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.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
21enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
22	     ucd9248 };
23
24static 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};
35MODULE_DEVICE_TABLE(i2c, ucd9200_id);
36
37static 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};
72MODULE_DEVICE_TABLE(of, ucd9200_of_match);
73
74static 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 = (uintptr_t)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 */
198static struct i2c_driver ucd9200_driver = {
199	.driver = {
200		.name = "ucd9200",
201		.of_match_table = of_match_ptr(ucd9200_of_match),
202	},
203	.probe = ucd9200_probe,
204	.id_table = ucd9200_id,
205};
206
207module_i2c_driver(ucd9200_driver);
208
209MODULE_AUTHOR("Guenter Roeck");
210MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
211MODULE_LICENSE("GPL");
212MODULE_IMPORT_NS(PMBUS);
213