--- /dev/null
+/*
+ * hp206c.c - HOPERF HP206C precision barometer and altimeter sensor
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * (7-bit I2C slave address 0x76)
+ *
+ * Datasheet:
+ * http://www.hoperf.com/upload/sensor/HP206C_DataSheet_EN_V2.0.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/delay.h>
+#include <linux/util_macros.h>
+#include <linux/acpi.h>
+
+/* I2C commands: */
+#define HP206C_CMD_SOFT_RST 0x06
+
+#define HP206C_CMD_ADC_CVT 0x40
+
+#define HP206C_CMD_ADC_CVT_OSR_4096 0x00
+#define HP206C_CMD_ADC_CVT_OSR_2048 0x04
+#define HP206C_CMD_ADC_CVT_OSR_1024 0x08
+#define HP206C_CMD_ADC_CVT_OSR_512 0x0c
+#define HP206C_CMD_ADC_CVT_OSR_256 0x10
+#define HP206C_CMD_ADC_CVT_OSR_128 0x14
+
+#define HP206C_CMD_ADC_CVT_CHNL_PT 0x00
+#define HP206C_CMD_ADC_CVT_CHNL_T 0x02
+
+#define HP206C_CMD_READ_P 0x30
+#define HP206C_CMD_READ_T 0x32
+
+#define HP206C_CMD_READ_REG 0x80
+#define HP206C_CMD_WRITE_REG 0xc0
+
+#define HP206C_REG_INT_EN 0x0b
+#define HP206C_REG_INT_CFG 0x0c
+
+#define HP206C_REG_INT_SRC 0x0d
+#define HP206C_FLAG_DEV_RDY 0x40
+
+#define HP206C_REG_PARA 0x0f
+#define HP206C_FLAG_CMPS_EN 0x80
+
+/* Maximum spin for DEV_RDY */
+#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20
+#define HP206C_DEV_RDY_WAIT_US 20000
+
+struct hp206c_data {
+ struct mutex mutex;
+ struct i2c_client *client;
+ int temp_osr_index;
+ int pres_osr_index;
+};
+
+struct hp206c_osr_setting {
+ u8 osr_mask;
+ unsigned int temp_conv_time_us;
+ unsigned int pres_conv_time_us;
+};
+
+/* Data from Table 5 in datasheet. */
+static const struct hp206c_osr_setting hp206c_osr_settings[] = {
+ { HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 },
+ { HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 },
+ { HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 },
+ { HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 },
+ { HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 },
+ { HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 },
+};
+static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };
+static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";
+
+static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)
+{
+ return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);
+}
+
+static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)
+{
+ return i2c_smbus_write_byte_data(client,
+ HP206C_CMD_WRITE_REG | reg, val);
+}
+
+static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)
+{
+ int ret;
+ u8 values[3];
+
+ ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values);
+ if (ret < 0)
+ return ret;
+ if (ret != 3)
+ return -EIO;
+ return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]);
+}
+
+/* Spin for max 160ms until DEV_RDY is 1, or return error. */
+static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)
+{
+ int ret;
+ int count = 0;
+ struct hp206c_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+
+ while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {
+ ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);
+ return ret;
+ }
+ if (ret & HP206C_FLAG_DEV_RDY)
+ return 0;
+ usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);
+ }
+ return -ETIMEDOUT;
+}
+
+static int hp206c_set_compensation(struct i2c_client *client, bool enabled)
+{
+ int val;
+
+ val = hp206c_read_reg(client, HP206C_REG_PARA);
+ if (val < 0)
+ return val;
+ if (enabled)
+ val |= HP206C_FLAG_CMPS_EN;
+ else
+ val &= ~HP206C_FLAG_CMPS_EN;
+
+ return hp206c_write_reg(client, HP206C_REG_PARA, val);
+}
+
+/* Do a soft reset */
+static int hp206c_soft_reset(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct hp206c_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+
+ ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);
+ if (ret) {
+ dev_err(&client->dev, "Failed to reset device: %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(400, 600);
+
+ ret = hp206c_wait_dev_rdy(indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);
+ return ret;
+ }
+
+ ret = hp206c_set_compensation(client, true);
+ if (ret)
+ dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);
+ return ret;
+}
+
+static int hp206c_conv_and_read(struct iio_dev *indio_dev,
+ u8 conv_cmd, u8 read_cmd,
+ unsigned int sleep_us)
+{
+ int ret;
+ struct hp206c_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+
+ ret = hp206c_wait_dev_rdy(indio_dev);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
+ return ret;
+ }
+
+ ret = i2c_smbus_write_byte(client, conv_cmd);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(sleep_us, sleep_us * 3 / 2);
