[deliverable/linux.git] / drivers / staging / iio / adc / max1363_ring.c

/*
 * Copyright (C) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * max1363_ring.c
 */

#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/workqueue.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/sysfs.h>
#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/bitops.h>

#include "../iio.h"
#include "../ring_generic.h"
#include "../ring_sw.h"
#include "../trigger.h"
#include "../sysfs.h"

#include "max1363.h"

/* Todo: test this */
int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
{
	struct iio_ring_buffer *ring = st->indio_dev->ring;
	int count = 0, ret;
	u8 *ring_data;
	if (!(st->current_mode->modemask & mask)) {
		ret = -EBUSY;
		goto error_ret;
	}

	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, ring_data);
	if (ret)
		goto error_free_ring_data;
	/* Need a count of channels prior to this one */
	mask >>= 1;
	while (mask) {
		if (mask & st->current_mode->modemask)
			count++;
		mask >>= 1;
	}
	if (st->chip_info->bits != 8)
		ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8)
			+ (int)(ring_data[count*2 + 1]);
	else
		ret = ring_data[count];

error_free_ring_data:
	kfree(ring_data);
error_ret:
	return ret;
}

/**
 * max1363_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 max1363_ring_preenable(struct iio_dev *indio_dev)
{
	struct max1363_state *st = indio_dev->dev_data;
	struct iio_ring_buffer *ring = indio_dev->ring;
	size_t d_size;
	unsigned long numvals;

	/*
	 * Need to figure out the current mode based upon the requested
	 * scan mask in iio_dev
	 */
	st->current_mode = max1363_match_mode(ring->scan_mask,
					st->chip_info);
	if (!st->current_mode)
		return -EINVAL;

	max1363_set_scan_mode(st);

	numvals = hweight_long(st->current_mode->modemask);
	if (ring->access.set_bytes_per_datum) {
		if (st->chip_info->bits != 8)
			d_size = numvals*2 + sizeof(s64);
		else
			d_size = numvals + sizeof(s64);
		if (d_size % 8)
			d_size += 8 - (d_size % 8);
		ring->access.set_bytes_per_datum(ring, d_size);
	}

	return 0;
}


/**
 * max1363_poll_func_th() - th of trigger launched polling to ring buffer
 *
 * As sampling only occurs on i2c comms occurring, leave timestamping until
 * then.  Some triggers will generate their own time stamp.  Currently
 * there is no way of notifying them when no one cares.
 **/
static void max1363_poll_func_th(struct iio_dev *indio_dev, s64 time)
{
	struct max1363_state *st = indio_dev->dev_data;

	schedule_work(&st->poll_work);

	return;
}
/**
 * max1363_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 max1363_poll_bh_to_ring(struct work_struct *work_s)
{
	struct max1363_state *st = container_of(work_s, struct max1363_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);
	s64 time_ns;
	__u8 *rxbuf;
	int b_sent;
	size_t d_size;
	unsigned long numvals = hweight_long(st->current_mode->modemask);

	/* Ensure the timestamp is 8 byte aligned */
	if (st->chip_info->bits != 8)
		d_size = numvals*2 + sizeof(s64);
	else
		d_size = numvals + sizeof(s64);
	if (d_size % sizeof(s64))
		d_size += sizeof(s64) - (d_size % sizeof(s64));

	/* Ensure only one copy of this function running at a time */
	if (atomic_inc_return(&st->protect_ring) > 1)
		return;

	/* Monitor mode prevents reading. Whilst not currently implemented
	 * might as well have this test in here in the meantime as it does
	 * no harm.
	 */
	if (numvals == 0)
		return;

	rxbuf = kmalloc(d_size,	GFP_KERNEL);
	if (rxbuf == NULL)
		return;
	if (st->chip_info->bits != 8)
		b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
	else
		b_sent = i2c_master_recv(st->client, rxbuf, numvals);
	if (b_sent < 0)
		goto done;

	time_ns = iio_get_time_ns();

	memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));

	indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
done:
	kfree(rxbuf);
	atomic_dec(&st->protect_ring);
}


int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
	struct max1363_state *st = indio_dev->dev_data;
	int ret = 0;

	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, &max1363_poll_func_th);
	if (ret)
		goto error_deallocate_sw_rb;

