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
15enum chips { bpa_rs600, bpd_rs600 };
16
17static 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 */
47static 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 */
72static 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
88static 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
128static 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
149static const struct i2c_device_id bpa_rs600_id[] = {
150	{ "bpa-rs600", bpa_rs600 },
151	{ "bpd-rs600", bpd_rs600 },
152	{},
153};
154MODULE_DEVICE_TABLE(i2c, bpa_rs600_id);
155
156static 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
188static const struct of_device_id __maybe_unused bpa_rs600_of_match[] = {
189	{ .compatible = "blutek,bpa-rs600" },
190	{},
191};
192MODULE_DEVICE_TABLE(of, bpa_rs600_of_match);
193
194static 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
203module_i2c_driver(bpa_rs600_driver);
204
205MODULE_AUTHOR("Chris Packham");
206MODULE_DESCRIPTION("PMBus driver for BluTek BPA-RS600");
207MODULE_LICENSE("GPL");
208MODULE_IMPORT_NS(PMBUS);
209