1 /*
2  * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
3  */
4 
5 /*
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10 
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15 
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <linux/slab.h>
22 #include <linux/device.h>
23 #include <linux/module.h>
24 #include <linux/err.h>
25 #include <linux/io.h>
26 #include <linux/platform_device.h>
27 #include <linux/of.h>
28 #include <linux/of_address.h>
29 #include <linux/mfd/anatop.h>
30 #include <linux/regulator/driver.h>
31 #include <linux/regulator/of_regulator.h>
32 
33 struct anatop_regulator {
34 	const char *name;
35 	u32 control_reg;
36 	struct anatop *mfd;
37 	int vol_bit_shift;
38 	int vol_bit_width;
39 	int min_bit_val;
40 	int min_voltage;
41 	int max_voltage;
42 	struct regulator_desc rdesc;
43 	struct regulator_init_data *initdata;
44 };
45 
46 static int anatop_set_voltage_sel(struct regulator_dev *reg, unsigned selector)
47 {
48 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
49 	u32 val, mask;
50 
51 	if (!anatop_reg->control_reg)
52 		return -ENOTSUPP;
53 
54 	val = anatop_reg->min_bit_val + selector;
55 	dev_dbg(&reg->dev, "%s: calculated val %d\n", __func__, val);
56 	mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
57 		anatop_reg->vol_bit_shift;
58 	val <<= anatop_reg->vol_bit_shift;
59 	anatop_write_reg(anatop_reg->mfd, anatop_reg->control_reg, val, mask);
60 
61 	return 0;
62 }
63 
64 static int anatop_get_voltage_sel(struct regulator_dev *reg)
65 {
66 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
67 	u32 val, mask;
68 
69 	if (!anatop_reg->control_reg)
70 		return -ENOTSUPP;
71 
72 	val = anatop_read_reg(anatop_reg->mfd, anatop_reg->control_reg);
73 	mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
74 		anatop_reg->vol_bit_shift;
75 	val = (val & mask) >> anatop_reg->vol_bit_shift;
76 
77 	return val - anatop_reg->min_bit_val;
78 }
79 
80 static struct regulator_ops anatop_rops = {
81 	.set_voltage_sel = anatop_set_voltage_sel,
82 	.get_voltage_sel = anatop_get_voltage_sel,
83 	.list_voltage = regulator_list_voltage_linear,
84 	.map_voltage = regulator_map_voltage_linear,
85 };
86 
87 static int __devinit anatop_regulator_probe(struct platform_device *pdev)
88 {
89 	struct device *dev = &pdev->dev;
90 	struct device_node *np = dev->of_node;
91 	struct regulator_desc *rdesc;
92 	struct regulator_dev *rdev;
93 	struct anatop_regulator *sreg;
94 	struct regulator_init_data *initdata;
95 	struct anatop *anatopmfd = dev_get_drvdata(pdev->dev.parent);
96 	struct regulator_config config = { };
97 	int ret = 0;
98 
99 	initdata = of_get_regulator_init_data(dev, np);
100 	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
101 	if (!sreg)
102 		return -ENOMEM;
103 	sreg->initdata = initdata;
104 	sreg->name = kstrdup(of_get_property(np, "regulator-name", NULL),
105 			     GFP_KERNEL);
106 	rdesc = &sreg->rdesc;
107 	memset(rdesc, 0, sizeof(*rdesc));
108 	rdesc->name = sreg->name;
109 	rdesc->ops = &anatop_rops;
110 	rdesc->type = REGULATOR_VOLTAGE;
111 	rdesc->owner = THIS_MODULE;
112 	sreg->mfd = anatopmfd;
113 	ret = of_property_read_u32(np, "anatop-reg-offset",
114 				   &sreg->control_reg);
115 	if (ret) {
116 		dev_err(dev, "no anatop-reg-offset property set\n");
117 		goto anatop_probe_end;
118 	}
119 	ret = of_property_read_u32(np, "anatop-vol-bit-width",
120 				   &sreg->vol_bit_width);
121 	if (ret) {
122 		dev_err(dev, "no anatop-vol-bit-width property set\n");
123 		goto anatop_probe_end;
124 	}
125 	ret = of_property_read_u32(np, "anatop-vol-bit-shift",
126 				   &sreg->vol_bit_shift);
127 	if (ret) {
128 		dev_err(dev, "no anatop-vol-bit-shift property set\n");
129 		goto anatop_probe_end;
130 	}
131 	ret = of_property_read_u32(np, "anatop-min-bit-val",
132 				   &sreg->min_bit_val);
133 	if (ret) {
134 		dev_err(dev, "no anatop-min-bit-val property set\n");
135 		goto anatop_probe_end;
136 	}
137 	ret = of_property_read_u32(np, "anatop-min-voltage",
138 				   &sreg->min_voltage);
139 	if (ret) {
140 		dev_err(dev, "no anatop-min-voltage property set\n");
141 		goto anatop_probe_end;
142 	}
143 	ret = of_property_read_u32(np, "anatop-max-voltage",
144 				   &sreg->max_voltage);
145 	if (ret) {
146 		dev_err(dev, "no anatop-max-voltage property set\n");
147 		goto anatop_probe_end;
148 	}
149 
150 	rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage)
151 		/ 25000 + 1;
152 	rdesc->min_uV = sreg->min_voltage;
153 	rdesc->uV_step = 25000;
154 
155 	config.dev = &pdev->dev;
156 	config.init_data = initdata;
157 	config.driver_data = sreg;
158 	config.of_node = pdev->dev.of_node;
159 
160 	/* register regulator */
161 	rdev = regulator_register(rdesc, &config);
162 	if (IS_ERR(rdev)) {
163 		dev_err(dev, "failed to register %s\n",
164 			rdesc->name);
165 		ret = PTR_ERR(rdev);
166 		goto anatop_probe_end;
167 	}
168 
169 	platform_set_drvdata(pdev, rdev);
170 
171 anatop_probe_end:
172 	if (ret)
173 		kfree(sreg->name);
174 
175 	return ret;
176 }
177 
178 static int __devexit anatop_regulator_remove(struct platform_device *pdev)
179 {
180 	struct regulator_dev *rdev = platform_get_drvdata(pdev);
181 	struct anatop_regulator *sreg = rdev_get_drvdata(rdev);
182 	const char *name = sreg->name;
183 
184 	regulator_unregister(rdev);
185 	kfree(name);
186 
187 	return 0;
188 }
189 
190 static struct of_device_id __devinitdata of_anatop_regulator_match_tbl[] = {
191 	{ .compatible = "fsl,anatop-regulator", },
192 	{ /* end */ }
193 };
194 
195 static struct platform_driver anatop_regulator_driver = {
196 	.driver = {
197 		.name	= "anatop_regulator",
198 		.owner  = THIS_MODULE,
199 		.of_match_table = of_anatop_regulator_match_tbl,
200 	},
201 	.probe	= anatop_regulator_probe,
202 	.remove	= __devexit_p(anatop_regulator_remove),
203 };
204 
205 static int __init anatop_regulator_init(void)
206 {
207 	return platform_driver_register(&anatop_regulator_driver);
208 }
209 postcore_initcall(anatop_regulator_init);
210 
211 static void __exit anatop_regulator_exit(void)
212 {
213 	platform_driver_unregister(&anatop_regulator_driver);
214 }
215 module_exit(anatop_regulator_exit);
216 
217 MODULE_AUTHOR("Nancy Chen <Nancy.Chen@freescale.com>, "
218 	      "Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>");
219 MODULE_DESCRIPTION("ANATOP Regulator driver");
220 MODULE_LICENSE("GPL v2");
221