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
15 struct dps920ab_data {
16 char *mfr_model;
17 char *mfr_id;
18 };
19
dps920ab_read_word_data(struct i2c_client * client,int page,int phase,int reg)20 static 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
dps920ab_write_word_data(struct i2c_client * client,int page,int reg,u16 word)52 static 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
68 static 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
dps920ab_mfr_id_show(struct seq_file * s,void * data)90 static 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
99 DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_id);
100
dps920ab_mfr_model_show(struct seq_file * s,void * data)101 static 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
110 DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_model);
111
dps920ab_init_debugfs(struct dps920ab_data * data,struct i2c_client * client)112 static 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
dps920ab_probe(struct i2c_client * client)136 static 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
186 static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
187 { .compatible = "delta,dps920ab", },
188 {}
189 };
190
191 MODULE_DEVICE_TABLE(of, dps920ab_of_match);
192
193 static 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
201 module_i2c_driver(dps920ab_driver);
202
203 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
204 MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
205 MODULE_LICENSE("GPL");
206 MODULE_IMPORT_NS(PMBUS);
207
