1/*
2 * Hardware monitoring driver for Maxim MAX8688
3 *
4 * Copyright (c) 2011 Ericsson AB.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/err.h>
25#include <linux/i2c.h>
26#include "pmbus.h"
27
28#define MAX8688_MFR_VOUT_PEAK		0xd4
29#define MAX8688_MFR_IOUT_PEAK		0xd5
30#define MAX8688_MFR_TEMPERATURE_PEAK	0xd6
31#define MAX8688_MFG_STATUS		0xd8
32
33#define MAX8688_STATUS_OC_FAULT		(1 << 4)
34#define MAX8688_STATUS_OV_FAULT		(1 << 5)
35#define MAX8688_STATUS_OV_WARNING	(1 << 8)
36#define MAX8688_STATUS_UV_FAULT		(1 << 9)
37#define MAX8688_STATUS_UV_WARNING	(1 << 10)
38#define MAX8688_STATUS_UC_FAULT		(1 << 11)
39#define MAX8688_STATUS_OC_WARNING	(1 << 12)
40#define MAX8688_STATUS_OT_FAULT		(1 << 13)
41#define MAX8688_STATUS_OT_WARNING	(1 << 14)
42
43static int max8688_read_word_data(struct i2c_client *client, int page, int reg)
44{
45	int ret;
46
47	if (page)
48		return -ENXIO;
49
50	switch (reg) {
51	case PMBUS_VIRT_READ_VOUT_MAX:
52		ret = pmbus_read_word_data(client, 0, MAX8688_MFR_VOUT_PEAK);
53		break;
54	case PMBUS_VIRT_READ_IOUT_MAX:
55		ret = pmbus_read_word_data(client, 0, MAX8688_MFR_IOUT_PEAK);
56		break;
57	case PMBUS_VIRT_READ_TEMP_MAX:
58		ret = pmbus_read_word_data(client, 0,
59					   MAX8688_MFR_TEMPERATURE_PEAK);
60		break;
61	case PMBUS_VIRT_RESET_VOUT_HISTORY:
62	case PMBUS_VIRT_RESET_IOUT_HISTORY:
63	case PMBUS_VIRT_RESET_TEMP_HISTORY:
64		ret = 0;
65		break;
66	default:
67		ret = -ENODATA;
68		break;
69	}
70	return ret;
71}
72
73static int max8688_write_word_data(struct i2c_client *client, int page, int reg,
74				   u16 word)
75{
76	int ret;
77
78	switch (reg) {
79	case PMBUS_VIRT_RESET_VOUT_HISTORY:
80		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_VOUT_PEAK,
81					    0);
82		break;
83	case PMBUS_VIRT_RESET_IOUT_HISTORY:
84		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_IOUT_PEAK,
85					    0);
86		break;
87	case PMBUS_VIRT_RESET_TEMP_HISTORY:
88		ret = pmbus_write_word_data(client, 0,
89					    MAX8688_MFR_TEMPERATURE_PEAK,
90					    0xffff);
91		break;
92	default:
93		ret = -ENODATA;
94		break;
95	}
96	return ret;
97}
98
99static int max8688_read_byte_data(struct i2c_client *client, int page, int reg)
100{
101	int ret = 0;
102	int mfg_status;
103
104	if (page > 0)
105		return -ENXIO;
106
107	switch (reg) {
108	case PMBUS_STATUS_VOUT:
109		mfg_status = pmbus_read_word_data(client, 0,
110						  MAX8688_MFG_STATUS);
111		if (mfg_status < 0)
112			return mfg_status;
113		if (mfg_status & MAX8688_STATUS_UV_WARNING)
114			ret |= PB_VOLTAGE_UV_WARNING;
115		if (mfg_status & MAX8688_STATUS_UV_FAULT)
116			ret |= PB_VOLTAGE_UV_FAULT;
117		if (mfg_status & MAX8688_STATUS_OV_WARNING)
118			ret |= PB_VOLTAGE_OV_WARNING;
119		if (mfg_status & MAX8688_STATUS_OV_FAULT)
120			ret |= PB_VOLTAGE_OV_FAULT;
121		break;
122	case PMBUS_STATUS_IOUT:
123		mfg_status = pmbus_read_word_data(client, 0,
124						  MAX8688_MFG_STATUS);
125		if (mfg_status < 0)
126			return mfg_status;
127		if (mfg_status & MAX8688_STATUS_UC_FAULT)
128			ret |= PB_IOUT_UC_FAULT;
129		if (mfg_status & MAX8688_STATUS_OC_WARNING)
130			ret |= PB_IOUT_OC_WARNING;
131		if (mfg_status & MAX8688_STATUS_OC_FAULT)
132			ret |= PB_IOUT_OC_FAULT;
133		break;
134	case PMBUS_STATUS_TEMPERATURE:
135		mfg_status = pmbus_read_word_data(client, 0,
136						  MAX8688_MFG_STATUS);
137		if (mfg_status < 0)
138			return mfg_status;
139		if (mfg_status & MAX8688_STATUS_OT_WARNING)
140			ret |= PB_TEMP_OT_WARNING;
141		if (mfg_status & MAX8688_STATUS_OT_FAULT)
142			ret |= PB_TEMP_OT_FAULT;
143		break;
144	default:
145		ret = -ENODATA;
146		break;
147	}
148	return ret;
149}
150
151static struct pmbus_driver_info max8688_info = {
152	.pages = 1,
153	.format[PSC_VOLTAGE_IN] = direct,
154	.format[PSC_VOLTAGE_OUT] = direct,
155	.format[PSC_TEMPERATURE] = direct,
156	.format[PSC_CURRENT_OUT] = direct,
157	.m[PSC_VOLTAGE_IN] = 19995,
158	.b[PSC_VOLTAGE_IN] = 0,
159	.R[PSC_VOLTAGE_IN] = -1,
160	.m[PSC_VOLTAGE_OUT] = 19995,
161	.b[PSC_VOLTAGE_OUT] = 0,
162	.R[PSC_VOLTAGE_OUT] = -1,
163	.m[PSC_CURRENT_OUT] = 23109,
164	.b[PSC_CURRENT_OUT] = 0,
165	.R[PSC_CURRENT_OUT] = -2,
166	.m[PSC_TEMPERATURE] = -7612,
167	.b[PSC_TEMPERATURE] = 335,
168	.R[PSC_TEMPERATURE] = -3,
169	.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP
170		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
171		| PMBUS_HAVE_STATUS_TEMP,
172	.read_byte_data = max8688_read_byte_data,
173	.read_word_data = max8688_read_word_data,
174	.write_word_data = max8688_write_word_data,
175};
176
177static int max8688_probe(struct i2c_client *client,
178			 const struct i2c_device_id *id)
179{
180	return pmbus_do_probe(client, id, &max8688_info);
181}
182
183static const struct i2c_device_id max8688_id[] = {
184	{"max8688", 0},
185	{ }
186};
187
188MODULE_DEVICE_TABLE(i2c, max8688_id);
189
190/* This is the driver that will be inserted */
191static struct i2c_driver max8688_driver = {
192	.driver = {
193		   .name = "max8688",
194		   },
195	.probe = max8688_probe,
196	.remove = pmbus_do_remove,
197	.id_table = max8688_id,
198};
199
200module_i2c_driver(max8688_driver);
201
202MODULE_AUTHOR("Guenter Roeck");
203MODULE_DESCRIPTION("PMBus driver for Maxim MAX8688");
204MODULE_LICENSE("GPL");
205