linux/drivers/hwmon/menf21bmc_hwmon.c
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   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
  35struct 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
  44static 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
  52static 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        }
  73abort:
  74        return data_ret;
  75}
  76
  77static 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
  99static ssize_t
 100label_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
 107static ssize_t
 108in_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
 119static ssize_t
 120min_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
 128static ssize_t
 129max_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
 137static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
 138static SENSOR_DEVICE_ATTR_RO(in0_min, min, 0);
 139static SENSOR_DEVICE_ATTR_RO(in0_max, max, 0);
 140static SENSOR_DEVICE_ATTR_RO(in0_label, label, 0);
 141static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
 142static SENSOR_DEVICE_ATTR_RO(in1_min, min, 1);
 143static SENSOR_DEVICE_ATTR_RO(in1_max, max, 1);
 144static SENSOR_DEVICE_ATTR_RO(in1_label, label, 1);
 145static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
 146static SENSOR_DEVICE_ATTR_RO(in2_min, min, 2);
 147static SENSOR_DEVICE_ATTR_RO(in2_max, max, 2);
 148static SENSOR_DEVICE_ATTR_RO(in2_label, label, 2);
 149static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
 150static SENSOR_DEVICE_ATTR_RO(in3_min, min, 3);
 151static SENSOR_DEVICE_ATTR_RO(in3_max, max, 3);
 152static SENSOR_DEVICE_ATTR_RO(in3_label, label, 3);
 153static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
 154static SENSOR_DEVICE_ATTR_RO(in4_min, min, 4);
 155static SENSOR_DEVICE_ATTR_RO(in4_max, max, 4);
 156static SENSOR_DEVICE_ATTR_RO(in4_label, label, 4);
 157
 158static 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
 186ATTRIBUTE_GROUPS(menf21bmc_hwmon);
 187
 188static 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
 219static struct platform_driver menf21bmc_hwmon = {
 220        .probe          = menf21bmc_hwmon_probe,
 221        .driver         = {
 222                .name           = DRV_NAME,
 223        },
 224};
 225
 226module_platform_driver(menf21bmc_hwmon);
 227
 228MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 229MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
 230MODULE_LICENSE("GPL v2");
 231MODULE_ALIAS("platform:menf21bmc_hwmon");
 232