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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fixed.c (9174B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * fixed.c
      4 *
      5 * Copyright 2008 Wolfson Microelectronics PLC.
      6 *
      7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
      8 *
      9 * Copyright (c) 2009 Nokia Corporation
     10 * Roger Quadros <ext-roger.quadros@nokia.com>
     11 *
     12 * This is useful for systems with mixed controllable and
     13 * non-controllable regulators, as well as for allowing testing on
     14 * systems with no controllable regulators.
     15 */
     16
     17#include <linux/err.h>
     18#include <linux/mutex.h>
     19#include <linux/module.h>
     20#include <linux/platform_device.h>
     21#include <linux/pm_domain.h>
     22#include <linux/pm_opp.h>
     23#include <linux/regulator/driver.h>
     24#include <linux/regulator/fixed.h>
     25#include <linux/gpio/consumer.h>
     26#include <linux/slab.h>
     27#include <linux/of.h>
     28#include <linux/of_device.h>
     29#include <linux/regulator/of_regulator.h>
     30#include <linux/regulator/machine.h>
     31#include <linux/clk.h>
     32
     33
     34struct fixed_voltage_data {
     35	struct regulator_desc desc;
     36	struct regulator_dev *dev;
     37
     38	struct clk *enable_clock;
     39	unsigned int enable_counter;
     40	int performance_state;
     41};
     42
     43struct fixed_dev_type {
     44	bool has_enable_clock;
     45	bool has_performance_state;
     46};
     47
     48static int reg_clock_enable(struct regulator_dev *rdev)
     49{
     50	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
     51	int ret = 0;
     52
     53	ret = clk_prepare_enable(priv->enable_clock);
     54	if (ret)
     55		return ret;
     56
     57	priv->enable_counter++;
     58
     59	return ret;
     60}
     61
     62static int reg_clock_disable(struct regulator_dev *rdev)
     63{
     64	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
     65
     66	clk_disable_unprepare(priv->enable_clock);
     67	priv->enable_counter--;
     68
     69	return 0;
     70}
     71
     72static int reg_domain_enable(struct regulator_dev *rdev)
     73{
     74	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
     75	struct device *dev = rdev->dev.parent;
     76	int ret;
     77
     78	ret = dev_pm_genpd_set_performance_state(dev, priv->performance_state);
     79	if (ret)
     80		return ret;
     81
     82	priv->enable_counter++;
     83
     84	return ret;
     85}
     86
     87static int reg_domain_disable(struct regulator_dev *rdev)
     88{
     89	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
     90	struct device *dev = rdev->dev.parent;
     91	int ret;
     92
     93	ret = dev_pm_genpd_set_performance_state(dev, 0);
     94	if (ret)
     95		return ret;
     96
     97	priv->enable_counter--;
     98
     99	return 0;
    100}
    101
    102static int reg_is_enabled(struct regulator_dev *rdev)
    103{
    104	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
    105
    106	return priv->enable_counter > 0;
    107}
    108
    109
    110/**
    111 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
    112 * @dev: device requesting for fixed_voltage_config
    113 * @desc: regulator description
    114 *
    115 * Populates fixed_voltage_config structure by extracting data from device
    116 * tree node, returns a pointer to the populated structure of NULL if memory
    117 * alloc fails.
    118 */
    119static struct fixed_voltage_config *
    120of_get_fixed_voltage_config(struct device *dev,
    121			    const struct regulator_desc *desc)
    122{
    123	struct fixed_voltage_config *config;
    124	struct device_node *np = dev->of_node;
    125	struct regulator_init_data *init_data;
    126
    127	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
    128								 GFP_KERNEL);
    129	if (!config)
    130		return ERR_PTR(-ENOMEM);
    131
    132	config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
    133	if (!config->init_data)
    134		return ERR_PTR(-EINVAL);
    135
    136	init_data = config->init_data;
    137	init_data->constraints.apply_uV = 0;
    138
    139	config->supply_name = init_data->constraints.name;
    140	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
    141		config->microvolts = init_data->constraints.min_uV;
    142	} else {
    143		dev_err(dev,
    144			 "Fixed regulator specified with variable voltages\n");
    145		return ERR_PTR(-EINVAL);
    146	}
    147
    148	if (init_data->constraints.boot_on)
    149		config->enabled_at_boot = true;
    150
    151	of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
    152	of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
    153
    154	if (of_find_property(np, "vin-supply", NULL))
    155		config->input_supply = "vin";
    156
    157	return config;
    158}
    159
    160static const struct regulator_ops fixed_voltage_ops = {
    161};
    162
    163static const struct regulator_ops fixed_voltage_clkenabled_ops = {
    164	.enable = reg_clock_enable,
    165	.disable = reg_clock_disable,
    166	.is_enabled = reg_is_enabled,
    167};
    168
    169static const struct regulator_ops fixed_voltage_domain_ops = {
    170	.enable = reg_domain_enable,
    171	.disable = reg_domain_disable,
    172	.is_enabled = reg_is_enabled,
    173};
    174
    175static int reg_fixed_voltage_probe(struct platform_device *pdev)
    176{
    177	struct device *dev = &pdev->dev;
    178	struct fixed_voltage_config *config;
    179	struct fixed_voltage_data *drvdata;
    180	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
    181	struct regulator_config cfg = { };
    182	enum gpiod_flags gflags;
