drivers/hwmon/menf21bmc_hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
   4  *
   5  *  This is the core hwmon driver of the MEN 14F021P00 BMC.
   6  *  The BMC monitors the board voltages which can be access with this
   7  *  driver through sysfs.
   8  *
   9  *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/hwmon.h>
  16 #include <linux/hwmon-sysfs.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/slab.h>
  19 #include <linux/i2c.h>
  20 #include <linux/err.h>
  21
  22 #define DRV_NAME  "menf21bmc_hwmon"
  23
  24 #define BMC_VOLT_COUNT  5
  25 #define MENF21BMC_V33   0
  26 #define MENF21BMC_V5    1
  27 #define MENF21BMC_V12   2
  28 #define MENF21BMC_V5_SB 3
  29 #define MENF21BMC_VBAT  4
  30
  31 #define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
  32 #define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
  33 #define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
  34
  35 struct menf21bmc_hwmon {
  36         bool valid;
  37         struct i2c_client *i2c_client;
  38         unsigned long last_update;
  39         int in_val[BMC_VOLT_COUNT];
  40         int in_min[BMC_VOLT_COUNT];
  41         int in_max[BMC_VOLT_COUNT];
  42 };
  43
  44 static const char *const input_names[] = {
  45         [MENF21BMC_V33]         = "MON_3_3V",
  46         [MENF21BMC_V5]          = "MON_5V",
  47         [MENF21BMC_V12]         = "MON_12V",
  48         [MENF21BMC_V5_SB]       = "5V_STANDBY",
  49         [MENF21BMC_VBAT]        = "VBAT"
  50 };
  51
  52 static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
  53 {
  54         int i;
  55         int val;
  56         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
  57         struct menf21bmc_hwmon *data_ret = drv_data;
  58
  59         if (time_after(jiffies, drv_data->last_update + HZ)
  60             || !drv_data->valid) {
  61                 for (i = 0; i < BMC_VOLT_COUNT; i++) {
  62                         val = i2c_smbus_read_word_data(drv_data->i2c_client,
  63                                                        IDX_TO_VOLT_INP_CMD(i));
  64                         if (val < 0) {
  65                                 data_ret = ERR_PTR(val);
  66                                 goto abort;
  67                         }
  68                         drv_data->in_val[i] = val;
  69                 }
  70                 drv_data->last_update = jiffies;
  71                 drv_data->valid = true;
  72         }
  73 abort:
  74         return data_ret;
  75 }
  76
  77 static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
  78 {
  79         int i, val;
  80
  81         for (i = 0; i < BMC_VOLT_COUNT; i++) {
  82                 val = i2c_smbus_read_word_data(drv_data->i2c_client,
  83                                                IDX_TO_VOLT_MIN_CMD(i));
  84                 if (val < 0)
  85                         return val;
  86
  87                 drv_data->in_min[i] = val;
  88
  89                 val = i2c_smbus_read_word_data(drv_data->i2c_client,
  90                                                IDX_TO_VOLT_MAX_CMD(i));
  91                 if (val < 0)
  92                         return val;
  93
  94                 drv_data->in_max[i] = val;
  95         }
  96         return 0;
  97 }
  98
  99 static ssize_t
 100 label_show(struct device *dev, struct device_attribute *devattr, char *buf)
 101 {
 102         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 103
 104         return sprintf(buf, "%s\n", input_names[attr->index]);
 105 }
 106
 107 static ssize_t
 108 in_show(struct device *dev, struct device_attribute *devattr, char *buf)
 109 {
 110         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 111         struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
 112
 113         if (IS_ERR(drv_data))
 114                 return PTR_ERR(drv_data);
 115
 116         return sprintf(buf, "%d\n", drv_data->in_val[attr->index]);
 117 }
 118
 119 static ssize_t
 120 min_show(struct device *dev, struct device_attribute *devattr, char *buf)
 121 {
 122         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 123         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
 124
 125         return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
 126 }
 127
