Merge remote-tracking branch 'stable/linux-5.15.y' into rpi-5.15.y
[platform/kernel/linux-rpi.git] / drivers / mfd / menf21bmc.c
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
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
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");