[deliverable/linux.git] / drivers / w1 / slaves / w1_ds2760.c

/*
 * 1-Wire implementation for the ds2760 chip
 *
 * Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/idr.h>

#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"
#include "w1_ds2760.h"

static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
			int io)
{
	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

	if (!dev)
		return 0;

	mutex_lock(&sl->master->mutex);

	if (addr > DS2760_DATA_SIZE || addr < 0) {
		count = 0;
		goto out;
	}
	if (addr + count > DS2760_DATA_SIZE)
		count = DS2760_DATA_SIZE - addr;

	if (!w1_reset_select_slave(sl)) {
		if (!io) {
			w1_write_8(sl->master, W1_DS2760_READ_DATA);
			w1_write_8(sl->master, addr);
			count = w1_read_block(sl->master, buf, count);
		} else {
			w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
			w1_write_8(sl->master, addr);
			w1_write_block(sl->master, buf, count);
			/* XXX w1_write_block returns void, not n_written */
		}
	}

out:
	mutex_unlock(&sl->master->mutex);

	return count;
}

int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
{
	return w1_ds2760_io(dev, buf, addr, count, 0);
}

int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
{
	return w1_ds2760_io(dev, buf, addr, count, 1);
}

static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
{
	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

	if (!dev)
		return -EINVAL;

	mutex_lock(&sl->master->mutex);

	if (w1_reset_select_slave(sl) == 0) {
		w1_write_8(sl->master, cmd);
		w1_write_8(sl->master, addr);
	}

	mutex_unlock(&sl->master->mutex);
	return 0;
}

int w1_ds2760_store_eeprom(struct device *dev, int addr)
{
	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
}

int w1_ds2760_recall_eeprom(struct device *dev, int addr)
{
	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
}

static ssize_t w1_ds2760_read_bin(struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *buf, loff_t off, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	return w1_ds2760_read(dev, buf, off, count);
}

static struct bin_attribute w1_ds2760_bin_attr = {
	.attr = {
		.name = "w1_slave",
		.mode = S_IRUGO,
	},
	.size = DS2760_DATA_SIZE,
	.read = w1_ds2760_read_bin,
};

static DEFINE_IDR(bat_idr);
static DEFINE_MUTEX(bat_idr_lock);

static int new_bat_id(void)
{
	int ret;

	while (1) {
		int id;

		ret = idr_pre_get(&bat_idr, GFP_KERNEL);
		if (ret == 0)
			return -ENOMEM;

		mutex_lock(&bat_idr_lock);
		ret = idr_get_new(&bat_idr, NULL, &id);
		mutex_unlock(&bat_idr_lock);

		if (ret == 0) {
			ret = id & MAX_ID_MASK;
			break;
		} else if (ret == -EAGAIN) {
			continue;
		} else {
			break;
		}
	}

	return ret;
}

static void release_bat_id(int id)
{
	mutex_lock(&bat_idr_lock);
	idr_remove(&bat_idr, id);
	mutex_unlock(&bat_idr_lock);
}

static int w1_ds2760_add_slave(struct w1_slave *sl)
{
	int ret;
	int id;
	struct platform_device *pdev;

	id = new_bat_id();
	if (id < 0) {
		ret = id;
		goto noid;
	}

	pdev = platform_device_alloc("ds2760-battery", id);
	if (!pdev) {
		ret = -ENOMEM;
		goto pdev_alloc_failed;
	}
	pdev->dev.parent = &sl->dev;

	ret = platform_device_add(pdev);
	if (ret)
		goto pdev_add_failed;

	ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
	if (ret)
		goto bin_attr_failed;

	dev_set_drvdata(&sl->dev, pdev);

	goto success;

bin_attr_failed:
pdev_add_failed:
	platform_device_unregister(pdev);
pdev_alloc_failed:
	release_bat_id(id);
noid:
success:
	return ret;
}

static void w1_ds2760_remove_slave(struct w1_slave *sl)
{
	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
	int id = pdev->id;

	platform_device_unregister(pdev);
	release_bat_id(id);
	sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
}

static struct w1_family_ops w1_ds2760_fops = {
	.add_slave    = w1_ds2760_add_slave,
	.remove_slave = w1_ds2760_remove_slave,
};

static struct w1_family w1_ds2760_family = {
	.fid = W1_FAMILY_DS2760,
	.fops = &w1_ds2760_fops,
};

static int __init w1_ds2760_init(void)
{
	printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
	       " chip  - (c) 2004-2005, Szabolcs Gyurko\n");
	idr_init(&bat_idr);
	return w1_register_family(&w1_ds2760_family);
}

static void __exit w1_ds2760_exit(void)
{
	w1_unregister_family(&w1_ds2760_family);
	idr_destroy(&bat_idr);
}

