
 
+// MIPI
+X(IL)
+X(OH)
+X(OL)
+X(OENB)
+X(MIPI_IBUF)
+X(MIPI_OBUF)
+X(MIPI_OBUF_A)
+X(MODESEL)
+
 // Register placement options
 X(IREG_IN_IOB)
 X(OREG_IN_IOB)

diff --git a/himbaechel/uarch/gowin/globals.cc b/himbaechel/uarch/gowin/globals.cc
@@ -243,6 +243,10 @@ struct GowinGlobalRouter
     bool driver_is_dqce(const PortRef &driver) { return CellTypePort(driver) == CellTypePort(id_DQCE, id_CLKOUT); }
     bool driver_is_dcs(const PortRef &driver) { return CellTypePort(driver) == CellTypePort(id_DCS, id_CLKOUT); }
     bool driver_is_dhcen(const PortRef &driver) { return CellTypePort(driver) == CellTypePort(id_DHCEN, id_CLKOUT); }
+    bool driver_is_mipi(const PortRef &driver)
+    {
+        return CellTypePort(driver) == CellTypePort(id_IOBUF, id_O) && driver.cell->params.count(id_MIPI_IBUF);
+    }
     bool driver_is_clksrc(const PortRef &driver)
     {
         // dedicated pins
@@ -506,7 +510,7 @@ struct GowinGlobalRouter
         NPNR_ASSERT(net_before_dhcen != nullptr);
 
         PortRef driver = net_before_dhcen->driver;
-        NPNR_ASSERT_MSG(driver_is_buf(driver) || driver_is_clksrc(driver),
+        NPNR_ASSERT_MSG(driver_is_buf(driver) || driver_is_clksrc(driver) || driver_is_mipi(driver),
                         stringf("The input source for %s is not a clock.", ctx->nameOf(dhcen_ci)).c_str());
 
         IdString port;
@@ -519,8 +523,14 @@ struct GowinGlobalRouter
         WireId src = ctx->getBelPinWire(driver.cell->bel, port);
 
         std::vector<PipId> path;
-        RouteResult route_result = route_direct_net(
-                net, [&](PipId pip, WireId src_wire) { return global_pip_filter(pip, src); }, src, &path);
+        RouteResult route_result;
+        if (driver_is_mipi(driver)) {
+            route_result = route_direct_net(net, [&](PipId pip, WireId src_wire) { return true; }, src, &path);
+        } else {
+            route_result = route_direct_net(
+                    net, [&](PipId pip, WireId src_wire) { return global_pip_filter(pip, src); }, src, &path);
+        }
+
         if (route_result == NOT_ROUTED) {
             log_error("Can't route the %s network.\n", ctx->nameOf(net));
         }
@@ -557,6 +567,9 @@ struct GowinGlobalRouter
             hw_dhcen->setAttr(id_DHCEN_USED, 1);
             dhcen_ci->copyPortTo(id_CE, hw_dhcen, id_CE);
         }
+        if (driver_is_mipi(driver)) {
+            ctx->bindWire(src, net_before_dhcen, STRENGTH_LOCKED);
+        }
 
         // connect all users to upper level net
         std::vector<PortRef> users;

diff --git a/himbaechel/uarch/gowin/gowin.cc b/himbaechel/uarch/gowin/gowin.cc
@@ -1,5 +1,5 @@
-#include <regex>
 #include <map>
+#include <regex>
 
 #include "himbaechel_api.h"
 #include "himbaechel_helpers.h"
@@ -110,7 +110,8 @@ struct GowinArch : HimbaechelArch
 
     bool match_device(const std::string &device) override { return device.size() > 2 && device.substr(0, 2) == "GW"; }
 
