linux/Documentation/devicetree/bindings/hwmon/jc42.txt
Peter Rosin 68615eb01f hwmon: (jc42) optionally try to disable the SMBUS timeout
With a nxp,se97 chip on an atmel sama5d31 board, the I2C adapter driver
is not always capable of avoiding the 25-35 ms timeout as specified by
the SMBUS protocol. This may cause silent corruption of the last bit of
any transfer, e.g. a one is read instead of a zero if the sensor chip
times out. This also affects the eeprom half of the nxp-se97 chip, where
this silent corruption was originally noticed. Other I2C adapters probably
suffer similar issues, e.g. bit-banging comes to mind as risky...

The SMBUS register in the nxp chip is not a standard Jedec register, but
it is not special to the nxp chips either, at least the atmel chips
have the same mechanism. Therefore, do not special case this on the
manufacturer, it is opt-in via the device property anyway.

Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-11-30 13:12:44 -08:00

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Properties for Jedec JC-42.4 compatible temperature sensors
Required properties:
- compatible: May include a device-specific string consisting of the
manufacturer and the name of the chip. A list of supported
chip names follows.
Must include "jedec,jc-42.4-temp" for any Jedec JC-42.4
compatible temperature sensor.
Supported chip names:
adi,adt7408
atmel,at30ts00
atmel,at30tse004
onnn,cat6095
onnn,cat34ts02
maxim,max6604
microchip,mcp9804
microchip,mcp9805
microchip,mcp9808
microchip,mcp98243
microchip,mcp98244
microchip,mcp9843
nxp,se97
nxp,se98
st,stts2002
st,stts2004
st,stts3000
st,stts424
st,stts424e
idt,tse2002
idt,tse2004
idt,ts3000
idt,ts3001
- reg: I2C address
Optional properties:
- smbus-timeout-disable: When set, the smbus timeout function will be disabled.
This is not supported on all chips.
Example:
temp-sensor@1a {
compatible = "jedec,jc-42.4-temp";
reg = <0x1a>;
};