1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tps51632-regulator.c -- TI TPS51632
4  *
5  * Regulator driver for TPS51632 3-2-1 Phase D-Cap Step Down Driverless
6  * Controller with serial VID control and DVFS.
7  *
8  * Copyright (c) 2012, NVIDIA Corporation.
9  *
10  * Author: Laxman Dewangan <ldewangan@nvidia.com>
11  */
12 
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/platform_device.h>
21 #include <linux/regmap.h>
22 #include <linux/regulator/driver.h>
23 #include <linux/regulator/machine.h>
24 #include <linux/regulator/of_regulator.h>
25 #include <linux/regulator/tps51632-regulator.h>
26 #include <linux/slab.h>
27 
28 /* Register definitions */
29 #define TPS51632_VOLTAGE_SELECT_REG		0x0
30 #define TPS51632_VOLTAGE_BASE_REG		0x1
31 #define TPS51632_OFFSET_REG			0x2
32 #define TPS51632_IMON_REG			0x3
33 #define TPS51632_VMAX_REG			0x4
34 #define TPS51632_DVFS_CONTROL_REG		0x5
35 #define TPS51632_POWER_STATE_REG		0x6
36 #define TPS51632_SLEW_REGS			0x7
37 #define TPS51632_FAULT_REG			0x14
38 
39 #define TPS51632_MAX_REG			0x15
40 
41 #define TPS51632_VOUT_MASK			0x7F
42 #define TPS51632_VOUT_OFFSET_MASK		0x1F
43 #define TPS51632_VMAX_MASK			0x7F
44 #define TPS51632_VMAX_LOCK			0x80
45 
46 /* TPS51632_DVFS_CONTROL_REG */
47 #define TPS51632_DVFS_PWMEN			0x1
48 #define TPS51632_DVFS_STEP_20			0x2
49 #define TPS51632_DVFS_VMAX_PG			0x4
50 #define TPS51632_DVFS_PWMRST			0x8
51 #define TPS51632_DVFS_OCA_EN			0x10
52 #define TPS51632_DVFS_FCCM			0x20
53 
54 /* TPS51632_POWER_STATE_REG */
55 #define TPS51632_POWER_STATE_MASK		0x03
56 #define TPS51632_POWER_STATE_MULTI_PHASE_CCM	0x0
57 #define TPS51632_POWER_STATE_SINGLE_PHASE_CCM	0x1
58 #define TPS51632_POWER_STATE_SINGLE_PHASE_DCM	0x2
59 
60 #define TPS51632_MIN_VOLTAGE			500000
61 #define TPS51632_MAX_VOLTAGE			1520000
62 #define TPS51632_VOLTAGE_STEP_10mV		10000
63 #define TPS51632_VOLTAGE_STEP_20mV		20000
64 #define TPS51632_MAX_VSEL			0x7F
65 #define TPS51632_MIN_VSEL			0x19
66 #define TPS51632_DEFAULT_RAMP_DELAY		6000
67 #define TPS51632_VOLT_VSEL(uV)					\
68 		(DIV_ROUND_UP(uV - TPS51632_MIN_VOLTAGE,	\
69 			TPS51632_VOLTAGE_STEP_10mV) +		\
70 			TPS51632_MIN_VSEL)
71 
72 /* TPS51632 chip information */
73 struct tps51632_chip {
74 	struct device *dev;
75 	struct regulator_desc desc;
76 	struct regulator_dev *rdev;
77 	struct regmap *regmap;
78 };
79 
80 static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
81 		int ramp_delay)
82 {
83 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
84 	int bit;
85 	int ret;
86 
87 	if (ramp_delay == 0)
88 		bit = 0;
89 	else
90 		bit = DIV_ROUND_UP(ramp_delay, 6000) - 1;
91 
92 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
93 	if (ret < 0)
94 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
95 	return ret;
96 }
97 
98 static const struct regulator_ops tps51632_dcdc_ops = {
99 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
100 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
101 	.list_voltage		= regulator_list_voltage_linear,
102 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
103 	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
104 };
105 
106 static int tps51632_init_dcdc(struct tps51632_chip *tps,
107 		struct tps51632_regulator_platform_data *pdata)
108 {
109 	int ret;
110 	uint8_t	control = 0;
111 	int vsel;
112 
113 	if (!pdata->enable_pwm_dvfs)
114 		goto skip_pwm_config;
115 
116 	control |= TPS51632_DVFS_PWMEN;
117 	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
118 	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
119 	if (ret < 0) {
120 		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
121 		return ret;
122 	}
123 
124 	if (pdata->dvfs_step_20mV)
125 		control |= TPS51632_DVFS_STEP_20;
126 
127 	if (pdata->max_voltage_uV) {
128 		unsigned int vmax;
129 		/**
130 		 * TPS51632 hw behavior: VMAX register can be write only
131 		 * once as it get locked after first write. The lock get
132 		 * reset only when device is power-reset.
