1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Hardware monitoring driver for Maxim MAX8688
4  *
5  * Copyright (c) 2011 Ericsson AB.
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/err.h>
13 #include <linux/i2c.h>
14 #include "pmbus.h"
15 
16 #define MAX8688_MFR_VOUT_PEAK		0xd4
17 #define MAX8688_MFR_IOUT_PEAK		0xd5
18 #define MAX8688_MFR_TEMPERATURE_PEAK	0xd6
19 #define MAX8688_MFG_STATUS		0xd8
20 
21 #define MAX8688_STATUS_OC_FAULT		BIT(4)
22 #define MAX8688_STATUS_OV_FAULT		BIT(5)
23 #define MAX8688_STATUS_OV_WARNING	BIT(8)
24 #define MAX8688_STATUS_UV_FAULT		BIT(9)
25 #define MAX8688_STATUS_UV_WARNING	BIT(10)
26 #define MAX8688_STATUS_UC_FAULT		BIT(11)
27 #define MAX8688_STATUS_OC_WARNING	BIT(12)
28 #define MAX8688_STATUS_OT_FAULT		BIT(13)
29 #define MAX8688_STATUS_OT_WARNING	BIT(14)
30 
max8688_read_word_data(struct i2c_client * client,int page,int phase,int reg)31 static int max8688_read_word_data(struct i2c_client *client, int page,
32 				  int phase, int reg)
33 {
34 	int ret;
35 
36 	if (page > 0)
37 		return -ENXIO;
38 
39 	switch (reg) {
40 	case PMBUS_VIRT_READ_VOUT_MAX:
41 		ret = pmbus_read_word_data(client, 0, 0xff,
42 					   MAX8688_MFR_VOUT_PEAK);
43 		break;
44 	case PMBUS_VIRT_READ_IOUT_MAX:
45 		ret = pmbus_read_word_data(client, 0, 0xff,
46 					   MAX8688_MFR_IOUT_PEAK);
47 		break;
48 	case PMBUS_VIRT_READ_TEMP_MAX:
49 		ret = pmbus_read_word_data(client, 0, 0xff,
50 					   MAX8688_MFR_TEMPERATURE_PEAK);
51 		break;
52 	case PMBUS_VIRT_RESET_VOUT_HISTORY:
53 	case PMBUS_VIRT_RESET_IOUT_HISTORY:
54 	case PMBUS_VIRT_RESET_TEMP_HISTORY:
55 		ret = 0;
56 		break;
57 	default:
58 		ret = -ENODATA;
59 		break;
60 	}
61 	return ret;
62 }
63 
max8688_write_word_data(struct i2c_client * client,int page,int reg,u16 word)64 static int max8688_write_word_data(struct i2c_client *client, int page, int reg,
65 				   u16 word)
66 {
67 	int ret;
68 
69 	switch (reg) {
70 	case PMBUS_VIRT_RESET_VOUT_HISTORY:
71 		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_VOUT_PEAK,
72 					    0);
73 		break;
74 	case PMBUS_VIRT_RESET_IOUT_HISTORY:
75 		ret = pmbus_write_word_data(client, 0, MAX8688_MFR_IOUT_PEAK,
76 					    0);
77 		break;
78 	case PMBUS_VIRT_RESET_TEMP_HISTORY:
79 		ret = pmbus_write_word_data(client, 0,
80 					    MAX8688_MFR_TEMPERATURE_PEAK,
81 					    0xffff);
82 		break;
83 	default:
84 		ret = -ENODATA;
85 		break;
86 	}
87 	return ret;
88 }
89 
max8688_read_byte_data(struct i2c_client * client,int page,int reg)90 static int max8688_read_byte_data(struct i2c_client *client, int page, int reg)
91 {
92 	int ret = 0;
93 	int mfg_status;
94 
95 	if (page > 0)
96 		return -ENXIO;
97 
98 	switch (reg) {
99 	case PMBUS_STATUS_VOUT:
100 		mfg_status = pmbus_read_word_data(client, 0, 0xff,
101 						  MAX8688_MFG_STATUS);
102 		if (mfg_status < 0)
103 			return mfg_status;
