drivers/hwmon/menf21bmc_hwmon.c

   1 /*
   2  *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
   3  *
   4  *  This is the core hwmon driver of the MEN 14F021P00 BMC.
   5  *  The BMC monitors the board voltages which can be access with this
   6  *  driver through sysfs.
   7  *
   8  *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
   9  *
  10  *  This program is free software; you can redistribute  it and/or modify it
  11  *  under  the terms of  the GNU General  Public License as published by the
  12  *  Free Software Foundation;  either version 2 of the  License, or (at your
  13  *  option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/hwmon.h>
  20 #include <linux/hwmon-sysfs.h>
  21 #include <linux/jiffies.h>
  22 #include <linux/slab.h>
  23 #include <linux/i2c.h>
  24
  25 #define DRV_NAME  "menf21bmc_hwmon"
  26
  27 #define BMC_VOLT_COUNT  5
  28 #define MENF21BMC_V33   0
  29 #define MENF21BMC_V5    1
  30 #define MENF21BMC_V12   2
  31 #define MENF21BMC_V5_SB 3
  32 #define MENF21BMC_VBAT  4
  33
  34 #define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
  35 #define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
  36 #define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
  37
  38 struct menf21bmc_hwmon {
  39         bool valid;
  40         struct i2c_client *i2c_client;
  41         unsigned long last_update;
  42         int in_val[BMC_VOLT_COUNT];
  43         int in_min[BMC_VOLT_COUNT];
  44         int in_max[BMC_VOLT_COUNT];
  45 };
  46
  47 static const char *const input_names[] = {
  48         [MENF21BMC_V33]         = "MON_3_3V",
  49         [MENF21BMC_V5]          = "MON_5V",
  50         [MENF21BMC_V12]         = "MON_12V",
  51         [MENF21BMC_V5_SB]       = "5V_STANDBY",
  52         [MENF21BMC_VBAT]        = "VBAT"
  53 };
  54
  55 static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
  56 {
  57         int i;
  58         int val;
  59         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
  60         struct menf21bmc_hwmon *data_ret = drv_data;
  61
  62         if (time_after(jiffies, drv_data->last_update + HZ)
  63             || !drv_data->valid) {
  64                 for (i = 0; i < BMC_VOLT_COUNT; i++) {
  65                         val = i2c_smbus_read_word_data(drv_data->i2c_client,
  66                                                        IDX_TO_VOLT_INP_CMD(i));
  67                         if (val < 0) {
  68                                 data_ret = ERR_PTR(val);
  69                                 goto abort;
  70                         }
  71                         drv_data->in_val[i] = val;
  72                 }
  73                 drv_data->last_update = jiffies;
  74                 drv_data->valid = true;
  75         }
  76 abort:
  77         return data_ret;
  78 }
  79
  80 static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
  81 {
  82         int i, val;
  83
  84         for (i = 0; i < BMC_VOLT_COUNT; i++) {
  85                 val = i2c_smbus_read_word_data(drv_data->i2c_client,
  86                                                IDX_TO_VOLT_MIN_CMD(i));
  87                 if (val < 0)
  88                         return val;
  89
  90                 drv_data->in_min[i] = val;
  91
  92                 val = i2c_smbus_read_word_data(drv_data->i2c_client,
  93                                                IDX_TO_VOLT_MAX_CMD(i));
  94                 if (val < 0)
  95                         return val;
  96
  97                 drv_data->in_max[i] = val;
  98         }
  99         return 0;
 100 }
 101
 102 static ssize_t
 103 show_label(struct device *dev, struct device_attribute *devattr, char *buf)
 104 {
 105         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 106
 107         return sprintf(buf, "%s\n", input_names[attr->index]);
 108 }
 109
 110 static ssize_t
 111 show_in(struct device *dev, struct device_attribute *devattr, char *buf)
 112 {
 113         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 114         struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
 115
 116         if (IS_ERR(drv_data))
 117                 return PTR_ERR(drv_data);
 118
 119         return sprintf(buf, "%d\n", drv_data->in_val[attr->index]);
 120 }
 121
