1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Hardware monitoring driver for BluTek BPA-RS600 Power Supplies
4 *
5 * Copyright 2021 Allied Telesis Labs
6 */
7
8 #include <linux/i2c.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/pmbus.h>
13 #include "pmbus.h"
14
15 enum chips { bpa_rs600, bpd_rs600 };
16
bpa_rs600_read_byte_data(struct i2c_client * client,int page,int reg)17 static int bpa_rs600_read_byte_data(struct i2c_client *client, int page, int reg)
18 {
19 int ret;
20
21 if (page > 0)
22 return -ENXIO;
23
24 switch (reg) {
25 case PMBUS_FAN_CONFIG_12:
26 /*
27 * Two fans are reported in PMBUS_FAN_CONFIG_12 but there is
28 * only one fan in the module. Mask out the FAN2 bits.
29 */
30 ret = pmbus_read_byte_data(client, 0, PMBUS_FAN_CONFIG_12);
31 if (ret >= 0)
32 ret &= ~(PB_FAN_2_INSTALLED | PB_FAN_2_PULSE_MASK);
33 break;
34 default:
35 ret = -ENODATA;
36 break;
37 }
38
39 return ret;
40 }
41
42 /*
43 * The BPA-RS600 violates the PMBus spec. Specifically it treats the
44 * mantissa as unsigned. Deal with this here to allow the PMBus core
45 * to work with correctly encoded data.
46 */
bpa_rs600_read_vin(struct i2c_client * client)47 static int bpa_rs600_read_vin(struct i2c_client *client)
48 {
49 int ret, exponent, mantissa;
50
51 ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_READ_VIN);
52 if (ret < 0)
53 return ret;
54
55 if (ret & BIT(10)) {
56 exponent = ret >> 11;
57 mantissa = ret & 0x7ff;
58
59 exponent++;
60 mantissa >>= 1;
61
62 ret = (exponent << 11) | mantissa;
63 }
64
65 return ret;
66 }
67
68 /*
69 * Firmware V5.70 incorrectly reports 1640W for MFR_PIN_MAX.
70 * Deal with this by returning a sensible value.
71 */
bpa_rs600_read_pin_max(struct i2c_client * client)72 static int bpa_rs600_read_pin_max(struct i2c_client *client)
73 {
74 int ret;
75
76 ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
77 if (ret < 0)
78 return ret;
79
80 /* Detect invalid 1640W (linear encoding) */
81 if (ret == 0x0b34)
82 /* Report 700W (linear encoding) */
83 return 0x095e;
84
85 return ret;
86 }
87
bpa_rs600_read_word_data(struct i2c_client * client,int page,int phase,int reg)88 static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
89 {
90 int ret;
91
92 if (page > 0)
93 return -ENXIO;
94
95 switch (reg) {
96 case PMBUS_VIN_UV_WARN_LIMIT:
97 case PMBUS_VIN_OV_WARN_LIMIT:
98 case PMBUS_VOUT_UV_WARN_LIMIT:
99 case PMBUS_VOUT_OV_WARN_LIMIT:
100 case PMBUS_IIN_OC_WARN_LIMIT:
101 case PMBUS_IOUT_OC_WARN_LIMIT:
102 case PMBUS_PIN_OP_WARN_LIMIT:
103 case PMBUS_POUT_OP_WARN_LIMIT:
104 case PMBUS_VIN_UV_FAULT_LIMIT:
105 case PMBUS_VIN_OV_FAULT_LIMIT:
106 case PMBUS_VOUT_UV_FAULT_LIMIT:
107 case PMBUS_VOUT_OV_FAULT_LIMIT:
108 /* These commands return data but it is invalid/un-documented */
109 ret = -ENXIO;
110 break;
111 case PMBUS_READ_VIN:
112 ret = bpa_rs600_read_vin(client);
113 break;
114 case PMBUS_MFR_PIN_MAX:
115 ret = bpa_rs600_read_pin_max(client);
116 break;
117 default:
118 if (reg >= PMBUS_VIRT_BASE)
119 ret = -ENXIO;
120 else
121 ret = -ENODATA;
122 break;
123 }
124
125 return ret;
126 }
127
128 static struct pmbus_driver_info bpa_rs600_info = {
129 .pages = 1,
130 .format[PSC_VOLTAGE_IN] = linear,
131 .format[PSC_VOLTAGE_OUT] = linear,
132 .format[PSC_CURRENT_IN] = linear,
133 .format[PSC_CURRENT_OUT] = linear,
134 .format[PSC_POWER] = linear,
135 .format[PSC_TEMPERATURE] = linear,
136 .format[PSC_FAN] = linear,
137 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
138 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT |
139 PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
140 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
141 PMBUS_HAVE_FAN12 |
142 PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
143 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
144 PMBUS_HAVE_STATUS_FAN12,
145 .read_byte_data = bpa_rs600_read_byte_data,
146 .read_word_data = bpa_rs600_read_word_data,
147 };
148
149 static const struct i2c_device_id bpa_rs600_id[] = {
150 { "bpa-rs600", bpa_rs600 },
151 { "bpd-rs600", bpd_rs600 },
152 {},
153 };
154 MODULE_DEVICE_TABLE(i2c, bpa_rs600_id);
155
bpa_rs600_probe(struct i2c_client * client)156 static int bpa_rs600_probe(struct i2c_client *client)
157 {
158 struct device *dev = &client->dev;
159 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
160 int ret;
161 const struct i2c_device_id *mid;
162
163 if (!i2c_check_functionality(client->adapter,
164 I2C_FUNC_SMBUS_READ_BYTE_DATA
165 | I2C_FUNC_SMBUS_READ_WORD_DATA
166 | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
167 return -ENODEV;
168
169 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
170 if (ret < 0) {
171 dev_err(dev, "Failed to read Manufacturer Model\n");
172 return ret;
173 }
174
175 for (mid = bpa_rs600_id; mid->name[0]; mid++) {
176 if (!strncasecmp(buf, mid->name, strlen(mid->name)))
177 break;
178 }
179 if (!mid->name[0]) {
180 buf[ret] = '\0';
181 dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
182 return -ENODEV;
183 }
184
185 return pmbus_do_probe(client, &bpa_rs600_info);
186 }
187
188 static const struct of_device_id __maybe_unused bpa_rs600_of_match[] = {
189 { .compatible = "blutek,bpa-rs600" },
190 {},
191 };
192 MODULE_DEVICE_TABLE(of, bpa_rs600_of_match);
193
194 static struct i2c_driver bpa_rs600_driver = {
195 .driver = {
196 .name = "bpa-rs600",
197 .of_match_table = of_match_ptr(bpa_rs600_of_match),
198 },
199 .probe = bpa_rs600_probe,
200 .id_table = bpa_rs600_id,
201 };
202
203 module_i2c_driver(bpa_rs600_driver);
204
205 MODULE_AUTHOR("Chris Packham");
206 MODULE_DESCRIPTION("PMBus driver for BluTek BPA-RS600");
207 MODULE_LICENSE("GPL");
208 MODULE_IMPORT_NS(PMBUS);
209