LXR linux/drivers/mfd/menf21bmc.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
   4 *
   5 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/device.h>
  10#include <linux/module.h>
  11#include <linux/i2c.h>
  12#include <linux/mfd/core.h>
  13
  14#define BMC_CMD_WDT_EXIT_PROD   0x18
  15#define BMC_CMD_WDT_PROD_STAT   0x19
  16#define BMC_CMD_REV_MAJOR       0x80
  17#define BMC_CMD_REV_MINOR       0x81
  18#define BMC_CMD_REV_MAIN        0x82
  19
  20static struct mfd_cell menf21bmc_cell[] = {
  21        { .name = "menf21bmc_wdt", },
  22        { .name = "menf21bmc_led", },
  23        { .name = "menf21bmc_hwmon", }
  24};
  25
  26static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
  27{
  28        int val, ret;
  29
  30        val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
  31        if (val < 0)
  32                return val;
  33
  34        /*
  35         * Production mode should be not active after delivery of the Board.
  36         * To be sure we check it, inform the user and exit the mode
  37         * if active.
  38         */
  39        if (val == 0x00) {
  40                dev_info(&client->dev,
  41                        "BMC in production mode. Exit production mode\n");
  42
  43                ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
  44                if (ret < 0)
  45                        return ret;
  46        }
  47
  48        return 0;
  49}
  50
  51static int
  52menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
  53{
  54        int rev_major, rev_minor, rev_main;
  55        int ret;
  56
  57        ret = i2c_check_functionality(client->adapter,
  58                                      I2C_FUNC_SMBUS_BYTE_DATA |
  59                                      I2C_FUNC_SMBUS_WORD_DATA |
  60                                      I2C_FUNC_SMBUS_BYTE);
  61        if (!ret)
  62                return -ENODEV;
  63
  64        rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
  65        if (rev_major < 0) {
  66                dev_err(&client->dev, "failed to get BMC major revision\n");
  67                return rev_major;
  68        }
  69
  70        rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
  71        if (rev_minor < 0) {
  72                dev_err(&client->dev, "failed to get BMC minor revision\n");
  73                return rev_minor;
  74        }
  75
  76        rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
  77        if (rev_main < 0) {
  78                dev_err(&client->dev, "failed to get BMC main revision\n");
  79                return rev_main;
  80        }
  81
  82        dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
  83                 rev_major, rev_minor, rev_main);
  84
  85        /*
  86         * We have to exit the Production Mode of the BMC to activate the
  87         * Watchdog functionality and the BIOS life sign monitoring.
  88         */
  89        ret = menf21bmc_wdt_exit_prod_mode(client);
  90        if (ret < 0) {
  91                dev_err(&client->dev, "failed to leave production mode\n");
  92                return ret;
  93        }
  94
  95        ret = devm_mfd_add_devices(&client->dev, 0, menf21bmc_cell,
  96                                   ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
  97        if (ret < 0) {
  98                dev_err(&client->dev, "failed to add BMC sub-devices\n");
  99                return ret;
 100        }
 101
 102        return 0;
 103}
 104
 105static const struct i2c_device_id menf21bmc_id_table[] = {
 106        { "menf21bmc" },
 107        { }
 108};
 109MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
 110
 111static struct i2c_driver menf21bmc_driver = {
 112        .driver.name    = "menf21bmc",
 113        .id_table       = menf21bmc_id_table,
 114        .probe          = menf21bmc_probe,
 115};
 116
 117module_i2c_driver(menf21bmc_driver);
 118
 119MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
 120MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 121MODULE_LICENSE("GPL v2");
 122