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<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi Johann,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>You’re right about it being missing.
I have another patch for virtex specific initialization that handles that. I
have not submitted it yet as I was trying to get these patches thru the system.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I have been told in this forum that the
bootstrap loader should not be setting up the baud rate and that normally the
boot loader does it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>In the case of FPGAs, we don’t
always use a boot loader so we need this to happen in the bootstrap loader. I
can forward that patch to you if you’re interested before it goes to this
group.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>John<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Johann Baudy
[mailto:johaahn@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, April 03, 2008
7:23 AM<br>
<b><span style='font-weight:bold'>To:</span></b> John Linn<br>
<b><span style='font-weight:bold'>Cc:</span></b> linuxppc-dev@ozlabs.org;
grant.likely@secretlab.ca<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [PATCH
3/3][POWERPC][V2] Xilinx: boot support for Xilinx uart 16550.</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Hi John,<br>
<br>
I've a small question about ns16550 boot support.<br>
I can't see any code related to either "clock-frequency" or
"current-speed" key words.<br>
Such actions are performed in of_serial.c to get appropriate baud rate (update
of UART_DLL and UART_DLM).<br>
<br>
Is it needed or is it a misunderstanding? <br>
Personally, I have added this below debug code (dirty :)) to make it work.<br>
<br>
diff --git a/arch/powerpc/boot/ns16550.c b/arch/powerpc/boot/ns16550.c<br>
index f8f1b2f..850e223 100644<br>
--- a/arch/powerpc/boot/ns16550.c<br>
+++ b/arch/powerpc/boot/ns16550.c<br>
@@ -26,6 +26,9 @@<br>
#define UART_MSR 6 /* In: Modem
Status Register */<br>
#define UART_SCR 7 /* I/O: Scratch
Register */<br>
<br>
+#define UART_LCR_DLAB 0x80 /* Divisor latch
access */<br>
+#define UART_LCR_8_DATA_BITS 0x03<br>
+<br>
static unsigned char *reg_base;<br>
static u32 reg_shift;<br>
<br>
@@ -56,6 +59,10 @@ int ns16550_console_init(void *devp, struct
serial_console_data *scdp)<br>
{<br>
int n;<br>
unsigned long reg_phys;<br>
+ unsigned long divisor=0;<br>
+ unsigned long spd=0, clk=0;<br>
+<br>
+<br>
<br>
n = getprop(devp, "virtual-reg",
&reg_base, sizeof(reg_base));<br>
if (n != sizeof(reg_base)) {<br>
@@ -75,5 +82,23 @@ int ns16550_console_init(void *devp, struct
serial_console_data *scdp)<br>
scdp->tstc = ns16550_tstc;<br>
scdp->close = NULL;<br>
<br>
+ n = getprop(devp, "current-speed", &spd,
sizeof(spd));<br>
+<br>
+<br>
+ n = getprop(devp, "clock-frequency", &clk,
sizeof(clk));<br>
+<br>
+<br>
+ if(spd&&clk)<br>
+ {<br>
+<br>
+ divisor = clk / (spd * 16UL);<br>
+<br>
+ out_8(reg_base + (UART_FCR << reg_shift),
0x06);<br>
+ out_8(reg_base + (UART_LCR << reg_shift),
UART_LCR_8_DATA_BITS|UART_LCR_DLAB);<br>
+ out_8(reg_base + (UART_DLL << reg_shift),
divisor&0xff);<br>
+ out_8(reg_base + (UART_DLM << reg_shift),
(divisor>>8)&0xff);<br>
+ out_8(reg_base + (UART_LCR << reg_shift),
UART_LCR_8_DATA_BITS);<br>
+<br>
+ }<br>
return 0;<br>
<br>
Best regards,<br>
Johann<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>On Wed, Apr 2, 2008 at 4:52 PM, John Linn <<a
href="mailto:john.linn@xilinx.com">john.linn@xilinx.com</a>> wrote:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>The Xilinx 16550 uart core is not a standard 16550 because it uses<br>
word-based addressing rather than byte-based adressing. With<br>
additional properties it is compatible with the open firmware<br>
'ns16550' compatible binding.<br>
<br>
This code updates the ns16550 driver to use the reg-offset property<br>
so that the Xilinx UART 16550 can be used with it. The reg-shift<br>
was already being handled.<br>
<br>
Signed-off-by: John Linn <<a href="mailto:john.linn@xilinx.com">john.linn@xilinx.com</a>><br>
---<br>
arch/powerpc/boot/ns16550.c | 5 +++++<br>
1 files changed, 5 insertions(+), 0 deletions(-)<br>
<br>
diff --git a/arch/powerpc/boot/ns16550.c b/arch/powerpc/boot/ns16550.c<br>
index f8f1b2f..da9d2c2 100644<br>
--- a/arch/powerpc/boot/ns16550.c<br>
+++ b/arch/powerpc/boot/ns16550.c<br>
@@ -56,6 +56,7 @@ int ns16550_console_init(void *devp, struct
serial_console_data *scdp)<br>
{<br>
int n;<br>
unsigned long reg_phys;<br>
+ u32 reg_offset;<br>
<br>
n = getprop(devp, "virtual-reg",
&reg_base, sizeof(reg_base));<br>
if (n != sizeof(reg_base)) {<br>
@@ -65,6 +66,10 @@ int ns16550_console_init(void *devp, struct serial_console_data
*scdp)<br>
reg_base = (void
*)reg_phys;<br>
}<br>
<br>
+ n = getprop(devp, "reg-offset",
&reg_offset, sizeof(reg_offset));<br>
+ if (n == sizeof(reg_offset))<br>
+ reg_base += reg_offset;<br>
+<br>
n = getprop(devp, "reg-shift", &reg_shift,
sizeof(reg_shift));<br>
if (n != sizeof(reg_shift))<br>
reg_shift = 0;<br>
--<br>
<a href="http://1.5.2.1" target="_blank">1.5.2.1</a><br>
<br>
<br>
<br>
_______________________________________________<br>
Linuxppc-dev mailing list<br>
<a href="mailto:Linuxppc-dev@ozlabs.org">Linuxppc-dev@ozlabs.org</a><br>
<a href="https://ozlabs.org/mailman/listinfo/linuxppc-dev" target="_blank">https://ozlabs.org/mailman/listinfo/linuxppc-dev</a><o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br clear=all>
<br>
-- <br>
Johann Baudy<br>
<a href="mailto:johaahn@gmail.com">johaahn@gmail.com</a> <o:p></o:p></span></font></p>
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