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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rt6245-regulator.c (6840B)


      1// SPDX-License-Identifier: GPL-2.0+
      2
      3#include <linux/bitops.h>
      4#include <linux/delay.h>
      5#include <linux/gpio/consumer.h>
      6#include <linux/i2c.h>
      7#include <linux/kernel.h>
      8#include <linux/module.h>
      9#include <linux/regmap.h>
     10#include <linux/regulator/driver.h>
     11#include <linux/regulator/of_regulator.h>
     12
     13#define RT6245_VIRT_OCLIMIT	0x00
     14#define RT6245_VIRT_OTLEVEL	0x01
     15#define RT6245_VIRT_PGDLYTIME	0x02
     16#define RT6245_VIRT_SLEWRATE	0x03
     17#define RT6245_VIRT_SWFREQ	0x04
     18#define RT6245_VIRT_VOUT	0x05
     19
     20#define RT6245_VOUT_MASK	GENMASK(6, 0)
     21#define RT6245_SLEW_MASK	GENMASK(2, 0)
     22#define RT6245_CHKSUM_MASK	BIT(7)
     23#define RT6245_CODE_MASK	GENMASK(6, 0)
     24
     25/* HW Enable + Soft start time */
     26#define RT6245_ENTIME_IN_US	5000
     27
     28#define RT6245_VOUT_MINUV	437500
     29#define RT6245_VOUT_MAXUV	1387500
     30#define RT6245_VOUT_STEPUV	12500
     31#define RT6245_NUM_VOUT		((RT6245_VOUT_MAXUV - RT6245_VOUT_MINUV) / RT6245_VOUT_STEPUV + 1)
     32
     33struct rt6245_priv {
     34	struct gpio_desc *enable_gpio;
     35	bool enable_state;
     36};
     37
     38static int rt6245_enable(struct regulator_dev *rdev)
     39{
     40	struct rt6245_priv *priv = rdev_get_drvdata(rdev);
     41	struct regmap *regmap = rdev_get_regmap(rdev);
     42	int ret;
     43
     44	if (!priv->enable_gpio)
     45		return 0;
     46
     47	gpiod_direction_output(priv->enable_gpio, 1);
     48	usleep_range(RT6245_ENTIME_IN_US, RT6245_ENTIME_IN_US + 1000);
     49
     50	regcache_cache_only(regmap, false);
     51	ret = regcache_sync(regmap);
     52	if (ret)
     53		return ret;
     54
     55	priv->enable_state = true;
     56	return 0;
     57}
     58
     59static int rt6245_disable(struct regulator_dev *rdev)
     60{
     61	struct rt6245_priv *priv = rdev_get_drvdata(rdev);
     62	struct regmap *regmap = rdev_get_regmap(rdev);
     63
     64	if (!priv->enable_gpio)
     65		return -EINVAL;
     66
     67	regcache_cache_only(regmap, true);
     68	regcache_mark_dirty(regmap);
     69
     70	gpiod_direction_output(priv->enable_gpio, 0);
     71
     72	priv->enable_state = false;
     73	return 0;
     74}
     75
     76static int rt6245_is_enabled(struct regulator_dev *rdev)
     77{
     78	struct rt6245_priv *priv = rdev_get_drvdata(rdev);
     79
     80	return priv->enable_state ? 1 : 0;
     81}
     82
     83static const struct regulator_ops rt6245_regulator_ops = {
     84	.list_voltage = regulator_list_voltage_linear,
     85	.set_voltage_sel = regulator_set_voltage_sel_regmap,
     86	.get_voltage_sel = regulator_get_voltage_sel_regmap,
     87	.set_ramp_delay = regulator_set_ramp_delay_regmap,
     88	.enable = rt6245_enable,
     89	.disable = rt6245_disable,
     90	.is_enabled = rt6245_is_enabled,
     91};
     92
     93/* ramp delay dividend is 12500 uV/uS, and divisor from 1 to 8 */
     94static const unsigned int rt6245_ramp_delay_table[] = {
     95	12500, 6250, 4167, 3125, 2500, 2083, 1786, 1562
     96};
     97
     98static const struct regulator_desc rt6245_regulator_desc = {
     99	.name = "rt6245-regulator",
    100	.ops = &rt6245_regulator_ops,
    101	.type = REGULATOR_VOLTAGE,
    102	.min_uV = RT6245_VOUT_MINUV,
    103	.uV_step = RT6245_VOUT_STEPUV,
    104	.n_voltages = RT6245_NUM_VOUT,
    105	.ramp_delay_table = rt6245_ramp_delay_table,
    106	.n_ramp_values = ARRAY_SIZE(rt6245_ramp_delay_table),
    107	.owner = THIS_MODULE,
    108	.vsel_reg = RT6245_VIRT_VOUT,
    109	.vsel_mask = RT6245_VOUT_MASK,
    110	.ramp_reg = RT6245_VIRT_SLEWRATE,
    111	.ramp_mask = RT6245_SLEW_MASK,
    112};
    113
    114static int rt6245_init_device_properties(struct device *dev)
    115{
    116	const struct {
    117		const char *name;
    118		unsigned int reg;
    119	} rt6245_props[] = {
    120		{ "richtek,oc-level-select",  RT6245_VIRT_OCLIMIT },
    121		{ "richtek,ot-level-select", RT6245_VIRT_OTLEVEL },
    122		{ "richtek,pgdly-time-select", RT6245_VIRT_PGDLYTIME },
    123		{ "richtek,switch-freq-select", RT6245_VIRT_SWFREQ }
    124	};
