Skip to content

Commit

Permalink
iio: accel: Add triggered buffer support for BMA220
Browse files Browse the repository at this point in the history
Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
  • Loading branch information
Tiberiu Breana authored and Jonathan Cameron committed May 21, 2016
1 parent ba35f11 commit 194dc4c
Showing 1 changed file with 63 additions and 2 deletions.
65 changes: 63 additions & 2 deletions drivers/iio/accel/bma220_spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -11,9 +11,12 @@
#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
Expand All @@ -39,8 +42,22 @@
.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[] = {
Expand All @@ -59,20 +76,51 @@ static const int bma220_scale_table[][4] = {
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)
Expand Down Expand Up @@ -199,25 +247,38 @@ static int bma220_probe(struct spi_device *spi)
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, NULL,
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");
return bma220_deinit(spi);
iio_triggered_buffer_cleanup(indio_dev);
goto err_suspend;
}

return ret;
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);
}
Expand Down

0 comments on commit 194dc4c

Please sign in to comment.