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DTT: Issue one-shot command on AD7414 (LM75 code) to read temp

PATCH New Stefan Roese 3 participants 4 messages May 16, 2008 – Jun 4, 2008 Hardware monitoring

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#0 lore raw

PATCH 1/1 DTT: Issue one-shot command on AD7414 (LM75 code) to read temp

On AD7414 the first value upon bootup is not read correctly. This is most likely because of the 800ms update time of the temp register in normal update mode. To get current values each time we issue the "dtt" command including upon powerup we switch into one-short mode.

This patch fixes the problem on AD7414 equipped boards (Sequoia, Canyonlands etc), that temp value printed in the bootup log was incorrect.

---
 drivers/hwmon/lm75.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
drivers/hwmon/lm75.c +13 -0
index e29b294..c348517 100644
@@ -47,6 +47,19 @@ int dtt_read(int sensor, int reg)
     int dlen;
     uchar data[2];
 
+#ifdef CONFIG_DTT_AD7414
+    /*
+     * On AD7414 the first value upon bootup is not read correctly.
+     * This is most likely because of the 800ms update time of the
+     * temp register in normal update mode. To get current values
+     * each time we issue the "dtt" command including upon powerup
+     * we switch into one-short mode.
+     *
+     * Issue one-shot mode command
+     */
+    dtt_write(sensor, DTT_CONFIG, 0x64);
+#endif
+
     /*
      * Validate 'reg' param
      */
Signature · 1 line
1.5.5.1
#1 lore raw

PATCH 1/1 DTT: Issue one-shot command on AD7414 (LM75 code) to read temp

Hi Stefan,

Quoted 2 lines

To get current values each time we issue the "dtt" command including upon powerup we switch into one-short mode.

If we are in "one-short" mode, shouldn't we add 1 before the printout?

Sorry, couldn't resist ;)

Cheers
Detlev

Signature · 5 lines
error compiling committee.c: too many arguments to function
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de
#2 lore raw

PATCH 1/1 DTT: Issue one-shot command on AD7414 (LM75 code) to read temp

Quoted 4 lines · Detlev Zundel
Quoted 2 lines

To get current values each time we issue the "dtt" command including upon powerup we switch into one-short mode.

If we are in "one-short" mode, shouldn't we add 1 before the printout?

I had to read your mail twice before noticing my error.

Quoted 1 line

Sorry, couldn't resist ;)

Nice one. ;)

Best regards,
Stefan

=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================

#3 lore raw

PATCH 1/1 DTT: Issue one-shot command on AD7414 (LM75 code) to read temp

In reply to Stefan Roese
Quoted 6 lines · In message <[email protected]> you wrote:

On AD7414 the first value upon bootup is not read correctly. This is most likely because of the 800ms update time of the temp register in normal update mode. To get current values each time we issue the "dtt" command including upon powerup we switch into one-short mode.

Quoted 8 lines

This patch fixes the problem on AD7414 equipped boards (Sequoia, Canyonlands etc), that temp value printed in the bootup log was incorrect.

---
 drivers/hwmon/lm75.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

Applied, thanks.

Best regards,

Wolfgang Denk

Signature · 5 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Real computer scientists don't comment their  code.  The  identifiers
are so long they can't afford the disk space.