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_device.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_new = 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