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/init.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/platform_device.h>
16 #include <linux/regulator/driver.h>
17 #include <linux/regulator/machine.h>
18 #include <linux/mfd/max8925.h>
19 
20 #define SD1_DVM_VMIN		850000
21 #define SD1_DVM_VMAX		1000000
22 #define SD1_DVM_STEP		50000
23 #define SD1_DVM_SHIFT		5		/* SDCTL1 bit5 */
24 #define SD1_DVM_EN		6		/* SDV1 bit 6 */
25 
26 /* bit definitions in SD & LDO control registers */
27 #define OUT_ENABLE   		0x1f		/* Power U/D sequence as I2C */
28 #define OUT_DISABLE		0x1e		/* Power U/D sequence as I2C */
29 
30 struct max8925_regulator_info {
31 	struct regulator_desc	desc;
32 	struct regulator_dev	*regulator;
33 	struct i2c_client	*i2c;
34 	struct max8925_chip	*chip;
35 
36 	int	min_uV;
37 	int	max_uV;
38 	int	step_uV;
39 	int	vol_reg;
40 	int	vol_shift;
41 	int	vol_nbits;
42 	int	enable_bit;
43 	int	enable_reg;
44 };
45 
46 static inline int check_range(struct max8925_regulator_info *info,
47 			      int min_uV, int max_uV)
48 {
49 	if (min_uV < info->min_uV || min_uV > info->max_uV)
50 		return -EINVAL;
51 
52 	return 0;
53 }
54 
55 static int max8925_list_voltage(struct regulator_dev *rdev, unsigned index)
56 {
57 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
58 	return info->min_uV + index * info->step_uV;
59 }
60 
61 static int max8925_set_voltage(struct regulator_dev *rdev,
62 			       int min_uV, int max_uV, unsigned int *selector)
63 {
64 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
65 	unsigned char data, mask;
66 
67 	if (check_range(info, min_uV, max_uV)) {
68 		dev_err(info->chip->dev, "invalid voltage range (%d, %d) uV\n",
69 			min_uV, max_uV);
70 		return -EINVAL;
71 	}
72 	data = (min_uV - info->min_uV + info->step_uV - 1) / info->step_uV;
73 	*selector = data;
74 	data <<= info->vol_shift;
75 	mask = ((1 << info->vol_nbits) - 1) << info->vol_shift;
76 
77 	return max8925_set_bits(info->i2c, info->vol_reg, mask, data);
78 }
79 
80 static int max8925_get_voltage(struct regulator_dev *rdev)
81 {
82 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
83 	unsigned char data, mask;
84 	int ret;
85 
86 	ret = max8925_reg_read(info->i2c, info->vol_reg);
87 	if (ret < 0)
88 		return ret;
89 	mask = ((1 << info->vol_nbits) - 1) << info->vol_shift;
90 	data = (ret & mask) >> info->vol_shift;
91 
92 	return max8925_list_voltage(rdev, data);
93 }
94 
95 static int max8925_enable(struct regulator_dev *rdev)
96 {
97 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
98 
99 	return max8925_set_bits(info->i2c, info->enable_reg,
100 				OUT_ENABLE << info->enable_bit,
101 				OUT_ENABLE << info->enable_bit);
102 }
103 
104 static int max8925_disable(struct regulator_dev *rdev)
105 {
106 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
107 
108 	return max8925_set_bits(info->i2c, info->enable_reg,
109 				OUT_ENABLE << info->enable_bit,
110 				OUT_DISABLE << info->enable_bit);
111 }
112 
113 static int max8925_is_enabled(struct regulator_dev *rdev)
114 {
