diff options
Diffstat (limited to 'drivers/staging/iio/adc/ad7606_ring.c')
-rw-r--r-- | drivers/staging/iio/adc/ad7606_ring.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/staging/iio/adc/ad7606_ring.c b/drivers/staging/iio/adc/ad7606_ring.c new file mode 100644 index 000000000..a6f8eb112 --- /dev/null +++ b/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); +} |