Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / staging / iio / adc / ad7606_ring.c

diff --git a/kernel/drivers/staging/iio/adc/ad7606_ring.c b/kernel/drivers/staging/iio/adc/ad7606_ring.c
new file mode 100644 (file)
index 0000000..a6f8eb1
--- /dev/null
+++ b/kernel/drivers/staging/iio/adc/ad7606_ring.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2011-2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include "ad7606.h"
+
+/**
+ * ad7606_trigger_handler_th() th/bh of trigger launched polling to ring buffer
+ *
+ **/
+static irqreturn_t ad7606_trigger_handler_th_bh(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct ad7606_state *st = iio_priv(pf->indio_dev);
+
+       gpio_set_value(st->pdata->gpio_convst, 1);
+
+       return IRQ_HANDLED;
+}
+
+/**
+ * ad7606_poll_bh_to_ring() bh of trigger launched polling to ring buffer
+ * @work_s:    the work struct through which this was scheduled
+ *
+ * Currently there is no option in this driver to disable the saving of
+ * timestamps within the ring.
+ * I think the one copy of this at a time was to avoid problems if the
+ * trigger was set far too high and the reads then locked up the computer.
+ **/
+static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
+{
+       struct ad7606_state *st = container_of(work_s, struct ad7606_state,
+                                               poll_work);
+       struct iio_dev *indio_dev = iio_priv_to_dev(st);
+       __u8 *buf;
+       int ret;
+
+       buf = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
+       if (!buf)
+               return;
+
+       if (gpio_is_valid(st->pdata->gpio_frstdata)) {
+               ret = st->bops->read_block(st->dev, 1, buf);
+               if (ret)
+                       goto done;
+               if (!gpio_get_value(st->pdata->gpio_frstdata)) {
+                       /* This should never happen. However
+                        * some signal glitch caused by bad PCB desgin or
+                        * electrostatic discharge, could cause an extra read
+                        * or clock. This allows recovery.
+                        */
+                       ad7606_reset(st);
+                       goto done;
+               }
+               ret = st->bops->read_block(st->dev,
+                       st->chip_info->num_channels - 1, buf + 2);
+               if (ret)
+                       goto done;
+       } else {
+               ret = st->bops->read_block(st->dev,
+                       st->chip_info->num_channels, buf);
+               if (ret)
+                       goto done;
+       }
+
+       iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
+done:
+       gpio_set_value(st->pdata->gpio_convst, 0);
+       iio_trigger_notify_done(indio_dev->trig);
+       kfree(buf);
+}
+
+int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev)
+{
+       struct ad7606_state *st = iio_priv(indio_dev);
+
+       INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring);
+
+       return iio_triggered_buffer_setup(indio_dev,
+               &ad7606_trigger_handler_th_bh, &ad7606_trigger_handler_th_bh,
+               NULL);
+}
+
+void ad7606_ring_cleanup(struct iio_dev *indio_dev)
+{
+       iio_triggered_buffer_cleanup(indio_dev);
+}