LXR linux/drivers/mfd/menf21bmc.c

   1/*
   2 *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
   3 *
   4 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
   5 *
   6 *  This program is free software; you can redistribute  it and/or modify it
   7 *  under  the terms of  the GNU General  Public License as published by the
   8 *  Free Software Foundation;  either version 2 of the  License, or (at your
   9 *  option) any later version.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/device.h>
  14#include <linux/module.h>
  15#include <linux/i2c.h>
  16#include <linux/mfd/core.h>
  17
  18#define BMC_CMD_WDT_EXIT_PROD   0x18
  19#define BMC_CMD_WDT_PROD_STAT   0x19
  20#define BMC_CMD_REV_MAJOR       0x80
  21#define BMC_CMD_REV_MINOR       0x81
  22#define BMC_CMD_REV_MAIN        0x82
  23
  24static struct mfd_cell menf21bmc_cell[] = {
  25        { .name = "menf21bmc_wdt", },
  26        { .name = "menf21bmc_led", },
  27        { .name = "menf21bmc_hwmon", }
  28};
  29
  30static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
  31{
  32        int val, ret;
  33
  34        val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
  35        if (val < 0)
  36                return val;
  37
  38        /*
  39         * Production mode should be not active after delivery of the Board.
  40         * To be sure we check it, inform the user and exit the mode
  41         * if active.
  42         */
  43        if (val == 0x00) {
  44                dev_info(&client->dev,
  45                        "BMC in production mode. Exit production mode\n");
  46
  47                ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
  48                if (ret < 0)
  49                        return ret;
  50        }
  51
  52        return 0;
  53}
  54
  55static int
  56menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
  57{
  58        int rev_major, rev_minor, rev_main;
  59        int ret;
  60
  61        ret = i2c_check_functionality(client->adapter,
  62                                      I2C_FUNC_SMBUS_BYTE_DATA |
  63                                      I2C_FUNC_SMBUS_WORD_DATA |
  64                                      I2C_FUNC_SMBUS_BYTE);
  65        if (!ret)
  66                return -ENODEV;
  67
  68        rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
  69        if (rev_major < 0) {
  70                dev_err(&client->dev, "failed to get BMC major revision\n");
  71                return rev_major;
  72        }
  73
  74        rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
  75        if (rev_minor < 0) {
  76                dev_err(&client->dev, "failed to get BMC minor revision\n");
  77                return rev_minor;
  78        }
  79
  80        rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
  81        if (rev_main < 0) {
  82                dev_err(&client->dev, "failed to get BMC main revision\n");
  83                return rev_main;
  84        }
  85
  86        dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
  87                 rev_major, rev_minor, rev_main);
  88
  89        /*
  90         * We have to exit the Production Mode of the BMC to activate the
  91         * Watchdog functionality and the BIOS life sign monitoring.
  92         */
  93        ret = menf21bmc_wdt_exit_prod_mode(client);
  94        if (ret < 0) {
  95                dev_err(&client->dev, "failed to leave production mode\n");
  96                return ret;
  97        }
  98
  99        ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
 100                              ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
 101        if (ret < 0) {
 102                dev_err(&client->dev, "failed to add BMC sub-devices\n");
 103                return ret;
 104        }
 105
 106        return 0;
 107}
 108
 109static int menf21bmc_remove(struct i2c_client *client)
 110{
 111        mfd_remove_devices(&client->dev);
 112        return 0;
 113}
 114
 115static const struct i2c_device_id menf21bmc_id_table[] = {
 116        { "menf21bmc" },
 117        { }
 118};
 119MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
 120
 121static struct i2c_driver menf21bmc_driver = {
 122        .driver.name    = "menf21bmc",
 123        .id_table       = menf21bmc_id_table,
 124        .probe          = menf21bmc_probe,
 125        .remove         = menf21bmc_remove,
 126};
 127
 128module_i2c_driver(menf21bmc_driver);
 129
 130MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
 131MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 132MODULE_LICENSE("GPL v2");
 133