| /* Copyright (C) 2010 Texas Instruments |
| Author: Shubhrajyoti Datta <shubhrajyoti@ti.com> |
| Acknowledgement: Jonathan Cameron <jic23@kernel.org> for valuable inputs. |
| |
| Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>. |
| |
| 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., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #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 HMC5843_CONFIG_REG_A 0x00 |
| #define HMC5843_CONFIG_REG_B 0x01 |
| #define HMC5843_MODE_REG 0x02 |
| #define HMC5843_DATA_OUT_MSB_REGS 0x03 |
| #define HMC5843_STATUS_REG 0x09 |
| #define HMC5843_ID_REG 0x0a |
| |
| enum hmc5843_ids { |
| HMC5843_ID, |
| HMC5883_ID, |
| HMC5883L_ID, |
| }; |
| |
| /* |
| * Range gain settings in (+-)Ga |
| * Beware: HMC5843 and HMC5883 have different recommended sensor field |
| * ranges; default corresponds to +-1.0 Ga and +-1.3 Ga, respectively |
| */ |
| #define HMC5843_RANGE_GAIN_OFFSET 0x05 |
| #define HMC5843_RANGE_GAIN_DEFAULT 0x01 |
| #define HMC5843_RANGE_GAINS 8 |
| |
| /* Device status */ |
| #define HMC5843_DATA_READY 0x01 |
| #define HMC5843_DATA_OUTPUT_LOCK 0x02 |
| |
| /* Mode register configuration */ |
| #define HMC5843_MODE_CONVERSION_CONTINUOUS 0x00 |
| #define HMC5843_MODE_CONVERSION_SINGLE 0x01 |
| #define HMC5843_MODE_IDLE 0x02 |
| #define HMC5843_MODE_SLEEP 0x03 |
| #define HMC5843_MODE_MASK 0x03 |
| |
| /* |
| * HMC5843: Minimum data output rate |
| * HMC5883: Typical data output rate |
| */ |
| #define HMC5843_RATE_OFFSET 0x02 |
| #define HMC5843_RATE_DEFAULT 0x04 |
| #define HMC5843_RATES 7 |
| |
| /* Device measurement configuration */ |
| #define HMC5843_MEAS_CONF_NORMAL 0x00 |
| #define HMC5843_MEAS_CONF_POSITIVE_BIAS 0x01 |
| #define HMC5843_MEAS_CONF_NEGATIVE_BIAS 0x02 |
| #define HMC5843_MEAS_CONF_MASK 0x03 |
| |
| /* Scaling factors: 10000000/Gain */ |
| static const int hmc5843_regval_to_nanoscale[HMC5843_RANGE_GAINS] = { |
| 6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714 |
| }; |
| |
| static const int hmc5883_regval_to_nanoscale[HMC5843_RANGE_GAINS] = { |
| 7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662 |
| }; |
| |
| static const int hmc5883l_regval_to_nanoscale[HMC5843_RANGE_GAINS] = { |
| 7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478 |
| }; |
| |
| /* |
| * From the datasheet: |
| * Value | HMC5843 | HMC5883/HMC5883L |
| * | Data output rate (Hz) | Data output rate (Hz) |
| * 0 | 0.5 | 0.75 |
| * 1 | 1 | 1.5 |
| * 2 | 2 | 3 |
| * 3 | 5 | 7.5 |
| * 4 | 10 (default) | 15 |
| * 5 | 20 | 30 |
| * 6 | 50 | 75 |
| * 7 | Not used | Not used |
| */ |
| static const int hmc5843_regval_to_samp_freq[7][2] = { |
| {0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0} |
| }; |
| |
| static const int hmc5883_regval_to_samp_freq[7][2] = { |
| {0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0}, |
| {75, 0} |
| }; |
| |
| /* Describe chip variants */ |
| struct hmc5843_chip_info { |
| const struct iio_chan_spec *channels; |
| const int (*regval_to_samp_freq)[2]; |
| const int *regval_to_nanoscale; |
| }; |
| |
| /* Each client has this additional data */ |
| struct hmc5843_data { |
| struct i2c_client *client; |
| struct mutex lock; |
| u8 rate; |
| u8 meas_conf; |
| u8 operating_mode; |
| u8 range; |
| const struct hmc5843_chip_info *variant; |
| __be16 buffer[8]; /* 3x 16-bit channels + padding + 64-bit timestamp */ |
| }; |
| |
| /* The lower two bits contain the current conversion mode */ |
| static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode) |
| { |
| int ret; |
| |
| mutex_lock(&data->lock); |
| ret = i2c_smbus_write_byte_data(data->client, HMC5843_MODE_REG, |
| operating_mode & HMC5843_MODE_MASK); |
| if (ret >= 0) |
| data->operating_mode = operating_mode; |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| static int hmc5843_wait_measurement(struct hmc5843_data *data) |
| { |
| s32 result; |
| int tries = 150; |
| |
| while (tries-- > 0) { |
| result = i2c_smbus_read_byte_data(data->client, |
| HMC5843_STATUS_REG); |
| if (result < 0) |
| return result; |
| if (result & HMC5843_DATA_READY) |
