709 lines
20 KiB
C
709 lines
20 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* ntc_thermistor.c - NTC Thermistors
|
|
*
|
|
* Copyright (C) 2010 Samsung Electronics
|
|
* MyungJoo Ham <myungjoo.ham@samsung.com>
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/property.h>
|
|
#include <linux/err.h>
|
|
#include <linux/fixp-arith.h>
|
|
#include <linux/iio/consumer.h>
|
|
#include <linux/hwmon.h>
|
|
|
|
enum ntc_thermistor_type {
|
|
TYPE_B57330V2103,
|
|
TYPE_B57891S0103,
|
|
TYPE_NCPXXWB473,
|
|
TYPE_NCPXXWF104,
|
|
TYPE_NCPXXWL333,
|
|
TYPE_NCPXXXH103,
|
|
};
|
|
|
|
struct ntc_compensation {
|
|
int temp_c;
|
|
unsigned int ohm;
|
|
};
|
|
|
|
/*
|
|
* Used as index in a zero-terminated array, holes not allowed so
|
|
* that NTC_LAST is the first empty array entry.
|
|
*/
|
|
enum {
|
|
NTC_B57330V2103,
|
|
NTC_B57891S0103,
|
|
NTC_NCP03WB473,
|
|
NTC_NCP03WF104,
|
|
NTC_NCP15WB473,
|
|
NTC_NCP15WL333,
|
|
NTC_NCP15XH103,
|
|
NTC_NCP18WB473,
|
|
NTC_NCP21WB473,
|
|
NTC_SSG1404001221,
|
|
NTC_LAST,
|
|
};
|
|
|
|
static const struct platform_device_id ntc_thermistor_id[] = {
|
|
[NTC_B57330V2103] = { "b57330v2103", TYPE_B57330V2103 },
|
|
[NTC_B57891S0103] = { "b57891s0103", TYPE_B57891S0103 },
|
|
[NTC_NCP03WB473] = { "ncp03wb473", TYPE_NCPXXWB473 },
|
|
[NTC_NCP03WF104] = { "ncp03wf104", TYPE_NCPXXWF104 },
|
|
[NTC_NCP15WB473] = { "ncp15wb473", TYPE_NCPXXWB473 },
|
|
[NTC_NCP15WL333] = { "ncp15wl333", TYPE_NCPXXWL333 },
|
|
[NTC_NCP15XH103] = { "ncp15xh103", TYPE_NCPXXXH103 },
|
|
[NTC_NCP18WB473] = { "ncp18wb473", TYPE_NCPXXWB473 },
|
|
[NTC_NCP21WB473] = { "ncp21wb473", TYPE_NCPXXWB473 },
|
|
[NTC_SSG1404001221] = { "ssg1404_001221", TYPE_NCPXXWB473 },
|
|
[NTC_LAST] = { },
|
|
};
|
|
|
|
/*
|
|
* A compensation table should be sorted by the values of .ohm
|
|
* in descending order.
|
|
* The following compensation tables are from the specification of Murata NTC
|
|
* Thermistors Datasheet
|
|
*/
|
|
static const struct ntc_compensation ncpXXwb473[] = {
|
|
{ .temp_c = -40, .ohm = 1747920 },
|
|
{ .temp_c = -35, .ohm = 1245428 },
|
|
{ .temp_c = -30, .ohm = 898485 },
|
|
{ .temp_c = -25, .ohm = 655802 },
|
|
{ .temp_c = -20, .ohm = 483954 },
|
|
{ .temp_c = -15, .ohm = 360850 },
|
|
{ .temp_c = -10, .ohm = 271697 },
|
|
{ .temp_c = -5, .ohm = 206463 },
|
|
{ .temp_c = 0, .ohm = 158214 },
|
|
{ .temp_c = 5, .ohm = 122259 },
|
|
{ .temp_c = 10, .ohm = 95227 },
|
|
{ .temp_c = 15, .ohm = 74730 },
|
|
{ .temp_c = 20, .ohm = 59065 },
|
|
{ .temp_c = 25, .ohm = 47000 },
|
|
{ .temp_c = 30, .ohm = 37643 },
|
|
{ .temp_c = 35, .ohm = 30334 },
