1/* 2 * 1-Wire implementation for the ds2760 chip 3 * 4 * Copyright �� 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> 5 * 6 * Use consistent with the GNU GPL is permitted, 7 * provided that this copyright notice is 8 * preserved in its entirety in all copies and derived works. 9 * 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#include <linux/gfp.h> 20 21#include "../w1.h" 22#include "../w1_int.h" 23#include "../w1_family.h" 24#include "w1_ds2760.h" 25 26static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count, 27 int io) 28{ 29 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 30 31 if (!dev) 32 return 0; 33 34 mutex_lock(&sl->master->mutex); 35 36 if (addr > DS2760_DATA_SIZE || addr < 0) { 37 count = 0; 38 goto out; 39 } 40 if (addr + count > DS2760_DATA_SIZE) 41 count = DS2760_DATA_SIZE - addr; 42 43 if (!w1_reset_select_slave(sl)) { 44 if (!io) { 45 w1_write_8(sl->master, W1_DS2760_READ_DATA); 46 w1_write_8(sl->master, addr); 47 count = w1_read_block(sl->master, buf, count); 48 } else { 49 w1_write_8(sl->master, W1_DS2760_WRITE_DATA); 50 w1_write_8(sl->master, addr); 51 w1_write_block(sl->master, buf, count); 52 } 53 } 54 55out: 56 mutex_unlock(&sl->master->mutex); 57 58 return count; 59} 60 61int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count) 62{ 63 return w1_ds2760_io(dev, buf, addr, count, 0); 64} 65 66int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count) 67{ 68 return w1_ds2760_io(dev, buf, addr, count, 1); 69} 70 71static int w1_ds2760_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->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->mutex); 86 return 0; 87} 88 89int w1_ds2760_store_eeprom(struct device *dev, int addr) 90{ 91 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA); 92} 93 94int w1_ds2760_recall_eeprom(struct device *dev, int addr) 95{ 96 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA); 97} 98 99static ssize_t w1_ds2760_read_bin(struct file *filp, struct kobject *kobj, 100 struct bin_attribute *bin_attr, 101 char *buf, loff_t off, size_t count) 102{ 103 struct device *dev = container_of(kobj, struct device, kobj); 104 return w1_ds2760_read(dev, buf, off, count); 105} 106 107static struct bin_attribute w1_ds2760_bin_attr = { 108 .attr = { 109 .name = "w1_slave", 110 .mode = S_IRUGO, 111 }, 112 .size = DS2760_DATA_SIZE, 113 .read = w1_ds2760_read_bin, 114}; 115 116static DEFINE_IDR(bat_idr); 117static DEFINE_MUTEX(bat_idr_lock); 118 119static int new_bat_id(void) 120{ 121 int ret; 122 123 while (1) { 124 int id; 125 126 ret = idr_pre_get(&bat_idr, GFP_KERNEL); 127 if (ret == 0) 128 return -ENOMEM; 129 130 mutex_lock(&bat_idr_lock); 131 ret = idr_get_new(&bat_idr, NULL, &id); 132 mutex_unlock(&bat_idr_lock); 133 134 if (ret == 0) { 135 ret = id & MAX_ID_MASK; 136 break; 137 } else if (ret == -EAGAIN) { 138 continue; 139 } else { 140 break; 141 } 142 } 143 144 return ret; 145} 146 147static void release_bat_id(int id) 148{ 149 mutex_lock(&bat_idr_lock); 150 idr_remove(&bat_idr, id); 151 mutex_unlock(&bat_idr_lock); 152} 153 154static int w1_ds2760_add_slave(struct w1_slave *sl) 155{ 156 int ret; 157 int id; 158 struct platform_device *pdev; 159 160 id = new_bat_id(); 161 if (id < 0) { 162 ret = id; 163 goto noid; 164 } 165 166 pdev = platform_device_alloc("ds2760-battery", id); 167 if (!pdev) { 168 ret = -ENOMEM; 169 goto pdev_alloc_failed; 170 } 171 pdev->dev.parent = &sl->dev; 172 173 ret = platform_device_add(pdev); 174 if (ret) 175 goto pdev_add_failed; 176 177 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr); 178 if (ret) 179 goto bin_attr_failed; 180 181 dev_set_drvdata(&sl->dev, pdev); 182 183 goto success; 184 185bin_attr_failed: 186pdev_add_failed: 187 platform_device_unregister(pdev); 188pdev_alloc_failed: 189 release_bat_id(id); 190noid: 191success: 192 return ret; 193} 194 195static void w1_ds2760_remove_slave(struct w1_slave *sl) 196{ 197 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 198 int id = pdev->id; 199 200 platform_device_unregister(pdev); 201 release_bat_id(id); 202 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr); 203} 204 205static struct w1_family_ops w1_ds2760_fops = { 206 .add_slave = w1_ds2760_add_slave, 207 .remove_slave = w1_ds2760_remove_slave, 208}; 209 210static struct w1_family w1_ds2760_family = { 211 .fid = W1_FAMILY_DS2760, 212 .fops = &w1_ds2760_fops, 213}; 214 215static int __init w1_ds2760_init(void) 216{ 217 printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor " 218 " chip - (c) 2004-2005, Szabolcs Gyurko\n"); 219 idr_init(&bat_idr); 220 return w1_register_family(&w1_ds2760_family); 221} 222 223static void __exit w1_ds2760_exit(void) 224{ 225 w1_unregister_family(&w1_ds2760_family); 226 idr_destroy(&bat_idr); 227} 228 229EXPORT_SYMBOL(w1_ds2760_read); 230EXPORT_SYMBOL(w1_ds2760_write); 231EXPORT_SYMBOL(w1_ds2760_store_eeprom); 232EXPORT_SYMBOL(w1_ds2760_recall_eeprom); 233 234module_init(w1_ds2760_init); 235module_exit(w1_ds2760_exit); 236 237MODULE_LICENSE("GPL"); 238MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>"); 239MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip"); 240