[linux-block.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 "../iio.h"
#include "../ring_generic.h"
#include "../ring_sw.h"
#include "../trigger.h"
#include "../sysfs.h"

#include "max1363.h"

ssize_t max1363_scan_from_ring(struct device *dev,
			       struct device_attribute *attr,
			       char *buf)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct max1363_state *info = dev_info->dev_data;
	int i, ret, len = 0;
	char *ring_data;

	ring_data = kmalloc(info->current_mode->numvals*2, GFP_KERNEL);
	if (ring_data == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}
	ret = dev_info->ring->access.read_last(dev_info->ring, ring_data);
	if (ret)
		goto error_free_ring_data;
	len += sprintf(buf+len, "ring ");
	for (i = 0; i < info->current_mode->numvals; i++)
		len += sprintf(buf + len, "%d ",
			       ((int)(ring_data[i*2 + 0] & 0x0F) << 8)
			       + ((int)(ring_data[i*2 + 1])));
	len += sprintf(buf + len, "\n");
	kfree(ring_data);

	return len;

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;
	size_t d_size;

	if (indio_dev->ring->access.set_bpd) {
		d_size = st->current_mode->numvals*2 + sizeof(s64);
		if (d_size % 8)
			d_size += 8 - (d_size % 8);
		indio_dev->ring->access.set_bpd(indio_dev->ring, d_size);
	}

	return 0;
}

/**
 * max1363_ring_postenable() typical ring post enable
 *
 * Only not moved into the core for the hardware ring buffer cases
 * that are more sophisticated.
 **/
static int max1363_ring_postenable(struct iio_dev *indio_dev)
{
	if (indio_dev->trig == NULL)
		return 0;
	return iio_trigger_attach_poll_func(indio_dev->trig,
					    indio_dev->pollfunc);
}

/**
 * max1363_ring_predisable() runs just prior to ring buffer being disabled
 *
 * Typical predisable function which ensures that no trigger events can
 * occur before we disable the ring buffer (and hence would have no idea
 * what to do with them)
 **/
static int max1363_ring_predisable(struct iio_dev *indio_dev)
{
	if (indio_dev->trig)
		return iio_trigger_dettach_poll_func(indio_dev->trig,
						     indio_dev->pollfunc);
	else
		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.
 **/
void max1363_poll_func_th(struct iio_dev *indio_dev)
{
	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 *ring = iio_to_sw_ring(indio_dev->ring);
	s64 time_ns;
	__u8 *rxbuf;
	int b_sent;
	size_t d_size;

	/* Ensure the timestamp is 8 byte aligned */
	d_size = st->current_mode->numvals*2 + 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 (st->current_mode->numvals == 0)
		return;

	rxbuf = kmalloc(d_size,	GFP_KERNEL);
	if (rxbuf == NULL)
		return;

	b_sent = i2c_master_recv(st->client,
				 rxbuf,
				 st->current_mode->numvals*2);
	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(&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(&st->indio_dev->ring->access);
	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
	if (indio_dev->pollfunc == NULL) {
		ret = -ENOMEM;
		goto error_deallocate_sw_rb;
	}
	/* Configure the polling function called on trigger interrupts */
	indio_dev->pollfunc->poll_func_main = &max1363_poll_func_th;
	indio_dev->pollfunc->private_data = indio_dev;

	/* Ring buffer functions - here trigger setup related */
	indio_dev->ring->postenable = &max1363_ring_postenable;
	indio_dev->ring->preenable = &max1363_ring_preenable;
	indio_dev->ring->predisable = &max1363_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);
}

void max1363_uninitialize_ring(struct iio_ring_buffer *ring)
{
	iio_ring_buffer_unregister(ring);
};

