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/mfd/syscon.h>
25 #include <linux/err.h>
26 #include <linux/io.h>
27 #include <linux/platform_device.h>
28 #include <linux/of.h>
29 #include <linux/of_address.h>
30 #include <linux/regmap.h>
31 #include <linux/regulator/driver.h>
32 #include <linux/regulator/of_regulator.h>
33 
34 struct anatop_regulator {
35 	const char *name;
36 	u32 control_reg;
37 	struct regmap *anatop;
38 	int vol_bit_shift;
39 	int vol_bit_width;
40 	int min_bit_val;
41 	int min_voltage;
42 	int max_voltage;
43 	struct regulator_desc rdesc;
44 	struct regulator_init_data *initdata;
45 };
46 
47 static int anatop_regmap_set_voltage_sel(struct regulator_dev *reg,
48 					unsigned selector)
49 {
50 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
51 	u32 val, mask;
52 
53 	if (!anatop_reg->control_reg)
54 		return -ENOTSUPP;
55 
56 	val = anatop_reg->min_bit_val + selector;
57 	dev_dbg(&reg->dev, "%s: calculated val %d\n", __func__, val);
58 	mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
59 		anatop_reg->vol_bit_shift;
60 	val <<= anatop_reg->vol_bit_shift;
61 	regmap_update_bits(anatop_reg->anatop, anatop_reg->control_reg,
62 				mask, val);
63 
64 	return 0;
65 }
66 
67 static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg)
68 {
69 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
70 	u32 val, mask;
71 
72 	if (!anatop_reg->control_reg)
73 		return -ENOTSUPP;
74 
75 	regmap_read(anatop_reg->anatop, anatop_reg->control_reg, &val);
76 	mask = ((1 << anatop_reg->vol_bit_width) - 1) <<
77 		anatop_reg->vol_bit_shift;
78 	val = (val & mask) >> anatop_reg->vol_bit_shift;
79 
80 	return val - anatop_reg->min_bit_val;
81 }
82 
83 static struct regulator_ops anatop_rops = {
84 	.set_voltage_sel = anatop_regmap_set_voltage_sel,
85 	.get_voltage_sel = anatop_regmap_get_voltage_sel,
86 	.list_voltage = regulator_list_voltage_linear,
87 	.map_voltage = regulator_map_voltage_linear,
88 };
89 
90 static int __devinit anatop_regulator_probe(struct platform_device *pdev)
91 {
92 	struct device *dev = &pdev->dev;
93 	struct device_node *np = dev->of_node;
94 	struct device_node *anatop_np;
95 	struct regulator_desc *rdesc;
96 	struct regulator_dev *rdev;
97 	struct anatop_regulator *sreg;
98 	struct regulator_init_data *initdata;
99 	struct regulator_config config = { };
100 	int ret = 0;
101 
102 	initdata = of_get_regulator_init_data(dev, np);
103 	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
104 	if (!sreg)
105 		return -ENOMEM;
106 	sreg->initdata = initdata;
107 	sreg->name = kstrdup(of_get_property(np, "regulator-name", NULL),
108 			     GFP_KERNEL);
109 	rdesc = &sreg->rdesc;
110 	memset(rdesc, 0, sizeof(*rdesc));
111 	rdesc->name = sreg->name;
112 	rdesc->ops = &anatop_rops;
113 	rdesc->type = REGULATOR_VOLTAGE;
114 	rdesc->owner = THIS_MODULE;
115 
116 	anatop_np = of_get_parent(np);
117 	if (!anatop_np)
118 		return -ENODEV;
119 	sreg->anatop = syscon_node_to_regmap(anatop_np);
120 	of_node_put(anatop_np);
121 	if (IS_ERR(sreg->anatop))
122 		return PTR_ERR(sreg->anatop);
123 
124 	ret = of_property_read_u32(np, "anatop-reg-offset",
125 				   &sreg->control_reg);
