1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for Delta DPS920AB PSU
4 *
5 * Copyright (C) 2021 Delta Networks, Inc.
6 * Copyright (C) 2021 Sartura Ltd.
7 */
8
9#include <linux/debugfs.h>
10#include <linux/i2c.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include "pmbus.h"
14
15struct dps920ab_data {
16	char *mfr_model;
17	char *mfr_id;
18};
19
20static int dps920ab_read_word_data(struct i2c_client *client, int page, int phase, int reg)
21{
22	/*
23	 * This masks commands which are not supported.
24	 * PSU advertises that all features are supported,
25	 * in reality that unfortunately is not true.
26	 * So enable only those that the datasheet confirms.
27	 */
28	switch (reg) {
29	case PMBUS_FAN_COMMAND_1:
30	case PMBUS_IOUT_OC_WARN_LIMIT:
31	case PMBUS_STATUS_WORD:
32	case PMBUS_READ_VIN:
33	case PMBUS_READ_IIN:
34	case PMBUS_READ_VOUT:
35	case PMBUS_READ_IOUT:
36	case PMBUS_READ_TEMPERATURE_1:
37	case PMBUS_READ_TEMPERATURE_2:
38	case PMBUS_READ_TEMPERATURE_3:
39	case PMBUS_READ_FAN_SPEED_1:
40	case PMBUS_READ_POUT:
41	case PMBUS_READ_PIN:
42	case PMBUS_MFR_VOUT_MIN:
43	case PMBUS_MFR_VOUT_MAX:
44	case PMBUS_MFR_IOUT_MAX:
45	case PMBUS_MFR_POUT_MAX:
46		return pmbus_read_word_data(client, page, phase, reg);
47	default:
48		return -ENXIO;
49	}
50}
51
52static int dps920ab_write_word_data(struct i2c_client *client, int page, int reg,
53				    u16 word)
54{
55	/*
56	 * This masks commands which are not supported.
57	 * PSU only has one R/W register and that is
58	 * for the fan.
59	 */
60	switch (reg) {
61	case PMBUS_FAN_COMMAND_1:
62		return pmbus_write_word_data(client, page, reg, word);
63	default:
64		return -EACCES;
65	}
66}
67
68static struct pmbus_driver_info dps920ab_info = {
69	.pages = 1,
70
71	.format[PSC_VOLTAGE_IN] = linear,
72	.format[PSC_VOLTAGE_OUT] = linear,
73	.format[PSC_CURRENT_IN] = linear,
74	.format[PSC_CURRENT_OUT] = linear,
75	.format[PSC_POWER] = linear,
76	.format[PSC_FAN] = linear,
77	.format[PSC_TEMPERATURE] = linear,
78
79	.func[0] =
80		PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
81		PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
82		PMBUS_HAVE_TEMP  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
83		PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 |
84		PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
85		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
86	.read_word_data = dps920ab_read_word_data,
87	.write_word_data = dps920ab_write_word_data,
88};
89
90static int dps920ab_mfr_id_show(struct seq_file *s, void *data)
91{
92	struct dps920ab_data *priv = s->private;
93
94	seq_printf(s, "%s\n", priv->mfr_id);
95
96	return 0;
97}
98
99DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_id);
100
101static int dps920ab_mfr_model_show(struct seq_file *s, void *data)
102{
103	struct dps920ab_data *priv = s->private;
104
105	seq_printf(s, "%s\n", priv->mfr_model);
106
107	return 0;
108}
109
110DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_model);
111
112static void dps920ab_init_debugfs(struct dps920ab_data *data, struct i2c_client *client)
113{
114	struct dentry *debugfs_dir;
115	struct dentry *root;
116
117	root = pmbus_get_debugfs_dir(client);
118	if (!root)
119		return;
120
121	debugfs_dir = debugfs_create_dir(client->name, root);
122
123	debugfs_create_file("mfr_id",
124			    0400,
125			    debugfs_dir,
126			    data,
127			    &dps920ab_mfr_id_fops);
128
129	debugfs_create_file("mfr_model",
130			    0400,
131			    debugfs_dir,
132			    data,
133			    &dps920ab_mfr_model_fops);
134}
135
136static int dps920ab_probe(struct i2c_client *client)
137{
138	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
139	struct dps920ab_data *data;
140	int ret;
141
142	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
143	if (!data)
144		return -ENOMEM;
145
146	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
147	if (ret < 0) {
148		dev_err(&client->dev, "Failed to read Manufacturer ID\n");
149		return ret;
150	}
151
152	buf[ret] = '\0';
153	if (ret != 5 || strncmp(buf, "DELTA", 5)) {
154		buf[ret] = '\0';
155		dev_err(&client->dev, "Unsupported Manufacturer ID '%s'\n", buf);
156		return -ENODEV;
157	}
158	data->mfr_id = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
159	if (!data->mfr_id)
160		return -ENOMEM;
161
162	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
163	if (ret < 0) {
164		dev_err(&client->dev, "Failed to read Manufacturer Model\n");
165		return ret;
166	}
167
168	buf[ret] = '\0';
169	if (ret != 11 || strncmp(buf, "DPS-920AB", 9)) {
170		dev_err(&client->dev, "Unsupported Manufacturer Model '%s'\n", buf);
171		return -ENODEV;
172	}
173	data->mfr_model = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
174	if (!data->mfr_model)
175		return -ENOMEM;
176
177	ret = pmbus_do_probe(client, &dps920ab_info);
178	if (ret)
179		return ret;
180
181	dps920ab_init_debugfs(data, client);
182
183	return 0;
184}
185
186static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
187	{ .compatible = "delta,dps920ab", },
188	{}
189};
190
191MODULE_DEVICE_TABLE(of, dps920ab_of_match);
192
193static struct i2c_driver dps920ab_driver = {
194	.driver = {
195		   .name = "dps920ab",
196		   .of_match_table = of_match_ptr(dps920ab_of_match),
197	},
198	.probe = dps920ab_probe,
199};
200
201module_i2c_driver(dps920ab_driver);
202
203MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
204MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
205MODULE_LICENSE("GPL");
206MODULE_IMPORT_NS(PMBUS);
207