104 		if (mfg_status & MAX8688_STATUS_UV_WARNING)
105 			ret |= PB_VOLTAGE_UV_WARNING;
106 		if (mfg_status & MAX8688_STATUS_UV_FAULT)
107 			ret |= PB_VOLTAGE_UV_FAULT;
108 		if (mfg_status & MAX8688_STATUS_OV_WARNING)
109 			ret |= PB_VOLTAGE_OV_WARNING;
110 		if (mfg_status & MAX8688_STATUS_OV_FAULT)
111 			ret |= PB_VOLTAGE_OV_FAULT;
112 		break;
113 	case PMBUS_STATUS_IOUT:
114 		mfg_status = pmbus_read_word_data(client, 0, 0xff,
115 						  MAX8688_MFG_STATUS);
116 		if (mfg_status < 0)
117 			return mfg_status;
118 		if (mfg_status & MAX8688_STATUS_UC_FAULT)
119 			ret |= PB_IOUT_UC_FAULT;
120 		if (mfg_status & MAX8688_STATUS_OC_WARNING)
121 			ret |= PB_IOUT_OC_WARNING;
122 		if (mfg_status & MAX8688_STATUS_OC_FAULT)
123 			ret |= PB_IOUT_OC_FAULT;
124 		break;
125 	case PMBUS_STATUS_TEMPERATURE:
126 		mfg_status = pmbus_read_word_data(client, 0, 0xff,
127 						  MAX8688_MFG_STATUS);
128 		if (mfg_status < 0)
129 			return mfg_status;
130 		if (mfg_status & MAX8688_STATUS_OT_WARNING)
131 			ret |= PB_TEMP_OT_WARNING;
132 		if (mfg_status & MAX8688_STATUS_OT_FAULT)
133 			ret |= PB_TEMP_OT_FAULT;
134 		break;
135 	default:
136 		ret = -ENODATA;
137 		break;
138 	}
139 	return ret;
140 }
141 
142 static struct pmbus_driver_info max8688_info = {
143 	.pages = 1,
144 	.format[PSC_VOLTAGE_IN] = direct,
145 	.format[PSC_VOLTAGE_OUT] = direct,
146 	.format[PSC_TEMPERATURE] = direct,
147 	.format[PSC_CURRENT_OUT] = direct,
148 	.m[PSC_VOLTAGE_IN] = 19995,
149 	.b[PSC_VOLTAGE_IN] = 0,
150 	.R[PSC_VOLTAGE_IN] = -1,
151 	.m[PSC_VOLTAGE_OUT] = 19995,
152 	.b[PSC_VOLTAGE_OUT] = 0,
153 	.R[PSC_VOLTAGE_OUT] = -1,
154 	.m[PSC_CURRENT_OUT] = 23109,
155 	.b[PSC_CURRENT_OUT] = 0,
156 	.R[PSC_CURRENT_OUT] = -2,
157 	.m[PSC_TEMPERATURE] = -7612,
158 	.b[PSC_TEMPERATURE] = 335,
159 	.R[PSC_TEMPERATURE] = -3,
160 	.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP
161 		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
162 		| PMBUS_HAVE_STATUS_TEMP,
163 	.read_byte_data = max8688_read_byte_data,
164 	.read_word_data = max8688_read_word_data,
165 	.write_word_data = max8688_write_word_data,
166 };
167 
max8688_probe(struct i2c_client * client)168 static int max8688_probe(struct i2c_client *client)
169 {
170 	return pmbus_do_probe(client, &max8688_info);
171 }
172 
173 static const struct i2c_device_id max8688_id[] = {
174 	{"max8688", 0},
175 	{ }
176 };
177 
178 MODULE_DEVICE_TABLE(i2c, max8688_id);
179 
180 /* This is the driver that will be inserted */
181 static struct i2c_driver max8688_driver = {
182 	.driver = {
183 		   .name = "max8688",
184 		   },
185 	.probe_new = max8688_probe,
186 	.id_table = max8688_id,
187 };
188 
189 module_i2c_driver(max8688_driver);
190 
191 MODULE_AUTHOR("Guenter Roeck");
192 MODULE_DESCRIPTION("PMBus driver for Maxim MAX8688");
193 MODULE_LICENSE("GPL");
194 MODULE_IMPORT_NS(PMBUS);
195