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->bus_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 /* XXX w1_write_block returns void, not n_written */ 53 } 54 } 55 56out: 57 mutex_unlock(&sl->master->bus_mutex); 58 59 return count; 60} 61 62int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count) 63{ 64 return w1_ds2760_io(dev, buf, addr, count, 0); 65} 66 67int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count) 68{ 69 return w1_ds2760_io(dev, buf, addr, count, 1); 70} 71 72static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd) 73{ 74 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 75 76 if (!dev) 77 return -EINVAL; 78 79 mutex_lock(&sl->master->bus_mutex); 80 81 if (w1_reset_select_slave(sl) == 0) { 82 w1_write_8(sl->master, cmd); 83 w1_write_8(sl->master, addr); 84 } 85 86 mutex_unlock(&sl->master->bus_mutex); 87 return 0; 88} 89 90int w1_ds2760_store_eeprom(struct device *dev, int addr) 91{ 92 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA); 93} 94 95int w1_ds2760_recall_eeprom(struct device *dev, int addr) 96{ 97 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA); 98} 99 100static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj, 101 struct bin_attribute *bin_attr, char *buf, 102 loff_t off, size_t count) 103{ 104 struct device *dev = container_of(kobj, struct device, kobj); 105 return w1_ds2760_read(dev, buf, off, count); 106} 107 108static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE); 109 110static struct bin_attribute *w1_ds2760_bin_attrs[] = { 111 &bin_attr_w1_slave, 112 NULL, 113}; 114 115static const struct attribute_group w1_ds2760_group = { 116 .bin_attrs = w1_ds2760_bin_attrs, 117}; 118 119static const struct attribute_group *w1_ds2760_groups[] = { 120 &w1_ds2760_group, 121 NULL, 122}; 123 124static DEFINE_IDA(bat_ida); 125 126static int w1_ds2760_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("ds2760-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 dev_set_drvdata(&sl->dev, pdev); 150 151 goto success; 152 153pdev_add_failed: 154 platform_device_put(pdev); 155pdev_alloc_failed: 156 ida_simple_remove(&bat_ida, id); 157noid: 158success: 159 return ret; 160} 161 162static void w1_ds2760_remove_slave(struct w1_slave *sl) 163{ 164 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 165 int id = pdev->id; 166 167 platform_device_unregister(pdev); 168 ida_simple_remove(&bat_ida, id); 169} 170 171static struct w1_family_ops w1_ds2760_fops = { 172 .add_slave = w1_ds2760_add_slave, 173 .remove_slave = w1_ds2760_remove_slave, 174 .groups = w1_ds2760_groups, 175}; 176 177static struct w1_family w1_ds2760_family = { 178 .fid = W1_FAMILY_DS2760, 179 .fops = &w1_ds2760_fops, 180}; 181 182static int __init w1_ds2760_init(void) 183{ 184 pr_info("1-Wire driver for the DS2760 battery monitor chip - (c) 2004-2005, Szabolcs Gyurko\n"); 185 ida_init(&bat_ida); 186 return w1_register_family(&w1_ds2760_family); 187} 188 189static void __exit w1_ds2760_exit(void) 190{ 191 w1_unregister_family(&w1_ds2760_family); 192 ida_destroy(&bat_ida); 193} 194 195EXPORT_SYMBOL(w1_ds2760_read); 196EXPORT_SYMBOL(w1_ds2760_write); 197EXPORT_SYMBOL(w1_ds2760_store_eeprom); 198EXPORT_SYMBOL(w1_ds2760_recall_eeprom); 199 200module_init(w1_ds2760_init); 201module_exit(w1_ds2760_exit); 202 203MODULE_LICENSE("GPL"); 204MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>"); 205MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip"); 206MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760)); 207