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