xref: /openbmc/linux/drivers/hwmon/pmbus/pli1209bc.c (revision e7593bda)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Hardware monitoring driver for Vicor PLI1209BC Digital Supervisor
4  *
5  * Copyright (c) 2022 9elements GmbH
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/i2c.h>
10 #include <linux/module.h>
11 #include <linux/pmbus.h>
12 #include <linux/regulator/driver.h>
13 #include "pmbus.h"
14 
15 /*
16  * The capability command is only supported at page 0. Probing the device while
17  * the page register is set to 1 will falsely enable PEC support. Disable
18  * capability probing accordingly, since the PLI1209BC does not have any
19  * additional capabilities.
20  */
21 static struct pmbus_platform_data pli1209bc_plat_data = {
22 	.flags = PMBUS_NO_CAPABILITY,
23 };
24 
pli1209bc_read_word_data(struct i2c_client * client,int page,int phase,int reg)25 static int pli1209bc_read_word_data(struct i2c_client *client, int page,
26 				    int phase, int reg)
27 {
28 	int data;
29 
30 	switch (reg) {
31 	/* PMBUS_READ_POUT uses a direct format with R=0 */
32 	case PMBUS_READ_POUT:
33 		data = pmbus_read_word_data(client, page, phase, reg);
34 		if (data < 0)
35 			return data;
36 		data = sign_extend32(data, 15) * 10;
37 		return clamp_val(data, -32768, 32767) & 0xffff;
38 	/*
39 	 * PMBUS_READ_VOUT and PMBUS_READ_TEMPERATURE_1 return invalid data
40 	 * when the BCM is turned off. Since it is not possible to return
41 	 * ENODATA error, return zero instead.
42 	 */
43 	case PMBUS_READ_VOUT:
44 	case PMBUS_READ_TEMPERATURE_1:
45 		data = pmbus_read_word_data(client, page, phase,
46 					    PMBUS_STATUS_WORD);
47 		if (data < 0)
48 			return data;
49 		if (data & PB_STATUS_POWER_GOOD_N)
50 			return 0;
51 		return pmbus_read_word_data(client, page, phase, reg);
52 	default:
53 		return -ENODATA;
54 	}
55 }
56 
pli1209bc_write_byte(struct i2c_client * client,int page,u8 reg)57 static int pli1209bc_write_byte(struct i2c_client *client, int page, u8 reg)
58 {
59 	int ret;
60 
61 	switch (reg) {
62 	case PMBUS_CLEAR_FAULTS:
63 		ret = pmbus_write_byte(client, page, reg);
64 		/*
65 		 * PLI1209 takes 230 usec to execute the CLEAR_FAULTS command.
66 		 * During that time it's busy and NACKs all requests on the
67 		 * SMBUS interface. It also NACKs reads on PMBUS_STATUS_BYTE
68 		 * making it impossible to poll the BUSY flag.
69 		 *
70 		 * Just wait for not BUSY unconditionally.
71 		 */
72 		usleep_range(250, 300);
73 		break;
74 	default:
75 		ret = -ENODATA;
76 		break;
77 	}
78 	return ret;
79 }
80 
81 #if IS_ENABLED(CONFIG_SENSORS_PLI1209BC_REGULATOR)
82 static const struct regulator_desc pli1209bc_reg_desc = {
83 	.name = "vout2",
84 	.id = 1,
85 	.of_match = of_match_ptr("vout2"),
86 	.regulators_node = of_match_ptr("regulators"),
87 	.ops = &pmbus_regulator_ops,
88 	.type = REGULATOR_VOLTAGE,
89 	.owner = THIS_MODULE,
90 };
91 #endif
92 
93 static struct pmbus_driver_info pli1209bc_info = {
94 	.pages = 2,
95 	.format[PSC_VOLTAGE_IN] = direct,
96 	.format[PSC_VOLTAGE_OUT] = direct,
97 	.format[PSC_CURRENT_IN] = direct,
98 	.format[PSC_CURRENT_OUT] = direct,
99 	.format[PSC_POWER] = direct,
100 	.format[PSC_TEMPERATURE] = direct,
101 	.m[PSC_VOLTAGE_IN] = 1,
102 	.b[PSC_VOLTAGE_IN] = 0,
103 	.R[PSC_VOLTAGE_IN] = 1,
104 	.m[PSC_VOLTAGE_OUT] = 1,
105 	.b[PSC_VOLTAGE_OUT] = 0,
106 	.R[PSC_VOLTAGE_OUT] = 1,
107 	.m[PSC_CURRENT_IN] = 1,
108 	.b[PSC_CURRENT_IN] = 0,
109 	.R[PSC_CURRENT_IN] = 3,
110 	.m[PSC_CURRENT_OUT] = 1,
111 	.b[PSC_CURRENT_OUT] = 0,
112 	.R[PSC_CURRENT_OUT] = 2,
113 	.m[PSC_POWER] = 1,
114 	.b[PSC_POWER] = 0,
115 	.R[PSC_POWER] = 1,
116 	.m[PSC_TEMPERATURE] = 1,
117 	.b[PSC_TEMPERATURE] = 0,
118 	.R[PSC_TEMPERATURE] = 0,
119 	/*
120 	 * Page 0 sums up all attributes except voltage readings.
121 	 * The pli1209 digital supervisor only contains a single BCM, making
122 	 * page 0 redundant.
123 	 */
124 	.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT
125 	    | PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT
126 	    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
127 	    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
128 	    | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT,
129 	.read_word_data = pli1209bc_read_word_data,
130 	.write_byte = pli1209bc_write_byte,
131 #if IS_ENABLED(CONFIG_SENSORS_PLI1209BC_REGULATOR)
132 	.num_regulators = 1,
133 	.reg_desc = &pli1209bc_reg_desc,
134 #endif
135 };
136 
pli1209bc_probe(struct i2c_client * client)137 static int pli1209bc_probe(struct i2c_client *client)
138 {
139 	client->dev.platform_data = &pli1209bc_plat_data;
140 	return pmbus_do_probe(client, &pli1209bc_info);
141 }
142 
143 static const struct i2c_device_id pli1209bc_id[] = {
144 	{"pli1209bc", 0},
145 	{}
146 };
147 
148 MODULE_DEVICE_TABLE(i2c, pli1209bc_id);
149 
150 #ifdef CONFIG_OF
151 static const struct of_device_id pli1209bc_of_match[] = {
152 	{ .compatible = "vicor,pli1209bc" },
153 	{ },
154 };
155 MODULE_DEVICE_TABLE(of, pli1209bc_of_match);
156 #endif
157 
158 static struct i2c_driver pli1209bc_driver = {
159 	.driver = {
160 		   .name = "pli1209bc",
161 		   .of_match_table = of_match_ptr(pli1209bc_of_match),
162 		   },
163 	.probe = pli1209bc_probe,
164 	.id_table = pli1209bc_id,
165 };
166 
167 module_i2c_driver(pli1209bc_driver);
168 
169 MODULE_AUTHOR("Marcello Sylvester Bauer <sylv@sylv.io>");
170 MODULE_DESCRIPTION("PMBus driver for Vicor PLI1209BC");
171 MODULE_LICENSE("GPL");
172 MODULE_IMPORT_NS(PMBUS);
173