1 /* 2 * Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor) 3 * 4 * Copyright (C) 2008, 2010 Pengutronix 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * TODO: SPI, support for external temperature sensor 11 * use power-down mode for suspend?, interrupt handling? 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/err.h> 18 #include <linux/mutex.h> 19 #include <linux/jiffies.h> 20 #include <linux/i2c.h> 21 #include <linux/hwmon.h> 22 #include <linux/hwmon-sysfs.h> 23 #include <linux/slab.h> 24 25 #define ADT7411_REG_INT_TEMP_VDD_LSB 0x03 26 #define ADT7411_REG_EXT_TEMP_AIN14_LSB 0x04 27 #define ADT7411_REG_VDD_MSB 0x06 28 #define ADT7411_REG_INT_TEMP_MSB 0x07 29 #define ADT7411_REG_EXT_TEMP_AIN1_MSB 0x08 30 31 #define ADT7411_REG_CFG1 0x18 32 #define ADT7411_CFG1_START_MONITOR (1 << 0) 33 34 #define ADT7411_REG_CFG2 0x19 35 #define ADT7411_CFG2_DISABLE_AVG (1 << 5) 36 37 #define ADT7411_REG_CFG3 0x1a 38 #define ADT7411_CFG3_ADC_CLK_225 (1 << 0) 39 #define ADT7411_CFG3_REF_VDD (1 << 4) 40 41 #define ADT7411_REG_DEVICE_ID 0x4d 42 #define ADT7411_REG_MANUFACTURER_ID 0x4e 43 44 #define ADT7411_DEVICE_ID 0x2 45 #define ADT7411_MANUFACTURER_ID 0x41 46 47 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END }; 48 49 struct adt7411_data { 50 struct mutex device_lock; /* for "atomic" device accesses */ 51 struct mutex update_lock; 52 unsigned long next_update; 53 int vref_cached; 54 struct device *hwmon_dev; 55 }; 56 57 /* 58 * When reading a register containing (up to 4) lsb, all associated 59 * msb-registers get locked by the hardware. After _one_ of those msb is read, 60 * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb 61 * is protected here with a mutex, too. 62 */ 63 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg, 64 u8 msb_reg, u8 lsb_shift) 65 { 66 struct adt7411_data *data = i2c_get_clientdata(client); 67 int val, tmp; 68 69 mutex_lock(&data->device_lock); 70 71 val = i2c_smbus_read_byte_data(client, lsb_reg); 72 if (val < 0) 73 goto exit_unlock; 74 75 tmp = (val >> lsb_shift) & 3; 76 val = i2c_smbus_read_byte_data(client, msb_reg); 77 78 if (val >= 0) 79 val = (val << 2) | tmp; 80 81 exit_unlock: 82 mutex_unlock(&data->device_lock); 83 84 return val; 85 } 86 87 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit, 88 bool flag) 89 { 90 struct adt7411_data *data = i2c_get_clientdata(client); 91 int ret, val; 92 93 mutex_lock(&data->device_lock); 94 95 ret = i2c_smbus_read_byte_data(client, reg); 96 if (ret < 0) 97 goto exit_unlock; 98 99 if (flag) 100 val = ret | bit; 101 else 102 val = ret & ~bit; 103 104 ret = i2c_smbus_write_byte_data(client, reg, val); 105 106 exit_unlock: 107 mutex_unlock(&data->device_lock); 108 return ret; 109 } 110 111 static ssize_t adt7411_show_vdd(struct device *dev, 112 struct device_attribute *attr, char *buf) 113 { 114 struct i2c_client *client = to_i2c_client(dev); 115 int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB, 116 ADT7411_REG_VDD_MSB, 2); 117 118 return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024); 119 } 120 121 static ssize_t adt7411_show_temp(struct device *dev, 122 struct device_attribute *attr, char *buf) 123 { 124 struct i2c_client *client = to_i2c_client(dev); 125 int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB, 126 ADT7411_REG_INT_TEMP_MSB, 0); 127 128 if (val < 0) 129 return val; 130 131 val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */ 132 133 return sprintf(buf, "%d\n", val * 250); 134 } 135 136 static ssize_t adt7411_show_input(struct device *dev, 137 struct device_attribute *attr, char *buf) 138 { 139 int nr = to_sensor_dev_attr(attr)->index; 140 struct i2c_client *client = to_i2c_client(dev); 141 struct adt7411_data *data = i2c_get_clientdata(client); 142 int val; 143 u8 lsb_reg, lsb_shift; 144 145 mutex_lock(&data->update_lock); 146 if (time_after_eq(jiffies, data->next_update)) { 147 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3); 148 if (val < 0) 149 goto exit_unlock; 150 151 if (val & ADT7411_CFG3_REF_VDD) { 152 val = adt7411_read_10_bit(client, 153 ADT7411_REG_INT_TEMP_VDD_LSB, 154 ADT7411_REG_VDD_MSB, 2); 155 if (val < 0) 156 goto exit_unlock; 157 158 data->vref_cached = val * 7000 / 1024; 159 } else { 160 data->vref_cached = 2250; 161 } 162 163 data->next_update = jiffies + HZ; 164 } 165 166 lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2); 167 lsb_shift = 2 * (nr & 0x03); 168 val = adt7411_read_10_bit(client, lsb_reg, 169 ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift); 170 if (val < 0) 171 goto exit_unlock; 172 173 val = sprintf(buf, "%u\n", val * data->vref_cached / 1024); 174 exit_unlock: 175 mutex_unlock(&data->update_lock); 176 return val; 177 } 178 179 static ssize_t adt7411_show_bit(struct device *dev, 180 struct device_attribute *attr, char *buf) 181 { 182 struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); 183 struct i2c_client *client = to_i2c_client(dev); 184 int ret = i2c_smbus_read_byte_data(client, attr2->index); 185 186 return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr)); 187 } 188 