1 /* 2 * ds620.c - Support for temperature sensor and thermostat DS620 3 * 4 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> 5 * 6 * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net> 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 as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 */ 22 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/slab.h> 26 #include <linux/jiffies.h> 27 #include <linux/i2c.h> 28 #include <linux/hwmon.h> 29 #include <linux/hwmon-sysfs.h> 30 #include <linux/err.h> 31 #include <linux/mutex.h> 32 #include <linux/sysfs.h> 33 #include <linux/i2c/ds620.h> 34 35 /* 36 * Many DS620 constants specified below 37 * 15 14 13 12 11 10 09 08 38 * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT| 39 * 40 * 07 06 05 04 03 02 01 00 41 * |PO2 |PO1 |A2 |A1 |A0 | | | | 42 */ 43 #define DS620_REG_CONFIG_DONE 0x8000 44 #define DS620_REG_CONFIG_NVB 0x4000 45 #define DS620_REG_CONFIG_THF 0x2000 46 #define DS620_REG_CONFIG_TLF 0x1000 47 #define DS620_REG_CONFIG_R1 0x0800 48 #define DS620_REG_CONFIG_R0 0x0400 49 #define DS620_REG_CONFIG_AUTOC 0x0200 50 #define DS620_REG_CONFIG_1SHOT 0x0100 51 #define DS620_REG_CONFIG_PO2 0x0080 52 #define DS620_REG_CONFIG_PO1 0x0040 53 #define DS620_REG_CONFIG_A2 0x0020 54 #define DS620_REG_CONFIG_A1 0x0010 55 #define DS620_REG_CONFIG_A0 0x0008 56 57 /* The DS620 registers */ 58 static const u8 DS620_REG_TEMP[3] = { 59 0xAA, /* input, word, RO */ 60 0xA2, /* min, word, RW */ 61 0xA0, /* max, word, RW */ 62 }; 63 64 #define DS620_REG_CONF 0xAC /* word, RW */ 65 #define DS620_COM_START 0x51 /* no data */ 66 #define DS620_COM_STOP 0x22 /* no data */ 67 68 /* Each client has this additional data */ 69 struct ds620_data { 70 struct i2c_client *client; 71 struct mutex update_lock; 72 char valid; /* !=0 if following fields are valid */ 73 unsigned long last_updated; /* In jiffies */ 74 75 s16 temp[3]; /* Register values, word */ 76 }; 77 78 static void ds620_init_client(struct i2c_client *client) 79 { 80 struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev); 81 u16 conf, new_conf; 82 83 new_conf = conf = 84 i2c_smbus_read_word_swapped(client, DS620_REG_CONF); 85 86 /* switch to continuous conversion mode */ 87 new_conf &= ~DS620_REG_CONFIG_1SHOT; 88 /* already high at power-on, but don't trust the BIOS! */ 89 new_conf |= DS620_REG_CONFIG_PO2; 90 /* thermostat mode according to platform data */ 91 if (ds620_info && ds620_info->pomode == 1) 92 new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */ 93 else if (ds620_info && ds620_info->pomode == 2) 94 new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */ 95 else 96 new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */ 97 /* with highest precision */ 98 new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0; 99 100 if (conf != new_conf) 101 i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf); 102 103 /* start conversion */ 104 i2c_smbus_write_byte(client, DS620_COM_START); 105 } 106 107 static struct ds620_data *ds620_update_client(struct device *dev) 108 { 109 struct ds620_data *data = dev_get_drvdata(dev); 110 struct i2c_client *client = data->client; 111 struct ds620_data *ret = data; 112 113 mutex_lock(&data->update_lock); 114 115 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 116 || !data->valid) { 117 int i; 118 int res; 119 120 dev_dbg(&client->dev, "Starting ds620 update\n"); 121 122 for (i = 0; i < ARRAY_SIZE(data->temp); i++) { 123 res = i2c_smbus_read_word_swapped(client, 124 DS620_REG_TEMP[i]); 125 if (res < 0) { 126 ret = ERR_PTR(res); 127 goto abort; 128 } 129 130 data->temp[i] = res; 131 } 132 133 data->last_updated = jiffies; 134 data->valid = 1; 135 } 136 abort: 137 mutex_unlock(&data->update_lock); 138 139 return ret; 140 } 141 142 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 143 char *buf) 144 { 145 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 146 struct ds620_data *data = ds620_update_client(dev); 147 148 if (IS_ERR(data)) 149 return PTR_ERR(data); 150 151 return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10); 152 } 153 154 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 155 const char *buf, size_t count) 156 { 157 int res; 158 long val; 159 160 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 161 struct ds620_data *data = dev_get_drvdata(dev); 162 struct i2c_client *client = data->client; 163 164 res = kstrtol(buf, 10, &val); 165 166 if (res) 167 return res; 168 169 val = (val * 10 / 625) * 8; 170 171 mutex_lock(&data->update_lock); 172 data->temp[attr->index] = val; 173 i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index], 174 data->temp[attr->index]); 175 mutex_unlock(&data->update_lock); 176 return count; 177 } 178 179 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 180 char *buf) 181 { 182 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 183 struct ds620_data *data = ds620_update_client(dev); 184 struct i2c_client *client; 185 u16 conf, new_conf; 186 int res; 187 188 if (IS_ERR(data)) 189 return PTR_ERR(data); 190 191 client = data->client; 192 193 /* reset alarms if necessary */ 194 res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF); 195 if (res < 0) 196 return res; 197 198 new_conf = conf = res; 199 new_conf &= ~attr->index; 200 if (conf != new_conf) { 201 res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF, 202 new_conf); 203 if (res < 0) 204 return res; 205 } 206 207 return sprintf(buf, "%d\n", !!(conf & attr->index)); 208 } 209 210 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 211 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 212 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 213 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 214 DS620_REG_CONFIG_TLF); 215 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 216 DS620_REG_CONFIG_THF); 217 218 static struct attribute *ds620_attrs[] = { 219 &sensor_dev_attr_temp1_input.dev_attr.attr, 220 &sensor_dev_attr_temp1_min.dev_attr.attr, 221 &sensor_dev_attr_temp1_max.dev_attr.attr, 222 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 223 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 224 NULL 225 }; 226 227 ATTRIBUTE_GROUPS(ds620); 228 229 static int ds620_probe(struct i2c_client *client, 230 const struct i2c_device_id *id) 231 { 232 struct device *dev = &client->dev; 233 struct device *hwmon_dev; 234 struct ds620_data *data; 235 236 data = devm_kzalloc(dev, sizeof(struct ds620_data), GFP_KERNEL); 237 if (!data) 238 return -ENOMEM; 239 240 data->client = client; 241 mutex_init(&data->update_lock); 242 243 /* Initialize the DS620 chip */ 244 ds620_init_client(client); 245 246 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 247 data, ds620_groups); 248 return PTR_ERR_OR_ZERO(hwmon_dev); 249 } 250 251 static const struct i2c_device_id ds620_id[] = { 252 {"ds620", 0}, 253 {} 254 }; 255 256 MODULE_DEVICE_TABLE(i2c, ds620_id); 257 258 /* This is the driver that will be inserted */ 259 static struct i2c_driver ds620_driver = { 260 .class = I2C_CLASS_HWMON, 261 .driver = { 262 .name = "ds620", 263 }, 264 .probe = ds620_probe, 265 .id_table = ds620_id, 266 }; 267 268 module_i2c_driver(ds620_driver); 269 270 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); 271 MODULE_DESCRIPTION("DS620 driver"); 272 MODULE_LICENSE("GPL"); 273