drivers/w1/slaves/w1_ds2780.c

   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 <linux/w1.h>
  25
  26 #include "w1_ds2780.h"
  27
  28 #define W1_FAMILY_DS2780        0x32
  29
  30 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
  31                         size_t count, int io)
  32 {
  33         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  34
  35         if (addr > DS2780_DATA_SIZE || addr < 0)
  36                 return 0;
  37
  38         count = min_t(int, count, DS2780_DATA_SIZE - addr);
  39
  40         if (w1_reset_select_slave(sl) == 0) {
  41                 if (io) {
  42                         w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
  43                         w1_write_8(sl->master, addr);
  44                         w1_write_block(sl->master, buf, count);
  45                 } else {
  46                         w1_write_8(sl->master, W1_DS2780_READ_DATA);
  47                         w1_write_8(sl->master, addr);
  48                         count = w1_read_block(sl->master, buf, count);
  49                 }
  50         }
  51
  52         return count;
  53 }
  54
  55 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  56                         int io)
  57 {
  58         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  59         int ret;
  60
  61         if (!dev)
  62                 return -ENODEV;
  63
  64         mutex_lock(&sl->master->bus_mutex);
  65
  66         ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  67
  68         mutex_unlock(&sl->master->bus_mutex);
  69
  70         return ret;
  71 }
  72 EXPORT_SYMBOL(w1_ds2780_io);
  73
  74 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
  75 {
  76         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  77
  78         if (!dev)
  79                 return -EINVAL;
  80
  81         mutex_lock(&sl->master->bus_mutex);
  82
  83         if (w1_reset_select_slave(sl) == 0) {
  84                 w1_write_8(sl->master, cmd);
  85                 w1_write_8(sl->master, addr);
  86         }
  87
  88         mutex_unlock(&sl->master->bus_mutex);
  89         return 0;
  90 }
  91 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
  92
  93 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
  94                              struct bin_attribute *bin_attr, char *buf,
  95                              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
 101 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
 102
 103 static struct bin_attribute *w1_ds2780_bin_attrs[] = {
 104         &bin_attr_w1_slave,
 105         NULL,
 106 };
 107
 108 static const struct attribute_group w1_ds2780_group = {
 109         .bin_attrs = w1_ds2780_bin_attrs,
 110 };
 111
 112 static const struct attribute_group *w1_ds2780_groups[] = {
 113         &w1_ds2780_group,
 114         NULL,
 115 };
 116
 117 static int w1_ds2780_add_slave(struct w1_slave *sl)
 118 {
 119         int ret;
 120         struct platform_device *pdev;
 121
 122         pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
 123         if (!pdev)
 124                 return -ENOMEM;
 125         pdev->dev.parent = &sl->dev;
 126
 127         ret = platform_device_add(pdev);
 128         if (ret)
 129                 goto pdev_add_failed;
 130
 131         dev_set_drvdata(&sl->dev, pdev);
 132
 133         return 0;
 134
 135 pdev_add_failed:
 136         platform_device_put(pdev);
 137
 138         return ret;
 139 }
 140
 141 static void w1_ds2780_remove_slave(struct w1_slave *sl)
 142 {
 143         struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 144
 145         platform_device_unregister(pdev);
 146 }
 147
 148 static struct w1_family_ops w1_ds2780_fops = {
 149         .add_slave    = w1_ds2780_add_slave,
 150         .remove_slave = w1_ds2780_remove_slave,
 151         .groups       = w1_ds2780_groups,
 152 };
 153
 154 static struct w1_family w1_ds2780_family = {
 155         .fid = W1_FAMILY_DS2780,
 156         .fops = &w1_ds2780_fops,
 157 };
 158 module_w1_family(w1_ds2780_family);
 159
 160 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
 161 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
 162 MODULE_LICENSE("GPL");
 163 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));