Hello Doug and Kukjin, On 26 June 2014 21:16, Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > Naveen, > > On Thu, Jun 26, 2014 at 5:19 AM, Naveen Krishna Chatradhi > <ch.naveen@xxxxxxxxxxx> wrote: >> Exynos5250 based Snow board has 4 NTC thermistors to measure >> temperatures at various points on the board. >> >> IIO based ADC becomes the parent and NTC thermistors are the childs, >> via the HWMON interface. >> >> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> >> --- >> Posted earlier by Doug Anderson @ https://lkml.org/lkml/2013/3/27/453 >> >> This patch depends on (1/4 and 2/4 patches of) patchset posted >> http://www.spinics.net/lists/linux-iio/msg13486.html >> Which were applied on to Guenter Roeck's tree. >> >> cat sysfs entries exported by hwmon for 4 thermistors >> and verified the values on Snow. >> >> arch/arm/boot/dts/exynos5250-snow.dts | 34 +++++++++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) > > NAK. > > The first chunk of exynos5250-snow devices have the thermistors > populated, but a huge chunk of devices also _don't_ have them > populated. I've realized only the rev4 and before boards have thermistors while going through the git logs of snow related dts files in an older chrome kernel. > > If I remember my history properly, rev3 and earlier all had > thermistors. Some of rev4 might have thermistors (I never got a clear > answer). ...and rev5 definitely doesn't have resistors. Aside from > thermistors there's no good reason to differentiate rev3 and rev4 > (they just have different memory). The upstream kernel may eventually > need to differentiate rev4 and rev5 since they have a different audio > codec. I've found one patch which says, "No thermistors on Rev5 and above boards" I still thought, we should support few boards out there. But, i din't knew they were removed completely. > > See <https://chromium-review.googlesource.com/#/c/170841/> for some > descriptions of the different revisions of snow and how they were > handled in the Chrome OS tree. Got it now, Thanks > > See <https://chromium-review.googlesource.com/#/c/186357/> for > thermistors talk. Patch set #1 actually split out rev3, but we then > decided that we really didn't need to use the thermistors on any of > the revisions so the later patchsets just totally take them out. So, no need of thermistor nodes on Snow. I thought https://lkml.org/lkml/2013/3/27/453 patch is missed out. > > -Doug Kukjin, Sorry for the confusion. Please drop this one. -- Thanks, (: Nav :) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
