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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Dallas Semiconductor DS1682 Elapsed Time Recorder device driver
4 *
5 * Written by: Grant Likely <grant.likely@secretlab.ca>
6 *
7 * Copyright (C) 2007 Secret Lab Technologies Ltd.
8 */
9
10/*
11 * The DS1682 elapsed timer recorder is a simple device that implements
12 * one elapsed time counter, one event counter, an alarm signal and 10
13 * bytes of general purpose EEPROM.
14 *
15 * This driver provides access to the DS1682 counters and user data via
16 * the sysfs. The following attributes are added to the device node:
17 * elapsed_time (u32): Total elapsed event time in ms resolution
18 * alarm_time (u32): When elapsed time exceeds the value in alarm_time,
19 * then the alarm pin is asserted.
20 * event_count (u16): number of times the event pin has gone low.
21 * eeprom (u8[10]): general purpose EEPROM
22 *
23 * Counter registers and user data are both read/write unless the device
24 * has been write protected. This driver does not support turning off write
25 * protection. Once write protection is turned on, it is impossible to
26 * turn it off again, so I have left the feature out of this driver to avoid
27 * accidental enabling, but it is trivial to add write protect support.
28 *
29 */
30
31#include <linux/module.h>
32#include <linux/i2c.h>
33#include <linux/string.h>
34#include <linux/list.h>
35#include <linux/sysfs.h>
36#include <linux/ctype.h>
37#include <linux/hwmon-sysfs.h>
38
39/* Device registers */
40#define DS1682_REG_CONFIG 0x00
41#define DS1682_REG_ALARM 0x01
42#define DS1682_REG_ELAPSED 0x05
43#define DS1682_REG_EVT_CNTR 0x09
44#define DS1682_REG_EEPROM 0x0b
45#define DS1682_REG_RESET 0x1d
46#define DS1682_REG_WRITE_DISABLE 0x1e
47#define DS1682_REG_WRITE_MEM_DISABLE 0x1f
48
49#define DS1682_EEPROM_SIZE 10
50
51/*
52 * Generic counter attributes
53 */
54static ssize_t ds1682_show(struct device *dev, struct device_attribute *attr,
55 char *buf)
56{
57 struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
58 struct i2c_client *client = to_i2c_client(dev);
59 unsigned long long val, check;
60 __le32 val_le = 0;
61 int rc;
62
63 dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);
64
65 /* Read the register */
66 rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
67 (u8 *)&val_le);
68 if (rc < 0)
69 return -EIO;
70
71 val = le32_to_cpu(val_le);
72
73 if (sattr->index == DS1682_REG_ELAPSED) {
74 int retries = 5;
75
76 /* Detect and retry when a tick occurs mid-read */
77 do {
78 rc = i2c_smbus_read_i2c_block_data(client, sattr->index,
79 sattr->nr,
80 (u8 *)&val_le);
81 if (rc < 0 || retries <= 0)
82 return -EIO;
83
84 check = val;
85 val = le32_to_cpu(val_le);
86 retries--;
87 } while (val != check && val != (check + 1));
88 }
89
90 /* Format the output string and return # of bytes
91 * Special case: the 32 bit regs are time values with 1/4s
92 * resolution, scale them up to milliseconds
93 */
94 return sprintf(buf, "%llu\n", (sattr->nr == 4) ? (val * 250) : val);
95}
96
97static ssize_t ds1682_store(struct device *dev, struct device_attribute *attr,
98 const char *buf, size_t count)
99{
100 struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
101 struct i2c_client *client = to_i2c_client(dev);
102 u64 val;
103 __le32 val_le;
104 int rc;
105
106 dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name);
107
108 /* Decode input */
109 rc = kstrtoull(buf, 0, &val);
110 if (rc < 0) {
111 dev_dbg(dev, "input string not a number\n");
112 return -EINVAL;
113 }
114
115 /* Special case: the 32 bit regs are time values with 1/4s
116 * resolution, scale input down to quarter-seconds */
117 if (sattr->nr == 4)
118 do_div(val, 250);
119
120 /* write out the value */
121 val_le = cpu_to_le32(val);
122 rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr,
123 (u8 *) & val_le);
124 if (rc < 0) {
125 dev_err(dev, "register write failed; reg=0x%x, size=%i\n",
126 sattr->index, sattr->nr);
127 return -EIO;
128 }
129
130 return count;
131}
132
133/*
134 * Simple register attributes
135 */
136static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO | S_IWUSR, ds1682_show,
137 ds1682_store, 4, DS1682_REG_ELAPSED);
138static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO | S_IWUSR, ds1682_show,
139 ds1682_store, 4, DS1682_REG_ALARM);
