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)
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