diff options
Diffstat (limited to 'drivers/iio/magnetometer/mag3110.c')
| -rw-r--r-- | drivers/iio/magnetometer/mag3110.c | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/drivers/iio/magnetometer/mag3110.c b/drivers/iio/magnetometer/mag3110.c new file mode 100644 index 000000000..57fbe5bfe --- /dev/null +++ b/drivers/iio/magnetometer/mag3110.c @@ -0,0 +1,590 @@ +/* + * mag3110.c - Support for Freescale MAG3110 magnetometer sensor + * + * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> + * + * 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 0x0e) + * + * TODO: irq, user offset, oversampling, continuous mode + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/buffer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/delay.h> + +#define MAG3110_STATUS 0x00 +#define MAG3110_OUT_X 0x01 /* MSB first */ +#define MAG3110_OUT_Y 0x03 +#define MAG3110_OUT_Z 0x05 +#define MAG3110_WHO_AM_I 0x07 +#define MAG3110_SYSMOD 0x08 +#define MAG3110_OFF_X 0x09 /* MSB first */ +#define MAG3110_OFF_Y 0x0b +#define MAG3110_OFF_Z 0x0d +#define MAG3110_DIE_TEMP 0x0f +#define MAG3110_CTRL_REG1 0x10 +#define MAG3110_CTRL_REG2 0x11 + +#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0)) + +#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5)) +#define MAG3110_CTRL_DR_SHIFT 5 +#define MAG3110_CTRL_DR_DEFAULT 0 + +#define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0) + +#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */ +#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */ + +#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */ +#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */ + +#define MAG3110_DEVICE_ID 0xc4 + +/* Each client has this additional data */ +struct mag3110_data { + struct i2c_client *client; + struct mutex lock; + u8 ctrl_reg1; + int sleep_val; + /* Ensure natural alignment of timestamp */ + struct { + __be16 channels[3]; + u8 temperature; + s64 ts __aligned(8); + } scan; +}; + +static int mag3110_request(struct mag3110_data *data) +{ + int ret, tries = 150; + + if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) { + /* trigger measurement */ + ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, + data->ctrl_reg1 | MAG3110_CTRL_TM); + if (ret < 0) + return ret; + } + + while (tries-- > 0) { + ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS); + if (ret < 0) + return ret; + /* wait for data ready */ + if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY) + break; + + if (data->sleep_val <= 20) + usleep_range(data->sleep_val * 250, data->sleep_val * 500); + else + msleep(20); + } + + if (tries < 0) { + dev_err(&data->client->dev, "data not ready\n"); + return -EIO; + } + + return 0; +} + +static int mag3110_read(struct mag3110_data *data, __be16 buf[3]) +{ + int ret; + + mutex_lock(&data->lock); + ret = mag3110_request(data); + if (ret < 0) { + mutex_unlock(&data->lock); + return ret; + } + ret = i2c_smbus_read_i2c_block_data(data->client, + MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf); + mutex_unlock(&data->lock); + + return ret; +} + +static ssize_t mag3110_show_int_plus_micros(char *buf, + const int (*vals)[2], int n) +{ + size_t len = 0; + + while (n-- > 0) + len += scnprintf(buf + len, PAGE_SIZE - len, + "%d.%06d ", vals[n][0], vals[n][1]); + + /* replace trailing space by newline */ + buf[len - 1] = '\n'; + + return len; +} + +static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n, + int val, int val2) +{ + while (n-- > 0) + if (val == vals[n][0] && val2 == vals[n][1]) + return n; + + return -EINVAL; +} + +static const int mag3110_samp_freq[8][2] = { + {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000}, + {1, 250000}, {0, 625000} +}; + +static ssize_t mag3110_show_samp_freq_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8); +} + +static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail); + +static int mag3110_get_samp_freq_index(struct mag3110_data *data, + int val, int val2) +{ + return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val, + val2); +} + +static int mag3110_calculate_sleep(struct mag3110_data *data) +{ + int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT; + + if (mag3110_samp_freq[i][0] > 0) + ret = 1000 / mag3110_samp_freq[i][0]; + else + ret = 1000; + + return ret == 0 ? 