140static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO | S_IWUSR, ds1682_show,
141 ds1682_store, 2, DS1682_REG_EVT_CNTR);
142
143static const struct attribute_group ds1682_group = {
144 .attrs = (struct attribute *[]) {
145 &sensor_dev_attr_elapsed_time.dev_attr.attr,
146 &sensor_dev_attr_alarm_time.dev_attr.attr,
147 &sensor_dev_attr_event_count.dev_attr.attr,
148 NULL,
149 },
150};
151
152/*
153 * User data attribute
154 */
155static ssize_t ds1682_eeprom_read(struct file *filp, struct kobject *kobj,
156 struct bin_attribute *attr,
157 char *buf, loff_t off, size_t count)
158{
159 struct i2c_client *client = kobj_to_i2c_client(kobj);
160 int rc;
161
162 dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n",
163 buf, off, count);
164
165 rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off,
166 count, buf);
167 if (rc < 0)
168 return -EIO;
169
170 return count;
171}
172
173static ssize_t ds1682_eeprom_write(struct file *filp, struct kobject *kobj,
174 struct bin_attribute *attr,
175 char *buf, loff_t off, size_t count)
176{
177 struct i2c_client *client = kobj_to_i2c_client(kobj);
178
179 dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n",
180 buf, off, count);
181
182 /* Write out to the device */
183 if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off,
184 count, buf) < 0)
185 return -EIO;
186
187 return count;
188}
189
190static const struct bin_attribute ds1682_eeprom_attr = {
191 .attr = {
192 .name = "eeprom",
193 .mode = S_IRUGO | S_IWUSR,
194 },
195 .size = DS1682_EEPROM_SIZE,
196 .read = ds1682_eeprom_read,
197 .write = ds1682_eeprom_write,
198};
199
200/*
201 * Called when a ds1682 device is matched with this driver
202 */
203static int ds1682_probe(struct i2c_client *client)
204{
205 int rc;
206
207 if (!i2c_check_functionality(client->adapter,
208 I2C_FUNC_SMBUS_I2C_BLOCK)) {
209 dev_err(&client->dev, "i2c bus does not support the ds1682\n");
210 rc = -ENODEV;
211 goto exit;
212 }
213
214 rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
215 if (rc)
216 goto exit;
217
218 rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
219 if (rc)
220 goto exit_bin_attr;
221
222 return 0;
223
224 exit_bin_attr:
225 sysfs_remove_group(&client->dev.kobj, &ds1682_group);
226 exit:
227 return rc;
228}
229
230static void ds1682_remove(struct i2c_client *client)
231{
232 sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
233 sysfs_remove_group(&client->dev.kobj, &ds1682_group);
234}
235
236static const struct i2c_device_id ds1682_id[] = {
237 { "ds1682", 0 },
238 { }
239};
240MODULE_DEVICE_TABLE(i2c, ds1682_id);
241
242static const struct of_device_id ds1682_of_match[] = {
243 { .compatible = "dallas,ds1682", },
244 {}
245};
246MODULE_DEVICE_TABLE(of, ds1682_of_match);
247
248static struct i2c_driver ds1682_driver = {
249 .driver = {
250 .name = "ds1682",
251 .of_match_table = ds1682_of_match,
252 },
253 .probe = ds1682_probe,
254 .remove = ds1682_remove,
255 .id_table = ds1682_id,
256};
257
258module_i2c_driver(ds1682_driver);
259
260MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
261MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
262MODULE_LICENSE("GPL");
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>
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 */
57static 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 unsigned long long val, check;
63 __le32 val_le = 0;
64 int rc;
65
66 dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);
67
68 /* Read the register */
69 rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
70 (u8 *)&val_le);
71 if (rc < 0)
72 return -EIO;
73
74 val = le32_to_cpu(val_le);
75
76 if (sattr->index == DS1682_REG_ELAPSED) {
77 int retries = 5;
78
79 /* Detect and retry when a tick occurs mid-read */
80 do {
81 rc = i2c_smbus_read_i2c_block_data(client, sattr->index,
82 sattr->nr,
83 (u8 *)&val_le);
84 if (rc < 0 || retries <= 0)
85 return -EIO;
86
87 check = val;
88 val = le32_to_cpu(val_le);
89 retries--;
90 } while (val != check && val != (check + 1));
91 }
92
93 /* Format the output string and return # of bytes
94 * Special case: the 32 bit regs are time values with 1/4s
95 * resolution, scale them up to milliseconds
96 */
97 return sprintf(buf, "%llu\n", (sattr->nr == 4) ? (val * 250) : val);
98}
99
100static ssize_t ds1682_store(struct device *dev, struct device_attribute *attr,
101 const char *buf, size_t count)
102{
