dps920ab.c

  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 const struct i2c_device_id dps920ab_device_id[] = {
194	{ "dps920ab" },
195	{}
196};
197MODULE_DEVICE_TABLE(i2c, dps920ab_device_id);
198
199static struct i2c_driver dps920ab_driver = {
200	.driver = {
201		   .name = "dps920ab",
202		   .of_match_table = of_match_ptr(dps920ab_of_match),
203	},
204	.probe = dps920ab_probe,
205	.id_table = dps920ab_device_id,
206};
207
208module_i2c_driver(dps920ab_driver);
209
210MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
211MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
212MODULE_LICENSE("GPL");
213MODULE_IMPORT_NS("PMBUS");