mirror of https://gitee.com/openkylin/linux.git
739 lines
20 KiB
C
739 lines
20 KiB
C
/*
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* ntc_thermistor.c - NTC Thermistors
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*
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* Copyright (C) 2010 Samsung Electronics
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* MyungJoo Ham <myungjoo.ham@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/pm_runtime.h>
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#include <linux/math64.h>
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#include <linux/platform_device.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_data/ntc_thermistor.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/machine.h>
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#include <linux/iio/driver.h>
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#include <linux/iio/consumer.h>
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#include <linux/hwmon.h>
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struct ntc_compensation {
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int temp_c;
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unsigned int ohm;
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};
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/*
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* Used as index in a zero-terminated array, holes not allowed so
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* that NTC_LAST is the first empty array entry.
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*/
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enum {
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NTC_B57330V2103,
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NTC_B57891S0103,
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NTC_NCP03WB473,
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NTC_NCP03WF104,
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NTC_NCP15WB473,
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NTC_NCP15WL333,
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NTC_NCP15XH103,
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NTC_NCP18WB473,
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NTC_NCP21WB473,
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NTC_LAST,
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};
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static const struct platform_device_id ntc_thermistor_id[] = {
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[NTC_B57330V2103] = { "b57330v2103", TYPE_B57330V2103 },
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[NTC_B57891S0103] = { "b57891s0103", TYPE_B57891S0103 },
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[NTC_NCP03WB473] = { "ncp03wb473", TYPE_NCPXXWB473 },
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[NTC_NCP03WF104] = { "ncp03wf104", TYPE_NCPXXWF104 },
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[NTC_NCP15WB473] = { "ncp15wb473", TYPE_NCPXXWB473 },
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[NTC_NCP15WL333] = { "ncp15wl333", TYPE_NCPXXWL333 },
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[NTC_NCP15XH103] = { "ncp15xh103", TYPE_NCPXXXH103 },
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[NTC_NCP18WB473] = { "ncp18wb473", TYPE_NCPXXWB473 },
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[NTC_NCP21WB473] = { "ncp21wb473", TYPE_NCPXXWB473 },
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[NTC_LAST] = { },
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};
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/*
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* A compensation table should be sorted by the values of .ohm
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* in descending order.
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* The following compensation tables are from the specification of Murata NTC
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* Thermistors Datasheet
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*/
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static const struct ntc_compensation ncpXXwb473[] = {
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{ .temp_c = -40, .ohm = 1747920 },
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{ .temp_c = -35, .ohm = 1245428 },
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{ .temp_c = -30, .ohm = 898485 },
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{ .temp_c = -25, .ohm = 655802 },
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{ .temp_c = -20, .ohm = 483954 },
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{ .temp_c = -15, .ohm = 360850 },
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{ .temp_c = -10, .ohm = 271697 },
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{ .temp_c = -5, .ohm = 206463 },
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{ .temp_c = 0, .ohm = 158214 },
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{ .temp_c = 5, .ohm = 122259 },
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{ .temp_c = 10, .ohm = 95227 },
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{ .temp_c = 15, .ohm = 74730 },
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{ .temp_c = 20, .ohm = 59065 },
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{ .temp_c = 25, .ohm = 47000 },
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{ .temp_c = 30, .ohm = 37643 },
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{ .temp_c = 35, .ohm = 30334 },
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{ .temp_c = 40, .ohm = 24591 },
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{ .temp_c = 45, .ohm = 20048 },
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{ .temp_c = 50, .ohm = 16433 },
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{ .temp_c = 55, .ohm = 13539 },
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{ .temp_c = 60, .ohm = 11209 },
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{ .temp_c = 65, .ohm = 9328 },
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{ .temp_c = 70, .ohm = 7798 },
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{ .temp_c = 75, .ohm = 6544 },
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{ .temp_c = 80, .ohm = 5518 },