|
|
{ .temp_c = 40, .ohm = 24591 },
|
|
{ .temp_c = 45, .ohm = 20048 },
|
|
{ .temp_c = 50, .ohm = 16433 },
|
|
{ .temp_c = 55, .ohm = 13539 },
|
|
{ .temp_c = 60, .ohm = 11209 },
|
|
{ .temp_c = 65, .ohm = 9328 },
|
|
{ .temp_c = 70, .ohm = 7798 },
|
|
{ .temp_c = 75, .ohm = 6544 },
|
|
{ .temp_c = 80, .ohm = 5518 },
|
|
{ .temp_c = 85, .ohm = 4674 },
|
|
{ .temp_c = 90, .ohm = 3972 },
|
|
{ .temp_c = 95, .ohm = 3388 },
|
|
{ .temp_c = 100, .ohm = 2902 },
|
|
{ .temp_c = 105, .ohm = 2494 },
|
|
{ .temp_c = 110, .ohm = 2150 },
|
|
{ .temp_c = 115, .ohm = 1860 },
|
|
{ .temp_c = 120, .ohm = 1615 },
|
|
{ .temp_c = 125, .ohm = 1406 },
|
|
};
|
|
static const struct ntc_compensation ncpXXwl333[] = {
|
|
{ .temp_c = -40, .ohm = 1610154 },
|
|
{ .temp_c = -35, .ohm = 1130850 },
|
|
{ .temp_c = -30, .ohm = 802609 },
|
|
{ .temp_c = -25, .ohm = 575385 },
|
|
{ .temp_c = -20, .ohm = 416464 },
|
|
{ .temp_c = -15, .ohm = 304219 },
|
|
{ .temp_c = -10, .ohm = 224193 },
|
|
{ .temp_c = -5, .ohm = 166623 },
|
|
{ .temp_c = 0, .ohm = 124850 },
|
|
{ .temp_c = 5, .ohm = 94287 },
|
|
{ .temp_c = 10, .ohm = 71747 },
|
|
{ .temp_c = 15, .ohm = 54996 },
|
|
{ .temp_c = 20, .ohm = 42455 },
|
|
{ .temp_c = 25, .ohm = 33000 },
|
|
{ .temp_c = 30, .ohm = 25822 },
|
|
{ .temp_c = 35, .ohm = 20335 },
|
|
{ .temp_c = 40, .ohm = 16115 },
|
|
{ .temp_c = 45, .ohm = 12849 },
|
|
{ .temp_c = 50, .ohm = 10306 },
|
|
{ .temp_c = 55, .ohm = 8314 },
|
|
{ .temp_c = 60, .ohm = 6746 },
|
|
{ .temp_c = 65, .ohm = 5503 },
|
|
{ .temp_c = 70, .ohm = 4513 },
|
|
{ .temp_c = 75, .ohm = 3721 },
|
|
{ .temp_c = 80, .ohm = 3084 },
|
|
{ .temp_c = 85, .ohm = 2569 },
|
|
{ .temp_c = 90, .ohm = 2151 },
|
|
{ .temp_c = 95, .ohm = 1809 },
|
|
{ .temp_c = 100, .ohm = 1529 },
|
|
{ .temp_c = 105, .ohm = 1299 },
|
|
{ .temp_c = 110, .ohm = 1108 },
|
|
{ .temp_c = 115, .ohm = 949 },
|
|
{ .temp_c = 120, .ohm = 817 },
|
|
{ .temp_c = 125, .ohm = 707 },
|
|
};
|
|
|
|
static const struct ntc_compensation ncpXXwf104[] = {
|
|
{ .temp_c = -40, .ohm = 4397119 },
|
|
{ .temp_c = -35, .ohm = 3088599 },
|
|
{ .temp_c = -30, .ohm = 2197225 },
|
|
{ .temp_c = -25, .ohm = 1581881 },
|
|
{ .temp_c = -20, .ohm = 1151037 },
|
|
{ .temp_c = -15, .ohm = 846579 },
|
|
{ .temp_c = -10, .ohm = 628988 },
|
|
{ .temp_c = -5, .ohm = 471632 },
|
|
{ .temp_c = 0, .ohm = 357012 },
|
|
{ .temp_c = 5, .ohm = 272500 },
|
|
{ .temp_c = 10, .ohm = 209710 },
|
|
{ .temp_c = 15, .ohm = 162651 },
|
|
{ .temp_c = 20, .ohm = 127080 },
|
|
{ .temp_c = 25, .ohm = 100000 },
|
|
{ .temp_c = 30, .ohm = 79222 },
|
|
{ .temp_c = 35, .ohm = 63167 },
