From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Sat, 2 May 2015 13:25:40 +0000 (+0200)
Subject: liteusb/software/wishbone: optimize writes/reads (send a single packet for a command)
X-Git-Tag: 24jan2021_ls180~2269
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ff51bde7f061b690e435ecda375fb81aef968dae;p=litex.git

liteusb/software/wishbone: optimize writes/reads (send a single packet for a command)
---

diff --git a/misoclib/com/liteusb/software/ftdi/__init__.py b/misoclib/com/liteusb/software/ftdi/__init__.py
index a9327fe1..17e60b40 100644
--- a/misoclib/com/liteusb/software/ftdi/__init__.py
+++ b/misoclib/com/liteusb/software/ftdi/__init__.py
@@ -195,8 +195,18 @@ class UART:
             return -1
         return resp
 
-    def do_write(self, value):
-        msg = [0x5A, 0xA5, 0x5A, 0xA5, self.tag, 0x00, 0x00, 0x00, 1, value&0xFF]
+    def do_write(self, data):
+        if isinstance(data, int):
+            data = [data]
+        msg = [0x5A, 0xA5, 0x5A, 0xA5]
+        msg.append(self.tag)
+        length = len(data)
+        msg.append((length >> 24) & 0xff)
+        msg.append((length >> 16) & 0xff)
+        msg.append((length >> 8) & 0xff)
+        msg.append((length >> 0) & 0xff)
+        for value in data:
+            msg.append(value&0xff)
         self.service.write(bytes(msg))
 
 
@@ -339,8 +349,8 @@ class FTDIComDevice:
     def uartread(self, timeout=None):
         return self.uart.do_read(timeout)
 
-    def uartwrite(self, value):
-        return self.uart.do_write(value)
+    def uartwrite(self, data):
+        return self.uart.do_write(data)
 
     def dmaread(self):
         return self.dma.do_read()
diff --git a/misoclib/com/liteusb/software/wishbone.py b/misoclib/com/liteusb/software/wishbone.py
index a1a1a637..d8972740 100644
--- a/misoclib/com/liteusb/software/wishbone.py
+++ b/misoclib/com/liteusb/software/wishbone.py
@@ -24,17 +24,18 @@ class LiteUSBWishboneDriverFTDI:
     def close(self):
         self.com.close()
 
-    # XXX regroup cmds in a single packet
     def read(self, addr, burst_length=1):
         datas = []
+        msg = []
         self.com.uartflush()
-        self.com.uartwrite(self.cmds["read"])
-        self.com.uartwrite(burst_length)
+        msg.append(self.cmds["read"])
+        msg.append(burst_length)
         word_addr = addr//4
-        self.com.uartwrite((word_addr >> 24) & 0xff)
-        self.com.uartwrite((word_addr >> 16) & 0xff)
-        self.com.uartwrite((word_addr >> 8) & 0xff)
-        self.com.uartwrite((word_addr >> 0) & 0xff)
+        msg.append((word_addr >> 24) & 0xff)
+        msg.append((word_addr >> 16) & 0xff)
+        msg.append((word_addr >> 8) & 0xff)
+        msg.append((word_addr >> 0) & 0xff)
+        self.com.uartwrite(msg)
         for i in range(burst_length):
             data = 0
             for k in range(4):
@@ -48,27 +49,28 @@ class LiteUSBWishboneDriverFTDI:
         else:
             return datas
 
-    # XXX regroup cmds in a single packet
     def write(self, addr, data):
         if isinstance(data, list):
             burst_length = len(data)
         else:
             burst_length = 1
             data = [data]
-        self.com.uartwrite(self.cmds["write"])
-        self.com.uartwrite(burst_length)
+        msg = []
+        msg.append(self.cmds["write"])
+        msg.append(burst_length)
         word_addr = addr//4
-        self.com.uartwrite((word_addr >> 24) & 0xff)
-        self.com.uartwrite((word_addr >> 16) & 0xff)
-        self.com.uartwrite((word_addr >> 8) & 0xff)
-        self.com.uartwrite((word_addr >> 0) & 0xff)
+        msg.append((word_addr >> 24) & 0xff)
+        msg.append((word_addr >> 16) & 0xff)
+        msg.append((word_addr >> 8) & 0xff)
+        msg.append((word_addr >> 0) & 0xff)
         for i in range(len(data)):
             dat = data[i]
             for j in range(4):
-                self.com.uartwrite((dat >> 24) & 0xff)
+                msg.append((dat >> 24) & 0xff)
                 dat = dat << 8
             if self.debug:
                 print("WR {:08X} @ {:08X}".format(data[i], addr + 4*i))
+        self.com.uartwrite(msg)
 
 
 def LiteUSBWishboneDriver(chip="ft2232h", *args, **kwargs):