1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ds620.c - Support for temperature sensor and thermostat DS620 4 * 5 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> 6 * 7 * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/init.h> 12 #include <linux/slab.h> 13 #include <linux/jiffies.h> 14 #include <linux/i2c.h> 15 #include <linux/hwmon.h> 16 #include <linux/hwmon-sysfs.h> 17 #include <linux/err.h> 18 #include <linux/mutex.h> 19 #include <linux/sysfs.h> 20 #include <linux/platform_data/ds620.h> 21 22 /* 23 * Many DS620 constants specified below 24 * 15 14 13 12 11 10 09 08 25 * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT| 26 * 27 * 07 06 05 04 03 02 01 00 28 * |PO2 |PO1 |A2 |A1 |A0 | | | | 29 */ 30 #define DS620_REG_CONFIG_DONE 0x8000 31 #define DS620_REG_CONFIG_NVB 0x4000 32 #define DS620_REG_CONFIG_THF 0x2000 33 #define DS620_REG_CONFIG_TLF 0x1000 34 #define DS620_REG_CONFIG_R1 0x0800 35 #define DS620_REG_CONFIG_R0 0x0400 36 #define DS620_REG_CONFIG_AUTOC 0x0200 37 #define DS620_REG_CONFIG_1SHOT 0x0100 38 #define DS620_REG_CONFIG_PO2 0x0080 39 #define DS620_REG_CONFIG_PO1 0x0040 40 #define DS620_REG_CONFIG_A2 0x0020 41 #define DS620_REG_CONFIG_A1 0x0010 42 #define DS620_REG_CONFIG_A0 0x0008 43 44 /* The DS620 registers */ 45 static const u8 DS620_REG_TEMP[3] = { 46 0xAA, /* input, word, RO */ 47 0xA2, /* min, word, RW */ 48 0xA0, /* max, word, RW */ 49 }; 50 51 #define DS620_REG_CONF 0xAC /* word, RW */ 52 #define DS620_COM_START 0x51 /* no data */ 53 #define DS620_COM_STOP 0x22 /* no data */ 54 55 /* Each client has this additional data */ 56 struct ds620_data { 57 struct i2c_client *client; 58 struct mutex update_lock; 59 bool valid; /* true if following fields are valid */ 60 unsigned long last_updated; /* In jiffies */ 61 62 s16 temp[3]; /* Register values, word */ 63 }; 64 65 static void ds620_init_client(struct i2c_client *client) 66 { 67 struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev); 68 u16 conf, new_conf; 69 70 new_conf = conf = 71 i2c_smbus_read_word_swapped(client, DS620_REG_CONF); 72 73 /* switch to continuous conversion mode */ 74 new_conf &= ~DS620_REG_CONFIG_1SHOT; 75 /* already high at power-on, but don't trust the BIOS! */ 76 new_conf |= DS620_REG_CONFIG_PO2; 77 /* thermostat mode according to platform data */ 78 if (ds620_info && ds620_info->pomode == 1) 79 new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */ 80 else if (ds620_info && ds620_info->pomode == 2) 81 new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */ 82 else 83 new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */ 84 /* with highest precision */ 85 new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0; 86 87 if (conf != new_conf) 88 i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf); 89 90 /* start conversion */ 91 i2c_smbus_write_byte(client, DS620_COM_START); 92 } 93 94 static struct ds620_data *ds620_update_client(struct device *dev) 95 { 96 struct ds620_data *data = dev_get_drvdata(dev); 97 struct i2c_client *client = data->client; 98 struct ds620_data *ret = data; 99 100 mutex_lock(&data->update_lock); 101 102 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 103 || !data->valid) { 104 int i; 105 int res; 106 107 dev_dbg(&client->dev, "Starting ds620 update\n"); 108 109 for (i = 0; i < ARRAY_SIZE(data->temp); i++) { 110 res = i2c_smbus_read_word_swapped(client, 111 DS620_REG_TEMP[i]); 112 if (res < 0) { 113 ret = ERR_PTR(res); 114 goto abort; 115 } 116 117 data->temp[i] = res; 118 } 119 120 data->last_updated = jiffies; 121 data->valid = true; 122 } 123 abort: 124 