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
31struct mpq7932_data {
32	struct pmbus_driver_info info;
33	struct pmbus_platform_data pdata;
34};
35
36#if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
37static 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
53static 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
69static 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
96static 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
131static const struct of_device_id mpq7932_of_match[] = {
132	{ .compatible = "mps,mpq7932"},
133	{},
134};
135MODULE_DEVICE_TABLE(of, mpq7932_of_match);
136
137static const struct i2c_device_id mpq7932_id[] = {
138	{ "mpq7932", },
139	{ },
140};
141MODULE_DEVICE_TABLE(i2c, mpq7932_id);
142
143static 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};
151module_i2c_driver(mpq7932_regulator_driver);
152
153MODULE_AUTHOR("Saravanan Sekar <saravanan@linumiz.com>");
154MODULE_DESCRIPTION("MPQ7932 PMIC regulator driver");
155MODULE_LICENSE("GPL");
156MODULE_IMPORT_NS(PMBUS);
157