126 	if (ret) {
127 		dev_err(dev, "no anatop-reg-offset property set\n");
128 		goto anatop_probe_end;
129 	}
130 	ret = of_property_read_u32(np, "anatop-vol-bit-width",
131 				   &sreg->vol_bit_width);
132 	if (ret) {
133 		dev_err(dev, "no anatop-vol-bit-width property set\n");
134 		goto anatop_probe_end;
135 	}
136 	ret = of_property_read_u32(np, "anatop-vol-bit-shift",
137 				   &sreg->vol_bit_shift);
138 	if (ret) {
139 		dev_err(dev, "no anatop-vol-bit-shift property set\n");
140 		goto anatop_probe_end;
141 	}
142 	ret = of_property_read_u32(np, "anatop-min-bit-val",
143 				   &sreg->min_bit_val);
144 	if (ret) {
145 		dev_err(dev, "no anatop-min-bit-val property set\n");
146 		goto anatop_probe_end;
147 	}
148 	ret = of_property_read_u32(np, "anatop-min-voltage",
149 				   &sreg->min_voltage);
150 	if (ret) {
151 		dev_err(dev, "no anatop-min-voltage property set\n");
152 		goto anatop_probe_end;
153 	}
154 	ret = of_property_read_u32(np, "anatop-max-voltage",
155 				   &sreg->max_voltage);
156 	if (ret) {
157 		dev_err(dev, "no anatop-max-voltage property set\n");
158 		goto anatop_probe_end;
159 	}
160 
161 	rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage)
162 		/ 25000 + 1;
163 	rdesc->min_uV = sreg->min_voltage;
164 	rdesc->uV_step = 25000;
165 
166 	config.dev = &pdev->dev;
167 	config.init_data = initdata;
168 	config.driver_data = sreg;
169 	config.of_node = pdev->dev.of_node;
170 
171 	/* register regulator */
172 	rdev = regulator_register(rdesc, &config);
173 	if (IS_ERR(rdev)) {
174 		dev_err(dev, "failed to register %s\n",
175 			rdesc->name);
176 		ret = PTR_ERR(rdev);
177 		goto anatop_probe_end;
178 	}
179 
180 	platform_set_drvdata(pdev, rdev);
181 
182 anatop_probe_end:
183 	if (ret)
184 		kfree(sreg->name);
185 
186 	return ret;
187 }
188 
189 static int __devexit anatop_regulator_remove(struct platform_device *pdev)
190 {
191 	struct regulator_dev *rdev = platform_get_drvdata(pdev);
192 	struct anatop_regulator *sreg = rdev_get_drvdata(rdev);
193 	const char *name = sreg->name;
194 
195 	regulator_unregister(rdev);
196 	kfree(name);
197 
198 	return 0;
199 }
200 
201 static struct of_device_id __devinitdata of_anatop_regulator_match_tbl[] = {
202 	{ .compatible = "fsl,anatop-regulator", },
203 	{ /* end */ }
204 };
205 
206 static struct platform_driver anatop_regulator_driver = {
207 	.driver = {
208 		.name	= "anatop_regulator",
209 		.owner  = THIS_MODULE,
210 		.of_match_table = of_anatop_regulator_match_tbl,
211 	},
212 	.probe	= anatop_regulator_probe,
213 	.remove	= __devexit_p(anatop_regulator_remove),
214 };
215 
216 static int __init anatop_regulator_init(void)
217 {
218 	return platform_driver_register(&anatop_regulator_driver);
219 }
220 postcore_initcall(anatop_regulator_init);
221 
222 static void __exit anatop_regulator_exit(void)
223 {
224 	platform_driver_unregister(&anatop_regulator_driver);
225 }
226 module_exit(anatop_regulator_exit);
227 
228 MODULE_AUTHOR("Nancy Chen <Nancy.Chen@freescale.com>, "
229 	      "Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>");
230 MODULE_DESCRIPTION("ANATOP Regulator driver");
231 MODULE_LICENSE("GPL v2");
232