diff options
Diffstat (limited to 'drivers/iio/accel/mxc4005.c')
| -rw-r--r-- | drivers/iio/accel/mxc4005.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c new file mode 100644 index 000000000..58099e40d --- /dev/null +++ b/drivers/iio/accel/mxc4005.c @@ -0,0 +1,536 @@ +/* + * 3-axis accelerometer driver for MXC4005XC Memsic sensor + * + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/acpi.h> +#include <linux/regmap.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/buffer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> + +#define MXC4005_DRV_NAME "mxc4005" +#define MXC4005_IRQ_NAME "mxc4005_event" +#define MXC4005_REGMAP_NAME "mxc4005_regmap" + +#define MXC4005_REG_XOUT_UPPER 0x03 +#define MXC4005_REG_XOUT_LOWER 0x04 +#define MXC4005_REG_YOUT_UPPER 0x05 +#define MXC4005_REG_YOUT_LOWER 0x06 +#define MXC4005_REG_ZOUT_UPPER 0x07 +#define MXC4005_REG_ZOUT_LOWER 0x08 + +#define MXC4005_REG_INT_MASK1 0x0B +#define MXC4005_REG_INT_MASK1_BIT_DRDYE 0x01 + +#define MXC4005_REG_INT_CLR1 0x01 +#define MXC4005_REG_INT_CLR1_BIT_DRDYC 0x01 + +#define MXC4005_REG_CONTROL 0x0D +#define MXC4005_REG_CONTROL_MASK_FSR GENMASK(6, 5) +#define MXC4005_CONTROL_FSR_SHIFT 5 + +#define MXC4005_REG_DEVICE_ID 0x0E + +enum mxc4005_axis { + AXIS_X, + AXIS_Y, + AXIS_Z, +}; + +enum mxc4005_range { + MXC4005_RANGE_2G, + MXC4005_RANGE_4G, + MXC4005_RANGE_8G, +}; + +struct mxc4005_data { + struct device *dev; + struct mutex mutex; + struct regmap *regmap; + struct iio_trigger *dready_trig; + __be16 buffer[8]; + bool trigger_enabled; +}; + +/* + * MXC4005 can operate in the following ranges: + * +/- 2G, 4G, 8G (the default +/-2G) + * + * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582 + * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164 + * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329 + */ +static const struct { + u8 range; + int scale; +} mxc4005_scale_table[] = { + {MXC4005_RANGE_2G, 9582}, + {MXC4005_RANGE_4G, 19164}, + {MXC4005_RANGE_8G, 38329}, +}; + + +static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329"); + +static struct attribute *mxc4005_attributes[] = { + &iio_const_attr_in_accel_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group mxc4005_attrs_group = { + .attrs = mxc4005_attributes, +}; + +static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MXC4005_REG_XOUT_UPPER: + case MXC4005_REG_XOUT_LOWER: + case MXC4005_REG_YOUT_UPPER: + case MXC4005_REG_YOUT_LOWER: + case MXC4005_REG_ZOUT_UPPER: + case MXC4005_REG_ZOUT_LOWER: + case MXC4005_REG_DEVICE_ID: + case MXC4005_REG_CONTROL: + return true; + default: + return false; + } +} + +static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MXC4005_REG_INT_CLR1: + case MXC4005_REG_INT_MASK1: + case MXC4005_REG_CONTROL: + return true; + default: + return false; + } +} + +static const struct regmap_config mxc4005_regmap_config = { + .name = MXC4005_REGMAP_NAME, + + .reg_bits = 8, + .val_bits = 8, + + .max_register = MXC4005_REG_DEVICE_ID, + + .readable_reg = mxc4005_is_readable_reg, + .writeable_reg = mxc4005_is_writeable_reg, +}; + +static int mxc4005_read_xyz(struct mxc4005_data *data) +{ + int ret; + + ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER, + (u8 *) data->buffer, sizeof(data->buffer)); + if (ret < 0) { + dev_err(data->dev, "failed to read axes\n"); + return ret; + } + + return 0; +} + +static int mxc4005_read_axis(struct mxc4005_data *data, + unsigned int addr) +{ + __be16 reg; + int ret; + + ret = regmap_bulk_read(data->regmap, addr, (u8 *) ®, sizeof(reg)); + if (ret < 0) { + dev_err(data->dev, "failed to read reg %02x\n", addr); + return ret; + } + + return be16_to_cpu(reg); +} + +static int mxc4005_read_scale(struct mxc4005_data *data) +{ + unsigned int reg; + int ret; + int i; + + ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, ®); + if (ret < 0) { + dev_err(data->dev, "failed to read reg_control\n"); + return ret; + } + + i = reg >> MXC4005_CONTROL_FSR_SHIFT; + + if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table)) + return -EINVAL; + + return mxc4005_scale_table[i].scale; +} + +static int mxc4005_set_scale(struct mxc4005_data *data, int val) +{ + unsigned int reg; + int i; + int ret; + + for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) { + if (mxc4005_scale_table[i].scale == val) { + reg = i << MXC4005_CONTROL_FSR_SHIFT; + ret = regmap_update_bits(data->regmap, + MXC4005_REG_CONTROL, + MXC4005_REG_CONTROL_MASK_FSR, + reg); + if (ret < 0) + dev_err(data->dev, + "failed to write reg_control\n"); + return ret; + } + } + + return -EINVAL; +} + +static int mxc4005_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mxc4005_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_ACCEL: + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + + ret = mxc4005_read_axis(data, chan->address); + if (ret < 0) + return ret; + *val = sign_extend32(ret >> chan->scan_type.shift, + chan->scan_type.realbits - 1); + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_SCALE: + ret = mxc4005_read_scale(data); + if (ret < 0) + return ret; + + *val = 0; + *val2 = ret; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static int mxc4005_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct mxc4005_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + if (val != 0) + return -EINVAL; + + return mxc4005_set_scale(data, val2); + default: + return -EINVAL; + } +} + +static const struct iio_info mxc4005_info = { + .read_raw = mxc4005_read_raw, + .write_raw = mxc4005_write_raw, + .attrs = &mxc4005_attrs_group, +}; + +static const unsigned long mxc4005_scan_masks[] = { + BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z), + 0 +}; + +#define MXC4005_CHANNEL(_axis, _addr) { \ + .type = IIO_ACCEL, \ + .modified = 1, \ + .channel2 = IIO_MOD_##_axis, \ + .address = _addr, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .scan_index = AXIS_##_axis, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 12, \ + .storagebits = 16, \ + .shift = 4, \ + .endianness = IIO_BE, \ + }, \ +} + +static const struct iio_chan_spec mxc4005_channels[] = { + MXC4005_CHANNEL(X, MXC4005_REG_XOUT_UPPER), + MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER), + MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +static irqreturn_t mxc4005_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = private; + struct iio_dev *indio_dev = pf->indio_dev; + struct mxc4005_data *data = iio_priv(indio_dev); + int ret; + + ret = mxc4005_read_xyz(data); + if (ret < 0) + goto err; + + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, + pf->timestamp); + +err: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int mxc4005_clr_intr(struct mxc4005_data *data) +{ + int ret; + + /* clear interrupt */ + ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1, + MXC4005_REG_INT_CLR1_BIT_DRDYC); + if (ret < 0) { + dev_err(data->dev, "failed to write to reg_int_clr1\n"); + return ret; + } + + return 0; +} + +static int mxc4005_set_trigger_state(struct iio_trigger *trig, + bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct mxc4005_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->mutex); + if (state) { + ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, + MXC4005_REG_INT_MASK1_BIT_DRDYE); + } else { + ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, + ~MXC4005_REG_INT_MASK1_BIT_DRDYE); + } + + if (ret < 0) { + mutex_unlock(&data->mutex); + dev_err(data->dev, "failed to update reg_int_mask1"); + return ret; + } + + data->trigger_enabled = state; + mutex_unlock(&data->mutex); + + return 