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->mutex); 64 65 ret = w1_ds2780_do_io(dev, buf, addr, count, io); 66 67 mutex_unlock(&sl->master->mutex); 68 69 return ret; 70 } 71 EXPORT_SYMBOL(w1_ds2780_io); 72 73 int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count, 74 int io) 75 { 76 int ret; 77 78 if (!dev) 79 return -ENODEV; 80 81 ret = w1_ds2780_do_io(dev, buf, addr, count, io); 82 83 return ret; 84 } 85 EXPORT_SYMBOL(w1_ds2780_io_nolock); 86 87 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd) 88 { 89 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 90 91 if (!dev) 92 return -EINVAL; 93 94 mutex_lock(&sl->master->mutex); 95 96 if (w1_reset_select_slave(sl) == 0) { 97 w1_write_8(sl->master, cmd); 98 w1_write_8(sl->master, addr); 99 } 100 101 mutex_unlock(&sl->master->mutex); 102 return 0; 103 } 104 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); 105 106 static ssize_t w1_ds2780_read_bin(struct file *filp, 107 struct kobject *kobj, 108 struct bin_attribute *bin_attr, 109 char *buf, loff_t off, size_t count) 110 { 111 struct device *dev = container_of(kobj, struct device, kobj); 112 return w1_ds2780_io(dev, buf, off, count, 0); 113 } 114 115 static struct bin_attribute w1_ds2780_bin_attr = { 116 .attr = { 117 .name = "w1_slave", 118 .mode = S_IRUGO, 119 }, 120 .size = DS2780_DATA_SIZE, 121 .read = w1_ds2780_read_bin, 122 }; 123 124 static DEFINE_IDA(bat_ida); 125 126 static int w1_ds2780_add_slave(struct w1_slave *sl) 127 { 128 int ret; 129 int id; 130 struct platform_device *pdev; 131 132 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL); 133 if (id < 0) { 134 ret = id; 135 goto noid; 136 } 137 138 pdev = platform_device_alloc("ds2780-battery", id); 139 if (!pdev) { 140 ret = -ENOMEM; 141 goto pdev_alloc_failed; 142 } 143 pdev->dev.parent = &sl->dev; 144 145 ret = platform_device_add(pdev); 146 if (ret) 147 goto pdev_add_failed; 148 149 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr); 150 if (ret) 151 goto bin_attr_failed; 152 153 dev_set_drvdata(&sl->dev, pdev); 154 155 return 0; 156 157 bin_attr_failed: 158 pdev_add_failed: 159 platform_device_unregister(pdev); 160 pdev_alloc_failed: 161 ida_simple_remove(&bat_ida, id); 162 noid: 163 return ret; 164 } 165 166 static void w1_ds2780_remove_slave(struct w1_slave *sl) 167 { 168 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 169 int id = pdev->id; 170 171 platform_device_unregister(pdev); 172 ida_simple_remove(&bat_ida, id); 173 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr); 174 } 175 176 static struct w1_family_ops w1_ds2780_fops = { 177 .add_slave = w1_ds2780_add_slave, 178 .remove_slave = w1_ds2780_remove_slave, 179 }; 180 181 static struct w1_family w1_ds2780_family = { 182 .fid = W1_FAMILY_DS2780, 183 .fops = &w1_ds2780_fops, 184 }; 185 186 static int __init w1_ds2780_init(void) 187 { 188 ida_init(&bat_ida); 189 return w1_register_family(&w1_ds2780_family); 190 } 191 192 static void __exit w1_ds2780_exit(void) 193 { 194 w1_unregister_family(&w1_ds2780_family); 195 ida_destroy(&bat_ida); 196 } 197 198 module_init(w1_ds2780_init); 199 module_exit(w1_ds2780_exit); 200 201 MODULE_LICENSE("GPL"); 202 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>"); 203 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC"); 204