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->bus_mutex); 62 63 ret = w1_ds2781_do_io(dev, buf, addr, count, io); 64 65 mutex_unlock(&sl->master->bus_mutex); 66 67 return ret; 68 } 69 EXPORT_SYMBOL(w1_ds2781_io); 70 71 int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd) 72 { 73 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 74 75 if (!dev) 76 return -EINVAL; 77 78 mutex_lock(&sl->master->bus_mutex); 79 80 if (w1_reset_select_slave(sl) == 0) { 81 w1_write_8(sl->master, cmd); 82 w1_write_8(sl->master, addr); 83 } 84 85 mutex_unlock(&sl->master->bus_mutex); 86 return 0; 87 } 88 EXPORT_SYMBOL(w1_ds2781_eeprom_cmd); 89 90 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj, 91 struct bin_attribute *bin_attr, char *buf, 92 loff_t off, size_t count) 93 { 94 struct device *dev = container_of(kobj, struct device, kobj); 95 return w1_ds2781_io(dev, buf, off, count, 0); 96 } 97 98 static BIN_ATTR_RO(w1_slave, DS2781_DATA_SIZE); 99 100 static struct bin_attribute *w1_ds2781_bin_attrs[] = { 101 &bin_attr_w1_slave, 102 NULL, 103 }; 104 105 static const struct attribute_group w1_ds2781_group = { 106 .bin_attrs = w1_ds2781_bin_attrs, 107 }; 108 109 static const struct attribute_group *w1_ds2781_groups[] = { 110 &w1_ds2781_group, 111 NULL, 112 }; 113 114 static DEFINE_IDA(bat_ida); 115 116 static int w1_ds2781_add_slave(struct w1_slave *sl) 117 { 118 int ret; 119 int id; 120 struct platform_device *pdev; 121 122 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL); 123 if (id < 0) { 124 ret = id; 125 goto noid; 126 } 127 128 pdev = platform_device_alloc("ds2781-battery", id); 129 if (!pdev) { 130 ret = -ENOMEM; 131 goto pdev_alloc_failed; 132 } 133 pdev->dev.parent = &sl->dev; 134 135 ret = platform_device_add(pdev); 136 if (ret) 137 goto pdev_add_failed; 138 139 dev_set_drvdata(&sl->dev, pdev); 140 141 return 0; 142 143 pdev_add_failed: 144 platform_device_put(pdev); 145 pdev_alloc_failed: 146 ida_simple_remove(&bat_ida, id); 147 noid: 148 return ret; 149 } 150 151 static void w1_ds2781_remove_slave(struct w1_slave *sl) 152 { 153 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 154 int id = pdev->id; 155 156 platform_device_unregister(pdev); 157 ida_simple_remove(&bat_ida, id); 158 } 159 160 static struct w1_family_ops w1_ds2781_fops = { 161 .add_slave = w1_ds2781_add_slave, 162 .remove_slave = w1_ds2781_remove_slave, 163 .groups = w1_ds2781_groups, 164 }; 165 166 static struct w1_family w1_ds2781_family = { 167 .fid = W1_FAMILY_DS2781, 168 .fops = &w1_ds2781_fops, 169 }; 170 171 static int __init w1_ds2781_init(void) 172 { 173 ida_init(&bat_ida); 174 return w1_register_family(&w1_ds2781_family); 175 } 176 177 static void __exit w1_ds2781_exit(void) 178 { 179 w1_unregister_family(&w1_ds2781_family); 180 ida_destroy(&bat_ida); 181 } 182 183 module_init(w1_ds2781_init); 184 module_exit(w1_ds2781_exit); 185 186 MODULE_LICENSE("GPL"); 187 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>"); 188 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC"); 189 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2781)); 190