	/* Ring buffer functions - here trigger setup related */
	indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs;
	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
	indio_dev->ring->preenable = &max1363_ring_preenable;
	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
	INIT_WORK(&st->poll_work, &max1363_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 max1363_ring_cleanup(struct iio_dev *indio_dev)
{
	/* ensure that the trigger has been detached */
	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);
}
Commit	Line	Data
0a1231df JC	1	/*
	2	* Copyright (C) 2008 Jonathan Cameron
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* max1363_ring.c
	9	*/
	10
	11	#include <linux/interrupt.h>
	12	#include <linux/gpio.h>
	13	#include <linux/workqueue.h>
	14	#include <linux/device.h>
5a0e3ad6	15	#include <linux/slab.h>
0a1231df JC	16	#include <linux/kernel.h>
	17	#include <linux/sysfs.h>
	18	#include <linux/list.h>
	19	#include <linux/i2c.h>
82020b0e	20	#include <linux/bitops.h>
0a1231df JC	21
	22	#include "../iio.h"
	23	#include "../ring_generic.h"
	24	#include "../ring_sw.h"
	25	#include "../trigger.h"
	26	#include "../sysfs.h"
	27
	28	#include "max1363.h"
	29
82020b0e JC	30	/* Todo: test this */
82020b0e JC	31	int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
0a1231df	32	{
bf32963c	33	struct iio_ring_buffer *ring = st->indio_dev->ring;
82020b0e JC	34	int count = 0, ret;
	35	u8 *ring_data;
	36	if (!(st->current_mode->modemask & mask)) {
	37	ret = -EBUSY;
	38	goto error_ret;
	39	}
0a1231df	40
e1517c00	41	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
0a1231df JC	42	if (ring_data == NULL) {
	43	ret = -ENOMEM;
	44	goto error_ret;
	45	}
bf32963c	46	ret = ring->access.read_last(ring, ring_data);
0a1231df JC	47	if (ret)
0a1231df JC	48	goto error_free_ring_data;
82020b0e JC	49	/* Need a count of channels prior to this one */
	50	mask >>= 1;
	51	while (mask) {
81b77f94	52	if (mask & st->current_mode->modemask)
82020b0e JC	53	count++;
	54	mask >>= 1;
	55	}
3bf877c1	56	if (st->chip_info->bits != 8)
81b77f94	57	ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8)
3bf877c1 JC	58	+ (int)(ring_data[count*2 + 1]);
3bf877c1 JC	59	else
81b77f94	60	ret = ring_data[count];
0a1231df JC	61
	62	error_free_ring_data:
	63	kfree(ring_data);
	64	error_ret:
	65	return ret;
	66	}
	67
	68	/**
c40ab874	69	* max1363_ring_preenable() - setup the parameters of the ring before enabling
0a1231df JC	70	*
	71	* The complex nature of the setting of the nuber of bytes per datum is due
	72	* to this driver currently ensuring that the timestamp is stored at an 8
	73	* byte boundary.
	74	**/
	75	static int max1363_ring_preenable(struct iio_dev *indio_dev)
	76	{
	77	struct max1363_state *st = indio_dev->dev_data;
bf32963c	78	struct iio_ring_buffer *ring = indio_dev->ring;
0a1231df	79	size_t d_size;
82020b0e JC	80	unsigned long numvals;
	81
	82	/*
	83	* Need to figure out the current mode based upon the requested
	84	* scan mask in iio_dev
	85	*/
bf32963c	86	st->current_mode = max1363_match_mode(ring->scan_mask,
82020b0e JC	87	st->chip_info);
	88	if (!st->current_mode)
	89	return -EINVAL;
	90
	91	max1363_set_scan_mode(st);
0a1231df	92
82020b0e	93	numvals = hweight_long(st->current_mode->modemask);
bf32963c	94	if (ring->access.set_bytes_per_datum) {
3bf877c1 JC	95	if (st->chip_info->bits != 8)
	96	d_size = numvals*2 + sizeof(s64);
	97	else
	98	d_size = numvals + sizeof(s64);
0a1231df JC	99	if (d_size % 8)
0a1231df JC	100	d_size += 8 - (d_size % 8);
bf32963c	101	ring->access.set_bytes_per_datum(ring, d_size);
0a1231df JC	102	}
	103
	104	return 0;
	105	}
	106
0a1231df JC	107
0a1231df JC	108	/**
c40ab874	109	* max1363_poll_func_th() - th of trigger launched polling to ring buffer
0a1231df	110	*
25985edc	111	* As sampling only occurs on i2c comms occurring, leave timestamping until
0a1231df JC	112	* then. Some triggers will generate their own time stamp. Currently
	113	* there is no way of notifying them when no one cares.
