drivers/hwmon/lm95241.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
0004  *
0005  * The LM95241 is a sensor chip made by National Semiconductors.
0006  * It reports up to three temperatures (its own plus up to two external ones).
0007  * Complete datasheet can be obtained from National's website at:
0008  *   http://www.national.com/ds.cgi/LM/LM95241.pdf
0009  */
0010
0011 #include <linux/bitops.h>
0012 #include <linux/err.h>
0013 #include <linux/i2c.h>
0014 #include <linux/init.h>
0015 #include <linux/jiffies.h>
0016 #include <linux/hwmon.h>
0017 #include <linux/module.h>
0018 #include <linux/mutex.h>
0019 #include <linux/slab.h>
0020
0021 #define DEVNAME "lm95241"
0022
0023 static const unsigned short normal_i2c[] = {
0024     0x19, 0x2a, 0x2b, I2C_CLIENT_END };
0025
0026 /* LM95241 registers */
0027 #define LM95241_REG_R_MAN_ID        0xFE
0028 #define LM95241_REG_R_CHIP_ID       0xFF
0029 #define LM95241_REG_R_STATUS        0x02
0030 #define LM95241_REG_RW_CONFIG       0x03
0031 #define LM95241_REG_RW_REM_FILTER   0x06
0032 #define LM95241_REG_RW_TRUTHERM     0x07
0033 #define LM95241_REG_W_ONE_SHOT      0x0F
0034 #define LM95241_REG_R_LOCAL_TEMPH   0x10
0035 #define LM95241_REG_R_REMOTE1_TEMPH 0x11
0036 #define LM95241_REG_R_REMOTE2_TEMPH 0x12
0037 #define LM95241_REG_R_LOCAL_TEMPL   0x20
0038 #define LM95241_REG_R_REMOTE1_TEMPL 0x21
0039 #define LM95241_REG_R_REMOTE2_TEMPL 0x22
0040 #define LM95241_REG_RW_REMOTE_MODEL 0x30
0041
0042 /* LM95241 specific bitfields */
0043 #define CFG_STOP    BIT(6)
0044 #define CFG_CR0076  0x00
0045 #define CFG_CR0182  BIT(4)
0046 #define CFG_CR1000  BIT(5)
0047 #define CFG_CR2700  (BIT(4) | BIT(5))
0048 #define CFG_CRMASK  (BIT(4) | BIT(5))
0049 #define R1MS_MASK   BIT(0)
0050 #define R2MS_MASK   BIT(2)
0051 #define R1DF_MASK   BIT(1)
0052 #define R2DF_MASK   BIT(2)
0053 #define R1FE_MASK   BIT(0)
0054 #define R2FE_MASK   BIT(2)
0055 #define R1DM        BIT(0)
0056 #define R2DM        BIT(1)
0057 #define TT1_SHIFT   0
0058 #define TT2_SHIFT   4
0059 #define TT_OFF      0
0060 #define TT_ON       1
0061 #define TT_MASK     7
0062 #define NATSEMI_MAN_ID  0x01
0063 #define LM95231_CHIP_ID 0xA1
0064 #define LM95241_CHIP_ID 0xA4
0065
0066 static const u8 lm95241_reg_address[] = {
0067     LM95241_REG_R_LOCAL_TEMPH,
0068     LM95241_REG_R_LOCAL_TEMPL,
0069     LM95241_REG_R_REMOTE1_TEMPH,
0070     LM95241_REG_R_REMOTE1_TEMPL,
0071     LM95241_REG_R_REMOTE2_TEMPH,
0072     LM95241_REG_R_REMOTE2_TEMPL
0073 };
0074
0075 /* Client data (each client gets its own) */
0076 struct lm95241_data {
0077     struct i2c_client *client;
0078     struct mutex update_lock;
0079     unsigned long last_updated; /* in jiffies */
0080     unsigned long interval;     /* in milli-seconds */
0081     bool valid;     /* false until following fields are valid */
0082     /* registers values */
0083     u8 temp[ARRAY_SIZE(lm95241_reg_address)];
0084     u8 status, config, model, trutherm;
0085 };
0086
0087 /* Conversions */
0088 static int temp_from_reg_signed(u8 val_h, u8 val_l)
0089 {
0090     s16 val_hl = (val_h << 8) | val_l;
0091     return val_hl * 1000 / 256;
0092 }
0093
0094 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
0095 {
0096     u16 val_hl = (val_h << 8) | val_l;
0097     return val_hl * 1000 / 256;
0098 }
0099
0100 static struct lm95241_data *lm95241_update_device(struct device *dev)
0101 {
0102     struct lm95241_data *data = dev_get_drvdata(dev);
0103     struct i2c_client *client = data->client;
0104
0105     mutex_lock(&data->update_lock);
0106
0107     if (time_after(jiffies, data->last_updated
0108                + msecs_to_jiffies(data->interval)) ||
0109         !data->valid) {
0110         int i;
0111
0112         dev_dbg(dev, "Updating lm95241 data.\n");
0113         for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
0114             data->temp[i]
0115               = i2c_smbus_read_byte_data(client,
