drivers/hwmon/powr1220.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * powr1220.c - Driver for the Lattice POWR1220 programmable power supply
   4  * and monitor. Users can read all ADC inputs along with their labels
   5  * using the sysfs nodes.
   6  *
   7  * Copyright (c) 2014 Echo360 https://www.echo360.com
   8  * Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/slab.h>
  14 #include <linux/jiffies.h>
  15 #include <linux/i2c.h>
  16 #include <linux/hwmon.h>
  17 #include <linux/hwmon-sysfs.h>
  18 #include <linux/err.h>
  19 #include <linux/mutex.h>
  20 #include <linux/delay.h>
  21
  22 #define ADC_STEP_MV                     2
  23 #define ADC_MAX_LOW_MEASUREMENT_MV      2000
  24
  25 enum powr1220_regs {
  26         VMON_STATUS0,
  27         VMON_STATUS1,
  28         VMON_STATUS2,
  29         OUTPUT_STATUS0,
  30         OUTPUT_STATUS1,
  31         OUTPUT_STATUS2,
  32         INPUT_STATUS,
  33         ADC_VALUE_LOW,
  34         ADC_VALUE_HIGH,
  35         ADC_MUX,
  36         UES_BYTE0,
  37         UES_BYTE1,
  38         UES_BYTE2,
  39         UES_BYTE3,
  40         GP_OUTPUT1,
  41         GP_OUTPUT2,
  42         GP_OUTPUT3,
  43         INPUT_VALUE,
  44         RESET,
  45         TRIM1_TRIM,
  46         TRIM2_TRIM,
  47         TRIM3_TRIM,
  48         TRIM4_TRIM,
  49         TRIM5_TRIM,
  50         TRIM6_TRIM,
  51         TRIM7_TRIM,
  52         TRIM8_TRIM,
  53         MAX_POWR1220_REGS
  54 };
  55
  56 enum powr1220_adc_values {
  57         VMON1,
  58         VMON2,
  59         VMON3,
  60         VMON4,
  61         VMON5,
  62         VMON6,
  63         VMON7,
  64         VMON8,
  65         VMON9,
  66         VMON10,
  67         VMON11,
  68         VMON12,
  69         VCCA,
  70         VCCINP,
  71         MAX_POWR1220_ADC_VALUES
  72 };
  73
  74 struct powr1220_data {
  75         struct i2c_client *client;
  76         struct mutex update_lock;
  77         bool adc_valid[MAX_POWR1220_ADC_VALUES];
  78          /* the next value is in jiffies */
  79         unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
  80
  81         /* values */
  82         int adc_maxes[MAX_POWR1220_ADC_VALUES];
  83         int adc_values[MAX_POWR1220_ADC_VALUES];
  84 };
  85
  86 static const char * const input_names[] = {
  87         [VMON1]    = "vmon1",
  88         [VMON2]    = "vmon2",
  89         [VMON3]    = "vmon3",
  90         [VMON4]    = "vmon4",
  91         [VMON5]    = "vmon5",
  92         [VMON6]    = "vmon6",
  93         [VMON7]    = "vmon7",
  94         [VMON8]    = "vmon8",
  95         [VMON9]    = "vmon9",
  96         [VMON10]   = "vmon10",
  97         [VMON11]   = "vmon11",
  98         [VMON12]   = "vmon12",
  99         [VCCA]     = "vcca",
 100         [VCCINP]   = "vccinp",
 101 };
 102
 103 /* Reads the specified ADC channel */
 104 static int powr1220_read_adc(struct device *dev, int ch_num)
 105 {
 106         struct powr1220_data *data = dev_get_drvdata(dev);
 107         int reading;
 108         int result;
 109         int adc_range = 0;
 110
 111         mutex_lock(&data->update_lock);
 112
 113         if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
 114                         !data->adc_valid[ch_num]) {
 115                 /*
 116                  * figure out if we need to use the attenuator for
 117                  * high inputs or inputs that we don't yet have a measurement
 118                  * for. We dynamically set the attenuator depending on the
 119                  * max reading.
