xref: /linux/drivers/hwmon/pmbus/ucd9200.c (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
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 
74 static int ucd9200_probe(struct i2c_client *client,
75 			 const struct i2c_device_id *id)
76 {
77 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
78 	struct pmbus_driver_info *info;
79 	const struct i2c_device_id *mid;
80 	enum chips chip;
81 	int i, j, ret;
82 
83 	if (!i2c_check_functionality(client->adapter,
84 				     I2C_FUNC_SMBUS_BYTE_DATA |
85 				     I2C_FUNC_SMBUS_BLOCK_DATA))
86 		return -ENODEV;
87 
88 	ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
89 					block_buffer);
90 	if (ret < 0) {
91 		dev_err(&client->dev, "Failed to read device ID\n");
92 		return ret;
93 	}
94 	block_buffer[ret] = '\0';
95 	dev_info(&client->dev, "Device ID %s\n", block_buffer);
96 
97 	for (mid = ucd9200_id; mid->name[0]; mid++) {
98 		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
99 			break;
100 	}
101 	if (!mid->name[0]) {
102 		dev_err(&client->dev, "Unsupported device\n");
103 		return -ENODEV;
104 	}
105 
106 	if (client->dev.of_node)
107 		chip = (enum chips)of_device_get_match_data(&client->dev);
108 	else
109 		chip = id->driver_data;
110 
111 	if (chip != ucd9200 && chip != mid->driver_data)
112 		dev_notice(&client->dev,
113 			   "Device mismatch: Configured %s, detected %s\n",
114 			   id->name, mid->name);
115 
116 	info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
117 			    GFP_KERNEL);
118 	if (!info)
119 		return -ENOMEM;
120 
121 	ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
122 					block_buffer);
123 	if (ret < 0) {
124 		dev_err(&client->dev, "Failed to read phase information\n");
125 		return ret;
126 	}
127 
128 	/*
129 	 * Calculate number of configured pages (rails) from PHASE_INFO
130 	 * register.
131 	 * Rails have to be sequential, so we can abort after finding
132 	 * the first unconfigured rail.
133 	 */
134 	info->pages = 0;
135 	for (i = 0; i < ret; i++) {
136 		if (!block_buffer[i])
137 			break;
138 		info->pages++;
139 	}
140 	if (!info->pages) {
141 		dev_err(&client->dev, "No rails configured\n");
142 		return -ENODEV;
143 	}
144 	dev_info(&client->dev, "%d rails configured\n", info->pages);
145 
146 	/*
147 	 * Set PHASE registers on all pages to 0xff to ensure that phase
148 	 * specific commands will apply to all phases of a given page (rail).
149 	 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
150 	 * READ_IOUT will return the sum of currents of all phases of a rail,
151 	 * and READ_TEMPERATURE2 will return the maximum temperature detected
152 	 * for the the phases of the rail.
153 	 */
154 	for (i = 0; i < info->pages; i++) {
155 		/*
156 		 * Setting PAGE & PHASE fails once in a while for no obvious
157 		 * reason, so we need to retry a couple of times.
158 		 */
159 		for (j = 0; j < 3; j++) {
160 			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
161 			if (ret < 0)
162 				continue;
163 			ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
164 							0xff);
165 			if (ret < 0)
166 				continue;
167 			break;
168 		}
169 		if (ret < 0) {
170 			dev_err(&client->dev,
171 				"Failed to initialize PHASE registers\n");
172 			return ret;
173 		}
174 	}
175 	if (info->pages > 1)
176 		i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
177 
178 	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
179 			PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
180 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
181 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
182 			PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
183 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
184 
185 	for (i = 1; i < info->pages; i++)
186 		info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
187 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
188 			PMBUS_HAVE_POUT |
189 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
190 
191 	/* ucd9240 supports a single fan */
192 	if (mid->driver_data == ucd9240)
193 		info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
194 
195 	return pmbus_do_probe(client, mid, info);
196 }
197 
198 /* This is the driver that will be inserted */
199 static struct i2c_driver ucd9200_driver = {
200 	.driver = {
201 		.name = "ucd9200",
202 		.of_match_table = of_match_ptr(ucd9200_of_match),
203 	},
204 	.probe = ucd9200_probe,
205 	.remove = pmbus_do_remove,
206 	.id_table = ucd9200_id,
207 };
208 
209 module_i2c_driver(ucd9200_driver);
210 
211 MODULE_AUTHOR("Guenter Roeck");
212 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
213 MODULE_LICENSE("GPL");
214