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{ .temp_c = 85, .ohm = 4674 },
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{ .temp_c = 90, .ohm = 3972 },
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{ .temp_c = 95, .ohm = 3388 },
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{ .temp_c = 100, .ohm = 2902 },
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{ .temp_c = 105, .ohm = 2494 },
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{ .temp_c = 110, .ohm = 2150 },
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{ .temp_c = 115, .ohm = 1860 },
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{ .temp_c = 120, .ohm = 1615 },
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{ .temp_c = 125, .ohm = 1406 },
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};
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static const struct ntc_compensation ncpXXwl333[] = {
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{ .temp_c = -40, .ohm = 1610154 },
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{ .temp_c = -35, .ohm = 1130850 },
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{ .temp_c = -30, .ohm = 802609 },
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{ .temp_c = -25, .ohm = 575385 },
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{ .temp_c = -20, .ohm = 416464 },
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{ .temp_c = -15, .ohm = 304219 },
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{ .temp_c = -10, .ohm = 224193 },
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{ .temp_c = -5, .ohm = 166623 },
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{ .temp_c = 0, .ohm = 124850 },
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{ .temp_c = 5, .ohm = 94287 },
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{ .temp_c = 10, .ohm = 71747 },
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{ .temp_c = 15, .ohm = 54996 },
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{ .temp_c = 20, .ohm = 42455 },
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{ .temp_c = 25, .ohm = 33000 },
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{ .temp_c = 30, .ohm = 25822 },
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{ .temp_c = 35, .ohm = 20335 },
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{ .temp_c = 40, .ohm = 16115 },
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{ .temp_c = 45, .ohm = 12849 },
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{ .temp_c = 50, .ohm = 10306 },
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{ .temp_c = 55, .ohm = 8314 },
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{ .temp_c = 60, .ohm = 6746 },
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{ .temp_c = 65, .ohm = 5503 },
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{ .temp_c = 70, .ohm = 4513 },
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{ .temp_c = 75, .ohm = 3721 },
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{ .temp_c = 80, .ohm = 3084 },
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{ .temp_c = 85, .ohm = 2569 },
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{ .temp_c = 90, .ohm = 2151 },
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{ .temp_c = 95, .ohm = 1809 },
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{ .temp_c = 100, .ohm = 1529 },
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{ .temp_c = 105, .ohm = 1299 },
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{ .temp_c = 110, .ohm = 1108 },
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{ .temp_c = 115, .ohm = 949 },
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{ .temp_c = 120, .ohm = 817 },
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{ .temp_c = 125, .ohm = 707 },
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};
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static const struct ntc_compensation ncpXXwf104[] = {
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{ .temp_c = -40, .ohm = 4397119 },
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{ .temp_c = -35, .ohm = 3088599 },
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{ .temp_c = -30, .ohm = 2197225 },
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{ .temp_c = -25, .ohm = 1581881 },
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{ .temp_c = -20, .ohm = 1151037 },
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{ .temp_c = -15, .ohm = 846579 },
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{ .temp_c = -10, .ohm = 628988 },
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{ .temp_c = -5, .ohm = 471632 },
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{ .temp_c = 0, .ohm = 357012 },
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{ .temp_c = 5, .ohm = 272500 },
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{ .temp_c = 10, .ohm = 209710 },
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{ .temp_c = 15, .ohm = 162651 },
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{ .temp_c = 20, .ohm = 127080 },
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{ .temp_c = 25, .ohm = 100000 },
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{ .temp_c = 30, .ohm = 79222 },
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{ .temp_c = 35, .ohm = 63167 },
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{ .temp_c = 40, .ohm = 50677 },
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{ .temp_c = 45, .ohm = 40904 },
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{ .temp_c = 50, .ohm = 33195 },
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{ .temp_c = 55, .ohm = 27091 },
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{ .temp_c = 60, .ohm = 22224 },
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{ .temp_c = 65, .ohm = 18323 },
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{ .temp_c = 70, .ohm = 15184 },
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{ .temp_c = 75, .ohm = 12635 },
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{ .temp_c = 80, .ohm = 10566 },
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{ .temp_c = 85, .ohm = 8873 },
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{ .temp_c = 90, .ohm = 7481 },
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{ .temp_c = 95, .ohm = 6337 },
