Quelle  cgbc-hwmon.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * cgbc-hwmon - Congatec Board Controller hardware monitoring driver
 *
 * Copyright (C) 2024 Thomas Richard <thomas.richard@bootlin.com>
 */

#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/mfd/cgbc.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#define CGBC_HWMON_CMD_SENSOR  0x77
#define CGBC_HWMON_CMD_SENSOR_DATA_SIZE 0x05

#define CGBC_HWMON_TYPE_MASK GENMASK(6, 5)
#define CGBC_HWMON_ID_MASK GENMASK(4, 0)
#define CGBC_HWMON_ACTIVE_BIT BIT(7)

struct cgbc_hwmon_sensor {
 enum hwmon_sensor_types type;
 bool active;
 unsigned int index;
 unsigned int channel;
 const char *label;
};

struct cgbc_hwmon_data {
 struct cgbc_device_data *cgbc;
 unsigned int nb_sensors;
 struct cgbc_hwmon_sensor *sensors;
};

enum cgbc_sensor_types {
 CGBC_HWMON_TYPE_TEMP = 1,
 CGBC_HWMON_TYPE_IN,
 CGBC_HWMON_TYPE_FAN
};

static const char * const cgbc_hwmon_labels_temp[] = {
 "CPU Temperature",
 "Box Temperature",
 "Ambient Temperature",
 "Board Temperature",
 "Carrier Temperature",
 "Chipset Temperature",
 "Video Temperature",
 "Other Temperature",
 "TOPDIM Temperature",
 "BOTTOMDIM Temperature",
};

static const struct {
 enum hwmon_sensor_types type;
 const char *label;
} cgbc_hwmon_labels_in[] = {
 { hwmon_in, "CPU Voltage" },
 { hwmon_in, "DC Runtime Voltage" },
 { hwmon_in, "DC Standby Voltage" },
 { hwmon_in, "CMOS Battery Voltage" },
 { hwmon_in, "Battery Voltage" },
 { hwmon_in, "AC Voltage" },
 { hwmon_in, "Other Voltage" },
 { hwmon_in, "5V Voltage" },
 { hwmon_in, "5V Standby Voltage" },
 { hwmon_in, "3V3 Voltage" },
 { hwmon_in, "3V3 Standby Voltage" },
 { hwmon_in, "VCore A Voltage" },
 { hwmon_in, "VCore B Voltage" },
 { hwmon_in, "12V Voltage" },
 { hwmon_curr, "DC Current" },
 { hwmon_curr, "5V Current" },
 { hwmon_curr, "12V Current" },
};

#define CGBC_HWMON_NB_IN_SENSORS 14

static const char * const cgbc_hwmon_labels_fan[] = {
 "CPU Fan",
 "Box Fan",
 "Ambient Fan",
 "Chipset Fan",
 "Video Fan",
 "Other Fan",
};

static int cgbc_hwmon_cmd(struct cgbc_device_data *cgbc, u8 index, u8 *data)
{
 u8 cmd[2] = {CGBC_HWMON_CMD_SENSOR, index};

 return cgbc_command(cgbc, cmd, sizeof(cmd), data, CGBC_HWMON_CMD_SENSOR_DATA_SIZE, NULL);
}

static int cgbc_hwmon_probe_sensors(struct device *dev, struct cgbc_hwmon_data *hwmon)
{
 struct cgbc_device_data *cgbc = hwmon->cgbc;
 struct cgbc_hwmon_sensor *sensor = hwmon->sensors;
 u8 data[CGBC_HWMON_CMD_SENSOR_DATA_SIZE], nb_sensors, i;
 int ret;

 ret = cgbc_hwmon_cmd(cgbc, 0, &data[0]);
 if (ret)
  return ret;

 nb_sensors = data[0];

 hwmon->sensors = devm_kzalloc(dev, sizeof(*hwmon->sensors) * nb_sensors, GFP_KERNEL);
 if (!hwmon->sensors)
  return -ENOMEM;

 sensor = hwmon->sensors;

 for (i = 0; i < nb_sensors; i++) {
  enum cgbc_sensor_types type;
  unsigned int channel;

  /*
 * No need to request data for the first sensor.
 * We got data for the first sensor when we ask the number of sensors to the Board
 * Controller.
 */
  if (i) {
   ret = cgbc_hwmon_cmd(cgbc, i, &data[0]);
   if (ret)
    return ret;
  }

  type = FIELD_GET(CGBC_HWMON_TYPE_MASK, data[1]);
  channel = FIELD_GET(CGBC_HWMON_ID_MASK, data[1]) - 1;

  if (type == CGBC_HWMON_TYPE_TEMP && channel < ARRAY_SIZE(cgbc_hwmon_labels_temp)) {
   sensor->type = hwmon_temp;
   sensor->label = cgbc_hwmon_labels_temp[channel];
  } else if (type == CGBC_HWMON_TYPE_IN &&
      channel < ARRAY_SIZE(cgbc_hwmon_labels_in)) {
   /*
 * The Board Controller doesn't differentiate current and voltage sensors.
 * Get the sensor type from cgbc_hwmon_labels_in[channel].type instead.
 */
   sensor->type = cgbc_hwmon_labels_in[channel].type;
   sensor->label = cgbc_hwmon_labels_in[channel].label;
  } else if (type == CGBC_HWMON_TYPE_FAN &&
      channel < ARRAY_SIZE(cgbc_hwmon_labels_fan)) {
   sensor->type = hwmon_fan;
   sensor->label = cgbc_hwmon_labels_fan[channel];
  } else {
   dev_warn(dev, "Board Controller returned an unknown sensor (type=%d, channel=%d), ignore it",
     type, channel);
   continue;
  }

