diff options
Diffstat (limited to 'Documentation/hwmon/nsa320')
| -rw-r--r-- | Documentation/hwmon/nsa320 | 53 |
1 files changed, 0 insertions, 53 deletions
diff --git a/Documentation/hwmon/nsa320 b/Documentation/hwmon/nsa320 deleted file mode 100644 index fdbd6947799b..000000000000 --- a/Documentation/hwmon/nsa320 +++ /dev/null @@ -1,53 +0,0 @@ -Kernel driver nsa320_hwmon -========================== - -Supported chips: - * Holtek HT46R065 microcontroller with onboard firmware that configures - it to act as a hardware monitor. - Prefix: 'nsa320' - Addresses scanned: none - Datasheet: Not available, driver was reverse engineered based upon the - Zyxel kernel source - -Author: - Adam Baker <linux@baker-net.org.uk> - -Description ------------ - -This chip is known to be used in the Zyxel NSA320 and NSA325 NAS Units and -also in some variants of the NSA310 but the driver has only been tested -on the NSA320. In all of these devices it is connected to the same 3 GPIO -lines which are used to provide chip select, clock and data lines. The -interface behaves similarly to SPI but at much lower speeds than are normally -used for SPI. - -Following each chip select pulse the chip will generate a single 32 bit word -that contains 0x55 as a marker to indicate that data is being read correctly, -followed by an 8 bit fan speed in 100s of RPM and a 16 bit temperature in -tenths of a degree. - - -sysfs-Interface ---------------- - -temp1_input - temperature input -fan1_input - fan speed - -Notes ------ - -The access timings used in the driver are the same as used in the Zyxel -provided kernel. Testing has shown that if the delay between chip select and -the first clock pulse is reduced from 100 ms to just under 10ms then the chip -will not produce any output. If the duration of either phase of the clock -is reduced from 100 us to less than 15 us then data pulses are likely to be -read twice corrupting the output. The above analysis is based upon a sample -of one unit but suggests that the Zyxel provided delay values include a -reasonable tolerance. - -The driver incorporates a limit that it will not check for updated values -faster than once a second. This is because the hardware takes a relatively long -time to read the data from the device and when it does it reads both temp and -fan speed. As the most likely case for two accesses in quick succession is -to read both of these values avoiding a second read delay is desirable. |