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/platform_device.h>
32 #include <linux/regmap.h>
33 #include <linux/regulator/driver.h>
34 #include <linux/regulator/machine.h>
35 #include <linux/regulator/tps51632-regulator.h>
36 #include <linux/slab.h>
37 
38 /* Register definitions */
39 #define TPS51632_VOLTAGE_SELECT_REG		0x0
40 #define TPS51632_VOLTAGE_BASE_REG		0x1
41 #define TPS51632_OFFSET_REG			0x2
42 #define TPS51632_IMON_REG			0x3
43 #define TPS51632_VMAX_REG			0x4
44 #define TPS51632_DVFS_CONTROL_REG		0x5
45 #define TPS51632_POWER_STATE_REG		0x6
46 #define TPS51632_SLEW_REGS			0x7
47 #define TPS51632_FAULT_REG			0x14
48 
49 #define TPS51632_MAX_REG			0x15
50 
51 #define TPS51632_VOUT_MASK			0x7F
52 #define TPS51632_VOUT_OFFSET_MASK		0x1F
53 #define TPS51632_VMAX_MASK			0x7F
54 #define TPS51632_VMAX_LOCK			0x80
55 
56 /* TPS51632_DVFS_CONTROL_REG */
57 #define TPS51632_DVFS_PWMEN			0x1
58 #define TPS51632_DVFS_STEP_20			0x2
59 #define TPS51632_DVFS_VMAX_PG			0x4
60 #define TPS51632_DVFS_PWMRST			0x8
61 #define TPS51632_DVFS_OCA_EN			0x10
62 #define TPS51632_DVFS_FCCM			0x20
63 
64 /* TPS51632_POWER_STATE_REG */
65 #define TPS51632_POWER_STATE_MASK		0x03
66 #define TPS51632_POWER_STATE_MULTI_PHASE_CCM	0x0
67 #define TPS51632_POWER_STATE_SINGLE_PHASE_CCM	0x1
68 #define TPS51632_POWER_STATE_SINGLE_PHASE_DCM	0x2
69 
70 #define TPS51632_MIN_VOLATGE			500000
71 #define TPS51632_MAX_VOLATGE			1520000
72 #define TPS51632_VOLATGE_STEP_10mV		10000
73 #define TPS51632_VOLATGE_STEP_20mV		20000
74 #define TPS51632_MAX_VSEL			0x7F
75 #define TPS51632_MIN_VSEL			0x19
76 #define TPS51632_DEFAULT_RAMP_DELAY		6000
77 #define TPS51632_VOLT_VSEL(uV)					\
78 		(DIV_ROUND_UP(uV - TPS51632_MIN_VOLATGE,	\
79 			TPS51632_VOLATGE_STEP_10mV) +		\
80 			TPS51632_MIN_VSEL)
81 
82 /* TPS51632 chip information */
83 struct tps51632_chip {
84 	struct device *dev;
85 	struct regulator_desc desc;
86 	struct regulator_dev *rdev;
87 	struct regmap *regmap;
88 	bool enable_pwm_dvfs;
89 };
90 
91 static int tps51632_dcdc_get_voltage_sel(struct regulator_dev *rdev)
92 {
93 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
94 	unsigned int data;
95 	int ret;
96 	unsigned int reg = TPS51632_VOLTAGE_SELECT_REG;
97 	int vsel;
98 
99 	if (tps->enable_pwm_dvfs)
100 		reg = TPS51632_VOLTAGE_BASE_REG;
101 
102 	ret = regmap_read(tps->regmap, reg, &data);
103 	if (ret < 0) {
104 		dev_err(tps->dev, "reg read failed, err %d\n", ret);
105 		return ret;
106 	}
107 
108 	vsel = data & TPS51632_VOUT_MASK;
109 	return vsel;
110 }
111 
112 static int tps51632_dcdc_set_voltage_sel(struct regulator_dev *rdev,
113 		unsigned selector)
114 {
115 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
116 	int ret;
117 	unsigned int reg = TPS51632_VOLTAGE_SELECT_REG;
118 
119 	if (tps->enable_pwm_dvfs)
120 		reg = TPS51632_VOLTAGE_BASE_REG;
121 
122 	if (selector > TPS51632_MAX_VSEL)
123 		return -EINVAL;
124 
125 	ret = regmap_write(tps->regmap, reg, selector);
126 	if (ret < 0)
127 		dev_err(tps->dev, "reg write failed, err %d\n", ret);
128 	return ret;
129 }
130 
131 static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
132 		int ramp_delay)
133 {
134 	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
135 	int bit = ramp_delay/6000;
136 	int ret;
137 
138 	if (bit)
139 		bit--;
140 	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
141 	if (ret < 0)
142 		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
143 	return ret;
144 }
145 
146 static struct regulator_ops tps51632_dcdc_ops = {
147 	.get_voltage_sel	= tps51632_dcdc_get_voltage_sel,
148 	.set_voltage_sel	= tps51632_dcdc_set_voltage_sel,
149 	.list_voltage		= regulator_list_voltage_linear,
150 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
151 	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
152 };
153 
154 static int tps51632_init_dcdc(struct tps51632_chip *tps,
155 		struct tps51632_regulator_platform_data *pdata)
156 {
157 	int ret;
158 	uint8_t	control = 0;
159 	int vsel;
160 
161 	if (!pdata->enable_pwm_dvfs)
162 		goto skip_pwm_config;
163 
164 	control |= TPS51632_DVFS_PWMEN;
165 	tps->enable_pwm_dvfs = pdata->enable_pwm_dvfs;
166 	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
167 	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
168 	if (ret < 0) {
169 		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
170 		return ret;
171 	}
172 
173 	if (pdata->dvfs_step_20mV)
174 		control |= TPS51632_DVFS_STEP_20;
175 
176 	if (pdata->max_voltage_uV) {
177 		unsigned int vmax;
178 		/**
179 		 * TPS51632 hw behavior: VMAX register can be write only
180 		 * once as it get locked after first write. The lock get
181 		 * reset only when device is power-reset.