115 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
116 	int ret;
117 
118 	ret = max8925_reg_read(info->i2c, info->enable_reg);
119 	if (ret < 0)
120 		return ret;
121 
122 	return ret & (1 << info->enable_bit);
123 }
124 
125 static int max8925_set_dvm_voltage(struct regulator_dev *rdev, int uV)
126 {
127 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
128 	unsigned char data, mask;
129 
130 	if (uV < SD1_DVM_VMIN || uV > SD1_DVM_VMAX)
131 		return -EINVAL;
132 
133 	data = (uV - SD1_DVM_VMIN + SD1_DVM_STEP - 1) / SD1_DVM_STEP;
134 	data <<= SD1_DVM_SHIFT;
135 	mask = 3 << SD1_DVM_SHIFT;
136 
137 	return max8925_set_bits(info->i2c, info->enable_reg, mask, data);
138 }
139 
140 static int max8925_set_dvm_enable(struct regulator_dev *rdev)
141 {
142 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
143 
144 	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN,
145 				1 << SD1_DVM_EN);
146 }
147 
148 static int max8925_set_dvm_disable(struct regulator_dev *rdev)
149 {
150 	struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
151 
152 	return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN, 0);
153 }
154 
155 static struct regulator_ops max8925_regulator_sdv_ops = {
156 	.set_voltage		= max8925_set_voltage,
157 	.get_voltage		= max8925_get_voltage,
158 	.enable			= max8925_enable,
159 	.disable		= max8925_disable,
160 	.is_enabled		= max8925_is_enabled,
161 	.set_suspend_voltage	= max8925_set_dvm_voltage,
162 	.set_suspend_enable	= max8925_set_dvm_enable,
163 	.set_suspend_disable	= max8925_set_dvm_disable,
164 };
165 
166 static struct regulator_ops max8925_regulator_ldo_ops = {
167 	.set_voltage		= max8925_set_voltage,
168 	.get_voltage		= max8925_get_voltage,
169 	.enable			= max8925_enable,
170 	.disable		= max8925_disable,
171 	.is_enabled		= max8925_is_enabled,
172 };
173 
174 #define MAX8925_SDV(_id, min, max, step)			\
175 {								\
176 	.desc	= {						\
177 		.name	= "SDV" #_id,				\
178 		.ops	= &max8925_regulator_sdv_ops,		\
179 		.type	= REGULATOR_VOLTAGE,			\
180 		.id	= MAX8925_ID_SD##_id,			\
181 		.owner	= THIS_MODULE,				\
182 	},							\
183 	.min_uV		= min * 1000,				\
184 	.max_uV		= max * 1000,				\
185 	.step_uV	= step * 1000,				\
186 	.vol_reg	= MAX8925_SDV##_id,			\
187 	.vol_shift	= 0,					\
188 	.vol_nbits	= 6,					\
189 	.enable_reg	= MAX8925_SDCTL##_id,			\
190 	.enable_bit	= 0,					\
191 }
192 
193 #define MAX8925_LDO(_id, min, max, step)			\
194 {								\
195 	.desc	= {						\
196 		.name	= "LDO" #_id,				\
197 		.ops	= &max8925_regulator_ldo_ops,		\
198 		.type	= REGULATOR_VOLTAGE,			\
199 		.id	= MAX8925_ID_LDO##_id,			\
200 		.owner	= THIS_MODULE,				\
201 	},							\
202 	.min_uV		= min * 1000,				\
203 	.max_uV		= max * 1000,				\
204 	.step_uV	= step * 1000,				\
205 	.vol_reg	= MAX8925_LDOVOUT##_id,			\
206 	.vol_shift	= 0,					\
207 	.vol_nbits	= 6,					\
208 	.enable_reg	= MAX8925_LDOCTL##_id,			\
209 	.enable_bit	= 0,					\
210 }
211 
212 static struct max8925_regulator_info max8925_regulator_info[] = {
213 	MAX8925_SDV(1, 637.5, 1425, 12.5),
