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8b6f5e0f19
Murata Manufacturing Co., Ltd is the vendor for NTC (Negative Temperature coefficient) based Thermistors. But, the driver extensively uses "NTC" as the vendor name. This patch corrects the vendor name also updates the compatibility strings according to the vendor-prefix.txt Note: Drivers continue to support the previous compatible strings but further addition of these compatible strings in device tree is deprecated. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
94 lines
2.4 KiB
Plaintext
94 lines
2.4 KiB
Plaintext
Kernel driver ntc_thermistor
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=================
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Supported thermistors from Murata:
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* Murata NTC Thermistors NCP15WB473, NCP18WB473, NCP21WB473, NCP03WB473, NCP15WL333
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Prefixes: 'ncp15wb473', 'ncp18wb473', 'ncp21wb473', 'ncp03wb473', 'ncp15wl333'
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Datasheet: Publicly available at Murata
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Other NTC thermistors can be supported simply by adding compensation
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tables; e.g., NCP15WL333 support is added by the table ncpXXwl333.
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Authors:
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MyungJoo Ham <myungjoo.ham@samsung.com>
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Description
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-----------
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The NTC (Negative Temperature Coefficient) thermistor is a simple thermistor
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that requires users to provide the resistance and lookup the corresponding
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compensation table to get the temperature input.
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The NTC driver provides lookup tables with a linear approximation function
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and four circuit models with an option not to use any of the four models.
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The four circuit models provided are:
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$: resister, [TH]: the thermistor
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1. connect = NTC_CONNECTED_POSITIVE, pullup_ohm > 0
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[pullup_uV]
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[TH] $ (pullup_ohm)
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+----+-----------------------[read_uV]
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$ (pulldown_ohm)
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--- (ground)
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2. connect = NTC_CONNECTED_POSITIVE, pullup_ohm = 0 (not-connected)
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[pullup_uV]
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[TH]
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+----------------------------[read_uV]
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$ (pulldown_ohm)
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--- (ground)
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3. connect = NTC_CONNECTED_GROUND, pulldown_ohm > 0
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[pullup_uV]
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$ (pullup_ohm)
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+----+-----------------------[read_uV]
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[TH] $ (pulldown_ohm)
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-------- (ground)
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4. connect = NTC_CONNECTED_GROUND, pulldown_ohm = 0 (not-connected)
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[pullup_uV]
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$ (pullup_ohm)
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+----------------------------[read_uV]
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[TH]
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--- (ground)
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When one of the four circuit models is used, read_uV, pullup_uV, pullup_ohm,
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pulldown_ohm, and connect should be provided. When none of the four models
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are suitable or the user can get the resistance directly, the user should
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provide read_ohm and _not_ provide the others.
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Sysfs Interface
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---------------
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name the mandatory global attribute, the thermistor name.
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temp1_type always 4 (thermistor)
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RO
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temp1_input measure the temperature and provide the measured value.
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(reading this file initiates the reading procedure.)
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RO
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Note that each NTC thermistor has only _one_ thermistor; thus, only temp1 exists.
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