Make the sed1520 driver work in 80-family connection style without requiring

an external inverter.

ChangeLog

@@ -21,6 +21,7 @@ v0.5dev (ongoing development)
  + glcd driver: new connection type 'glcd2usb'
  * lcdproc client: On FreeBSD show only unique processes in 'S' screen
  * picolcd: Use libusb-1.0 asynchronous transfers to fix missed keys (M. Jones)
+ * sed1520: Make it work without using an external inverter
 
 v0.5.5
  + sed1330 driver: Add support for HG25504 (L. Lagendijk)

LCDd.conf

@@ -1029,13 +1029,18 @@ Port=0x378
 # Select the interface type (wiring) for the display. Supported values are
 # 68 for 68-style connection (RESET level high) and 80 for 80-style connection
 # (RESET level low). [legal: 68, 80; default: 80]
-InterfaceType=68
+InterfaceType=80
 
 # On fast machines it may be necessary to slow down transfer to the display.
 # If this value is set to zero, delay is disabled. Any value greater than
 # zero slows down each write by one microsecond. [legal: 0-1000; default: 1]
 DelayMult=0
 
+# The original wiring used an inverter to drive the control lines. If you do
+# not use an inverter set haveInverter to off. [default: yes; legal: yes, no]
+haveInverter=no
+
+
 
 ## serial POS display driver ##
 [serialPOS]

docs/lcdproc-user/drivers/sed1520.docbook

@@ -48,11 +48,12 @@ without having a datasheet to check against!</para>
 <sect3 id="sed1520-80">
 <title>80-style connection style</title>
 
-<para>This mode of operation is selected if the RESET line is wired to ground.
+<para>This mode of operation is selected if the RESET line is wired to
-The wiring used by this driver in 80-style mode requires the use of an external
+ground. The wiring used by this driver in 80-style mode assumes you have
-74HC04 inverter and assumes you have /CS1 and /CS2 lines available (thus you
+/CS1 and /CS2 lines available (thus you must have an external clock
-must have an external clock generator) and toggles the /RW line. This is the
+generator) and toggles the /RW line. This is the original wiring by Robin Adams
-original wiring by Robin Adams.</para>
+(<ulink url="http://www.usblcd.de/lcdproc/sed1520.php4">SED1520 LPT Port</ulink>).
+</para>
 
 <table id="sed1520-connections-80-mapping">
 <title>SED1520 80-style wiring schematic</title>
@@ -214,14 +215,6 @@ line. Writing is controlled by toggling the E1 and E2 line while /RW is low.
 </tgroup>
 </table>
 
-<note>
-<para>This is the only wiring I was able to test. My display (Crystalfontz
-CFAG12232J-TFH-TA) has E1 and E2 lines. Trying to use it with 80-style wiring
-was not successful. I suspect that (as the E# line is used as /RD line in
-80-style mode) the wiring resulted in reading from one chip while writing to
-the other at the same time and the data bus got fuzzed.</para>
-</note>
-
 </sect3>
 
 </sect2>
@@ -257,10 +250,11 @@ the other at the same time and the data bus got fuzzed.</para>
     the level of the RESET line: 68-style MCU interface (high level) or
     80-style MCU interface (low level).
   </para><para>
-    Use value <literal>68</literal> if your display is connected 68-style
+    Use value <literal>68</literal> if your display is connected using
-    style. In this mode the E1 and E2 lines are cycled to write the data. If
+    &quot;68 family MPU&quot; style. In this mode E1 and E2 lines are cycled to
-    you use <literal>80</literal> (the default), 80-style style is selected
+    write the data. If you use <literal>80</literal> (the default),
-    and the /WR line is cycled and /CS1 and /CS2 lines are required.
+    &quot;80 family MPU&quot; style is selected and the /WR line is cycled and
+    /CS1 and /CS2 lines are required.
   </para></listitem>
 </varlistentry>
 
@@ -276,6 +270,16 @@ the other at the same time and the data bus got fuzzed.</para>
     lot, larger value should likely be avoided.
   </para></listitem>
 </varlistentry>
+
+<varlistentry>
+  <term>
+    <property>haveInverter</property> = &parameters.yesdefno;
+  </term>
+  <listitem><para>
+    The original wiring by Robin used an inverter to drive the control lines.
+    If you do not use an inverter set this to <literal>no</literal>.
+  </para></listitem>
+</varlistentry>
 </variablelist>
 
