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