mutex_unlock(&data->update_lock); 125 126 return ret; 127 } 128 129 static ssize_t temp_show(struct device *dev, struct device_attribute *da, 130 char *buf) 131 { 132 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 133 struct ds620_data *data = ds620_update_client(dev); 134 135 if (IS_ERR(data)) 136 return PTR_ERR(data); 137 138 return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10); 139 } 140 141 static ssize_t temp_store(struct device *dev, struct device_attribute *da, 142 const char *buf, size_t count) 143 { 144 int res; 145 long val; 146 147 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 148 struct ds620_data *data = dev_get_drvdata(dev); 149 struct i2c_client *client = data->client; 150 151 res = kstrtol(buf, 10, &val); 152 153 if (res) 154 return res; 155 156 val = (clamp_val(val, -128000, 128000) * 10 / 625) * 8; 157 158 mutex_lock(&data->update_lock); 159 data->temp[attr->index] = val; 160 i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index], 161 data->temp[attr->index]); 162 mutex_unlock(&data->update_lock); 163 return count; 164 } 165 166 static ssize_t alarm_show(struct device *dev, struct device_attribute *da, 167 char *buf) 168 { 169 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 170 struct ds620_data *data = ds620_update_client(dev); 171 struct i2c_client *client; 172 u16 conf, new_conf; 173 int res; 174 175 if (IS_ERR(data)) 176 return PTR_ERR(data); 177 178 client = data->client; 179 180 /* reset alarms if necessary */ 181 res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF); 182 if (res < 0) 183 return res; 184 185 new_conf = conf = res; 186 new_conf &= ~attr->index; 187 if (conf != new_conf) { 188 res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF, 189 new_conf); 190 if (res < 0) 191 return res; 192 } 193 194 return sprintf(buf, "%d\n", !!(conf & attr->index)); 195 } 196 197 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0); 198 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1); 199 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2); 200 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS620_REG_CONFIG_TLF); 201 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS620_REG_CONFIG_THF); 202 203 static struct attribute *ds620_attrs[] = { 204 &sensor_dev_attr_temp1_input.dev_attr.attr, 205 &sensor_dev_attr_temp1_min.dev_attr.attr, 206 &sensor_dev_attr_temp1_max.dev_attr.attr, 207 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 208 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 209 NULL 210 }; 211 212 ATTRIBUTE_GROUPS(ds620); 213 214 static int ds620_probe(struct i2c_client *client) 215 { 216 struct device *dev = &client->dev; 217 struct device *hwmon_dev; 218 struct ds620_data *data; 219 220 data = devm_kzalloc(dev, sizeof(struct ds620_data), GFP_KERNEL); 221 if (!data) 222 return -ENOMEM; 223 224 data->client = client; 225 mutex_init(&data->update_lock); 226 227 /* Initialize the DS620 chip */ 228 ds620_init_client(client); 229 230 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 231 data, ds620_groups); 232 return PTR_ERR_OR_ZERO(hwmon_dev); 233 } 234 235 static const struct i2c_device_id ds620_id[] = { 236 {"ds620"}, 237 {} 238 }; 239 240 MODULE_DEVICE_TABLE(i2c, ds620_id); 241 242 /* This is the driver that will be inserted */ 243 static struct i2c_driver ds620_driver = { 244 .driver = { 245 .name = "ds620", 246 }, 247 .probe = ds620_probe, 248 .id_table = ds620_id, 249 }; 250 251 module_i2c_driver(ds620_driver); 252 253 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); 254 MODULE_DESCRIPTION("DS620 driver"); 255 MODULE_LICENSE("GPL"); 256