103 struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
104 struct i2c_client *client = to_i2c_client(dev);
105 u64 val;
106 __le32 val_le;
107 int rc;
108
109 dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name);
110
111 /* Decode input */
112 rc = kstrtoull(buf, 0, &val);
113 if (rc < 0) {
114 dev_dbg(dev, "input string not a number\n");
115 return -EINVAL;
116 }
117
118 /* Special case: the 32 bit regs are time values with 1/4s
119 * resolution, scale input down to quarter-seconds */
120 if (sattr->nr == 4)
121 do_div(val, 250);
122
123 /* write out the value */
124 val_le = cpu_to_le32(val);
125 rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr,
126 (u8 *) & val_le);
127 if (rc < 0) {
128 dev_err(dev, "register write failed; reg=0x%x, size=%i\n",
129 sattr->index, sattr->nr);
130 return -EIO;
131 }
132
133 return count;
134}
135
136/*
137 * Simple register attributes
138 */
139static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO | S_IWUSR, ds1682_show,
140 ds1682_store, 4, DS1682_REG_ELAPSED);
141static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO | S_IWUSR, ds1682_show,
142 ds1682_store, 4, DS1682_REG_ALARM);
143static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO | S_IWUSR, ds1682_show,
144 ds1682_store, 2, DS1682_REG_EVT_CNTR);
145
146static const struct attribute_group ds1682_group = {
147 .attrs = (struct attribute *[]) {
148 &sensor_dev_attr_elapsed_time.dev_attr.attr,
149 &sensor_dev_attr_alarm_time.dev_attr.attr,
150 &sensor_dev_attr_event_count.dev_attr.attr,
151 NULL,
152 },
153};
154
155/*
156 * User data attribute
157 */
158static ssize_t ds1682_eeprom_read(struct file *filp, struct kobject *kobj,
159 struct bin_attribute *attr,
160 char *buf, loff_t off, size_t count)
161{
162 struct i2c_client *client = kobj_to_i2c_client(kobj);
163 int rc;
164
165 dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n",
166 buf, off, count);
167
168 rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off,
169 count, buf);
170 if (rc < 0)
171 return -EIO;
172
173 return count;
174}
175
176static ssize_t ds1682_eeprom_write(struct file *filp, struct kobject *kobj,
177 struct bin_attribute *attr,
178 char *buf, loff_t off, size_t count)
179{
180 struct i2c_client *client = kobj_to_i2c_client(kobj);
181
182 dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n",
183 buf, off, count);
184
185 /* Write out to the device */
186 if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off,
187 count, buf) < 0)
188 return -EIO;
189
190 return count;
191}
192
193static const struct bin_attribute ds1682_eeprom_attr = {
194 .attr = {
195 .name = "eeprom",
196 .mode = S_IRUGO | S_IWUSR,
197 },
198 .size = DS1682_EEPROM_SIZE,
199 .read = ds1682_eeprom_read,
200 .write = ds1682_eeprom_write,
201};
202
203/*
204 * Called when a ds1682 device is matched with this driver
205 */
206static int ds1682_probe(struct i2c_client *client,
207 const struct i2c_device_id *id)
208{
209 int rc;
210
211 if (!i2c_check_functionality(client->adapter,
212 I2C_FUNC_SMBUS_I2C_BLOCK)) {
213 dev_err(&client->dev, "i2c bus does not support the ds1682\n");
214 rc = -ENODEV;
215 goto exit;
216 }
217
218 rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
219 if (rc)
220 goto exit;
221
222 rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
223 if (rc)
224 goto exit_bin_attr;
225
226 return 0;
227
228 exit_bin_attr:
229 sysfs_remove_group(&client->dev.kobj, &ds1682_group);
230 exit:
231 return rc;
232}
233
234static int ds1682_remove(struct i2c_client *client)
235{
236 sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
237 sysfs_remove_group(&client->dev.kobj, &ds1682_group);
238 return 0;
239}
240
241static const struct i2c_device_id ds1682_id[] = {
242 { "ds1682", 0 },
243 { }
244};
245MODULE_DEVICE_TABLE(i2c, ds1682_id);
246
247static const struct of_device_id ds1682_of_match[] = {
248 { .compatible = "dallas,ds1682", },
249 {}
250};
251MODULE_DEVICE_TABLE(of, ds1682_of_match);
252
253static struct i2c_driver ds1682_driver = {
254 .driver = {
255 .name = "ds1682",
256 .of_match_table = ds1682_of_match,
257 },
258 .probe = ds1682_probe,
259 .remove = ds1682_remove,
260 .id_table = ds1682_id,
261};
262
263module_i2c_driver(ds1682_driver);
264
265MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
266MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
267MODULE_LICENSE("GPL");