	114	**/
7b2c33b1	115	static void max1363_poll_func_th(struct iio_dev *indio_dev, s64 time)
0a1231df JC	116	{
	117	struct max1363_state *st = indio_dev->dev_data;
	118
	119	schedule_work(&st->poll_work);
	120
	121	return;
	122	}
	123	/**
c40ab874	124	* max1363_poll_bh_to_ring() - bh of trigger launched polling to ring buffer
0a1231df JC	125	* @work_s: the work struct through which this was scheduled
	126	*
	127	* Currently there is no option in this driver to disable the saving of
	128	* timestamps within the ring.
	129	* I think the one copy of this at a time was to avoid problems if the
	130	* trigger was set far too high and the reads then locked up the computer.
	131	**/
	132	static void max1363_poll_bh_to_ring(struct work_struct *work_s)
	133	{
	134	struct max1363_state *st = container_of(work_s, struct max1363_state,
	135	poll_work);
	136	struct iio_dev *indio_dev = st->indio_dev;
bf32963c	137	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
0a1231df JC	138	s64 time_ns;
	139	__u8 *rxbuf;
	140	int b_sent;
	141	size_t d_size;
82020b0e	142	unsigned long numvals = hweight_long(st->current_mode->modemask);
0a1231df JC	143
0a1231df JC	144	/* Ensure the timestamp is 8 byte aligned */
3bf877c1 JC	145	if (st->chip_info->bits != 8)
	146	d_size = numvals*2 + sizeof(s64);
	147	else
	148	d_size = numvals + sizeof(s64);
0a1231df JC	149	if (d_size % sizeof(s64))
	150	d_size += sizeof(s64) - (d_size % sizeof(s64));
	151
	152	/* Ensure only one copy of this function running at a time */
	153	if (atomic_inc_return(&st->protect_ring) > 1)
	154	return;
	155
	156	/* Monitor mode prevents reading. Whilst not currently implemented
	157	* might as well have this test in here in the meantime as it does
	158	* no harm.
	159	*/
82020b0e	160	if (numvals == 0)
0a1231df JC	161	return;
	162
	163	rxbuf = kmalloc(d_size, GFP_KERNEL);
	164	if (rxbuf == NULL)
	165	return;
3bf877c1 JC	166	if (st->chip_info->bits != 8)
	167	b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
	168	else
	169	b_sent = i2c_master_recv(st->client, rxbuf, numvals);
0a1231df JC	170	if (b_sent < 0)
	171	goto done;
	172
	173	time_ns = iio_get_time_ns();
	174
	175	memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
	176
bf32963c	177	indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
0a1231df JC	178	done:
	179	kfree(rxbuf);
	180	atomic_dec(&st->protect_ring);
	181	}
	182
	183
	184	int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
	185	{
	186	struct max1363_state *st = indio_dev->dev_data;
	187	int ret = 0;
	188
	189	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
	190	if (!indio_dev->ring) {
	191	ret = -ENOMEM;
	192	goto error_ret;
	193	}
	194	/* Effectively select the ring buffer implementation */
bf32963c	195	iio_ring_sw_register_funcs(&indio_dev->ring->access);
15744090 JC	196	ret = iio_alloc_pollfunc(indio_dev, NULL, &max1363_poll_func_th);
15744090 JC	197	if (ret)
0a1231df	198	goto error_deallocate_sw_rb;
0a1231df JC	199
0a1231df JC	200	/* Ring buffer functions - here trigger setup related */
bf32963c	201	indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs;
c3db00cc	202	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
0a1231df	203	indio_dev->ring->preenable = &max1363_ring_preenable;
c3db00cc	204	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
0a1231df JC	205	INIT_WORK(&st->poll_work, &max1363_poll_bh_to_ring);
	206
	207	/* Flag that polled ring buffering is possible */
	208	indio_dev->modes \|= INDIO_RING_TRIGGERED;
	209	return 0;
	210	error_deallocate_sw_rb:
	211	iio_sw_rb_free(indio_dev->ring);
	212	error_ret:
	213	return ret;
	214	}
	215
	216	void max1363_ring_cleanup(struct iio_dev *indio_dev)
	217	{
	218	/* ensure that the trigger has been detached */
	219	if (indio_dev->trig) {
	220	iio_put_trigger(indio_dev->trig);
	221	iio_trigger_dettach_poll_func(indio_dev->trig,
	222	indio_dev->pollfunc);
	223	}
	224	kfree(indio_dev->pollfunc);
	225	iio_sw_rb_free(indio_dev->ring);
	226	}