1 /*
2  * TI TPS65132 Regulator driver
3  *
4  * Copyright (C) 2017 NVIDIA CORPORATION. All rights reserved.
5  *
6  * Author: Venkat Reddy Talla <vreddytalla@nvidia.com>
7  *		Laxman Dewangan <ldewangan@nvidia.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
15  * whether express or implied; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  */
19 
20 #include <linux/delay.h>
21 #include <linux/err.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/i2c.h>
24 #include <linux/module.h>
25 #include <linux/regmap.h>
26 #include <linux/regulator/driver.h>
27 #include <linux/regulator/machine.h>
28 
29 #define TPS65132_REG_VPOS		0x00
30 #define TPS65132_REG_VNEG		0x01
31 #define TPS65132_REG_APPS_DISP_DISN	0x03
32 #define TPS65132_REG_CONTROL		0x0FF
33 
34 #define TPS65132_VOUT_MASK		0x1F
35 #define TPS65132_VOUT_N_VOLTAGE		0x15
36 #define TPS65132_VOUT_VMIN		4000000
37 #define TPS65132_VOUT_VMAX		6000000
38 #define TPS65132_VOUT_STEP		100000
39 
40 #define TPS65132_REG_APPS_DIS_VPOS		BIT(0)
41 #define TPS65132_REG_APPS_DIS_VNEG		BIT(1)
42 
43 #define TPS65132_REGULATOR_ID_VPOS	0
44 #define TPS65132_REGULATOR_ID_VNEG	1
45 #define TPS65132_MAX_REGULATORS		2
46 
47 #define TPS65132_ACT_DIS_TIME_SLACK		1000
48 
49 struct tps65132_reg_pdata {
50 	struct gpio_desc *en_gpiod;
51 	struct gpio_desc *act_dis_gpiod;
52 	unsigned int act_dis_time_us;
53 	int ena_gpio_state;
54 };
55 
56 struct tps65132_regulator {
57 	struct device *dev;
58 	struct tps65132_reg_pdata reg_pdata[TPS65132_MAX_REGULATORS];
59 };
60 
61 static int tps65132_regulator_enable(struct regulator_dev *rdev)
62 {
63 	struct tps65132_regulator *tps = rdev_get_drvdata(rdev);
64 	int id = rdev_get_id(rdev);
65 	struct tps65132_reg_pdata *rpdata = &tps->reg_pdata[id];
66 	int ret;
67 
68 	if (!IS_ERR(rpdata->en_gpiod)) {
69 		gpiod_set_value_cansleep(rpdata->en_gpiod, 1);
70 		rpdata->ena_gpio_state = 1;
71 	}
72 
73 	/* Hardware automatically enable discharge bit in enable */
74 	if (rdev->constraints->active_discharge ==
75 			REGULATOR_ACTIVE_DISCHARGE_DISABLE) {
76 		ret = regulator_set_active_discharge_regmap(rdev, false);
77 		if (ret < 0) {
78 			dev_err(tps->dev, "Failed to disable active discharge: %d\n",
79 				ret);
80 			return ret;
81 		}
82 	}
83 
84 	return 0;
85 }
86 
87 static int tps65132_regulator_disable(struct regulator_dev *rdev)
88 {
89 	struct tps65132_regulator *tps = rdev_get_drvdata(rdev);
90 	int id = rdev_get_id(rdev);
91 	struct tps65132_reg_pdata *rpdata = &tps->reg_pdata[id];
92 
93 	if (!IS_ERR(rpdata->en_gpiod)) {
94 		gpiod_set_value_cansleep(rpdata->en_gpiod, 0);
95 		rpdata->ena_gpio_state = 0;
96 	}
97 
98 	if (!IS_ERR(rpdata->act_dis_gpiod)) {
99 		gpiod_set_value_cansleep(rpdata->act_dis_gpiod, 1);
100 		usleep_range(rpdata->act_dis_time_us, rpdata->act_dis_time_us +
101 			     TPS65132_ACT_DIS_TIME_SLACK);
102 		gpiod_set_value_cansleep(rpdata->act_dis_gpiod, 0);
103 	}
104 
105 	return 0;
106 }
107 
108 static int tps65132_regulator_is_enabled(struct regulator_dev *rdev)
109 {
110 	struct tps65132_regulator *tps = rdev_get_drvdata(rdev);
111 	int id = rdev_get_id(rdev);
112 	struct tps65132_reg_pdata *rpdata = &tps->reg_pdata[id];
113 
114 	if (!IS_ERR(rpdata->en_gpiod))
115 		return rpdata->ena_gpio_state;
116 
117 	return 1;
118 }
119 
120 static const struct regulator_ops tps65132_regulator_ops = {
121 	.enable = tps65132_regulator_enable,
122 	.disable = tps65132_regulator_disable,
123 	.is_enabled = tps65132_regulator_is_enabled,
124 	.list_voltage = regulator_list_voltage_linear,
125 	.map_voltage = regulator_map_voltage_linear,
126 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
127 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
128 	.set_active_discharge = regulator_set_active_discharge_regmap,
129 };
130 
131 static int tps65132_of_parse_cb(struct device_node *np,
132 				const struct regulator_desc *desc,
133 				struct regulator_config *config)
134 {
135 	struct tps65132_regulator *tps = config->driver_data;
136 	struct tps65132_reg_pdata *rpdata = &tps->reg_pdata[desc->id];
137 	int ret;
138 
139 	rpdata->en_gpiod = devm_fwnode_get_index_gpiod_from_child(tps->dev,
140 					"enable", 0, &np->fwnode, 0, "enable");
