1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Hardware monitoring driver for PMBus devices
4 *
5 * Copyright (c) 2010, 2011 Ericsson AB.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/err.h>
12 #include <linux/slab.h>
13 #include <linux/mutex.h>
14 #include <linux/i2c.h>
15 #include <linux/pmbus.h>
16 #include "pmbus.h"
17
18 struct pmbus_device_info {
19 int pages;
20 u32 flags;
21 };
22
23 static const struct i2c_device_id pmbus_id[];
24
25 /*
26 * Find sensor groups and status registers on each page.
27 */
pmbus_find_sensor_groups(struct i2c_client * client,struct pmbus_driver_info * info)28 static void pmbus_find_sensor_groups(struct i2c_client *client,
29 struct pmbus_driver_info *info)
30 {
31 int page;
32
33 /* Sensors detected on page 0 only */
34 if (pmbus_check_word_register(client, 0, PMBUS_READ_VIN))
35 info->func[0] |= PMBUS_HAVE_VIN;
36 if (pmbus_check_word_register(client, 0, PMBUS_READ_VCAP))
37 info->func[0] |= PMBUS_HAVE_VCAP;
38 if (pmbus_check_word_register(client, 0, PMBUS_READ_IIN))
39 info->func[0] |= PMBUS_HAVE_IIN;
40 if (pmbus_check_word_register(client, 0, PMBUS_READ_PIN))
41 info->func[0] |= PMBUS_HAVE_PIN;
42 if (info->func[0]
43 && pmbus_check_byte_register(client, 0, PMBUS_STATUS_INPUT))
44 info->func[0] |= PMBUS_HAVE_STATUS_INPUT;
45 if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_12) &&
46 pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_1)) {
47 info->func[0] |= PMBUS_HAVE_FAN12;
48 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_12))
49 info->func[0] |= PMBUS_HAVE_STATUS_FAN12;
50 }
51 if (pmbus_check_byte_register(client, 0, PMBUS_FAN_CONFIG_34) &&
52 pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_3)) {
53 info->func[0] |= PMBUS_HAVE_FAN34;
54 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
55 info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
56 }
57 if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1))
58 info->func[0] |= PMBUS_HAVE_TEMP;
59 if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_2))
60 info->func[0] |= PMBUS_HAVE_TEMP2;
61 if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
62 info->func[0] |= PMBUS_HAVE_TEMP3;
63 if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
64 | PMBUS_HAVE_TEMP3)
65 && pmbus_check_byte_register(client, 0,
66 PMBUS_STATUS_TEMPERATURE))
67 info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
68
69 /* Sensors detected on all pages */
70 for (page = 0; page < info->pages; page++) {
71 if (pmbus_check_word_register(client, page, PMBUS_READ_VOUT)) {
72 info->func[page] |= PMBUS_HAVE_VOUT;
73 if (pmbus_check_byte_register(client, page,
74 PMBUS_STATUS_VOUT))
75 info->func[page] |= PMBUS_HAVE_STATUS_VOUT;
76 }
77 if (pmbus_check_word_register(client, page, PMBUS_READ_IOUT)) {
78 info->func[page] |= PMBUS_HAVE_IOUT;
79 if (pmbus_check_byte_register(client, 0,
80 PMBUS_STATUS_IOUT))
81 info->func[page] |= PMBUS_HAVE_STATUS_IOUT;
82 }
83 if (pmbus_check_word_register(client, page, PMBUS_READ_POUT))
84 info->func[page] |= PMBUS_HAVE_POUT;
85 }
86 }
87
88 /*
89 * Identify chip parameters.
90 */
pmbus_identify(struct i2c_client * client,struct pmbus_driver_info * info)91 static int pmbus_identify(struct i2c_client *client,
92 struct pmbus_driver_info *info)
93 {
94 int ret = 0;
95
96 if (!info->pages) {
97 /*
98 * Check if the PAGE command is supported. If it is,
99 * keep setting the page number until it fails or until the
100 * maximum number of pages has been reached. Assume that
101 * this is the number of pages supported by the chip.
102 */
103 if (pmbus_check_byte_register(client, 0, PMBUS_PAGE)) {
104 int page;
105
106 for (page = 1; page < PMBUS_PAGES; page++) {
107 if (pmbus_set_page(client, page, 0xff) < 0)
108 break;
109 }
110 pmbus_set_page(client, 0, 0xff);
111 info->pages = page;
112 } else {
113 info->pages = 1;
114 }
115
116 pmbus_clear_faults(client);
117 }
118
119 if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
120 int vout_mode, i;
121
122 vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
123 if (vout_mode >= 0 && vout_mode != 0xff) {
124 switch (vout_mode >> 5) {
125 case 0:
126 break;
127 case 1:
128 info->format[PSC_VOLTAGE_OUT] = vid;
129 for (i = 0; i < info->pages; i++)
130 info->vrm_version[i] = vr11;
131 break;
132 case 2:
133 info->format[PSC_VOLTAGE_OUT] = direct;
134 break;
135 default:
136 ret = -ENODEV;
137 goto abort;
138 }
139 }
140 }
141
142 /*
143 * We should check if the COEFFICIENTS register is supported.
