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 #include <linux/idr.h> 21 22 #include "../w1.h" 23 #include "../w1_int.h" 24 #include "../w1_family.h" 25 #include "w1_ds2781.h" 26 27 static 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 52 int 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->mutex); 62 63 ret = w1_ds2781_do_io(dev, buf, addr, count, io); 64 65 mutex_unlock(&sl->master->mutex); 66 67 return ret; 68 } 69 EXPORT_SYMBOL(w1_ds2781_io); 70 71 int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr, size_t count, 72 int io) 73 { 74 int ret; 75 76 if (!dev) 77 return -ENODEV; 78 79 ret = w1_ds2781_do_io(dev, buf, addr, count, io); 80 81 return ret; 82 } 83 EXPORT_SYMBOL(w1_ds2781_io_nolock); 84 85 int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd) 86 { 87 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 88 89 if (!dev) 90 return -EINVAL; 91 92 mutex_lock(&sl->master->mutex); 93 94 if (w1_reset_select_slave(sl) == 0) { 95 w1_write_8(sl->master, cmd); 96 w1_write_8(sl->master, addr); 97 } 98 99 mutex_unlock(&sl->master->mutex); 100 return 0; 101 } 102 EXPORT_SYMBOL(w1_ds2781_eeprom_cmd); 103 104 static ssize_t w1_ds2781_read_bin(struct file *filp, 105 struct kobject *kobj, 106 struct bin_attribute *bin_attr, 107 char *buf, loff_t off, size_t count) 108 { 109 struct device *dev = container_of(kobj, struct device, kobj); 110 return w1_ds2781_io(dev, buf, off, count, 0); 111 } 112 113 static struct bin_attribute w1_ds2781_bin_attr = { 114 .attr = { 115 .name = "w1_slave", 116 .mode = S_IRUGO, 117 }, 118 .size = DS2781_DATA_SIZE, 119 .read = w1_ds2781_read_bin, 120 }; 121 122 static DEFINE_IDA(bat_ida); 123 124 static int w1_ds2781_add_slave(struct w1_slave *sl) 125 { 126 int ret; 127 int id; 128 struct platform_device *pdev; 129 130 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL); 131 if (id < 0) { 132 ret = id; 133 goto noid; 134 } 135 136 pdev = platform_device_alloc("ds2781-battery", id); 137 if (!pdev) { 138 ret = -ENOMEM; 139 goto pdev_alloc_failed; 140 } 141 pdev->dev.parent = &sl->dev; 142 143 ret = platform_device_add(pdev); 144 if (ret) 145 goto pdev_add_failed; 146 147 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr); 148 if (ret) 149 goto bin_attr_failed; 150 151 dev_set_drvdata(&sl->dev, pdev); 152 153 return 0; 154 155 bin_attr_failed: 156 pdev_add_failed: 157 platform_device_unregister(pdev); 158 pdev_alloc_failed: 159 ida_simple_remove(&bat_ida, id); 160 noid: 161 return ret; 162 } 163 164 static void w1_ds2781_remove_slave(struct w1_slave *sl) 165 { 166 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 167 int id = pdev->id; 168 169 platform_device_unregister(pdev); 170 ida_simple_remove(&bat_ida, id); 171 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr); 172 } 173 174 static struct w1_family_ops w1_ds2781_fops = { 175 .add_slave = w1_ds2781_add_slave, 176 .remove_slave = w1_ds2781_remove_slave, 177 }; 178 179 static struct w1_family w1_ds2781_family = { 180 .fid = W1_FAMILY_DS2781, 181 .fops = &w1_ds2781_fops, 182 }; 183 184 static int __init w1_ds2781_init(void) 185 { 186 ida_init(&bat_ida); 187 return w1_register_family(&w1_ds2781_family); 188 } 189 190 static void __exit w1_ds2781_exit(void) 191 { 192 w1_unregister_family(&w1_ds2781_family); 193 ida_destroy(&bat_ida); 194 } 195 196 module_init(w1_ds2781_init); 197 module_exit(w1_ds2781_exit); 198 199 MODULE_LICENSE("GPL"); 200 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>"); 201 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC"); 202