|  | /* | 
|  | * ntc_thermistor.c - NTC Thermistors | 
|  | * | 
|  | *  Copyright (C) 2010 Samsung Electronics | 
|  | *  MyungJoo Ham <myungjoo.ham@samsung.com> | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify | 
|  | * it under the terms of the GNU General Public License as published by | 
|  | * the Free Software Foundation; either version 2 of the License, or | 
|  | * (at your option) any later version. | 
|  | * | 
|  | * This program is distributed in the hope that it will be useful, | 
|  | * but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
|  | * GNU General Public License for more details. | 
|  | * | 
|  | * You should have received a copy of the GNU General Public License | 
|  | * along with this program; if not, write to the Free Software | 
|  | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA | 
|  | * | 
|  | */ | 
|  |  | 
|  | #include <linux/slab.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/pm_runtime.h> | 
|  | #include <linux/math64.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/of.h> | 
|  | #include <linux/of_device.h> | 
|  |  | 
|  | #include <linux/platform_data/ntc_thermistor.h> | 
|  |  | 
|  | #include <linux/iio/iio.h> | 
|  | #include <linux/iio/machine.h> | 
|  | #include <linux/iio/driver.h> | 
|  | #include <linux/iio/consumer.h> | 
|  |  | 
|  | #include <linux/hwmon.h> | 
|  | #include <linux/hwmon-sysfs.h> | 
|  | #include <linux/thermal.h> | 
|  |  | 
|  | struct ntc_compensation { | 
|  | int		temp_c; | 
|  | unsigned int	ohm; | 
|  | }; | 
|  |  | 
|  | /* Order matters, ntc_match references the entries by index */ | 
|  | static const struct platform_device_id ntc_thermistor_id[] = { | 
|  | { "ncp15wb473", TYPE_NCPXXWB473 }, | 
|  | { "ncp18wb473", TYPE_NCPXXWB473 }, | 
|  | { "ncp21wb473", TYPE_NCPXXWB473 }, | 
|  | { "ncp03wb473", TYPE_NCPXXWB473 }, | 
|  | { "ncp15wl333", TYPE_NCPXXWL333 }, | 
|  | { "b57330v2103", TYPE_B57330V2103}, | 
|  | { "ncp03wf104", TYPE_NCPXXWF104 }, | 
|  | { "ncp15xh103", TYPE_NCPXXXH103 }, | 
|  | { }, | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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 table is from the specification of EPCOS NTC | 
|  | * Thermistors Datasheet | 
|  | */ | 
|  | 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 }, | 
|  | }; | 
|  |  | 
|  | struct ntc_data { | 
|  | struct ntc_thermistor_platform_data *pdata; | 
|  | const struct ntc_compensation *comp; | 
|  | int n_comp; | 
|  | }; | 
|  |  | 
|  | #if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO) | 
|  | static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata) | 
|  | { | 
|  | struct iio_channel *channel = pdata->chan; | 
|  | int raw, uv, ret; | 
|  |  | 
|  | 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 = (pdata->pullup_uv * (s64)raw) >> 12; | 
|  | } | 
|  |  | 
|  | return uv; | 
|  | } | 
|  |  | 
|  | static const struct of_device_id ntc_match[] = { | 
|  | { .compatible = "murata,ncp15wb473", | 
|  | .data = &ntc_thermistor_id[0] }, | 
|  | { .compatible = "murata,ncp18wb473", | 
|  | .data = &ntc_thermistor_id[1] }, | 
|  | { .compatible = "murata,ncp21wb473", | 
|  | .data = &ntc_thermistor_id[2] }, | 
|  | { .compatible = "murata,ncp03wb473", | 
|  | .data = &ntc_thermistor_id[3] }, | 
|  | { .compatible = "murata,ncp15wl333", | 
|  | .data = &ntc_thermistor_id[4] }, | 
|  | { .compatible = "epcos,b57330v2103", | 
|  | .data = &ntc_thermistor_id[5]}, | 