1 : ret; +} + +static int mag3110_standby(struct mag3110_data *data) +{ + return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, + data->ctrl_reg1 & ~MAG3110_CTRL_AC); +} + +static int mag3110_wait_standby(struct mag3110_data *data) +{ + int ret, tries = 30; + + /* + * Takes up to 1/ODR to come out of active mode into stby + * Longest expected period is 12.5seconds. + * We'll sleep for 500ms between checks + */ + while (tries-- > 0) { + ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD); + if (ret < 0) { + dev_err(&data->client->dev, "i2c error\n"); + return ret; + } + /* wait for standby */ + if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0) + break; + + msleep_interruptible(500); + } + + if (tries < 0) { + dev_err(&data->client->dev, "device not entering standby mode\n"); + return -EIO; + } + + return 0; +} + +static int mag3110_active(struct mag3110_data *data) +{ + return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, + data->ctrl_reg1); +} + +/* returns >0 if active, 0 if in standby and <0 on error */ +static int mag3110_is_active(struct mag3110_data *data) +{ + int reg; + + reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1); + if (reg < 0) + return reg; + + return reg & MAG3110_CTRL_AC; +} + +static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val) +{ + int ret; + int is_active; + + mutex_lock(&data->lock); + + is_active = mag3110_is_active(data); + if (is_active < 0) { + ret = is_active; + goto fail; + } + + /* config can only be changed when in standby */ + if (is_active > 0) { + ret = mag3110_standby(data); + if (ret < 0) + goto fail; + } + + /* + * After coming out of active we must wait for the part + * to transition to STBY. This can take up to 1 /ODR to occur + */ + ret = mag3110_wait_standby(data); + if (ret < 0) + goto fail; + + ret = i2c_smbus_write_byte_data(data->client, reg, val); + if (ret < 0) + goto fail; + + if (is_active > 0) { + ret = mag3110_active(data); + if (ret < 0) + goto fail; + } + + ret = 0; +fail: + mutex_unlock(&data->lock); + + return ret; +} + +static int mag3110_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mag3110_data *data = iio_priv(indio_dev); + __be16 buffer[3]; + int i, ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + + switch (chan->type) { + case IIO_MAGN: /* in 0.1 uT / LSB */ + ret = mag3110_read(data, buffer); + if (ret < 0) + goto release; + *val = sign_extend32( + be16_to_cpu(buffer[chan->scan_index]), 15); + ret = IIO_VAL_INT; + break; + case IIO_TEMP: /* in 1 C / LSB */ + mutex_lock(&data->lock); + ret = mag3110_request(data); + if (ret < 0) { + mutex_unlock(&data->lock); + goto release; + } + ret = i2c_smbus_read_byte_data(data->client, + MAG3110_DIE_TEMP); + mutex_unlock(&data->lock); + if (ret < 0) + goto release; + *val = sign_extend32(ret, 7); + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + } +release: + iio_device_release_direct_mode(indio_dev); + return ret; + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_MAGN: + *val = 0; + *val2 = 1000; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_TEMP: + *val = 1000; + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_SAMP_FREQ: + i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT; + *val = mag3110_samp_freq[i][0]; + *val2 = mag3110_samp_freq[i][1]; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_CALIBBIAS: + ret = i2c_smbus_read_word_swapped(data->client, + MAG3110_OFF_X + 2 * chan->scan_index); + if (ret < 0) + return ret; + *val = sign_extend32(ret >> 1, 14); + return IIO_VAL_INT; + } + return -EINVAL; +} + +static int mag3110_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct mag3110_data *data = iio_priv(indio_dev); + int rate, ret; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + rate = mag3110_get_samp_freq_index(data, val, val2); + if (rate < 0) { + ret = -EINVAL; + break; + } + data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK + & ~MAG3110_CTRL_AC; + data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT; + data->sleep_val = mag3110_calculate_sleep(data); + if (data->sleep_val < 40) + data->ctrl_reg1 |= MAG3110_CTRL_AC; + + ret = mag3110_change_config(data, MAG3110_CTRL_REG1, + data->ctrl_reg1); + break; + case IIO_CHAN_INFO_CALIBBIAS: + if (val < -10000 || val > 10000) { + ret = -EINVAL; + break; + } + ret = i2c_smbus_write_word_swapped(data->client, + MAG3110_OFF_X + 2 * chan->scan_index, val << 1); + break; + default: + ret = -EINVAL; + break; + } + iio_device_release_direct_mode(indio_dev); + return ret; +} + +static irqreturn_t mag3110_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct mag3110_data *data = iio_priv(indio_dev); + int ret; + + ret = mag3110_read(data, data->scan.channels); + if (ret < 0) + goto done; + + if (test_bit(3, indio_dev->active_scan_mask)) { + ret = i2c_smbus_read_byte_data(data->client, + MAG3110_DIE_TEMP); + if (ret < 0) + goto done; + data->scan.temperature = ret; + } + + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + iio_get_time_ns(indio_dev)); + +done: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +#define MAG3110_CHANNEL(axis, idx) { \ + .type = IIO_MAGN, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_CALIBBIAS), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .scan_index = idx, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_BE, \ + }, \ +} + +static const struct iio_chan_spec mag3110_channels[] = { + MAG3110_CHANNEL(X, 0), + MAG3110_CHANNEL(Y, 1), + MAG3110_CHANNEL(Z, 2), + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 3, + .scan_type = { + .sign = 's', + .realbits = 8, + .storagebits = 8, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(4), +}; + +static struct attribute *mag3110_attributes[] = { + &iio_dev_attr_sampling_frequency_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group mag3110_group = { + .attrs = mag3110_attributes, +}; + +static const struct iio_info mag3110_info = { + .attrs = &mag3110_group, + .read_raw = &mag3110_read_raw, + .write_raw = &mag3110_write_raw, +}; + +static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0}; + +static int mag3110_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct mag3110_data *data; + struct iio_dev *indio_dev; + int ret; + + ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I); + if (ret < 0) + return ret; + if (ret != MAG3110_DEVICE_ID) + 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->lock); + + i2c_set_clientdata(client, indio_dev); + indio_dev->info = &mag3110_info; + indio_dev->name = id->name; + indio_dev->dev.parent = &client->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = mag3110_channels; + indio_dev->num_channels = ARRAY_SIZE(mag3110_channels); + indio_dev->available_scan_masks = mag3110_scan_masks; + + data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT; + data->sleep_val = mag3110_calculate_sleep(data); + if (data->sleep_val < 40) + data->ctrl_reg1 |= MAG3110_CTRL_AC; + + ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2, + MAG3110_CTRL_AUTO_MRST_EN); + if (ret < 0) + goto standby_on_error; + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + mag3110_trigger_handler, NULL); + if (ret < 0) + goto standby_on_error; + + ret = iio_device_register(indio_dev); + if (ret < 0) + goto buffer_cleanup; + return 0; + +buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); +standby_on_error: + mag3110_standby(iio_priv(indio_dev)); + return ret; +} + +static int mag3110_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + mag3110_standby(iio_priv(indio_dev)); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int mag3110_suspend(struct device *dev) +{ + return mag3110_standby(iio_priv(i2c_get_clientdata( + to_i2c_client(dev)))); +} + +static int mag3110_resume(struct device *dev) +{ + struct mag3110_data *data = iio_priv(i2c_get_clientdata( + to_i2c_client(dev))); + + return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, + data->ctrl_reg1); +} + +static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume); +#define MAG3110_PM_OPS (&mag3110_pm_ops) +#else +#define MAG3110_PM_OPS NULL +#endif + +static const struct i2c_device_id mag3110_id[] = { + { "mag3110", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, mag3110_id); + +static const struct of_device_id mag3110_of_match[] = { + { .compatible = "fsl,mag3110" }, + { } +}; +MODULE_DEVICE_TABLE(of, mag3110_of_match); + +static struct i2c_driver mag3110_driver = { + .driver = { + .name = "mag3110", + .of_match_table = mag3110_of_match, + .pm = MAG3110_PM_OPS, + }, + .probe = mag3110_probe, + .remove = mag3110_remove, + .id_table = mag3110_id, +}; +module_i2c_driver(mag3110_driver); + +MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); +MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver"); +MODULE_LICENSE("GPL"); |