| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Sensortek STK8312 3-Axis Accelerometer |
| * |
| * Copyright (c) 2015, Intel Corporation. |
| * |
| * IIO driver for STK8312; 7-bit I2C address: 0x3D. |
| */ |
| |
| #include <linux/i2c.h> |
| #include <linux/interrupt.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/delay.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 STK8312_REG_XOUT 0x00 |
| #define STK8312_REG_YOUT 0x01 |
| #define STK8312_REG_ZOUT 0x02 |
| #define STK8312_REG_INTSU 0x06 |
| #define STK8312_REG_MODE 0x07 |
| #define STK8312_REG_SR 0x08 |
| #define STK8312_REG_STH 0x13 |
| #define STK8312_REG_RESET 0x20 |
| #define STK8312_REG_AFECTRL 0x24 |
| #define STK8312_REG_OTPADDR 0x3D |
| #define STK8312_REG_OTPDATA 0x3E |
| #define STK8312_REG_OTPCTRL 0x3F |
| |
| #define STK8312_MODE_ACTIVE BIT(0) |
| #define STK8312_MODE_STANDBY 0x00 |
| #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */ |
| #define STK8312_DREADY_BIT BIT(4) |
| #define STK8312_RNG_6G 1 |
| #define STK8312_RNG_SHIFT 6 |
| #define STK8312_RNG_MASK GENMASK(7, 6) |
| #define STK8312_SR_MASK GENMASK(2, 0) |
| #define STK8312_SR_400HZ_IDX 0 |
| #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0) |
| #define STK8312_ALL_CHANNEL_SIZE 3 |
| |
| #define STK8312_DRIVER_NAME "stk8312" |
| #define STK8312_IRQ_NAME "stk8312_event" |
| |
| /* |
| * The accelerometer has two measurement ranges: |
| * |
| * -6g - +6g (8-bit, signed) |
| * -16g - +16g (8-bit, signed) |
| * |
| * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616 |
| * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311 |
| */ |
| #define STK8312_SCALE_AVAIL "0.4616 1.2311" |
| |
| static const int stk8312_scale_table[][2] = { |
| {0, 461600}, {1, 231100} |
| }; |
| |
| static const struct { |
| int val; |
| int val2; |
| } stk8312_samp_freq_table[] = { |
| {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0}, |
| {12, 500000}, {6, 250000}, {3, 125000} |
| }; |
| |
| #define STK8312_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 = 8, \ |
| .storagebits = 8, \ |
| .endianness = IIO_CPU, \ |
| }, \ |
| } |
| |
| static const struct iio_chan_spec stk8312_channels[] = { |
| STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X), |
| STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y), |
| STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z), |
| IIO_CHAN_SOFT_TIMESTAMP(3), |
| }; |
| |
| struct stk8312_data { |
| struct i2c_client *client; |
| struct mutex lock; |
| u8 range; |
| u8 sample_rate_idx; |
| u8 mode; |
| struct iio_trigger *dready_trig; |
| bool dready_trigger_on; |
| /* Ensure timestamp is naturally aligned */ |
| struct { |
| s8 chans[3]; |
| s64 timestamp __aligned(8); |
| } scan; |
| }; |
| |
| static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); |
| |
| static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400"); |
| |
| static struct attribute *stk8312_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 stk8312_attribute_group = { |
| .attrs = stk8312_attributes |
| }; |
| |
| static int stk8312_otp_init(struct stk8312_data *data) |
| { |
| int ret; |
| int count = 10; |
| struct i2c_client *client = data->client; |
| |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70); |
| if (ret < 0) |
| goto exit_err; |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02); |
| if (ret < 0) |
| goto exit_err; |
| |
| do { |
| usleep_range(1000, 5000); |
| ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL); |
| if (ret < 0) |
| goto exit_err; |
| count--; |
| } while (!(ret & BIT(7)) && count > 0); |
| |
| if (count == 0) { |
| ret = -ETIMEDOUT; |
| goto exit_err; |
| } |
| |
| ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA); |
| if (ret == 0) |
| ret = -EINVAL; |
| if (ret < 0) |
| goto exit_err; |
| |
| ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret); |
| if (ret < 0) |
| goto exit_err; |
| msleep(150); |
| |
| return 0; |
| |
| exit_err: |
| dev_err(&client->dev, "failed to initialize sensor\n"); |
| return ret; |
| } |
| |
| static int stk8312_set_mode(struct stk8312_data *data, u8 mode) |
| { |
| int ret; |
| struct i2c_client *client = data->client; |
| |
| if (mode == data->mode) |
| return 0; |
| |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode); |
| if (ret < 0) { |
| dev_err(&client->dev, "failed to change sensor mode\n"); |
| return ret; |
| } |
| |
| data->mode = mode; |
| if (mode & STK8312_MODE_ACTIVE) { |
| /* Need to run OTP sequence before entering active mode */ |
| usleep_range(1000, 5000); |
| ret = stk8312_otp_init(data); |
| } |
| |
| return ret; |
| } |
| |
| static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask) |
| { |
| int ret; |
| u8 mode; |
| struct i2c_client *client = data->client; |
| |
| mode = data->mode; |
| /* We need to go in standby mode to modify registers */ |
| ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); |
| if (ret < 0) |
| return ret; |
| |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask); |
| if (ret < 0) { |
| dev_err(&client->dev, "failed to set interrupts\n"); |
