1 /*
2  * da9210-regulator.c - Regulator device driver for DA9210
3  * Copyright (C) 2013  Dialog Semiconductor Ltd.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Library General Public License for more details.
14  *
15  * You should have received a copy of the GNU Library General Public
16  * License along with this library; if not, write to the
17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18  * Boston, MA  02110-1301, USA.
19  */
20 
21 #include <linux/err.h>
22 #include <linux/i2c.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/slab.h>
28 #include <linux/regulator/driver.h>
29 #include <linux/regulator/machine.h>
30 #include <linux/regulator/of_regulator.h>
31 #include <linux/regmap.h>
32 
33 #include "da9210-regulator.h"
34 
35 struct da9210 {
36 	struct regulator_dev *rdev;
37 	struct regmap *regmap;
38 };
39 
40 static const struct regmap_config da9210_regmap_config = {
41 	.reg_bits = 8,
42 	.val_bits = 8,
43 };
44 
45 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
46 				    int max_uA);
47 static int da9210_get_current_limit(struct regulator_dev *rdev);
48 
49 static const struct regulator_ops da9210_buck_ops = {
50 	.enable = regulator_enable_regmap,
51 	.disable = regulator_disable_regmap,
52 	.is_enabled = regulator_is_enabled_regmap,
53 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
54 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
55 	.list_voltage = regulator_list_voltage_linear,
56 	.set_current_limit = da9210_set_current_limit,
57 	.get_current_limit = da9210_get_current_limit,
58 };
59 
60 /* Default limits measured in millivolts and milliamps */
61 #define DA9210_MIN_MV		300
62 #define DA9210_MAX_MV		1570
63 #define DA9210_STEP_MV		10
64 
65 /* Current limits for buck (uA) indices corresponds with register values */
66 static const int da9210_buck_limits[] = {
67 	1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
68 	3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
69 };
70 
71 static const struct regulator_desc da9210_reg = {
72 	.name = "DA9210",
73 	.id = 0,
74 	.ops = &da9210_buck_ops,
75 	.type = REGULATOR_VOLTAGE,
76 	.n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
77 	.min_uV = (DA9210_MIN_MV * 1000),
78 	.uV_step = (DA9210_STEP_MV * 1000),
79 	.vsel_reg = DA9210_REG_VBUCK_A,
80 	.vsel_mask = DA9210_VBUCK_MASK,
81 	.enable_reg = DA9210_REG_BUCK_CONT,
82 	.enable_mask = DA9210_BUCK_EN,
83 	.owner = THIS_MODULE,
84 };
85 
86 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
87 				    int max_uA)
88 {
89 	struct da9210 *chip = rdev_get_drvdata(rdev);
90 	unsigned int sel;
91 	int i;
92 
93 	/* search for closest to maximum */
94 	for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
95 		if (min_uA <= da9210_buck_limits[i] &&
96 		    max_uA >= da9210_buck_limits[i]) {
97 			sel = i;
98 			sel = sel << DA9210_BUCK_ILIM_SHIFT;
99 			return regmap_update_bits(chip->regmap,
100 						  DA9210_REG_BUCK_ILIM,
101 						  DA9210_BUCK_ILIM_MASK, sel);
102 		}
103 	}
104 
105 	return -EINVAL;
106 }
107 
108 static int da9210_get_current_limit(struct regulator_dev *rdev)
109 {
110 	struct da9210 *chip = rdev_get_drvdata(rdev);
111 	unsigned int data;
112 	unsigned int sel;
113 	int ret;
114 
115 	ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
116 	if (ret < 0)
117 		return ret;
118 
119 	/* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
120 	sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
121 
122 	return da9210_buck_limits[sel];
123 }
124 
125 static irqreturn_t da9210_irq_handler(int irq, void *data)
126 {
127 	struct da9210 *chip = data;
128 	unsigned int val, handled = 0;
129 	int error, ret = IRQ_NONE;
130 
131 	error = regmap_read(chip->regmap, DA9210_REG_EVENT_B, &val);
132 	if (error < 0)
133 		goto error_i2c;
134 
135 	if (val & DA9210_E_OVCURR) {
136 		regulator_notifier_call_chain(chip->rdev,
137 					      REGULATOR_EVENT_OVER_CURRENT,
138 					      NULL);
