xref: /openbmc/linux/drivers/hwmon/pmbus/mpq7932.c (revision 6db6b729)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * mpq7932.c - hwmon with optional regulator driver for mps mpq7932
4  * Copyright 2022 Monolithic Power Systems, Inc
5  *
6  * Author: Saravanan Sekar <saravanan@linumiz.com>
7  */
8 
9 #include <linux/bits.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/pmbus.h>
17 #include "pmbus.h"
18 
19 #define MPQ7932_BUCK_UV_MIN		206250
20 #define MPQ7932_UV_STEP			6250
21 #define MPQ7932_N_VOLTAGES		256
22 #define MPQ7932_VOUT_MAX		0xFF
23 #define MPQ7932_NUM_PAGES		6
24 
25 #define MPQ7932_TON_DELAY		0x60
26 #define MPQ7932_VOUT_STARTUP_SLEW	0xA3
27 #define MPQ7932_VOUT_SHUTDOWN_SLEW	0xA5
28 #define MPQ7932_VOUT_SLEW_MASK		GENMASK(1, 0)
29 #define MPQ7932_TON_DELAY_MASK		GENMASK(4, 0)
30 
31 struct mpq7932_data {
32 	struct pmbus_driver_info info;
33 	struct pmbus_platform_data pdata;
34 };
35 
36 #if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
37 static struct regulator_desc mpq7932_regulators_desc[] = {
38 	PMBUS_REGULATOR_STEP("buck", 0, MPQ7932_N_VOLTAGES,
39 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
40 	PMBUS_REGULATOR_STEP("buck", 1, MPQ7932_N_VOLTAGES,
41 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
42 	PMBUS_REGULATOR_STEP("buck", 2, MPQ7932_N_VOLTAGES,
43 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
44 	PMBUS_REGULATOR_STEP("buck", 3, MPQ7932_N_VOLTAGES,
45 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
46 	PMBUS_REGULATOR_STEP("buck", 4, MPQ7932_N_VOLTAGES,
47 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
48 	PMBUS_REGULATOR_STEP("buck", 5, MPQ7932_N_VOLTAGES,
49 			     MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
50 };
51 #endif
52 
53 static int mpq7932_write_word_data(struct i2c_client *client, int page, int reg,
54 				   u16 word)
55 {
56 	switch (reg) {
57 	/*
58 	 * chip supports only byte access for VOUT_COMMAND otherwise
59 	 * access results -EREMOTEIO
60 	 */
61 	case PMBUS_VOUT_COMMAND:
62 		return pmbus_write_byte_data(client, page, reg, word & 0xFF);
63 
64 	default:
65 		return -ENODATA;
66 	}
67 }
68 
69 static int mpq7932_read_word_data(struct i2c_client *client, int page,
70 				  int phase, int reg)
71 {
72 	switch (reg) {
73 	/*
74 	 * chip supports neither (PMBUS_VOUT_MARGIN_HIGH, PMBUS_VOUT_MARGIN_LOW)
75 	 * nor (PMBUS_MFR_VOUT_MIN, PMBUS_MFR_VOUT_MAX). As a result set voltage
76 	 * fails due to error in pmbus_regulator_get_low_margin, so faked.
77 	 */
78 	case PMBUS_MFR_VOUT_MIN:
79 		return 0;
80 
81 	case PMBUS_MFR_VOUT_MAX:
82 		return MPQ7932_VOUT_MAX;
83 
84 	/*
85 	 * chip supports only byte access for VOUT_COMMAND otherwise
86 	 * access results in -EREMOTEIO
87 	 */
88 	case PMBUS_READ_VOUT:
89 		return pmbus_read_byte_data(client, page, PMBUS_VOUT_COMMAND);
90 
91 	default:
92 		return -ENODATA;
93 	}
94 }
95 
96 static int mpq7932_probe(struct i2c_client *client)
97 {
98 	struct mpq7932_data *data;
99 	struct pmbus_driver_info *info;
100 	struct device *dev = &client->dev;
101 	int i;
102 
103 	data = devm_kzalloc(dev, sizeof(struct mpq7932_data), GFP_KERNEL);
104 	if (!data)
105 		return -ENOMEM;
106 
107 	info = &data->info;
108 	info->pages = MPQ7932_NUM_PAGES;
109 	info->format[PSC_VOLTAGE_OUT] = direct;
110 	info->m[PSC_VOLTAGE_OUT] = 160;
111 	info->b[PSC_VOLTAGE_OUT] = -33;
112 	for (i = 0; i < info->pages; i++) {
113 		info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
114 				| PMBUS_HAVE_STATUS_TEMP;
115 	}
116 
117 #if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
118 	info->num_regulators = ARRAY_SIZE(mpq7932_regulators_desc);
119 	info->reg_desc = mpq7932_regulators_desc;
120 #endif
121 
122 	info->read_word_data = mpq7932_read_word_data;
123 	info->write_word_data = mpq7932_write_word_data;
124 
125 	data->pdata.flags = PMBUS_NO_CAPABILITY;
126 	dev->platform_data = &data->pdata;
127 
128 	return pmbus_do_probe(client, info);
129 }
130 
131 static const struct of_device_id mpq7932_of_match[] = {
132 	{ .compatible = "mps,mpq7932"},
133 	{},
134 };
135 MODULE_DEVICE_TABLE(of, mpq7932_of_match);
136 
137 static const struct i2c_device_id mpq7932_id[] = {
138 	{ "mpq7932", },
139 	{ },
140 };
141 MODULE_DEVICE_TABLE(i2c, mpq7932_id);
142 
143 static struct i2c_driver mpq7932_regulator_driver = {
144 	.driver = {
145 		.name = "mpq7932",
146 		.of_match_table = mpq7932_of_match,
147 	},
148 	.probe = mpq7932_probe,
149 	.id_table = mpq7932_id,
150 };
151 module_i2c_driver(mpq7932_regulator_driver);
152 
153 MODULE_AUTHOR("Saravanan Sekar <saravanan@linumiz.com>");
154 MODULE_DESCRIPTION("MPQ7932 PMIC regulator driver");
155 MODULE_LICENSE("GPL");
156 MODULE_IMPORT_NS(PMBUS);
157