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{ .temp_c = 100, .ohm = 5384 },
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{ .temp_c = 105, .ohm = 4594 },
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{ .temp_c = 110, .ohm = 3934 },
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{ .temp_c = 115, .ohm = 3380 },
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{ .temp_c = 120, .ohm = 2916 },
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{ .temp_c = 125, .ohm = 2522 },
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};
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static const struct ntc_compensation ncpXXxh103[] = {
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{ .temp_c = -40, .ohm = 247565 },
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{ .temp_c = -35, .ohm = 181742 },
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{ .temp_c = -30, .ohm = 135128 },
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{ .temp_c = -25, .ohm = 101678 },
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{ .temp_c = -20, .ohm = 77373 },
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{ .temp_c = -15, .ohm = 59504 },
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{ .temp_c = -10, .ohm = 46222 },
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{ .temp_c = -5, .ohm = 36244 },
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{ .temp_c = 0, .ohm = 28674 },
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{ .temp_c = 5, .ohm = 22878 },
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{ .temp_c = 10, .ohm = 18399 },
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{ .temp_c = 15, .ohm = 14910 },
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{ .temp_c = 20, .ohm = 12169 },
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{ .temp_c = 25, .ohm = 10000 },
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{ .temp_c = 30, .ohm = 8271 },
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{ .temp_c = 35, .ohm = 6883 },
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{ .temp_c = 40, .ohm = 5762 },
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{ .temp_c = 45, .ohm = 4851 },
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{ .temp_c = 50, .ohm = 4105 },
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{ .temp_c = 55, .ohm = 3492 },
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{ .temp_c = 60, .ohm = 2985 },
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{ .temp_c = 65, .ohm = 2563 },
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{ .temp_c = 70, .ohm = 2211 },
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{ .temp_c = 75, .ohm = 1915 },
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{ .temp_c = 80, .ohm = 1666 },
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{ .temp_c = 85, .ohm = 1454 },
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{ .temp_c = 90, .ohm = 1275 },
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{ .temp_c = 95, .ohm = 1121 },
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{ .temp_c = 100, .ohm = 990 },
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{ .temp_c = 105, .ohm = 876 },
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{ .temp_c = 110, .ohm = 779 },
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{ .temp_c = 115, .ohm = 694 },
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{ .temp_c = 120, .ohm = 620 },
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{ .temp_c = 125, .ohm = 556 },
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};
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/*
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* The following compensation tables are from the specifications in EPCOS NTC
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* Thermistors Datasheets
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*/
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static const struct ntc_compensation b57330v2103[] = {
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{ .temp_c = -40, .ohm = 190030 },
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{ .temp_c = -35, .ohm = 145360 },
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{ .temp_c = -30, .ohm = 112060 },
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{ .temp_c = -25, .ohm = 87041 },
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{ .temp_c = -20, .ohm = 68104 },
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{ .temp_c = -15, .ohm = 53665 },
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{ .temp_c = -10, .ohm = 42576 },
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{ .temp_c = -5, .ohm = 34001 },
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{ .temp_c = 0, .ohm = 27326 },
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{ .temp_c = 5, .ohm = 22096 },
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{ .temp_c = 10, .ohm = 17973 },
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{ .temp_c = 15, .ohm = 14703 },
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{ .temp_c = 20, .ohm = 12090 },
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{ .temp_c = 25, .ohm = 10000 },
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{ .temp_c = 30, .ohm = 8311 },
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{ .temp_c = 35, .ohm = 6941 },
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{ .temp_c = 40, .ohm = 5825 },
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{ .temp_c = 45, .ohm = 4911 },
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{ .temp_c = 50, .ohm = 4158 },
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{ .temp_c = 55, .ohm = 3536 },
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{ .temp_c = 60, .ohm = 3019 },
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{ .temp_c = 65, .ohm = 2588 },
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{ .temp_c = 70, .ohm = 2227 },
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{ .temp_c = 75, .ohm = 1924 },
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{ .temp_c = 80, .ohm = 1668 },
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{ .temp_c = 85, .ohm = 1451 },
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{ .temp_c = 90, .ohm = 1266 },
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{ .temp_c = 95, .ohm = 1108 },
