diff options
Diffstat (limited to 'drivers/hwmon/ntc_thermistor.c')
| -rw-r--r-- | drivers/hwmon/ntc_thermistor.c | 724 |
1 files changed, 724 insertions, 0 deletions
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c new file mode 100644 index 000000000..3aad62a0e --- /dev/null +++ b/drivers/hwmon/ntc_thermistor.c @@ -0,0 +1,724 @@ +// 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/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> + +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_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_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), +}; + +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 = "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] }, + + /* 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 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"); |