EXPORT_SYMBOL(w1_ds2760_read);
EXPORT_SYMBOL(w1_ds2760_write);
EXPORT_SYMBOL(w1_ds2760_store_eeprom);
EXPORT_SYMBOL(w1_ds2760_recall_eeprom);

module_init(w1_ds2760_init);
module_exit(w1_ds2760_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
Commit	Line	Data
d7ce6d1d AV	1	/*
	2	* 1-Wire implementation for the ds2760 chip
	3	*
	4	* Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
	5	*
	6	* Use consistent with the GNU GPL is permitted,
	7	* provided that this copyright notice is
	8	* preserved in its entirety in all copies and derived works.
	9	*
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/device.h>
	15	#include <linux/types.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/mutex.h>
	18	#include <linux/idr.h>
	19
	20	#include "../w1.h"
	21	#include "../w1_int.h"
	22	#include "../w1_family.h"
	23	#include "w1_ds2760.h"
	24
	25	static int w1_ds2760_io(struct device dev, char buf, int addr, size_t count,
	26	int io)
	27	{
	28	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
	29
	30	if (!dev)
	31	return 0;
	32
	33	mutex_lock(&sl->master->mutex);
	34
	35	if (addr > DS2760_DATA_SIZE \|\| addr < 0) {
	36	count = 0;
	37	goto out;
	38	}
	39	if (addr + count > DS2760_DATA_SIZE)
	40	count = DS2760_DATA_SIZE - addr;
	41
	42	if (!w1_reset_select_slave(sl)) {
	43	if (!io) {
	44	w1_write_8(sl->master, W1_DS2760_READ_DATA);
	45	w1_write_8(sl->master, addr);
	46	count = w1_read_block(sl->master, buf, count);
	47	} else {
	48	w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
	49	w1_write_8(sl->master, addr);
	50	w1_write_block(sl->master, buf, count);
	51	/* XXX w1_write_block returns void, not n_written */
	52	}
	53	}
	54
	55	out:
	56	mutex_unlock(&sl->master->mutex);
	57
	58	return count;
	59	}
	60
	61	int w1_ds2760_read(struct device dev, char buf, int addr, size_t count)
	62	{
	63	return w1_ds2760_io(dev, buf, addr, count, 0);
	64	}
65
66	int w1_ds2760_write(struct device dev, char buf, int addr, size_t count)
67	{
68	return w1_ds2760_io(dev, buf, addr, count, 1);
69	}
70
0b47b570 DM	71	static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
	72	{
	73	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
	74
	75	if (!dev)
	76	return -EINVAL;
	77
	78	mutex_lock(&sl->master->mutex);
	79
	80	if (w1_reset_select_slave(sl) == 0) {
	81	w1_write_8(sl->master, cmd);
	82	w1_write_8(sl->master, addr);
	83	}
	84
	85	mutex_unlock(&sl->master->mutex);
	86	return 0;
	87	}
	88
	89	int w1_ds2760_store_eeprom(struct device *dev, int addr)
	90	{
	91	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
	92	}
	93
	94	int w1_ds2760_recall_eeprom(struct device *dev, int addr)
	95	{
	96	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
	97	}
	98
0909fca5 AM	99	static ssize_t w1_ds2760_read_bin(struct kobject *kobj,
	100	struct bin_attribute *bin_attr,
	101	char *buf, loff_t off, size_t count)
d7ce6d1d AV	102	{
	103	struct device *dev = container_of(kobj, struct device, kobj);
	104	return w1_ds2760_read(dev, buf, off, count);
	105	}
	106
	107	static struct bin_attribute w1_ds2760_bin_attr = {
	108	.attr = {
	109	.name = "w1_slave",
