1 /*
2  * Regulators driver for Maxim max8925
3  *
4  * Copyright (C) 2009 Marvell International Ltd.
5  *      Haojian Zhuang <haojian.zhuang@marvell.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/err.h>
15 #include <linux/i2c.h>
16 #include <linux/platform_device.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/regulator/machine.h>
19 #include <linux/mfd/max8925.h>
20 
21 #define SD1_DVM_VMIN		850000
22 #define SD1_DVM_VMAX		1000000
23 #define SD1_DVM_STEP		50000
24 #define SD1_DVM_SHIFT		5		/* SDCTL1 bit5 */
25 #define SD1_DVM_EN		6		/* SDV1 bit 6 */
26 
27 /* bit definitions in LDO control registers */
28 #define LDO_SEQ_I2C		0x7		/* Power U/D by i2c */
29 #define LDO_SEQ_MASK		0x7		/* Power U/D sequence mask */
30 #define LDO_SEQ_SHIFT		2		/* Power U/D sequence offset */
31 #define LDO_I2C_EN		0x1		/* Enable by i2c */
32 #define LDO_I2C_EN_MASK		0x1		/* Enable mask by i2c */
33 #define LDO_I2C_EN_SHIFT	0		/* Enable offset by i2c */
34 
35 struct max8925_regulator_info {
36 	struct regulator_desc	desc;
37 	struct regulator_dev	*regulator;
38 	struct i2c_client	*i2c;
39 	struct max8925_chip	*chip;
40 
41 	int	min_uV;
42 	int	max_uV;
43 	int	step_uV;
44 	int	vol_reg;
45 	int	vol_shift;
46 	int	vol_nbits;
47 	int	enable_reg;
48 };
49 
50 static inline int check_range(struct max8925_regulator_info *info,
51 			      int min_uV, int max_uV)
52 {
53 	if (min_uV < info->min_uV || min_uV > info->max_uV)
54 		return -EINVAL;
55 
56 	return 0;
57 }
58 
59 static int max8925_list_voltage(struct regulator_dev *rdev, unsigned index)
60 {
61 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
62 	return info->min_uV + index * info->step_uV;
63 }
64 
65 static int max8925_set_voltage(struct regulator_dev *rdev,
66 			       int min_uV, int max_uV, unsigned int *selector)
67 {
68 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
69 	unsigned char data, mask;
70 
71 	if (check_range(info, min_uV, max_uV)) {
72 		dev_err(info->chip->dev, "invalid voltage range (%d, %d) uV\n",
73 			min_uV, max_uV);
74 		return -EINVAL;
75 	}
76 	data = DIV_ROUND_UP(min_uV - info->min_uV, info->step_uV);
77 	*selector = data;
78 	data <<= info->vol_shift;
79 	mask = ((1 << info->vol_nbits) - 1) << info->vol_shift;
80 
81 	return max8925_set_bits(info->i2c, info->vol_reg, mask, data);
82 }
83 
84 static int max8925_get_voltage(struct regulator_dev *rdev)
85 {
86 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
87 	unsigned char data, mask;
88 	int ret;
89 
90 	ret = max8925_reg_read(info->i2c, info->vol_reg);
91 	if (ret < 0)
92 		return ret;
93 	mask = ((1 << info->vol_nbits) - 1) << info->vol_shift;
94 	data = (ret & mask) >> info->vol_shift;
95 
96 	return max8925_list_voltage(rdev, data);
97 }
98 
99 static int max8925_enable(struct regulator_dev *rdev)
100 {
101 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
102 
103 	return max8925_set_bits(info->i2c, info->enable_reg,
104 				LDO_SEQ_MASK << LDO_SEQ_SHIFT |
105 				LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
106 				LDO_SEQ_I2C << LDO_SEQ_SHIFT |
107 				LDO_I2C_EN << LDO_I2C_EN_SHIFT);
108 }
109 
110 static int max8925_disable(struct regulator_dev *rdev)
111 {
112 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
