/* * itg3200_core.c -- support InvenSense ITG3200 * Digital 3-Axis Gyroscope driver * * Copyright (c) 2011 Christian Strobel * Copyright (c) 2011 Manuel Stahl * Copyright (c) 2012 Thorsten Nowak * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * TODO: * - Support digital low pass filter * - Support power management */ #include #include #include #include #include #include #include #include #include #include #include #include #include int itg3200_write_reg_8(struct iio_dev *indio_dev, u8 reg_address, u8 val) { struct itg3200 *st = iio_priv(indio_dev); return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val); } int itg3200_read_reg_8(struct iio_dev *indio_dev, u8 reg_address, u8 *val) { struct itg3200 *st = iio_priv(indio_dev); int ret; ret = i2c_smbus_read_byte_data(st->i2c, reg_address); if (ret < 0) return ret; *val = ret; return 0; } static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address, int *val) { struct itg3200 *st = iio_priv(indio_dev); struct i2c_client *client = st->i2c; int ret; s16 out; struct i2c_msg msg[2] = { { .addr = client->addr, .flags = client->flags, .len = 1, .buf = (char *)&lower_reg_address, }, { .addr = client->addr, .flags = client->flags | I2C_M_RD, .len = 2, .buf = (char *)&out, }, }; lower_reg_address |= 0x80; ret = i2c_transfer(client->adapter, msg, 2); be16_to_cpus(&out); *val = out; return (ret == 2) ? 0 : ret; } static int itg3200_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long info) { int ret = 0; u8 reg; switch (info) { case IIO_CHAN_INFO_RAW: reg = (u8)chan->address; ret = itg3200_read_reg_s16(indio_dev, reg, val); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; if (chan->type == IIO_TEMP) *val2 = 1000000000/280; else *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */ return IIO_VAL_INT_PLUS_NANO; case IIO_CHAN_INFO_OFFSET: /* Only the temperature channel has an offset */ *val = 23000; return IIO_VAL_INT; default: return -EINVAL; } return ret; } static ssize_t itg3200_read_frequency(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); int ret, sps; u8 val; ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); if (ret) return ret; sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000; ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val); if (ret) return ret; sps /= val + 1; return sprintf(buf, "%d\n", sps); } static ssize_t itg3200_write_frequency(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); unsigned val; int ret; u8 t; ret = kstrtouint(buf, 10, &val); if (ret) return ret; mutex_lock(&indio_dev->mlock); ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t); if (ret) goto err_ret; if (val == 0) { ret = -EINVAL; goto err_ret; } t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1; ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t); err_ret: mutex_unlock(&indio_dev->mlock); return ret ? ret : len; } /* * Reset device and internal registers to the power-up-default settings * Use the gyro clock as reference, as suggested by the datasheet */ static int itg3200_reset(struct iio_dev *indio_dev) { struct itg3200 *st = iio_priv(indio_dev); int ret; dev_dbg(&st->i2c->dev, "reset device"); ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT, ITG3200_RESET); if (ret) { dev_err(&st->i2c->dev, "error resetting device"); goto error_ret; } /* Wait for PLL (1ms according to datasheet) */ udelay(1500); ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, ITG3200_IRQ_ACTIVE_HIGH | ITG3200_IRQ_PUSH_PULL | ITG3200_IRQ_LATCH_50US_PULSE | ITG3200_IRQ_LATCH_CLEAR_ANY); if (ret) dev_err(&st->i2c->dev, "error init device"); error_ret: return ret; } /* itg3200_enable_full_scale() - Disables the digital low pass filter */ static int itg3200_enable_full_scale(struct iio_dev *indio_dev) { u8 val; int ret; ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); if (ret) goto err_ret; val |= ITG3200_DLPF_FS_SEL_2000; return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val); err_ret: return ret; } static int itg3200_initial_setup(struct iio_dev *indio_dev) { struct itg3200 *st = iio_priv(indio_dev); int ret; u8 val; ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); if (ret) goto err_ret; if (((val >> 1) & 0x3f) != 0x34) { dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val); ret = -ENXIO; goto err_ret; } ret = itg3200_reset(indio_dev); if (ret) goto err_ret; ret = itg3200_enable_full_scale(indio_dev); err_ret: return ret; } #define ITG3200_ST \ { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE } #define ITG3200_GYRO_CHAN(_mod) { \ .type = IIO_ANGL_VEL, \ .modified = 1, \ .channel2 = IIO_MOD_ ## _mod, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \ .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \ .scan_type = ITG3200_ST, \ } static const struct iio_chan_spec itg3200_channels[] = { { .type = IIO_TEMP, .channel2 = IIO_NO_MOD, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), .address = ITG3200_REG_TEMP_OUT_H, .scan_index = ITG3200_SCAN_TEMP, .scan_type = ITG3200_ST, }, ITG3200_GYRO_CHAN(X), ITG3200_GYRO_CHAN(Y), ITG3200_GYRO_CHAN(Z), IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS), }; /* IIO device attributes */ static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency, itg3200_write_frequency); static struct attribute *itg3200_attributes[] = { &iio_dev_attr_sampling_frequency.dev_attr.attr, NULL }; static const struct attribute_group itg3200_attribute_group = { .attrs = itg3200_attributes, }; static const struct iio_info itg3200_info = { .attrs = &itg3200_attribute_group, .read_raw = &itg3200_read_raw, .driver_module = THIS_MODULE, }; static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 }; static int itg3200_probe(struct i2c_client *client, const struct i2c_device_id *id) { int ret; struct itg3200 *st; struct iio_dev *indio_dev; dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq); indio_dev = iio_device_alloc(sizeof(*st)); if (indio_dev == NULL) { ret = -ENOMEM; goto error_ret; } st = iio_priv(indio_dev); i2c_set_clientdata(client, indio_dev); st->i2c = client; indio_dev->dev.parent = &client->dev; indio_dev->name = client->dev.driver->name; indio_dev->channels = itg3200_channels; indio_dev->num_channels = ARRAY_SIZE(itg3200_channels); indio_dev->available_scan_masks = itg3200_available_scan_masks; indio_dev->info = &itg3200_info; indio_dev->modes = INDIO_DIRECT_MODE; ret = itg3200_buffer_configure(indio_dev); if (ret) goto error_free_dev; if (client->irq) { ret = itg3200_probe_trigger(indio_dev); if (ret) goto error_unconfigure_buffer; } ret = itg3200_initial_setup(indio_dev); if (ret) goto error_remove_trigger; ret = iio_device_register(indio_dev); if (ret) goto error_remove_trigger; return 0; error_remove_trigger: if (client->irq) itg3200_remove_trigger(indio_dev); error_unconfigure_buffer: itg3200_buffer_unconfigure(indio_dev); error_free_dev: iio_device_free(indio_dev); error_ret: return ret; } static int itg3200_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); iio_device_unregister(indio_dev); if (client->irq) itg3200_remove_trigger(indio_dev); itg3200_buffer_unconfigure(indio_dev); iio_device_free(indio_dev); return 0; } static const struct i2c_device_id itg3200_id[] = { { "itg3200", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, itg3200_id); static struct i2c_driver itg3200_driver = { .driver = { .owner = THIS_MODULE, .name = "itg3200", }, .id_table = itg3200_id, .probe = itg3200_probe, .remove = itg3200_remove, }; module_i2c_driver(itg3200_driver); MODULE_AUTHOR("Christian Strobel "); MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver"); MODULE_LICENSE("GPL v2");