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{ .temp_c = 100, .ohm = 973 },
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{ .temp_c = 105, .ohm = 857 },
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{ .temp_c = 110, .ohm = 757 },
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{ .temp_c = 115, .ohm = 671 },
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{ .temp_c = 120, .ohm = 596 },
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{ .temp_c = 125, .ohm = 531 },
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};
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static const struct ntc_compensation b57891s0103[] = {
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{ .temp_c = -55.0, .ohm = 878900 },
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{ .temp_c = -50.0, .ohm = 617590 },
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{ .temp_c = -45.0, .ohm = 439340 },
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{ .temp_c = -40.0, .ohm = 316180 },
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{ .temp_c = -35.0, .ohm = 230060 },
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{ .temp_c = -30.0, .ohm = 169150 },
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{ .temp_c = -25.0, .ohm = 125550 },
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{ .temp_c = -20.0, .ohm = 94143 },
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{ .temp_c = -15.0, .ohm = 71172 },
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{ .temp_c = -10.0, .ohm = 54308 },
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{ .temp_c = -5.0, .ohm = 41505 },
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{ .temp_c = 0.0, .ohm = 32014 },
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{ .temp_c = 5.0, .ohm = 25011 },
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{ .temp_c = 10.0, .ohm = 19691 },
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{ .temp_c = 15.0, .ohm = 15618 },
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{ .temp_c = 20.0, .ohm = 12474 },
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{ .temp_c = 25.0, .ohm = 10000 },
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{ .temp_c = 30.0, .ohm = 8080 },
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{ .temp_c = 35.0, .ohm = 6569 },
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{ .temp_c = 40.0, .ohm = 5372 },
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{ .temp_c = 45.0, .ohm = 4424 },
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{ .temp_c = 50.0, .ohm = 3661 },
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{ .temp_c = 55.0, .ohm = 3039 },
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{ .temp_c = 60.0, .ohm = 2536 },
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{ .temp_c = 65.0, .ohm = 2128 },
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{ .temp_c = 70.0, .ohm = 1794 },
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{ .temp_c = 75.0, .ohm = 1518 },
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{ .temp_c = 80.0, .ohm = 1290 },
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{ .temp_c = 85.0, .ohm = 1100 },
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{ .temp_c = 90.0, .ohm = 942 },
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{ .temp_c = 95.0, .ohm = 809 },
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{ .temp_c = 100.0, .ohm = 697 },
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{ .temp_c = 105.0, .ohm = 604 },
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{ .temp_c = 110.0, .ohm = 525 },
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{ .temp_c = 115.0, .ohm = 457 },
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{ .temp_c = 120.0, .ohm = 400 },
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{ .temp_c = 125.0, .ohm = 351 },
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{ .temp_c = 130.0, .ohm = 308 },
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{ .temp_c = 135.0, .ohm = 272 },
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{ .temp_c = 140.0, .ohm = 240 },
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{ .temp_c = 145.0, .ohm = 213 },
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{ .temp_c = 150.0, .ohm = 189 },
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{ .temp_c = 155.0, .ohm = 168 },
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};
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struct ntc_type {
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const struct ntc_compensation *comp;
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int n_comp;
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};
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#define NTC_TYPE(ntc, compensation) \
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[(ntc)] = { .comp = (compensation), .n_comp = ARRAY_SIZE(compensation) }
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static const struct ntc_type ntc_type[] = {
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NTC_TYPE(TYPE_B57330V2103, b57330v2103),
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NTC_TYPE(TYPE_B57891S0103, b57891s0103),
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NTC_TYPE(TYPE_NCPXXWB473, ncpXXwb473),
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NTC_TYPE(TYPE_NCPXXWF104, ncpXXwf104),
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NTC_TYPE(TYPE_NCPXXWL333, ncpXXwl333),
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NTC_TYPE(TYPE_NCPXXXH103, ncpXXxh103),
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};
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struct ntc_data {
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struct ntc_thermistor_platform_data *pdata;
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const struct ntc_compensation *comp;
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int n_comp;
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};
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#if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
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static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
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{
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struct iio_channel *channel = pdata->chan;
