Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Dallas Semiconductor DS1682 Elapsed Time Recorder device driver |
| 3 | * |
| 4 | * Written by: Grant Likely <grant.likely@secretlab.ca> |
| 5 | * |
| 6 | * Copyright (C) 2007 Secret Lab Technologies Ltd. |
| 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 | * The DS1682 elapsed timer recorder is a simple device that implements |
| 15 | * one elapsed time counter, one event counter, an alarm signal and 10 |
| 16 | * bytes of general purpose EEPROM. |
| 17 | * |
| 18 | * This driver provides access to the DS1682 counters and user data via |
| 19 | * the sysfs. The following attributes are added to the device node: |
| 20 | * elapsed_time (u32): Total elapsed event time in ms resolution |
| 21 | * alarm_time (u32): When elapsed time exceeds the value in alarm_time, |
| 22 | * then the alarm pin is asserted. |
| 23 | * event_count (u16): number of times the event pin has gone low. |
| 24 | * eeprom (u8[10]): general purpose EEPROM |
| 25 | * |
| 26 | * Counter registers and user data are both read/write unless the device |
| 27 | * has been write protected. This driver does not support turning off write |
| 28 | * protection. Once write protection is turned on, it is impossible to |
| 29 | * turn it off again, so I have left the feature out of this driver to avoid |
| 30 | * accidental enabling, but it is trivial to add write protect support. |
| 31 | * |
| 32 | */ |
| 33 | |
| 34 | #include <linux/module.h> |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 35 | #include <linux/i2c.h> |
| 36 | #include <linux/string.h> |
| 37 | #include <linux/list.h> |
| 38 | #include <linux/sysfs.h> |
| 39 | #include <linux/ctype.h> |
| 40 | #include <linux/hwmon-sysfs.h> |
| 41 | |
| 42 | /* Device registers */ |
| 43 | #define DS1682_REG_CONFIG 0x00 |
| 44 | #define DS1682_REG_ALARM 0x01 |
| 45 | #define DS1682_REG_ELAPSED 0x05 |
| 46 | #define DS1682_REG_EVT_CNTR 0x09 |
| 47 | #define DS1682_REG_EEPROM 0x0b |
| 48 | #define DS1682_REG_RESET 0x1d |
| 49 | #define DS1682_REG_WRITE_DISABLE 0x1e |
| 50 | #define DS1682_REG_WRITE_MEM_DISABLE 0x1f |
| 51 | |
| 52 | #define DS1682_EEPROM_SIZE 10 |
| 53 | |
| 54 | /* |
| 55 | * Generic counter attributes |
| 56 | */ |
| 57 | static ssize_t ds1682_show(struct device *dev, struct device_attribute *attr, |
| 58 | char *buf) |
| 59 | { |
| 60 | struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr); |
| 61 | struct i2c_client *client = to_i2c_client(dev); |
| 62 | __le32 val = 0; |
| 63 | int rc; |
| 64 | |
| 65 | dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name); |
| 66 | |
| 67 | /* Read the register */ |
| 68 | rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr, |
| 69 | (u8 *) & val); |
| 70 | if (rc < 0) |
| 71 | return -EIO; |
| 72 | |
| 73 | /* Special case: the 32 bit regs are time values with 1/4s |
| 74 | * resolution, scale them up to milliseconds */ |
| 75 | if (sattr->nr == 4) |
Andrew Morton | f52e0ef | 2007-07-26 10:41:09 -0700 | [diff] [blame] | 76 | return sprintf(buf, "%llu\n", |
| 77 | ((unsigned long long)le32_to_cpu(val)) * 250); |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 78 | |
| 79 | /* Format the output string and return # of bytes */ |
| 80 | return sprintf(buf, "%li\n", (long)le32_to_cpu(val)); |
| 81 | } |
| 82 | |
| 83 | static ssize_t ds1682_store(struct device *dev, struct device_attribute *attr, |