0116                              lm95241_reg_address[i]);
0117
0118         data->status = i2c_smbus_read_byte_data(client,
0119                             LM95241_REG_R_STATUS);
0120         data->last_updated = jiffies;
0121         data->valid = true;
0122     }
0123
0124     mutex_unlock(&data->update_lock);
0125
0126     return data;
0127 }
0128
0129 static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
0130                  long *val)
0131 {
0132     struct lm95241_data *data = dev_get_drvdata(dev);
0133
0134     switch (attr) {
0135     case hwmon_chip_update_interval:
0136         *val = data->interval;
0137         return 0;
0138     default:
0139         return -EOPNOTSUPP;
0140     }
0141 }
0142
0143 static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
0144                  long *val)
0145 {
0146     struct lm95241_data *data = lm95241_update_device(dev);
0147
0148     switch (attr) {
0149     case hwmon_temp_input:
0150         if (!channel || (data->config & BIT(channel - 1)))
0151             *val = temp_from_reg_signed(data->temp[channel * 2],
0152                         data->temp[channel * 2 + 1]);
0153         else
0154             *val = temp_from_reg_unsigned(data->temp[channel * 2],
0155                         data->temp[channel * 2 + 1]);
0156         return 0;
0157     case hwmon_temp_min:
0158         if (channel == 1)
0159             *val = (data->config & R1DF_MASK) ? -128000 : 0;
0160         else
0161             *val = (data->config & R2DF_MASK) ? -128000 : 0;
0162         return 0;
0163     case hwmon_temp_max:
0164         if (channel == 1)
0165             *val = (data->config & R1DF_MASK) ? 127875 : 255875;
0166         else
0167             *val = (data->config & R2DF_MASK) ? 127875 : 255875;
0168         return 0;
0169     case hwmon_temp_type:
0170         if (channel == 1)
0171             *val = (data->model & R1MS_MASK) ? 1 : 2;
0172         else
0173             *val = (data->model & R2MS_MASK) ? 1 : 2;
0174         return 0;
0175     case hwmon_temp_fault:
0176         if (channel == 1)
0177             *val = !!(data->status & R1DM);
0178         else
0179             *val = !!(data->status & R2DM);
0180         return 0;
0181     default:
0182         return -EOPNOTSUPP;
0183     }
0184 }
0185
0186 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
0187             u32 attr, int channel, long *val)
0188 {
0189     switch (type) {
0190     case hwmon_chip:
0191         return lm95241_read_chip(dev, attr, channel, val);
0192     case hwmon_temp:
0193         return lm95241_read_temp(dev, attr, channel, val);
0194     default:
0195         return -EOPNOTSUPP;
0196     }
0197 }
0198
0199 static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
0200                   long val)
0201 {
0202     struct lm95241_data *data = dev_get_drvdata(dev);
0203     int convrate;
0204     u8 config;
0205     int ret;
0206
0207     mutex_lock(&data->update_lock);
0208
0209     switch (attr) {
0210     case hwmon_chip_update_interval:
0211         config = data->config & ~CFG_CRMASK;
0212         if (val < 130) {
0213             convrate = 76;
0214             config |= CFG_CR0076;
0215         } else if (val < 590) {
0216             convrate = 182;
0217             config |= CFG_CR0182;
0218         } else if (val < 1850) {
0219             convrate = 1000;
0220             config |= CFG_CR1000;
0221         } else {
0222             convrate = 2700;
0223             config |= CFG_CR2700;
0224         }
0225         data->interval = convrate;
0226         data->config = config;
0227         ret = i2c_smbus_write_byte_data(data->client,
0228                         LM95241_REG_RW_CONFIG, config);
0229         break;
0230     default:
0231         ret = -EOPNOTSUPP;
0232         break;
0233     }
0234     mutex_unlock(&data->update_lock);
0235     return ret;
0236 }
0237
0238 static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
