From af909b43d540eae851462bc6a3d9e5bab26c1c2c Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Sat, 14 Nov 2015 21:00:42 +0100
Subject: [PATCH] soc/cores/uart: add UARTWishboneBridgeDriver software

---
 litex/soc/cores/uart/software/__init__.py |  0
 litex/soc/cores/uart/software/reg.py      | 56 +++++++++++++++++
 litex/soc/cores/uart/software/wishbone.py | 77 +++++++++++++++++++++++
 3 files changed, 133 insertions(+)
 create mode 100644 litex/soc/cores/uart/software/__init__.py
 create mode 100644 litex/soc/cores/uart/software/reg.py
 create mode 100644 litex/soc/cores/uart/software/wishbone.py

diff --git a/litex/soc/cores/uart/software/__init__.py b/litex/soc/cores/uart/software/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/litex/soc/cores/uart/software/reg.py b/litex/soc/cores/uart/software/reg.py
new file mode 100644
index 000000000..6f154fd75
--- /dev/null
+++ b/litex/soc/cores/uart/software/reg.py
@@ -0,0 +1,56 @@
+import csv
+
+# TODO: share reg for all software drivers
+
+class MappedReg:
+    def __init__(self, readfn, writefn, name, addr, length, busword, mode):
+        self.readfn = readfn
+        self.writefn = writefn
+        self.addr = addr
+        self.length = length
+        self.busword = busword
+        self.mode = mode
+
+    def read(self):
+        if self.mode not in ["rw", "ro"]:
+            raise KeyError(name + "register not readable")
+        datas = self.readfn(self.addr, burst_length=self.length)
+        if isinstance(datas, int):
+            return datas
+        else:
+            data = 0
+            for i in range(self.length):
+                data = data << self.busword
+                data |= datas[i]
+            return data
+
+    def write(self, value):
+        if self.mode not in ["rw", "wo"]:
+            raise KeyError(name + "register not writable")
+        datas = []
+        for i in range(self.length):
+            datas.append((value >> ((self.length-1-i)*self.busword)) & (2**self.busword-1))
+        self.writefn(self.addr, datas)
+
+
+class MappedRegs:
+    def __init__(self, d):
+        self.d = d
+
+    def __getattr__(self, attr):
+        try:
+            return self.__dict__['d'][attr]
+        except KeyError:
+            pass
+        raise KeyError("No such register " + attr)
+
+
+def build_map(addrmap, busword, readfn, writefn):
+    csv_reader = csv.reader(open(addrmap), delimiter=',', quotechar='#')
+    d = {}
+    for item in csv_reader:
+        name, addr, length, mode = item
+        addr = int(addr.replace("0x", ""), 16)
+        length = int(length)
+        d[name] = MappedReg(readfn, writefn, name, addr, length, busword, mode)
+    return MappedRegs(d)
diff --git a/litex/soc/cores/uart/software/wishbone.py b/litex/soc/cores/uart/software/wishbone.py
new file mode 100644
index 000000000..82723adb4
--- /dev/null
+++ b/litex/soc/cores/uart/software/wishbone.py
@@ -0,0 +1,77 @@
+import serial
+from struct import *
+
+# TODO: share reg for all software drivers
+from litex.soc.cores.uart.software.reg import *
+
+
+def write_b(uart, data):
+    uart.write(pack('B', data))
+
+
+class UARTWishboneBridgeDriver:
+    cmds = {
+        "write": 0x01,
+        "read":  0x02
+    }
+    def __init__(self, port, baudrate=115200, addrmap=None, busword=8, debug=False):
+        self.port = port
+        self.baudrate = str(baudrate)
+        self.debug = debug
+        self.uart = serial.Serial(port, baudrate, timeout=0.25)
+        if addrmap is not None:
+            self.regs = build_map(addrmap, busword, self.read, self.write)
+
+    def open(self):
+        self.uart.flushOutput()
+        self.uart.close()
+        self.uart.open()
+        self.uart.flushInput()
+
+    def close(self):
+        self.uart.flushOutput()
+        self.uart.close()
+
+    def read(self, addr, burst_length=1):
+        datas = []
+        self.uart.flushInput()
+        write_b(self.uart, self.cmds["read"])
+        write_b(self.uart, burst_length)
+        word_addr = addr//4
+        write_b(self.uart, (word_addr >> 24) & 0xff)
+        write_b(self.uart, (word_addr >> 16) & 0xff)
+        write_b(self.uart, (word_addr >>  8) & 0xff)
+        write_b(self.uart, (word_addr >>  0) & 0xff)
+        for i in range(burst_length):
+            data = 0
+            for k in range(4):
+                data = data << 8
+                data |= ord(self.uart.read())
+            if self.debug:
+                print("RD {:08X} @ {:08X}".format(data, addr + 4*i))
+            datas.append(data)
+        if burst_length == 1:
+            return datas[0]
+        else:
+            return datas
+
+    def write(self, addr, data):
+        if isinstance(data, list):
+            burst_length = len(data)
+        else:
+            burst_length = 1
+            data = [data]
+        write_b(self.uart, self.cmds["write"])
+        write_b(self.uart, burst_length)
+        word_addr = addr//4
+        write_b(self.uart, (word_addr >> 24) & 0xff)
+        write_b(self.uart, (word_addr >> 16) & 0xff)
+        write_b(self.uart, (word_addr >>  8) & 0xff)
+        write_b(self.uart, (word_addr >>  0) & 0xff)
+        for i in range(len(data)):
+            dat = data[i]
+            for j in range(4):
+                write_b(self.uart, (dat >> 24) & 0xff)
+                dat = dat << 8
+            if self.debug:
+                print("WR {:08X} @ {:08X}".format(data[i], addr + 4*i))