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 <linux/w1.h>
  22
  23 #include "w1_ds2760.h"
  24
  25 #define W1_FAMILY_DS2760        0x30
  26
  27 static 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
  57 out:
  58         mutex_unlock(&sl->master->bus_mutex);
  59
  60         return count;
  61 }
  62
  63 int 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 }
  67 EXPORT_SYMBOL(w1_ds2760_read);
  68
  69 int 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 }
  73 EXPORT_SYMBOL(w1_ds2760_write);
  74
  75 static 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
  93 int w1_ds2760_store_eeprom(struct device *dev, int addr)
  94 {
  95         return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
  96 }
  97 EXPORT_SYMBOL(w1_ds2760_store_eeprom);
  98
  99 int w1_ds2760_recall_eeprom(struct device *dev, int addr)
 100 {
 101         return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
 102 }
 103 EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
 104
 105 static 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
 113 static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
 114
 115 static struct bin_attribute *w1_ds2760_bin_attrs[] = {
 116         &bin_attr_w1_slave,
 117         NULL,
 118 };
 119
 120 static const struct attribute_group w1_ds2760_group = {
 121         .bin_attrs = w1_ds2760_bin_attrs,
 122 };
 123
 124 static const struct attribute_group *w1_ds2760_groups[] = {
 125         &w1_ds2760_group,
 126         NULL,
 127 };
 128
 129 static 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
 147 pdev_add_failed:
 148         platform_device_put(pdev);
 149
 150         return ret;
 151 }
 152
 153 static 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
 160 static 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
 166 static struct w1_family w1_ds2760_family = {
 167         .fid = W1_FAMILY_DS2760,
 168         .fops = &w1_ds2760_fops,
 169 };
 170 module_w1_family(w1_ds2760_family);
 171
 172 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
 173 MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
 174 MODULE_LICENSE("GPL");
 175 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));