#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/buffer.h>
-#include "../ring_hw.h"
+#include <linux/iio/kfifo_buf.h>
#define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02)
#define SCA3000_READ_REG(a) ((a) << 2)
struct mutex lock;
int bpse;
/* Can these share a cacheline ? */
- u8 rx[2] ____cacheline_aligned;
+ u8 rx[384] ____cacheline_aligned;
u8 tx[6] ____cacheline_aligned;
};
.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
};
+/*
+ * Note the hack in the number of bits to pretend we have 2 more than
+ * we do in the fifo.
+ */
#define SCA3000_CHAN(index, mod) \
{ \
.type = IIO_ACCEL, \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
- .realbits = 11, \
+ .realbits = 13, \
.storagebits = 16, \
- .shift = 5, \
+ .shift = 3, \
+ .endianness = IIO_BE, \
}, \
.event_spec = &sca3000_event, \
.num_event_specs = 1, \
.attrs = sca3000_attributes,
};
+static int sca3000_read_data(struct sca3000_state *st,
+ u8 reg_address_high,
+ u8 *rx,
+ int len)
+{
+ int ret;
+ struct spi_transfer xfer[2] = {
+ {
+ .len = 1,
+ .tx_buf = st->tx,
+ }, {
+ .len = len,
+ .rx_buf = rx,
+ }
+ };
+
+ st->tx[0] = SCA3000_READ_REG(reg_address_high);
+ ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
+ if (ret) {
+ dev_err(get_device(&st->us->dev), "problem reading register");
+ return ret;
+ }
+
+ return 0;
+}
+
/**
* sca3000_ring_int_process() ring specific interrupt handling.
*
* This is only split from the main interrupt handler so as to
* reduce the amount of code if the ring buffer is not enabled.
**/
-static void sca3000_ring_int_process(u8 val, struct iio_buffer *ring)
+static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
{
- if (val & (SCA3000_INT_STATUS_THREE_QUARTERS |
- SCA3000_INT_STATUS_HALF)) {
- ring->stufftoread = true;
- wake_up_interruptible(&ring->pollq);
+ struct sca3000_state *st = iio_priv(indio_dev);
+ int ret, i, num_available;
+
+ mutex_lock(&st->lock);
+ if (val & SCA3000_INT_STATUS_HALF) {
+ ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_BUF_COUNT,
+ 1);
+ if (ret)
+ goto error_ret;
+ num_available = st->rx[0];
+ /*
+ * num_available is the total number of samples available
+ * i.e. number of time points * number of channels.
+ */
+ ret = sca3000_read_data(st, SCA3000_REG_ADDR_RING_OUT, st->rx,
+ num_available * 2);
+ if (ret)
+ goto error_ret;
+ for (i = 0; i < num_available / 3; i++) {
+ /*
+ * Dirty hack to cover for 11 bit in fifo, 13 bit
+ * direct reading.
+ *
+ * In theory the bottom two bits are undefined.
+ * In reality they appear to always be 0.
+ */
+ iio_push_to_buffers(indio_dev, st->rx + i * 3 * 2);
+ }
}
+error_ret:
+ mutex_unlock(&st->lock);
}
/**
if (ret)
goto done;
- sca3000_ring_int_process(val, indio_dev->buffer);
+ sca3000_ring_int_process(val, indio_dev);
if (val & SCA3000_INT_STATUS_FREE_FALL)
iio_push_event(indio_dev,
.name = "events",
};
-static int sca3000_read_data(struct sca3000_state *st,
- u8 reg_address_high,
- u8 **rx_p,
- int len)
-{
- int ret;
- struct spi_transfer xfer[2] = {
- {
- .len = 1,
- .tx_buf = st->tx,
- }, {
- .len = len,
- }
- };
- *rx_p = kmalloc(len, GFP_KERNEL);
- if (!*rx_p) {
- ret = -ENOMEM;
- goto error_ret;
- }
- xfer[1].rx_buf = *rx_p;
- st->tx[0] = SCA3000_READ_REG(reg_address_high);
- ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));
- if (ret) {
- dev_err(get_device(&st->us->dev), "problem reading register");
- goto error_free_rx;
- }
-
- return 0;
-error_free_rx:
- kfree(*rx_p);
-error_ret:
- return ret;
-}
-
-/**
- * sca3000_read_first_n_hw_rb() - main ring access, pulls data from ring
- * @r: the ring
- * @count: number of samples to try and pull
- * @data: output the actual samples pulled from the hw ring
- *
- * Currently does not provide timestamps. As the hardware doesn't add them they
- * can only be inferred approximately from ring buffer events such as 50% full
- * and knowledge of when buffer was last emptied. This is left to userspace.