+
+ ret = hp206c_wait_dev_rdy(indio_dev);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
+ return ret;
+ }
+
+ ret = hp206c_read_20bit(client, read_cmd);
+ if (ret < 0)
+ dev_err(&indio_dev->dev, "Failed read: %d\n", ret);
+
+ return ret;
+}
+
+static int hp206c_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ int ret;
+ struct hp206c_data *data = iio_priv(indio_dev);
+ const struct hp206c_osr_setting *osr_setting;
+ u8 conv_cmd;
+
+ mutex_lock(&data->mutex);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ switch (chan->type) {
+ case IIO_TEMP:
+ *val = hp206c_osr_rates[data->temp_osr_index];
+ ret = IIO_VAL_INT;
+ break;
+
+ case IIO_PRESSURE:
+ *val = hp206c_osr_rates[data->pres_osr_index];
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ break;
+
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_TEMP:
+ osr_setting = &hp206c_osr_settings[data->temp_osr_index];
+ conv_cmd = HP206C_CMD_ADC_CVT |
+ osr_setting->osr_mask |
+ HP206C_CMD_ADC_CVT_CHNL_T;
+ ret = hp206c_conv_and_read(indio_dev,
+ conv_cmd,
+ HP206C_CMD_READ_T,
+ osr_setting->temp_conv_time_us);
+ if (ret >= 0) {
+ /* 20 significant bits are provided.
+ * Extend sign over the rest.
+ */
+ *val = sign_extend32(ret, 19);
+ ret = IIO_VAL_INT;
+ }
+ break;
+
+ case IIO_PRESSURE:
+ osr_setting = &hp206c_osr_settings[data->pres_osr_index];
+ conv_cmd = HP206C_CMD_ADC_CVT |
+ osr_setting->osr_mask |
+ HP206C_CMD_ADC_CVT_CHNL_PT;
+ ret = hp206c_conv_and_read(indio_dev,
+ conv_cmd,
+ HP206C_CMD_READ_P,
+ osr_setting->pres_conv_time_us);
+ if (ret >= 0) {
+ *val = ret;
+ ret = IIO_VAL_INT;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ break;
+
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_TEMP:
+ *val = 0;
+ *val2 = 10000;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+
+ case IIO_PRESSURE:
+ *val = 0;
+ *val2 = 1000;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ mutex_unlock(&data->mutex);
+ return ret;
+}
+
+static int hp206c_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int ret = 0;
+ struct hp206c_data *data = iio_priv(indio_dev);
+
+ if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
+ return -EINVAL;
+ mutex_lock(&data->mutex);
+ switch (chan->type) {
+ case IIO_TEMP:
+ data->temp_osr_index = find_closest_descending(val,
+ hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
+ break;
+ case IIO_PRESSURE:
+ data->pres_osr_index = find_closest_descending(val,
+ hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ mutex_unlock(&data->mutex);
+ return ret;
+}
+
+static const struct iio_chan_spec hp206c_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ },
+ {
+ .type = IIO_PRESSURE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ }
+};
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);
+
+static struct attribute *hp206c_attributes[] = {
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group hp206c_attribute_group = {
+ .attrs = hp206c_attributes,
+};
+
+static const struct iio_info hp206c_info = {
+ .attrs = &hp206c_attribute_group,
+ .read_raw = hp206c_read_raw,
+ .write_raw = hp206c_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int hp206c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *indio_dev;
+ struct hp206c_data *data;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+ dev_err(&client->dev, "Adapter does not support "
+ "all required i2c functionality\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ mutex_init(&data->mutex);
+
+ indio_dev->info = &hp206c_info;
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = hp206c_channels;
+ indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);
+
+ i2c_set_clientdata(client, indio_dev);
+
+ /* Do a soft reset on probe */
+ ret = hp206c_soft_reset(indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);
+ return -ENODEV;
+ }
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id hp206c_id[] = {
+ {"hp206c"},
+ {}
+};
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id hp206c_acpi_match[] = {
+ {"HOP206C", 0},
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);
+#endif
+
+static struct i2c_driver hp206c_driver = {
+ .probe = hp206c_probe,
+ .id_table = hp206c_id,
+ .driver = {
+ .name = "hp206c",
+ .acpi_match_table = ACPI_PTR(hp206c_acpi_match),
+ },
+};
+
+module_i2c_driver(hp206c_driver);
+
+MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");
+MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-exynos.git / commitdiff