[U-Boot-Users] [PATCH] 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.
Signed-off-by: Stefan Roese sr@denx.de --- drivers/hwmon/lm75.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index e29b294..c348517 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -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 */
Hi Stefan,
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
On Monday 19 May 2008, Detlev Zundel wrote:
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.
Sorry, couldn't resist ;)
Nice one. ;)
Best regards, Stefan
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In message 1210928766-31604-1-git-send-email-sr@denx.de 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.
This patch fixes the problem on AD7414 equipped boards (Sequoia, Canyonlands etc), that temp value printed in the bootup log was incorrect.
Signed-off-by: Stefan Roese sr@denx.de
drivers/hwmon/lm75.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-)
Applied, thanks.
Best regards,
Wolfgang Denk
participants (3)
-
Detlev Zundel -
Stefan Roese -
Wolfgang Denk