113 
114 	return max8925_set_bits(info->i2c, info->enable_reg,
115 				LDO_SEQ_MASK << LDO_SEQ_SHIFT |
116 				LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
117 				LDO_SEQ_I2C << LDO_SEQ_SHIFT);
118 }
119 
120 static int max8925_is_enabled(struct regulator_dev *rdev)
121 {
122 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
123 	int ldo_seq, ret;
124 
125 	ret = max8925_reg_read(info->i2c, info->enable_reg);
126 	if (ret < 0)
127 		return ret;
128 	ldo_seq = (ret >> LDO_SEQ_SHIFT) & LDO_SEQ_MASK;
129 	if (ldo_seq != LDO_SEQ_I2C)
130 		return 1;
131 	else
132 		return ret & (LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT);
133 }
134 
135 static int max8925_set_dvm_voltage(struct regulator_dev *rdev, int uV)
136 {
137 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
138 	unsigned char data, mask;
139 
140 	if (uV < SD1_DVM_VMIN || uV > SD1_DVM_VMAX)
141 		return -EINVAL;
142 
143 	data = DIV_ROUND_UP(uV - SD1_DVM_VMIN, SD1_DVM_STEP);
144 	data <<= SD1_DVM_SHIFT;
145 	mask = 3 << SD1_DVM_SHIFT;
146 
147 	return max8925_set_bits(info->i2c, info->enable_reg, mask, data);
148 }
149 
150 static int max8925_set_dvm_enable(struct regulator_dev *rdev)
151 {
152 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
153 
154 	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN,
155 				1 << SD1_DVM_EN);
156 }
157 
158 static int max8925_set_dvm_disable(struct regulator_dev *rdev)
159 {
160 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
161 
162 	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN, 0);
163 }
164 
165 static struct regulator_ops max8925_regulator_sdv_ops = {
166 	.set_voltage		= max8925_set_voltage,
167 	.get_voltage		= max8925_get_voltage,
168 	.enable			= max8925_enable,
169 	.disable		= max8925_disable,
170 	.is_enabled		= max8925_is_enabled,
171 	.set_suspend_voltage	= max8925_set_dvm_voltage,
172 	.set_suspend_enable	= max8925_set_dvm_enable,
173 	.set_suspend_disable	= max8925_set_dvm_disable,
174 };
175 
176 static struct regulator_ops max8925_regulator_ldo_ops = {
177 	.set_voltage		= max8925_set_voltage,
178 	.get_voltage		= max8925_get_voltage,
179 	.enable			= max8925_enable,
180 	.disable		= max8925_disable,
181 	.is_enabled		= max8925_is_enabled,
182 };
183 
184 #define MAX8925_SDV(_id, min, max, step)			\
185 {								\
186 	.desc	= {						\
187 		.name	= "SDV" #_id,				\
188 		.ops	= &max8925_regulator_sdv_ops,		\
189 		.type	= REGULATOR_VOLTAGE,			\
190 		.id	= MAX8925_ID_SD##_id,			\
191 		.owner	= THIS_MODULE,				\
192 	},							\
193 	.min_uV		= min * 1000,				\
194 	.max_uV		= max * 1000,				\
195 	.step_uV	= step * 1000,				\
196 	.vol_reg	= MAX8925_SDV##_id,			\
197 	.vol_shift	= 0,					\
198 	.vol_nbits	= 6,					\
199 	.enable_reg	= MAX8925_SDCTL##_id,			\
200 }
201 
202 #define MAX8925_LDO(_id, min, max, step)			\
203 {								\
204 	.desc	= {						\
205 		.name	= "LDO" #_id,				\
206 		.ops	= &max8925_regulator_ldo_ops,		\
207 		.type	= REGULATOR_VOLTAGE,			\
208 		.id	= MAX8925_ID_LDO##_id,			\
209 		.owner	= THIS_MODULE,				\
210 	},							\
211 	.min_uV		= min * 1000,				\
212 	.max_uV		= max * 1000,				\
213 	.step_uV	= step * 1000,				\
214 	.vol_reg	= MAX8925_LDOVOUT##_id,			\
215 	.vol_shift	= 0,					\
