LXR linux/drivers/w1/slaves/w1

   1/*
   2 * 1-Wire implementation for the ds2781 chip
   3 *
   4 * Author: Renata Sayakhova <renata@oktetlabs.ru>
   5 *
   6 * Based on w1-ds2780 driver
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/device.h>
  17#include <linux/types.h>
  18#include <linux/platform_device.h>
  19#include <linux/mutex.h>
  20
  21#include <linux/w1.h>
  22
  23#include "w1_ds2781.h"
  24
  25#define W1_FAMILY_DS2781        0x3D
  26
  27static int w1_ds2781_do_io(struct device *dev, char *buf, int addr,
  28                        size_t count, int io)
  29{
  30        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  31
  32        if (addr > DS2781_DATA_SIZE || addr < 0)
  33                return 0;
  34
  35        count = min_t(int, count, DS2781_DATA_SIZE - addr);
  36
  37        if (w1_reset_select_slave(sl) == 0) {
  38                if (io) {
  39                        w1_write_8(sl->master, W1_DS2781_WRITE_DATA);
  40                        w1_write_8(sl->master, addr);
  41                        w1_write_block(sl->master, buf, count);
  42                } else {
  43                        w1_write_8(sl->master, W1_DS2781_READ_DATA);
  44                        w1_write_8(sl->master, addr);
  45                        count = w1_read_block(sl->master, buf, count);
  46                }
  47        }
  48
  49        return count;
  50}
  51
  52int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
  53                        int io)
  54{
  55        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  56        int ret;
  57
  58        if (!dev)
  59                return -ENODEV;
  60
  61        mutex_lock(&sl->master->bus_mutex);
  62
  63        ret = w1_ds2781_do_io(dev, buf, addr, count, io);
  64
  65        mutex_unlock(&sl->master->bus_mutex);
  66
  67        return ret;
  68}
  69EXPORT_SYMBOL(w1_ds2781_io);
  70
  71int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
  72{
  73        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  74
  75        if (!dev)
  76                return -EINVAL;
  77
  78        mutex_lock(&sl->master->bus_mutex);
  79
  80        if (w1_reset_select_slave(sl) == 0) {
  81                w1_write_8(sl->master, cmd);
  82                w1_write_8(sl->master, addr);
  83        }
  84
  85        mutex_unlock(&sl->master->bus_mutex);
  86        return 0;
  87}
  88EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
  89
  90static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
  91                             struct bin_attribute *bin_attr, char *buf,
  92                             loff_t off, size_t count)
  93{
  94        struct device *dev = container_of(kobj, struct device, kobj);
  95        return w1_ds2781_io(dev, buf, off, count, 0);
  96}
  97
  98static BIN_ATTR_RO(w1_slave, DS2781_DATA_SIZE);
  99
 100static struct bin_attribute *w1_ds2781_bin_attrs[] = {
 101        &bin_attr_w1_slave,
 102        NULL,
 103};
 104
 105static const struct attribute_group w1_ds2781_group = {
 106        .bin_attrs = w1_ds2781_bin_attrs,
 107};
 108
 109static const struct attribute_group *w1_ds2781_groups[] = {
 110        &w1_ds2781_group,
 111        NULL,
 112};
 113
 114static int w1_ds2781_add_slave(struct w1_slave *sl)
 115{
 116        int ret;
 117        struct platform_device *pdev;
 118
 119        pdev = platform_device_alloc("ds2781-battery", PLATFORM_DEVID_AUTO);
 120        if (!pdev)
 121                return -ENOMEM;
 122        pdev->dev.parent = &sl->dev;
 123
 124        ret = platform_device_add(pdev);
 125        if (ret)
 126                goto pdev_add_failed;
 127
 128        dev_set_drvdata(&sl->dev, pdev);
 129
 130        return 0;
 131
 132pdev_add_failed:
 133        platform_device_put(pdev);
 134
 135        return ret;
 136}
 137
 138static void w1_ds2781_remove_slave(struct w1_slave *sl)
 139{
 140        struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 141
 142        platform_device_unregister(pdev);
 143}
 144
 145static struct w1_family_ops w1_ds2781_fops = {
 146        .add_slave    = w1_ds2781_add_slave,
 147        .remove_slave = w1_ds2781_remove_slave,
 148        .groups       = w1_ds2781_groups,
 149};
 150
 151static struct w1_family w1_ds2781_family = {
 152        .fid = W1_FAMILY_DS2781,
 153        .fops = &w1_ds2781_fops,
 154};
 155module_w1_family(w1_ds2781_family);
 156
 157MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
 158MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");
 159MODULE_LICENSE("GPL");
 160MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2781));
 161