1 files changed, 254 insertions, 0 deletions
diff --git a/drivers/iio/adc/xilinx-xadc-events.c b/drivers/iio/adc/xilinx-xadc-events.c
new file mode 100644
index 000000000000..3e7f0d7a80c3
--- /dev/null
+++ b/drivers/iio/adc/xilinx-xadc-events.c
@@ -0,0 +1,254 @@
+/*
+ * Xilinx XADC driver
+ *
+ * Copyright 2013 Analog Devices Inc.
+ *  Author: Lars-Peter Clauen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+
+#include "xilinx-xadc.h"
+
+static const struct iio_chan_spec *xadc_event_to_channel(
+	struct iio_dev *indio_dev, unsigned int event)
+{
+	switch (event) {
+	case XADC_THRESHOLD_OT_MAX:
+	case XADC_THRESHOLD_TEMP_MAX:
+		return &indio_dev->channels[0];
+	case XADC_THRESHOLD_VCCINT_MAX:
+	case XADC_THRESHOLD_VCCAUX_MAX:
+		return &indio_dev->channels[event];
+	default:
+		return &indio_dev->channels[event-1];
+	}
+}
+
+static void xadc_handle_event(struct iio_dev *indio_dev, unsigned int event)
+{
+	const struct iio_chan_spec *chan;
+	unsigned int offset;
+
+	/* Temperature threshold error, we don't handle this yet */
+	if (event == 0)
+		return;
+
+	if (event < 4)
+		offset = event;
+	else
+		offset = event + 4;
+
+	chan = xadc_event_to_channel(indio_dev, event);
+
+	if (chan->type == IIO_TEMP) {
+		/*
+		 * The temperature channel only supports over-temperature
+		 * events.
+		 */
+		iio_push_event(indio_dev,
+			IIO_UNMOD_EVENT_CODE(chan->type, chan->channel,
+				IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING),
+			iio_get_time_ns());
+	} else {
+		/*
+		 * For other channels we don't know whether it is a upper or
+		 * lower threshold event. Userspace will have to check the
+		 * channel value if it wants to know.
+		 */
+		iio_push_event(indio_dev,
+			IIO_UNMOD_EVENT_CODE(chan->type, chan->channel,
+				IIO_EV_TYPE_THRESH, IIO_EV_DIR_EITHER),
+			iio_get_time_ns());
+	}
+}
+
+void xadc_handle_events(struct iio_dev *indio_dev, unsigned long events)
+{
+	unsigned int i;
+
+	for_each_set_bit(i, &events, 8)
+		xadc_handle_event(indio_dev, i);
+}
+
+static unsigned xadc_get_threshold_offset(const struct iio_chan_spec *chan,
+	enum iio_event_direction dir)
+{
+	unsigned int offset;
+
+	if (chan->type == IIO_TEMP) {
+		offset = XADC_THRESHOLD_OT_MAX;
+	} else {
+		if (chan->channel < 2)
+			offset = chan->channel + 1;
+		else
+			offset = chan->channel + 6;
+	}
+
+	if (dir == IIO_EV_DIR_FALLING)
+		offset += 4;
+
+	return offset;
+}
+
+static unsigned int xadc_get_alarm_mask(const struct iio_chan_spec *chan)
+{
+	if (chan->type == IIO_TEMP) {
+		return XADC_ALARM_OT_MASK;
+	} else {
+		switch (chan->channel) {
+		case 0:
+			return XADC_ALARM_VCCINT_MASK;
+		case 1:
+			return XADC_ALARM_VCCAUX_MASK;
+		case 2:
+			return XADC_ALARM_VCCBRAM_MASK;
+		case 3:
+			return XADC_ALARM_VCCPINT_MASK;
+		case 4:
+			return XADC_ALARM_VCCPAUX_MASK;
+		case 5:
+			return XADC_ALARM_VCCODDR_MASK;
+		default:
+			/* We will never get here */
+			return 0;
+		}
+	}
+}
+
+int xadc_read_event_config(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, enum iio_event_type type,
+	enum iio_event_direction dir)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+
+	return (bool)(xadc->alarm_mask & xadc_get_alarm_mask(chan));
+}
+