216 	.vol_nbits	= 6,					\
217 	.enable_reg	= MAX8925_LDOCTL##_id,			\
218 }
219 
220 static struct max8925_regulator_info max8925_regulator_info[] = {
221 	MAX8925_SDV(1, 637.5, 1425, 12.5),
222 	MAX8925_SDV(2,   650, 2225,   25),
223 	MAX8925_SDV(3,   750, 3900,   50),
224 
225 	MAX8925_LDO(1,  750, 3900, 50),
226 	MAX8925_LDO(2,  650, 2250, 25),
227 	MAX8925_LDO(3,  650, 2250, 25),
228 	MAX8925_LDO(4,  750, 3900, 50),
229 	MAX8925_LDO(5,  750, 3900, 50),
230 	MAX8925_LDO(6,  750, 3900, 50),
231 	MAX8925_LDO(7,  750, 3900, 50),
232 	MAX8925_LDO(8,  750, 3900, 50),
233 	MAX8925_LDO(9,  750, 3900, 50),
234 	MAX8925_LDO(10, 750, 3900, 50),
235 	MAX8925_LDO(11, 750, 3900, 50),
236 	MAX8925_LDO(12, 750, 3900, 50),
237 	MAX8925_LDO(13, 750, 3900, 50),
238 	MAX8925_LDO(14, 750, 3900, 50),
239 	MAX8925_LDO(15, 750, 3900, 50),
240 	MAX8925_LDO(16, 750, 3900, 50),
241 	MAX8925_LDO(17, 650, 2250, 25),
242 	MAX8925_LDO(18, 650, 2250, 25),
243 	MAX8925_LDO(19, 750, 3900, 50),
244 	MAX8925_LDO(20, 750, 3900, 50),
245 };
246 
247 static struct max8925_regulator_info * __devinit find_regulator_info(int id)
248 {
249 	struct max8925_regulator_info *ri;
250 	int i;
251 
252 	for (i = 0; i < ARRAY_SIZE(max8925_regulator_info); i++) {
253 		ri = &max8925_regulator_info[i];
254 		if (ri->desc.id == id)
255 			return ri;
256 	}
257 	return NULL;
258 }
259 
260 static int __devinit max8925_regulator_probe(struct platform_device *pdev)
261 {
262 	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
263 	struct max8925_platform_data *pdata = chip->dev->platform_data;
264 	struct max8925_regulator_info *ri;
265 	struct regulator_dev *rdev;
266 
267 	ri = find_regulator_info(pdev->id);
268 	if (ri == NULL) {
269 		dev_err(&pdev->dev, "invalid regulator ID specified\n");
270 		return -EINVAL;
271 	}
272 	ri->i2c = chip->i2c;
273 	ri->chip = chip;
274 
275 	rdev = regulator_register(&ri->desc, &pdev->dev,
276 				  pdata->regulator[pdev->id], ri, NULL);
277 	if (IS_ERR(rdev)) {
278 		dev_err(&pdev->dev, "failed to register regulator %s\n",
279 				ri->desc.name);
280 		return PTR_ERR(rdev);
281 	}
282 
283 	platform_set_drvdata(pdev, rdev);
284 	return 0;
285 }
286 
287 static int __devexit max8925_regulator_remove(struct platform_device *pdev)
288 {
289 	struct regulator_dev *rdev = platform_get_drvdata(pdev);
290 
291 	platform_set_drvdata(pdev, NULL);
292 	regulator_unregister(rdev);
293 
294 	return 0;
295 }
296 
297 static struct platform_driver max8925_regulator_driver = {
298 	.driver		= {
299 		.name	= "max8925-regulator",
300 		.owner	= THIS_MODULE,
301 	},
302 	.probe		= max8925_regulator_probe,
303 	.remove		= __devexit_p(max8925_regulator_remove),
304 };
305 
306 static int __init max8925_regulator_init(void)
307 {
308 	return platform_driver_register(&max8925_regulator_driver);
309 }
310 subsys_initcall(max8925_regulator_init);
311 
312 static void __exit max8925_regulator_exit(void)
313 {
314 	platform_driver_unregister(&max8925_regulator_driver);
315 }
316 module_exit(max8925_regulator_exit);
317 
318 MODULE_LICENSE("GPL");
319 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
320 MODULE_DESCRIPTION("Regulator Driver for Maxim 8925 PMIC");
321 MODULE_ALIAS("platform:max8925-regulator");
322 
323