cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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menf21bmc.c (3046B)

      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");