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int raw, uv, ret;
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ret = iio_read_channel_raw(channel, &raw);
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if (ret < 0) {
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pr_err("read channel() error: %d\n", ret);
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return ret;
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}
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ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000);
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if (ret < 0) {
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/* Assume 12 bit ADC with vref at pullup_uv */
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uv = (pdata->pullup_uv * (s64)raw) >> 12;
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}
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return uv;
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}
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static const struct of_device_id ntc_match[] = {
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{ .compatible = "epcos,b57330v2103",
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.data = &ntc_thermistor_id[NTC_B57330V2103]},
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{ .compatible = "epcos,b57891s0103",
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.data = &ntc_thermistor_id[NTC_B57891S0103] },
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{ .compatible = "murata,ncp03wb473",
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.data = &ntc_thermistor_id[NTC_NCP03WB473] },
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{ .compatible = "murata,ncp03wf104",
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.data = &ntc_thermistor_id[NTC_NCP03WF104] },
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{ .compatible = "murata,ncp15wb473",
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.data = &ntc_thermistor_id[NTC_NCP15WB473] },
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{ .compatible = "murata,ncp15wl333",
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.data = &ntc_thermistor_id[NTC_NCP15WL333] },
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{ .compatible = "murata,ncp15xh103",
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.data = &ntc_thermistor_id[NTC_NCP15XH103] },
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{ .compatible = "murata,ncp18wb473",
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.data = &ntc_thermistor_id[NTC_NCP18WB473] },
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{ .compatible = "murata,ncp21wb473",
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.data = &ntc_thermistor_id[NTC_NCP21WB473] },
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/* Usage of vendor name "ntc" is deprecated */
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{ .compatible = "ntc,ncp03wb473",
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.data = &ntc_thermistor_id[NTC_NCP03WB473] },
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{ .compatible = "ntc,ncp15wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP15WB473] },
|
|
{ .compatible = "ntc,ncp15wl333",
|
|
.data = &ntc_thermistor_id[NTC_NCP15WL333] },
|
|
{ .compatible = "ntc,ncp18wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP18WB473] },
|
|
{ .compatible = "ntc,ncp21wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP21WB473] },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ntc_match);
|
|
|
|
static struct ntc_thermistor_platform_data *
|
|
ntc_thermistor_parse_dt(struct device *dev)
|
|
{
|
|
struct iio_channel *chan;
|
|
enum iio_chan_type type;
|
|
struct device_node *np = dev->of_node;
|
|
struct ntc_thermistor_platform_data *pdata;
|
|
int ret;
|
|
|
|
if (!np)
|
|
return NULL;
|
|
|
|
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
|
|
if (!pdata)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
chan = devm_iio_channel_get(dev, NULL);
|
|
if (IS_ERR(chan))
|
|
return ERR_CAST(chan);
|
|
|
|
ret = iio_get_channel_type(chan, &type);
|
|
if (ret < 0)
|
|
return ERR_PTR(ret);
|
|
|
|
if (type != IIO_VOLTAGE)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uv))
|
|
return ERR_PTR(-ENODEV);
|
|
if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
|
|
return ERR_PTR(-ENODEV);
|
|
if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
if (of_find_property(np, "connected-positive", NULL))
|
|
pdata->connect = NTC_CONNECTED_POSITIVE;
|
|
else /* status change should be possible if not always on. */
|
|
pdata->connect = NTC_CONNECTED_GROUND;
|
|
|
|
pdata->chan = chan;
|
|
pdata->read_uv = ntc_adc_iio_read;
|
|
|
|
return pdata;
|
|
}
|
|
#else
|
|
static struct ntc_thermistor_platform_data *
|
|
ntc_thermistor_parse_dt(struct device *dev)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
#define ntc_match NULL
|
|
|
|
#endif
|
|
|
|
static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
|
|
{
|
|
if (divisor == 0 && dividend == 0)
|
|
return 0;
|
|
if (divisor == 0)
|
|
return UINT_MAX;
|
|
return div64_u64(dividend, divisor);
|
|
}
|
|
|
|
static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv)
|
|
{
|
|
struct ntc_thermistor_platform_data *pdata = data->pdata;
|
|
u32 puv = pdata->pullup_uv;
|
|
u64 n, puo, pdo;
|
|
puo = pdata->pullup_ohm;
|
|
pdo = pdata->pulldown_ohm;
|
|
|
|
if (uv == 0)
|
|
return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
|
|
INT_MAX : 0;
|
|
if (uv >= puv)
|
|
return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
|
|
0 : INT_MAX;
|
|
|
|
if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
|
|
n = div_u64(pdo * (puv - uv), uv);
|
|
else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
|
|
n = div_u64(puo * uv, puv - uv);
|
|
else if (pdata->connect == NTC_CONNECTED_POSITIVE)
|
|
n = div64_u64_safe(pdo * puo * (puv - uv),
|
|
puo * uv - pdo * (puv - uv));
|
|
else
|
|
n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv);
|
|
|
|
if (n > INT_MAX)
|
|
n = INT_MAX;
|
|
return n;
|
|
}
|
|
|
|
static void lookup_comp(struct ntc_data *data, unsigned int ohm,
|
|
int *i_low, int *i_high)
|
|
{
|
|
int start, end, mid;
|
|
|
|
/*
|
|
* Handle special cases: Resistance is higher than or equal to
|
|
* resistance in first table entry, or resistance is lower or equal
|
|
* to resistance in last table entry.
