diff options
Diffstat (limited to 'drivers/iio/adc/xilinx-xadc-events.c')
| -rw-r--r-- | drivers/iio/adc/xilinx-xadc-events.c | 246 |
1 files changed, 246 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 000000000..dc0670308 --- /dev/null +++ b/drivers/iio/adc/xilinx-xadc-events.c @@ -0,0 +1,246 @@ +/* + * 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; + + /* Temperature threshold error, we don't handle this yet */ + if (event == 0) + return; + + 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(indio_dev)); + } 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(indio_dev)); + } +} + +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 int 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; + 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; +} |