int max1363_initialize_ring(struct iio_ring_buffer *ring)
{
	return iio_ring_buffer_register(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>
	20
	21	#include "../iio.h"
	22	#include "../ring_generic.h"
	23	#include "../ring_sw.h"
	24	#include "../trigger.h"
	25	#include "../sysfs.h"
	26
	27	#include "max1363.h"
	28
	29	ssize_t max1363_scan_from_ring(struct device *dev,
	30	struct device_attribute *attr,
	31	char *buf)
	32	{
	33	struct iio_dev *dev_info = dev_get_drvdata(dev);
	34	struct max1363_state *info = dev_info->dev_data;
	35	int i, ret, len = 0;
	36	char *ring_data;
	37
	38	ring_data = kmalloc(info->current_mode->numvals*2, GFP_KERNEL);
	39	if (ring_data == NULL) {
	40	ret = -ENOMEM;
	41	goto error_ret;
	42	}
	43	ret = dev_info->ring->access.read_last(dev_info->ring, ring_data);
	44	if (ret)
	45	goto error_free_ring_data;
	46	len += sprintf(buf+len, "ring ");
	47	for (i = 0; i < info->current_mode->numvals; i++)
	48	len += sprintf(buf + len, "%d ",
	49	((int)(ring_data[i*2 + 0] & 0x0F) << 8)
	50	+ ((int)(ring_data[i*2 + 1])));
	51	len += sprintf(buf + len, "\n");
	52	kfree(ring_data);
	53
	54	return len;
	55
	56	error_free_ring_data:
	57	kfree(ring_data);
	58	error_ret:
	59	return ret;
	60	}
	61
	62	/**
	63	* max1363_ring_preenable() setup the parameters of the ring before enabling
	64	*
	65	* The complex nature of the setting of the nuber of bytes per datum is due
	66	* to this driver currently ensuring that the timestamp is stored at an 8
	67	* byte boundary.
	68	**/
	69	static int max1363_ring_preenable(struct iio_dev *indio_dev)
	70	{
	71	struct max1363_state *st = indio_dev->dev_data;
	72	size_t d_size;
	73
	74	if (indio_dev->ring->access.set_bpd) {
	75	d_size = st->current_mode->numvals*2 + sizeof(s64);
	76	if (d_size % 8)
	77	d_size += 8 - (d_size % 8);
	78	indio_dev->ring->access.set_bpd(indio_dev->ring, d_size);
	79	}
80
81	return 0;
82	}
83
84	/**
85	* max1363_ring_postenable() typical ring post enable
86	*
87	* Only not moved into the core for the hardware ring buffer cases
88	* that are more sophisticated.
89	**/
90	static int max1363_ring_postenable(struct iio_dev *indio_dev)
91	{
92	if (indio_dev->trig == NULL)
93	return 0;
94	return iio_trigger_attach_poll_func(indio_dev->trig,
95	indio_dev->pollfunc);
96	}
97
98	/**
99	* max1363_ring_predisable() runs just prior to ring buffer being disabled
100	*
101	* Typical predisable function which ensures that no trigger events can
102	* occur before we disable the ring buffer (and hence would have no idea
103	* what to do with them)
104	**/
105	static int max1363_ring_predisable(struct iio_dev *indio_dev)
106	{
107	if (indio_dev->trig)
108	return iio_trigger_dettach_poll_func(indio_dev->trig,
109	indio_dev->pollfunc);
110	else
111	return 0;
112	}
113
114	/**
115	* max1363_poll_func_th() th of trigger launched polling to ring buffer
116	*
117	* As sampling only occurs on i2c comms occuring, leave timestamping until
118	* then. Some triggers will generate their own time stamp. Currently
119	* there is no way of notifying them when no one cares.
120	**/
121	void max1363_poll_func_th(struct iio_dev *indio_dev)
122	{
123	struct max1363_state *st = indio_dev->dev_data;
124
125	schedule_work(&st->poll_work);
126
127	return;
128	}
129	/**
130	* max1363_poll_bh_to_ring() bh of trigger launched polling to ring buffer
131	* @work_s: the work struct through which this was scheduled
132	*