    183	int ret;
    184
    185	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
    186			       GFP_KERNEL);
    187	if (!drvdata)
    188		return -ENOMEM;
    189
    190	if (pdev->dev.of_node) {
    191		config = of_get_fixed_voltage_config(&pdev->dev,
    192						     &drvdata->desc);
    193		if (IS_ERR(config))
    194			return PTR_ERR(config);
    195	} else {
    196		config = dev_get_platdata(&pdev->dev);
    197	}
    198
    199	if (!config)
    200		return -ENOMEM;
    201
    202	drvdata->desc.name = devm_kstrdup(&pdev->dev,
    203					  config->supply_name,
    204					  GFP_KERNEL);
    205	if (drvdata->desc.name == NULL) {
    206		dev_err(&pdev->dev, "Failed to allocate supply name\n");
    207		return -ENOMEM;
    208	}
    209	drvdata->desc.type = REGULATOR_VOLTAGE;
    210	drvdata->desc.owner = THIS_MODULE;
    211
    212	if (drvtype && drvtype->has_enable_clock) {
    213		drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
    214
    215		drvdata->enable_clock = devm_clk_get(dev, NULL);
    216		if (IS_ERR(drvdata->enable_clock)) {
    217			dev_err(dev, "Can't get enable-clock from devicetree\n");
    218			return -ENOENT;
    219		}
    220	} else if (drvtype && drvtype->has_performance_state) {
    221		drvdata->desc.ops = &fixed_voltage_domain_ops;
    222
    223		drvdata->performance_state = of_get_required_opp_performance_state(dev->of_node, 0);
    224		if (drvdata->performance_state < 0) {
    225			dev_err(dev, "Can't get performance state from devicetree\n");
    226			return drvdata->performance_state;
    227		}
    228	} else {
    229		drvdata->desc.ops = &fixed_voltage_ops;
    230	}
    231
    232	drvdata->desc.enable_time = config->startup_delay;
    233	drvdata->desc.off_on_delay = config->off_on_delay;
    234
    235	if (config->input_supply) {
    236		drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
    237					    config->input_supply,
    238					    GFP_KERNEL);
    239		if (!drvdata->desc.supply_name)
    240			return -ENOMEM;
    241	}
    242
    243	if (config->microvolts)
    244		drvdata->desc.n_voltages = 1;
    245
    246	drvdata->desc.fixed_uV = config->microvolts;
    247
    248	/*
    249	 * The signal will be inverted by the GPIO core if flagged so in the
    250	 * descriptor.
    251	 */
    252	if (config->enabled_at_boot)
    253		gflags = GPIOD_OUT_HIGH;
    254	else
    255		gflags = GPIOD_OUT_LOW;
    256
    257	/*
    258	 * Some fixed regulators share the enable line between two
    259	 * regulators which makes it necessary to get a handle on the
    260	 * same descriptor for two different consumers. This will get
    261	 * the GPIO descriptor, but only the first call will initialize
    262	 * it so any flags such as inversion or open drain will only
    263	 * be set up by the first caller and assumed identical on the
    264	 * next caller.
    265	 *
    266	 * FIXME: find a better way to deal with this.
    267	 */
    268	gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
    269
    270	/*
    271	 * Do not use devm* here: the regulator core takes over the
    272	 * lifecycle management of the GPIO descriptor.
    273	 */
    274	cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
    275	if (IS_ERR(cfg.ena_gpiod))
    276		return dev_err_probe(&pdev->dev, PTR_ERR(cfg.ena_gpiod),
    277				     "can't get GPIO\n");
    278
    279	cfg.dev = &pdev->dev;
    280	cfg.init_data = config->init_data;
    281	cfg.driver_data = drvdata;
    282	cfg.of_node = pdev->dev.of_node;
    283
    284	drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
    285					       &cfg);
    286	if (IS_ERR(drvdata->dev)) {
    287		ret = dev_err_probe(&pdev->dev, PTR_ERR(drvdata->dev),
    288				    "Failed to register regulator: %ld\n",
    289				    PTR_ERR(drvdata->dev));
    290		return ret;
    291	}
    292
    293	platform_set_drvdata(pdev, drvdata);
    294
    295	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
    296		drvdata->desc.fixed_uV);
    297
    298	return 0;
    299}
    300
    301#if defined(CONFIG_OF)
    302static const struct fixed_dev_type fixed_voltage_data = {
    303	.has_enable_clock = false,
    304};
    305
    306static const struct fixed_dev_type fixed_clkenable_data = {
    307	.has_enable_clock = true,
    308};
    309
    310static const struct fixed_dev_type fixed_domain_data = {
    311	.has_performance_state = true,
    312};
    313
    314static const struct of_device_id fixed_of_match[] = {
    315	{
    316		.compatible = "regulator-fixed",
    317		.data = &fixed_voltage_data,
    318	},
    319	{
    320		.compatible = "regulator-fixed-clock",
    321		.data = &fixed_clkenable_data,
    322	},
    323	{
    324		.compatible = "regulator-fixed-domain",
    325		.data = &fixed_domain_data,
    326	},
    327	{
    328	},
    329};
    330MODULE_DEVICE_TABLE(of, fixed_of_match);
    331#endif
    332
    333static struct platform_driver regulator_fixed_voltage_driver = {
    334	.probe		= reg_fixed_voltage_probe,
    335	.driver		= {
    336		.name		= "reg-fixed-voltage",
    337		.of_match_table = of_match_ptr(fixed_of_match),
    338	},
    339};
    340
    341static int __init regulator_fixed_voltage_init(void)
    342{
    343	return platform_driver_register(&regulator_fixed_voltage_driver);
    344}
    345subsys_initcall(regulator_fixed_voltage_init);
    346
    347static void __exit regulator_fixed_voltage_exit(void)
    348{
    349	platform_driver_unregister(&regulator_fixed_voltage_driver);
    350}
    351module_exit(regulator_fixed_voltage_exit);
    352
    353MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
    354MODULE_DESCRIPTION("Fixed voltage regulator");
    355MODULE_LICENSE("GPL");
    356MODULE_ALIAS("platform:reg-fixed-voltage");