-    std::unique_ptr<HimbaechelAPI> create(const std::string &device, const dict<std::string, std::string> &args) override
+    std::unique_ptr<HimbaechelAPI> create(const std::string &device,
+                                          const dict<std::string, std::string> &args) override
     {
         return std::make_unique<GowinImpl>();
     }
@@ -639,6 +640,9 @@ IdString GowinImpl::getBelBucketForCellType(IdString cell_type) const
     if (cell_type.in(id_IBUF, id_OBUF)) {
         return id_IOB;
     }
+    if (cell_type.in(id_MIPI_OBUF, id_MIPI_OBUF_A)) {
+        return id_MIPI_OBUF;
+    }
     if (type_is_lut(cell_type)) {
         return id_LUT4;
     }
@@ -676,6 +680,9 @@ bool GowinImpl::isValidBelForCellType(IdString cell_type, BelId bel) const
     if (bel_type == id_IOB) {
         return cell_type.in(id_IBUF, id_OBUF);
     }
+    if (bel_type == id_MIPI_OBUF) {
+        return cell_type.in(id_MIPI_OBUF, id_MIPI_OBUF_A);
+    }
     if (bel_type == id_LUT4) {
         return type_is_lut(cell_type);
     }

diff --git a/himbaechel/uarch/gowin/gowin.h b/himbaechel/uarch/gowin/gowin.h
@@ -32,6 +32,10 @@ inline bool type_is_diffio(IdString cell_type)
 }
 inline bool is_diffio(const CellInfo *cell) { return type_is_diffio(cell->type); }
 
+// MIPI
+inline bool type_is_mipi(IdString cell_type) { return cell_type.in(id_MIPI_OBUF, id_MIPI_OBUF_A, id_MIPI_IBUF); }
+inline bool is_mipi(const CellInfo *cell) { return type_is_mipi(cell->type); }
+
 // IOLOGIC input and output separately
 
 inline bool type_is_iologico(IdString cell_type)
@@ -199,6 +203,9 @@ enum
 
     EMCU_Z = 300,
 
+    MIPIOBUF_Z = 301,
+    MIPIIBUF_Z = 302,
+
     // The two least significant bits encode Z for 9-bit adders and
     // multipliers, if they are equal to 0, then we get Z of their common
     // 18-bit equivalent.

diff --git a/himbaechel/uarch/gowin/gowin_arch_gen.py b/himbaechel/uarch/gowin/gowin_arch_gen.py
@@ -55,9 +55,11 @@
 
 USERFLASH_Z = 298
 
-
 EMCU_Z      = 300
 
+MIPIOBUF_Z  = 301
+MIPIIBUF_Z  = 302
+
 DSP_Z          = 509
 
 DSP_0_Z        = 511 # DSP macro 0
@@ -580,6 +582,23 @@ def create_extra_funcs(tt: TileType, db: chipdb, x: int, y: int):
                         tt.add_bel_pin(bel, port, wire, PinType.OUTPUT)
                     else:
                         tt.add_bel_pin(bel, port, wire, PinType.INPUT)
+        elif func == 'mipi_obuf':
+            bel = tt.create_bel('MIPI_OBUF', 'MIPI_OBUF', MIPIOBUF_Z)
+        elif func == 'mipi_ibuf':
+            bel = tt.create_bel('MIPI_IBUF', 'MIPI_IBUF', MIPIIBUF_Z)
+            wire = desc['HSREN']
+            if not tt.has_wire(wire):
+                tt.create_wire(wire)
+            tt.add_bel_pin(bel, 'HSREN', wire, PinType.INPUT)
+            wire = 'MIPIOL'
+            if not tt.has_wire(wire):
+                tt.create_wire(wire)
+            tt.add_bel_pin(bel, 'OL', wire, PinType.OUTPUT)
+            for i in range(2):
+                wire = f'MIPIEN{i}'
+                if not tt.has_wire(wire):
+                    tt.create_wire(wire)
+                tt.add_bel_pin(bel, f'MIPIEN{i}', wire, PinType.INPUT)
         elif func == 'buf':
             for buf_type, wires in desc.items():
                 for i, wire in enumerate(wires):