1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LM73 Sensor driver 4 * Based on LM75 5 * 6 * Copyright (C) 2007, CenoSYS (www.cenosys.com). 7 * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu). 8 * 9 * Guillaume Ligneul <guillaume.ligneul@gmail.com> 10 * Adrien Demarez <adrien.demarez@bolloretelecom.eu> 11 * Jeremy Laine <jeremy.laine@bolloretelecom.eu> 12 * Chris Verges <kg4ysn@gmail.com> 13 */ 14 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/i2c.h> 18 #include <linux/hwmon.h> 19 #include <linux/hwmon-sysfs.h> 20 #include <linux/err.h> 21 22 23 /* Addresses scanned */ 24 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, 25 0x4d, 0x4e, I2C_CLIENT_END }; 26 27 /* LM73 registers */ 28 #define LM73_REG_INPUT 0x00 29 #define LM73_REG_CONF 0x01 30 #define LM73_REG_MAX 0x02 31 #define LM73_REG_MIN 0x03 32 #define LM73_REG_CTRL 0x04 33 #define LM73_REG_ID 0x07 34 35 #define LM73_ID 0x9001 /* 0x0190, byte-swapped */ 36 #define DRVNAME "lm73" 37 #define LM73_TEMP_MIN (-256000 / 250) 38 #define LM73_TEMP_MAX (255750 / 250) 39 40 #define LM73_CTRL_RES_SHIFT 5 41 #define LM73_CTRL_RES_MASK (BIT(5) | BIT(6)) 42 #define LM73_CTRL_TO_MASK BIT(7) 43 44 #define LM73_CTRL_HI_SHIFT 2 45 #define LM73_CTRL_LO_SHIFT 1 46 47 static const unsigned short lm73_convrates[] = { 48 14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */ 49 28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */ 50 56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */ 51 112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */ 52 }; 53 54 struct lm73_data { 55 struct i2c_client *client; 56 struct mutex lock; 57 u8 ctrl; /* control register value */ 58 }; 59 60 /*-----------------------------------------------------------------------*/ 61 62 static ssize_t temp_store(struct device *dev, struct device_attribute *da, 63 const char *buf, size_t count) 64 { 65 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 66 struct lm73_data *data = dev_get_drvdata(dev); 67 long temp; 68 short value; 69 s32 err; 70 71 int status = kstrtol(buf, 10, &temp); 72 if (status < 0) 73 return status; 74 75 /* Write value */ 76 value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5; 77 err = i2c_smbus_write_word_swapped(data->client, attr->index, value); 78 return (err < 0) ? err : count; 79 } 80 81 static ssize_t temp_show(struct device *dev, struct device_attribute *da, 82 char *buf) 83 { 84 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 85 struct lm73_data *data = dev_get_drvdata(dev); 86 int temp; 87 88 s32 err = i2c_smbus_read_word_swapped(data->client, attr->index); 89 if (err < 0) 90 return err; 91 92 /* use integer division instead of equivalent right shift to 93 guarantee arithmetic shift and preserve the sign */ 94 temp = (((s16) err) * 250) / 32; 95 return scnprintf(buf, PAGE_SIZE, "%d\n", temp); 96 } 97 98 static ssize_t convrate_store(struct device *dev, struct device_attribute *da, 99 const char *buf, size_t count) 100 { 101 struct lm73_data *data = dev_get_drvdata(dev); 102 unsigned long convrate; 103 s32 err; 104 int res = 0; 105 106 err = kstrtoul(buf, 10, &convrate); 107 if (err < 0) 108 return err; 109 110 /* 111 * Convert the desired conversion rate into register bits. 112 * res is already initialized, and everything past the second-to-last 113 * value in the array is treated as belonging to the last value 114 * in the array. 115 */ 116 while (res < (ARRAY_SIZE(lm73_convrates) - 1) && 117 convrate > lm73_convrates[res]) 118 res++; 119 120 mutex_lock(&data->lock); 121 data->ctrl &= LM73_CTRL_TO_MASK; 122 data->ctrl |= res << LM73_CTRL_RES_SHIFT; 123 err = i2c_smbus_write_byte_data(data->client, LM73_REG_CTRL, 124 data->ctrl); 125 mutex_unlock(&data->lock); 126 127 if (err < 0) 128 return err; 129 130 return count; 131 } 132 133 static ssize_t convrate_show(struct device *dev, struct device_attribute *da, 134 char *buf) 135 { 136 struct lm73_data *data = dev_get_drvdata(dev); 137 int res; 138 139 res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT; 140 return scnprintf(buf, PAGE_SIZE, "%hu\n", lm73_convrates[res]); 141 } 142 143 static ssize_t maxmin_alarm_show(struct device *dev, 