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_VOLTAGE			500000
74 #define TPS51632_MAX_VOLTAGE			1520000
75 #define TPS51632_VOLTAGE_STEP_10mV		10000
76 #define TPS51632_VOLTAGE_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_VOLTAGE,	\
82 			TPS51632_VOLTAGE_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;
98 	int ret;
99 
100 	if (ramp_delay == 0)
101 		bit = 0;
102 	else
103 		bit = DIV_ROUND_UP(ramp_delay, 6000) - 1;
104 
105 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
106 	if (ret < 0)
107 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
108 	return ret;
109 }
110 
111 static struct regulator_ops tps51632_dcdc_ops = {
112 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
113 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
114 	.list_voltage		= regulator_list_voltage_linear,
115 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
116 	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
117 };
118 
119 static int tps51632_init_dcdc(struct tps51632_chip *tps,
120 		struct tps51632_regulator_platform_data *pdata)
121 {
122 	int ret;
123 	uint8_t	control = 0;
124 	int vsel;
125 
126 	if (!pdata->enable_pwm_dvfs)
127 		goto skip_pwm_config;
128 
129 	control |= TPS51632_DVFS_PWMEN;
130 	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
131 	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
132 	if (ret < 0) {
133 		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
134 		return ret;
135 	}
136 
137 	if (pdata->dvfs_step_20mV)
138 		control |= TPS51632_DVFS_STEP_20;
139 
140 	if (pdata->max_voltage_uV) {
141 		unsigned int vmax;
142 		/**
143 		 * TPS51632 hw behavior: VMAX register can be write only
144 		 * once as it get locked after first write. The lock get
145 		 * reset only when device is power-reset.
146 		 * Write register only when lock bit is not enabled.
147 		 */
148 		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
149 		if (ret < 0) {
150 			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
151 			return ret;
152 		}
153 		if (!(vmax & TPS51632_VMAX_LOCK)) {
154 			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
155 			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
156 					vsel);
157 			if (ret < 0) {
158 				dev_err(tps->dev,
159 					"VMAX write failed, err %d\n", ret);
160 				return ret;
161 			}
162 		}
163 	}
164 
165 skip_pwm_config:
166 	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
167 	if (ret < 0)
168 		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
169 	return ret;
170 }
171 
172 static bool is_volatile_reg(struct device *dev, unsigned int reg)
173 {
174 	switch (reg) {
175 	case TPS51632_OFFSET_REG:
176 	case TPS51632_FAULT_REG:
177 	case TPS51632_IMON_REG:
178 		return true;
179 	default:
180 		return false;
181 	}
182 }
183 
184 static bool is_read_reg(struct device *dev, unsigned int reg)
185 {
186 	switch (reg) {
187 	case 0x08 ... 0x0F:
188 		return false;
189 	default:
190 		return true;
191 	}
192 }
193 
194 static bool is_write_reg(struct device *dev, unsigned int reg)
195 {
196 	switch (reg) {
197 	case TPS51632_VOLTAGE_SELECT_REG:
198 	case TPS51632_VOLTAGE_BASE_REG:
199 	case TPS51632_VMAX_REG:
200 	case TPS51632_DVFS_CONTROL_REG:
201 	case TPS51632_POWER_STATE_REG:
202 	case TPS51632_SLEW_REGS:
203 		return true;
204 	default:
205 		return false;
206 	}
207 }
208 
209 static const struct regmap_config tps51632_regmap_config = {
210 	.reg_bits		= 8,
211 	.val_bits		= 8,
212 	.writeable_reg		= is_write_reg,
213 	.readable_reg		= is_read_reg,
214 	.volatile_reg		= is_volatile_reg,
215 	.max_register		= TPS51632_MAX_REG - 1,
216 	.cache_type		= REGCACHE_RBTREE,
217 };
218 
219 #if defined(CONFIG_OF)
220 static const struct of_device_id tps51632_of_match[] = {
221 	{ .compatible = "ti,tps51632",},
222 	{},
223 };
224 MODULE_DEVICE_TABLE(of, tps51632_of_match);
225 
226 static struct tps51632_regulator_platform_data *
227 	of_get_tps51632_platform_data(struct device *dev,
228 				      const struct regulator_desc *desc)
229 {
230 	struct tps51632_regulator_platform_data *pdata;
231 	struct device_node *np = dev->of_node;
232 
233 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
234 	if (!pdata)
235 		return NULL;
236 
237 	pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node,
238 							  desc);
239 	if (!pdata->reg_init_data) {
240 		dev_err(dev, "Not able to get OF regulator init data\n");
241 		return NULL;
242 	}
243 
