1 /*
2  * pbias-regulator.c
3  *
4  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
5  * Author: Balaji T K <balajitk@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation version 2.
10  *
11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12  * kind, whether express or implied; without even the implied warranty
13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/err.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/mfd/syscon.h>
21 #include <linux/platform_device.h>
22 #include <linux/regulator/driver.h>
23 #include <linux/regulator/machine.h>
24 #include <linux/regulator/of_regulator.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 
30 struct pbias_reg_info {
31 	u32 enable;
32 	u32 enable_mask;
33 	u32 vmode;
34 	unsigned int enable_time;
35 	char *name;
36 };
37 
38 struct pbias_regulator_data {
39 	struct regulator_desc desc;
40 	void __iomem *pbias_addr;
41 	unsigned int pbias_reg;
42 	struct regulator_dev *dev;
43 	struct regmap *syscon;
44 	const struct pbias_reg_info *info;
45 	int voltage;
46 };
47 
48 static int pbias_regulator_set_voltage(struct regulator_dev *dev,
49 			int min_uV, int max_uV, unsigned *selector)
50 {
51 	struct pbias_regulator_data *data = rdev_get_drvdata(dev);
52 	const struct pbias_reg_info *info = data->info;
53 	int ret, vmode;
54 
55 	if (min_uV <= 1800000)
56 		vmode = 0;
57 	else if (min_uV > 1800000)
58 		vmode = info->vmode;
59 
60 	ret = regmap_update_bits(data->syscon, data->pbias_reg,
61 						info->vmode, vmode);
62 
63 	return ret;
64 }
65 
66 static int pbias_regulator_get_voltage(struct regulator_dev *rdev)
67 {
68 	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);
69 	const struct pbias_reg_info *info = data->info;
70 	int value, voltage;
71 
72 	regmap_read(data->syscon, data->pbias_reg, &value);
73 	value &= info->vmode;
74 
75 	voltage = value ? 3000000 : 1800000;
76 
77 	return voltage;
78 }
79 
80 static int pbias_regulator_enable(struct regulator_dev *rdev)
81 {
82 	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);
83 	const struct pbias_reg_info *info = data->info;
84 	int ret;
85 
86 	ret = regmap_update_bits(data->syscon, data->pbias_reg,
87 					info->enable_mask, info->enable);
88 
89 	return ret;
90 }
91 
92 static int pbias_regulator_disable(struct regulator_dev *rdev)
93 {
94 	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);
95 	const struct pbias_reg_info *info = data->info;
96 	int ret;
97 
98 	ret = regmap_update_bits(data->syscon, data->pbias_reg,
99 						info->enable_mask, 0);
100 	return ret;
101 }
102 
103 static int pbias_regulator_is_enable(struct regulator_dev *rdev)
104 {
105 	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);
106 	const struct pbias_reg_info *info = data->info;
107 	int value;
108 
109 	regmap_read(data->syscon, data->pbias_reg, &value);
110 
111 	return (value & info->enable_mask) == info->enable_mask;
112 }
113 
114 static struct regulator_ops pbias_regulator_voltage_ops = {
115 	.set_voltage	= pbias_regulator_set_voltage,
116 	.get_voltage	= pbias_regulator_get_voltage,
117 	.enable		= pbias_regulator_enable,
118 	.disable	= pbias_regulator_disable,
119 	.is_enabled	= pbias_regulator_is_enable,
120 };
121 
122 static const struct pbias_reg_info pbias_mmc_omap2430 = {
123 	.enable = BIT(1),
124 	.enable_mask = BIT(1),
125 	.vmode = BIT(0),
