[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;
	unsigned long numvals;
	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 occuring, 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	unsigned long numvals;
	35	int count = 0, ret;
	36	u8 *ring_data;
	37	if (!(st->current_mode->modemask & mask)) {
	38	ret = -EBUSY;
	39	goto error_ret;
	40	}
0a1231df	41
e1517c00	42	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
0a1231df JC	43	if (ring_data == NULL) {
	44	ret = -ENOMEM;
	45	goto error_ret;
	46	}
bf32963c	47	ret = ring->access.read_last(ring, ring_data);
0a1231df JC	48	if (ret)
0a1231df JC	49	goto error_free_ring_data;
82020b0e JC	50	/* Need a count of channels prior to this one */
	51	mask >>= 1;
	52	while (mask) {
81b77f94	53	if (mask & st->current_mode->modemask)
82020b0e JC	54	count++;
	55	mask >>= 1;
	56	}
3bf877c1	57	if (st->chip_info->bits != 8)
81b77f94	58	ret = ((int)(ring_data[count*2 + 0] & 0x0F) << 8)
3bf877c1 JC	59	+ (int)(ring_data[count*2 + 1]);
3bf877c1 JC	60	else
81b77f94	61	ret = ring_data[count];
0a1231df JC	62
	63	error_free_ring_data:
	64	kfree(ring_data);
	65	error_ret:
	66	return ret;
	67	}
	68
	69	/**
c40ab874	70	* max1363_ring_preenable() - setup the parameters of the ring before enabling
0a1231df JC	71	*
	72	* The complex nature of the setting of the nuber of bytes per datum is due
	73	* to this driver currently ensuring that the timestamp is stored at an 8
	74	* byte boundary.
	75	**/
	76	static int max1363_ring_preenable(struct iio_dev *indio_dev)
	77	{
	78	struct max1363_state *st = indio_dev->dev_data;
bf32963c	79	struct iio_ring_buffer *ring = indio_dev->ring;
0a1231df	80	size_t d_size;
82020b0e JC	81	unsigned long numvals;
	82
	83	/*
	84	* Need to figure out the current mode based upon the requested
	85	* scan mask in iio_dev
	86	*/
bf32963c	87	st->current_mode = max1363_match_mode(ring->scan_mask,
82020b0e JC	88	st->chip_info);
	89	if (!st->current_mode)
	90	return -EINVAL;
	91
	92	max1363_set_scan_mode(st);
0a1231df	93
82020b0e	94	numvals = hweight_long(st->current_mode->modemask);
bf32963c	95	if (ring->access.set_bytes_per_datum) {
3bf877c1 JC	96	if (st->chip_info->bits != 8)
	97	d_size = numvals*2 + sizeof(s64);
	98	else
	99	d_size = numvals + sizeof(s64);
0a1231df JC	100	if (d_size % 8)
0a1231df JC	101	d_size += 8 - (d_size % 8);
bf32963c	102	ring->access.set_bytes_per_datum(ring, d_size);
0a1231df JC	103	}
	104
	105	return 0;
	106	}
	107
0a1231df JC	108
0a1231df JC	109	/**
c40ab874	110	* max1363_poll_func_th() - th of trigger launched polling to ring buffer
0a1231df JC	111	*
	112	* As sampling only occurs on i2c comms occuring, leave timestamping until
	113	* then. Some triggers will generate their own time stamp. Currently
	114	* there is no way of notifying them when no one cares.
	115	**/
7b2c33b1	116	static void max1363_poll_func_th(struct iio_dev *indio_dev, s64 time)
0a1231df JC	117	{
	118	struct max1363_state *st = indio_dev->dev_data;
	119
	120	schedule_work(&st->poll_work);
	121
	122	return;
	123	}
	124	/**
c40ab874	125	* max1363_poll_bh_to_ring() - bh of trigger launched polling to ring buffer
0a1231df JC	126	* @work_s: the work struct through which this was scheduled
	127	*
	128	* Currently there is no option in this driver to disable the saving of
	129	* timestamps within the ring.
