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 "../w1.h" 25 #include "../w1_int.h" 26 #include "../w1_family.h" 27 #include "w1_ds2780.h" 28 29 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr, 30 size_t count, int io) 31 { 32 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 33 34 if (addr > DS2780_DATA_SIZE || addr < 0) 35 return 0; 36 37 count = min_t(int, count, DS2780_DATA_SIZE - addr); 38 39 if (w1_reset_select_slave(sl) == 0) { 40 if (io) { 41 w1_write_8(sl->master, W1_DS2780_WRITE_DATA); 42 w1_write_8(sl->master, addr); 43 w1_write_block(sl->master, buf, count); 44 } else { 45 w1_write_8(sl->master, W1_DS2780_READ_DATA); 46 w1_write_8(sl->master, addr); 47 count = w1_read_block(sl->master, buf, count); 48 } 49 } 50 51 return count; 52 } 53 54 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count, 55 int io) 56 { 57 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 58 int ret; 59 60 if (!dev) 61 return -ENODEV; 62 63 mutex_lock(&sl->master->bus_mutex); 64 65 ret = w1_ds2780_do_io(dev, buf, addr, count, io); 66 67 mutex_unlock(&sl->master->bus_mutex); 68 69 return ret; 70 } 71 EXPORT_SYMBOL(w1_ds2780_io); 72 73 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd) 74 { 75 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 76 77 if (!dev) 78 return -EINVAL; 79 80 mutex_lock(&sl->master->bus_mutex); 81 82 if (w1_reset_select_slave(sl) == 0) { 83 w1_write_8(sl->master, cmd); 84 w1_write_8(sl->master, addr); 85 } 86 87 mutex_unlock(&sl->master->bus_mutex); 88 return 0; 89 } 90 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); 91 92 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj, 93 struct bin_attribute *bin_attr, char *buf, 94 loff_t off, size_t count) 95 { 96 struct device *dev = container_of(kobj, struct device, kobj); 97 return w1_ds2780_io(dev, buf, off, count, 0); 98 } 99 100 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE); 101 102 static struct bin_attribute *w1_ds2780_bin_attrs[] = { 103 &bin_attr_w1_slave, 104 NULL, 105 }; 106 107 static const struct attribute_group w1_ds2780_group = { 108 .bin_attrs = w1_ds2780_bin_attrs, 109 }; 110 111 static const struct attribute_group *w1_ds2780_groups[] = { 112 &w1_ds2780_group, 113 NULL, 114 }; 115 116 static DEFINE_IDA(bat_ida); 117 118 static int w1_ds2780_add_slave(struct w1_slave *sl) 119 { 120 int ret; 121 int id; 122 struct platform_device *pdev; 123 124 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL); 125 if (id < 0) { 126 ret = id; 127 goto noid; 128 } 129 130 pdev = platform_device_alloc("ds2780-battery", id); 131 if (!pdev) { 132 ret = -ENOMEM; 133 goto pdev_alloc_failed; 134 } 135 pdev->dev.parent = &sl->dev; 136 137 ret = platform_device_add(pdev); 138 if (ret) 139 goto pdev_add_failed; 140 141 dev_set_drvdata(&sl->dev, pdev); 142 143 return 0; 144 145 pdev_add_failed: 146 platform_device_put(pdev); 147 pdev_alloc_failed: 148 ida_simple_remove(&bat_ida, id); 149 noid: 150 return ret; 151 } 152 153 static void w1_ds2780_remove_slave(struct w1_slave *sl) 154 { 155 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 156 int id = pdev->id; 157 158 platform_device_unregister(pdev); 159 ida_simple_remove(&bat_ida, id); 160 } 161 162 static struct w1_family_ops w1_ds2780_fops = { 163 .add_slave = w1_ds2780_add_slave, 164 .remove_slave = w1_ds2780_remove_slave, 165 .groups = w1_ds2780_groups, 166 }; 167 168 static struct w1_family w1_ds2780_family = { 169 .fid = W1_FAMILY_DS2780, 170 .fops = &w1_ds2780_fops, 171 }; 172 173 static int __init w1_ds2780_init(void) 174 { 175 ida_init(&bat_ida); 176 return w1_register_family(&w1_ds2780_family); 177 } 178 179 static void __exit w1_ds2780_exit(void) 180 { 181 w1_unregister_family(&w1_ds2780_family); 182 ida_destroy(&bat_ida); 183 } 184 185 module_init(w1_ds2780_init); 186 module_exit(w1_ds2780_exit); 187 188 MODULE_LICENSE("GPL"); 189 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>"); 190 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC"); 191 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780)); 192