From 6cfb56bb0712756ab65802721a43d0ad243043d8 Mon Sep 17 00:00:00 2001
From: stone3311 <fenstein12@googlemail.com>
Date: Wed, 28 Dec 2022 02:13:06 +0100
Subject: [PATCH] terasic_deca: add SPI SD card support

---
 litex_boards/platforms/terasic_deca.py | 18 ++++++++++++++++++
 litex_boards/targets/terasic_deca.py   | 23 ++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/litex_boards/platforms/terasic_deca.py b/litex_boards/platforms/terasic_deca.py
index 65f915f..be74bc6 100644
--- a/litex_boards/platforms/terasic_deca.py
+++ b/litex_boards/platforms/terasic_deca.py
@@ -174,6 +174,24 @@ _io = [
         IOStandard("1.5 V")
     ),
 
+    # SPI SDCard.
+    ("spisdcard", 0,
+        Subsignal("clk",    Pins("T20")),
+        Subsignal("cs_n",   Pins("R20")),
+        Subsignal("mosi",   Pins("T21")),
+        Subsignal("miso",   Pins("R18")),
+        IOStandard("1.5 V")
+    ),
+    ("spisdcard_aux", 0,
+        Subsignal("sel",      Pins("P13"), IOStandard("3.3-V LVTTL")),
+        Subsignal("cmd_dir",  Pins("U22")),
+        Subsignal("d0_dir",   Pins("T22")),
+        Subsignal("d123_dir", Pins("U21")),
+        Subsignal("dat1",     Pins("T18")),
+        Subsignal("dat2",     Pins("T19")),
+        IOStandard("1.5 V")
+    ),
+
     # MII Ethernet.
     ("eth_clocks", 0,
         Subsignal("tx", Pins("T5")),
diff --git a/litex_boards/targets/terasic_deca.py b/litex_boards/targets/terasic_deca.py
index cbb1161..4be19a5 100755
--- a/litex_boards/targets/terasic_deca.py
+++ b/litex_boards/targets/terasic_deca.py
@@ -61,6 +61,7 @@ class BaseSoC(SoCCore):
         with_uartbone       = False,
         with_jtagbone       = False,
         with_video_terminal = False,
+        with_spi_sdcard     = False,
         with_ethernet       = False,
         with_etherbone      = False,
         eth_ip              = "192.168.1.50",
@@ -90,7 +91,7 @@ class BaseSoC(SoCCore):
         # JTAGbone ---------------------------------------------------------------------------------
         if with_jtagbone:
             self.add_jtagbone()
-        
+
         # Ethernet ---------------------------------------------------------------------------------
         if with_ethernet or with_etherbone:
             self.platform.toolchain.additional_sdc_commands += [
@@ -113,6 +114,24 @@ class BaseSoC(SoCCore):
             self.videophy = VideoDVIPHY(platform.request("hdmi"), clock_domain="hdmi")
             self.add_video_terminal(phy=self.videophy, timings="800x600@60Hz", clock_domain="hdmi")
 
+        # SPI SD card ------------------------------------------------------------------------------
+        if with_spi_sdcard:
+            self.add_spi_sdcard()
+
+            sd_aux = self.platform.request("spisdcard_aux")
+
+            # Set the SD card supply to 3.3V
+            self.comb += sd_aux.sel.eq(0)
+
+            # Set the direction of the level shifter (0 = SD to FPGA; 1 = FPGA to SD)
+            self.comb += sd_aux.cmd_dir.eq(1)
+            self.comb += sd_aux.d0_dir.eq(0)
+            self.comb += sd_aux.d123_dir.eq(1)
+
+            # Keep the unused data lines high
+            self.comb += sd_aux.dat1.eq(1)
+            self.comb += sd_aux.dat2.eq(1)
+
         # Leds -------------------------------------------------------------------------------------
         if with_led_chaser:
             self.leds = LedChaser(
@@ -133,6 +152,7 @@ def main():
     parser.add_target_argument("--with-uartbone",       action="store_true",    help="Enable UARTbone support.")
     parser.add_target_argument("--with-jtagbone",       action="store_true",    help="Enable JTAGbone support.")
     parser.add_target_argument("--with-video-terminal", action="store_true",    help="Enable Video Terminal (VGA).")
+    parser.add_target_argument("--with-spi-sdcard",     action="store_true",    help="Enable SPI SD card controller.")
     args = parser.parse_args()
 
     soc = BaseSoC(
@@ -144,6 +164,7 @@ def main():
         with_uartbone       = args.with_uartbone,
         with_jtagbone       = args.with_jtagbone,
         with_video_terminal = args.with_video_terminal,
+        with_spi_sdcard     = args.with_spi_sdcard,
         **parser.soc_argdict
     )
     builder = Builder(soc, **parser.builder_argdict)