 122 static ssize_t
 123 show_min(struct device *dev, struct device_attribute *devattr, char *buf)
 124 {
 125         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 126         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
 127
 128         return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
 129 }
 130
 131 static ssize_t
 132 show_max(struct device *dev, struct device_attribute *devattr, char *buf)
 133 {
 134         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 135         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
 136
 137         return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
 138 }
 139
 140 #define create_voltage_sysfs(idx)                       \
 141 static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,     \
 142                         show_in, NULL, idx);            \
 143 static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,       \
 144                         show_min, NULL, idx);           \
 145 static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,       \
 146                         show_max, NULL, idx);           \
 147 static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,     \
 148                         show_label, NULL, idx);
 149
 150 create_voltage_sysfs(0);
 151 create_voltage_sysfs(1);
 152 create_voltage_sysfs(2);
 153 create_voltage_sysfs(3);
 154 create_voltage_sysfs(4);
 155
 156 static struct attribute *menf21bmc_hwmon_attrs[] = {
 157         &sensor_dev_attr_in0_input.dev_attr.attr,
 158         &sensor_dev_attr_in0_min.dev_attr.attr,
 159         &sensor_dev_attr_in0_max.dev_attr.attr,
 160         &sensor_dev_attr_in0_label.dev_attr.attr,
 161
 162         &sensor_dev_attr_in1_input.dev_attr.attr,
 163         &sensor_dev_attr_in1_min.dev_attr.attr,
 164         &sensor_dev_attr_in1_max.dev_attr.attr,
 165         &sensor_dev_attr_in1_label.dev_attr.attr,
 166
 167         &sensor_dev_attr_in2_input.dev_attr.attr,
 168         &sensor_dev_attr_in2_min.dev_attr.attr,
 169         &sensor_dev_attr_in2_max.dev_attr.attr,
 170         &sensor_dev_attr_in2_label.dev_attr.attr,
 171
 172         &sensor_dev_attr_in3_input.dev_attr.attr,
 173         &sensor_dev_attr_in3_min.dev_attr.attr,
 174         &sensor_dev_attr_in3_max.dev_attr.attr,
 175         &sensor_dev_attr_in3_label.dev_attr.attr,
 176
 177         &sensor_dev_attr_in4_input.dev_attr.attr,
 178         &sensor_dev_attr_in4_min.dev_attr.attr,
 179         &sensor_dev_attr_in4_max.dev_attr.attr,
 180         &sensor_dev_attr_in4_label.dev_attr.attr,
 181         NULL
 182 };
 183
 184 ATTRIBUTE_GROUPS(menf21bmc_hwmon);
 185
 186 static int menf21bmc_hwmon_probe(struct platform_device *pdev)
 187 {
 188         int ret;
 189         struct menf21bmc_hwmon *drv_data;
 190         struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
 191         struct device *hwmon_dev;
 192
 193         drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
 194                                 GFP_KERNEL);
 195         if (!drv_data)
 196                 return -ENOMEM;
 197
 198         drv_data->i2c_client = i2c_client;
 199
 200         ret = menf21bmc_hwmon_get_volt_limits(drv_data);
 201         if (ret) {
 202                 dev_err(&pdev->dev, "failed to read sensor limits");
 203                 return ret;
 204         }
 205
 206         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
 207                                                    "menf21bmc", drv_data,
 208                                                    menf21bmc_hwmon_groups);
 209         if (IS_ERR(hwmon_dev))
 210                 return PTR_ERR(hwmon_dev);
 211
 212         dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
 213
 214         return 0;
 215 }
 216
 217 static struct platform_driver menf21bmc_hwmon = {
 218         .probe          = menf21bmc_hwmon_probe,
 219         .driver         = {
 220                 .name           = DRV_NAME,
 221                 .owner          = THIS_MODULE,
 222         },
 223 };
 224
 225 module_platform_driver(menf21bmc_hwmon);
 226
 227 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 228 MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
 229 MODULE_LICENSE("GPL v2");
 230 MODULE_ALIAS("platform:menf21bmc_hwmon");