diff options
Diffstat (limited to 'drivers/iio/accel/stk8ba50.c')
| -rw-r--r-- | drivers/iio/accel/stk8ba50.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c new file mode 100644 index 000000000..e8087d7ee --- /dev/null +++ b/drivers/iio/accel/stk8ba50.c @@ -0,0 +1,561 @@ +// SPDX-License-Identifier: GPL-2.0-only +/** + * Sensortek STK8BA50 3-Axis Accelerometer + * + * Copyright (c) 2015, Intel Corporation. + * + * STK8BA50 7-bit I2C address: 0x18. + */ + +#include <linux/acpi.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> + +#define STK8BA50_REG_XOUT 0x02 +#define STK8BA50_REG_YOUT 0x04 +#define STK8BA50_REG_ZOUT 0x06 +#define STK8BA50_REG_RANGE 0x0F +#define STK8BA50_REG_BWSEL 0x10 +#define STK8BA50_REG_POWMODE 0x11 +#define STK8BA50_REG_SWRST 0x14 +#define STK8BA50_REG_INTEN2 0x17 +#define STK8BA50_REG_INTMAP2 0x1A + +#define STK8BA50_MODE_NORMAL 0 +#define STK8BA50_MODE_SUSPEND 1 +#define STK8BA50_MODE_POWERBIT BIT(7) +#define STK8BA50_DATA_SHIFT 6 +#define STK8BA50_RESET_CMD 0xB6 +#define STK8BA50_SR_1792HZ_IDX 7 +#define STK8BA50_DREADY_INT_MASK 0x10 +#define STK8BA50_DREADY_INT_MAP 0x81 +#define STK8BA50_ALL_CHANNEL_MASK 7 +#define STK8BA50_ALL_CHANNEL_SIZE 6 + +#define STK8BA50_DRIVER_NAME "stk8ba50" +#define STK8BA50_IRQ_NAME "stk8ba50_event" + +#define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069" + +/* + * The accelerometer has four measurement ranges: + * +/-2g; +/-4g; +/-8g; +/-16g + * + * Acceleration values are 10-bit, 2's complement. + * Scales are calculated as following: + * + * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384 + * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767 + * etc. + * + * Scales are stored in this format: + * { <register value>, <scale value> } + * + * Locally, the range is stored as a table index. + */ +static const struct { + u8 reg_val; + u32 scale_val; +} stk8ba50_scale_table[] = { + {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900} +}; + +/* Sample rates are stored as { <register value>, <Hz value> } */ +static const struct { + u8 reg_val; + u16 samp_freq; +} stk8ba50_samp_freq_table[] = { + {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112}, + {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792} +}; + +/* Used to map scan mask bits to their corresponding channel register. */ +static const int stk8ba50_channel_table[] = { + STK8BA50_REG_XOUT, + STK8BA50_REG_YOUT, + STK8BA50_REG_ZOUT +}; + +struct stk8ba50_data { + struct i2c_client *client; + struct mutex lock; + int range; + u8 sample_rate_idx; + struct iio_trigger *dready_trig; + bool dready_trigger_on; + /* Ensure timestamp is naturally aligned */ + struct { + s16 chans[3]; + s64 timetamp __aligned(8); + } scan; +}; + +#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \ + .type = IIO_ACCEL, \ + .address = reg, \ + .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 = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 10, \ + .storagebits = 16, \ + .shift = STK8BA50_DATA_SHIFT, \ + .endianness = IIO_CPU, \ + }, \ +} + +static const struct iio_chan_spec stk8ba50_channels[] = { + STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X), + STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y), + STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL); + +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792"); + +static struct attribute *stk8ba50_attributes[] = { + &iio_const_attr_in_accel_scale_available.dev_attr.attr, + &iio_const_attr_sampling_frequency_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group stk8ba50_attribute_group = { + .attrs = stk8ba50_attributes +}; + +static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg) +{ + int ret; + struct i2c_client *client = data->client; + + ret = i2c_smbus_read_word_data(client, reg); + if (ret < 0) { + dev_err(&client->dev, "register read failed\n"); + return ret; + } + + return ret; +} + +static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig, + bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct stk8ba50_data *data = iio_priv(indio_dev); + int ret; + + if (state) + ret = i2c_smbus_write_byte_data(data->client, + STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); + else + ret = i2c_smbus_write_byte_data(data->client, + STK8BA50_REG_INTEN2, 0x00); + + if (ret < 0) + dev_err(&data->client->dev, "failed to set trigger state\n"); + else + data->dready_trigger_on = state; + + return ret; +} + +static const struct iio_trigger_ops stk8ba50_trigger_ops = { + .set_trigger_state = stk8ba50_data_rdy_trigger_set_state, +}; + +static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode) +{ + int ret; + u8 masked_reg; + struct i2c_client *client = data->client; + + ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE); + if (ret < 0) + goto exit_err; + + if (mode) + masked_reg = ret | STK8BA50_MODE_POWERBIT; + else + masked_reg = ret & (~STK8BA50_MODE_POWERBIT); + + ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE, + masked_reg); + if (ret < 0) + goto exit_err; + + return ret; + +exit_err: + dev_err(&client->dev, "failed to change sensor mode\n"); + return ret; +} + +static int stk8ba50_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct stk8ba50_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + mutex_lock(&data->lock); + ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); + if (ret < 0) { + mutex_unlock(&data->lock); + return -EINVAL; + } + ret = stk8ba50_read_accel(data, chan->address); + if (ret < 0) { + stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); + mutex_unlock(&data->lock); + return -EINVAL; + } + *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9); + stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); + mutex_unlock(&data->lock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = stk8ba50_scale_table[data->range].scale_val; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = stk8ba50_samp_freq_table + [data->sample_rate_idx].samp_freq; + *val2 = 0; + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static int stk8ba50_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + int ret; + int i; + int index = -1; + struct stk8ba50_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + if (val != 0) + return -EINVAL; + + for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++) + if (val2 == stk8ba50_scale_table[i].scale_val) { + index = i; + break; + } + if (index < 0) + return -EINVAL; + + ret = i2c_smbus_write_byte_data(data->client, + STK8BA50_REG_RANGE, + stk8ba50_scale_table[index].reg_val); + if (ret < 0) + dev_err(&data->client->dev, + "failed to set measurement range\n"); + else + data->range = index; + + return ret; + case IIO_CHAN_INFO_SAMP_FREQ: + for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++) + if (val == stk8ba50_samp_freq_table[i].samp_freq) { + index = i; + break; + } + if (index < 0) + return -EINVAL; + + ret = i2c_smbus_write_byte_data(data->client, + STK8BA50_REG_BWSEL, + stk8ba50_samp_freq_table[index].reg_val); + if (ret < 0) + dev_err(&data->client->dev, + "failed to set sampling rate\n"); + else + data->sample_rate_idx = index; + + return ret; + } + + return -EINVAL; +} + +static const struct iio_info stk8ba50_info = { + .read_raw = stk8ba50_read_raw, + .write_raw = stk8ba50_write_raw, + .attrs = &stk8ba50_attribute_group, +}; + +static irqreturn_t stk8ba50_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct stk8ba50_data *data = iio_priv(indio_dev); + int bit, ret, i = 0; + + mutex_lock(&data->lock); + /* + * Do a bulk read if all channels are requested, + * from 0x02 (XOUT1) to 0x07 (ZOUT2) + */ + if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) { + ret = i2c_smbus_read_i2c_block_data(data->client, + STK8BA50_REG_XOUT, + STK8BA50_ALL_CHANNEL_SIZE, + (u8 *)data->scan.chans); + if (ret < STK8BA50_ALL_CHANNEL_SIZE) { + dev_err(&data->client->dev, "register read failed\n"); + goto err; + } + } else { + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->masklength) { + ret = stk8ba50_read_accel(data, + stk8ba50_channel_table[bit]); + if (ret < 0) + goto err; + + data->scan.chans[i++] = ret; + } + } + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + pf->timestamp); +err: + mutex_unlock(&data->lock); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct stk8ba50_data *data = iio_priv(indio_dev); + + if (data->dready_trigger_on) + iio_trigger_poll(data->dready_trig); + + return IRQ_HANDLED; +} + +static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev) +{ + struct stk8ba50_data *data = iio_priv(indio_dev); + + return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); +} + +static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct stk8ba50_data *data = iio_priv(indio_dev); + + return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); +} + +static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = { + .preenable = stk8ba50_buffer_preenable, + .postdisable = stk8ba50_buffer_postdisable, +}; + +static int stk8ba50_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct iio_dev *indio_dev; + struct stk8ba50_data *data; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) { + dev_err(&client->dev, "iio allocation failed!