--- /dev/null
+/*
+ * 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},
+ { },
+};
+
+/*
+ * 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 },
+};
+
+/*
+ * 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 device *hwmon_dev;
+ struct ntc_thermistor_platform_data *pdata;
+ const struct ntc_compensation *comp;
+ struct device *dev;
+ int n_comp;
+ char name[PLATFORM_NAME_SIZE];
+ struct thermal_zone_device *tz;
+};
+
+#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;
+ s64 result;
+ int val, ret;
+
+ ret = iio_read_channel_raw(channel, &val);
+ if (ret < 0) {
+ pr_err("read channel() error: %d\n", ret);
+ return ret;
+ }
+
+ /* unit: mV */
+ result = pdata->pullup_uv * (s64) val;
+ result >>= 12;
+
+ return (int)result;
+}
+
+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]},
+
+ /* 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 platform_device *pdev)
+{
+ struct iio_channel *chan;
+ enum iio_chan_type type;
+ struct device_node *np = pdev->dev.of_node;
+ struct ntc_thermistor_platform_data *pdata;
+ int ret;
+
+ if (!np)
+ return NULL;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ chan = iio_channel_get(&pdev->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;
+}
+static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
+{
+ if (pdata->chan)
+ iio_channel_release(pdata->chan);
+}
+#else
+static struct ntc_thermistor_platform_data *
+ntc_thermistor_parse_dt(struct platform_device *pdev)
+{
+ return NULL;
+}
+
+#define ntc_match NULL
+
+static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
+{ }
+#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;
+ u64 mv = uv / 1000;
+ u64 pmv = pdata->pullup_uv / 1000;
+ u64 n, puo, pdo;
+ puo = pdata->pullup_ohm;
+ pdo = pdata->pulldown_ohm;
+
+ if (mv == 0) {
+ if (pdata->connect == NTC_CONNECTED_POSITIVE)
+ return INT_MAX;
+ return 0;
+ }
+ if (mv >= pmv)
+ return (pdata->connect == NTC_CONNECTED_POSITIVE) ?
+ 0 : INT_MAX;
+
+ if (pdata->connect == NTC_CONNECTED_POSITIVE && puo == 0)
+ n = div64_u64_safe(pdo * (pmv - mv), mv);
+ else if (pdata->connect == NTC_CONNECTED_GROUND && pdo == 0)
+ n = div64_u64_safe(puo * mv, pmv - mv);
+ else if (pdata->connect == NTC_CONNECTED_POSITIVE)
+ n = div64_u64_safe(pdo * puo * (pmv - mv),
+ puo * mv - pdo * (pmv - mv));
+ else
+ n = div64_u64_safe(pdo * puo * mv, pdo * (pmv - mv) - puo * mv);
+
+ 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 *dev, long *temp)
+{
+ struct ntc_data *data = dev_get_drvdata(dev);
+ 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_name(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ntc_data *data = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n", data->name);
+}
+
+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 DEVICE_ATTR(name, S_IRUGO, ntc_show_name, NULL);
+
+static struct attribute *ntc_attributes[] = {
+ &dev_attr_name.attr,
+ &sensor_dev_attr_temp1_type.dev_attr.attr,
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ntc_attr_group = {
+ .attrs = ntc_attributes,
+};
+
+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)
+{
+ const struct of_device_id *of_id =
+ of_match_device(of_match_ptr(ntc_match), &pdev->dev);
+ const struct platform_device_id *pdev_id;
+ struct ntc_thermistor_platform_data *pdata;
+ struct ntc_data *data;
+ int ret;
+
+ pdata = ntc_thermistor_parse_dt(pdev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ else if (pdata == NULL)
+ pdata = dev_get_platdata(&pdev->dev);
+
+ if (!pdata) {
+ dev_err(&pdev->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(&pdev->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(&pdev->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(&pdev->dev,
+ "Required data to use read_uv not supplied.\n");
+ return -EINVAL;
+ }
+
+ data = devm_kzalloc(&pdev->dev, sizeof(struct ntc_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
+
+ data->dev = &pdev->dev;
+ data->pdata = pdata;
+ strlcpy(data->name, pdev_id->name, sizeof(data->name));
+
+ 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;
+ default:
+ dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
+ pdev_id->driver_data, pdev_id->name);
+ return -EINVAL;
+ }
+
+ platform_set_drvdata(pdev, data);
+
+ ret = sysfs_create_group(&data->dev->kobj, &ntc_attr_group);
+ if (ret) {
+ dev_err(data->dev, "unable to create sysfs files\n");
+ return ret;
+ }
+
+ data->hwmon_dev = hwmon_device_register(data->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ dev_err(data->dev, "unable to register as hwmon device.\n");
+ ret = PTR_ERR(data->hwmon_dev);
+ goto err_after_sysfs;
+ }
+
+ dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
+ pdev_id->name);
+
+ data->tz = thermal_zone_of_sensor_register(data->dev, 0, data->dev,
+ &ntc_of_thermal_ops);
+ if (IS_ERR(data->tz)) {
+ dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n");
+ data->tz = NULL;
+ }
+
+ return 0;
+err_after_sysfs:
+ sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
+ ntc_iio_channel_release(pdata);
+ return ret;
+}
+
+static int ntc_thermistor_remove(struct platform_device *pdev)
+{
+ struct ntc_data *data = platform_get_drvdata(pdev);
+ struct ntc_thermistor_platform_data *pdata = data->pdata;
+
+ hwmon_device_unregister(data->hwmon_dev);
+ sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
+ ntc_iio_channel_release(pdata);
+
+ thermal_zone_of_sensor_unregister(data->dev, data->tz);
+
+ 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,
+ .remove = ntc_thermistor_remove,
+ .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");
Code Review / kvmfornfv.git / blobdiff