cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sy8106a-regulator.c (4065B)

      1// SPDX-License-Identifier: GPL-2.0+
      2//
      3// sy8106a-regulator.c - Regulator device driver for SY8106A
      4//
      5// Copyright (C) 2016 Ondřej Jirman <megous@megous.com>
      6// Copyright (c) 2017-2018 Icenowy Zheng <icenowy@aosc.io>
      7
      8#include <linux/err.h>
      9#include <linux/i2c.h>
     10#include <linux/module.h>
     11#include <linux/regmap.h>
     12#include <linux/regulator/driver.h>
     13#include <linux/regulator/of_regulator.h>
     14
     15#define SY8106A_REG_VOUT1_SEL		0x01
     16#define SY8106A_REG_VOUT_COM		0x02
     17#define SY8106A_REG_VOUT1_SEL_MASK	0x7f
     18#define SY8106A_DISABLE_REG		BIT(0)
     19/*
     20 * The I2C controlled voltage will only work when this bit is set; otherwise
     21 * it will behave like a fixed regulator.
     22 */
     23#define SY8106A_GO_BIT			BIT(7)
     24
     25static const struct regmap_config sy8106a_regmap_config = {
     26	.reg_bits = 8,
     27	.val_bits = 8,
     28};
     29
     30static const struct regulator_ops sy8106a_ops = {
     31	.set_voltage_sel = regulator_set_voltage_sel_regmap,
     32	.set_voltage_time_sel = regulator_set_voltage_time_sel,
     33	.get_voltage_sel = regulator_get_voltage_sel_regmap,
     34	.list_voltage = regulator_list_voltage_linear,
     35	/* Enabling/disabling the regulator is not yet implemented */
     36};
     37
     38/* Default limits measured in millivolts */
     39#define SY8106A_MIN_MV		680
     40#define SY8106A_MAX_MV		1950
     41#define SY8106A_STEP_MV		10
     42
     43static const struct regulator_desc sy8106a_reg = {
     44	.name = "SY8106A",
     45	.id = 0,
     46	.ops = &sy8106a_ops,
     47	.type = REGULATOR_VOLTAGE,
     48	.n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / SY8106A_STEP_MV) + 1,
     49	.min_uV = (SY8106A_MIN_MV * 1000),
     50	.uV_step = (SY8106A_STEP_MV * 1000),
     51	.vsel_reg = SY8106A_REG_VOUT1_SEL,
     52	.vsel_mask = SY8106A_REG_VOUT1_SEL_MASK,
     53	/*
     54	 * This ramp_delay is a conservative default value which works on
     55	 * H3/H5 boards VDD-CPUX situations.
     56	 */
     57	.ramp_delay = 200,
     58	.owner = THIS_MODULE,
     59};
     60
     61/*
     62 * I2C driver interface functions
     63 */
     64static int sy8106a_i2c_probe(struct i2c_client *i2c)
     65{
     66	struct device *dev = &i2c->dev;
     67	struct regulator_dev *rdev;
     68	struct regulator_config config = { };
     69	struct regmap *regmap;
     70	unsigned int reg, vsel;
     71	u32 fixed_voltage;
     72	int error;
     73
     74	error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt",
     75				     &fixed_voltage);
     76	if (error)
     77		return error;
     78
     79	if (fixed_voltage < SY8106A_MIN_MV * 1000 ||
     80	    fixed_voltage > SY8106A_MAX_MV * 1000)
     81		return -EINVAL;
     82
     83	regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config);
     84	if (IS_ERR(regmap)) {
     85		error = PTR_ERR(regmap);
     86		dev_err(dev, "Failed to allocate register map: %d\n", error);
     87		return error;
     88	}
     89
     90	config.dev = &i2c->dev;
     91	config.regmap = regmap;
     92
     93	config.of_node = dev->of_node;
     94	config.init_data = of_get_regulator_init_data(dev, dev->of_node,
     95						      &sy8106a_reg);
     96
     97	if (!config.init_data)
     98		return -ENOMEM;
     99
    100	/* Ensure GO_BIT is enabled when probing */
    101	error = regmap_read(regmap, SY8106A_REG_VOUT1_SEL, &reg);
    102	if (error)
    103		return error;
    104
    105	if (!(reg & SY8106A_GO_BIT)) {
    106		vsel = (fixed_voltage / 1000 - SY8106A_MIN_MV) /
    107		       SY8106A_STEP_MV;
    108
    109		error = regmap_write(regmap, SY8106A_REG_VOUT1_SEL,
    110				     vsel | SY8106A_GO_BIT);
    111		if (error)
    112			return error;
    113	}
    114
    115	/* Probe regulator */
    116	rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config);
    117	if (IS_ERR(rdev)) {
    118		error = PTR_ERR(rdev);
    119		dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error);
    120		return error;
    121	}
    122
    123	return 0;
    124}
    125
    126static const struct of_device_id __maybe_unused sy8106a_i2c_of_match[] = {
    127	{ .compatible = "silergy,sy8106a" },
    128	{ },
    129};
    130MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match);
    131
    132static const struct i2c_device_id sy8106a_i2c_id[] = {
    133	{ "sy8106a", 0 },
    134	{ },
    135};
    136MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id);
    137
    138static struct i2c_driver sy8106a_regulator_driver = {
    139	.driver = {
    140		.name = "sy8106a",
    141		.of_match_table	= of_match_ptr(sy8106a_i2c_of_match),
    142	},
    143	.probe_new = sy8106a_i2c_probe,
    144	.id_table = sy8106a_i2c_id,
    145};
    146
    147module_i2c_driver(sy8106a_regulator_driver);
    148
    149MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>");
    150MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
    151MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A");
    152MODULE_LICENSE("GPL");