This patchset has 2 parts, a bug-fix and a feature-add 01 pc87360-01-fix-vref-ext-int-mixup.patch fixes a 1-line bug in the internal vs external voltage reference selection, Old code used vrefint when vrefext was chosen, and vice versa. Henrik Brix Andersen, who also has this chip on his soekris 4801, has indicated this improved the accuracy of his readings. 02 pc87360-02-vref-options.patch *(RFC)* adds 3 new module-parameters, which allow the well-equipped user to improve the accuracy of her on-board voltage measurements. Im seeking input for whether any/all of these parameters are useful or excessive, and where any additional commentary should go - Ive not put it in the parameter-info, though that would be the most usable place for it; I dont know the norms for verbosity here, and Ive already added a 2nd line for each. The following comments could reasonably go into Docs, but if so, where - theres none currently, and it feels a bit presumptuous to create it anew. The 3 params, most usable 1st, are: +module_param(vrefext, int, 0); The PC87366 Spec recommends a that a voltage of 1.211 volts be fed to the external vref input, so the code matches that expectation, but your board may differ. If you measure your boards actual voltage, you can tell the driver aobout it. This param could be used to workaround the bug fixed by the 1st patch, and ironically, it is more verifiable without that bug fixed. +module_param(vrefscale, int, 0); If you *also* measure several of the other reported voltages, you can do some math (y=mx+b) to determine where your scaling factor is in the specified range; 2.45 V +/- 50 mV. This parameter is clamped to that range. +module_param(vrefint, int, 0); If youve tweaked both of the above, *and* have the ability to switch to an internal voltage reference, you can then do more math (y=mx+b) to determine what the internal voltage ref really is. [jimc at harpo pset-pc87360-vref]$ diffstat pc87360-0* V-1/drivers/hwmon/pc87360.c | 2 +- V-2/drivers/hwmon/pc87360.c | 30 +++++++++++++++++++++++++++++- 2 files changed, 30 insertions(+), 2 deletions(-) Signed-off-by: Jim Cromie <jim.cromie at gmail.com>
