diff options
Diffstat (limited to 'drivers/iio/accel/bma220_spi.c')
| -rw-r--r-- | drivers/iio/accel/bma220_spi.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/iio/accel/bma220_spi.c b/drivers/iio/accel/bma220_spi.c new file mode 100644 index 000000000..fcbd695e4 --- /dev/null +++ b/drivers/iio/accel/bma220_spi.c @@ -0,0 +1,331 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * BMA220 Digital triaxial acceleration sensor driver + * + * Copyright (c) 2016,2020 Intel Corporation. + */ + +#include <linux/bits.h> +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/spi/spi.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.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 BIT(7) +#define BMA220_RANGE_MASK GENMASK(1, 0) +#define BMA220_SUSPEND_SLEEP 0xFF +#define BMA220_SUSPEND_WAKE 0x00 + +#define BMA220_DEVICE_NAME "bma220" + +#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 = 2, \ + .endianness = IIO_CPU, \ + }, \ +} + +enum bma220_axis { + AXIS_X, + AXIS_Y, + AXIS_Z, +}; + +static const int bma220_scale_table[][2] = { + {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000}, +}; + +struct bma220_data { + struct spi_device *spi_device; + struct mutex lock; + struct { + s8 chans[3]; + /* Ensure timestamp is naturally aligned. */ + s64 timestamp __aligned(8); + } scan; + u8 tx_buf[2] __aligned(IIO_DMA_MINALIGN); +}; + +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->scan.chans, + ARRAY_SIZE(bma220_channels) - 1); + if (ret < 0) + goto err; + + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + 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 >> chan->scan_type.shift, + chan->scan_type.realbits - 1); + 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 int bma220_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SCALE: + *vals = (int *)bma220_scale_table; + *type = IIO_VAL_INT_PLUS_MICRO; + *length = ARRAY_SIZE(bma220_scale_table) * 2; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } +} + +static const struct iio_info bma220_info = { + .read_raw = bma220_read_raw, + .write_raw = bma220_write_raw, + .read_avail = bma220_read_avail, +}; + +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 == BMA220_SUSPEND_WAKE) + ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); + if (ret < 0) + return ret; + if (ret == BMA220_SUSPEND_WAKE) + return -EBUSY; + + return 0; +} + +static int bma220_power(struct spi_device *spi, bool up) +{ + int i, ret; + + /** + * The chip can be suspended/woken up by a simple register read. + * So, we need up to 2 register reads of the suspend register + * to make sure that the device is in the desired state. + */ + for (i = 0; i < 2; i++) { + ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); + if (ret < 0) + return ret; + + if (up && ret == BMA220_SUSPEND_SLEEP) + return 0; + + if (!up && ret == BMA220_SUSPEND_WAKE) + return 0; + } + + return -EBUSY; +} + +static void bma220_deinit(void *spi) +{ + bma220_power(spi, false); +} + +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; + mutex_init(&data->lock); + + 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) + return ret; + + ret = devm_add_action_or_reset(&spi->dev, bma220_deinit, spi); + if (ret) + return ret; + + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, + iio_pollfunc_store_time, + bma220_trigger_handler, NULL); + if (ret < 0) { + dev_err(&spi->dev, "iio triggered buffer setup failed\n"); + return ret; + } + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static int bma220_suspend(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + + return bma220_power(spi, false); +} + +static int bma220_resume(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + + return bma220_power(spi, true); +} +static DEFINE_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume); + +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 = pm_sleep_ptr(&bma220_pm_ops), + .acpi_match_table = bma220_acpi_id, + }, + .probe = bma220_probe, + .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"); |