\n"); + return -ENOMEM; + } + + data = iio_priv(indio_dev); + data->client = client; + i2c_set_clientdata(client, indio_dev); + mutex_init(&data->lock); + + indio_dev->info = &stk8ba50_info; + indio_dev->name = STK8BA50_DRIVER_NAME; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = stk8ba50_channels; + indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels); + + /* Reset all registers on startup */ + ret = i2c_smbus_write_byte_data(client, + STK8BA50_REG_SWRST, STK8BA50_RESET_CMD); + if (ret < 0) { + dev_err(&client->dev, "failed to reset sensor\n"); + goto err_power_off; + } + + /* The default range is +/-2g */ + data->range = 0; + + /* The default sampling rate is 1792 Hz (maximum) */ + data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX; + + /* Set up interrupts */ + ret = i2c_smbus_write_byte_data(client, + STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); + if (ret < 0) { + dev_err(&client->dev, "failed to set up interrupts\n"); + goto err_power_off; + } + ret = i2c_smbus_write_byte_data(client, + STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP); + if (ret < 0) { + dev_err(&client->dev, "failed to set up interrupts\n"); + goto err_power_off; + } + + if (client->irq > 0) { + ret = devm_request_threaded_irq(&client->dev, client->irq, + stk8ba50_data_rdy_trig_poll, + NULL, + IRQF_TRIGGER_RISING | + IRQF_ONESHOT, + STK8BA50_IRQ_NAME, + indio_dev); + if (ret < 0) { + dev_err(&client->dev, "request irq %d failed\n", + client->irq); + goto err_power_off; + } + + data->dready_trig = devm_iio_trigger_alloc(&client->dev, + "%s-dev%d", + indio_dev->name, + indio_dev->id); + if (!data->dready_trig) { + ret = -ENOMEM; + goto err_power_off; + } + + data->dready_trig->dev.parent = &client->dev; + data->dready_trig->ops = &stk8ba50_trigger_ops; + iio_trigger_set_drvdata(data->dready_trig, indio_dev); + ret = iio_trigger_register(data->dready_trig); + if (ret) { + dev_err(&client->dev, "iio trigger register failed\n"); + goto err_power_off; + } + } + + ret = iio_triggered_buffer_setup(indio_dev, + iio_pollfunc_store_time, + stk8ba50_trigger_handler, + &stk8ba50_buffer_setup_ops); + if (ret < 0) { + dev_err(&client->dev, "iio triggered buffer setup failed\n"); + goto err_trigger_unregister; + } + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, "device_register failed\n"); + goto err_buffer_cleanup; + } + + return ret; + +err_buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); +err_trigger_unregister: + if (data->dready_trig) + iio_trigger_unregister(data->dready_trig); +err_power_off: + stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); + return ret; +} + +static int stk8ba50_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct stk8ba50_data *data = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + + if (data->dready_trig) + iio_trigger_unregister(data->dready_trig); + + return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); +} + +#ifdef CONFIG_PM_SLEEP +static int stk8ba50_suspend(struct device *dev) +{ + struct stk8ba50_data *data; + + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + + return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); +} + +static int stk8ba50_resume(struct device *dev) +{ + struct stk8ba50_data *data; + + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + + return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); +} + +static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume); + +#define STK8BA50_PM_OPS (&stk8ba50_pm_ops) +#else +#define STK8BA50_PM_OPS NULL +#endif + +static const struct i2c_device_id stk8ba50_i2c_id[] = { + {"stk8ba50", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id); + +static const struct acpi_device_id stk8ba50_acpi_id[] = { + {"STK8BA50", 0}, + {} +}; + +MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id); + +static struct i2c_driver stk8ba50_driver = { + .driver = { + .name = "stk8ba50", + .pm = STK8BA50_PM_OPS, + .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id), + }, + .probe = stk8ba50_probe, + .remove = stk8ba50_remove, + .id_table = stk8ba50_i2c_id, +}; + +module_i2c_driver(stk8ba50_driver); + +MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); +MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver"); +MODULE_LICENSE("GPL v2"); |