|
|
* In these cases, return i_low == i_high, either pointing to the
|
|
* beginning or to the end of the table depending on the condition.
|
|
*/
|
|
if (ohm >= data->comp[0].ohm) {
|
|
*i_low = 0;
|
|
*i_high = 0;
|
|
return;
|
|
}
|
|
if (ohm <= data->comp[data->n_comp - 1].ohm) {
|
|
*i_low = data->n_comp - 1;
|
|
*i_high = data->n_comp - 1;
|
|
return;
|
|
}
|
|
|
|
/* Do a binary search on compensation table */
|
|
start = 0;
|
|
end = data->n_comp;
|
|
while (start < end) {
|
|
mid = start + (end - start) / 2;
|
|
/*
|
|
* start <= mid < end
|
|
* data->comp[start].ohm > ohm >= data->comp[end].ohm
|
|
*
|
|
* We could check for "ohm == data->comp[mid].ohm" here, but
|
|
* that is a quite unlikely condition, and we would have to
|
|
* check again after updating start. Check it at the end instead
|
|
* for simplicity.
|
|
*/
|
|
if (ohm >= data->comp[mid].ohm) {
|
|
end = mid;
|
|
} else {
|
|
start = mid + 1;
|
|
/*
|
|
* ohm >= data->comp[start].ohm might be true here,
|
|
* since we set start to mid + 1. In that case, we are
|
|
* done. We could keep going, but the condition is quite
|
|
* likely to occur, so it is worth checking for it.
|
|
*/
|
|
if (ohm >= data->comp[start].ohm)
|
|
end = start;
|
|
}
|
|
/*
|
|
* start <= end
|
|
* data->comp[start].ohm >= ohm >= data->comp[end].ohm
|
|
*/
|
|
}
|
|
/*
|
|
* start == end
|
|
* ohm >= data->comp[end].ohm
|
|
*/
|
|
*i_low = end;
|
|
if (ohm == data->comp[end].ohm)
|
|
*i_high = end;
|
|
else
|
|
*i_high = end - 1;
|
|
}
|
|
|
|
static int get_temp_mc(struct ntc_data *data, unsigned int ohm)
|
|
{
|
|
int low, high;
|
|
int temp;
|
|
|
|
lookup_comp(data, ohm, &low, &high);
|
|
if (low == high) {
|
|
/* Unable to use linear approximation */
|
|
temp = data->comp[low].temp_c * 1000;
|
|
} else {
|
|
temp = data->comp[low].temp_c * 1000 +
|
|
((data->comp[high].temp_c - data->comp[low].temp_c) *
|
|
1000 * ((int)ohm - (int)data->comp[low].ohm)) /
|
|
((int)data->comp[high].ohm - (int)data->comp[low].ohm);
|
|
}
|
|
return temp;
|
|
}
|
|
|
|
static int ntc_thermistor_get_ohm(struct ntc_data *data)
|
|
{
|
|
int read_uv;
|
|
|
|
if (data->pdata->read_ohm)
|
|
return data->pdata->read_ohm();
|
|
|
|
if (data->pdata->read_uv) {
|
|
read_uv = data->pdata->read_uv(data->pdata);
|
|
if (read_uv < 0)
|
|
return read_uv;
|
|
return get_ohm_of_thermistor(data, read_uv);
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int ntc_read(struct device *dev, enum hwmon_sensor_types type,
|
|
u32 attr, int channel, long *val)
|
|
{
|
|
struct ntc_data *data = dev_get_drvdata(dev);
|
|
int ohm;
|
|
|
|
switch (type) {
|
|
case hwmon_temp:
|
|
switch (attr) {
|
|
case hwmon_temp_input:
|
|
ohm = ntc_thermistor_get_ohm(data);
|
|
if (ohm < 0)
|
|
return ohm;
|
|
*val = get_temp_mc(data, ohm);
|
|
return 0;
|
|
case hwmon_temp_type:
|
|
*val = 4;
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
static umode_t ntc_is_visible(const void *data, enum hwmon_sensor_types type,
|
|
u32 attr, int channel)
|
|
{
|
|
if (type == hwmon_temp) {
|
|
switch (attr) {
|
|
case hwmon_temp_input:
|
|
case hwmon_temp_type:
|
