1 /* 2 * Driver for Linear Technology LTC2990 power monitor 3 * 4 * Copyright (C) 2014 Topic Embedded Products 5 * Author: Mike Looijmans <mike.looijmans@topic.nl> 6 * 7 * License: GPLv2 8 */ 9 10 #include <linux/bitops.h> 11 #include <linux/err.h> 12 #include <linux/hwmon.h> 13 #include <linux/hwmon-sysfs.h> 14 #include <linux/i2c.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 19 #define LTC2990_STATUS 0x00 20 #define LTC2990_CONTROL 0x01 21 #define LTC2990_TRIGGER 0x02 22 #define LTC2990_TINT_MSB 0x04 23 #define LTC2990_V1_MSB 0x06 24 #define LTC2990_V2_MSB 0x08 25 #define LTC2990_V3_MSB 0x0A 26 #define LTC2990_V4_MSB 0x0C 27 #define LTC2990_VCC_MSB 0x0E 28 29 #define LTC2990_IN0 BIT(0) 30 #define LTC2990_IN1 BIT(1) 31 #define LTC2990_IN2 BIT(2) 32 #define LTC2990_IN3 BIT(3) 33 #define LTC2990_IN4 BIT(4) 34 #define LTC2990_CURR1 BIT(5) 35 #define LTC2990_CURR2 BIT(6) 36 #define LTC2990_TEMP1 BIT(7) 37 #define LTC2990_TEMP2 BIT(8) 38 #define LTC2990_TEMP3 BIT(9) 39 #define LTC2990_NONE 0 40 #define LTC2990_ALL GENMASK(9, 0) 41 42 #define LTC2990_MODE0_SHIFT 0 43 #define LTC2990_MODE0_MASK GENMASK(2, 0) 44 #define LTC2990_MODE1_SHIFT 3 45 #define LTC2990_MODE1_MASK GENMASK(1, 0) 46 47 /* Enabled measurements for mode bits 2..0 */ 48 static const int ltc2990_attrs_ena_0[] = { 49 LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3, 50 LTC2990_CURR1 | LTC2990_TEMP3, 51 LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4, 52 LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4, 53 LTC2990_TEMP2 | LTC2990_CURR2, 54 LTC2990_TEMP2 | LTC2990_TEMP3, 55 LTC2990_CURR1 | LTC2990_CURR2, 56 LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4 57 }; 58 59 /* Enabled measurements for mode bits 4..3 */ 60 static const int ltc2990_attrs_ena_1[] = { 61 LTC2990_NONE, 62 LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1, 63 LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2, 64 LTC2990_ALL 65 }; 66 67 struct ltc2990_data { 68 struct i2c_client *i2c; 69 u32 mode[2]; 70 }; 71 72 /* Return the converted value from the given register in uV or mC */ 73 static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result) 74 { 75 int val; 76 u8 reg; 77 78 switch (index) { 79 case LTC2990_IN0: 80 reg = LTC2990_VCC_MSB; 81 break; 82 case LTC2990_IN1: 83 case LTC2990_CURR1: 84 case LTC2990_TEMP2: 85 reg = LTC2990_V1_MSB; 86 break; 87 case LTC2990_IN2: 88 reg = LTC2990_V2_MSB; 89 break; 90 case LTC2990_IN3: 91 case LTC2990_CURR2: 92 case LTC2990_TEMP3: 93 reg = LTC2990_V3_MSB; 94 break; 95 case LTC2990_IN4: 96 reg = LTC2990_V4_MSB; 97 break; 98 case LTC2990_TEMP1: 99 reg = LTC2990_TINT_MSB; 100 break; 101 default: 102 return -EINVAL; 103 } 104 105 val = i2c_smbus_read_word_swapped(i2c, reg); 106 if (unlikely(val < 0)) 107 return val; 108 109 switch (index) { 110 case LTC2990_TEMP1: 111 case LTC2990_TEMP2: 112 case LTC2990_TEMP3: 113 /* temp, 0.0625 degrees/LSB */ 114 *result = sign_extend32(val, 12) * 1000 / 16; 115 break; 116 case LTC2990_CURR1: 117 case LTC2990_CURR2: 118 /* Vx-Vy, 19.42uV/LSB */ 119 *result = sign_extend32(val, 14) * 1942 / 100; 120 break; 121 case LTC2990_IN0: 122 /* Vcc, 305.18uV/LSB, 2.5V offset */ 123 *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500; 124 break; 125 case LTC2990_IN1: 126 case LTC2990_IN2: 127 case LTC2990_IN3: 128 case LTC2990_IN4: 129 /* Vx, 305.18uV/LSB */ 130 *result = sign_extend32(val, 14) * 30518 / (100 * 1000); 131 break; 132 default: 133 return -EINVAL; /* won't happen, keep compiler happy */ 134 } 135 136 return 0; 137 } 138 139 static ssize_t ltc2990_value_show(struct device *dev, 140 struct device_attribute *da, char *buf) 141 { 142 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 143 struct ltc2990_data *data = dev_get_drvdata(dev); 144 int value; 145 int ret; 146 147 ret = ltc2990_get_value(data->i2c, attr->index, &value); 148 if (unlikely(ret < 0)) 149 return ret; 150 151 return snprintf(buf, PAGE_SIZE, "%d\n", value); 152 } 153 154 static umode_t ltc2990_attrs_visible(struct kobject *kobj, 155 struct attribute *a, int n) 156 { 157 struct device *dev = container_of(kobj, struct device, kobj); 158 struct ltc2990_data *data = dev_get_drvdata(dev); 159 struct device_attribute *da = 160 container_of(a, struct device_attribute, attr); 161 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 162 163 int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 | 164 (ltc2990_attrs_ena_0[data->mode[0]] & 165 ltc2990_attrs_ena_1[data->mode[1]]); 166 167 if (attr->index & attrs_mask) 168 return a->mode; 169 170 return 0; 171 } 172 173 static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1); 174 static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2); 175 static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3); 176 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1); 177 static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2); 178 static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0); 179 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1); 180 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2); 181 static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3); 182 static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4); 183 184 static struct attribute *ltc2990_attrs[] = { 185 &sensor_dev_attr_temp1_input.dev_attr.attr, 186 &sensor_dev_attr_temp2_input.dev_attr.attr, 187 &sensor_dev_attr_temp3_input.dev_attr.attr, 188 &sensor_dev_attr_curr1_input.dev_attr.attr, 189 &sensor_dev_attr_curr2_input.dev_attr.attr, 190 &sensor_dev_attr_in0_input.dev_attr.attr, 191 &sensor_dev_attr_in1_input.dev_attr.attr, 192 &sensor_dev_attr_in2_input.dev_attr.attr, 193 &sensor_dev_attr_in3_input.dev_attr.attr, 194 &sensor_dev_attr_in4_input.dev_attr.attr, 195 NULL, 196 }; 197 198 static const struct attribute_group ltc2990_group = { 199 .attrs = ltc2990_attrs, 200 .is_visible = ltc2990_attrs_visible, 201 }; 202 __ATTRIBUTE_GROUPS(ltc2990); 203 204 static int ltc2990_i2c_probe(struct i2c_client *i2c, 205 const struct i2c_device_id *id) 206 { 207 int ret; 208 struct device *hwmon_dev; 209 struct ltc2990_data *data; 210 struct device_node *of_node = i2c->dev.of_node; 211 212 if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA | 213 I2C_FUNC_SMBUS_WORD_DATA)) 214 return -ENODEV; 215 216 data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL); 217 if (unlikely(!data)) 218 return -ENOMEM; 219 220 data->i2c = i2c; 221 222 if (of_node) { 223 ret = of_property_read_u32_array(of_node, "lltc,meas-mode", 224 data->mode, 2); 225 if (ret < 0) 226 return ret; 227 228 if (data->mode[0] & ~LTC2990_MODE0_MASK || 229 data->mode[1] & ~LTC2990_MODE1_MASK) 230 return -EINVAL; 231 } else { 232 ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL); 233 if (ret < 0) 234 return ret; 235 236 data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK; 237 data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK; 238 } 239 240 /* Setup continuous mode */ 241 ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL, 242 data->mode[0] << LTC2990_MODE0_SHIFT | 243 data->mode[1] << LTC2990_MODE1_SHIFT); 244 if (ret < 0) { 245 dev_err(&i2c->dev, "Error: Failed to set control mode.\n"); 246 return ret; 247 } 248 /* Trigger once to start continuous conversion */ 249 ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1); 250 if (ret < 0) { 251 dev_err(&i2c->dev, "Error: Failed to start acquisition.\n"); 252 return ret; 253 } 254 255 hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev, 256 i2c->name, 257 data, 258 ltc2990_groups); 259 260 return PTR_ERR_OR_ZERO(hwmon_dev); 261 } 262 263 static const struct i2c_device_id ltc2990_i2c_id[] = { 264 { "ltc2990", 0 }, 265 {} 266 }; 267 MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id); 268 269 static struct i2c_driver ltc2990_i2c_driver = { 270 .driver = { 271 .name = "ltc2990", 272 }, 273 .probe = ltc2990_i2c_probe, 274 .id_table = ltc2990_i2c_id, 275 }; 276 277 module_i2c_driver(ltc2990_i2c_driver); 278 279 MODULE_DESCRIPTION("LTC2990 Sensor Driver"); 280 MODULE_AUTHOR("Topic Embedded Products"); 281 MODULE_LICENSE("GPL v2"); 282