|
|
{ .temp_c = 40, .ohm = 50677 },
|
|
{ .temp_c = 45, .ohm = 40904 },
|
|
{ .temp_c = 50, .ohm = 33195 },
|
|
{ .temp_c = 55, .ohm = 27091 },
|
|
{ .temp_c = 60, .ohm = 22224 },
|
|
{ .temp_c = 65, .ohm = 18323 },
|
|
{ .temp_c = 70, .ohm = 15184 },
|
|
{ .temp_c = 75, .ohm = 12635 },
|
|
{ .temp_c = 80, .ohm = 10566 },
|
|
{ .temp_c = 85, .ohm = 8873 },
|
|
{ .temp_c = 90, .ohm = 7481 },
|
|
{ .temp_c = 95, .ohm = 6337 },
|
|
{ .temp_c = 100, .ohm = 5384 },
|
|
{ .temp_c = 105, .ohm = 4594 },
|
|
{ .temp_c = 110, .ohm = 3934 },
|
|
{ .temp_c = 115, .ohm = 3380 },
|
|
{ .temp_c = 120, .ohm = 2916 },
|
|
{ .temp_c = 125, .ohm = 2522 },
|
|
};
|
|
|
|
static const struct ntc_compensation ncpXXxh103[] = {
|
|
{ .temp_c = -40, .ohm = 247565 },
|
|
{ .temp_c = -35, .ohm = 181742 },
|
|
{ .temp_c = -30, .ohm = 135128 },
|
|
{ .temp_c = -25, .ohm = 101678 },
|
|
{ .temp_c = -20, .ohm = 77373 },
|
|
{ .temp_c = -15, .ohm = 59504 },
|
|
{ .temp_c = -10, .ohm = 46222 },
|
|
{ .temp_c = -5, .ohm = 36244 },
|
|
{ .temp_c = 0, .ohm = 28674 },
|
|
{ .temp_c = 5, .ohm = 22878 },
|
|
{ .temp_c = 10, .ohm = 18399 },
|
|
{ .temp_c = 15, .ohm = 14910 },
|
|
{ .temp_c = 20, .ohm = 12169 },
|
|
{ .temp_c = 25, .ohm = 10000 },
|
|
{ .temp_c = 30, .ohm = 8271 },
|
|
{ .temp_c = 35, .ohm = 6883 },
|
|
{ .temp_c = 40, .ohm = 5762 },
|
|
{ .temp_c = 45, .ohm = 4851 },
|
|
{ .temp_c = 50, .ohm = 4105 },
|
|
{ .temp_c = 55, .ohm = 3492 },
|
|
{ .temp_c = 60, .ohm = 2985 },
|
|
{ .temp_c = 65, .ohm = 2563 },
|
|
{ .temp_c = 70, .ohm = 2211 },
|
|
{ .temp_c = 75, .ohm = 1915 },
|
|
{ .temp_c = 80, .ohm = 1666 },
|
|
{ .temp_c = 85, .ohm = 1454 },
|
|
{ .temp_c = 90, .ohm = 1275 },
|
|
{ .temp_c = 95, .ohm = 1121 },
|
|
{ .temp_c = 100, .ohm = 990 },
|
|
{ .temp_c = 105, .ohm = 876 },
|
|
{ .temp_c = 110, .ohm = 779 },
|
|
{ .temp_c = 115, .ohm = 694 },
|
|
{ .temp_c = 120, .ohm = 620 },
|
|
{ .temp_c = 125, .ohm = 556 },
|
|
};
|
|
|
|
/*
|
|
* The following compensation tables are from the specifications in EPCOS NTC
|
|
* Thermistors Datasheets
|
|
*/
|
|
static const struct ntc_compensation b57330v2103[] = {
|
|
{ .temp_c = -40, .ohm = 190030 },
|
|
{ .temp_c = -35, .ohm = 145360 },
|
|
{ .temp_c = -30, .ohm = 112060 },
|
|
{ .temp_c = -25, .ohm = 87041 },
|
|
{ .temp_c = -20, .ohm = 68104 },
|
|
{ .temp_c = -15, .ohm = 53665 },
|
|
{ .temp_c = -10, .ohm = 42576 },
|
|
{ .temp_c = -5, .ohm = 34001 },
|
|
{ .temp_c = 0, .ohm = 27326 },
|
|
{ .temp_c = 5, .ohm = 22096 },
|
|
{ .temp_c = 10, .ohm = 17973 },
|
|
{ .temp_c = 15, .ohm = 14703 },
|
|
{ .temp_c = 20, .ohm = 12090 },
|