| 84 | const char *buf, size_t count) |
| 85 | { |
| 86 | struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr); |
| 87 | struct i2c_client *client = to_i2c_client(dev); |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 88 | u64 val; |
| 89 | __le32 val_le; |
| 90 | int rc; |
| 91 | |
| 92 | dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name); |
| 93 | |
| 94 | /* Decode input */ |
Sebastien Bourdelin | 4030074 | 2014-04-01 11:04:28 -0400 | [diff] [blame] | 95 | rc = kstrtoull(buf, 0, &val); |
| 96 | if (rc < 0) { |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 97 | dev_dbg(dev, "input string not a number\n"); |
| 98 | return -EINVAL; |
| 99 | } |
| 100 | |
| 101 | /* Special case: the 32 bit regs are time values with 1/4s |
| 102 | * resolution, scale input down to quarter-seconds */ |
| 103 | if (sattr->nr == 4) |
| 104 | do_div(val, 250); |
| 105 | |
| 106 | /* write out the value */ |
| 107 | val_le = cpu_to_le32(val); |
| 108 | rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr, |
| 109 | (u8 *) & val_le); |
| 110 | if (rc < 0) { |
| 111 | dev_err(dev, "register write failed; reg=0x%x, size=%i\n", |
| 112 | sattr->index, sattr->nr); |
| 113 | return -EIO; |
| 114 | } |
| 115 | |
| 116 | return count; |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * Simple register attributes |
| 121 | */ |
| 122 | static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO | S_IWUSR, ds1682_show, |
| 123 | ds1682_store, 4, DS1682_REG_ELAPSED); |
| 124 | static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO | S_IWUSR, ds1682_show, |
| 125 | ds1682_store, 4, DS1682_REG_ALARM); |
| 126 | static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO | S_IWUSR, ds1682_show, |
| 127 | ds1682_store, 2, DS1682_REG_EVT_CNTR); |
| 128 | |
| 129 | static const struct attribute_group ds1682_group = { |
| 130 | .attrs = (struct attribute *[]) { |
| 131 | &sensor_dev_attr_elapsed_time.dev_attr.attr, |
| 132 | &sensor_dev_attr_alarm_time.dev_attr.attr, |
| 133 | &sensor_dev_attr_event_count.dev_attr.attr, |
| 134 | NULL, |
| 135 | }, |
| 136 | }; |
| 137 | |
| 138 | /* |
| 139 | * User data attribute |
| 140 | */ |
Chris Wright | 2c3c8be | 2010-05-12 18:28:57 -0700 | [diff] [blame] | 141 | static ssize_t ds1682_eeprom_read(struct file *filp, struct kobject *kobj, |
| 142 | struct bin_attribute *attr, |
Al Viro | 05bd711 | 2007-07-15 21:01:22 +0100 | [diff] [blame] | 143 | char *buf, loff_t off, size_t count) |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 144 | { |
| 145 | struct i2c_client *client = kobj_to_i2c_client(kobj); |
| 146 | int rc; |
| 147 | |
| 148 | dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n", |
| 149 | buf, off, count); |
| 150 | |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 151 | rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off, |
| 152 | count, buf); |
| 153 | if (rc < 0) |
| 154 | return -EIO; |
| 155 | |
| 156 | return count; |
| 157 | } |
| 158 | |
Chris Wright | 2c3c8be | 2010-05-12 18:28:57 -0700 | [diff] [blame] | 159 | static ssize_t ds1682_eeprom_write(struct file *filp, struct kobject *kobj, |
| 160 | struct bin_attribute *attr, |
Al Viro | 05bd711 | 2007-07-15 21:01:22 +0100 | [diff] [blame] | 161 | char *buf, loff_t off, size_t count) |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 162 | { |
| 163 | struct i2c_client *client = kobj_to_i2c_client(kobj); |
| 164 | |