 120                  */
 121                 if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
 122                                 data->adc_maxes[ch_num] == 0)
 123                         adc_range = 1 << 4;
 124
 125                 /* set the attenuator and mux */
 126                 result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
 127                                 adc_range | ch_num);
 128                 if (result)
 129                         goto exit;
 130
 131                 /*
 132                  * wait at least Tconvert time (200 us) for the
 133                  * conversion to complete
 134                  */
 135                 udelay(200);
 136
 137                 /* get the ADC reading */
 138                 result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
 139                 if (result < 0)
 140                         goto exit;
 141
 142                 reading = result >> 4;
 143
 144                 /* get the upper half of the reading */
 145                 result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
 146                 if (result < 0)
 147                         goto exit;
 148
 149                 reading |= result << 4;
 150
 151                 /* now convert the reading to a voltage */
 152                 reading *= ADC_STEP_MV;
 153                 data->adc_values[ch_num] = reading;
 154                 data->adc_valid[ch_num] = true;
 155                 data->adc_last_updated[ch_num] = jiffies;
 156                 result = reading;
 157
 158                 if (reading > data->adc_maxes[ch_num])
 159                         data->adc_maxes[ch_num] = reading;
 160         } else {
 161                 result = data->adc_values[ch_num];
 162         }
 163
 164 exit:
 165         mutex_unlock(&data->update_lock);
 166
 167         return result;
 168 }
 169
 170 /* Shows the voltage associated with the specified ADC channel */
 171 static ssize_t powr1220_voltage_show(struct device *dev,
 172                                      struct device_attribute *dev_attr,
 173                                      char *buf)
 174 {
 175         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 176         int adc_val = powr1220_read_adc(dev, attr->index);
 177
 178         if (adc_val < 0)
 179                 return adc_val;
 180
 181         return sprintf(buf, "%d\n", adc_val);
 182 }
 183
 184 /* Shows the maximum setting associated with the specified ADC channel */
 185 static ssize_t powr1220_max_show(struct device *dev,
 186                                  struct device_attribute *dev_attr, char *buf)
 187 {
 188         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 189         struct powr1220_data *data = dev_get_drvdata(dev);
 190
 191         return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
 192 }
 193
 194 /* Shows the label associated with the specified ADC channel */
 195 static ssize_t powr1220_label_show(struct device *dev,
 196                                    struct device_attribute *dev_attr,
 197                                    char *buf)
 198 {
 199         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 200
 201         return sprintf(buf, "%s\n", input_names[attr->index]);
 202 }
 203
 204 static SENSOR_DEVICE_ATTR_RO(in0_input, powr1220_voltage, VMON1);
