diff options
Diffstat (limited to 'drivers/iio/accel/stk8312.c')
| -rw-r--r-- | drivers/iio/accel/stk8312.c | 676 |
1 files changed, 676 insertions, 0 deletions
diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c new file mode 100644 index 000000000..52c33addf --- /dev/null +++ b/drivers/iio/accel/stk8312.c @@ -0,0 +1,676 @@ +/** + * Sensortek STK8312 3-Axis Accelerometer + * + * Copyright (c) 2015, Intel Corporation. + * + * This file is subject to the terms and conditions of version 2 of + * the GNU General Public License. See the file COPYING in the main + * directory of this archive for more details. + * + * IIO driver for STK8312; 7-bit I2C address: 0x3D. + */ + +#include <linux/acpi.h> +#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, 7); + 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, + .postenable = iio_triggered_buffer_postenable, + .predisable = iio_triggered_buffer_predisable, + .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->dev.parent = &client->dev; + 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, + indio_dev->id); + if (!data->dready_trig) { + ret = -ENOMEM; + goto err_power_off; + } + + data->dready_trig->dev.parent = &client->dev; + 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); + + return stk8312_set_mode(data, STK8312_MODE_STANDBY); +} + +#ifdef CONFIG_PM_SLEEP +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 SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume); + +#define STK8312_PM_OPS (&stk8312_pm_ops) +#else +#define STK8312_PM_OPS NULL +#endif + +static const struct i2c_device_id stk8312_i2c_id[] = { + {"STK8312", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id); + +static const struct acpi_device_id stk8312_acpi_id[] = { + {"STK8312", 0}, + {} +}; + +MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id); + +static struct i2c_driver stk8312_driver = { + .driver = { + .name = STK8312_DRIVER_NAME, + .pm = STK8312_PM_OPS, + .acpi_match_table = ACPI_PTR(stk8312_acpi_id), + }, + .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"); |