/drivers/staging/iio/accel/adis16204_ring.c

  1#include <linux/interrupt.h>
  2#include <linux/irq.h>
  3#include <linux/gpio.h>
  4#include <linux/workqueue.h>
  5#include <linux/mutex.h>
  6#include <linux/device.h>
  7#include <linux/kernel.h>
  8#include <linux/spi/spi.h>
  9#include <linux/slab.h>
 10#include <linux/sysfs.h>
 11#include <linux/list.h>
 12
 13#include "../iio.h"
 14#include "../sysfs.h"
 15#include "../ring_sw.h"
 16#include "accel.h"
 17#include "../trigger.h"
 18#include "adis16204.h"
 19
 20/**
 21 * adis16204_read_ring_data() read data registers which will be placed into ring
 22 * @dev: device associated with child of actual device (iio_dev or iio_trig)
 23 * @rx: somewhere to pass back the value read
 24 **/
 25static int adis16204_read_ring_data(struct device *dev, u8 *rx)
 26{
 27	struct spi_message msg;
 28	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 29	struct adis16204_state *st = iio_priv(indio_dev);
 30	struct spi_transfer xfers[ADIS16204_OUTPUTS + 1];
 31	int ret;
 32	int i;
 33
 34	mutex_lock(&st->buf_lock);
 35
 36	spi_message_init(&msg);
 37
 38	memset(xfers, 0, sizeof(xfers));
 39	for (i = 0; i <= ADIS16204_OUTPUTS; i++) {
 40		xfers[i].bits_per_word = 8;
 41		xfers[i].cs_change = 1;
 42		xfers[i].len = 2;
 43		xfers[i].delay_usecs = 20;
 44		xfers[i].tx_buf = st->tx + 2 * i;
 45		st->tx[2 * i]
 46			= ADIS16204_READ_REG(ADIS16204_SUPPLY_OUT + 2 * i);
 47		st->tx[2 * i + 1] = 0;
 48		if (i >= 1)
 49			xfers[i].rx_buf = rx + 2 * (i - 1);
 50		spi_message_add_tail(&xfers[i], &msg);
 51	}
 52
 53	ret = spi_sync(st->us, &msg);
 54	if (ret)
 55		dev_err(&st->us->dev, "problem when burst reading");
 56
 57	mutex_unlock(&st->buf_lock);
 58
 59	return ret;
 60}
 61
 62/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 63 * specific to be rolled into the core.
 64 */
 65static irqreturn_t adis16204_trigger_handler(int irq, void *p)
 66{
 67	struct iio_poll_func *pf = p;
 68	struct iio_dev *indio_dev = pf->private_data;
 69	struct adis16204_state *st = iio_priv(indio_dev);
 70	struct iio_ring_buffer *ring = indio_dev->ring;
 71	int i = 0;
 72	s16 *data;
 73	size_t datasize = ring->access->get_bytes_per_datum(ring);
 74
 75	data = kmalloc(datasize, GFP_KERNEL);
 76	if (data == NULL) {
 77		dev_err(&st->us->dev, "memory alloc failed in ring bh");
 78		return -ENOMEM;
 79	}
 80
 81	if (ring->scan_count)
 82		if (adis16204_read_ring_data(&indio_dev->dev, st->rx) >= 0)
 83			for (; i < ring->scan_count; i++)
 84				data[i] = be16_to_cpup(
 85					(__be16 *)&(st->rx[i*2]));
 86
 87	/* Guaranteed to be aligned with 8 byte boundary */
 88	if (ring->scan_timestamp)
 89		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 90
 91	ring->access->store_to(ring, (u8 *)data, pf->timestamp);
 92
 93	iio_trigger_notify_done(indio_dev->trig);
 94	kfree(data);
 95
 96	return IRQ_HANDLED;
 97}
 98
 99void adis16204_unconfigure_ring(struct iio_dev *indio_dev)
100{
101	iio_dealloc_pollfunc(indio_dev->pollfunc);
102	iio_sw_rb_free(indio_dev->ring);
103}
104
105static const struct iio_ring_setup_ops adis16204_ring_setup_ops = {
106	.preenable = &iio_sw_ring_preenable,
107	.postenable = &iio_triggered_ring_postenable,
108	.predisable = &iio_triggered_ring_predisable,
109};
110
111int adis16204_configure_ring(struct iio_dev *indio_dev)
112{
113	int ret = 0;
114	struct iio_ring_buffer *ring;
115
116	ring = iio_sw_rb_allocate(indio_dev);
117	if (!ring) {
118		ret = -ENOMEM;
119		return ret;
120	}
121	indio_dev->ring = ring;
122	/* Effectively select the ring buffer implementation */
123	ring->access = &ring_sw_access_funcs;
124	ring->bpe = 2;
125	ring->scan_timestamp = true;
126	ring->setup_ops = &adis16204_ring_setup_ops;
127	ring->owner = THIS_MODULE;
128
129	/* Set default scan mode */
130	iio_scan_mask_set(ring, ADIS16204_SCAN_SUPPLY);
131	iio_scan_mask_set(ring, ADIS16204_SCAN_ACC_X);
132	iio_scan_mask_set(ring, ADIS16204_SCAN_ACC_Y);
133	iio_scan_mask_set(ring, ADIS16204_SCAN_AUX_ADC);
134	iio_scan_mask_set(ring, ADIS16204_SCAN_TEMP);
135
136	indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
137						 &adis16204_trigger_handler,
138						 IRQF_ONESHOT,
139						 indio_dev,
140						 "%s_consumer%d",
141						 indio_dev->name,
142						 indio_dev->id);
143	if (indio_dev->pollfunc == NULL) {
144		ret = -ENOMEM;
145		goto error_iio_sw_rb_free;
146	}
147
148	indio_dev->modes |= INDIO_RING_TRIGGERED;
149	return 0;
150
151error_iio_sw_rb_free:
152	iio_sw_rb_free(indio_dev->ring);
153	return ret;
154}