 205 static SENSOR_DEVICE_ATTR_RO(in1_input, powr1220_voltage, VMON2);
 206 static SENSOR_DEVICE_ATTR_RO(in2_input, powr1220_voltage, VMON3);
 207 static SENSOR_DEVICE_ATTR_RO(in3_input, powr1220_voltage, VMON4);
 208 static SENSOR_DEVICE_ATTR_RO(in4_input, powr1220_voltage, VMON5);
 209 static SENSOR_DEVICE_ATTR_RO(in5_input, powr1220_voltage, VMON6);
 210 static SENSOR_DEVICE_ATTR_RO(in6_input, powr1220_voltage, VMON7);
 211 static SENSOR_DEVICE_ATTR_RO(in7_input, powr1220_voltage, VMON8);
 212 static SENSOR_DEVICE_ATTR_RO(in8_input, powr1220_voltage, VMON9);
 213 static SENSOR_DEVICE_ATTR_RO(in9_input, powr1220_voltage, VMON10);
 214 static SENSOR_DEVICE_ATTR_RO(in10_input, powr1220_voltage, VMON11);
 215 static SENSOR_DEVICE_ATTR_RO(in11_input, powr1220_voltage, VMON12);
 216 static SENSOR_DEVICE_ATTR_RO(in12_input, powr1220_voltage, VCCA);
 217 static SENSOR_DEVICE_ATTR_RO(in13_input, powr1220_voltage, VCCINP);
 218
 219 static SENSOR_DEVICE_ATTR_RO(in0_highest, powr1220_max, VMON1);
 220 static SENSOR_DEVICE_ATTR_RO(in1_highest, powr1220_max, VMON2);
 221 static SENSOR_DEVICE_ATTR_RO(in2_highest, powr1220_max, VMON3);
 222 static SENSOR_DEVICE_ATTR_RO(in3_highest, powr1220_max, VMON4);
 223 static SENSOR_DEVICE_ATTR_RO(in4_highest, powr1220_max, VMON5);
 224 static SENSOR_DEVICE_ATTR_RO(in5_highest, powr1220_max, VMON6);
 225 static SENSOR_DEVICE_ATTR_RO(in6_highest, powr1220_max, VMON7);
 226 static SENSOR_DEVICE_ATTR_RO(in7_highest, powr1220_max, VMON8);
 227 static SENSOR_DEVICE_ATTR_RO(in8_highest, powr1220_max, VMON9);
 228 static SENSOR_DEVICE_ATTR_RO(in9_highest, powr1220_max, VMON10);
 229 static SENSOR_DEVICE_ATTR_RO(in10_highest, powr1220_max, VMON11);
 230 static SENSOR_DEVICE_ATTR_RO(in11_highest, powr1220_max, VMON12);
 231 static SENSOR_DEVICE_ATTR_RO(in12_highest, powr1220_max, VCCA);
 232 static SENSOR_DEVICE_ATTR_RO(in13_highest, powr1220_max, VCCINP);
 233
 234 static SENSOR_DEVICE_ATTR_RO(in0_label, powr1220_label, VMON1);
 235 static SENSOR_DEVICE_ATTR_RO(in1_label, powr1220_label, VMON2);
 236 static SENSOR_DEVICE_ATTR_RO(in2_label, powr1220_label, VMON3);
 237 static SENSOR_DEVICE_ATTR_RO(in3_label, powr1220_label, VMON4);
 238 static SENSOR_DEVICE_ATTR_RO(in4_label, powr1220_label, VMON5);
 239 static SENSOR_DEVICE_ATTR_RO(in5_label, powr1220_label, VMON6);
 240 static SENSOR_DEVICE_ATTR_RO(in6_label, powr1220_label, VMON7);
 241 static SENSOR_DEVICE_ATTR_RO(in7_label, powr1220_label, VMON8);
 242 static SENSOR_DEVICE_ATTR_RO(in8_label, powr1220_label, VMON9);
 243 static SENSOR_DEVICE_ATTR_RO(in9_label, powr1220_label, VMON10);
 244 static SENSOR_DEVICE_ATTR_RO(in10_label, powr1220_label, VMON11);
 245 static SENSOR_DEVICE_ATTR_RO(in11_label, powr1220_label, VMON12);
 246 static SENSOR_DEVICE_ATTR_RO(in12_label, powr1220_label, VCCA);
 247 static SENSOR_DEVICE_ATTR_RO(in13_label, powr1220_label, VCCINP);
 248
 249 static struct attribute *powr1220_attrs[] = {
 250         &sensor_dev_attr_in0_input.dev_attr.attr,
 251         &sensor_dev_attr_in1_input.dev_attr.attr,
 252         &sensor_dev_attr_in2_input.dev_attr.attr,
 253         &sensor_dev_attr_in3_input.dev_attr.attr,
 254         &sensor_dev_attr_in4_input.dev_attr.attr,
 255         &sensor_dev_attr_in5_input.dev_attr.attr,
 256         &sensor_dev_attr_in6_input.dev_attr.attr,