214 	MAX8925_SDV(2,   650, 2225,   25),
215 	MAX8925_SDV(3,   750, 3900,   50),
216 
217 	MAX8925_LDO(1,  750, 3900, 50),
218 	MAX8925_LDO(2,  650, 2250, 25),
219 	MAX8925_LDO(3,  650, 2250, 25),
220 	MAX8925_LDO(4,  750, 3900, 50),
221 	MAX8925_LDO(5,  750, 3900, 50),
222 	MAX8925_LDO(6,  750, 3900, 50),
223 	MAX8925_LDO(7,  750, 3900, 50),
224 	MAX8925_LDO(8,  750, 3900, 50),
225 	MAX8925_LDO(9,  750, 3900, 50),
226 	MAX8925_LDO(10, 750, 3900, 50),
227 	MAX8925_LDO(11, 750, 3900, 50),
228 	MAX8925_LDO(12, 750, 3900, 50),
229 	MAX8925_LDO(13, 750, 3900, 50),
230 	MAX8925_LDO(14, 750, 3900, 50),
231 	MAX8925_LDO(15, 750, 3900, 50),
232 	MAX8925_LDO(16, 750, 3900, 50),
233 	MAX8925_LDO(17, 650, 2250, 25),
234 	MAX8925_LDO(18, 650, 2250, 25),
235 	MAX8925_LDO(19, 750, 3900, 50),
236 	MAX8925_LDO(20, 750, 3900, 50),
237 };
238 
239 static struct max8925_regulator_info * __devinit find_regulator_info(int id)
240 {
241 	struct max8925_regulator_info *ri;
242 	int i;
243 
244 	for (i = 0; i < ARRAY_SIZE(max8925_regulator_info); i++) {
245 		ri = &max8925_regulator_info[i];
246 		if (ri->desc.id == id)
247 			return ri;
248 	}
249 	return NULL;
250 }
251 
252 static int __devinit max8925_regulator_probe(struct platform_device *pdev)
253 {
254 	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
255 	struct max8925_platform_data *pdata = chip->dev->platform_data;
256 	struct max8925_regulator_info *ri;
257 	struct regulator_dev *rdev;
258 
259 	ri = find_regulator_info(pdev->id);
260 	if (ri == NULL) {
261 		dev_err(&pdev->dev, "invalid regulator ID specified\n");
262 		return -EINVAL;
263 	}
264 	ri->i2c = chip->i2c;
265 	ri->chip = chip;
266 
267 	rdev = regulator_register(&ri->desc, &pdev->dev,
268 				  pdata->regulator[pdev->id], ri);
269 	if (IS_ERR(rdev)) {
270 		dev_err(&pdev->dev, "failed to register regulator %s\n",
271 				ri->desc.name);
272 		return PTR_ERR(rdev);
273 	}
274 
275 	platform_set_drvdata(pdev, rdev);
276 	return 0;
277 }
278 
279 static int __devexit max8925_regulator_remove(struct platform_device *pdev)
280 {
281 	struct regulator_dev *rdev = platform_get_drvdata(pdev);
282 
283 	platform_set_drvdata(pdev, NULL);
284 	regulator_unregister(rdev);
285 
286 	return 0;
287 }
288 
289 static struct platform_driver max8925_regulator_driver = {
290 	.driver		= {
291 		.name	= "max8925-regulator",
292 		.owner	= THIS_MODULE,
293 	},
294 	.probe		= max8925_regulator_probe,
295 	.remove		= __devexit_p(max8925_regulator_remove),
296 };
297 
298 static int __init max8925_regulator_init(void)
299 {
300 	return platform_driver_register(&max8925_regulator_driver);
301 }
302 subsys_initcall(max8925_regulator_init);
303 
304 static void __exit max8925_regulator_exit(void)
305 {
306 	platform_driver_unregister(&max8925_regulator_driver);
307 }
308 module_exit(max8925_regulator_exit);
309 
310 MODULE_LICENSE("GPL");
311 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
312 MODULE_DESCRIPTION("Regulator Driver for Maxim 8925 PMIC");
313 MODULE_ALIAS("platform:max8925-regulator");
314 
315