linux/drivers/w1/slaves/w1_ds2780.c
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   1/*
   2 * 1-Wire implementation for the ds2780 chip
   3 *
   4 * Copyright (C) 2010 Indesign, LLC
   5 *
   6 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
   7 *
   8 * Based on w1-ds2760 driver
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License version 2 as
  12 * published by the Free Software Foundation.
  13 *
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/device.h>
  19#include <linux/types.h>
  20#include <linux/platform_device.h>
  21#include <linux/mutex.h>
  22#include <linux/idr.h>
  23
  24#include "../w1.h"
  25#include "../w1_int.h"
  26#include "../w1_family.h"
  27#include "w1_ds2780.h"
  28
  29static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
  30                        size_t count, int io)
  31{
  32        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  33
  34        if (addr > DS2780_DATA_SIZE || addr < 0)
  35                return 0;
  36
  37        count = min_t(int, count, DS2780_DATA_SIZE - addr);
  38
  39        if (w1_reset_select_slave(sl) == 0) {
  40                if (io) {
  41                        w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
  42                        w1_write_8(sl->master, addr);
  43                        w1_write_block(sl->master, buf, count);
  44                } else {
  45                        w1_write_8(sl->master, W1_DS2780_READ_DATA);
  46                        w1_write_8(sl->master, addr);
  47                        count = w1_read_block(sl->master, buf, count);
  48                }
  49        }
  50
  51        return count;
  52}
  53
  54int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  55                        int io)
  56{
  57        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  58        int ret;
  59
  60        if (!dev)
  61                return -ENODEV;
  62
  63        mutex_lock(&sl->master->bus_mutex);
  64
  65        ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  66
  67        mutex_unlock(&sl->master->bus_mutex);
  68
  69        return ret;
  70}
  71EXPORT_SYMBOL(w1_ds2780_io);
  72
  73int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
  74{
  75        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  76
  77        if (!dev)
  78                return -EINVAL;
  79
  80        mutex_lock(&sl->master->bus_mutex);
  81
  82        if (w1_reset_select_slave(sl) == 0) {
  83                w1_write_8(sl->master, cmd);
  84                w1_write_8(sl->master, addr);
  85        }
  86
  87        mutex_unlock(&sl->master->bus_mutex);
  88        return 0;
  89}
  90EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
  91
  92static ssize_t w1_ds2780_read_bin(struct file *filp,
  93                                  struct kobject *kobj,
  94                                  struct bin_attribute *bin_attr,
  95                                  char *buf, loff_t off, size_t count)
  96{
  97        struct device *dev = container_of(kobj, struct device, kobj);
  98        return w1_ds2780_io(dev, buf, off, count, 0);
  99}
 100
 101static struct bin_attribute w1_ds2780_bin_attr = {
 102        .attr = {
 103                .name = "w1_slave",
 104                .mode = S_IRUGO,
 105        },
 106        .size = DS2780_DATA_SIZE,
 107        .read = w1_ds2780_read_bin,
 108};
 109
 110static DEFINE_IDA(bat_ida);
 111
 112static int w1_ds2780_add_slave(struct w1_slave *sl)
 113{
 114        int ret;
 115        int id;
 116        struct platform_device *pdev;
 117
 118        id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
 119        if (id < 0) {
 120                ret = id;
 121                goto noid;
 122        }
 123
 124        pdev = platform_device_alloc("ds2780-battery", id);
 125        if (!pdev) {
 126                ret = -ENOMEM;
 127                goto pdev_alloc_failed;
 128        }
 129        pdev->dev.parent = &sl->dev;
 130
 131        ret = platform_device_add(pdev);
 132        if (ret)
 133                goto pdev_add_failed;
 134
 135        ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
 136        if (ret)
 137                goto bin_attr_failed;
 138
 139        dev_set_drvdata(&sl->dev, pdev);
 140
 141        return 0;
 142
 143bin_attr_failed:
 144        platform_device_del(pdev);
 145pdev_add_failed:
 146        platform_device_put(pdev);
 147pdev_alloc_failed:
 148        ida_simple_remove(&bat_ida, id);
 149noid:
 150        return ret;
 151}
 152
 153static void w1_ds2780_remove_slave(struct w1_slave *sl)
 154{
 155        struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 156        int id = pdev->id;
 157
 158        platform_device_unregister(pdev);
 159        ida_simple_remove(&bat_ida, id);
 160        sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
 161}
 162
 163static struct w1_family_ops w1_ds2780_fops = {
 164        .add_slave    = w1_ds2780_add_slave,
 165        .remove_slave = w1_ds2780_remove_slave,
 166};
 167
 168static struct w1_family w1_ds2780_family = {
 169        .fid = W1_FAMILY_DS2780,
 170        .fops = &w1_ds2780_fops,
 171};
 172
 173static int __init w1_ds2780_init(void)
 174{
 175        ida_init(&bat_ida);
 176        return w1_register_family(&w1_ds2780_family);
 177}
 178
 179static void __exit w1_ds2780_exit(void)
 180{
 181        w1_unregister_family(&w1_ds2780_family);
 182        ida_destroy(&bat_ida);
 183}
 184
 185module_init(w1_ds2780_init);
 186module_exit(w1_ds2780_exit);
 187
 188MODULE_LICENSE("GPL");
 189MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
 190MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
 191