- **/
-static int sca3000_read_first_n_hw_rb(struct iio_buffer *r,
- size_t count, char __user *buf)
-{
- struct iio_hw_buffer *hw_ring = iio_to_hw_buf(r);
- struct iio_dev *indio_dev = hw_ring->private;
- struct sca3000_state *st = iio_priv(indio_dev);
- u8 *rx;
- int ret, i, num_available, num_read = 0;
- int bytes_per_sample = 1;
-
- if (st->bpse == 11)
- bytes_per_sample = 2;
-
- mutex_lock(&st->lock);
- if (count % bytes_per_sample) {
- ret = -EINVAL;
- goto error_ret;
- }
-
- ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_BUF_COUNT, 1);
- if (ret)
- goto error_ret;
- num_available = st->rx[0];
- /*
- * num_available is the total number of samples available
- * i.e. number of time points * number of channels.
- */
- if (count > num_available * bytes_per_sample)
- num_read = num_available * bytes_per_sample;
- else
- num_read = count;
-
- ret = sca3000_read_data(st,
- SCA3000_REG_ADDR_RING_OUT,
- &rx, num_read);
- if (ret)
- goto error_ret;
-
- for (i = 0; i < num_read / sizeof(u16); i++)
- *(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i);
-
- if (copy_to_user(buf, rx, num_read))
- ret = -EFAULT;
- kfree(rx);
- r->stufftoread = 0;
-error_ret:
- mutex_unlock(&st->lock);
-
- return ret ? ret : num_read;
-}
-
-static size_t sca3000_ring_buf_data_available(struct iio_buffer *r)
-{
- return r->stufftoread ? r->watermark : 0;
-}
-
-static ssize_t sca3000_show_buffer_scale(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct sca3000_state *st = iio_priv(indio_dev);
-
- return sprintf(buf, "0.%06d\n", 4 * st->info->scale);
-}
-
-static IIO_DEVICE_ATTR(in_accel_scale,
- S_IRUGO,
- sca3000_show_buffer_scale,
- NULL,
- 0);
-
-/*
- * Ring buffer attributes
- * This device is a bit unusual in that the sampling frequency and bpse
- * only apply to the ring buffer. At all times full rate and accuracy
- * is available via direct reading from registers.
- */
-static const struct attribute *sca3000_ring_attributes[] = {
- &iio_dev_attr_in_accel_scale.dev_attr.attr,
- NULL,
-};
-
-static struct iio_buffer *sca3000_rb_allocate(struct iio_dev *indio_dev)
-{
- struct iio_buffer *buf;
- struct iio_hw_buffer *ring;
-
- ring = kzalloc(sizeof(*ring), GFP_KERNEL);
- if (!ring)
- return NULL;
-
- ring->private = indio_dev;
- buf = &ring->buf;
- buf->stufftoread = 0;
- buf->length = 64;
- buf->attrs = sca3000_ring_attributes;
- iio_buffer_init(buf);
-
- return buf;
-}
-
-static void sca3000_ring_release(struct iio_buffer *r)
-{
- kfree(iio_to_hw_buf(r));
-}
-
-static const struct iio_buffer_access_funcs sca3000_ring_access_funcs = {
- .read_first_n = &sca3000_read_first_n_hw_rb,
- .data_available = sca3000_ring_buf_data_available,
- .release = sca3000_ring_release,
-
- .modes = INDIO_BUFFER_HARDWARE,
-};
-
static int sca3000_configure_ring(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer;
- buffer = sca3000_rb_allocate(indio_dev);
+ buffer = iio_kfifo_allocate();
if (!buffer)
return -ENOMEM;
- indio_dev->modes |= INDIO_BUFFER_HARDWARE;
- buffer->access = &sca3000_ring_access_funcs;
iio_device_attach_buffer(indio_dev, buffer);
+ indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
return 0;
}
static void sca3000_unconfigure_ring(struct iio_dev *indio_dev)
{
- iio_buffer_put(indio_dev->buffer);
+ iio_kfifo_free(indio_dev->buffer);
}
static inline
int ret;
struct sca3000_state *st = iio_priv(indio_dev);
- /*
- * Set stuff to read to indicate no data present.
- * Need for cases where the interrupt had fired at the
- * end of a cycle, but the data was never read.
- */
- indio_dev->buffer->stufftoread = 0;
- /*
- * Needed to ensure the core will actually read data
- * from the device rather than assuming no channels
- * are enabled.
- */
- indio_dev->buffer->bytes_per_datum = 6;
-
mutex_lock(&st->lock);
/* Enable the 50% full interrupt */
projects / users / hch / dma-mapping.git / commitdiff