drivers/w1/slaves/w1_ds2760.c

   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 "../w1.h"
  22 #include "../w1_int.h"
  23 #include "../w1_family.h"
  24 #include "w1_ds2760.h"
  25
  26 static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
  27                         int io)
  28 {
  29         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  30
  31         if (!dev)
  32                 return 0;
  33
  34         mutex_lock(&sl->master->bus_mutex);
  35
  36         if (addr > DS2760_DATA_SIZE || addr < 0) {
  37                 count = 0;
  38                 goto out;
  39         }
  40         if (addr + count > DS2760_DATA_SIZE)
  41                 count = DS2760_DATA_SIZE - addr;
  42
  43         if (!w1_reset_select_slave(sl)) {
  44                 if (!io) {
  45                         w1_write_8(sl->master, W1_DS2760_READ_DATA);
  46                         w1_write_8(sl->master, addr);
  47                         count = w1_read_block(sl->master, buf, count);
  48                 } else {
  49                         w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
  50                         w1_write_8(sl->master, addr);
  51                         w1_write_block(sl->master, buf, count);
  52                         /* XXX w1_write_block returns void, not n_written */
  53                 }
  54         }
  55
  56 out:
  57         mutex_unlock(&sl->master->bus_mutex);
  58
  59         return count;
  60 }
  61
  62 int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
  63 {
  64         return w1_ds2760_io(dev, buf, addr, count, 0);
  65 }
  66
  67 int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
  68 {
  69         return w1_ds2760_io(dev, buf, addr, count, 1);
  70 }
  71
  72 static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
  73 {
  74         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  75
  76         if (!dev)
  77                 return -EINVAL;
  78
  79         mutex_lock(&sl->master->bus_mutex);
  80
  81         if (w1_reset_select_slave(sl) == 0) {
  82                 w1_write_8(sl->master, cmd);
  83                 w1_write_8(sl->master, addr);
  84         }
  85
  86         mutex_unlock(&sl->master->bus_mutex);
  87         return 0;
  88 }
  89
  90 int w1_ds2760_store_eeprom(struct device *dev, int addr)
  91 {
  92         return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
  93 }
  94
  95 int w1_ds2760_recall_eeprom(struct device *dev, int addr)
  96 {
  97         return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
  98 }
  99
 100 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
 101                              struct bin_attribute *bin_attr, char *buf,
 102                              loff_t off, size_t count)
 103 {
 104         struct device *dev = container_of(kobj, struct device, kobj);
 105         return w1_ds2760_read(dev, buf, off, count);
 106 }
 107
 108 static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
 109
 110 static struct bin_attribute *w1_ds2760_bin_attrs[] = {
 111         &bin_attr_w1_slave,
 112         NULL,
 113 };
 114
 115 static const struct attribute_group w1_ds2760_group = {
 116         .bin_attrs = w1_ds2760_bin_attrs,
 117 };
 118
 119 static const struct attribute_group *w1_ds2760_groups[] = {
 120         &w1_ds2760_group,
 121         NULL,
 122 };
 123
 124 static DEFINE_IDA(bat_ida);
 125
 126 static int w1_ds2760_add_slave(struct w1_slave *sl)
 127 {
 128         int ret;
 129         int id;
 130         struct platform_device *pdev;
 131
 132         id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
 133         if (id < 0) {
 134                 ret = id;
 135                 goto noid;
 136         }
 137
 138         pdev = platform_device_alloc("ds2760-battery", id);
 139         if (!pdev) {
 140                 ret = -ENOMEM;
 141                 goto pdev_alloc_failed;
 142         }
 143         pdev->dev.parent = &sl->dev;
 144
 145         ret = platform_device_add(pdev);
 146         if (ret)
 147                 goto pdev_add_failed;
 148
 149         dev_set_drvdata(&sl->dev, pdev);
 150
 151         goto success;
 152
 153 pdev_add_failed:
 154         platform_device_put(pdev);
 155 pdev_alloc_failed:
 156         ida_simple_remove(&bat_ida, id);
 157 noid:
 158 success:
 159         return ret;
 160 }
 161
 162 static void w1_ds2760_remove_slave(struct w1_slave *sl)
 163 {
 164         struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 165         int id = pdev->id;
 166
 167         platform_device_unregister(pdev);
 168         ida_simple_remove(&bat_ida, id);
 169 }
 170
 171 static struct w1_family_ops w1_ds2760_fops = {
 172         .add_slave    = w1_ds2760_add_slave,
 173         .remove_slave = w1_ds2760_remove_slave,
 174         .groups       = w1_ds2760_groups,
 175 };
 176
 177 static struct w1_family w1_ds2760_family = {
 178         .fid = W1_FAMILY_DS2760,
 179         .fops = &w1_ds2760_fops,
 180 };
 181
 182 static int __init w1_ds2760_init(void)
 183 {
 184         pr_info("1-Wire driver for the DS2760 battery monitor chip - (c) 2004-2005, Szabolcs Gyurko\n");
 185         ida_init(&bat_ida);
 186         return w1_register_family(&w1_ds2760_family);
 187 }
 188
 189 static void __exit w1_ds2760_exit(void)
 190 {
 191         w1_unregister_family(&w1_ds2760_family);
 192         ida_destroy(&bat_ida);
 193 }
 194
 195 EXPORT_SYMBOL(w1_ds2760_read);
 196 EXPORT_SYMBOL(w1_ds2760_write);
 197 EXPORT_SYMBOL(w1_ds2760_store_eeprom);
 198 EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
 199
 200 module_init(w1_ds2760_init);
 201 module_exit(w1_ds2760_exit);
 202
 203 MODULE_LICENSE("GPL");
 204 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
 205 MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
 206 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));