0; +} + +static int mxc4005_trigger_try_reen(struct iio_trigger *trig) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct mxc4005_data *data = iio_priv(indio_dev); + + if (!data->dready_trig) + return 0; + + return mxc4005_clr_intr(data); +} + +static const struct iio_trigger_ops mxc4005_trigger_ops = { + .set_trigger_state = mxc4005_set_trigger_state, + .try_reenable = mxc4005_trigger_try_reen, +}; + +static int mxc4005_chip_init(struct mxc4005_data *data) +{ + int ret; + unsigned int reg; + + ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, ®); + if (ret < 0) { + dev_err(data->dev, "failed to read chip id\n"); + return ret; + } + + dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg); + + return 0; +} + +static int mxc4005_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct mxc4005_data *data; + struct iio_dev *indio_dev; + struct regmap *regmap; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config); + if (IS_ERR(regmap)) { + dev_err(&client->dev, "failed to initialize regmap\n"); + return PTR_ERR(regmap); + } + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->dev = &client->dev; + data->regmap = regmap; + + ret = mxc4005_chip_init(data); + if (ret < 0) { + dev_err(&client->dev, "failed to initialize chip\n"); + return ret; + } + + mutex_init(&data->mutex); + + indio_dev->dev.parent = &client->dev; + indio_dev->channels = mxc4005_channels; + indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels); + indio_dev->available_scan_masks = mxc4005_scan_masks; + indio_dev->name = MXC4005_DRV_NAME; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &mxc4005_info; + + ret = iio_triggered_buffer_setup(indio_dev, + iio_pollfunc_store_time, + mxc4005_trigger_handler, + NULL); + if (ret < 0) { + dev_err(&client->dev, + "failed to setup iio triggered buffer\n"); + return ret; + } + + if (client->irq > 0) { + data->dready_trig = devm_iio_trigger_alloc(&client->dev, + "%s-dev%d", + indio_dev->name, + indio_dev->id); + if (!data->dready_trig) + return -ENOMEM; + + ret = devm_request_threaded_irq(&client->dev, client->irq, + iio_trigger_generic_data_rdy_poll, + NULL, + IRQF_TRIGGER_FALLING | + IRQF_ONESHOT, + MXC4005_IRQ_NAME, + data->dready_trig); + if (ret) { + dev_err(&client->dev, + "failed to init threaded irq\n"); + goto err_buffer_cleanup; + } + + data->dready_trig->dev.parent = &client->dev; + data->dready_trig->ops = &mxc4005_trigger_ops; + iio_trigger_set_drvdata(data->dready_trig, indio_dev); + indio_dev->trig = data->dready_trig; + iio_trigger_get(indio_dev->trig); + ret = iio_trigger_register(data->dready_trig); + if (ret) { + dev_err(&client->dev, + "failed to register trigger\n"); + goto err_trigger_unregister; + } + } + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, + "unable to register iio device %d\n", ret); + goto err_buffer_cleanup; + } + + return 0; + +err_trigger_unregister: + iio_trigger_unregister(data->dready_trig); +err_buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); + + return ret; +} + +static int mxc4005_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct mxc4005_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 0; +} + +static const struct acpi_device_id mxc4005_acpi_match[] = { + {"MXC4005", 0}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match); + +static const struct i2c_device_id mxc4005_id[] = { + {"mxc4005", 0}, + { }, +}; +MODULE_DEVICE_TABLE(i2c, mxc4005_id); + +static struct i2c_driver mxc4005_driver = { + .driver = { + .name = MXC4005_DRV_NAME, + .acpi_match_table = ACPI_PTR(mxc4005_acpi_match), + }, + .probe = mxc4005_probe, + .remove = mxc4005_remove, + .id_table = mxc4005_id, +}; + +module_i2c_driver(mxc4005_driver); + +MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver"); |