From b9618c0cacd7cf56cc3d073c1e9e9a8a3a12864e Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Tue, 22 Feb 2011 21:46:18 +0100 Subject: staging: IIO: ADC: New driver for AD7606/AD7606-6/AD7606-4 This patch adds support for the: AD7606/AD7606-6/AD7606-4 8/6/4-Channel Data Acquisition system (DAS) with 16-Bit, Bipolar, Simultaneous Sampling ADC. Changes since V1: IIO: ADC: New driver for AD7606/AD7606-6/AD7606-4: Apply review feedback Rename sysfs node oversampling to oversampling_ratio. Kconfig: Add GPIOLIB dependency. Use range in mV to better match HWMON. Rename ad7606_check_oversampling. Fix various comments and style. Reorder is_visible cases. Use new gpio_request_one/array and friends. Drop check for SPI max_speed_hz. Changes since V2: IIO: ADC: New driver for AD7606/AD7606-6/AD7606-4: Apply review feedback Documentation: specify unit Avoid raise condition in ad7606_scan_direct() Check return value of bus ops read_block() Changes since V3: IIO: ADC: New driver for AD7606/AD7606-6/AD7606-4: Add missing include file Add linux/sched.h Changes since V4: IIO: ADC: New driver for AD7606/AD7606-6/AD7606-4: Fix kconfig declaration consistently use tristate to avoid configuration mismatches Signed-off-by: Michael Hennerich Acked-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/adc/ad7606_ring.c | 266 ++++++++++++++++++++++++++++++++++ 1 file changed, 266 insertions(+) create mode 100644 drivers/staging/iio/adc/ad7606_ring.c (limited to 'drivers/staging/iio/adc/ad7606_ring.c') diff --git a/drivers/staging/iio/adc/ad7606_ring.c b/drivers/staging/iio/adc/ad7606_ring.c new file mode 100644 index 000000000000..9889680232d8 --- /dev/null +++ b/drivers/staging/iio/adc/ad7606_ring.c @@ -0,0 +1,266 @@ +/* + * Copyright 2011 Analog Devices Inc. + * + * Licensed under the GPL-2. + * + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "../iio.h" +#include "../ring_generic.h" +#include "../ring_sw.h" +#include "../trigger.h" +#include "../sysfs.h" + +#include "ad7606.h" + +static IIO_SCAN_EL_C(in0, 0, 0, NULL); +static IIO_SCAN_EL_C(in1, 1, 0, NULL); +static IIO_SCAN_EL_C(in2, 2, 0, NULL); +static IIO_SCAN_EL_C(in3, 3, 0, NULL); +static IIO_SCAN_EL_C(in4, 4, 0, NULL); +static IIO_SCAN_EL_C(in5, 5, 0, NULL); +static IIO_SCAN_EL_C(in6, 6, 0, NULL); +static IIO_SCAN_EL_C(in7, 7, 0, NULL); + +static ssize_t ad7606_show_type(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_ring_buffer *ring = dev_get_drvdata(dev); + struct iio_dev *indio_dev = ring->indio_dev; + struct ad7606_state *st = indio_dev->dev_data; + + return sprintf(buf, "%c%d/%d\n", st->chip_info->sign, + st->chip_info->bits, st->chip_info->bits); +} +static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7606_show_type, NULL, 0); + +static struct attribute *ad7606_scan_el_attrs[] = { + &iio_scan_el_in0.dev_attr.attr, + &iio_const_attr_in0_index.dev_attr.attr, + &iio_scan_el_in1.dev_attr.attr, + &iio_const_attr_in1_index.dev_attr.attr, + &iio_scan_el_in2.dev_attr.attr, + &iio_const_attr_in2_index.dev_attr.attr, + &iio_scan_el_in3.dev_attr.attr, + &iio_const_attr_in3_index.dev_attr.attr, + &iio_scan_el_in4.dev_attr.attr, + &iio_const_attr_in4_index.dev_attr.attr, + &iio_scan_el_in5.dev_attr.attr, + &iio_const_attr_in5_index.dev_attr.attr, + &iio_scan_el_in6.dev_attr.attr, + &iio_const_attr_in6_index.dev_attr.attr, + &iio_scan_el_in7.dev_attr.attr, + &iio_const_attr_in7_index.dev_attr.attr, + &iio_dev_attr_in_type.dev_attr.attr, + NULL, +}; + +static mode_t ad7606_scan_el_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct iio_ring_buffer *ring = dev_get_drvdata(dev); + struct iio_dev *indio_dev = ring->indio_dev; + struct ad7606_state *st = indio_dev->dev_data; + + mode_t mode = attr->mode; + + if (st->chip_info->num_channels <= 6 && + (attr == &iio_scan_el_in7.dev_attr.attr || + attr == &iio_const_attr_in7_index.dev_attr.attr || + attr == &iio_scan_el_in6.dev_attr.attr || + attr == &iio_const_attr_in6_index.dev_attr.attr)) + mode = 0; + else if (st->chip_info->num_channels <= 4 && + (attr == &iio_scan_el_in5.dev_attr.attr || + attr == &iio_const_attr_in5_index.dev_attr.attr || + attr == &iio_scan_el_in4.dev_attr.attr || + attr == &iio_const_attr_in4_index.dev_attr.attr)) + mode = 0; + + return mode; +} + +static struct attribute_group ad7606_scan_el_group = { + .name = "scan_elements", + .attrs = ad7606_scan_el_attrs, + .is_visible = ad7606_scan_el_attr_is_visible, +}; + +int ad7606_scan_from_ring(struct ad7606_state *st, unsigned ch) +{ + struct iio_ring_buffer *ring = st->indio_dev->ring; + int ret; + u16 *ring_data; + + ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL); + if (ring_data == NULL) { + ret = -ENOMEM; + goto error_ret; + } + ret = ring->access.read_last(ring, (u8 *) ring_data); + if (ret) + goto error_free_ring_data; + + ret = ring_data[ch]; + +error_free_ring_data: + kfree(ring_data); +error_ret: + return ret; +} + +/** + * ad7606_ring_preenable() setup the parameters of the ring before enabling + * + * The complex nature of the setting of the nuber of bytes per datum is due + * to this driver currently ensuring that the timestamp is stored at an 8 + * byte boundary. + **/ +static int ad7606_ring_preenable(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = indio_dev->dev_data; + struct iio_ring_buffer *ring = indio_dev->ring; + size_t d_size; + + d_size = st->chip_info->num_channels * + st->chip_info->bits / 8 + sizeof(s64); + + if (d_size % sizeof(s64)) + d_size += sizeof(s64) - (d_size % sizeof(s64)); + + if (ring->access.set_bytes_per_datum) + ring->access.set_bytes_per_datum(ring, d_size); + + st->d_size = d_size; + + return 0; +} + +/** + * ad7606_poll_func_th() th of trigger launched polling to ring buffer + * + **/ +static void ad7606_poll_func_th(struct iio_dev *indio_dev, s64 time) +{ + struct ad7606_state *st = indio_dev->dev_data; + gpio_set_value(st->pdata->gpio_convst, 1); + + return; +} +/** + * 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 = st->indio_dev; + struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring); + struct iio_ring_buffer *ring = indio_dev->ring; + s64 time_ns; + __u8 *buf; + int ret; + + /* Ensure only one copy of this function running at a time */ + if (atomic_inc_return(&st->protect_ring) > 1) + return; + + buf = kzalloc(st->d_size, GFP_KERNEL); + if (buf == NULL) + return; + + if (st->have_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; + } + + time_ns = iio_get_time_ns(); + memcpy(buf + st->d_size - sizeof(s64), &time_ns, sizeof(time_ns)); + + ring->access.store_to(&sw_ring->buf, buf, time_ns); +done: + gpio_set_value(st->pdata->gpio_convst, 0); + kfree(buf); + atomic_dec(&st->protect_ring); +} + +int ad7606_register_ring_funcs_and_init(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = indio_dev->dev_data; + int ret; + + indio_dev->ring = iio_sw_rb_allocate(indio_dev); + if (!indio_dev->ring) { + ret = -ENOMEM; + goto error_ret; + } + + /* Effectively select the ring buffer implementation */ + iio_ring_sw_register_funcs(&indio_dev->ring->access); + ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7606_poll_func_th); + if (ret) + goto error_deallocate_sw_rb; + + /* Ring buffer functions - here trigger setup related */ + + indio_dev->ring->preenable = &ad7606_ring_preenable; + indio_dev->ring->postenable = &iio_triggered_ring_postenable; + indio_dev->ring->predisable = &iio_triggered_ring_predisable; + indio_dev->ring->scan_el_attrs = &ad7606_scan_el_group; + + INIT_WORK(&st->poll_work, &ad7606_poll_bh_to_ring); + + /* Flag that polled ring buffering is possible */ + indio_dev->modes |= INDIO_RING_TRIGGERED; + return 0; +error_deallocate_sw_rb: + iio_sw_rb_free(indio_dev->ring); +error_ret: + return ret; +} + +void ad7606_ring_cleanup(struct iio_dev *indio_dev) +{ + if (indio_dev->trig) { + iio_put_trigger(indio_dev->trig); + iio_trigger_dettach_poll_func(indio_dev->trig, + indio_dev->pollfunc); + } + kfree(indio_dev->pollfunc); + iio_sw_rb_free(indio_dev->ring); +} -- cgit v1.2.3