  sensor->active = FIELD_GET(CGBC_HWMON_ACTIVE_BIT, data[1]);
  sensor->channel = channel;
  sensor->index = i;
  sensor++;
  hwmon->nb_sensors++;
 }

 return 0;
}

static struct cgbc_hwmon_sensor *cgbc_hwmon_find_sensor(struct cgbc_hwmon_data *hwmon,
       enum hwmon_sensor_types type, int channel)
{
 struct cgbc_hwmon_sensor *sensor = NULL;
 int i;

 /*
 * The Board Controller doesn't differentiate current and voltage sensors.
 * The channel value (from the Board Controller point of view) shall be computed for current
 * sensors.
 */
 if (type == hwmon_curr)
  channel += CGBC_HWMON_NB_IN_SENSORS;

 for (i = 0; i < hwmon->nb_sensors; i++) {
  if (hwmon->sensors[i].type == type && hwmon->sensors[i].channel == channel) {
   sensor = &hwmon->sensors[i];
   break;
  }
 }

 return sensor;
}

static int cgbc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
      long *val)
{
 struct cgbc_hwmon_data *hwmon = dev_get_drvdata(dev);
 struct cgbc_hwmon_sensor *sensor = cgbc_hwmon_find_sensor(hwmon, type, channel);
 struct cgbc_device_data *cgbc = hwmon->cgbc;
 u8 data[CGBC_HWMON_CMD_SENSOR_DATA_SIZE];
 int ret;

 ret = cgbc_hwmon_cmd(cgbc, sensor->index, &data[0]);
 if (ret)
  return ret;

 *val = (data[3] << 8) | data[2];

 /*
 * For the Board Controller 1lsb = 0.1 degree centigrade.
 * Other units are as expected.
 */
 if (sensor->type == hwmon_temp)
  *val *= 100;

 return 0;
}

static umode_t cgbc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
         int channel)
{
 struct cgbc_hwmon_data *data = (struct cgbc_hwmon_data *)_data;
 struct cgbc_hwmon_sensor *sensor;

 sensor = cgbc_hwmon_find_sensor(data, type, channel);
 if (!sensor)
  return 0;

 return sensor->active ? 0444 : 0;
}

static int cgbc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
      int channel, const char **str)
{
 struct cgbc_hwmon_data *hwmon = dev_get_drvdata(dev);
 struct cgbc_hwmon_sensor *sensor = cgbc_hwmon_find_sensor(hwmon, type, channel);

 *str = sensor->label;

 return 0;
}

static const struct hwmon_channel_info * const cgbc_hwmon_info[] = {
 HWMON_CHANNEL_INFO(temp,
      HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
      HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
      HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
      HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
      HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL),
 HWMON_CHANNEL_INFO(in,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
      HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL),
 HWMON_CHANNEL_INFO(curr,
      HWMON_C_INPUT | HWMON_C_LABEL, HWMON_C_INPUT | HWMON_C_LABEL,
      HWMON_C_INPUT | HWMON_C_LABEL),
 HWMON_CHANNEL_INFO(fan,
      HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL,
      HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL,
      HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL),
 NULL
};

static const struct hwmon_ops cgbc_hwmon_ops = {
 .is_visible = cgbc_hwmon_is_visible,
 .read = cgbc_hwmon_read,
 .read_string = cgbc_hwmon_read_string,
};

static const struct hwmon_chip_info cgbc_chip_info = {
 .ops = &cgbc_hwmon_ops,
 .info = cgbc_hwmon_info,
};

static int cgbc_hwmon_probe(struct platform_device *pdev)
{
 struct cgbc_device_data *cgbc = dev_get_drvdata(pdev->dev.parent);
 struct device *dev = &pdev->dev;
 struct cgbc_hwmon_data *data;
 struct device *hwmon_dev;
 int ret;

 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 if (!data)
  return -ENOMEM;

 data->cgbc = cgbc;

 ret = cgbc_hwmon_probe_sensors(dev, data);
 if (ret)
  return dev_err_probe(dev, ret, "Failed to probe sensors");

 hwmon_dev = devm_hwmon_device_register_with_info(dev, "cgbc_hwmon", data, &cgbc_chip_info,
        NULL);
 return PTR_ERR_OR_ZERO(hwmon_dev);
}

static struct platform_driver cgbc_hwmon_driver = {
 .driver = {
  .name = "cgbc-hwmon",
 },
 .probe = cgbc_hwmon_probe,
};

module_platform_driver(cgbc_hwmon_driver);

MODULE_AUTHOR("Thomas Richard ");
MODULE_DESCRIPTION("Congatec Board Controller Hardware Monitoring Driver");
MODULE_LICENSE("GPL");