1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Driver for MPS MP5990 Hot-Swap Controller
4 */
5
6 #include <linux/i2c.h>
7 #include <linux/module.h>
8 #include <linux/of_device.h>
9 #include "pmbus.h"
10
11 #define MP5990_EFUSE_CFG (0xC4)
12 #define MP5990_VOUT_FORMAT BIT(9)
13
14 struct mp5990_data {
15 struct pmbus_driver_info info;
16 u8 vout_mode;
17 u8 vout_linear_exponent;
18 };
19
20 #define to_mp5990_data(x) container_of(x, struct mp5990_data, info)
21
mp5990_read_byte_data(struct i2c_client * client,int page,int reg)22 static int mp5990_read_byte_data(struct i2c_client *client, int page, int reg)
23 {
24 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
25 struct mp5990_data *data = to_mp5990_data(info);
26
27 switch (reg) {
28 case PMBUS_VOUT_MODE:
29 if (data->vout_mode == linear) {
30 /*
31 * The VOUT format used by the chip is linear11,
32 * not linear16. Report that VOUT is in linear mode
33 * and return exponent value extracted while probing
34 * the chip.
35 */
36 return data->vout_linear_exponent;
37 }
38
39 /*
40 * The datasheet does not support the VOUT command,
41 * but the device responds with a default value of 0x17.
42 * In the standard, 0x17 represents linear mode.
43 * Therefore, we should report that VOUT is in direct
44 * format when the chip is configured for it.
45 */
46 return PB_VOUT_MODE_DIRECT;
47
48 default:
49 return -ENODATA;
50 }
51 }
52
mp5990_read_word_data(struct i2c_client * client,int page,int phase,int reg)53 static int mp5990_read_word_data(struct i2c_client *client, int page,
54 int phase, int reg)
55 {
56 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
57 struct mp5990_data *data = to_mp5990_data(info);
58 int ret;
59 s32 mantissa;
60
61 switch (reg) {
62 case PMBUS_READ_VOUT:
63 ret = pmbus_read_word_data(client, page, phase, reg);
64 if (ret < 0)
65 return ret;
66 /*
67 * Because the VOUT format used by the chip is linear11 and not
68 * linear16, we disregard bits[15:11]. The exponent is reported
69 * as part of the VOUT_MODE command.
70 */
71 if (data->vout_mode == linear) {
72 mantissa = ((s16)((ret & 0x7ff) << 5)) >> 5;
73 ret = mantissa;
74 }
75 break;
76 default:
77 return -ENODATA;
78 }
79
80 return ret;
81 }
82
83 static struct pmbus_driver_info mp5990_info = {
84 .pages = 1,
85 .format[PSC_VOLTAGE_IN] = direct,
86 .format[PSC_VOLTAGE_OUT] = direct,
87 .format[PSC_CURRENT_OUT] = direct,
88 .format[PSC_POWER] = direct,
89 .format[PSC_TEMPERATURE] = direct,
90 .m[PSC_VOLTAGE_IN] = 32,
91 .b[PSC_VOLTAGE_IN] = 0,
92 .R[PSC_VOLTAGE_IN] = 0,
93 .m[PSC_VOLTAGE_OUT] = 32,
94 .b[PSC_VOLTAGE_OUT] = 0,
95 .R[PSC_VOLTAGE_OUT] = 0,
96 .m[PSC_CURRENT_OUT] = 16,
97 .b[PSC_CURRENT_OUT] = 0,
98 .R[PSC_CURRENT_OUT] = 0,
99 .m[PSC_POWER] = 1,
100 .b[PSC_POWER] = 0,
101 .R[PSC_POWER] = 0,
102 .m[PSC_TEMPERATURE] = 1,
103 .b[PSC_TEMPERATURE] = 0,
104 .R[PSC_TEMPERATURE] = 0,
105 .func[0] =
106 PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN |
107 PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT |
108 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
109 .read_byte_data = mp5990_read_byte_data,
110 .read_word_data = mp5990_read_word_data,
111 };
112
mp5990_probe(struct i2c_client * client)113 static int mp5990_probe(struct i2c_client *client)
114 {
115 struct pmbus_driver_info *info;
116 struct mp5990_data *data;
117 int ret;
118
119 data = devm_kzalloc(&client->dev, sizeof(struct mp5990_data),
120 GFP_KERNEL);
121 if (!data)
122 return -ENOMEM;
123
124 memcpy(&data->info, &mp5990_info, sizeof(*info));
125 info = &data->info;
126
127 /* Read Vout Config */
128 ret = i2c_smbus_read_word_data(client, MP5990_EFUSE_CFG);
129 if (ret < 0) {
130 dev_err(&client->dev, "Can't get vout mode.");
131 return ret;
132 }
133
134 /*
135 * EFUSE_CFG (0xC4) bit9=1 is linear mode, bit=0 is direct mode.
136 */
137 if (ret & MP5990_VOUT_FORMAT) {
138 data->vout_mode = linear;
139 data->info.format[PSC_VOLTAGE_IN] = linear;
140 data->info.format[PSC_VOLTAGE_OUT] = linear;
141 data->info.format[PSC_CURRENT_OUT] = linear;
142 data->info.format[PSC_POWER] = linear;
143 ret = i2c_smbus_read_word_data(client, PMBUS_READ_VOUT);
144 if (ret < 0) {
145 dev_err(&client->dev, "Can't get vout exponent.");
146 return ret;
147 }
148 data->vout_linear_exponent = (u8)((ret >> 11) & 0x1f);
149 } else {
150 data->vout_mode = direct;
151 }
152 return pmbus_do_probe(client, info);
153 }
154
155 static const struct of_device_id mp5990_of_match[] = {
156 { .compatible = "mps,mp5990" },
157 {}
158 };
159
160 static const struct i2c_device_id mp5990_id[] = {
161 {"mp5990"},
162 { }
163 };
164 MODULE_DEVICE_TABLE(i2c, mp5990_id);
165
166 static struct i2c_driver mp5990_driver = {
167 .driver = {
168 .name = "mp5990",
169 .of_match_table = mp5990_of_match,
170 },
171 .probe = mp5990_probe,
172 .id_table = mp5990_id,
173 };
174 module_i2c_driver(mp5990_driver);
175
176 MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");
177 MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
178 MODULE_LICENSE("GPL");
179 MODULE_IMPORT_NS("PMBUS");
180