144 * If it is, and the chip is configured for direct mode, we can read
145 * the coefficients from the chip, one set per group of sensor
146 * registers.
147 *
148 * To do this, we will need access to a chip which actually supports the
149 * COEFFICIENTS command, since the command is too complex to implement
150 * without testing it. Until then, abort if a chip configured for direct
151 * mode was detected.
152 */
153 if (info->format[PSC_VOLTAGE_OUT] == direct) {
154 ret = -ENODEV;
155 goto abort;
156 }
157
158 /* Try to find sensor groups */
159 pmbus_find_sensor_groups(client, info);
160 abort:
161 return ret;
162 }
163
pmbus_probe(struct i2c_client * client)164 static int pmbus_probe(struct i2c_client *client)
165 {
166 struct pmbus_driver_info *info;
167 struct pmbus_platform_data *pdata = NULL;
168 struct device *dev = &client->dev;
169 struct pmbus_device_info *device_info;
170
171 info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL);
172 if (!info)
173 return -ENOMEM;
174
175 device_info = (struct pmbus_device_info *)i2c_match_id(pmbus_id, client)->driver_data;
176 if (device_info->flags & PMBUS_SKIP_STATUS_CHECK) {
177 pdata = devm_kzalloc(dev, sizeof(struct pmbus_platform_data),
178 GFP_KERNEL);
179 if (!pdata)
180 return -ENOMEM;
181
182 pdata->flags = PMBUS_SKIP_STATUS_CHECK;
183 }
184
185 info->pages = device_info->pages;
186 info->identify = pmbus_identify;
187 dev->platform_data = pdata;
188
189 return pmbus_do_probe(client, info);
190 }
191
192 static const struct pmbus_device_info pmbus_info_one = {
193 .pages = 1,
194 .flags = 0
195 };
196 static const struct pmbus_device_info pmbus_info_zero = {
197 .pages = 0,
198 .flags = 0
199 };
200 static const struct pmbus_device_info pmbus_info_one_skip = {
201 .pages = 1,
202 .flags = PMBUS_SKIP_STATUS_CHECK
203 };
204
205 /*
206 * Use driver_data to set the number of pages supported by the chip.
207 */
208 static const struct i2c_device_id pmbus_id[] = {
209 {"adp4000", (kernel_ulong_t)&pmbus_info_one},
210 {"bmr453", (kernel_ulong_t)&pmbus_info_one},
211 {"bmr454", (kernel_ulong_t)&pmbus_info_one},
212 {"dps460", (kernel_ulong_t)&pmbus_info_one_skip},
213 {"dps650ab", (kernel_ulong_t)&pmbus_info_one_skip},
214 {"dps800", (kernel_ulong_t)&pmbus_info_one_skip},
215 {"max20796", (kernel_ulong_t)&pmbus_info_one},
216 {"mdt040", (kernel_ulong_t)&pmbus_info_one},
217 {"ncp4200", (kernel_ulong_t)&pmbus_info_one},
218 {"ncp4208", (kernel_ulong_t)&pmbus_info_one},
219 {"pdt003", (kernel_ulong_t)&pmbus_info_one},
220 {"pdt006", (kernel_ulong_t)&pmbus_info_one},
221 {"pdt012", (kernel_ulong_t)&pmbus_info_one},
222 {"pmbus", (kernel_ulong_t)&pmbus_info_zero},
223 {"sgd009", (kernel_ulong_t)&pmbus_info_one_skip},
224 {"tps40400", (kernel_ulong_t)&pmbus_info_one},
225 {"tps544b20", (kernel_ulong_t)&pmbus_info_one},
226 {"tps544b25", (kernel_ulong_t)&pmbus_info_one},
227 {"tps544c20", (kernel_ulong_t)&pmbus_info_one},
228 {"tps544c25", (kernel_ulong_t)&pmbus_info_one},
229 {"udt020", (kernel_ulong_t)&pmbus_info_one},
230 {}
231 };
232
233 MODULE_DEVICE_TABLE(i2c, pmbus_id);
234
235 /* This is the driver that will be inserted */
236 static struct i2c_driver pmbus_driver = {
237 .driver = {
238 .name = "pmbus",
239 },
240 .probe_new = pmbus_probe,
241 .id_table = pmbus_id,
242 };
243
244 module_i2c_driver(pmbus_driver);
245
246 MODULE_AUTHOR("Guenter Roeck");
247 MODULE_DESCRIPTION("Generic PMBus driver");
248 MODULE_LICENSE("GPL");
249 MODULE_IMPORT_NS(PMBUS);
250