1 /*
2  * tps51632-regulator.c -- TI TPS51632
3  *
4  * Regulator driver for TPS51632 3-2-1 Phase D-Cap Step Down Driverless
5  * Controller with serial VID control and DVFS.
6  *
7  * Copyright (c) 2012, NVIDIA Corporation.
8  *
9  * Author: Laxman Dewangan <ldewangan@nvidia.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation version 2.
14  *
15  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
16  * whether express or implied; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23  * 02111-1307, USA
24  */
25 
26 #include <linux/err.h>
27 #include <linux/i2c.h>
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/platform_device.h>
34 #include <linux/regmap.h>
35 #include <linux/regulator/driver.h>
36 #include <linux/regulator/machine.h>
37 #include <linux/regulator/of_regulator.h>
38 #include <linux/regulator/tps51632-regulator.h>
39 #include <linux/slab.h>
40 
41 /* Register definitions */
42 #define TPS51632_VOLTAGE_SELECT_REG		0x0
43 #define TPS51632_VOLTAGE_BASE_REG		0x1
44 #define TPS51632_OFFSET_REG			0x2
45 #define TPS51632_IMON_REG			0x3
46 #define TPS51632_VMAX_REG			0x4
47 #define TPS51632_DVFS_CONTROL_REG		0x5
48 #define TPS51632_POWER_STATE_REG		0x6
49 #define TPS51632_SLEW_REGS			0x7
50 #define TPS51632_FAULT_REG			0x14
51 
52 #define TPS51632_MAX_REG			0x15
53 
54 #define TPS51632_VOUT_MASK			0x7F
55 #define TPS51632_VOUT_OFFSET_MASK		0x1F
56 #define TPS51632_VMAX_MASK			0x7F
57 #define TPS51632_VMAX_LOCK			0x80
58 
59 /* TPS51632_DVFS_CONTROL_REG */
60 #define TPS51632_DVFS_PWMEN			0x1
61 #define TPS51632_DVFS_STEP_20			0x2
62 #define TPS51632_DVFS_VMAX_PG			0x4
63 #define TPS51632_DVFS_PWMRST			0x8
64 #define TPS51632_DVFS_OCA_EN			0x10
65 #define TPS51632_DVFS_FCCM			0x20
66 
67 /* TPS51632_POWER_STATE_REG */
68 #define TPS51632_POWER_STATE_MASK		0x03
69 #define TPS51632_POWER_STATE_MULTI_PHASE_CCM	0x0
70 #define TPS51632_POWER_STATE_SINGLE_PHASE_CCM	0x1
71 #define TPS51632_POWER_STATE_SINGLE_PHASE_DCM	0x2
72 
73 #define TPS51632_MIN_VOLATGE			500000
74 #define TPS51632_MAX_VOLATGE			1520000
75 #define TPS51632_VOLATGE_STEP_10mV		10000
76 #define TPS51632_VOLATGE_STEP_20mV		20000
77 #define TPS51632_MAX_VSEL			0x7F
78 #define TPS51632_MIN_VSEL			0x19
79 #define TPS51632_DEFAULT_RAMP_DELAY		6000
80 #define TPS51632_VOLT_VSEL(uV)					\
81 		(DIV_ROUND_UP(uV - TPS51632_MIN_VOLATGE,	\
82 			TPS51632_VOLATGE_STEP_10mV) +		\
83 			TPS51632_MIN_VSEL)
84 
85 /* TPS51632 chip information */
86 struct tps51632_chip {
87 	struct device *dev;
88 	struct regulator_desc desc;
89 	struct regulator_dev *rdev;
90 	struct regmap *regmap;
91 };
92 
93 static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
94 		int ramp_delay)
95 {
96 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
97 	int bit = ramp_delay/6000;
98 	int ret;
99 
100 	if (bit)
101 		bit--;
102 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
103 	if (ret < 0)
104 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
105 	return ret;
106 }
107 
108 static struct regulator_ops tps51632_dcdc_ops = {
109 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
110 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
111 	.list_voltage		= regulator_list_voltage_linear,
112 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
113 	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
114 };
115 
116 static int tps51632_init_dcdc(struct tps51632_chip *tps,
117 		struct tps51632_regulator_platform_data *pdata)
118 {
119 	int ret;
120 	uint8_t	control = 0;
121 	int vsel;
122 
123 	if (!pdata->enable_pwm_dvfs)
124 		goto skip_pwm_config;
125 
126 	control |= TPS51632_DVFS_PWMEN;
127 	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
128 	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
129 	if (ret < 0) {
130 		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
131 		return ret;
132 	}
133 
134 	if (pdata->dvfs_step_20mV)
135 		control |= TPS51632_DVFS_STEP_20;
136 
137 	if (pdata->max_voltage_uV) {
138 		unsigned int vmax;
139 		/**
140 		 * TPS51632 hw behavior: VMAX register can be write only
141 		 * once as it get locked after first write. The lock get
142 		 * reset only when device is power-reset.
