| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * mag3110.c - Support for Freescale MAG3110 magnetometer sensor |
| * |
| * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> |
| * |
| * (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> |
| #include <linux/regulator/consumer.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; |
| struct regulator *vdd_reg; |
| struct regulator *vddio_reg; |
| /* 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]), |
| chan->scan_type.realbits - 1); |
| 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, |
| chan->scan_type.realbits - 1); |
| 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; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| data = iio_priv(indio_dev); |
| |
| data->vdd_reg = devm_regulator_get(&client->dev, "vdd"); |
| if (IS_ERR(data->vdd_reg)) |
| return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg), |
| "failed to get VDD regulator!\n"); |
| |
| data->vddio_reg = devm_regulator_get(&client->dev, "vddio"); |
| if (IS_ERR(data->vddio_reg)) |
| return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg), |
| "failed to get VDDIO regulator!\n"); |
| |
| ret = regulator_enable(data->vdd_reg); |
| if (ret) { |
| dev_err(&client->dev, "failed to enable VDD regulator!\n"); |
| return ret; |
| } |
| |
| ret = regulator_enable(data->vddio_reg); |
| if (ret) { |
| dev_err(&client->dev, "failed to enable VDDIO regulator!\n"); |
| goto disable_regulator_vdd; |
| } |
| |
| ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I); |
| if (ret < 0) |
| goto disable_regulators; |
| if (ret != MAG3110_DEVICE_ID) { |
| ret = -ENODEV; |
| goto disable_regulators; |
| } |
| |
| 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->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) |
| goto disable_regulators; |
| |
| 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)); |
| disable_regulators: |
| regulator_disable(data->vddio_reg); |
| disable_regulator_vdd: |
| regulator_disable(data->vdd_reg); |
| |
| return ret; |
| } |
| |
| static void mag3110_remove(struct i2c_client *client) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| struct mag3110_data *data = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| iio_triggered_buffer_cleanup(indio_dev); |
| mag3110_standby(iio_priv(indio_dev)); |
| regulator_disable(data->vddio_reg); |
| regulator_disable(data->vdd_reg); |
| } |
| |
| static int mag3110_suspend(struct device *dev) |
| { |
| struct mag3110_data *data = iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev))); |
| int ret; |
| |
| ret = mag3110_standby(iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev)))); |
| if (ret) |
| return ret; |
| |
| ret = regulator_disable(data->vddio_reg); |
| if (ret) { |
| dev_err(dev, "failed to disable VDDIO regulator\n"); |
| return ret; |
| } |
| |
| ret = regulator_disable(data->vdd_reg); |
| if (ret) { |
| dev_err(dev, "failed to disable VDD regulator\n"); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int mag3110_resume(struct device *dev) |
| { |
| struct mag3110_data *data = iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev))); |
| int ret; |
| |
| ret = regulator_enable(data->vdd_reg); |
| if (ret) { |
| dev_err(dev, "failed to enable VDD regulator\n"); |
| return ret; |
| } |
| |
| ret = regulator_enable(data->vddio_reg); |
| if (ret) { |
| dev_err(dev, "failed to enable VDDIO regulator\n"); |
| regulator_disable(data->vdd_reg); |
| return ret; |
| } |
| |
| return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, |
| data->ctrl_reg1); |
| } |
| |
| static DEFINE_SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, |
| mag3110_resume); |
| |
| 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 = pm_sleep_ptr(&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"); |