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
20 static struct mfd_cell menf21bmc_cell[] = {
21 { .name = "menf21bmc_wdt", },
22 { .name = "menf21bmc_led", },
23 { .name = "menf21bmc_hwmon", }
24 };
25
menf21bmc_wdt_exit_prod_mode(struct i2c_client * client)26 static 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
51 static int
menf21bmc_probe(struct i2c_client * client,const struct i2c_device_id * ids)52 menf21bmc_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
105 static const struct i2c_device_id menf21bmc_id_table[] = {
106 { "menf21bmc" },
107 { }
108 };
109 MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
110
111 static struct i2c_driver menf21bmc_driver = {
112 .driver.name = "menf21bmc",
113 .id_table = menf21bmc_id_table,
114 .probe = menf21bmc_probe,
115 };
116
117 module_i2c_driver(menf21bmc_driver);
118
119 MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
120 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
121 MODULE_LICENSE("GPL v2");
122