0239                   long val)
0240 {
0241     struct lm95241_data *data = dev_get_drvdata(dev);
0242     struct i2c_client *client = data->client;
0243     int ret;
0244
0245     mutex_lock(&data->update_lock);
0246
0247     switch (attr) {
0248     case hwmon_temp_min:
0249         if (channel == 1) {
0250             if (val < 0)
0251                 data->config |= R1DF_MASK;
0252             else
0253                 data->config &= ~R1DF_MASK;
0254         } else {
0255             if (val < 0)
0256                 data->config |= R2DF_MASK;
0257             else
0258                 data->config &= ~R2DF_MASK;
0259         }
0260         data->valid = false;
0261         ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
0262                         data->config);
0263         break;
0264     case hwmon_temp_max:
0265         if (channel == 1) {
0266             if (val <= 127875)
0267                 data->config |= R1DF_MASK;
0268             else
0269                 data->config &= ~R1DF_MASK;
0270         } else {
0271             if (val <= 127875)
0272                 data->config |= R2DF_MASK;
0273             else
0274                 data->config &= ~R2DF_MASK;
0275         }
0276         data->valid = false;
0277         ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
0278                         data->config);
0279         break;
0280     case hwmon_temp_type:
0281         if (val != 1 && val != 2) {
0282             ret = -EINVAL;
0283             break;
0284         }
0285         if (channel == 1) {
0286             data->trutherm &= ~(TT_MASK << TT1_SHIFT);
0287             if (val == 1) {
0288                 data->model |= R1MS_MASK;
0289                 data->trutherm |= (TT_ON << TT1_SHIFT);
0290             } else {
0291                 data->model &= ~R1MS_MASK;
0292                 data->trutherm |= (TT_OFF << TT1_SHIFT);
0293             }
0294         } else {
0295             data->trutherm &= ~(TT_MASK << TT2_SHIFT);
0296             if (val == 1) {
0297                 data->model |= R2MS_MASK;
0298                 data->trutherm |= (TT_ON << TT2_SHIFT);
0299             } else {
0300                 data->model &= ~R2MS_MASK;
0301                 data->trutherm |= (TT_OFF << TT2_SHIFT);
0302             }
0303         }
0304         ret = i2c_smbus_write_byte_data(client,
0305                         LM95241_REG_RW_REMOTE_MODEL,
0306                         data->model);
0307         if (ret < 0)
0308             break;
0309         ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
0310                         data->trutherm);
0311         break;
0312     default:
0313         ret = -EOPNOTSUPP;
0314         break;
0315     }
0316
0317     mutex_unlock(&data->update_lock);
0318
0319     return ret;
0320 }
0321
0322 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
0323              u32 attr, int channel, long val)
0324 {
0325     switch (type) {
0326     case hwmon_chip:
0327         return lm95241_write_chip(dev, attr, channel, val);
0328     case hwmon_temp:
0329         return lm95241_write_temp(dev, attr, channel, val);
0330     default:
0331         return -EOPNOTSUPP;
0332     }
0333 }
0334
0335 static umode_t lm95241_is_visible(const void *data,
0336                   enum hwmon_sensor_types type,
0337                   u32 attr, int channel)
0338 {
0339     switch (type) {
0340     case hwmon_chip:
0341         switch (attr) {
0342         case hwmon_chip_update_interval:
0343             return 0644;
0344         }
0345         break;
0346     case hwmon_temp:
0347         switch (attr) {
0348         case hwmon_temp_input:
0349             return 0444;
0350         case hwmon_temp_fault:
0351             return 0444;
0352         case hwmon_temp_min:
0353         case hwmon_temp_max:
0354         case hwmon_temp_type:
0355             return 0644;
0356         }
0357         break;
0358     default:
0359         break;
0360     }