    125	struct regmap *regmap = dev_get_regmap(dev, NULL);
    126	u8 propval;
    127	int i, ret;
    128
    129	for (i = 0; i < ARRAY_SIZE(rt6245_props); i++) {
    130		ret = device_property_read_u8(dev, rt6245_props[i].name, &propval);
    131		if (ret)
    132			continue;
    133
    134		ret = regmap_write(regmap, rt6245_props[i].reg, propval);
    135		if (ret) {
    136			dev_err(dev, "Fail to apply [%s:%d]\n", rt6245_props[i].name, propval);
    137			return ret;
    138		}
    139	}
    140
    141	return 0;
    142}
    143
    144static int rt6245_reg_write(void *context, unsigned int reg, unsigned int val)
    145{
    146	struct i2c_client *i2c = context;
    147	static const u8 func_base[] = { 0x6F, 0x73, 0x78, 0x61, 0x7C, 0 };
    148	unsigned int code, bit_count;
    149
    150	code = func_base[reg];
    151	code += val;
    152
    153	/* xor checksum for bit 6 to 0 */
    154	bit_count = hweight8(code & RT6245_CODE_MASK);
    155	if (bit_count % 2)
    156		code |= RT6245_CHKSUM_MASK;
    157	else
    158		code &= ~RT6245_CHKSUM_MASK;
    159
    160	return i2c_smbus_write_byte(i2c, code);
    161}
    162
    163static const struct reg_default rt6245_reg_defaults[] = {
    164	/* Default over current 14A */
    165	{ RT6245_VIRT_OCLIMIT, 2 },
    166	/* Default over temperature 150'c */
    167	{ RT6245_VIRT_OTLEVEL, 0 },
    168	/* Default power good delay time 10us */
    169	{ RT6245_VIRT_PGDLYTIME, 1 },
    170	/* Default slewrate 12.5mV/uS */
    171	{ RT6245_VIRT_SLEWRATE, 0 },
    172	/* Default switch frequency 800KHz */
    173	{ RT6245_VIRT_SWFREQ, 1 },
    174	/* Default voltage 750mV */
    175	{ RT6245_VIRT_VOUT, 0x19 }
    176};
    177
    178static const struct regmap_config rt6245_regmap_config = {
    179	.reg_bits = 8,
    180	.val_bits = 8,
    181	.max_register = RT6245_VIRT_VOUT,
    182	.cache_type = REGCACHE_FLAT,
    183	.reg_defaults = rt6245_reg_defaults,
    184	.num_reg_defaults = ARRAY_SIZE(rt6245_reg_defaults),
    185	.reg_write = rt6245_reg_write,
    186};
    187
    188static int rt6245_probe(struct i2c_client *i2c)
    189{
    190	struct rt6245_priv *priv;
    191	struct regmap *regmap;
    192	struct regulator_config regulator_cfg = {};
    193	struct regulator_dev *rdev;
    194	int ret;
    195
    196	priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
    197	if (!priv)
    198		return -ENOMEM;
    199
    200	priv->enable_state = true;
    201
    202	priv->enable_gpio = devm_gpiod_get_optional(&i2c->dev, "enable", GPIOD_OUT_HIGH);
    203	if (IS_ERR(priv->enable_gpio)) {
    204		dev_err(&i2c->dev, "Failed to get 'enable' gpio\n");
    205		return PTR_ERR(priv->enable_gpio);
    206	}
    207
    208	usleep_range(RT6245_ENTIME_IN_US, RT6245_ENTIME_IN_US + 1000);
    209
    210	regmap = devm_regmap_init(&i2c->dev, NULL, i2c, &rt6245_regmap_config);
    211	if (IS_ERR(regmap)) {
    212		dev_err(&i2c->dev, "Failed to initialize the regmap\n");
    213		return PTR_ERR(regmap);
    214	}
    215
    216	ret = rt6245_init_device_properties(&i2c->dev);
    217	if (ret) {
    218		dev_err(&i2c->dev, "Failed to initialize device properties\n");
    219		return ret;
    220	}
    221
    222	regulator_cfg.dev = &i2c->dev;
    223	regulator_cfg.of_node = i2c->dev.of_node;
    224	regulator_cfg.regmap = regmap;
    225	regulator_cfg.driver_data = priv;
    226	regulator_cfg.init_data = of_get_regulator_init_data(&i2c->dev, i2c->dev.of_node,
    227							     &rt6245_regulator_desc);
    228	rdev = devm_regulator_register(&i2c->dev, &rt6245_regulator_desc, &regulator_cfg);
    229	if (IS_ERR(rdev)) {
    230		dev_err(&i2c->dev, "Failed to register regulator\n");
    231		return PTR_ERR(rdev);
    232	}
    233
    234	return 0;
    235}
    236
    237static const struct of_device_id __maybe_unused rt6245_of_match_table[] = {
    238	{ .compatible = "richtek,rt6245", },
    239	{}
    240};
    241MODULE_DEVICE_TABLE(of, rt6245_of_match_table);
    242
    243static struct i2c_driver rt6245_driver = {
    244	.driver = {
    245		.name = "rt6245",
    246		.of_match_table = rt6245_of_match_table,
    247	},
    248	.probe_new = rt6245_probe,
    249};
    250module_i2c_driver(rt6245_driver);
    251
    252MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
    253MODULE_DESCRIPTION("Richtek RT6245 Regulator Driver");
    254MODULE_LICENSE("GPL v2");