/** * BMA220 Digital triaxial acceleration sensor driver * * Copyright (c) 2016, 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. */ #include <linux/acpi.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/iio/buffer.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/spi/spi.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #define BMA220_REG_ID 0x00 #define BMA220_REG_ACCEL_X 0x02 #define BMA220_REG_ACCEL_Y 0x03 #define BMA220_REG_ACCEL_Z 0x04 #define BMA220_REG_RANGE 0x11 #define BMA220_REG_SUSPEND 0x18 #define BMA220_CHIP_ID 0xDD #define BMA220_READ_MASK 0x80 #define BMA220_RANGE_MASK 0x03 #define BMA220_DATA_SHIFT 2 #define BMA220_SUSPEND_SLEEP 0xFF #define BMA220_SUSPEND_WAKE 0x00 #define BMA220_DEVICE_NAME "bma220" #define BMA220_SCALE_AVAILABLE "0.623 1.248 2.491 4.983" #define BMA220_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), \ .scan_index = index, \ .scan_type = { \ .sign = 's', \ .realbits = 6, \ .storagebits = 8, \ .shift = BMA220_DATA_SHIFT, \ .endianness = IIO_CPU, \ }, \ } enum bma220_axis { AXIS_X, AXIS_Y, AXIS_Z, }; static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE); static struct attribute *bma220_attributes[] = { &iio_const_attr_in_accel_scale_available.dev_attr.attr, NULL, }; static const struct attribute_group bma220_attribute_group = { .attrs = bma220_attributes, }; static const int bma220_scale_table[][4] = { {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000} }; struct bma220_data { struct spi_device *spi_device; struct mutex lock; s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */ u8 tx_buf[2] ____cacheline_aligned; }; static const struct iio_chan_spec bma220_channels[] = { BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X), BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y), BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z), IIO_CHAN_SOFT_TIMESTAMP(3), }; static inline int bma220_read_reg(struct spi_device *spi, u8 reg) { return spi_w8r8(spi, reg | BMA220_READ_MASK); } static const unsigned long bma220_accel_scan_masks[] = { BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z), 0 }; static irqreturn_t bma220_trigger_handler(int irq, void *p) { int ret; struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct bma220_data *data = iio_priv(indio_dev); struct spi_device *spi = data->spi_device; mutex_lock(&data->lock); data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK; ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer, ARRAY_SIZE(bma220_channels) - 1); if (ret < 0) goto err; iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, pf->timestamp); err: mutex_unlock(&data->lock); iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int bma220_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; u8 range_idx; struct bma220_data *data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: ret = bma220_read_reg(data->spi_device, chan->address); if (ret < 0) return -EINVAL; *val = sign_extend32(ret >> BMA220_DATA_SHIFT, 5); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE); if (ret < 0) return ret; range_idx = ret & BMA220_RANGE_MASK; *val = bma220_scale_table[range_idx][0]; *val2 = bma220_scale_table[range_idx][1]; return IIO_VAL_INT_PLUS_MICRO; } return -EINVAL; } static int bma220_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { int i; int ret; int index = -1; struct bma220_data *data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_SCALE: for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++) if (val == bma220_scale_table[i][0] && val2 == bma220_scale_table[i][1]) { index = i; break; } if (index < 0) return -EINVAL; mutex_lock(&data->lock); data->tx_buf[0] = BMA220_REG_RANGE; data->tx_buf[1] = index; ret = spi_write(data->spi_device, data->tx_buf, sizeof(data->tx_buf)); if (ret < 0) dev_err(&data->spi_device->dev, "failed to set measurement range\n"); mutex_unlock(&data->lock); return 0; } return -EINVAL; } static const struct iio_info bma220_info = { .driver_module = THIS_MODULE, .read_raw = bma220_read_raw, .write_raw = bma220_write_raw, .attrs = &bma220_attribute_group, }; static int bma220_init(struct spi_device *spi) { int ret; ret = bma220_read_reg(spi, BMA220_REG_ID); if (ret != BMA220_CHIP_ID) return -ENODEV; /* Make sure the chip is powered on */ ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); if (ret < 0) return ret; else if (ret == BMA220_SUSPEND_WAKE) return bma220_read_reg(spi, BMA220_REG_SUSPEND); return 0; } static int bma220_deinit(struct spi_device *spi) { int ret; /* Make sure the chip is powered off */ ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); if (ret < 0) return ret; else if (ret == BMA220_SUSPEND_SLEEP) return bma220_read_reg(spi, BMA220_REG_SUSPEND); return 0; } static int bma220_probe(struct spi_device *spi) { int ret; struct iio_dev *indio_dev; struct bma220_data *data; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data)); if (!indio_dev) { dev_err(&spi->dev, "iio allocation failed!\n"); return -ENOMEM; } data = iio_priv(indio_dev); data->spi_device = spi; spi_set_drvdata(spi, indio_dev); mutex_init(&data->lock); indio_dev->dev.parent = &spi->dev; indio_dev->info = &bma220_info; indio_dev->name = BMA220_DEVICE_NAME; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = bma220_channels; indio_dev->num_channels = ARRAY_SIZE(bma220_channels); indio_dev->available_scan_masks = bma220_accel_scan_masks; ret = bma220_init(data->spi_device); if (ret < 0) return ret; ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time, bma220_trigger_handler, NULL); if (ret < 0) { dev_err(&spi->dev, "iio triggered buffer setup failed\n"); goto err_suspend; } ret = iio_device_register(indio_dev); if (ret < 0) { dev_err(&spi->dev, "iio_device_register failed\n"); iio_triggered_buffer_cleanup(indio_dev); goto err_suspend; } return 0; err_suspend: return bma220_deinit(spi); } static int bma220_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); return bma220_deinit(spi); } #ifdef CONFIG_PM_SLEEP static int bma220_suspend(struct device *dev) { struct bma220_data *data = iio_priv(spi_get_drvdata(to_spi_device(dev))); /* The chip can be suspended/woken up by a simple register read. */ return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); } static int bma220_resume(struct device *dev) { struct bma220_data *data = iio_priv(spi_get_drvdata(to_spi_device(dev))); return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); } static SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume); #define BMA220_PM_OPS (&bma220_pm_ops) #else #define BMA220_PM_OPS NULL #endif static const struct spi_device_id bma220_spi_id[] = { {"bma220", 0}, {} }; static const struct acpi_device_id bma220_acpi_id[] = { {"BMA0220", 0}, {} }; MODULE_DEVICE_TABLE(spi, bma220_spi_id); static struct spi_driver bma220_driver = { .driver = { .name = "bma220_spi", .pm = BMA220_PM_OPS, .acpi_match_table = ACPI_PTR(bma220_acpi_id), }, .probe = bma220_probe, .remove = bma220_remove, .id_table = bma220_spi_id, }; module_spi_driver(bma220_driver); MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); MODULE_DESCRIPTION("BMA220 acceleration sensor driver"); MODULE_LICENSE("GPL v2");