| break; |
| msleep(20); |
| } |
| |
| if (tries < 0) { |
| dev_err(&data->client->dev, "data not ready\n"); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| /* Return the measurement value from the specified channel */ |
| static int hmc5843_read_measurement(struct hmc5843_data *data, |
| int idx, int *val) |
| { |
| s32 result; |
| __be16 values[3]; |
| |
| mutex_lock(&data->lock); |
| result = hmc5843_wait_measurement(data); |
| if (result < 0) { |
| mutex_unlock(&data->lock); |
| return result; |
| } |
| result = i2c_smbus_read_i2c_block_data(data->client, |
| HMC5843_DATA_OUT_MSB_REGS, sizeof(values), (u8 *) values); |
| mutex_unlock(&data->lock); |
| if (result < 0) |
| return -EINVAL; |
| |
| *val = sign_extend32(be16_to_cpu(values[idx]), 15); |
| return IIO_VAL_INT; |
| } |
| |
| /* |
| * API for setting the measurement configuration to |
| * Normal, Positive bias and Negative bias |
| * |
| * From the datasheet: |
| * 0 - Normal measurement configuration (default): In normal measurement |
| * configuration the device follows normal measurement flow. Pins BP |
| * and BN are left floating and high impedance. |
| * |
| * 1 - Positive bias configuration: In positive bias configuration, a |
| * positive current is forced across the resistive load on pins BP |
| * and BN. |
| * |
| * 2 - Negative bias configuration. In negative bias configuration, a |
| * negative current is forced across the resistive load on pins BP |
| * and BN. |
| * |
| */ |
| static s32 hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf) |
| { |
| int ret; |
| |
| mutex_lock(&data->lock); |
| ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A, |
| (meas_conf & HMC5843_MEAS_CONF_MASK) | |
| (data->rate << HMC5843_RATE_OFFSET)); |
| if (ret >= 0) |
| data->meas_conf = meas_conf; |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| static ssize_t hmc5843_show_measurement_configuration(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); |
| return sprintf(buf, "%d\n", data->meas_conf); |
| } |
| |
| static ssize_t hmc5843_set_measurement_configuration(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, |
| size_t count) |
| { |
| struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); |
| unsigned long meas_conf = 0; |
| int ret; |
| |
| ret = kstrtoul(buf, 10, &meas_conf); |
| if (ret) |
| return ret; |
| if (meas_conf >= HMC5843_MEAS_CONF_MASK) |
| return -EINVAL; |
| |
| ret = hmc5843_set_meas_conf(data, meas_conf); |
| |
| return (ret < 0) ? ret : count; |
| } |
| |
| static IIO_DEVICE_ATTR(meas_conf, |
| S_IWUSR | S_IRUGO, |
| hmc5843_show_measurement_configuration, |
| hmc5843_set_measurement_configuration, |
| 0); |
| |
| static ssize_t hmc5843_show_samp_freq_avail(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); |
| size_t len = 0; |
| int i; |
| |
| for (i = 0; i < HMC5843_RATES; i++) |
| len += scnprintf(buf + len, PAGE_SIZE - len, |
| "%d.%d ", data->variant->regval_to_samp_freq[i][0], |
| data->variant->regval_to_samp_freq[i][1]); |
| |
| /* replace trailing space by newline */ |
| buf[len - 1] = '\n'; |
| |
| return len; |
| } |
| |
| static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_samp_freq_avail); |
| |
| static int hmc5843_set_samp_freq(struct hmc5843_data *data, u8 rate) |
| { |
| int ret; |
| |
| mutex_lock(&data->lock); |
| ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A, |
| data->meas_conf | (rate << HMC5843_RATE_OFFSET)); |
| if (ret >= 0) |
| data->rate = rate; |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| static int hmc5843_get_samp_freq_index(struct hmc5843_data *data, |
| int val, int val2) |
| { |
| int i; |
| |
| for (i = 0; i < HMC5843_RATES; i++) |
| if (val == data->variant->regval_to_samp_freq[i][0] && |
| val2 == data->variant->regval_to_samp_freq[i][1]) |
| return i; |
| |
| return -EINVAL; |
| } |
| |
| static int hmc5843_set_range_gain(struct hmc5843_data *data, u8 range) |
| { |
| int ret; |
| |
| mutex_lock(&data->lock); |
| ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_B, |
| range << HMC5843_RANGE_GAIN_OFFSET); |