0361     return 0;
0362 }
0363
0364 /* Return 0 if detection is successful, -ENODEV otherwise */
0365 static int lm95241_detect(struct i2c_client *new_client,
0366               struct i2c_board_info *info)
0367 {
0368     struct i2c_adapter *adapter = new_client->adapter;
0369     const char *name;
0370     int mfg_id, chip_id;
0371
0372     if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
0373         return -ENODEV;
0374
0375     mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
0376     if (mfg_id != NATSEMI_MAN_ID)
0377         return -ENODEV;
0378
0379     chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
0380     switch (chip_id) {
0381     case LM95231_CHIP_ID:
0382         name = "lm95231";
0383         break;
0384     case LM95241_CHIP_ID:
0385         name = "lm95241";
0386         break;
0387     default:
0388         return -ENODEV;
0389     }
0390
0391     /* Fill the i2c board info */
0392     strlcpy(info->type, name, I2C_NAME_SIZE);
0393     return 0;
0394 }
0395
0396 static void lm95241_init_client(struct i2c_client *client,
0397                 struct lm95241_data *data)
0398 {
0399     data->interval = 1000;
0400     data->config = CFG_CR1000;
0401     data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
0402
0403     i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
0404     i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
0405                   R1FE_MASK | R2FE_MASK);
0406     i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
0407                   data->trutherm);
0408     i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
0409                   data->model);
0410 }
0411
0412 static const struct hwmon_channel_info *lm95241_info[] = {
0413     HWMON_CHANNEL_INFO(chip,
0414                HWMON_C_UPDATE_INTERVAL),
0415     HWMON_CHANNEL_INFO(temp,
0416                HWMON_T_INPUT,
0417                HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
0418                HWMON_T_TYPE | HWMON_T_FAULT,
0419                HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
0420                HWMON_T_TYPE | HWMON_T_FAULT),
0421     NULL
0422 };
0423
0424 static const struct hwmon_ops lm95241_hwmon_ops = {
0425     .is_visible = lm95241_is_visible,
0426     .read = lm95241_read,
0427     .write = lm95241_write,
0428 };
0429
0430 static const struct hwmon_chip_info lm95241_chip_info = {
0431     .ops = &lm95241_hwmon_ops,
0432     .info = lm95241_info,
0433 };
0434
0435 static int lm95241_probe(struct i2c_client *client)
0436 {
0437     struct device *dev = &client->dev;
0438     struct lm95241_data *data;
0439     struct device *hwmon_dev;
0440
0441     data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
0442     if (!data)
0443         return -ENOMEM;
0444
0445     data->client = client;
0446     mutex_init(&data->update_lock);
0447
0448     /* Initialize the LM95241 chip */
0449     lm95241_init_client(client, data);
0450
0451     hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
0452                                data,
0453                                &lm95241_chip_info,
0454                                NULL);
0455     return PTR_ERR_OR_ZERO(hwmon_dev);
0456 }
0457
0458 /* Driver data (common to all clients) */
0459 static const struct i2c_device_id lm95241_id[] = {
0460     { "lm95231", 0 },
0461     { "lm95241", 0 },
0462     { }
0463 };
0464 MODULE_DEVICE_TABLE(i2c, lm95241_id);
0465
0466 static struct i2c_driver lm95241_driver = {
0467     .class      = I2C_CLASS_HWMON,
0468     .driver = {
0469         .name   = DEVNAME,
0470     },
0471     .probe_new  = lm95241_probe,
0472     .id_table   = lm95241_id,
0473     .detect     = lm95241_detect,
0474     .address_list   = normal_i2c,
0475 };
0476
0477 module_i2c_driver(lm95241_driver);
0478
0479 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
0480 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
0481 MODULE_LICENSE("GPL");