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 <linux/w1.h> 25 26 #include "w1_ds2780.h" 27 28 #define W1_FAMILY_DS2780 0x32 29 30 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr, 31 size_t count, int io) 32 { 33 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 34 35 if (addr > DS2780_DATA_SIZE || addr < 0) 36 return 0; 37 38 count = min_t(int, count, DS2780_DATA_SIZE - addr); 39 40 if (w1_reset_select_slave(sl) == 0) { 41 if (io) { 42 w1_write_8(sl->master, W1_DS2780_WRITE_DATA); 43 w1_write_8(sl->master, addr); 44 w1_write_block(sl->master, buf, count); 45 } else { 46 w1_write_8(sl->master, W1_DS2780_READ_DATA); 47 w1_write_8(sl->master, addr); 48 count = w1_read_block(sl->master, buf, count); 49 } 50 } 51 52 return count; 53 } 54 55 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count, 56 int io) 57 { 58 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 59 int ret; 60 61 if (!dev) 62 return -ENODEV; 63 64 mutex_lock(&sl->master->bus_mutex); 65 66 ret = w1_ds2780_do_io(dev, buf, addr, count, io); 67 68 mutex_unlock(&sl->master->bus_mutex); 69 70 return ret; 71 } 72 EXPORT_SYMBOL(w1_ds2780_io); 73 74 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd) 75 { 76 struct w1_slave *sl = container_of(dev, struct w1_slave, dev); 77 78 if (!dev) 79 return -EINVAL; 80 81 mutex_lock(&sl->master->bus_mutex); 82 83 if (w1_reset_select_slave(sl) == 0) { 84 w1_write_8(sl->master, cmd); 85 w1_write_8(sl->master, addr); 86 } 87 88 mutex_unlock(&sl->master->bus_mutex); 89 return 0; 90 } 91 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); 92 93 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj, 94 struct bin_attribute *bin_attr, char *buf, 95 loff_t off, size_t count) 96 { 97 struct device *dev = container_of(kobj, struct device, kobj); 98 return w1_ds2780_io(dev, buf, off, count, 0); 99 } 100 101 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE); 102 103 static struct bin_attribute *w1_ds2780_bin_attrs[] = { 104 &bin_attr_w1_slave, 105 NULL, 106 }; 107 108 static const struct attribute_group w1_ds2780_group = { 109 .bin_attrs = w1_ds2780_bin_attrs, 110 }; 111 112 static const struct attribute_group *w1_ds2780_groups[] = { 113 &w1_ds2780_group, 114 NULL, 115 }; 116 117 static int w1_ds2780_add_slave(struct w1_slave *sl) 118 { 119 int ret; 120 struct platform_device *pdev; 121 122 pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO); 123 if (!pdev) 124 return -ENOMEM; 125 pdev->dev.parent = &sl->dev; 126 127 ret = platform_device_add(pdev); 128 if (ret) 129 goto pdev_add_failed; 130 131 dev_set_drvdata(&sl->dev, pdev); 132 133 return 0; 134 135 pdev_add_failed: 136 platform_device_put(pdev); 137 138 return ret; 139 } 140 141 static void w1_ds2780_remove_slave(struct w1_slave *sl) 142 { 143 struct platform_device *pdev = dev_get_drvdata(&sl->dev); 144 145 platform_device_unregister(pdev); 146 } 147 148 static struct w1_family_ops w1_ds2780_fops = { 149 .add_slave = w1_ds2780_add_slave, 150 .remove_slave = w1_ds2780_remove_slave, 151 .groups = w1_ds2780_groups, 152 }; 153 154 static struct w1_family w1_ds2780_family = { 155 .fid = W1_FAMILY_DS2780, 156 .fops = &w1_ds2780_fops, 157 }; 158 module_w1_family(w1_ds2780_family); 159 160 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>"); 161 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC"); 162 MODULE_LICENSE("GPL"); 163 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780)); 164