244 	pdata->enable_pwm_dvfs =
245 			of_property_read_bool(np, "ti,enable-pwm-dvfs");
246 	pdata->dvfs_step_20mV = of_property_read_bool(np, "ti,dvfs-step-20mV");
247 
248 	pdata->base_voltage_uV = pdata->reg_init_data->constraints.min_uV ? :
249 					TPS51632_MIN_VOLTAGE;
250 	pdata->max_voltage_uV = pdata->reg_init_data->constraints.max_uV ? :
251 					TPS51632_MAX_VOLTAGE;
252 	return pdata;
253 }
254 #else
255 static struct tps51632_regulator_platform_data *
256 	of_get_tps51632_platform_data(struct device *dev,
257 				      const struct regulator_desc *desc)
258 {
259 	return NULL;
260 }
261 #endif
262 
263 static int tps51632_probe(struct i2c_client *client,
264 				const struct i2c_device_id *id)
265 {
266 	struct tps51632_regulator_platform_data *pdata;
267 	struct regulator_dev *rdev;
268 	struct tps51632_chip *tps;
269 	int ret;
270 	struct regulator_config config = { };
271 
272 	if (client->dev.of_node) {
273 		const struct of_device_id *match;
274 		match = of_match_device(of_match_ptr(tps51632_of_match),
275 				&client->dev);
276 		if (!match) {
277 			dev_err(&client->dev, "Error: No device match found\n");
278 			return -ENODEV;
279 		}
280 	}
281 
282 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
283 	if (!tps)
284 		return -ENOMEM;
285 
286 	tps->dev = &client->dev;
287 	tps->desc.name = client->name;
288 	tps->desc.id = 0;
289 	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
290 	tps->desc.min_uV = TPS51632_MIN_VOLTAGE;
291 	tps->desc.uV_step = TPS51632_VOLTAGE_STEP_10mV;
292 	tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
293 	tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
294 	tps->desc.ops = &tps51632_dcdc_ops;
295 	tps->desc.type = REGULATOR_VOLTAGE;
296 	tps->desc.owner = THIS_MODULE;
297 
298 	pdata = dev_get_platdata(&client->dev);
299 	if (!pdata && client->dev.of_node)
300 		pdata = of_get_tps51632_platform_data(&client->dev, &tps->desc);
301 	if (!pdata) {
302 		dev_err(&client->dev, "No Platform data\n");
303 		return -EINVAL;
304 	}
305 
306 	if (pdata->enable_pwm_dvfs) {
307 		if ((pdata->base_voltage_uV < TPS51632_MIN_VOLTAGE) ||
308 		    (pdata->base_voltage_uV > TPS51632_MAX_VOLTAGE)) {
309 			dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
310 			return -EINVAL;
311 		}
312 
313 		if ((pdata->max_voltage_uV) &&
314 		    ((pdata->max_voltage_uV < TPS51632_MIN_VOLTAGE) ||
315 		     (pdata->max_voltage_uV > TPS51632_MAX_VOLTAGE))) {
316 			dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
317 			return -EINVAL;
318 		}
319 	}
320 
321 	if (pdata->enable_pwm_dvfs)
322 		tps->desc.vsel_reg = TPS51632_VOLTAGE_BASE_REG;
323 	else
324 		tps->desc.vsel_reg = TPS51632_VOLTAGE_SELECT_REG;
325 	tps->desc.vsel_mask = TPS51632_VOUT_MASK;
326 
327 	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
328 	if (IS_ERR(tps->regmap)) {
329 		ret = PTR_ERR(tps->regmap);
330 		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
331 		return ret;
332 	}
333 	i2c_set_clientdata(client, tps);
334 
335 	ret = tps51632_init_dcdc(tps, pdata);
336 	if (ret < 0) {
337 		dev_err(tps->dev, "Init failed, err = %d\n", ret);
338 		return ret;
339 	}
340 
341 	/* Register the regulators */
342 	config.dev = &client->dev;
343 	config.init_data = pdata->reg_init_data;
344 	config.driver_data = tps;
345 	config.regmap = tps->regmap;
346 	config.of_node = client->dev.of_node;
347 
348 	rdev = devm_regulator_register(&client->dev, &tps->desc, &config);
349 	if (IS_ERR(rdev)) {
350 		dev_err(tps->dev, "regulator register failed\n");
351 		return PTR_ERR(rdev);
352 	}
353 
354 	tps->rdev = rdev;
355 	return 0;
356 }
357 
358 static const struct i2c_device_id tps51632_id[] = {
359 	{.name = "tps51632",},
360 	{},
361 };
362 
363 MODULE_DEVICE_TABLE(i2c, tps51632_id);
364 
365 static struct i2c_driver tps51632_i2c_driver = {
366 	.driver = {
367 		.name = "tps51632",
368 		.of_match_table = of_match_ptr(tps51632_of_match),
369 	},
370 	.probe = tps51632_probe,
371 	.id_table = tps51632_id,
372 };
373 
374 static int __init tps51632_init(void)
375 {
376 	return i2c_add_driver(&tps51632_i2c_driver);
377 }
378 subsys_initcall(tps51632_init);
379 
380 static void __exit tps51632_cleanup(void)
381 {
382 	i2c_del_driver(&tps51632_i2c_driver);
383 }
384 module_exit(tps51632_cleanup);
385 
386 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
387 MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
388 MODULE_LICENSE("GPL v2");
389