182 		 * Write register only when lock bit is not enabled.
183 		 */
184 		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
185 		if (ret < 0) {
186 			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
187 			return ret;
188 		}
189 		if (!(vmax & TPS51632_VMAX_LOCK)) {
190 			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
191 			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
192 					vsel);
193 			if (ret < 0) {
194 				dev_err(tps->dev,
195 					"VMAX write failed, err %d\n", ret);
196 				return ret;
197 			}
198 		}
199 	}
200 
201 skip_pwm_config:
202 	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
203 	if (ret < 0)
204 		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
205 	return ret;
206 }
207 
208 static bool rd_wr_reg(struct device *dev, unsigned int reg)
209 {
210 	if ((reg >= 0x8) && (reg <= 0x10))
211 		return false;
212 	return true;
213 }
214 
215 static const struct regmap_config tps51632_regmap_config = {
216 	.reg_bits		= 8,
217 	.val_bits		= 8,
218 	.writeable_reg		= rd_wr_reg,
219 	.readable_reg		= rd_wr_reg,
220 	.max_register		= TPS51632_MAX_REG - 1,
221 	.cache_type		= REGCACHE_RBTREE,
222 };
223 
224 static int tps51632_probe(struct i2c_client *client,
225 				const struct i2c_device_id *id)
226 {
227 	struct tps51632_regulator_platform_data *pdata;
228 	struct regulator_dev *rdev;
229 	struct tps51632_chip *tps;
230 	int ret;
231 	struct regulator_config config = { };
232 
233 	pdata = client->dev.platform_data;
234 	if (!pdata) {
235 		dev_err(&client->dev, "No Platform data\n");
236 		return -EINVAL;
237 	}
238 
239 	if (pdata->enable_pwm_dvfs) {
240 		if ((pdata->base_voltage_uV < TPS51632_MIN_VOLATGE) ||
241 		    (pdata->base_voltage_uV > TPS51632_MAX_VOLATGE)) {
242 			dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
243 			return -EINVAL;
244 		}
245 
246 		if ((pdata->max_voltage_uV) &&
247 		    ((pdata->max_voltage_uV < TPS51632_MIN_VOLATGE) ||
248 		     (pdata->max_voltage_uV > TPS51632_MAX_VOLATGE))) {
249 			dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
250 			return -EINVAL;
251 		}
252 	}
253 
254 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
255 	if (!tps) {
256 		dev_err(&client->dev, "Memory allocation failed\n");
257 		return -ENOMEM;
258 	}
259 
260 	tps->dev = &client->dev;
261 	tps->desc.name = id->name;
262 	tps->desc.id = 0;
263 	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
264 	tps->desc.min_uV = TPS51632_MIN_VOLATGE;
265 	tps->desc.uV_step = TPS51632_VOLATGE_STEP_10mV;
266 	tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
267 	tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
268 	tps->desc.ops = &tps51632_dcdc_ops;
269 	tps->desc.type = REGULATOR_VOLTAGE;
270 	tps->desc.owner = THIS_MODULE;
271 
272 	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
273 	if (IS_ERR(tps->regmap)) {
274 		ret = PTR_ERR(tps->regmap);
275 		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
276 		return ret;
277 	}
278 	i2c_set_clientdata(client, tps);
279 
280 	ret = tps51632_init_dcdc(tps, pdata);
281 	if (ret < 0) {
282 		dev_err(tps->dev, "Init failed, err = %d\n", ret);
283 		return ret;
284 	}
285 
286 	/* Register the regulators */
287 	config.dev = &client->dev;
288 	config.init_data = pdata->reg_init_data;
289 	config.driver_data = tps;
290 	config.regmap = tps->regmap;
291 	config.of_node = client->dev.of_node;
292 
293 	rdev = regulator_register(&tps->desc, &config);
294 	if (IS_ERR(rdev)) {
295 		dev_err(tps->dev, "regulator register failed\n");
296 		return PTR_ERR(rdev);
297 	}
298 
299 	tps->rdev = rdev;
300 	return 0;
301 }
302 
303 static int tps51632_remove(struct i2c_client *client)
304 {
305 	struct tps51632_chip *tps = i2c_get_clientdata(client);
306 
307 	regulator_unregister(tps->rdev);
308 	return 0;
309 }
310 
311 static const struct i2c_device_id tps51632_id[] = {
312 	{.name = "tps51632",},
313 	{},
314 };
315 
316 MODULE_DEVICE_TABLE(i2c, tps51632_id);
317 
318 static struct i2c_driver tps51632_i2c_driver = {
319 	.driver = {
320 		.name = "tps51632",
321 		.owner = THIS_MODULE,
322 	},
323 	.probe = tps51632_probe,
324 	.remove = tps51632_remove,
325 	.id_table = tps51632_id,
326 };
327 
328 static int __init tps51632_init(void)
329 {
330 	return i2c_add_driver(&tps51632_i2c_driver);
331 }
332 subsys_initcall(tps51632_init);
333 
334 static void __exit tps51632_cleanup(void)
335 {
336 	i2c_del_driver(&tps51632_i2c_driver);
337 }
338 module_exit(tps51632_cleanup);
339 
340 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
341 MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
342 MODULE_LICENSE("GPL v2");
343