[linux-2.6-block.git] / drivers / w1 / slaves / w1_ds2413.c

/*
 * w1_ds2413.c - w1 family 3a (DS2413) driver
 * based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
 *
 * Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2. See the file COPYING for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include <linux/w1.h>

#define W1_FAMILY_DS2413	0x3A

#define W1_F3A_RETRIES                     3
#define W1_F3A_FUNC_PIO_ACCESS_READ        0xF5
#define W1_F3A_FUNC_PIO_ACCESS_WRITE       0x5A
#define W1_F3A_SUCCESS_CONFIRM_BYTE        0xAA

static ssize_t state_read(struct file *filp, struct kobject *kobj,
			  struct bin_attribute *bin_attr, char *buf, loff_t off,
			  size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	dev_dbg(&sl->dev,
		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);

	if (off != 0)
		return 0;
	if (!buf)
		return -EINVAL;

	mutex_lock(&sl->master->bus_mutex);
	dev_dbg(&sl->dev, "mutex locked");

	if (w1_reset_select_slave(sl)) {
		mutex_unlock(&sl->master->bus_mutex);
		return -EIO;
	}

	w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
	*buf = w1_read_8(sl->master);

	mutex_unlock(&sl->master->bus_mutex);
	dev_dbg(&sl->dev, "mutex unlocked");

	/* check for correct complement */
	if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
		return -EIO;
	else
		return 1;
}

static BIN_ATTR_RO(state, 1);

static ssize_t output_write(struct file *filp, struct kobject *kobj,
			    struct bin_attribute *bin_attr, char *buf,
			    loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	u8 w1_buf[3];
	unsigned int retries = W1_F3A_RETRIES;

	if (count != 1 || off != 0)
		return -EFAULT;

	dev_dbg(&sl->dev, "locking mutex for write_output");
	mutex_lock(&sl->master->bus_mutex);
	dev_dbg(&sl->dev, "mutex locked");

	if (w1_reset_select_slave(sl))
		goto error;

	/* according to the DS2413 datasheet the most significant 6 bits
	   should be set to "1"s, so do it now */
	*buf = *buf | 0xFC;

	while (retries--) {
		w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
		w1_buf[1] = *buf;
		w1_buf[2] = ~(*buf);
		w1_write_block(sl->master, w1_buf, 3);

		if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
			mutex_unlock(&sl->master->bus_mutex);
			dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
			return 1;
		}
		if (w1_reset_resume_command(sl->master))
			goto error;
	}

error:
	mutex_unlock(&sl->master->bus_mutex);
	dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
	return -EIO;
}

static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);

static struct bin_attribute *w1_f3a_bin_attrs[] = {
	&bin_attr_state,
	&bin_attr_output,
	NULL,
};

static const struct attribute_group w1_f3a_group = {
	.bin_attrs = w1_f3a_bin_attrs,
};

static const struct attribute_group *w1_f3a_groups[] = {
	&w1_f3a_group,
	NULL,
};

static struct w1_family_ops w1_f3a_fops = {
	.groups		= w1_f3a_groups,
};

static struct w1_family w1_family_3a = {
	.fid = W1_FAMILY_DS2413,
	.fops = &w1_f3a_fops,
};
module_w1_family(w1_family_3a);

MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));
Commit	Line	Data
31b4ca3e MB	1	/*
	2	* w1_ds2413.c - w1 family 3a (DS2413) driver
	3	* based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
	4	*
	5	* Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
	6	*
	7	* This source code is licensed under the GNU General Public License,
	8	* Version 2. See the file COPYING for more details.
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/moduleparam.h>
	14	#include <linux/device.h>
	15	#include <linux/types.h>
	16	#include <linux/delay.h>
	17	#include <linux/slab.h>
	18
de0d6dbd AD	19	#include <linux/w1.h>
	20
	21	#define W1_FAMILY_DS2413 0x3A
31b4ca3e	22
31b4ca3e MB	23	#define W1_F3A_RETRIES 3
	24	#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
	25	#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
	26	#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
	27
729fb9d3 GKH	28	static ssize_t state_read(struct file filp, struct kobject kobj,
	29	struct bin_attribute bin_attr, char buf, loff_t off,
	30	size_t count)
31b4ca3e MB	31	{
	32	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	33	dev_dbg(&sl->dev,
	34	"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
	35	bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
	36
	37	if (off != 0)
	38	return 0;
	39	if (!buf)
	40	return -EINVAL;
	41
	42	mutex_lock(&sl->master->bus_mutex);
	43	dev_dbg(&sl->dev, "mutex locked");
	44
	45	if (w1_reset_select_slave(sl)) {
	46	mutex_unlock(&sl->master->bus_mutex);
	47	return -EIO;
	48	}
	49
	50	w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
	51	*buf = w1_read_8(sl->master);
	52
	53	mutex_unlock(&sl->master->bus_mutex);
	54	dev_dbg(&sl->dev, "mutex unlocked");
	55
	56	/* check for correct complement */
	57	if ((buf & 0x0F) != ((~buf >> 4) & 0x0F))
	58	return -EIO;
	59	else
	60	return 1;
	61	}
	62
729fb9d3 GKH	63	static BIN_ATTR_RO(state, 1);
	64
	65	static ssize_t output_write(struct file filp, struct kobject kobj,
	66	struct bin_attribute bin_attr, char buf,
	67	loff_t off, size_t count)
31b4ca3e MB	68	{
	69	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	70	u8 w1_buf[3];
	71	unsigned int retries = W1_F3A_RETRIES;
	72
	73	if (count != 1 \|\| off != 0)
	74	return -EFAULT;
	75
	76	dev_dbg(&sl->dev, "locking mutex for write_output");
	77	mutex_lock(&sl->master->bus_mutex);
	78	dev_dbg(&sl->dev, "mutex locked");
	79
	80	if (w1_reset_select_slave(sl))
	81	goto error;
	82
	83	/* according to the DS2413 datasheet the most significant 6 bits
	84	should be set to "1"s, so do it now */
	85	buf = buf \| 0xFC;
	86
	87	while (retries--) {
	88	w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
	89	w1_buf[1] = *buf;
	90	w1_buf[2] = ~(*buf);
	91	w1_write_block(sl->master, w1_buf, 3);
	92
	93	if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
	94	mutex_unlock(&sl->master->bus_mutex);
	95	dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
	96	return 1;
	97	}
	98	if (w1_reset_resume_command(sl->master))
	99	goto error;
	100	}
	101
	102	error:
	103	mutex_unlock(&sl->master->bus_mutex);
	104	dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
	105	return -EIO;
	106	}
	107
729fb9d3 GKH	108	static BIN_ATTR(output, S_IRUGO \| S_IWUSR \| S_IWGRP, NULL, output_write, 1);
	109
	110	static struct bin_attribute *w1_f3a_bin_attrs[] = {
	111	&bin_attr_state,
	112	&bin_attr_output,
	113	NULL,
31b4ca3e MB	114	};
31b4ca3e MB	115
729fb9d3 GKH	116	static const struct attribute_group w1_f3a_group = {
	117	.bin_attrs = w1_f3a_bin_attrs,
	118	};
31b4ca3e	119
729fb9d3 GKH	120	static const struct attribute_group *w1_f3a_groups[] = {
	121	&w1_f3a_group,
	122	NULL,
	123	};
31b4ca3e MB	124
31b4ca3e MB	125	static struct w1_family_ops w1_f3a_fops = {
729fb9d3	126	.groups = w1_f3a_groups,
31b4ca3e MB	127	};
	128
	129	static struct w1_family w1_family_3a = {
	130	.fid = W1_FAMILY_DS2413,
	131	.fops = &w1_f3a_fops,
	132	};
939fc832	133	module_w1_family(w1_family_3a);
50fa2951 AD	134
	135	MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
	136	MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
	137	MODULE_LICENSE("GPL");
	138	MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));