// 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 #include #include #include #include #include #include #include #include #include #include #include #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]; aligned_s64 timestamp; } 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 { iio_for_each_active_channel(indio_dev, bit) { 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) { 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 void 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); } 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" }, { "stk8312" }, {} }; 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 "); MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); MODULE_LICENSE("GPL v2");