|
{ .temp_c = 25, .ohm = 10000 },
|
|
{ .temp_c = 30, .ohm = 8311 },
|
|
{ .temp_c = 35, .ohm = 6941 },
|
|
{ .temp_c = 40, .ohm = 5825 },
|
|
{ .temp_c = 45, .ohm = 4911 },
|
|
{ .temp_c = 50, .ohm = 4158 },
|
|
{ .temp_c = 55, .ohm = 3536 },
|
|
{ .temp_c = 60, .ohm = 3019 },
|
|
{ .temp_c = 65, .ohm = 2588 },
|
|
{ .temp_c = 70, .ohm = 2227 },
|
|
{ .temp_c = 75, .ohm = 1924 },
|
|
{ .temp_c = 80, .ohm = 1668 },
|
|
{ .temp_c = 85, .ohm = 1451 },
|
|
{ .temp_c = 90, .ohm = 1266 },
|
|
{ .temp_c = 95, .ohm = 1108 },
|
|
{ .temp_c = 100, .ohm = 973 },
|
|
{ .temp_c = 105, .ohm = 857 },
|
|
{ .temp_c = 110, .ohm = 757 },
|
|
{ .temp_c = 115, .ohm = 671 },
|
|
{ .temp_c = 120, .ohm = 596 },
|
|
{ .temp_c = 125, .ohm = 531 },
|
|
};
|
|
|
|
static const struct ntc_compensation b57891s0103[] = {
|
|
{ .temp_c = -55.0, .ohm = 878900 },
|
|
{ .temp_c = -50.0, .ohm = 617590 },
|
|
{ .temp_c = -45.0, .ohm = 439340 },
|
|
{ .temp_c = -40.0, .ohm = 316180 },
|
|
{ .temp_c = -35.0, .ohm = 230060 },
|
|
{ .temp_c = -30.0, .ohm = 169150 },
|
|
{ .temp_c = -25.0, .ohm = 125550 },
|
|
{ .temp_c = -20.0, .ohm = 94143 },
|
|
{ .temp_c = -15.0, .ohm = 71172 },
|
|
{ .temp_c = -10.0, .ohm = 54308 },
|
|
{ .temp_c = -5.0, .ohm = 41505 },
|
|
{ .temp_c = 0.0, .ohm = 32014 },
|
|
{ .temp_c = 5.0, .ohm = 25011 },
|
|
{ .temp_c = 10.0, .ohm = 19691 },
|
|
{ .temp_c = 15.0, .ohm = 15618 },
|
|
{ .temp_c = 20.0, .ohm = 12474 },
|
|
{ .temp_c = 25.0, .ohm = 10000 },
|
|
{ .temp_c = 30.0, .ohm = 8080 },
|
|
{ .temp_c = 35.0, .ohm = 6569 },
|
|
{ .temp_c = 40.0, .ohm = 5372 },
|
|
{ .temp_c = 45.0, .ohm = 4424 },
|
|
{ .temp_c = 50.0, .ohm = 3661 },
|
|
{ .temp_c = 55.0, .ohm = 3039 },
|
|
{ .temp_c = 60.0, .ohm = 2536 },
|
|
{ .temp_c = 65.0, .ohm = 2128 },
|
|
{ .temp_c = 70.0, .ohm = 1794 },
|
|
{ .temp_c = 75.0, .ohm = 1518 },
|
|
{ .temp_c = 80.0, .ohm = 1290 },
|
|
{ .temp_c = 85.0, .ohm = 1100 },
|
|
{ .temp_c = 90.0, .ohm = 942 },
|
|
{ .temp_c = 95.0, .ohm = 809 },
|
|
{ .temp_c = 100.0, .ohm = 697 },
|
|
{ .temp_c = 105.0, .ohm = 604 },
|
|
{ .temp_c = 110.0, .ohm = 525 },
|
|
{ .temp_c = 115.0, .ohm = 457 },
|
|
{ .temp_c = 120.0, .ohm = 400 },
|
|
{ .temp_c = 125.0, .ohm = 351 },
|
|
{ .temp_c = 130.0, .ohm = 308 },
|
|
{ .temp_c = 135.0, .ohm = 272 },
|
|
{ .temp_c = 140.0, .ohm = 240 },
|
|
{ .temp_c = 145.0, .ohm = 213 },
|
|
{ .temp_c = 150.0, .ohm = 189 },
|
|
{ .temp_c = 155.0, .ohm = 168 },
|
|
};
|
|
|
|
struct ntc_type {
|
|
const struct ntc_compensation *comp;
|
|
int n_comp;
|
|
};
|
|
|
|
#define NTC_TYPE(ntc, compensation) \
|
|