139 		handled |= DA9210_E_OVCURR;
140 	}
141 	if (val & DA9210_E_NPWRGOOD) {
142 		regulator_notifier_call_chain(chip->rdev,
143 					      REGULATOR_EVENT_UNDER_VOLTAGE,
144 					      NULL);
145 		handled |= DA9210_E_NPWRGOOD;
146 	}
147 	if (val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT)) {
148 		regulator_notifier_call_chain(chip->rdev,
149 					      REGULATOR_EVENT_OVER_TEMP, NULL);
150 		handled |= val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT);
151 	}
152 	if (val & DA9210_E_VMAX) {
153 		regulator_notifier_call_chain(chip->rdev,
154 					      REGULATOR_EVENT_REGULATION_OUT,
155 					      NULL);
156 		handled |= DA9210_E_VMAX;
157 	}
158 	if (handled) {
159 		/* Clear handled events */
160 		error = regmap_write(chip->regmap, DA9210_REG_EVENT_B, handled);
161 		if (error < 0)
162 			goto error_i2c;
163 
164 		ret = IRQ_HANDLED;
165 	}
166 
167 	return ret;
168 
169 error_i2c:
170 	dev_err(regmap_get_device(chip->regmap), "I2C error : %d\n", error);
171 	return ret;
172 }
173 
174 /*
175  * I2C driver interface functions
176  */
177 static int da9210_i2c_probe(struct i2c_client *i2c,
178 			    const struct i2c_device_id *id)
179 {
180 	struct da9210 *chip;
181 	struct device *dev = &i2c->dev;
182 	struct da9210_pdata *pdata = dev_get_platdata(dev);
183 	struct regulator_dev *rdev = NULL;
184 	struct regulator_config config = { };
185 	int error;
186 
187 	chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
188 	if (!chip)
189 		return -ENOMEM;
190 
191 	chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
192 	if (IS_ERR(chip->regmap)) {
193 		error = PTR_ERR(chip->regmap);
194 		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
195 			error);
196 		return error;
197 	}
198 
199 	config.dev = &i2c->dev;
200 	config.init_data = pdata ? &pdata->da9210_constraints :
201 		of_get_regulator_init_data(dev, dev->of_node, &da9210_reg);
202 	config.driver_data = chip;
203 	config.regmap = chip->regmap;
204 	config.of_node = dev->of_node;
205 
206 	/* Mask all interrupt sources to deassert interrupt line */
207 	error = regmap_write(chip->regmap, DA9210_REG_MASK_A, ~0);
208 	if (!error)
209 		error = regmap_write(chip->regmap, DA9210_REG_MASK_B, ~0);
210 	if (error) {
211 		dev_err(&i2c->dev, "Failed to write to mask reg: %d\n", error);
212 		return error;
213 	}
214 
215 	rdev = devm_regulator_register(&i2c->dev, &da9210_reg, &config);
216 	if (IS_ERR(rdev)) {
217 		dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
218 		return PTR_ERR(rdev);
219 	}
220 
221 	chip->rdev = rdev;
222 	if (i2c->irq) {
223 		error = devm_request_threaded_irq(&i2c->dev, i2c->irq, NULL,
224 						  da9210_irq_handler,
225 						  IRQF_TRIGGER_LOW |
226 						  IRQF_ONESHOT | IRQF_SHARED,
227 						  "da9210", chip);
228 		if (error) {
229 			dev_err(&i2c->dev, "Failed to request IRQ%u: %d\n",
230 				i2c->irq, error);
231 			return error;
232 		}
233 
234 		error = regmap_update_bits(chip->regmap, DA9210_REG_MASK_B,
235 					 DA9210_M_OVCURR | DA9210_M_NPWRGOOD |
236 					 DA9210_M_TEMP_WARN |
237 					 DA9210_M_TEMP_CRIT | DA9210_M_VMAX, 0);
238 		if (error < 0) {
239 			dev_err(&i2c->dev, "Failed to update mask reg: %d\n",
240 				error);
241 			return error;
242 		}
243 	} else {
244 		dev_warn(&i2c->dev, "No IRQ configured\n");
245 	}
246 
247 	i2c_set_clientdata(i2c, chip);
248 
249 	return 0;
250 }
251 
252 static const struct i2c_device_id da9210_i2c_id[] = {
253 	{"da9210", 0},
254 	{},
255 };
256 
257 MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
258 
259 static struct i2c_driver da9210_regulator_driver = {
260 	.driver = {
261 		.name = "da9210",
262 	},
263 	.probe = da9210_i2c_probe,
264 	.id_table = da9210_i2c_id,
265 };
266 
267 module_i2c_driver(da9210_regulator_driver);
268 
269 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
270 MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
271 MODULE_LICENSE("GPL v2");
272