--- /dev/null
+/*
+ * tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor
+ *
+ * Copyright (c) 2015 Measurement-Specialties
+ *
+ * Licensed under the GPL-2.
+ *
+ * Datasheet:
+ * http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/stat.h>
+#include "../common/ms_sensors/ms_sensors_i2c.h"
+
+/* TSYS01 Commands */
+#define TSYS01_RESET 0x1E
+#define TSYS01_CONVERSION_START 0x48
+#define TSYS01_ADC_READ 0x00
+#define TSYS01_PROM_READ 0xA0
+
+#define TSYS01_PROM_WORDS_NB 8
+
+struct tsys01_dev {
+ void *client;
+ struct mutex lock; /* lock during conversion */
+
+ int (*reset)(void *cli, u8 cmd, unsigned int delay);
+ int (*convert_and_read)(void *cli, u8 conv, u8 rd,
+ unsigned int delay, u32 *adc);
+ int (*read_prom_word)(void *cli, int cmd, u16 *word);
+
+ u16 prom[TSYS01_PROM_WORDS_NB];
+};
+
+/* Multiplication coefficients for temperature computation */
+static const int coeff_mul[] = { -1500000, 1000000, -2000000,
+ 4000000, -2000000 };
+
+static int tsys01_read_temperature(struct iio_dev *indio_dev,
+ s32 *temperature)
+{
+ int ret, i;
+ u32 adc;
+ s64 temp = 0;
+ struct tsys01_dev *dev_data = iio_priv(indio_dev);
+
+ mutex_lock(&dev_data->lock);
+ ret = dev_data->convert_and_read(dev_data->client,
+ TSYS01_CONVERSION_START,
+ TSYS01_ADC_READ, 9000, &adc);
+ mutex_unlock(&dev_data->lock);
+ if (ret)
+ return ret;
+
+ adc >>= 8;
+
+ /* Temperature algorithm */
+ for (i = 4; i > 0; i--) {
+ temp += coeff_mul[i] *
+ (s64)dev_data->prom[5 - i];
+ temp *= (s64)adc;
+ temp = div64_s64(temp, 100000);
+ }
+ temp *= 10;
+ temp += coeff_mul[0] * (s64)dev_data->prom[5];
+ temp = div64_s64(temp, 100000);
+
+ *temperature = temp;
+
+ return 0;
+}
+
+static int tsys01_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ int ret;
+ s32 temperature;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ switch (channel->type) {
+ case IIO_TEMP: /* in milli °C */
+ ret = tsys01_read_temperature(indio_dev, &temperature);
+ if (ret)
+ return ret;
+ *val = temperature;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_chan_spec tsys01_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
+ }
+};
+
+static const struct iio_info tsys01_info = {
+ .read_raw = tsys01_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static bool tsys01_crc_valid(u16 *n_prom)
+{
+ u8 cnt;
+ u8 sum = 0;
+
+ for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++)
+ sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF));
+
+ return (sum == 0);
+}
+
+static int tsys01_read_prom(struct iio_dev *indio_dev)
+{
+ int i, ret;
+ struct tsys01_dev *dev_data = iio_priv(indio_dev);
+ char buf[7 * TSYS01_PROM_WORDS_NB + 1];
+ char *ptr = buf;
+
+ for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) {
+ ret = dev_data->read_prom_word(dev_data->client,
+ TSYS01_PROM_READ + (i << 1),
+ &dev_data->prom[i]);
+ if (ret)
+ return ret;
+
+ ret = sprintf(ptr, "0x%04x ", dev_data->prom[i]);
+ ptr += ret;
+ }
+
+ if (!tsys01_crc_valid(dev_data->prom)) {
+ dev_err(&indio_dev->dev, "prom crc check error\n");
+ return -ENODEV;
+ }
+ *ptr = 0;
+ dev_info(&indio_dev->dev, "PROM coefficients : %s\n", buf);
+
+ return 0;
+}
+
+static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev)
+{
+ int ret;
+ struct tsys01_dev *dev_data = iio_priv(indio_dev);
+
+ mutex_init(&dev_data->lock);
+
+ indio_dev->info = &tsys01_info;
+ indio_dev->name = dev->driver->name;
+ indio_dev->dev.parent = dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = tsys01_channels;
+ indio_dev->num_channels = ARRAY_SIZE(tsys01_channels);
+
+ ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000);
+ if (ret)
+ return ret;
+
+ ret = tsys01_read_prom(indio_dev);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static int tsys01_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct tsys01_dev *dev_data;
+ struct iio_dev *indio_dev;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_WRITE_BYTE |
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+ dev_err(&client->dev,
+ "Adapter does not support some i2c transaction\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ dev_data = iio_priv(indio_dev);
+ dev_data->client = client;
+ dev_data->reset = ms_sensors_reset;
+ dev_data->read_prom_word = ms_sensors_read_prom_word;
+ dev_data->convert_and_read = ms_sensors_convert_and_read;
+
+ i2c_set_clientdata(client, indio_dev);
+
+ return tsys01_probe(indio_dev, &client->dev);
+}
+
+static const struct i2c_device_id tsys01_id[] = {
+ {"tsys01", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, tsys01_id);
+
+static struct i2c_driver tsys01_driver = {
+ .probe = tsys01_i2c_probe,
+ .id_table = tsys01_id,
+ .driver = {
+ .name = "tsys01",
+ },
+};
+
+module_i2c_driver(tsys01_driver);
+
+MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature driver");
+MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
+MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
+MODULE_LICENSE("GPL v2");
projects / karo-tx-linux.git / commitdiff