189 static ssize_t adt7411_set_bit(struct device *dev, 190 struct device_attribute *attr, const char *buf, 191 size_t count) 192 { 193 struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr); 194 struct i2c_client *client = to_i2c_client(dev); 195 struct adt7411_data *data = i2c_get_clientdata(client); 196 int ret; 197 unsigned long flag; 198 199 ret = kstrtoul(buf, 0, &flag); 200 if (ret || flag > 1) 201 return -EINVAL; 202 203 ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag); 204 205 /* force update */ 206 mutex_lock(&data->update_lock); 207 data->next_update = jiffies; 208 mutex_unlock(&data->update_lock); 209 210 return ret < 0 ? ret : count; 211 } 212 213 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \ 214 SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \ 215 adt7411_set_bit, __bit, __reg) 216 217 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL); 218 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL); 219 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0); 220 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1); 221 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2); 222 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3); 223 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4); 224 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5); 225 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6); 226 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7); 227 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG); 228 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225); 229 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD); 230 231 static struct attribute *adt7411_attrs[] = { 232 &dev_attr_temp1_input.attr, 233 &dev_attr_in0_input.attr, 234 &sensor_dev_attr_in1_input.dev_attr.attr, 235 &sensor_dev_attr_in2_input.dev_attr.attr, 236 &sensor_dev_attr_in3_input.dev_attr.attr, 237 &sensor_dev_attr_in4_input.dev_attr.attr, 238 &sensor_dev_attr_in5_input.dev_attr.attr, 239 &sensor_dev_attr_in6_input.dev_attr.attr, 240 &sensor_dev_attr_in7_input.dev_attr.attr, 241 &sensor_dev_attr_in8_input.dev_attr.attr, 242 &sensor_dev_attr_no_average.dev_attr.attr, 243 &sensor_dev_attr_fast_sampling.dev_attr.attr, 244 &sensor_dev_attr_adc_ref_vdd.dev_attr.attr, 245 NULL 246 }; 247 248 static const struct attribute_group adt7411_attr_grp = { 249 .attrs = adt7411_attrs, 250 }; 251 252 static int adt7411_detect(struct i2c_client *client, 253 struct i2c_board_info *info) 254 { 255 int val; 256 257 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 258 return -ENODEV; 259 260 val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID); 261 if (val < 0 || val != ADT7411_MANUFACTURER_ID) { 262 dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, " 263 "expected %d\n", val, ADT7411_MANUFACTURER_ID); 264 return -ENODEV; 265 } 266 267 val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID); 268 if (val < 0 || val != ADT7411_DEVICE_ID) { 269 dev_dbg(&client->dev, "Wrong device ID. Got %d, " 270 "expected %d\n", val, ADT7411_DEVICE_ID); 271 return -ENODEV; 272 } 273 274 strlcpy(info->type, "adt7411", I2C_NAME_SIZE); 275 276 return 0; 277 } 278 279 static int adt7411_probe(struct i2c_client *client, 280 const struct i2c_device_id *id) 281 { 282 struct adt7411_data *data; 283 int ret; 284 285 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); 286 if (!data) 287 return -ENOMEM; 288 289 i2c_set_clientdata(client, data); 290 mutex_init(&data->device_lock); 291 mutex_init(&data->update_lock); 292 293 ret = adt7411_modify_bit(client, ADT7411_REG_CFG1, 294 ADT7411_CFG1_START_MONITOR, 1); 295 if (ret < 0) 296 return ret; 297 298 /* force update on first occasion */ 299 data->next_update = jiffies; 300 301 ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp); 302 if (ret) 303 return ret; 304 305 data->hwmon_dev = hwmon_device_register(&client->dev); 306 if (IS_ERR(data->hwmon_dev)) { 307 ret = PTR_ERR(data->hwmon_dev); 308 goto exit_remove; 309 } 310 311 dev_info(&client->dev, "successfully registered\n"); 312 313 return 0; 314 315 exit_remove: 316 sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp); 317 return ret; 318 } 319 320 static int adt7411_remove(struct i2c_client *client) 321 { 322 struct adt7411_data *data = i2c_get_clientdata(client); 323 324 hwmon_device_unregister(data->hwmon_dev); 325 sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp); 326 return 0; 327 } 328 329 static const struct i2c_device_id adt7411_id[] = { 330 { "adt7411", 0 }, 331 { } 332 }; 333 MODULE_DEVICE_TABLE(i2c, adt7411_id); 334 335 static struct i2c_driver adt7411_driver = { 336 .driver = { 337 .name = "adt7411", 338 }, 339 .probe = adt7411_probe, 340 .remove = adt7411_remove, 341 .id_table = adt7411_id, 342 .detect = adt7411_detect, 343 .address_list = normal_i2c, 344 .class = I2C_CLASS_HWMON, 345 }; 346 347 module_i2c_driver(adt7411_driver); 348 349 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and " 350 "Wolfram Sang <w.sang@pengutronix.de>"); 351 MODULE_DESCRIPTION("ADT7411 driver"); 352 MODULE_LICENSE("GPL v2"); 353