144 struct device_attribute *da, char *buf) 145 { 146 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 147 struct lm73_data *data = dev_get_drvdata(dev); 148 s32 ctrl; 149 150 mutex_lock(&data->lock); 151 ctrl = i2c_smbus_read_byte_data(data->client, LM73_REG_CTRL); 152 if (ctrl < 0) 153 goto abort; 154 data->ctrl = ctrl; 155 mutex_unlock(&data->lock); 156 157 return scnprintf(buf, PAGE_SIZE, "%d\n", (ctrl >> attr->index) & 1); 158 159 abort: 160 mutex_unlock(&data->lock); 161 return ctrl; 162 } 163 164 /*-----------------------------------------------------------------------*/ 165 166 /* sysfs attributes for hwmon */ 167 168 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, LM73_REG_MAX); 169 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, LM73_REG_MIN); 170 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, LM73_REG_INPUT); 171 static SENSOR_DEVICE_ATTR_RW(update_interval, convrate, 0); 172 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, maxmin_alarm, 173 LM73_CTRL_HI_SHIFT); 174 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, maxmin_alarm, 175 LM73_CTRL_LO_SHIFT); 176 177 static struct attribute *lm73_attrs[] = { 178 &sensor_dev_attr_temp1_input.dev_attr.attr, 179 &sensor_dev_attr_temp1_max.dev_attr.attr, 180 &sensor_dev_attr_temp1_min.dev_attr.attr, 181 &sensor_dev_attr_update_interval.dev_attr.attr, 182 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 183 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 184 NULL 185 }; 186 ATTRIBUTE_GROUPS(lm73); 187 188 /*-----------------------------------------------------------------------*/ 189 190 /* device probe and removal */ 191 192 static int 193 lm73_probe(struct i2c_client *client) 194 { 195 struct device *dev = &client->dev; 196 struct device *hwmon_dev; 197 struct lm73_data *data; 198 int ctrl; 199 200 data = devm_kzalloc(dev, sizeof(struct lm73_data), GFP_KERNEL); 201 if (!data) 202 return -ENOMEM; 203 204 data->client = client; 205 mutex_init(&data->lock); 206 207 ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL); 208 if (ctrl < 0) 209 return ctrl; 210 data->ctrl = ctrl; 211 212 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 213 data, lm73_groups); 214 if (IS_ERR(hwmon_dev)) 215 return PTR_ERR(hwmon_dev); 216 217 dev_info(dev, "sensor '%s'\n", client->name); 218 219 return 0; 220 } 221 222 static const struct i2c_device_id lm73_ids[] = { 223 { "lm73", 0 }, 224 { /* LIST END */ } 225 }; 226 MODULE_DEVICE_TABLE(i2c, lm73_ids); 227 228 /* Return 0 if detection is successful, -ENODEV otherwise */ 229 static int lm73_detect(struct i2c_client *new_client, 230 struct i2c_board_info *info) 231 { 232 struct i2c_adapter *adapter = new_client->adapter; 233 int id, ctrl, conf; 234 235 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 236 I2C_FUNC_SMBUS_WORD_DATA)) 237 return -ENODEV; 238 239 /* 240 * Do as much detection as possible with byte reads first, as word 241 * reads can confuse other devices. 242 */ 243 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 244 if (ctrl < 0 || (ctrl & 0x10)) 245 return -ENODEV; 246 247 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF); 248 if (conf < 0 || (conf & 0x0c)) 249 return -ENODEV; 250 251 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID); 252 if (id < 0 || id != (LM73_ID & 0xff)) 253 return -ENODEV; 254 255 /* Check device ID */ 256 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 257 if (id < 0 || id != LM73_ID) 258 return -ENODEV; 259 260 strscpy(info->type, "lm73", I2C_NAME_SIZE); 261 262 return 0; 263 } 264 265 static const struct of_device_id lm73_of_match[] = { 266 { 267 .compatible = "ti,lm73", 268 }, 269 { }, 270 }; 271 272 MODULE_DEVICE_TABLE(of, lm73_of_match); 273 274 static struct i2c_driver lm73_driver = { 275 .class = I2C_CLASS_HWMON, 276 .driver = { 277 .name = "lm73", 278 .of_match_table = lm73_of_match, 279 }, 280 .probe_new = lm73_probe, 281 .id_table = lm73_ids, 282 .detect = lm73_detect, 283 .address_list = normal_i2c, 284 }; 285 286 module_i2c_driver(lm73_driver); 287 288 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 289 MODULE_DESCRIPTION("LM73 driver"); 290 MODULE_LICENSE("GPL"); 291