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
35struct da9210 {
36	struct regulator_dev *rdev;
37	struct regmap *regmap;
38};
39
40static const struct regmap_config da9210_regmap_config = {
41	.reg_bits = 8,
42	.val_bits = 8,
43};
44
45static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
46				    int max_uA);
47static int da9210_get_current_limit(struct regulator_dev *rdev);
48
49static 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 */
66static 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
71static 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
86static 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
108static 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
125static 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
169error_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 */
177static 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
252static const struct i2c_device_id da9210_i2c_id[] = {
253	{"da9210", 0},
254	{},
255};
256
257MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
258
259static 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
267module_i2c_driver(da9210_regulator_driver);
268
269MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
270MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
271MODULE_LICENSE("GPL v2");
272