lt7182s.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Hardware monitoring driver for Analog Devices LT7182S
  4 *
  5 * Copyright (c) 2022 Guenter Roeck
  6 *
  7 */
  8
  9#include <linux/bits.h>
 10#include <linux/err.h>
 11#include <linux/i2c.h>
 12#include <linux/init.h>
 13#include <linux/kernel.h>
 14#include <linux/module.h>
 15#include <linux/of.h>
 16#include "pmbus.h"
 17
 18#define LT7182S_NUM_PAGES	2
 19
 20#define MFR_READ_EXTVCC		0xcd
 21#define MFR_READ_ITH		0xce
 22#define MFR_CONFIG_ALL_LT7182S	0xd1
 23#define MFR_IOUT_PEAK		0xd7
 24#define MFR_ADC_CONTROL_LT7182S 0xd8
 25
 26#define MFR_DEBUG_TELEMETRY	BIT(0)
 27
 28#define MFR_VOUT_PEAK		0xdd
 29#define MFR_VIN_PEAK		0xde
 30#define MFR_TEMPERATURE_1_PEAK	0xdf
 31#define MFR_CLEAR_PEAKS		0xe3
 32
 33#define MFR_CONFIG_IEEE		BIT(8)
 34
 35static int lt7182s_read_word_data(struct i2c_client *client, int page, int phase, int reg)
 36{
 37	int ret;
 38
 39	switch (reg) {
 40	case PMBUS_VIRT_READ_VMON:
 41		if (page == 0 || page == 1)
 42			ret = pmbus_read_word_data(client, page, phase, MFR_READ_ITH);
 43		else
 44			ret = pmbus_read_word_data(client, 0, phase, MFR_READ_EXTVCC);
 45		break;
 46	case PMBUS_VIRT_READ_IOUT_MAX:
 47		ret = pmbus_read_word_data(client, page, phase, MFR_IOUT_PEAK);
 48		break;
 49	case PMBUS_VIRT_READ_VOUT_MAX:
 50		ret = pmbus_read_word_data(client, page, phase, MFR_VOUT_PEAK);
 51		break;
 52	case PMBUS_VIRT_READ_VIN_MAX:
 53		ret = pmbus_read_word_data(client, page, phase, MFR_VIN_PEAK);
 54		break;
 55	case PMBUS_VIRT_READ_TEMP_MAX:
 56		ret = pmbus_read_word_data(client, page, phase, MFR_TEMPERATURE_1_PEAK);
 57		break;
 58	case PMBUS_VIRT_RESET_VIN_HISTORY:
 59		ret = (page == 0) ? 0 : -ENODATA;
 60		break;
 61	default:
 62		ret = -ENODATA;
 63		break;
 64	}
 65	return ret;
 66}
 67
 68static int lt7182s_write_word_data(struct i2c_client *client, int page, int reg, u16 word)
 69{
 70	int ret;
 71
 72	switch (reg) {
 73	case PMBUS_VIRT_RESET_VIN_HISTORY:
 74		ret = pmbus_write_byte(client, 0, MFR_CLEAR_PEAKS);
 75		break;
 76	default:
 77		ret = -ENODATA;
 78		break;
 79	}
 80	return ret;
 81}
 82
 83static struct pmbus_driver_info lt7182s_info = {
 84	.pages = LT7182S_NUM_PAGES,
 85	.format[PSC_VOLTAGE_IN] = linear,
 86	.format[PSC_VOLTAGE_OUT] = linear,
 87	.format[PSC_CURRENT_IN] = linear,
 88	.format[PSC_CURRENT_OUT] = linear,
 89	.format[PSC_TEMPERATURE] = linear,
 90	.format[PSC_POWER] = linear,
 91	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
 92	  PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
 93	  PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
 94	  PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
 95	.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
 96	  PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
 97	  PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
 98	  PMBUS_HAVE_STATUS_INPUT,
 99	.read_word_data = lt7182s_read_word_data,
100	.write_word_data = lt7182s_write_word_data,
101};
102
103static int lt7182s_probe(struct i2c_client *client)
104{
105	struct device *dev = &client->dev;
106	struct pmbus_driver_info *info;
107	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
108	int ret;
109
110	if (!i2c_check_functionality(client->adapter,
111				     I2C_FUNC_SMBUS_READ_BYTE_DATA |
112				     I2C_FUNC_SMBUS_READ_WORD_DATA |
113				     I2C_FUNC_SMBUS_READ_BLOCK_DATA))
114		return -ENODEV;
115
116	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
117	if (ret < 0) {
118		dev_err(dev, "Failed to read PMBUS_MFR_ID\n");
119		return ret;
120	}
121	if (ret != 3 || strncmp(buf, "ADI", 3)) {
122		buf[ret] = '\0';
123		dev_err(dev, "Manufacturer '%s' not supported\n", buf);
124		return -ENODEV;
125	}
126
127	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
128	if (ret < 0) {
129		dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
130		return ret;
131	}
132	if (ret != 7 || strncmp(buf, "LT7182S", 7)) {
133		buf[ret] = '\0';
134		dev_err(dev, "Model '%s' not supported\n", buf);
135		return -ENODEV;
136	}
137
138	info = devm_kmemdup(dev, &lt7182s_info,
139			    sizeof(struct pmbus_driver_info), GFP_KERNEL);
140	if (!info)
141		return -ENOMEM;
142
143	/* Set data format to IEEE754 if configured */
144	ret = i2c_smbus_read_word_data(client, MFR_CONFIG_ALL_LT7182S);
145	if (ret < 0)
146		return ret;
147	if (ret & MFR_CONFIG_IEEE) {
148		info->format[PSC_VOLTAGE_IN] = ieee754;
149		info->format[PSC_VOLTAGE_OUT] = ieee754;
150		info->format[PSC_CURRENT_IN] = ieee754;
151		info->format[PSC_CURRENT_OUT] = ieee754;
152		info->format[PSC_TEMPERATURE] = ieee754;
153		info->format[PSC_POWER] = ieee754;
154	}
155
156	/* Enable VMON output if configured */
157	ret = i2c_smbus_read_byte_data(client, MFR_ADC_CONTROL_LT7182S);
158	if (ret < 0)
159		return ret;
160	if (ret & MFR_DEBUG_TELEMETRY) {
161		info->pages = 3;
162		info->func[0] |= PMBUS_HAVE_VMON;
163		info->func[1] |= PMBUS_HAVE_VMON;
164		info->func[2] = PMBUS_HAVE_VMON;
165	}
166
167	return pmbus_do_probe(client, info);
168}
169
170static const struct i2c_device_id lt7182s_id[] = {
171	{ "lt7182s" },
172	{}
173};
174MODULE_DEVICE_TABLE(i2c, lt7182s_id);
175
176static const struct of_device_id __maybe_unused lt7182s_of_match[] = {
177	{ .compatible = "adi,lt7182s" },
178	{}
179};
180
181static struct i2c_driver lt7182s_driver = {
182	.driver = {
183		.name = "lt7182s",
184		.of_match_table = of_match_ptr(lt7182s_of_match),
185	},
186	.probe = lt7182s_probe,
187	.id_table = lt7182s_id,
188};
189
190module_i2c_driver(lt7182s_driver);
191
192MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
193MODULE_DESCRIPTION("PMBus driver for Analog Devices LT7182S");
194MODULE_LICENSE("GPL");
195MODULE_IMPORT_NS("PMBUS");