integration/soc/add_spi_flash: Add LiteSPI initial support (enabled when module is provided).

Test on iCEBreaker in 1X/4X mode for now. In the future, we could probably deprecate support
for old SPIFlash core.

litex/soc/integration/soc.py

@@ -1477,7 +1477,9 @@ class LiteXSoC(SoC):
             self.platform.add_false_path_constraints(self.crg.cd_sys.clk, eth_rx_clk, eth_tx_clk)
 
     # Add SPI Flash --------------------------------------------------------------------------------
-    def add_spi_flash(self, name="spiflash", mode="4x", dummy_cycles=None, clk_freq=None):
+    def add_spi_flash(self, name="spiflash", mode="4x", dummy_cycles=None, clk_freq=None, module=None, **kwargs):
+        # LiteX SPI Flash Core FIXME: Keep it for now but we'll probably deprecate it.
+        if module is None:
             # Imports.
             from litex.soc.cores.spi_flash import SpiFlash
 
@@ -1498,6 +1500,26 @@ class LiteXSoC(SoC):
             setattr(self.submodules, name, spiflash)
             spiflash_region = SoCRegion(origin=self.mem_map.get(name, None), size=0x1000000) # FIXME: Get size from SPI Flash
             self.bus.add_slave(name=name, slave=spiflash.bus, region=spiflash_region)
+        # LiteSPI.
+        else:
+            # Imports.
+            from litespi.phy.generic import LiteSPIPHY
+            from litespi import LiteSPI
+
+            # Checks/Parameters.
+            assert mode in ["1x", "4x"]
+            if clk_freq is None: clk_freq = self.sys_clk_freq
+
+            # Core.
+            self.check_if_exists(name + "_phy")
+            self.check_if_exists(name + "_mmap")
+            spiflash_pads   = self.platform.request(name if mode == "1x" else name + mode)
+            spiflash_phy    = LiteSPIPHY(spiflash_pads, module)
+            spiflash_mmap   = LiteSPI(spiflash_phy, clk_freq=clk_freq, mmap_endianness=self.cpu.endianness, **kwargs)
+            setattr(self.submodules, name + "_phy",  spiflash_phy)
+            setattr(self.submodules, name + "_mmap", spiflash_mmap)
+            spiflash_region = SoCRegion(origin=self.mem_map.get(name, None), size=module.total_size, cached=False)
+            self.bus.add_slave(name=name, slave=spiflash_mmap.bus, region=spiflash_region)
 
     # Add SPI SDCard -------------------------------------------------------------------------------
     def add_spi_sdcard(self, name="spisdcard", spi_clk_freq=400e3, software_debug=False):