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		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
247		.of_match_table = rt6245_of_match_table,
248	},
249	.probe = rt6245_probe,
250};
251module_i2c_driver(rt6245_driver);
252
253MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
254MODULE_DESCRIPTION("Richtek RT6245 Regulator Driver");
255MODULE_LICENSE("GPL v2");
256