143 		 * Write register only when lock bit is not enabled.
144 		 */
145 		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
146 		if (ret < 0) {
147 			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
148 			return ret;
149 		}
150 		if (!(vmax & TPS51632_VMAX_LOCK)) {
151 			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
152 			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
153 					vsel);
154 			if (ret < 0) {
155 				dev_err(tps->dev,
156 					"VMAX write failed, err %d\n", ret);
157 				return ret;
158 			}
159 		}
160 	}
161 
162 skip_pwm_config:
163 	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
164 	if (ret < 0)
165 		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
166 	return ret;
167 }
168 
169 static bool is_volatile_reg(struct device *dev, unsigned int reg)
170 {
171 	switch (reg) {
172 	case TPS51632_OFFSET_REG:
173 	case TPS51632_FAULT_REG:
174 	case TPS51632_IMON_REG:
175 		return true;
176 	default:
177 		return false;
178 	}
179 }
180 
181 static bool is_read_reg(struct device *dev, unsigned int reg)
182 {
183 	switch (reg) {
184 	case 0x08 ... 0x0F:
185 		return false;
186 	default:
187 		return true;
188 	}
189 }
190 
191 static bool is_write_reg(struct device *dev, unsigned int reg)
192 {
193 	switch (reg) {
194 	case TPS51632_VOLTAGE_SELECT_REG:
195 	case TPS51632_VOLTAGE_BASE_REG:
196 	case TPS51632_VMAX_REG:
197 	case TPS51632_DVFS_CONTROL_REG:
198 	case TPS51632_POWER_STATE_REG:
199 	case TPS51632_SLEW_REGS:
200 		return true;
201 	default:
202 		return false;
203 	}
204 }
205 
206 static const struct regmap_config tps51632_regmap_config = {
207 	.reg_bits		= 8,
208 	.val_bits		= 8,
209 	.writeable_reg		= is_write_reg,
210 	.readable_reg		= is_read_reg,
211 	.volatile_reg		= is_volatile_reg,
212 	.max_register		= TPS51632_MAX_REG - 1,
213 	.cache_type		= REGCACHE_RBTREE,
214 };
215 
216 #if defined(CONFIG_OF)
217 static const struct of_device_id tps51632_of_match[] = {
218 	{ .compatible = "ti,tps51632",},
219 	{},
220 };
221 MODULE_DEVICE_TABLE(of, tps51632_of_match);
222 
223 static struct tps51632_regulator_platform_data *
224 	of_get_tps51632_platform_data(struct device *dev)
225 {
226 	struct tps51632_regulator_platform_data *pdata;
227 	struct device_node *np = dev->of_node;
228 
229 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
230 	if (!pdata) {
231 		dev_err(dev, "Memory alloc failed for platform data\n");
232 		return NULL;
233 	}
234 
235 	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node);
236 	if (!pdata->reg_init_data) {
237 		dev_err(dev, "Not able to get OF regulator init data\n");
238 		return NULL;
239 	}
240 
241 	pdata->enable_pwm_dvfs =
242 			of_property_read_bool(np, "ti,enable-pwm-dvfs");
243 	pdata->dvfs_step_20mV = of_property_read_bool(np, "ti,dvfs-step-20mV");
244 
245 	pdata->base_voltage_uV = pdata->reg_init_data->constraints.min_uV ? :
246 					TPS51632_MIN_VOLATGE;
247 	pdata->max_voltage_uV = pdata->reg_init_data->constraints.max_uV ? :
248 					TPS51632_MAX_VOLATGE;
249 	return pdata;
250 }
251 #else
252 static struct tps51632_regulator_platform_data *
253 	of_get_tps51632_platform_data(struct device *dev)
254 {
255 	return NULL;
256 }
257 #endif
258 
259 static int tps51632_probe(struct i2c_client *client,
260 				const struct i2c_device_id *id)
261 {
262 	struct tps51632_regulator_platform_data *pdata;
263 	struct regulator_dev *rdev;
264 	struct tps51632_chip *tps;
265 	int ret;
266 	struct regulator_config config = { };
267 
268 	if (client->dev.of_node) {
269 		const struct of_device_id *match;
270 		match = of_match_device(of_match_ptr(tps51632_of_match),
271 				&client->dev);
272 		if (!match) {