|  | { .compatible = "murata,ncp03wf104", | 
|  | .data = &ntc_thermistor_id[6] }, | 
|  | { .compatible = "murata,ncp15xh103", | 
|  | .data = &ntc_thermistor_id[7] }, | 
|  |  | 
|  | /* Usage of vendor name "ntc" is deprecated */ | 
|  | { .compatible = "ntc,ncp15wb473", | 
|  | .data = &ntc_thermistor_id[0] }, | 
|  | { .compatible = "ntc,ncp18wb473", | 
|  | .data = &ntc_thermistor_id[1] }, | 
|  | { .compatible = "ntc,ncp21wb473", | 
|  | .data = &ntc_thermistor_id[2] }, | 
|  | { .compatible = "ntc,ncp03wb473", | 
|  | .data = &ntc_thermistor_id[3] }, | 
|  | { .compatible = "ntc,ncp15wl333", | 
|  | .data = &ntc_thermistor_id[4] }, | 
|  | { }, | 
|  | }; | 
|  | 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_temp(void *data, int *temp) | 
|  | { | 
|  | int ohm; | 
|  |  | 
|  | ohm = ntc_thermistor_get_ohm(data); | 
|  | if (ohm < 0) | 
|  | return ohm; | 
|  |  | 
|  | *temp = get_temp_mc(data, ohm); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static ssize_t ntc_show_type(struct device *dev, | 
|  | struct device_attribute *attr, char *buf) | 
|  | { | 
|  | return sprintf(buf, "4\n"); | 
|  | } | 
|  |  | 
|  | static ssize_t ntc_show_temp(struct device *dev, | 
|  | struct device_attribute *attr, char *buf) | 
|  | { | 
|  | struct ntc_data *data = dev_get_drvdata(dev); | 
|  | int ohm; | 
|  |  | 
|  | ohm = ntc_thermistor_get_ohm(data); | 
|  | if (ohm < 0) | 
|  | return ohm; | 
|  |  | 
|  | return sprintf(buf, "%d\n", get_temp_mc(data, ohm)); | 
|  | } | 
|  |  | 
|  | static SENSOR_DEVICE_ATTR(temp1_type, S_IRUGO, ntc_show_type, NULL, 0); | 
|  | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ntc_show_temp, NULL, 0); | 
|  |  | 
|  | static struct attribute *ntc_attrs[] = { | 
|  | &sensor_dev_attr_temp1_type.dev_attr.attr, | 
|  | &sensor_dev_attr_temp1_input.dev_attr.attr, | 
|  | NULL, | 
|  | }; | 
|  | ATTRIBUTE_GROUPS(ntc); | 
|  |  | 
|  | static const struct thermal_zone_of_device_ops ntc_of_thermal_ops = { | 
|  | .get_temp = ntc_read_temp, | 
|  | }; | 
|  |  | 
|  | static int ntc_thermistor_probe(struct platform_device *pdev) | 
|  | { | 
|  | struct thermal_zone_device *tz; | 
|  | 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; | 
|  |  | 
|  | switch (pdev_id->driver_data) { | 
|  | case TYPE_NCPXXWB473: | 
|  | data->comp = ncpXXwb473; | 
|  | data->n_comp = ARRAY_SIZE(ncpXXwb473); | 
|  | break; | 
|  | case TYPE_NCPXXWL333: | 
|  | data->comp = ncpXXwl333; | 
|  | data->n_comp = ARRAY_SIZE(ncpXXwl333); | 
|  | break; | 
|  | case TYPE_B57330V2103: | 
|  | data->comp = b57330v2103; | 
|  | data->n_comp = ARRAY_SIZE(b57330v2103); | 
|  | break; | 
|  | case TYPE_NCPXXWF104: | 
|  | data->comp = ncpXXwf104; | 
|  | data->n_comp = ARRAY_SIZE(ncpXXwf104); | 
|  | break; | 
|  | case TYPE_NCPXXXH103: | 
|  | data->comp = ncpXXxh103; | 
|  | data->n_comp = ARRAY_SIZE(ncpXXxh103); | 
|  | break; | 
|  | default: | 
|  | dev_err(dev, "Unknown device type: %lu(%s)\n", | 
|  | pdev_id->driver_data, pdev_id->name); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | hwmon_dev = devm_hwmon_device_register_with_groups(dev, pdev_id->name, | 
|  | data, ntc_groups); | 
|  | 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); | 
|  |  | 
|  | tz = devm_thermal_zone_of_sensor_register(dev, 0, data, | 
|  | &ntc_of_thermal_ops); | 
|  | if (IS_ERR(tz)) | 
|  | dev_dbg(dev, "Failed to register to thermal fw.\n"); | 
|  |  | 
|  | 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"); |