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/*
* 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 ssize_t w1_ds2760_read_bin(struct kobject *kobj, 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,
.owner = THIS_MODULE,
},
.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);
return;
}
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);
return;
}
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);
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");
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