[(ntc)] = { .comp = (compensation), .n_comp = ARRAY_SIZE(compensation) }
|
|
|
|
static const struct ntc_type ntc_type[] = {
|
|
NTC_TYPE(TYPE_B57330V2103, b57330v2103),
|
|
NTC_TYPE(TYPE_B57891S0103, b57891s0103),
|
|
NTC_TYPE(TYPE_NCPXXWB473, ncpXXwb473),
|
|
NTC_TYPE(TYPE_NCPXXWF104, ncpXXwf104),
|
|
NTC_TYPE(TYPE_NCPXXWL333, ncpXXwl333),
|
|
NTC_TYPE(TYPE_NCPXXXH103, ncpXXxh103),
|
|
};
|
|
|
|
/*
|
|
* pullup_uV, pullup_ohm, pulldown_ohm, and connect are required.
|
|
*
|
|
* How to setup pullup_ohm, pulldown_ohm, and connect is
|
|
* described at Documentation/hwmon/ntc_thermistor.rst
|
|
*
|
|
* pullup/down_ohm: 0 for infinite / not-connected
|
|
*
|
|
* chan: iio_channel pointer to communicate with the ADC which the
|
|
* thermistor is using for conversion of the analog values.
|
|
*/
|
|
struct ntc_data {
|
|
const struct ntc_compensation *comp;
|
|
int n_comp;
|
|
unsigned int pullup_uv;
|
|
unsigned int pullup_ohm;
|
|
unsigned int pulldown_ohm;
|
|
enum { NTC_CONNECTED_POSITIVE, NTC_CONNECTED_GROUND } connect;
|
|
struct iio_channel *chan;
|
|
};
|
|
|
|
static int ntc_adc_iio_read(struct ntc_data *data)
|
|
{
|
|
struct iio_channel *channel = data->chan;
|
|
int uv, ret;
|
|
|
|
ret = iio_read_channel_processed_scale(channel, &uv, 1000);
|
|
if (ret < 0) {
|
|
int raw;
|
|
|
|
/*
|
|
* This fallback uses a raw read and then
|
|
* assumes the ADC is 12 bits, scaling with
|
|
* a factor 1000 to get to microvolts.
|
|
*/
|
|
ret = iio_read_channel_raw(channel, &raw);
|
|
if (ret < 0) {
|
|
pr_err("read channel() error: %d\n", ret);
|
|
return ret;
|
|
}
|
|
ret = iio_convert_raw_to_processed(channel, raw, &uv, 1000);
|
|
if (ret < 0) {
|
|
/* Assume 12 bit ADC with vref at pullup_uv */
|
|
uv = (data->pullup_uv * (s64)raw) >> 12;
|
|
}
|
|
}
|
|
|
|
return uv;
|
|
}
|
|
|
|
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)
|
|
{
|
|
u32 puv = data->pullup_uv;
|
|
u64 n, puo, pdo;
|
|
puo = data->pullup_ohm;
|
|
pdo = data->pulldown_ohm;
|
|
|
|
if (uv == 0)
|
|
return (data->connect == NTC_CONNECTED_POSITIVE) ?
|
|
INT_MAX : 0;
|
|
if (uv >= puv)
|
|
return (data->connect == NTC_CONNECTED_POSITIVE) ?
|
|
0 : INT_MAX;
|
|
|
|
if (data->connect == NTC_CONNECTED_POSITIVE && puo == 0)
|
|
n = div_u64(pdo * (puv - uv), uv);
|
|
else if (data->connect == NTC_CONNECTED_GROUND && pdo == 0)
|
|
n = div_u64(puo * uv, puv - uv);
|
|
else if (data->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);
|
|
/*
|
|
* First multiplying the table temperatures with 1000 to get to
|
|
* millicentigrades (which is what we want) and then interpolating
|
|
* will give the best precision.
