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<div class=Section1 style='layout-grid:15.6pt'>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Dear All,<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
I am writing one kernel driver which calls the standard parport interfaces to
drive LCD and its keyboard.<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>I have two modules used in
two different boards; the two modules are uss720.o and parport_pc.o.<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>The following is steps what
I do:<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>{<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1;
layout-grid-mode:char'><![if !supportLists]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><span style='mso-list:
Ignore'>1><font size=1 face="Times New Roman"><span style='font:7.0pt "Times New Roman"'>
</span></font></span></span></font><![endif]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Find the port by
parport_enumerate.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>struct
parport * port;<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'> for
(port = parport_enumerate (); port != NULL; port = port->next) <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>{<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>
//printk("paport base : %x ",(int)port->base);<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>
g_port = port; // g_port is one struct parport *<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>
break;<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;layout-grid-mode:char'><font
size=1 face=Arial><span lang=EN-US style='font-size:9.0pt;font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1;
layout-grid-mode:char'><![if !supportLists]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><span style='mso-list:
Ignore'>2><font size=1 face="Times New Roman"><span style='font:7.0pt "Times New Roman"'>
</span></font></span></span></font><![endif]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Write data:<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
ub[0] = uAddr; <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
g_port->ops->epp_write_addr(g_port, ub, 1, 0); <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
ub[0] = uval; <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
g_port->ops->epp_write_data(g_port, ub, 1, 0);<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1;
layout-grid-mode:char'><![if !supportLists]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><span style='mso-list:
Ignore'>3><font size=1 face="Times New Roman"><span style='font:7.0pt "Times New Roman"'>
</span></font></span></span></font><![endif]><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Read Data<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
ub[0] = uAddr; <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
g_port->ops->epp_write_addr(g_port, ub, 1, 0); <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
g_port->ops->epp_read_data(g_port, ub, 1, 0); <o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>
v = ub[0];<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>The above steps are able
to work for parport_pc.o, but panic for uss720.o.<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>I try to find what’s the
problem, and I find panic issue disappears after I call
“port->ops->data_reverse(port);”<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'> But it still doesn’t
work until I call “port->ops->write_control(port, 0x0);”.<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Could you like to explain
why I need call the two interfaces additionally for uss720.o?<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Thanks a lot,<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>Jet<o:p></o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='layout-grid-mode:char'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
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