| stk8312_set_mode(data, mode); |
| return ret; |
| } |
| |
| return stk8312_set_mode(data, mode); |
| } |
| |
| static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig, |
| bool state) |
| { |
| struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); |
| struct stk8312_data *data = iio_priv(indio_dev); |
| int ret; |
| |
| if (state) |
| ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT); |
| else |
| ret = stk8312_set_interrupts(data, 0x00); |
| |
| if (ret < 0) { |
| dev_err(&data->client->dev, "failed to set trigger state\n"); |
| return ret; |
| } |
| |
| data->dready_trigger_on = state; |
| |
| return 0; |
| } |
| |
| static const struct iio_trigger_ops stk8312_trigger_ops = { |
| .set_trigger_state = stk8312_data_rdy_trigger_set_state, |
| }; |
| |
| static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate) |
| { |
| int ret; |
| u8 masked_reg; |
| u8 mode; |
| struct i2c_client *client = data->client; |
| |
| if (rate == data->sample_rate_idx) |
| return 0; |
| |
| mode = data->mode; |
| /* We need to go in standby mode to modify registers */ |
| ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); |
| if (ret < 0) |
| return ret; |
| |
| ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR); |
| if (ret < 0) |
| goto err_activate; |
| |
| masked_reg = (ret & (~STK8312_SR_MASK)) | rate; |
| |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg); |
| if (ret < 0) |
| goto err_activate; |
| |
| data->sample_rate_idx = rate; |
| |
| return stk8312_set_mode(data, mode); |
| |
| err_activate: |
| dev_err(&client->dev, "failed to set sampling rate\n"); |
| stk8312_set_mode(data, mode); |
| |
| return ret; |
| } |
| |
| static int stk8312_set_range(struct stk8312_data *data, u8 range) |
| { |
| int ret; |
| u8 masked_reg; |
| u8 mode; |
| struct i2c_client *client = data->client; |
| |
| if (range != 1 && range != 2) |
| return -EINVAL; |
| else if (range == data->range) |
| return 0; |
| |
| mode = data->mode; |
| /* We need to go in standby mode to modify registers */ |
| ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); |
| if (ret < 0) |
| return ret; |
| |
| ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH); |
| if (ret < 0) |
| goto err_activate; |
| |
| masked_reg = ret & (~STK8312_RNG_MASK); |
| masked_reg |= range << STK8312_RNG_SHIFT; |
| |
| ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg); |
| if (ret < 0) |
| goto err_activate; |
| |
| data->range = range; |
| |
| return stk8312_set_mode(data, mode); |
| |
| err_activate: |
| dev_err(&client->dev, "failed to change sensor range\n"); |
| stk8312_set_mode(data, mode); |
| |
| return ret; |
| } |
| |
| static int stk8312_read_accel(struct stk8312_data *data, u8 address) |
| { |
| int ret; |
| struct i2c_client *client = data->client; |
| |
| if (address > 2) |
| return -EINVAL; |
| |
| ret = i2c_smbus_read_byte_data(client, address); |
| if (ret < 0) |
| dev_err(&client->dev, "register read failed\n"); |
| |
| return ret; |
| } |
| |
| static int stk8312_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct stk8312_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 = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| return ret; |
| } |
| ret = stk8312_read_accel(data, chan->address); |
| if (ret < 0) { |
| stk8312_set_mode(data, |
| data->mode & (~STK8312_MODE_ACTIVE)); |
| mutex_unlock(&data->lock); |
| return ret; |
| } |
| *val = sign_extend32(ret, chan->scan_type.realbits - 1); |
| ret = stk8312_set_mode(data, |
| data->mode & (~STK8312_MODE_ACTIVE)); |
| mutex_unlock(&data->lock); |
| if (ret < 0) |
| return ret; |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| *val = stk8312_scale_table[data->range - 1][0]; |
| *val2 = stk8312_scale_table[data->range - 1][1]; |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_CHAN_INFO_SAMP_FREQ: |
| *val = stk8312_samp_freq_table[data->sample_rate_idx].val; |
| *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2; |
| return IIO_VAL_INT_PLUS_MICRO; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int stk8312_write_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int val, int val2, long mask) |
| { |
| int i; |
| int index = -1; |
| int ret; |
| struct stk8312_data *data = iio_priv(indio_dev); |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_SCALE: |
| for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++) |
| if (val == stk8312_scale_table[i][0] && |
| val2 == stk8312_scale_table[i][1]) { |
| index = i + 1; |
| break; |
| } |
| if (index < 0) |
| return -EINVAL; |
| |
| mutex_lock(&data->lock); |
| ret = stk8312_set_range(data, index); |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| case IIO_CHAN_INFO_SAMP_FREQ: |
| for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++) |
| if (val == stk8312_samp_freq_table[i].val && |
| val2 == stk8312_samp_freq_table[i].val2) { |
| index = i; |
| break; |
| } |
| if (index < 0) |
| return -EINVAL; |
| mutex_lock(&data->lock); |
