Re: [linux-sunxi] Re: [PATCH][RFC] Add standalone driver for the A20 Soc TP embedded temperature sensor
thomas.kai...@phg-online.de wrote: In the meantime I realized that it's bit 7 of the touchpanel's TP_CTRL1 register so when sunxi-dbgreg.ko is loaded I should succeed with echo 'f1c25004' /sys/devices/virtual/misc/sunxi-dbgreg/rw/read; Corentin's code in this module as well as the sunxi-dbgreg-workaround I use set bit 4 to 1 but leave bit 7 untouched. Just realized my mistake. The method I used (writing \x10 to TP_CTRL1 using sunxi-dbgreg.ko) led to bit 7 being cleared and therefore setting CHOP_TEMP_EN from enable to disable. Restoring the default by writing \x90 to TP_CTRL1 gives temperature readouts way closer to reality. If CHOP_TEMP_EN is disabled the temperatures reported show in some situations a rather large offset to the actual temperatures in one or the other direction. If CHOP_TEMP_EN is enabled the deviation is much smaller. -- You received this message because you are subscribed to the Google Groups linux-sunxi group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[linux-sunxi] Re: [PATCH][RFC] Add standalone driver for the A20 Soc TP embedded temperature sensor
clabbe.montjoie wrote: For the temperature value, I cannot found any document on how to transform the raw value in °C. [...] Under heavy loads, the temperature of both sensors rise linearly. But based on a series of tests with and without heatsinks applied to the A20 I came to the conclusion that the values reported here must be already pre-calibrated. The base idle temperatures reported without an applied heatsink are way higher compared to the value of the very same A20 with heatsink: http://forum.lemaker.org/forum.php?mod=redirectgoto=findpostptid=8137pid=40817 Does anyone have a clue how the A20's CHOP_TEMP_EN register (according to the A20's user manual: Chop temperature calibration enable: 0: Disable, 1: Enable) can be read/set? -- You received this message because you are subscribed to the Google Groups linux-sunxi group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [linux-sunxi] Re: [PATCH][RFC] Add standalone driver for the A20 Soc TP embedded temperature sensor
Am 05.11.2014 12:44 schrieb thomas.kai...@phg-online.de: clabbe.montjoie wrote: For the temperature value, I cannot found any document on how to transform the raw value in °C. [...] Under heavy loads, the temperature of both sensors rise linearly. But based on a series of tests with and without heatsinks applied to the A20 I came to the conclusion that the values reported here must be already pre-calibrated. The base idle temperatures reported without an applied heatsink are way higher compared to the value of the very same A20 with heatsink: http://forum.lemaker.org/forum.php?mod=redirectgoto=findpostptid=8137pid=40817 Does anyone have a clue how the A20's CHOP_TEMP_EN register (according to the A20's user manual: Chop temperature calibration enable: 0: Disable, 1: Enable) can be read/set? For read write access from user space you can try to use devmem2 with the address given in the user manual. http://manpages.ubuntu.com/manpages/natty/man1/devmem2.1.html Regards, Christian -- You received this message because you are subscribed to the Google Groups linux-sunxi group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups linux-sunxi group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