133 		 * Write register only when lock bit is not enabled.
134 		 */
135 		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
136 		if (ret < 0) {
137 			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
138 			return ret;
139 		}
140 		if (!(vmax & TPS51632_VMAX_LOCK)) {
141 			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
142 			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
143 					vsel);
144 			if (ret < 0) {
145 				dev_err(tps->dev,
146 					"VMAX write failed, err %d\n", ret);
147 				return ret;
148 			}
149 		}
150 	}
151 
152 skip_pwm_config:
153 	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
154 	if (ret < 0)
155 		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
156 	return ret;
157 }
158 
159 static bool is_volatile_reg(struct device *dev, unsigned int reg)
160 {
161 	switch (reg) {
162 	case TPS51632_OFFSET_REG:
163 	case TPS51632_FAULT_REG:
164 	case TPS51632_IMON_REG:
165 		return true;
166 	default:
167 		return false;
168 	}
169 }
170 
171 static bool is_read_reg(struct device *dev, unsigned int reg)
172 {
173 	switch (reg) {
174 	case 0x08 ... 0x0F:
175 		return false;
176 	default:
177 		return true;
178 	}
179 }
180 
181 static bool is_write_reg(struct device *dev, unsigned int reg)
182 {
183 	switch (reg) {
184 	case TPS51632_VOLTAGE_SELECT_REG:
185 	case TPS51632_VOLTAGE_BASE_REG:
186 	case TPS51632_VMAX_REG:
187 	case TPS51632_DVFS_CONTROL_REG:
188 	case TPS51632_POWER_STATE_REG:
189 	case TPS51632_SLEW_REGS:
190 		return true;
191 	default:
192 		return false;
193 	}
194 }
195 
196 static const struct regmap_config tps51632_regmap_config = {
197 	.reg_bits		= 8,
198 	.val_bits		= 8,
199 	.writeable_reg		= is_write_reg,
200 	.readable_reg		= is_read_reg,
201 	.volatile_reg		= is_volatile_reg,
202 	.max_register		= TPS51632_MAX_REG - 1,
203 	.cache_type		= REGCACHE_RBTREE,
204 };
205 
206 #if defined(CONFIG_OF)
207 static const struct of_device_id tps51632_of_match[] = {
208 	{ .compatible = "ti,tps51632",},
209 	{},
210 };
211 MODULE_DEVICE_TABLE(of, tps51632_of_match);
212 
213 static struct tps51632_regulator_platform_data *
214 	of_get_tps51632_platform_data(struct device *dev,
215 				      const struct regulator_desc *desc)
216 {
217 	struct tps51632_regulator_platform_data *pdata;
218 	struct device_node *np = dev->of_node;
219 
220 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
221 	if (!pdata)
222 		return NULL;
223 
224 	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node,
225 							  desc);
226 	if (!pdata->reg_init_data) {
227 		dev_err(dev, "Not able to get OF regulator init data\n");
228 		return NULL;
229 	}
230 
231 	pdata->enable_pwm_dvfs =
232 			of_property_read_bool(np, "ti,enable-pwm-dvfs");
233 	pdata->dvfs_step_20mV = of_property_read_bool(np, "ti,dvfs-step-20mV");
234 
235 	pdata->base_voltage_uV = pdata->reg_init_data->constraints.min_uV ? :
236 					TPS51632_MIN_VOLTAGE;
237 	pdata->max_voltage_uV = pdata->reg_init_data->constraints.max_uV ? :
238 					TPS51632_MAX_VOLTAGE;
239 	return pdata;
240 }
241 #else
242 static struct tps51632_regulator_platform_data *
243 	of_get_tps51632_platform_data(struct device *dev,
244 				      const struct regulator_desc *desc)
245 {
246 	return NULL;
247 }
248 #endif
249 
250 static int tps51632_probe(struct i2c_client *client)
251 {
252 	struct tps51632_regulator_platform_data *pdata;
253 	struct regulator_dev *rdev;
254 	struct tps51632_chip *tps;
255 	int ret;
256 	struct regulator_config config = { };
257 
258 	if (client->dev.of_node) {
