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/bitops.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/err.h>
26#include <linux/i2c.h>
27#include "pmbus.h"
28
29#define MAX8688_MFR_VOUT_PEAK		0xd4
30#define MAX8688_MFR_IOUT_PEAK		0xd5
31#define MAX8688_MFR_TEMPERATURE_PEAK	0xd6
32#define MAX8688_MFG_STATUS		0xd8
33
34#define MAX8688_STATUS_OC_FAULT		BIT(4)
35#define MAX8688_STATUS_OV_FAULT		BIT(5)
36#define MAX8688_STATUS_OV_WARNING	BIT(8)
37#define MAX8688_STATUS_UV_FAULT		BIT(9)
38#define MAX8688_STATUS_UV_WARNING	BIT(10)
39#define MAX8688_STATUS_UC_FAULT		BIT(11)
40#define MAX8688_STATUS_OC_WARNING	BIT(12)
41#define MAX8688_STATUS_OT_FAULT		BIT(13)
42#define MAX8688_STATUS_OT_WARNING	BIT(14)
43
44static int max8688_read_word_data(struct i2c_client *client, int page, int reg)
45{
46	int ret;
47
48	if (page)
49		return -ENXIO;
50
51	switch (reg) {
52	case PMBUS_VIRT_READ_VOUT_MAX:
53		ret = pmbus_read_word_data(client, 0, MAX8688_MFR_VOUT_PEAK);
54		break;
55	case PMBUS_VIRT_READ_IOUT_MAX:
56		ret = pmbus_read_word_data(client, 0, MAX8688_MFR_IOUT_PEAK);
57		break;
58	case PMBUS_VIRT_READ_TEMP_MAX:
59		ret = pmbus_read_word_data(client, 0,
60					   MAX8688_MFR_TEMPERATURE_PEAK);
61		break;
62	case PMBUS_VIRT_RESET_VOUT_HISTORY:
63	case PMBUS_VIRT_RESET_IOUT_HISTORY:
64	case PMBUS_VIRT_RESET_TEMP_HISTORY:
65		ret = 0;
66		break;
67	default:
68		ret = -ENODATA;
69		break;
70	}
71	return ret;
72}
73
74static int max8688_write_word_data(struct i2c_client *client, int page, int reg,
75				   u16 word)
76{
77	int ret;
78
79	switch (reg) {
80	case PMBUS_VIRT_RESET_VOUT_HISTORY:
81		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_VOUT_PEAK,
82					    0);
83		break;
84	case PMBUS_VIRT_RESET_IOUT_HISTORY:
85		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_IOUT_PEAK,
86					    0);
87		break;
88	case PMBUS_VIRT_RESET_TEMP_HISTORY:
89		ret = pmbus_write_word_data(client, 0,
90					    MAX8688_MFR_TEMPERATURE_PEAK,
91					    0xffff);
92		break;
93	default:
94		ret = -ENODATA;
95		break;
96	}
97	return ret;
98}
99
100static int max8688_read_byte_data(struct i2c_client *client, int page, int reg)
101{
102	int ret = 0;
103	int mfg_status;
104
105	if (page > 0)
106		return -ENXIO;
107
108	switch (reg) {
109	case PMBUS_STATUS_VOUT:
110		mfg_status = pmbus_read_word_data(client, 0,
111						  MAX8688_MFG_STATUS);
112		if (mfg_status < 0)
113			return mfg_status;
114		if (mfg_status & MAX8688_STATUS_UV_WARNING)
115			ret |= PB_VOLTAGE_UV_WARNING;
116		if (mfg_status & MAX8688_STATUS_UV_FAULT)
117			ret |= PB_VOLTAGE_UV_FAULT;
118		if (mfg_status & MAX8688_STATUS_OV_WARNING)
119			ret |= PB_VOLTAGE_OV_WARNING;
120		if (mfg_status & MAX8688_STATUS_OV_FAULT)
121			ret |= PB_VOLTAGE_OV_FAULT;
122		break;
123	case PMBUS_STATUS_IOUT:
124		mfg_status = pmbus_read_word_data(client, 0,
125						  MAX8688_MFG_STATUS);
126		if (mfg_status < 0)
127			return mfg_status;
128		if (mfg_status & MAX8688_STATUS_UC_FAULT)
129			ret |= PB_IOUT_UC_FAULT;
130		if (mfg_status & MAX8688_STATUS_OC_WARNING)
131			ret |= PB_IOUT_OC_WARNING;
132		if (mfg_status & MAX8688_STATUS_OC_FAULT)
133			ret |= PB_IOUT_OC_FAULT;
134		break;
135	case PMBUS_STATUS_TEMPERATURE:
136		mfg_status = pmbus_read_word_data(client, 0,
137						  MAX8688_MFG_STATUS);
138		if (mfg_status < 0)
139			return mfg_status;
140		if (mfg_status & MAX8688_STATUS_OT_WARNING)
141			ret |= PB_TEMP_OT_WARNING;
142		if (mfg_status & MAX8688_STATUS_OT_FAULT)
143			ret |= PB_TEMP_OT_FAULT;
144		break;
145	default:
146		ret = -ENODATA;
147		break;
148	}
149	return ret;
150}
151
152static struct pmbus_driver_info max8688_info = {
153	.pages = 1,
154	.format[PSC_VOLTAGE_IN] = direct,
155	.format[PSC_VOLTAGE_OUT] = direct,
156	.format[PSC_TEMPERATURE] = direct,
157	.format[PSC_CURRENT_OUT] = direct,
158	.m[PSC_VOLTAGE_IN] = 19995,
159	.b[PSC_VOLTAGE_IN] = 0,
160	.R[PSC_VOLTAGE_IN] = -1,
161	.m[PSC_VOLTAGE_OUT] = 19995,
162	.b[PSC_VOLTAGE_OUT] = 0,
163	.R[PSC_VOLTAGE_OUT] = -1,
164	.m[PSC_CURRENT_OUT] = 23109,
165	.b[PSC_CURRENT_OUT] = 0,
166	.R[PSC_CURRENT_OUT] = -2,
167	.m[PSC_TEMPERATURE] = -7612,
168	.b[PSC_TEMPERATURE] = 335,
169	.R[PSC_TEMPERATURE] = -3,
170	.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP
171		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
172		| PMBUS_HAVE_STATUS_TEMP,
173	.read_byte_data = max8688_read_byte_data,
174	.read_word_data = max8688_read_word_data,
175	.write_word_data = max8688_write_word_data,
176};
177
178static int max8688_probe(struct i2c_client *client,
179			 const struct i2c_device_id *id)
180{
181	return pmbus_do_probe(client, id, &max8688_info);
182}
183
184static const struct i2c_device_id max8688_id[] = {
185	{"max8688", 0},
186	{ }
187};
188
189MODULE_DEVICE_TABLE(i2c, max8688_id);
190
191/* This is the driver that will be inserted */
192static struct i2c_driver max8688_driver = {
193	.driver = {
194		   .name = "max8688",
195		   },
196	.probe = max8688_probe,
197	.remove = pmbus_do_remove,
198	.id_table = max8688_id,
199};
200
201module_i2c_driver(max8688_driver);
202
203MODULE_AUTHOR("Guenter Roeck");
204MODULE_DESCRIPTION("PMBus driver for Maxim MAX8688");
205MODULE_LICENSE("GPL");
206