| if (ret >= 0) |
| data->range = range; |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| static ssize_t hmc5843_show_scale_avail(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev)); |
| |
| size_t len = 0; |
| int i; |
| |
| for (i = 0; i < HMC5843_RANGE_GAINS; i++) |
| len += scnprintf(buf + len, PAGE_SIZE - len, |
| "0.%09d ", data->variant->regval_to_nanoscale[i]); |
| |
| /* replace trailing space by newline */ |
| buf[len - 1] = '\n'; |
| |
| return len; |
| } |
| |
| static IIO_DEVICE_ATTR(scale_available, S_IRUGO, |
| hmc5843_show_scale_avail, NULL, 0); |
| |
| static int hmc5843_get_scale_index(struct hmc5843_data *data, int val, int val2) |
| { |
| int i; |
| |
| if (val != 0) |
| return -EINVAL; |
| |
| for (i = 0; i < HMC5843_RANGE_GAINS; i++) |
| if (val2 == data->variant->regval_to_nanoscale[i]) |
| return i; |
| |
| return -EINVAL; |
| } |
| |
| static int hmc5843_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| return hmc5843_read_measurement(data, chan->scan_index, val); |
| case IIO_CHAN_INFO_SCALE: |
| *val = 0; |
| *val2 = data->variant->regval_to_nanoscale[data->range]; |
| return IIO_VAL_INT_PLUS_NANO; |
| case IIO_CHAN_INFO_SAMP_FREQ: |
| *val = data->variant->regval_to_samp_freq[data->rate][0]; |
| *val2 = data->variant->regval_to_samp_freq[data->rate][1]; |
| return IIO_VAL_INT_PLUS_MICRO; |
| } |
| return -EINVAL; |
| } |
| |
| static int hmc5843_write_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int val, int val2, long mask) |
| { |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| int rate, range; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_SAMP_FREQ: |
| rate = hmc5843_get_samp_freq_index(data, val, val2); |
| if (rate < 0) |
| return -EINVAL; |
| |
| return hmc5843_set_samp_freq(data, rate); |
| case IIO_CHAN_INFO_SCALE: |
| range = hmc5843_get_scale_index(data, val, val2); |
| if (range < 0) |
| return -EINVAL; |
| |
| return hmc5843_set_range_gain(data, range); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, long mask) |
| { |
| switch (mask) { |
| case IIO_CHAN_INFO_SAMP_FREQ: |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_CHAN_INFO_SCALE: |
| return IIO_VAL_INT_PLUS_NANO; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static irqreturn_t hmc5843_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct hmc5843_data *data = iio_priv(indio_dev); |
| int ret; |
| |
| mutex_lock(&data->lock); |
| ret = hmc5843_wait_measurement(data); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| goto done; |
| } |
| |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| HMC5843_DATA_OUT_MSB_REGS, 3 * sizeof(__be16), |
| (u8 *) data->buffer); |
| mutex_unlock(&data->lock); |
| if (ret < 0) |
| goto done; |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, |
| iio_get_time_ns()); |
| |
| done: |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| #define HMC5843_CHANNEL(axis, idx) \ |
| { \ |
| .type = IIO_MAGN, \ |
| .modified = 1, \ |
| .channel2 = IIO_MOD_##axis, \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ |
| BIT(IIO_CHAN_INFO_SAMP_FREQ), \ |
| .scan_index = idx, \ |
| .scan_type = IIO_ST('s', 16, 16, IIO_BE), \ |
| } |
| |
| static const struct iio_chan_spec hmc5843_channels[] = { |
| HMC5843_CHANNEL(X, 0), |
| HMC5843_CHANNEL(Y, 1), |
| HMC5843_CHANNEL(Z, 2), |
| IIO_CHAN_SOFT_TIMESTAMP(3), |
| }; |
| |
| /* Beware: Y and Z are exchanged on HMC5883 */ |
| static const struct iio_chan_spec hmc5883_channels[] = { |
| HMC5843_CHANNEL(X, 0), |
| HMC5843_CHANNEL(Z, 1), |
| HMC5843_CHANNEL(Y, 2), |
| IIO_CHAN_SOFT_TIMESTAMP(3), |
| }; |
| |
| static struct attribute *hmc5843_attributes[] = { |
| &iio_dev_attr_meas_conf.dev_attr.attr, |
| &iio_dev_attr_scale_available.dev_attr.attr, |
| &iio_dev_attr_sampling_frequency_available.dev_attr.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group hmc5843_group = { |
| .attrs = hmc5843_attributes, |
| }; |
| |
| static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = { |
| [HMC5843_ID] = { |
| .channels = hmc5843_channels, |