259 		const struct of_device_id *match;
260 		match = of_match_device(of_match_ptr(tps51632_of_match),
261 				&client->dev);
262 		if (!match) {
263 			dev_err(&client->dev, "Error: No device match found\n");
264 			return -ENODEV;
265 		}
266 	}
267 
268 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
269 	if (!tps)
270 		return -ENOMEM;
271 
272 	tps->dev = &client->dev;
273 	tps->desc.name = client->name;
274 	tps->desc.id = 0;
275 	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
276 	tps->desc.min_uV = TPS51632_MIN_VOLTAGE;
277 	tps->desc.uV_step = TPS51632_VOLTAGE_STEP_10mV;
278 	tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
279 	tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
280 	tps->desc.ops = &tps51632_dcdc_ops;
281 	tps->desc.type = REGULATOR_VOLTAGE;
282 	tps->desc.owner = THIS_MODULE;
283 
284 	pdata = dev_get_platdata(&client->dev);
285 	if (!pdata && client->dev.of_node)
286 		pdata = of_get_tps51632_platform_data(&client->dev, &tps->desc);
287 	if (!pdata) {
288 		dev_err(&client->dev, "No Platform data\n");
289 		return -EINVAL;
290 	}
291 
292 	if (pdata->enable_pwm_dvfs) {
293 		if ((pdata->base_voltage_uV < TPS51632_MIN_VOLTAGE) ||
294 		    (pdata->base_voltage_uV > TPS51632_MAX_VOLTAGE)) {
295 			dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
296 			return -EINVAL;
297 		}
298 
299 		if ((pdata->max_voltage_uV) &&
300 		    ((pdata->max_voltage_uV < TPS51632_MIN_VOLTAGE) ||
301 		     (pdata->max_voltage_uV > TPS51632_MAX_VOLTAGE))) {
302 			dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
303 			return -EINVAL;
304 		}
305 	}
306 
307 	if (pdata->enable_pwm_dvfs)
308 		tps->desc.vsel_reg = TPS51632_VOLTAGE_BASE_REG;
309 	else
310 		tps->desc.vsel_reg = TPS51632_VOLTAGE_SELECT_REG;
311 	tps->desc.vsel_mask = TPS51632_VOUT_MASK;
312 
313 	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
314 	if (IS_ERR(tps->regmap)) {
315 		ret = PTR_ERR(tps->regmap);
316 		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
317 		return ret;
318 	}
319 	i2c_set_clientdata(client, tps);
320 
321 	ret = tps51632_init_dcdc(tps, pdata);
322 	if (ret < 0) {
323 		dev_err(tps->dev, "Init failed, err = %d\n", ret);
324 		return ret;
325 	}
326 
327 	/* Register the regulators */
328 	config.dev = &client->dev;
329 	config.init_data = pdata->reg_init_data;
330 	config.driver_data = tps;
331 	config.regmap = tps->regmap;
332 	config.of_node = client->dev.of_node;
333 
334 	rdev = devm_regulator_register(&client->dev, &tps->desc, &config);
335 	if (IS_ERR(rdev)) {
336 		dev_err(tps->dev, "regulator register failed\n");
337 		return PTR_ERR(rdev);
338 	}
339 
340 	tps->rdev = rdev;
341 	return 0;
342 }
343 
344 static const struct i2c_device_id tps51632_id[] = {
345 	{.name = "tps51632",},
346 	{},
347 };
348 
349 MODULE_DEVICE_TABLE(i2c, tps51632_id);
350 
351 static struct i2c_driver tps51632_i2c_driver = {
352 	.driver = {
353 		.name = "tps51632",
354 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
355 		.of_match_table = of_match_ptr(tps51632_of_match),
356 	},
357 	.probe = tps51632_probe,
358 	.id_table = tps51632_id,
359 };
360 
361 static int __init tps51632_init(void)
362 {
363 	return i2c_add_driver(&tps51632_i2c_driver);
364 }
365 subsys_initcall(tps51632_init);
366 
367 static void __exit tps51632_cleanup(void)
368 {
369 	i2c_del_driver(&tps51632_i2c_driver);
370 }
371 module_exit(tps51632_cleanup);
372 
373 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
374 MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
375 MODULE_LICENSE("GPL v2");
376