+int xadc_write_event_config(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, enum iio_event_type type,
+	enum iio_event_direction dir, int state)
+{
+	unsigned int alarm = xadc_get_alarm_mask(chan);
+	struct xadc *xadc = iio_priv(indio_dev);
+	uint16_t cfg, old_cfg;
+	int ret;
+
+	mutex_lock(&xadc->mutex);
+
+	if (state)
+		xadc->alarm_mask |= alarm;
+	else
+		xadc->alarm_mask &= ~alarm;
+
+	xadc->ops->update_alarm(xadc, xadc->alarm_mask);
+
+	ret = _xadc_read_adc_reg(xadc, XADC_REG_CONF1, &cfg);
+	if (ret)
+		goto err_out;
+
+	old_cfg = cfg;
+	cfg |= XADC_CONF1_ALARM_MASK;
+	cfg &= ~((xadc->alarm_mask & 0xf0) << 4); /* bram, pint, paux, ddr */
+	cfg &= ~((xadc->alarm_mask & 0x08) >> 3); /* ot */
+	cfg &= ~((xadc->alarm_mask & 0x07) << 1); /* temp, vccint, vccaux */
+	if (old_cfg != cfg)
+		ret = _xadc_write_adc_reg(xadc, XADC_REG_CONF1, cfg);
+
+err_out:
+	mutex_unlock(&xadc->mutex);
+
+	return ret;
+}
+
+/* Register value is msb aligned, the lower 4 bits are ignored */
+#define XADC_THRESHOLD_VALUE_SHIFT 4
+
+int xadc_read_event_value(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, enum iio_event_type type,
+	enum iio_event_direction dir, enum iio_event_info info,
+	int *val, int *val2)
+{
+	unsigned int offset = xadc_get_threshold_offset(chan, dir);
+	struct xadc *xadc = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		*val = xadc->threshold[offset];
+		break;
+	case IIO_EV_INFO_HYSTERESIS:
+		*val = xadc->temp_hysteresis;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*val >>= XADC_THRESHOLD_VALUE_SHIFT;
+
+	return IIO_VAL_INT;
+}
+
+int xadc_write_event_value(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, enum iio_event_type type,
+	enum iio_event_direction dir, enum iio_event_info info,
+	int val, int val2)
+{
+	unsigned int offset = xadc_get_threshold_offset(chan, dir);
+	struct xadc *xadc = iio_priv(indio_dev);
+	int ret = 0;
+
+	val <<= XADC_THRESHOLD_VALUE_SHIFT;
+
+	if (val < 0 || val > 0xffff)
+		return -EINVAL;
+
+	mutex_lock(&xadc->mutex);
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		xadc->threshold[offset] = val;
+		break;
+	case IIO_EV_INFO_HYSTERESIS:
+		xadc->temp_hysteresis = val;
+		break;
+	default:
+		mutex_unlock(&xadc->mutex);
+		return -EINVAL;
+	}
+
+	if (chan->type == IIO_TEMP) {
+		/*
+		 * According to the datasheet we need to set the lower 4 bits to
+		 * 0x3, otherwise 125 degree celsius will be used as the
+		 * threshold.
+		 */
+		val |= 0x3;
+
+		/*
+		 * Since we store the hysteresis as relative (to the threshold)
+		 * value, but the hardware expects an absolute value we need to
+		 * recalcualte this value whenever the hysteresis or the
+		 * threshold changes.
+		 */
+		if (xadc->threshold[offset] < xadc->temp_hysteresis)
+			xadc->threshold[offset + 4] = 0;
+		else
+			xadc->threshold[offset + 4] = xadc->threshold[offset] -
+					xadc->temp_hysteresis;
+		ret = _xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(offset + 4),
+			xadc->threshold[offset + 4]);
+		if (ret)
+			goto out_unlock;
+	}
+
+	if (info == IIO_EV_INFO_VALUE)
+		ret = _xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(offset), val);
+
+out_unlock:
+	mutex_unlock(&xadc->mutex);
+
+	return ret;
+}