LXR linux/drivers/w1/slaves/w1

   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#include <linux/gfp.h>
  20
  21#include <linux/w1.h>
  22
  23#include "w1_ds2760.h"
  24
  25#define W1_FAMILY_DS2760        0x30
  26
  27static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
  28                        int io)
  29{
  30        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  31
  32        if (!dev)
  33                return 0;
  34
  35        mutex_lock(&sl->master->bus_mutex);
  36
  37        if (addr > DS2760_DATA_SIZE || addr < 0) {
  38                count = 0;
  39                goto out;
  40        }
  41        if (addr + count > DS2760_DATA_SIZE)
  42                count = DS2760_DATA_SIZE - addr;
  43
  44        if (!w1_reset_select_slave(sl)) {
  45                if (!io) {
  46                        w1_write_8(sl->master, W1_DS2760_READ_DATA);
  47                        w1_write_8(sl->master, addr);
  48                        count = w1_read_block(sl->master, buf, count);
  49                } else {
  50                        w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
  51                        w1_write_8(sl->master, addr);
  52                        w1_write_block(sl->master, buf, count);
  53                        /* XXX w1_write_block returns void, not n_written */
  54                }
  55        }
  56
  57out:
  58        mutex_unlock(&sl->master->bus_mutex);
  59
  60        return count;
  61}
  62
  63int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
  64{
  65        return w1_ds2760_io(dev, buf, addr, count, 0);
  66}
  67EXPORT_SYMBOL(w1_ds2760_read);
  68
  69int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
  70{
  71        return w1_ds2760_io(dev, buf, addr, count, 1);
  72}
  73EXPORT_SYMBOL(w1_ds2760_write);
  74
  75static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
  76{
  77        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  78
  79        if (!dev)
  80                return -EINVAL;
  81
  82        mutex_lock(&sl->master->bus_mutex);
  83
  84        if (w1_reset_select_slave(sl) == 0) {
  85                w1_write_8(sl->master, cmd);
  86                w1_write_8(sl->master, addr);
  87        }
  88
  89        mutex_unlock(&sl->master->bus_mutex);
  90        return 0;
  91}
  92
  93int w1_ds2760_store_eeprom(struct device *dev, int addr)
  94{
  95        return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
  96}
  97EXPORT_SYMBOL(w1_ds2760_store_eeprom);
  98
  99int w1_ds2760_recall_eeprom(struct device *dev, int addr)
 100{
 101        return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
 102}
 103EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
 104
 105static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
 106                             struct bin_attribute *bin_attr, char *buf,
 107                             loff_t off, size_t count)
 108{
 109        struct device *dev = container_of(kobj, struct device, kobj);
 110        return w1_ds2760_read(dev, buf, off, count);
 111}
 112
 113static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
 114
 115static struct bin_attribute *w1_ds2760_bin_attrs[] = {
 116        &bin_attr_w1_slave,
 117        NULL,
 118};
 119
 120static const struct attribute_group w1_ds2760_group = {
 121        .bin_attrs = w1_ds2760_bin_attrs,
 122};
 123
 124static const struct attribute_group *w1_ds2760_groups[] = {
 125        &w1_ds2760_group,
 126        NULL,
 127};
 128
 129static int w1_ds2760_add_slave(struct w1_slave *sl)
 130{
 131        int ret;
 132        struct platform_device *pdev;
 133
 134        pdev = platform_device_alloc("ds2760-battery", PLATFORM_DEVID_AUTO);
 135        if (!pdev)
 136                return -ENOMEM;
 137        pdev->dev.parent = &sl->dev;
 138
 139        ret = platform_device_add(pdev);
 140        if (ret)
 141                goto pdev_add_failed;
 142
 143        dev_set_drvdata(&sl->dev, pdev);
 144
 145        return 0;
 146
 147pdev_add_failed:
 148        platform_device_put(pdev);
 149
 150        return ret;
 151}
 152
 153static void w1_ds2760_remove_slave(struct w1_slave *sl)
 154{
 155        struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 156
 157        platform_device_unregister(pdev);
 158}
 159
 160static struct w1_family_ops w1_ds2760_fops = {
 161        .add_slave    = w1_ds2760_add_slave,
 162        .remove_slave = w1_ds2760_remove_slave,
 163        .groups       = w1_ds2760_groups,
 164};
 165
 166static struct w1_family w1_ds2760_family = {
 167        .fid = W1_FAMILY_DS2760,
 168        .fops = &w1_ds2760_fops,
 169};
 170module_w1_family(w1_ds2760_family);
 171
 172MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
 173MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
 174MODULE_LICENSE("GPL");
 175MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));
 176