1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
4 *
5 * Copyright (C) 2011 Ericsson AB.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/of_device.h>
11 #include <linux/init.h>
12 #include <linux/err.h>
13 #include <linux/slab.h>
14 #include <linux/i2c.h>
15 #include <linux/pmbus.h>
16 #include "pmbus.h"
17
18 #define UCD9200_PHASE_INFO 0xd2
19 #define UCD9200_DEVICE_ID 0xfd
20
21 enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
22 ucd9248 };
23
24 static const struct i2c_device_id ucd9200_id[] = {
25 {"ucd9200", ucd9200},
26 {"ucd9220", ucd9220},
27 {"ucd9222", ucd9222},
28 {"ucd9224", ucd9224},
29 {"ucd9240", ucd9240},
30 {"ucd9244", ucd9244},
31 {"ucd9246", ucd9246},
32 {"ucd9248", ucd9248},
33 {}
34 };
35 MODULE_DEVICE_TABLE(i2c, ucd9200_id);
36
37 static const struct of_device_id __maybe_unused ucd9200_of_match[] = {
38 {
39 .compatible = "ti,cd9200",
40 .data = (void *)ucd9200
41 },
42 {
43 .compatible = "ti,cd9220",
44 .data = (void *)ucd9220
45 },
46 {
47 .compatible = "ti,cd9222",
48 .data = (void *)ucd9222
49 },
50 {
51 .compatible = "ti,cd9224",
52 .data = (void *)ucd9224
53 },
54 {
55 .compatible = "ti,cd9240",
56 .data = (void *)ucd9240
57 },
58 {
59 .compatible = "ti,cd9244",
60 .data = (void *)ucd9244
61 },
62 {
63 .compatible = "ti,cd9246",
64 .data = (void *)ucd9246
65 },
66 {
67 .compatible = "ti,cd9248",
68 .data = (void *)ucd9248
69 },
70 { },
71 };
72 MODULE_DEVICE_TABLE(of, ucd9200_of_match);
73
ucd9200_probe(struct i2c_client * client)74 static int ucd9200_probe(struct i2c_client *client)
75 {
76 u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
77 struct pmbus_driver_info *info;
78 const struct i2c_device_id *mid;
79 enum chips chip;
80 int i, j, ret;
81
82 if (!i2c_check_functionality(client->adapter,
83 I2C_FUNC_SMBUS_BYTE_DATA |
84 I2C_FUNC_SMBUS_BLOCK_DATA))
85 return -ENODEV;
86
87 ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
88 block_buffer);
89 if (ret < 0) {
90 dev_err(&client->dev, "Failed to read device ID\n");
91 return ret;
92 }
93 block_buffer[ret] = '\0';
94 dev_info(&client->dev, "Device ID %s\n", block_buffer);
95
96 for (mid = ucd9200_id; mid->name[0]; mid++) {
97 if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
98 break;
99 }
100 if (!mid->name[0]) {
101 dev_err(&client->dev, "Unsupported device\n");
102 return -ENODEV;
103 }
104
105 if (client->dev.of_node)
106 chip = (enum chips)of_device_get_match_data(&client->dev);
107 else
108 chip = mid->driver_data;
109
110 if (chip != ucd9200 && strcmp(client->name, mid->name) != 0)
111 dev_notice(&client->dev,
112 "Device mismatch: Configured %s, detected %s\n",
113 client->name, mid->name);
114
115 info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
116 GFP_KERNEL);
117 if (!info)
118 return -ENOMEM;
119
120 ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
121 block_buffer);
122 if (ret < 0) {
123 dev_err(&client->dev, "Failed to read phase information\n");
124 return ret;
125 }
126
127 /*
128 * Calculate number of configured pages (rails) from PHASE_INFO
129 * register.
130 * Rails have to be sequential, so we can abort after finding
131 * the first unconfigured rail.
132 */
133 info->pages = 0;
134 for (i = 0; i < ret; i++) {
135 if (!block_buffer[i])
136 break;
137 info->pages++;
138 }
139 if (!info->pages) {
140 dev_err(&client->dev, "No rails configured\n");
141 return -ENODEV;
142 }
143 dev_info(&client->dev, "%d rails configured\n", info->pages);
144
145 /*
146 * Set PHASE registers on all pages to 0xff to ensure that phase
147 * specific commands will apply to all phases of a given page (rail).
148 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
149 * READ_IOUT will return the sum of currents of all phases of a rail,
150 * and READ_TEMPERATURE2 will return the maximum temperature detected
151 * for the phases of the rail.
152 */
153 for (i = 0; i < info->pages; i++) {
154 /*
155 * Setting PAGE & PHASE fails once in a while for no obvious
156 * reason, so we need to retry a couple of times.
157 */
158 for (j = 0; j < 3; j++) {
159 ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
160 if (ret < 0)
161 continue;
162 ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
163 0xff);
164 if (ret < 0)
165 continue;
166 break;
167 }
168 if (ret < 0) {
169 dev_err(&client->dev,
170 "Failed to initialize PHASE registers\n");
171 return ret;
172 }
173 }
174 if (info->pages > 1)
175 i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
176
177 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
178 PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
179 PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
180 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
181 PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
182 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
183
184 for (i = 1; i < info->pages; i++)
185 info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
186 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
187 PMBUS_HAVE_POUT |
188 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
189
190 /* ucd9240 supports a single fan */
191 if (mid->driver_data == ucd9240)
192 info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
193
194 return pmbus_do_probe(client, info);
195 }
196
197 /* This is the driver that will be inserted */
198 static struct i2c_driver ucd9200_driver = {
199 .driver = {
200 .name = "ucd9200",
201 .of_match_table = of_match_ptr(ucd9200_of_match),
202 },
203 .probe_new = ucd9200_probe,
204 .id_table = ucd9200_id,
205 };
206
207 module_i2c_driver(ucd9200_driver);
208
209 MODULE_AUTHOR("Guenter Roeck");
210 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
211 MODULE_LICENSE("GPL");
212 MODULE_IMPORT_NS(PMBUS);
213