 257         &sensor_dev_attr_in7_input.dev_attr.attr,
 258         &sensor_dev_attr_in8_input.dev_attr.attr,
 259         &sensor_dev_attr_in9_input.dev_attr.attr,
 260         &sensor_dev_attr_in10_input.dev_attr.attr,
 261         &sensor_dev_attr_in11_input.dev_attr.attr,
 262         &sensor_dev_attr_in12_input.dev_attr.attr,
 263         &sensor_dev_attr_in13_input.dev_attr.attr,
 264
 265         &sensor_dev_attr_in0_highest.dev_attr.attr,
 266         &sensor_dev_attr_in1_highest.dev_attr.attr,
 267         &sensor_dev_attr_in2_highest.dev_attr.attr,
 268         &sensor_dev_attr_in3_highest.dev_attr.attr,
 269         &sensor_dev_attr_in4_highest.dev_attr.attr,
 270         &sensor_dev_attr_in5_highest.dev_attr.attr,
 271         &sensor_dev_attr_in6_highest.dev_attr.attr,
 272         &sensor_dev_attr_in7_highest.dev_attr.attr,
 273         &sensor_dev_attr_in8_highest.dev_attr.attr,
 274         &sensor_dev_attr_in9_highest.dev_attr.attr,
 275         &sensor_dev_attr_in10_highest.dev_attr.attr,
 276         &sensor_dev_attr_in11_highest.dev_attr.attr,
 277         &sensor_dev_attr_in12_highest.dev_attr.attr,
 278         &sensor_dev_attr_in13_highest.dev_attr.attr,
 279
 280         &sensor_dev_attr_in0_label.dev_attr.attr,
 281         &sensor_dev_attr_in1_label.dev_attr.attr,
 282         &sensor_dev_attr_in2_label.dev_attr.attr,
 283         &sensor_dev_attr_in3_label.dev_attr.attr,
 284         &sensor_dev_attr_in4_label.dev_attr.attr,
 285         &sensor_dev_attr_in5_label.dev_attr.attr,
 286         &sensor_dev_attr_in6_label.dev_attr.attr,
 287         &sensor_dev_attr_in7_label.dev_attr.attr,
 288         &sensor_dev_attr_in8_label.dev_attr.attr,
 289         &sensor_dev_attr_in9_label.dev_attr.attr,
 290         &sensor_dev_attr_in10_label.dev_attr.attr,
 291         &sensor_dev_attr_in11_label.dev_attr.attr,
 292         &sensor_dev_attr_in12_label.dev_attr.attr,
 293         &sensor_dev_attr_in13_label.dev_attr.attr,
 294
 295         NULL
 296 };
 297
 298 ATTRIBUTE_GROUPS(powr1220);
 299
 300 static int powr1220_probe(struct i2c_client *client)
 301 {
 302         struct powr1220_data *data;
 303         struct device *hwmon_dev;
 304
 305         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 306                 return -ENODEV;
 307
 308         data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 309         if (!data)
 310                 return -ENOMEM;
 311
 312         mutex_init(&data->update_lock);
 313         data->client = client;
 314
 315         hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
 316                         client->name, data, powr1220_groups);
 317
 318         return PTR_ERR_OR_ZERO(hwmon_dev);
 319 }
 320
 321 static const struct i2c_device_id powr1220_ids[] = {
 322         { "powr1220", 0, },
 323         { }
 324 };
 325
 326 MODULE_DEVICE_TABLE(i2c, powr1220_ids);
 327
 328 static struct i2c_driver powr1220_driver = {
 329         .class          = I2C_CLASS_HWMON,
 330         .driver = {
 331                 .name   = "powr1220",
 332         },
 333         .probe_new      = powr1220_probe,
 334         .id_table       = powr1220_ids,
 335 };
 336
 337 module_i2c_driver(powr1220_driver);
 338
 339 MODULE_AUTHOR("Scott Kanowitz");
 340 MODULE_DESCRIPTION("POWR1220 driver");
 341 MODULE_LICENSE("GPL");