1 files changed, 154 insertions, 0 deletions

diff --git a/drivers/staging/iio/accel/adis16204_ring.c b/drivers/staging/iio/accel/adis16204_ring.c
new file mode 100644
index 00000000000..852df06684d
--- /dev/null
+++ b/drivers/staging/iio/accel/adis16204_ring.c
@@ -0,0 +1,154 @@
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "../ring_sw.h"
+#include "accel.h"
+#include "../trigger.h"
+#include "adis16204.h"
+
+/**
+ * adis16204_read_ring_data() read data registers which will be placed into ring
+ * @dev: device associated with child of actual device (iio_dev or iio_trig)
+ * @rx: somewhere to pass back the value read
+ **/
+static int adis16204_read_ring_data(struct device *dev, u8 *rx)
+{
+        struct spi_message msg;
+        struct iio_dev *indio_dev = dev_get_drvdata(dev);
+        struct adis16204_state *st = iio_priv(indio_dev);
+        struct spi_transfer xfers[ADIS16204_OUTPUTS + 1];
+        int ret;
+        int i;
+
+        mutex_lock(&st->buf_lock);
+
+        spi_message_init(&msg);
+
+        memset(xfers, 0, sizeof(xfers));
+        for (i = 0; i <= ADIS16204_OUTPUTS; i++) {
+                xfers[i].bits_per_word = 8;
+                xfers[i].cs_change = 1;
+                xfers[i].len = 2;
+                xfers[i].delay_usecs = 20;
+                xfers[i].tx_buf = st->tx + 2 * i;
+                st->tx[2 * i]
+                        = ADIS16204_READ_REG(ADIS16204_SUPPLY_OUT + 2 * i);
+                st->tx[2 * i + 1] = 0;
+                if (i >= 1)
+                        xfers[i].rx_buf = rx + 2 * (i - 1);
+                spi_message_add_tail(&xfers[i], &msg);
+        }
+
+        ret = spi_sync(st->us, &msg);
+        if (ret)
+                dev_err(&st->us->dev, "problem when burst reading");
+
+        mutex_unlock(&st->buf_lock);
+
+        return ret;
+}
+
+/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
+ * specific to be rolled into the core.
+ */
+static irqreturn_t adis16204_trigger_handler(int irq, void *p)
+{
+        struct iio_poll_func *pf = p;
+        struct iio_dev *indio_dev = pf->private_data;
+        struct adis16204_state *st = iio_priv(indio_dev);
+        struct iio_ring_buffer *ring = indio_dev->ring;
+        int i = 0;
+        s16 *data;
+        size_t datasize = ring->access->get_bytes_per_datum(ring);
+
+        data = kmalloc(datasize, GFP_KERNEL);
+        if (data == NULL) {
+                dev_err(&st->us->dev, "memory alloc failed in ring bh");
+                return -ENOMEM;
+        }
+
+        if (ring->scan_count)
+                if (adis16204_read_ring_data(&indio_dev->dev, st->rx) >= 0)
+                        for (; i < ring->scan_count; i++)
+                                data[i] = be16_to_cpup(
+                                        (__be16 *)&(st->rx[i*2]));
+
+        /* Guaranteed to be aligned with 8 byte boundary */
+        if (ring->scan_timestamp)
+                *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
+
+        ring->access->store_to(ring, (u8 *)data, pf->timestamp);
+
+        iio_trigger_notify_done(indio_dev->trig);
+        kfree(data);
+
+        return IRQ_HANDLED;
+}
+
+void adis16204_unconfigure_ring(struct iio_dev *indio_dev)
+{
+        iio_dealloc_pollfunc(indio_dev->pollfunc);
+        iio_sw_rb_free(indio_dev->ring);
+}
+
+static const struct iio_ring_setup_ops adis16204_ring_setup_ops = {
+        .preenable = &iio_sw_ring_preenable,
+        .postenable = &iio_triggered_ring_postenable,
+        .predisable = &iio_triggered_ring_predisable,
+};
+
+int adis16204_configure_ring(struct iio_dev *indio_dev)
+{
+        int ret = 0;
+        struct iio_ring_buffer *ring;
+
+        ring = iio_sw_rb_allocate(indio_dev);
+        if (!ring) {
+                ret = -ENOMEM;
+                return ret;
+        }
+        indio_dev->ring = ring;
+        /* Effectively select the ring buffer implementation */
+        ring->access = &ring_sw_access_funcs;
+        ring->bpe = 2;
+        ring->scan_timestamp = true;
+        ring->setup_ops = &adis16204_ring_setup_ops;
+        ring->owner = THIS_MODULE;
+
+        /* Set default scan mode */
+        iio_scan_mask_set(ring, ADIS16204_SCAN_SUPPLY);
+        iio_scan_mask_set(ring, ADIS16204_SCAN_ACC_X);
+        iio_scan_mask_set(ring, ADIS16204_SCAN_ACC_Y);
+        iio_scan_mask_set(ring, ADIS16204_SCAN_AUX_ADC);
+        iio_scan_mask_set(ring, ADIS16204_SCAN_TEMP);
+
+        indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
+                                                 &adis16204_trigger_handler,
+                                                 IRQF_ONESHOT,
+                                                 indio_dev,
+                                                 "%s_consumer%d",
+                                                 indio_dev->name,
+                                                 indio_dev->id);
+        if (indio_dev->pollfunc == NULL) {
+                ret = -ENOMEM;
+                goto error_iio_sw_rb_free;
+        }
+
+        indio_dev->modes |= INDIO_RING_TRIGGERED;
+        return 0;
+
+error_iio_sw_rb_free:
+        iio_sw_rb_free(indio_dev->ring);
+        return ret;
+}