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
24 static struct mfd_cell menf21bmc_cell[] = {
25 { .name = "menf21bmc_wdt", },
26 { .name = "menf21bmc_led", },
27 { .name = "menf21bmc_hwmon", }
28 };
29
menf21bmc_wdt_exit_prod_mode(struct i2c_client * client)30 static 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
55 static int
menf21bmc_probe(struct i2c_client * client,const struct i2c_device_id * ids)56 menf21bmc_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
menf21bmc_remove(struct i2c_client * client)109 static int menf21bmc_remove(struct i2c_client *client)
110 {
111 mfd_remove_devices(&client->dev);
112 return 0;
113 }
114
115 static const struct i2c_device_id menf21bmc_id_table[] = {
116 { "menf21bmc" },
117 { }
118 };
119 MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
120
121 static 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
128 module_i2c_driver(menf21bmc_driver);
129
130 MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
131 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
132 MODULE_LICENSE("GPL v2");
133