141 	if (IS_ERR_OR_NULL(rpdata->en_gpiod)) {
142 		ret = PTR_ERR(rpdata->en_gpiod);
143 
144 		/* Ignore the error other than probe defer */
145 		if (ret == -EPROBE_DEFER)
146 			return ret;
147 		return 0;
148 	}
149 
150 	rpdata->act_dis_gpiod = devm_fwnode_get_index_gpiod_from_child(
151 					tps->dev, "active-discharge", 0,
152 					&np->fwnode, 0, "active-discharge");
153 	if (IS_ERR_OR_NULL(rpdata->act_dis_gpiod)) {
154 		ret = PTR_ERR(rpdata->act_dis_gpiod);
155 
156 		/* Ignore the error other than probe defer */
157 		if (ret == -EPROBE_DEFER)
158 			return ret;
159 
160 		return 0;
161 	}
162 
163 	ret = of_property_read_u32(np, "ti,active-discharge-time-us",
164 				   &rpdata->act_dis_time_us);
165 	if (ret < 0) {
166 		dev_err(tps->dev, "Failed to read active discharge time:%d\n",
167 			ret);
168 		return ret;
169 	}
170 
171 	return 0;
172 }
173 
174 #define TPS65132_REGULATOR_DESC(_id, _name)		\
175 	[TPS65132_REGULATOR_ID_##_id] = {		\
176 		.name = "tps65132-"#_name,		\
177 		.supply_name = "vin",			\
178 		.id = TPS65132_REGULATOR_ID_##_id,	\
179 		.of_match = of_match_ptr(#_name),	\
180 		.of_parse_cb	= tps65132_of_parse_cb,	\
181 		.ops = &tps65132_regulator_ops,		\
182 		.n_voltages = TPS65132_VOUT_N_VOLTAGE,	\
183 		.min_uV = TPS65132_VOUT_VMIN,		\
184 		.uV_step = TPS65132_VOUT_STEP,		\
185 		.enable_time = 500,			\
186 		.vsel_mask = TPS65132_VOUT_MASK,	\
187 		.vsel_reg = TPS65132_REG_##_id,		\
188 		.active_discharge_off = 0,			\
189 		.active_discharge_on = TPS65132_REG_APPS_DIS_##_id, \
190 		.active_discharge_mask = TPS65132_REG_APPS_DIS_##_id, \
191 		.active_discharge_reg = TPS65132_REG_APPS_DISP_DISN, \
192 		.type = REGULATOR_VOLTAGE,		\
193 		.owner = THIS_MODULE,			\
194 	}
195 
196 static const struct regulator_desc tps_regs_desc[TPS65132_MAX_REGULATORS] = {
197 	TPS65132_REGULATOR_DESC(VPOS, outp),
198 	TPS65132_REGULATOR_DESC(VNEG, outn),
199 };
200 
201 static const struct regmap_range tps65132_no_reg_ranges[] = {
202 	regmap_reg_range(TPS65132_REG_APPS_DISP_DISN + 1,
203 			 TPS65132_REG_CONTROL - 1),
204 };
205 
206 static const struct regmap_access_table tps65132_no_reg_table = {
207 	.no_ranges = tps65132_no_reg_ranges,
208 	.n_no_ranges = ARRAY_SIZE(tps65132_no_reg_ranges),
209 };
210 
211 static const struct regmap_config tps65132_regmap_config = {
212 	.reg_bits	= 8,
213 	.val_bits	= 8,
214 	.max_register	= TPS65132_REG_CONTROL,
215 	.cache_type	= REGCACHE_NONE,
216 	.rd_table	= &tps65132_no_reg_table,
217 	.wr_table	= &tps65132_no_reg_table,
218 };
219 
220 static int tps65132_probe(struct i2c_client *client,
221 			  const struct i2c_device_id *client_id)
222 {
223 	struct device *dev = &client->dev;
224 	struct tps65132_regulator *tps;
225 	struct regulator_dev *rdev;
226 	struct regmap *rmap;
227 	struct regulator_config config = { };
228 	int id;
229 	int ret;
230 
231 	tps = devm_kzalloc(dev, sizeof(*tps), GFP_KERNEL);
232 	if (!tps)
233 		return -ENOMEM;
234 
235 	rmap = devm_regmap_init_i2c(client, &tps65132_regmap_config);
236 	if (IS_ERR(rmap)) {
237 		ret = PTR_ERR(rmap);
238 		dev_err(dev, "regmap init failed: %d\n", ret);
239 		return ret;
240 	}
241 
242 	i2c_set_clientdata(client, tps);
243 	tps->dev = dev;
244 
245 	for (id = 0; id < TPS65132_MAX_REGULATORS; ++id) {
246 		config.regmap = rmap;
247 		config.dev = dev;
248 		config.driver_data = tps;
249 
250 		rdev = devm_regulator_register(dev, &tps_regs_desc[id],
251 					       &config);
252 		if (IS_ERR(rdev)) {
253 			ret = PTR_ERR(rdev);
254 			dev_err(dev, "regulator %s register failed: %d\n",
255 				tps_regs_desc[id].name, ret);
256 			return ret;
257 		}
258 	}
259 	return 0;
260 }
261 
262 static const struct i2c_device_id tps65132_id[] = {
263 	{.name = "tps65132",},
264 	{},
265 };
266 MODULE_DEVICE_TABLE(i2c, tps65132_id);
267 
268 static struct i2c_driver tps65132_i2c_driver = {
269 	.driver = {
270 		.name = "tps65132",
271 	},
272 	.probe = tps65132_probe,
273 	.id_table = tps65132_id,
274 };
275 
276 module_i2c_driver(tps65132_i2c_driver);
277 
278 MODULE_DESCRIPTION("tps65132 regulator driver");
279 MODULE_AUTHOR("Venkat Reddy Talla <vreddytalla@nvidia.com>");
280 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
281 MODULE_LICENSE("GPL v2");
282