LXR linux/drivers/w1/slaves/w1

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * 1-Wire implementation for the ds2780 chip
   4 *
   5 * Copyright (C) 2010 Indesign, LLC
   6 *
   7 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
   8 *
   9 * Based on w1-ds2760 driver
  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
  20#include <linux/w1.h>
  21
  22#include "w1_ds2780.h"
  23
  24#define W1_FAMILY_DS2780        0x32
  25
  26static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
  27                        size_t count, int io)
  28{
  29        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  30
  31        if (addr > DS2780_DATA_SIZE || addr < 0)
  32                return 0;
  33
  34        count = min_t(int, count, DS2780_DATA_SIZE - addr);
  35
  36        if (w1_reset_select_slave(sl) == 0) {
  37                if (io) {
  38                        w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
  39                        w1_write_8(sl->master, addr);
  40                        w1_write_block(sl->master, buf, count);
  41                } else {
  42                        w1_write_8(sl->master, W1_DS2780_READ_DATA);
  43                        w1_write_8(sl->master, addr);
  44                        count = w1_read_block(sl->master, buf, count);
  45                }
  46        }
  47
  48        return count;
  49}
  50
  51int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  52                        int io)
  53{
  54        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  55        int ret;
  56
  57        if (!dev)
  58                return -ENODEV;
  59
  60        mutex_lock(&sl->master->bus_mutex);
  61
  62        ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  63
  64        mutex_unlock(&sl->master->bus_mutex);
  65
  66        return ret;
  67}
  68EXPORT_SYMBOL(w1_ds2780_io);
  69
  70int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
  71{
  72        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  73
  74        if (!dev)
  75                return -EINVAL;
  76
  77        mutex_lock(&sl->master->bus_mutex);
  78
  79        if (w1_reset_select_slave(sl) == 0) {
  80                w1_write_8(sl->master, cmd);
  81                w1_write_8(sl->master, addr);
  82        }
  83
  84        mutex_unlock(&sl->master->bus_mutex);
  85        return 0;
  86}
  87EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
  88
  89static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
  90                             struct bin_attribute *bin_attr, char *buf,
  91                             loff_t off, size_t count)
  92{
  93        struct device *dev = kobj_to_dev(kobj);
  94        return w1_ds2780_io(dev, buf, off, count, 0);
  95}
  96
  97static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
  98
  99static struct bin_attribute *w1_ds2780_bin_attrs[] = {
 100        &bin_attr_w1_slave,
 101        NULL,
 102};
 103
 104static const struct attribute_group w1_ds2780_group = {
 105        .bin_attrs = w1_ds2780_bin_attrs,
 106};
 107
 108static const struct attribute_group *w1_ds2780_groups[] = {
 109        &w1_ds2780_group,
 110        NULL,
 111};
 112
 113static int w1_ds2780_add_slave(struct w1_slave *sl)
 114{
 115        int ret;
 116        struct platform_device *pdev;
 117
 118        pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
 119        if (!pdev)
 120                return -ENOMEM;
 121        pdev->dev.parent = &sl->dev;
 122
 123        ret = platform_device_add(pdev);
 124        if (ret)
 125                goto pdev_add_failed;
 126
 127        dev_set_drvdata(&sl->dev, pdev);
 128
 129        return 0;
 130
 131pdev_add_failed:
 132        platform_device_put(pdev);
 133
 134        return ret;
 135}
 136
 137static void w1_ds2780_remove_slave(struct w1_slave *sl)
 138{
 139        struct platform_device *pdev = dev_get_drvdata(&sl->dev);
 140
 141        platform_device_unregister(pdev);
 142}
 143
 144static const struct w1_family_ops w1_ds2780_fops = {
 145        .add_slave    = w1_ds2780_add_slave,
 146        .remove_slave = w1_ds2780_remove_slave,
 147        .groups       = w1_ds2780_groups,
 148};
 149
 150static struct w1_family w1_ds2780_family = {
 151        .fid = W1_FAMILY_DS2780,
 152        .fops = &w1_ds2780_fops,
 153};
 154module_w1_family(w1_ds2780_family);
 155
 156MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
 157MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
 158MODULE_LICENSE("GPL");
 159MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));
 160