273 			dev_err(&client->dev, "Error: No device match found\n");
274 			return -ENODEV;
275 		}
276 	}
277 
278 	pdata = dev_get_platdata(&client->dev);
279 	if (!pdata && client->dev.of_node)
280 		pdata = of_get_tps51632_platform_data(&client->dev);
281 	if (!pdata) {
282 		dev_err(&client->dev, "No Platform data\n");
283 		return -EINVAL;
284 	}
285 
286 	if (pdata->enable_pwm_dvfs) {
287 		if ((pdata->base_voltage_uV < TPS51632_MIN_VOLATGE) ||
288 		    (pdata->base_voltage_uV > TPS51632_MAX_VOLATGE)) {
289 			dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
290 			return -EINVAL;
291 		}
292 
293 		if ((pdata->max_voltage_uV) &&
294 		    ((pdata->max_voltage_uV < TPS51632_MIN_VOLATGE) ||
295 		     (pdata->max_voltage_uV > TPS51632_MAX_VOLATGE))) {
296 			dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
297 			return -EINVAL;
298 		}
299 	}
300 
301 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
302 	if (!tps) {
303 		dev_err(&client->dev, "Memory allocation failed\n");
304 		return -ENOMEM;
305 	}
306 
307 	tps->dev = &client->dev;
308 	tps->desc.name = id->name;
309 	tps->desc.id = 0;
310 	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
311 	tps->desc.min_uV = TPS51632_MIN_VOLATGE;
312 	tps->desc.uV_step = TPS51632_VOLATGE_STEP_10mV;
313 	tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
314 	tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
315 	tps->desc.ops = &tps51632_dcdc_ops;
316 	tps->desc.type = REGULATOR_VOLTAGE;
317 	tps->desc.owner = THIS_MODULE;
318 
319 	if (pdata->enable_pwm_dvfs)
320 		tps->desc.vsel_reg = TPS51632_VOLTAGE_BASE_REG;
321 	else
322 		tps->desc.vsel_reg = TPS51632_VOLTAGE_SELECT_REG;
323 	tps->desc.vsel_mask = TPS51632_VOUT_MASK;
324 
325 	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
326 	if (IS_ERR(tps->regmap)) {
327 		ret = PTR_ERR(tps->regmap);
328 		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
329 		return ret;
330 	}
331 	i2c_set_clientdata(client, tps);
332 
333 	ret = tps51632_init_dcdc(tps, pdata);
334 	if (ret < 0) {
335 		dev_err(tps->dev, "Init failed, err = %d\n", ret);
336 		return ret;
337 	}
338 
339 	/* Register the regulators */
340 	config.dev = &client->dev;
341 	config.init_data = pdata->reg_init_data;
342 	config.driver_data = tps;
343 	config.regmap = tps->regmap;
344 	config.of_node = client->dev.of_node;
345 
346 	rdev = regulator_register(&tps->desc, &config);
347 	if (IS_ERR(rdev)) {
348 		dev_err(tps->dev, "regulator register failed\n");
349 		return PTR_ERR(rdev);
350 	}
351 
352 	tps->rdev = rdev;
353 	return 0;
354 }
355 
356 static int tps51632_remove(struct i2c_client *client)
357 {
358 	struct tps51632_chip *tps = i2c_get_clientdata(client);
359 
360 	regulator_unregister(tps->rdev);
361 	return 0;
362 }
363 
364 static const struct i2c_device_id tps51632_id[] = {
365 	{.name = "tps51632",},
366 	{},
367 };
368 
369 MODULE_DEVICE_TABLE(i2c, tps51632_id);
370 
371 static struct i2c_driver tps51632_i2c_driver = {
372 	.driver = {
373 		.name = "tps51632",
374 		.owner = THIS_MODULE,
375 		.of_match_table = of_match_ptr(tps51632_of_match),
376 	},
377 	.probe = tps51632_probe,
378 	.remove = tps51632_remove,
379 	.id_table = tps51632_id,
380 };
381 
382 static int __init tps51632_init(void)
383 {
384 	return i2c_add_driver(&tps51632_i2c_driver);
385 }
386 subsys_initcall(tps51632_init);
387 
388 static void __exit tps51632_cleanup(void)
389 {
390 	i2c_del_driver(&tps51632_i2c_driver);
391 }
392 module_exit(tps51632_cleanup);
393 
394 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
395 MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
396 MODULE_LICENSE("GPL v2");
397