	130	* I think the one copy of this at a time was to avoid problems if the
	131	* trigger was set far too high and the reads then locked up the computer.
	132	**/
	133	static void max1363_poll_bh_to_ring(struct work_struct *work_s)
	134	{
	135	struct max1363_state *st = container_of(work_s, struct max1363_state,
	136	poll_work);
	137	struct iio_dev *indio_dev = st->indio_dev;
bf32963c	138	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
0a1231df JC	139	s64 time_ns;
	140	__u8 *rxbuf;
	141	int b_sent;
	142	size_t d_size;
82020b0e	143	unsigned long numvals = hweight_long(st->current_mode->modemask);
0a1231df JC	144
0a1231df JC	145	/* Ensure the timestamp is 8 byte aligned */
3bf877c1 JC	146	if (st->chip_info->bits != 8)
	147	d_size = numvals*2 + sizeof(s64);
	148	else
	149	d_size = numvals + sizeof(s64);
0a1231df JC	150	if (d_size % sizeof(s64))
	151	d_size += sizeof(s64) - (d_size % sizeof(s64));
	152
	153	/* Ensure only one copy of this function running at a time */
	154	if (atomic_inc_return(&st->protect_ring) > 1)
	155	return;
	156
	157	/* Monitor mode prevents reading. Whilst not currently implemented
	158	* might as well have this test in here in the meantime as it does
	159	* no harm.
	160	*/
82020b0e	161	if (numvals == 0)
0a1231df JC	162	return;
	163
	164	rxbuf = kmalloc(d_size, GFP_KERNEL);
	165	if (rxbuf == NULL)
	166	return;
3bf877c1 JC	167	if (st->chip_info->bits != 8)
	168	b_sent = i2c_master_recv(st->client, rxbuf, numvals*2);
	169	else
	170	b_sent = i2c_master_recv(st->client, rxbuf, numvals);
0a1231df JC	171	if (b_sent < 0)
	172	goto done;
	173
	174	time_ns = iio_get_time_ns();
	175
	176	memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
	177
bf32963c	178	indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
0a1231df JC	179	done:
	180	kfree(rxbuf);
	181	atomic_dec(&st->protect_ring);
	182	}
	183
	184
	185	int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
	186	{
	187	struct max1363_state *st = indio_dev->dev_data;
	188	int ret = 0;
	189
	190	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
	191	if (!indio_dev->ring) {
	192	ret = -ENOMEM;
	193	goto error_ret;
	194	}
	195	/* Effectively select the ring buffer implementation */
bf32963c	196	iio_ring_sw_register_funcs(&indio_dev->ring->access);
15744090 JC	197	ret = iio_alloc_pollfunc(indio_dev, NULL, &max1363_poll_func_th);
15744090 JC	198	if (ret)
0a1231df	199	goto error_deallocate_sw_rb;
0a1231df JC	200
0a1231df JC	201	/* Ring buffer functions - here trigger setup related */
bf32963c	202	indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs;
c3db00cc	203	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
0a1231df	204	indio_dev->ring->preenable = &max1363_ring_preenable;
c3db00cc	205	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
0a1231df JC	206	INIT_WORK(&st->poll_work, &max1363_poll_bh_to_ring);
	207
	208	/* Flag that polled ring buffering is possible */
	209	indio_dev->modes \|= INDIO_RING_TRIGGERED;
	210	return 0;
	211	error_deallocate_sw_rb:
	212	iio_sw_rb_free(indio_dev->ring);
	213	error_ret:
	214	return ret;
	215	}
	216
	217	void max1363_ring_cleanup(struct iio_dev *indio_dev)
	218	{
	219	/* ensure that the trigger has been detached */
	220	if (indio_dev->trig) {
	221	iio_put_trigger(indio_dev->trig);
	222	iio_trigger_dettach_poll_func(indio_dev->trig,
	223	indio_dev->pollfunc);
	224	}
	225	kfree(indio_dev->pollfunc);
	226	iio_sw_rb_free(indio_dev->ring);
	227	}