 128 static ssize_t
 129 max_show(struct device *dev, struct device_attribute *devattr, char *buf)
 130 {
 131         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 132         struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
 133
 134         return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
 135 }
 136
 137 static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
 138 static SENSOR_DEVICE_ATTR_RO(in0_min, min, 0);
 139 static SENSOR_DEVICE_ATTR_RO(in0_max, max, 0);
 140 static SENSOR_DEVICE_ATTR_RO(in0_label, label, 0);
 141 static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
 142 static SENSOR_DEVICE_ATTR_RO(in1_min, min, 1);
 143 static SENSOR_DEVICE_ATTR_RO(in1_max, max, 1);
 144 static SENSOR_DEVICE_ATTR_RO(in1_label, label, 1);
 145 static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
 146 static SENSOR_DEVICE_ATTR_RO(in2_min, min, 2);
 147 static SENSOR_DEVICE_ATTR_RO(in2_max, max, 2);
 148 static SENSOR_DEVICE_ATTR_RO(in2_label, label, 2);
 149 static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
 150 static SENSOR_DEVICE_ATTR_RO(in3_min, min, 3);
 151 static SENSOR_DEVICE_ATTR_RO(in3_max, max, 3);
 152 static SENSOR_DEVICE_ATTR_RO(in3_label, label, 3);
 153 static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
 154 static SENSOR_DEVICE_ATTR_RO(in4_min, min, 4);
 155 static SENSOR_DEVICE_ATTR_RO(in4_max, max, 4);
 156 static SENSOR_DEVICE_ATTR_RO(in4_label, label, 4);
 157
 158 static struct attribute *menf21bmc_hwmon_attrs[] = {
 159         &sensor_dev_attr_in0_input.dev_attr.attr,
 160         &sensor_dev_attr_in0_min.dev_attr.attr,
 161         &sensor_dev_attr_in0_max.dev_attr.attr,
 162         &sensor_dev_attr_in0_label.dev_attr.attr,
 163
 164         &sensor_dev_attr_in1_input.dev_attr.attr,
 165         &sensor_dev_attr_in1_min.dev_attr.attr,
 166         &sensor_dev_attr_in1_max.dev_attr.attr,
 167         &sensor_dev_attr_in1_label.dev_attr.attr,
 168
 169         &sensor_dev_attr_in2_input.dev_attr.attr,
 170         &sensor_dev_attr_in2_min.dev_attr.attr,
 171         &sensor_dev_attr_in2_max.dev_attr.attr,
 172         &sensor_dev_attr_in2_label.dev_attr.attr,
 173
 174         &sensor_dev_attr_in3_input.dev_attr.attr,
 175         &sensor_dev_attr_in3_min.dev_attr.attr,
 176         &sensor_dev_attr_in3_max.dev_attr.attr,
 177         &sensor_dev_attr_in3_label.dev_attr.attr,
 178
 179         &sensor_dev_attr_in4_input.dev_attr.attr,
 180         &sensor_dev_attr_in4_min.dev_attr.attr,
 181         &sensor_dev_attr_in4_max.dev_attr.attr,
 182         &sensor_dev_attr_in4_label.dev_attr.attr,
 183         NULL
 184 };
 185
 186 ATTRIBUTE_GROUPS(menf21bmc_hwmon);
 187
 188 static int menf21bmc_hwmon_probe(struct platform_device *pdev)
 189 {
 190         int ret;
 191         struct menf21bmc_hwmon *drv_data;
 192         struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
 193         struct device *hwmon_dev;
 194
 195         drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
 196                                 GFP_KERNEL);
 197         if (!drv_data)
 198                 return -ENOMEM;
 199
 200         drv_data->i2c_client = i2c_client;
 201
 202         ret = menf21bmc_hwmon_get_volt_limits(drv_data);
 203         if (ret) {
 204                 dev_err(&pdev->dev, "failed to read sensor limits");
 205                 return ret;
 206         }
 207
 208         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
 209                                                    "menf21bmc", drv_data,
 210                                                    menf21bmc_hwmon_groups);
 211         if (IS_ERR(hwmon_dev))
 212                 return PTR_ERR(hwmon_dev);
 213
 214         dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
 215
 216         return 0;
 217 }
 218
 219 static struct platform_driver menf21bmc_hwmon = {
 220         .probe          = menf21bmc_hwmon_probe,
 221         .driver         = {
 222                 .name           = DRV_NAME,
 223         },
 224 };
 225
 226 module_platform_driver(menf21bmc_hwmon);
 227
 228 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 229 MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
 230 MODULE_LICENSE("GPL v2");
 231 MODULE_ALIAS("platform:menf21bmc_hwmon");