| .regval_to_samp_freq = hmc5843_regval_to_samp_freq, |
| .regval_to_nanoscale = hmc5843_regval_to_nanoscale, |
| }, |
| [HMC5883_ID] = { |
| .channels = hmc5883_channels, |
| .regval_to_samp_freq = hmc5883_regval_to_samp_freq, |
| .regval_to_nanoscale = hmc5883_regval_to_nanoscale, |
| }, |
| [HMC5883L_ID] = { |
| .channels = hmc5883_channels, |
| .regval_to_samp_freq = hmc5883_regval_to_samp_freq, |
| .regval_to_nanoscale = hmc5883l_regval_to_nanoscale, |
| }, |
| }; |
| |
| static int hmc5843_init(struct hmc5843_data *data) |
| { |
| int ret; |
| u8 id[3]; |
| |
| ret = i2c_smbus_read_i2c_block_data(data->client, HMC5843_ID_REG, |
| sizeof(id), id); |
| if (ret < 0) |
| return ret; |
| if (id[0] != 'H' || id[1] != '4' || id[2] != '3') { |
| dev_err(&data->client->dev, "no HMC5843/5883/5883L sensor\n"); |
| return -ENODEV; |
| } |
| |
| ret = hmc5843_set_meas_conf(data, HMC5843_MEAS_CONF_NORMAL); |
| if (ret < 0) |
| return ret; |
| ret = hmc5843_set_samp_freq(data, HMC5843_RATE_DEFAULT); |
| if (ret < 0) |
| return ret; |
| ret = hmc5843_set_range_gain(data, HMC5843_RANGE_GAIN_DEFAULT); |
| if (ret < 0) |
| return ret; |
| return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS); |
| } |
| |
| static const struct iio_info hmc5843_info = { |
| .attrs = &hmc5843_group, |
| .read_raw = &hmc5843_read_raw, |
| .write_raw = &hmc5843_write_raw, |
| .write_raw_get_fmt = &hmc5843_write_raw_get_fmt, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static const unsigned long hmc5843_scan_masks[] = {0x7, 0}; |
| |
| static int hmc5843_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct hmc5843_data *data; |
| struct iio_dev *indio_dev; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| if (indio_dev == NULL) |
| return -ENOMEM; |
| |
| /* default settings at probe */ |
| data = iio_priv(indio_dev); |
| data->client = client; |
| data->variant = &hmc5843_chip_info_tbl[id->driver_data]; |
| mutex_init(&data->lock); |
| |
| i2c_set_clientdata(client, indio_dev); |
| indio_dev->info = &hmc5843_info; |
| indio_dev->name = id->name; |
| indio_dev->dev.parent = &client->dev; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = data->variant->channels; |
| indio_dev->num_channels = 4; |
| indio_dev->available_scan_masks = hmc5843_scan_masks; |
| |
| ret = hmc5843_init(data); |
| if (ret < 0) |
| return ret; |
| |
| ret = iio_triggered_buffer_setup(indio_dev, NULL, |
| hmc5843_trigger_handler, NULL); |
| if (ret < 0) |
| return ret; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret < 0) |
| goto buffer_cleanup; |
| |
| return 0; |
| |
| buffer_cleanup: |
| iio_triggered_buffer_cleanup(indio_dev); |
| return ret; |
| } |
| |
| static int hmc5843_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); |
| |
| /* sleep mode to save power */ |
| hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int hmc5843_suspend(struct device *dev) |
| { |
| struct hmc5843_data *data = iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev))); |
| |
| return hmc5843_set_mode(data, HMC5843_MODE_SLEEP); |
| } |
| |
| static int hmc5843_resume(struct device *dev) |
| { |
| struct hmc5843_data *data = iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev))); |
| |
| return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS); |
| } |
| |
| static SIMPLE_DEV_PM_OPS(hmc5843_pm_ops, hmc5843_suspend, hmc5843_resume); |
| #define HMC5843_PM_OPS (&hmc5843_pm_ops) |
| #else |
| #define HMC5843_PM_OPS NULL |
| #endif |
| |
| static const struct i2c_device_id hmc5843_id[] = { |
| { "hmc5843", HMC5843_ID }, |
| { "hmc5883", HMC5883_ID }, |
| { "hmc5883l", HMC5883L_ID }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, hmc5843_id); |
| |
| static struct i2c_driver hmc5843_driver = { |
| .driver = { |
| .name = "hmc5843", |
| .pm = HMC5843_PM_OPS, |
| }, |
| .id_table = hmc5843_id, |
| .probe = hmc5843_probe, |
| .remove = hmc5843_remove, |
| }; |
| module_i2c_driver(hmc5843_driver); |
| |
| MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com>"); |
| MODULE_DESCRIPTION("HMC5843/5883/5883L driver"); |
| MODULE_LICENSE("GPL"); |