| ret = stk8312_set_sample_rate(data, index); |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static const struct iio_info stk8312_info = { |
| .read_raw = stk8312_read_raw, |
| .write_raw = stk8312_write_raw, |
| .attrs = &stk8312_attribute_group, |
| }; |
| |
| static irqreturn_t stk8312_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct stk8312_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 0x00 (XOUT) to 0x02 (ZOUT) |
| */ |
| if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) { |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| STK8312_REG_XOUT, |
| STK8312_ALL_CHANNEL_SIZE, |
| data->scan.chans); |
| if (ret < STK8312_ALL_CHANNEL_SIZE) { |
| dev_err(&data->client->dev, "register read failed\n"); |
| mutex_unlock(&data->lock); |
| goto err; |
| } |
| } else { |
| for_each_set_bit(bit, indio_dev->active_scan_mask, |
| indio_dev->masklength) { |
| ret = stk8312_read_accel(data, bit); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| goto err; |
| } |
| data->scan.chans[i++] = ret; |
| } |
| } |
| mutex_unlock(&data->lock); |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, |
| pf->timestamp); |
| err: |
| iio_trigger_notify_done(indio_dev->trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private) |
| { |
| struct iio_dev *indio_dev = private; |
| struct stk8312_data *data = iio_priv(indio_dev); |
| |
| if (data->dready_trigger_on) |
| iio_trigger_poll(data->dready_trig); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int stk8312_buffer_preenable(struct iio_dev *indio_dev) |
| { |
| struct stk8312_data *data = iio_priv(indio_dev); |
| |
| return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); |
| } |
| |
| static int stk8312_buffer_postdisable(struct iio_dev *indio_dev) |
| { |
| struct stk8312_data *data = iio_priv(indio_dev); |
| |
| return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); |
| } |
| |
| static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = { |
| .preenable = stk8312_buffer_preenable, |
| .postdisable = stk8312_buffer_postdisable, |
| }; |
| |
| static int stk8312_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| int ret; |
| struct iio_dev *indio_dev; |
| struct stk8312_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 = &stk8312_info; |
| indio_dev->name = STK8312_DRIVER_NAME; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = stk8312_channels; |
| indio_dev->num_channels = ARRAY_SIZE(stk8312_channels); |
| |
| /* A software reset is recommended at power-on */ |
| ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00); |
| if (ret < 0) { |
| dev_err(&client->dev, "failed to reset sensor\n"); |
| return ret; |
| } |
| data->sample_rate_idx = STK8312_SR_400HZ_IDX; |
| ret = stk8312_set_range(data, STK8312_RNG_6G); |
| if (ret < 0) |
| return ret; |
| |
| ret = stk8312_set_mode(data, |
| STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE); |
| if (ret < 0) |
| return ret; |
| |
| if (client->irq > 0) { |
| ret = devm_request_threaded_irq(&client->dev, client->irq, |
| stk8312_data_rdy_trig_poll, |
| NULL, |
| IRQF_TRIGGER_RISING | |
| IRQF_ONESHOT, |
| STK8312_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, |
| iio_device_id(indio_dev)); |
| if (!data->dready_trig) { |
| ret = -ENOMEM; |
| goto err_power_off; |
| } |
| |
| data->dready_trig->ops = &stk8312_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, |
| stk8312_trigger_handler, |
| &stk8312_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 0; |
| |
| 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: |
| stk8312_set_mode(data, STK8312_MODE_STANDBY); |
| return ret; |
| } |
| |
| static int stk8312_remove(struct i2c_client *client) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| struct stk8312_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); |
| |
| stk8312_set_mode(data, STK8312_MODE_STANDBY); |
| |
| return 0; |
| } |
| |
| static int stk8312_suspend(struct device *dev) |
| { |
| struct stk8312_data *data; |
| |
| data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); |
| |
| return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); |
| } |
| |
| static int stk8312_resume(struct device *dev) |
| { |
| struct stk8312_data *data; |
| |
| data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); |
| |
| return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); |
| } |
| |
| static DEFINE_SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, |
| stk8312_resume); |
| |
| static const struct i2c_device_id stk8312_i2c_id[] = { |
| /* Deprecated in favour of lowercase form */ |
| { "STK8312", 0 }, |
| { "stk8312", 0 }, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id); |
| |
| static struct i2c_driver stk8312_driver = { |
| .driver = { |
| .name = STK8312_DRIVER_NAME, |
| .pm = pm_sleep_ptr(&stk8312_pm_ops), |
| }, |
| .probe = stk8312_probe, |
| .remove = stk8312_remove, |
| .id_table = stk8312_i2c_id, |
| }; |
| |
| module_i2c_driver(stk8312_driver); |
| |
| MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); |
| MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); |
| MODULE_LICENSE("GPL v2"); |