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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 | // SPDX-License-Identifier: GPL-2.0-or-later /* * lm77.c - Part of lm_sensors, Linux kernel modules for hardware * monitoring * * Copyright (c) 2004 Andras BALI <drewie@freemail.hu> * * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77 * is a temperature sensor and thermal window comparator with 0.5 deg * resolution made by National Semiconductor. Complete datasheet can be * obtained at their site: * http://www.national.com/pf/LM/LM77.html */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/jiffies.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/mutex.h> /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; /* The LM77 registers */ #define LM77_REG_TEMP 0x00 #define LM77_REG_CONF 0x01 #define LM77_REG_TEMP_HYST 0x02 #define LM77_REG_TEMP_CRIT 0x03 #define LM77_REG_TEMP_MIN 0x04 #define LM77_REG_TEMP_MAX 0x05 enum temp_index { t_input = 0, t_crit, t_min, t_max, t_hyst, t_num_temp }; static const u8 temp_regs[t_num_temp] = { [t_input] = LM77_REG_TEMP, [t_min] = LM77_REG_TEMP_MIN, [t_max] = LM77_REG_TEMP_MAX, [t_crit] = LM77_REG_TEMP_CRIT, [t_hyst] = LM77_REG_TEMP_HYST, }; /* Each client has this additional data */ struct lm77_data { struct i2c_client *client; struct mutex update_lock; char valid; unsigned long last_updated; /* In jiffies */ int temp[t_num_temp]; /* index using temp_index */ u8 alarms; }; /* straight from the datasheet */ #define LM77_TEMP_MIN (-55000) #define LM77_TEMP_MAX 125000 /* * In the temperature registers, the low 3 bits are not part of the * temperature values; they are the status bits. */ static inline s16 LM77_TEMP_TO_REG(int temp) { return (temp / 500) * 8; } static inline int LM77_TEMP_FROM_REG(s16 reg) { return (reg / 8) * 500; } /* * All registers are word-sized, except for the configuration register. * The LM77 uses the high-byte first convention. */ static u16 lm77_read_value(struct i2c_client *client, u8 reg) { if (reg == LM77_REG_CONF) return i2c_smbus_read_byte_data(client, reg); else return i2c_smbus_read_word_swapped(client, reg); } static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) { if (reg == LM77_REG_CONF) return i2c_smbus_write_byte_data(client, reg, value); else return i2c_smbus_write_word_swapped(client, reg, value); } static struct lm77_data *lm77_update_device(struct device *dev) { struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int i; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ + HZ / 2) || !data->valid) { dev_dbg(&client->dev, "Starting lm77 update\n"); for (i = 0; i < t_num_temp; i++) { data->temp[i] = LM77_TEMP_FROM_REG(lm77_read_value(client, temp_regs[i])); } data->alarms = lm77_read_value(client, LM77_REG_TEMP) & 0x0007; data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->update_lock); return data; } /* sysfs stuff */ static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = lm77_update_device(dev); return sprintf(buf, "%d\n", data->temp[attr->index]); } static ssize_t temp_hyst_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = lm77_update_device(dev); int nr = attr->index; int temp; temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] : data->temp[nr] - data->temp[t_hyst]; return sprintf(buf, "%d\n", temp); } static ssize_t temp_store(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int nr = attr->index; long val; int err; err = kstrtol(buf, 10, &val); if (err) return err; val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX); mutex_lock(&data->update_lock); data->temp[nr] = val; lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val)); mutex_unlock(&data->update_lock); return count; } /* * hysteresis is stored as a relative value on the chip, so it has to be * converted first. */ static ssize_t temp_hyst_store(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; long val; int err; err = kstrtol(buf, 10, &val); if (err) return err; mutex_lock(&data->update_lock); val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX); data->temp[t_hyst] = val; lm77_write_value(client, LM77_REG_TEMP_HYST, LM77_TEMP_TO_REG(data->temp[t_hyst])); mutex_unlock(&data->update_lock); return count; } static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, char *buf) { int bitnr = to_sensor_dev_attr(attr)->index; struct lm77_data *data = lm77_update_device(dev); return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); } static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input); static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit); static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min); static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max); static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit); static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, temp_hyst, t_min); static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max); static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2); static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0); static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1); static struct attribute *lm77_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp1_crit.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, &sensor_dev_attr_temp1_min_hyst.dev_attr.attr, &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, NULL }; ATTRIBUTE_GROUPS(lm77); /* Return 0 if detection is successful, -ENODEV otherwise */ static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; int i, cur, conf, hyst, crit, min, max; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; /* * Here comes the remaining detection. Since the LM77 has no * register dedicated to identification, we have to rely on the * following tricks: * * 1. the high 4 bits represent the sign and thus they should * always be the same * 2. the high 3 bits are unused in the configuration register * 3. addresses 0x06 and 0x07 return the last read value * 4. registers cycling over 8-address boundaries * * Word-sized registers are high-byte first. */ /* addresses cycling */ cur = i2c_smbus_read_word_data(client, 0); conf = i2c_smbus_read_byte_data(client, 1); hyst = i2c_smbus_read_word_data(client, 2); crit = i2c_smbus_read_word_data(client, 3); min = i2c_smbus_read_word_data(client, 4); max = i2c_smbus_read_word_data(client, 5); for (i = 8; i <= 0xff; i += 8) { if (i2c_smbus_read_byte_data(client, i + 1) != conf || i2c_smbus_read_word_data(client, i + 2) != hyst || i2c_smbus_read_word_data(client, i + 3) != crit || i2c_smbus_read_word_data(client, i + 4) != min || i2c_smbus_read_word_data(client, i + 5) != max) return -ENODEV; } /* sign bits */ if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) return -ENODEV; /* unused bits */ if (conf & 0xe0) return -ENODEV; /* 0x06 and 0x07 return the last read value */ cur = i2c_smbus_read_word_data(client, 0); if (i2c_smbus_read_word_data(client, 6) != cur || i2c_smbus_read_word_data(client, 7) != cur) return -ENODEV; hyst = i2c_smbus_read_word_data(client, 2); if (i2c_smbus_read_word_data(client, 6) != hyst || i2c_smbus_read_word_data(client, 7) != hyst) return -ENODEV; min = i2c_smbus_read_word_data(client, 4); if (i2c_smbus_read_word_data(client, 6) != min || i2c_smbus_read_word_data(client, 7) != min) return -ENODEV; strlcpy(info->type, "lm77", I2C_NAME_SIZE); return 0; } static void lm77_init_client(struct i2c_client *client) { /* Initialize the LM77 chip - turn off shutdown mode */ int conf = lm77_read_value(client, LM77_REG_CONF); if (conf & 1) lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); } static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct device *hwmon_dev; struct lm77_data *data; data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; mutex_init(&data->update_lock); /* Initialize the LM77 chip */ lm77_init_client(client); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, lm77_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id lm77_id[] = { { "lm77", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, lm77_id); /* This is the driver that will be inserted */ static struct i2c_driver lm77_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "lm77", }, .probe = lm77_probe, .id_table = lm77_id, .detect = lm77_detect, .address_list = normal_i2c, }; module_i2c_driver(lm77_driver); MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); MODULE_DESCRIPTION("LM77 driver"); MODULE_LICENSE("GPL"); |