| 165 | dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n", |
| 166 | buf, off, count); |
| 167 | |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 168 | /* Write out to the device */ |
| 169 | if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off, |
| 170 | count, buf) < 0) |
| 171 | return -EIO; |
| 172 | |
| 173 | return count; |
| 174 | } |
| 175 | |
| 176 | static struct bin_attribute ds1682_eeprom_attr = { |
| 177 | .attr = { |
| 178 | .name = "eeprom", |
| 179 | .mode = S_IRUGO | S_IWUSR, |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 180 | }, |
| 181 | .size = DS1682_EEPROM_SIZE, |
| 182 | .read = ds1682_eeprom_read, |
| 183 | .write = ds1682_eeprom_write, |
| 184 | }; |
| 185 | |
| 186 | /* |
| 187 | * Called when a ds1682 device is matched with this driver |
| 188 | */ |
Jean Delvare | d2653e9 | 2008-04-29 23:11:39 +0200 | [diff] [blame] | 189 | static int ds1682_probe(struct i2c_client *client, |
| 190 | const struct i2c_device_id *id) |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 191 | { |
| 192 | int rc; |
| 193 | |
| 194 | if (!i2c_check_functionality(client->adapter, |
| 195 | I2C_FUNC_SMBUS_I2C_BLOCK)) { |
| 196 | dev_err(&client->dev, "i2c bus does not support the ds1682\n"); |
| 197 | rc = -ENODEV; |
| 198 | goto exit; |
| 199 | } |
| 200 | |
| 201 | rc = sysfs_create_group(&client->dev.kobj, &ds1682_group); |
| 202 | if (rc) |
| 203 | goto exit; |
| 204 | |
| 205 | rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr); |
| 206 | if (rc) |
| 207 | goto exit_bin_attr; |
| 208 | |
| 209 | return 0; |
| 210 | |
| 211 | exit_bin_attr: |
| 212 | sysfs_remove_group(&client->dev.kobj, &ds1682_group); |
| 213 | exit: |
| 214 | return rc; |
| 215 | } |
| 216 | |
| 217 | static int ds1682_remove(struct i2c_client *client) |
| 218 | { |
| 219 | sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr); |
| 220 | sysfs_remove_group(&client->dev.kobj, &ds1682_group); |
| 221 | return 0; |
| 222 | } |
| 223 | |
Jean Delvare | 3760f73 | 2008-04-29 23:11:40 +0200 | [diff] [blame] | 224 | static const struct i2c_device_id ds1682_id[] = { |
| 225 | { "ds1682", 0 }, |
| 226 | { } |
| 227 | }; |
| 228 | MODULE_DEVICE_TABLE(i2c, ds1682_id); |
| 229 | |
Javier Martinez Canillas | 5ef1685 | 2017-03-21 10:50:48 -0300 | [diff] [blame] | 230 | static const struct of_device_id ds1682_of_match[] = { |
| 231 | { .compatible = "dallas,ds1682", }, |
| 232 | {} |
| 233 | }; |
| 234 | MODULE_DEVICE_TABLE(of, ds1682_of_match); |
| 235 | |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 236 | static struct i2c_driver ds1682_driver = { |
| 237 | .driver = { |
| 238 | .name = "ds1682", |
Javier Martinez Canillas | 5ef1685 | 2017-03-21 10:50:48 -0300 | [diff] [blame] | 239 | .of_match_table = ds1682_of_match, |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 240 | }, |
| 241 | .probe = ds1682_probe, |
| 242 | .remove = ds1682_remove, |
Jean Delvare | 3760f73 | 2008-04-29 23:11:40 +0200 | [diff] [blame] | 243 | .id_table = ds1682_id, |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 244 | }; |
| 245 | |
Axel Lin | a64fe2e | 2012-01-22 15:36:45 +0800 | [diff] [blame] | 246 | module_i2c_driver(ds1682_driver); |
Grant Likely | 5162b75 | 2007-07-12 14:12:29 +0200 | [diff] [blame] | 247 | |
| 248 | MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>"); |
| 249 | MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver"); |
| 250 | MODULE_LICENSE("GPL"); |