|
return 0444;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct hwmon_channel_info *ntc_info[] = {
|
|
HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
|
|
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_TYPE),
|
|
NULL
|
|
};
|
|
|
|
static const struct hwmon_ops ntc_hwmon_ops = {
|
|
.is_visible = ntc_is_visible,
|
|
.read = ntc_read,
|
|
};
|
|
|
|
static const struct hwmon_chip_info ntc_chip_info = {
|
|
.ops = &ntc_hwmon_ops,
|
|
.info = ntc_info,
|
|
};
|
|
|
|
static int ntc_thermistor_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
const struct of_device_id *of_id =
|
|
of_match_device(of_match_ptr(ntc_match), dev);
|
|
const struct platform_device_id *pdev_id;
|
|
struct ntc_thermistor_platform_data *pdata;
|
|
struct device *hwmon_dev;
|
|
struct ntc_data *data;
|
|
|
|
pdata = ntc_thermistor_parse_dt(dev);
|
|
if (IS_ERR(pdata))
|
|
return PTR_ERR(pdata);
|
|
else if (pdata == NULL)
|
|
pdata = dev_get_platdata(dev);
|
|
|
|
if (!pdata) {
|
|
dev_err(dev, "No platform init data supplied.\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* Either one of the two is required. */
|
|
if (!pdata->read_uv && !pdata->read_ohm) {
|
|
dev_err(dev,
|
|
"Both read_uv and read_ohm missing. Need either one of the two.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (pdata->read_uv && pdata->read_ohm) {
|
|
dev_warn(dev,
|
|
"Only one of read_uv and read_ohm is needed; ignoring read_uv.\n");
|
|
pdata->read_uv = NULL;
|
|
}
|
|
|
|
if (pdata->read_uv && (pdata->pullup_uv == 0 ||
|
|
(pdata->pullup_ohm == 0 && pdata->connect ==
|
|
NTC_CONNECTED_GROUND) ||
|
|
(pdata->pulldown_ohm == 0 && pdata->connect ==
|
|
NTC_CONNECTED_POSITIVE) ||
|
|
(pdata->connect != NTC_CONNECTED_POSITIVE &&
|
|
pdata->connect != NTC_CONNECTED_GROUND))) {
|
|
dev_err(dev, "Required data to use read_uv not supplied.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
data = devm_kzalloc(dev, sizeof(struct ntc_data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
|
|
|
|
data->pdata = pdata;
|
|
|
|
if (pdev_id->driver_data >= ARRAY_SIZE(ntc_type)) {
|
|
dev_err(dev, "Unknown device type: %lu(%s)\n",
|
|
pdev_id->driver_data, pdev_id->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
data->comp = ntc_type[pdev_id->driver_data].comp;
|
|
data->n_comp = ntc_type[pdev_id->driver_data].n_comp;
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_info(dev, pdev_id->name,
|
|
data, &ntc_chip_info,
|
|
NULL);
|
|
if (IS_ERR(hwmon_dev)) {
|
|
dev_err(dev, "unable to register as hwmon device.\n");
|
|
return PTR_ERR(hwmon_dev);
|
|
}
|
|
|
|
dev_info(dev, "Thermistor type: %s successfully probed.\n",
|
|
pdev_id->name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ntc_thermistor_driver = {
|
|
.driver = {
|
|
.name = "ntc-thermistor",
|
|
.of_match_table = of_match_ptr(ntc_match),
|
|
},
|
|
.probe = ntc_thermistor_probe,
|
|
.id_table = ntc_thermistor_id,
|
|
};
|
|
|
|
module_platform_driver(ntc_thermistor_driver);
|
|
|
|
MODULE_DESCRIPTION("NTC Thermistor Driver");
|
|
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:ntc-thermistor");
|