 </sect3>

server/drivers/sed1520.c

@@ -57,6 +57,7 @@ typedef struct sed1520_private_data {
     unsigned short port;
     int interface;
     int delayMult;
+    int haveInverter;
 
     unsigned char *framebuf;
 } PrivateData;
@@ -90,17 +91,31 @@ writecommand(PrivateData *p, int value, int chip)
     }
     else {
 	port_out(p->port, value);
-	/*
+	if (p->haveInverter) {
-	* lower WR, rise A0 and CS1 and/or CS2. Take bit inversion of parallel
+	    /*
-	* port into account. External inverter required!
+	     * lower WR, rise A0 and CS1 and/or CS2 taking bit inversion of
-	*/
+	     * parallel port into account. External inverter required!
-	port_out(p->port + 2, WR + CS1 - (chip & CS1) + (chip & CS2));
+	     */
-	/* rise WR */
+	    port_out(p->port + 2, WR + CS1 - (chip & CS1) + (chip & CS2));
-	port_out(p->port + 2, CS1 - (chip & CS1) + (chip & CS2));
+	    /* rise WR */
-	if (p->delayMult) uPause(p->delayMult);
+	    port_out(p->port + 2, CS1 - (chip & CS1) + (chip & CS2));
-	/* lower WR again */
+	    if (p->delayMult)
-	port_out(p->port + 2, WR + CS1 - (chip & CS1) + (chip & CS2));
+		uPause(p->delayMult);
-	if (p->delayMult) uPause(p->delayMult);
+	    /* lower WR again */
+	    port_out(p->port + 2, WR + CS1 - (chip & CS1) + (chip & CS2));
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	}
+	else {			/* No inverter connected */
+	    /* Note: CS?-(chip&CS?) drive the pin low if controller is set */
+	    port_out(p->port + 2, (WR + CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    port_out(p->port + 2, (CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	    port_out(p->port + 2, (WR + CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	}
     }
 }
 
@@ -123,12 +138,25 @@ writedata(PrivateData *p, int value, int chip)
     }
     else {
 	port_out(p->port, value);
-	/* lower WR and A0, rise CS1 and/or CS2. See also writecommand. */
+	if (p->haveInverter) {
-	port_out(p->port + 2, A0 + WR + CS1 - (chip & CS1) + (chip & CS2));
+	    /* lower WR and A0, rise CS1 and/or CS2. See also writecommand. */
-	port_out(p->port + 2, A0 + CS1 - (chip & CS1) + (chip & CS2));
+	    port_out(p->port + 2, A0 + WR + CS1 - (chip & CS1) + (chip & CS2));
-	if (p->delayMult) uPause(p->delayMult);
+	    port_out(p->port + 2, A0 + CS1 - (chip & CS1) + (chip & CS2));
-	port_out(p->port + 2, A0 + WR + CS1 - (chip & CS1) + (chip & CS2));
+	    if (p->delayMult)
-	if (p->delayMult) uPause(p->delayMult);
+		uPause(p->delayMult);
+	    port_out(p->port + 2, A0 + WR + CS1 - (chip & CS1) + (chip & CS2));
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	}
+	else {
+	    port_out(p->port + 2, (A0 + WR + CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    port_out(p->port + 2, (A0 + CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	    port_out(p->port + 2, (A0 + WR + CS1 - (chip & CS1) + CS2 - (chip & CS2)) ^ OUTMASK);
+	    if (p->delayMult)
+		uPause(p->delayMult);
+	}
     }
 }
 
@@ -255,6 +283,12 @@ sed1520_init(Driver * drvthis)
 	p->interface = 80;
     }
 
+    /*
+     * The original wiring used an inverter to drive the control lines. As
+     * someone may still be using this, the following setting in ON by default.
+     */
+    p->haveInverter = drvthis->config_get_bool(drvthis->name, "haveInverter", 0, 1);
+
     /* Initialize display */
     writecommand(p, SOFT_RESET, CS1 + CS2);
     writecommand(p, DISP_ON, CS1 + CS2);