133	* Currently there is no option in this driver to disable the saving of
134	* timestamps within the ring.
135	* I think the one copy of this at a time was to avoid problems if the
136	* trigger was set far too high and the reads then locked up the computer.
137	**/
138	static void max1363_poll_bh_to_ring(struct work_struct *work_s)
139	{
140	struct max1363_state *st = container_of(work_s, struct max1363_state,
141	poll_work);
142	struct iio_dev *indio_dev = st->indio_dev;
143	struct iio_sw_ring_buffer *ring = iio_to_sw_ring(indio_dev->ring);
144	s64 time_ns;
145	__u8 *rxbuf;
146	int b_sent;
147	size_t d_size;
148
149	/* Ensure the timestamp is 8 byte aligned */
150	d_size = st->current_mode->numvals*2 + sizeof(s64);
151	if (d_size % sizeof(s64))
152	d_size += sizeof(s64) - (d_size % sizeof(s64));
153
154	/* Ensure only one copy of this function running at a time */
155	if (atomic_inc_return(&st->protect_ring) > 1)
156	return;
157
158	/* Monitor mode prevents reading. Whilst not currently implemented
159	* might as well have this test in here in the meantime as it does
160	* no harm.
161	*/
162	if (st->current_mode->numvals == 0)
163	return;
164
165	rxbuf = kmalloc(d_size, GFP_KERNEL);
166	if (rxbuf == NULL)
167	return;
168
169	b_sent = i2c_master_recv(st->client,
170	rxbuf,
171	st->current_mode->numvals*2);
172	if (b_sent < 0)
173	goto done;
174
175	time_ns = iio_get_time_ns();
176
177	memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
178
179	indio_dev->ring->access.store_to(&ring->buf, rxbuf, time_ns);
180	done:
181	kfree(rxbuf);
182	atomic_dec(&st->protect_ring);
183	}
184
185
186	int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
187	{
188	struct max1363_state *st = indio_dev->dev_data;
189	int ret = 0;
190
191	indio_dev->ring = iio_sw_rb_allocate(indio_dev);
192	if (!indio_dev->ring) {
193	ret = -ENOMEM;
194	goto error_ret;
195	}
196	/* Effectively select the ring buffer implementation */
197	iio_ring_sw_register_funcs(&st->indio_dev->ring->access);
198	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
199	if (indio_dev->pollfunc == NULL) {
200	ret = -ENOMEM;
201	goto error_deallocate_sw_rb;
202	}
203	/* Configure the polling function called on trigger interrupts */
204	indio_dev->pollfunc->poll_func_main = &max1363_poll_func_th;
205	indio_dev->pollfunc->private_data = indio_dev;
206
207	/* Ring buffer functions - here trigger setup related */
208	indio_dev->ring->postenable = &max1363_ring_postenable;
209	indio_dev->ring->preenable = &max1363_ring_preenable;
210	indio_dev->ring->predisable = &max1363_ring_predisable;
211	INIT_WORK(&st->poll_work, &max1363_poll_bh_to_ring);
212
213	/* Flag that polled ring buffering is possible */
214	indio_dev->modes \|= INDIO_RING_TRIGGERED;
215	return 0;
216	error_deallocate_sw_rb:
217	iio_sw_rb_free(indio_dev->ring);
218	error_ret:
219	return ret;
220	}
221
222	void max1363_ring_cleanup(struct iio_dev *indio_dev)
223	{
224	/* ensure that the trigger has been detached */
225	if (indio_dev->trig) {
226	iio_put_trigger(indio_dev->trig);
227	iio_trigger_dettach_poll_func(indio_dev->trig,
228	indio_dev->pollfunc);
229	}
230	kfree(indio_dev->pollfunc);
231	iio_sw_rb_free(indio_dev->ring);
232	}
233
234	void max1363_uninitialize_ring(struct iio_ring_buffer *ring)
235	{
236	iio_ring_buffer_unregister(ring);
237	};
238
239	int max1363_initialize_ring(struct iio_ring_buffer *ring)
240	{
241	return iio_ring_buffer_register(ring);
242	};