	110	.mode = S_IRUGO,
d7ce6d1d AV	111	},
	112	.size = DS2760_DATA_SIZE,
	113	.read = w1_ds2760_read_bin,
	114	};
	115
	116	static DEFINE_IDR(bat_idr);
	117	static DEFINE_MUTEX(bat_idr_lock);
	118
	119	static int new_bat_id(void)
	120	{
	121	int ret;
	122
	123	while (1) {
	124	int id;
	125
	126	ret = idr_pre_get(&bat_idr, GFP_KERNEL);
	127	if (ret == 0)
	128	return -ENOMEM;
	129
	130	mutex_lock(&bat_idr_lock);
	131	ret = idr_get_new(&bat_idr, NULL, &id);
	132	mutex_unlock(&bat_idr_lock);
	133
	134	if (ret == 0) {
	135	ret = id & MAX_ID_MASK;
	136	break;
	137	} else if (ret == -EAGAIN) {
	138	continue;
	139	} else {
	140	break;
	141	}
	142	}
	143
	144	return ret;
	145	}
	146
	147	static void release_bat_id(int id)
	148	{
	149	mutex_lock(&bat_idr_lock);
	150	idr_remove(&bat_idr, id);
	151	mutex_unlock(&bat_idr_lock);
d7ce6d1d AV	152	}
	153
	154	static int w1_ds2760_add_slave(struct w1_slave *sl)
	155	{
	156	int ret;
	157	int id;
	158	struct platform_device *pdev;
	159
	160	id = new_bat_id();
	161	if (id < 0) {
	162	ret = id;
	163	goto noid;
	164	}
	165
	166	pdev = platform_device_alloc("ds2760-battery", id);
	167	if (!pdev) {
	168	ret = -ENOMEM;
	169	goto pdev_alloc_failed;
	170	}
	171	pdev->dev.parent = &sl->dev;
	172
	173	ret = platform_device_add(pdev);
	174	if (ret)
	175	goto pdev_add_failed;
	176
	177	ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
	178	if (ret)
	179	goto bin_attr_failed;
	180
	181	dev_set_drvdata(&sl->dev, pdev);
	182
	183	goto success;
	184
	185	bin_attr_failed:
	186	pdev_add_failed:
	187	platform_device_unregister(pdev);
	188	pdev_alloc_failed:
	189	release_bat_id(id);
	190	noid:
	191	success:
	192	return ret;
	193	}
	194
	195	static void w1_ds2760_remove_slave(struct w1_slave *sl)
	196	{
	197	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
	198	int id = pdev->id;
	199
	200	platform_device_unregister(pdev);
	201	release_bat_id(id);
	202	sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
d7ce6d1d AV	203	}
	204
	205	static struct w1_family_ops w1_ds2760_fops = {
	206	.add_slave = w1_ds2760_add_slave,
	207	.remove_slave = w1_ds2760_remove_slave,
	208	};
	209
	210	static struct w1_family w1_ds2760_family = {
	211	.fid = W1_FAMILY_DS2760,
	212	.fops = &w1_ds2760_fops,
	213	};
	214
	215	static int __init w1_ds2760_init(void)
	216	{
	217	printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
	218	" chip - (c) 2004-2005, Szabolcs Gyurko\n");
	219	idr_init(&bat_idr);
	220	return w1_register_family(&w1_ds2760_family);
	221	}
	222
	223	static void __exit w1_ds2760_exit(void)
	224	{
	225	w1_unregister_family(&w1_ds2760_family);
	226	idr_destroy(&bat_idr);
	227	}
	228
	229	EXPORT_SYMBOL(w1_ds2760_read);
	230	EXPORT_SYMBOL(w1_ds2760_write);
0b47b570 DM	231	EXPORT_SYMBOL(w1_ds2760_store_eeprom);
0b47b570 DM	232	EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
d7ce6d1d AV	233
	234	module_init(w1_ds2760_init);
	235	module_exit(w1_ds2760_exit);
	236
	237	MODULE_LICENSE("GPL");
	238	MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
	239	MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");