xref: /openbmc/linux/drivers/hwmon/pmbus/pmbus.c (revision aac28965)
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  */
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  */
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 
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) {
177 		pdata = devm_kzalloc(dev, sizeof(struct pmbus_platform_data),
178 				     GFP_KERNEL);
179 		if (!pdata)
180 			return -ENOMEM;
181 
182 		pdata->flags = device_info->flags;
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 
197 static const struct pmbus_device_info pmbus_info_zero = {
198 	.pages = 0,
199 	.flags = 0
200 };
201 
202 static const struct pmbus_device_info pmbus_info_one_skip = {
203 	.pages = 1,
204 	.flags = PMBUS_SKIP_STATUS_CHECK
205 };
206 
207 static const struct pmbus_device_info pmbus_info_one_status = {
208 	.pages = 1,
209 	.flags = PMBUS_READ_STATUS_AFTER_FAILED_CHECK
210 };
211 
212 /*
213  * Use driver_data to set the number of pages supported by the chip.
214  */
215 static const struct i2c_device_id pmbus_id[] = {
216 	{"adp4000", (kernel_ulong_t)&pmbus_info_one},
217 	{"bmr310", (kernel_ulong_t)&pmbus_info_one_status},
218 	{"bmr453", (kernel_ulong_t)&pmbus_info_one},
219 	{"bmr454", (kernel_ulong_t)&pmbus_info_one},
220 	{"bmr456", (kernel_ulong_t)&pmbus_info_one},
221 	{"bmr457", (kernel_ulong_t)&pmbus_info_one},
222 	{"bmr458", (kernel_ulong_t)&pmbus_info_one_status},
223 	{"bmr480", (kernel_ulong_t)&pmbus_info_one_status},
224 	{"bmr490", (kernel_ulong_t)&pmbus_info_one_status},
225 	{"bmr491", (kernel_ulong_t)&pmbus_info_one_status},
226 	{"bmr492", (kernel_ulong_t)&pmbus_info_one},
227 	{"dps460", (kernel_ulong_t)&pmbus_info_one_skip},
228 	{"dps650ab", (kernel_ulong_t)&pmbus_info_one_skip},
229 	{"dps800", (kernel_ulong_t)&pmbus_info_one_skip},
230 	{"max20796", (kernel_ulong_t)&pmbus_info_one},
231 	{"mdt040", (kernel_ulong_t)&pmbus_info_one},
232 	{"ncp4200", (kernel_ulong_t)&pmbus_info_one},
233 	{"ncp4208", (kernel_ulong_t)&pmbus_info_one},
234 	{"pdt003", (kernel_ulong_t)&pmbus_info_one},
235 	{"pdt006", (kernel_ulong_t)&pmbus_info_one},
236 	{"pdt012", (kernel_ulong_t)&pmbus_info_one},
237 	{"pmbus", (kernel_ulong_t)&pmbus_info_zero},
238 	{"sgd009", (kernel_ulong_t)&pmbus_info_one_skip},
239 	{"tps40400", (kernel_ulong_t)&pmbus_info_one},
240 	{"tps544b20", (kernel_ulong_t)&pmbus_info_one},
241 	{"tps544b25", (kernel_ulong_t)&pmbus_info_one},
242 	{"tps544c20", (kernel_ulong_t)&pmbus_info_one},
243 	{"tps544c25", (kernel_ulong_t)&pmbus_info_one},
244 	{"udt020", (kernel_ulong_t)&pmbus_info_one},
245 	{}
246 };
247 
248 MODULE_DEVICE_TABLE(i2c, pmbus_id);
249 
250 /* This is the driver that will be inserted */
251 static struct i2c_driver pmbus_driver = {
252 	.driver = {
253 		   .name = "pmbus",
254 		   },
255 	.probe_new = pmbus_probe,
256 	.id_table = pmbus_id,
257 };
258 
259 module_i2c_driver(pmbus_driver);
260 
261 MODULE_AUTHOR("Guenter Roeck");
262 MODULE_DESCRIPTION("Generic PMBus driver");
263 MODULE_LICENSE("GPL");
264 MODULE_IMPORT_NS(PMBUS);
265