|
|
*/
|
|
temp = fixp_linear_interpolate(data->comp[low].ohm,
|
|
data->comp[low].temp_c * 1000,
|
|
data->comp[high].ohm,
|
|
data->comp[high].temp_c * 1000,
|
|
ohm);
|
|
return temp;
|
|
}
|
|
|
|
static int ntc_thermistor_get_ohm(struct ntc_data *data)
|
|
{
|
|
int read_uv;
|
|
|
|
read_uv = ntc_adc_iio_read(data);
|
|
if (read_uv < 0)
|
|
return read_uv;
|
|
return get_ohm_of_thermistor(data, read_uv);
|
|
}
|
|
|
|
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 * const 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_parse_props(struct device *dev,
|
|
struct ntc_data *data)
|
|
{
|
|
struct iio_channel *chan;
|
|
enum iio_chan_type type;
|
|
int ret;
|
|
|
|
chan = devm_iio_channel_get(dev, NULL);
|
|
if (IS_ERR(chan))
|
|
return PTR_ERR(chan);
|
|
|
|
ret = iio_get_channel_type(chan, &type);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (type != IIO_VOLTAGE)
|
|
return -EINVAL;
|
|
|
|
ret = device_property_read_u32(dev, "pullup-uv", &data->pullup_uv);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "pullup-uv not specified\n");
|
|
|
|
ret = device_property_read_u32(dev, "pullup-ohm", &data->pullup_ohm);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "pullup-ohm not specified\n");
|
|
|
|
ret = device_property_read_u32(dev, "pulldown-ohm", &data->pulldown_ohm);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "pulldown-ohm not specified\n");
|
|
|
|
if (device_property_read_bool(dev, "connected-positive"))
|
|
data->connect = NTC_CONNECTED_POSITIVE;
|
|
else /* status change should be possible if not always on. */
|
|
data->connect = NTC_CONNECTED_GROUND;
|
|
|
|
data->chan = chan;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ntc_thermistor_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
const struct platform_device_id *pdev_id;
|
|
struct device *hwmon_dev;
|
|
struct ntc_data *data;
|
|
int ret;
|
|
|
|
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
ret = ntc_thermistor_parse_props(dev, data);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (data->pullup_uv == 0 ||
|
|
(data->pullup_ohm == 0 && data->connect ==
|
|
NTC_CONNECTED_GROUND) ||
|
|
(data->pulldown_ohm == 0 && data->connect ==
|
|
NTC_CONNECTED_POSITIVE) ||
|
|
(data->connect != NTC_CONNECTED_POSITIVE &&
|
|
data->connect != NTC_CONNECTED_GROUND)) {
|
|
dev_err(dev, "Required data to use NTC driver not supplied.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
pdev_id = device_get_match_data(dev);
|
|
|
|
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 const struct of_device_id ntc_match[] = {
|
|
{ .compatible = "epcos,b57330v2103",
|
|
.data = &ntc_thermistor_id[NTC_B57330V2103]},
|
|
{ .compatible = "epcos,b57891s0103",
|
|
.data = &ntc_thermistor_id[NTC_B57891S0103] },
|
|
{ .compatible = "murata,ncp03wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP03WB473] },
|
|
{ .compatible = "murata,ncp03wf104",
|
|
.data = &ntc_thermistor_id[NTC_NCP03WF104] },
|
|
{ .compatible = "murata,ncp15wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP15WB473] },
|
|
{ .compatible = "murata,ncp15wl333",
|
|
.data = &ntc_thermistor_id[NTC_NCP15WL333] },
|
|
{ .compatible = "murata,ncp15xh103",
|
|
.data = &ntc_thermistor_id[NTC_NCP15XH103] },
|
|
{ .compatible = "murata,ncp18wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP18WB473] },
|
|
{ .compatible = "murata,ncp21wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP21WB473] },
|
|
{ .compatible = "samsung,1404-001221",
|
|
.data = &ntc_thermistor_id[NTC_SSG1404001221] },
|
|
|
|
/* Usage of vendor name "ntc" is deprecated */
|
|
{ .compatible = "ntc,ncp03wb473",
|
|
.data = &ntc_thermistor_id[NTC_NCP03WB473] },
|
|
{ .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 platform_driver ntc_thermistor_driver = {
|
|
.driver = {
|
|
.name = "ntc-thermistor",
|
|
.of_match_table = 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");
|