126 	.enable_time = 100,
127 	.name = "pbias_mmc_omap2430"
128 };
129 
130 static const struct pbias_reg_info pbias_sim_omap3 = {
131 	.enable = BIT(9),
132 	.enable_mask = BIT(9),
133 	.vmode = BIT(8),
134 	.enable_time = 100,
135 	.name = "pbias_sim_omap3"
136 };
137 
138 static const struct pbias_reg_info pbias_mmc_omap4 = {
139 	.enable = BIT(26) | BIT(22),
140 	.enable_mask = BIT(26) | BIT(25) | BIT(22),
141 	.vmode = BIT(21),
142 	.enable_time = 100,
143 	.name = "pbias_mmc_omap4"
144 };
145 
146 static const struct pbias_reg_info pbias_mmc_omap5 = {
147 	.enable = BIT(27) | BIT(26),
148 	.enable_mask = BIT(27) | BIT(25) | BIT(26),
149 	.vmode = BIT(21),
150 	.enable_time = 100,
151 	.name = "pbias_mmc_omap5"
152 };
153 
154 static struct of_regulator_match pbias_matches[] = {
155 	{ .name = "pbias_mmc_omap2430", .driver_data = (void *)&pbias_mmc_omap2430},
156 	{ .name = "pbias_sim_omap3", .driver_data = (void *)&pbias_sim_omap3},
157 	{ .name = "pbias_mmc_omap4", .driver_data = (void *)&pbias_mmc_omap4},
158 	{ .name = "pbias_mmc_omap5", .driver_data = (void *)&pbias_mmc_omap5},
159 };
160 #define PBIAS_NUM_REGS	ARRAY_SIZE(pbias_matches)
161 
162 static const struct of_device_id pbias_of_match[] = {
163 	{ .compatible = "ti,pbias-omap", },
164 	{},
165 };
166 MODULE_DEVICE_TABLE(of, pbias_of_match);
167 
168 static int pbias_regulator_probe(struct platform_device *pdev)
169 {
170 	struct device_node *np = pdev->dev.of_node;
171 	struct pbias_regulator_data *drvdata;
172 	struct resource *res;
173 	struct regulator_config cfg = { };
174 	struct regmap *syscon;
175 	const struct pbias_reg_info *info;
176 	int ret = 0;
177 	int count, idx, data_idx = 0;
178 
179 	count = of_regulator_match(&pdev->dev, np, pbias_matches,
180 						PBIAS_NUM_REGS);
181 	if (count < 0)
182 		return count;
183 
184 	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct pbias_regulator_data)
185 			       * count, GFP_KERNEL);
186 	if (drvdata == NULL) {
187 		dev_err(&pdev->dev, "Failed to allocate device data\n");
188 		return -ENOMEM;
189 	}
190 
191 	syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
192 	if (IS_ERR(syscon))
193 		return PTR_ERR(syscon);
194 
195 	cfg.dev = &pdev->dev;
196 
197 	for (idx = 0; idx < PBIAS_NUM_REGS && data_idx < count; idx++) {
198 		if (!pbias_matches[idx].init_data ||
199 			!pbias_matches[idx].of_node)
200 			continue;
201 
202 		info = pbias_matches[idx].driver_data;
203 		if (!info)
204 			return -ENODEV;
205 
206 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
207 		if (!res)
208 			return -EINVAL;
209 
210 		drvdata[data_idx].pbias_reg = res->start;
211 		drvdata[data_idx].syscon = syscon;
212 		drvdata[data_idx].info = info;
213 		drvdata[data_idx].desc.name = info->name;
214 		drvdata[data_idx].desc.owner = THIS_MODULE;
215 		drvdata[data_idx].desc.type = REGULATOR_VOLTAGE;
216 		drvdata[data_idx].desc.ops = &pbias_regulator_voltage_ops;
217 		drvdata[data_idx].desc.n_voltages = 2;
218 		drvdata[data_idx].desc.enable_time = info->enable_time;
219 
220 		cfg.init_data = pbias_matches[idx].init_data;
221 		cfg.driver_data = &drvdata[data_idx];
222 		cfg.of_node = pbias_matches[idx].of_node;
223 
224 		drvdata[data_idx].dev = devm_regulator_register(&pdev->dev,
225 					&drvdata[data_idx].desc, &cfg);
226 		if (IS_ERR(drvdata[data_idx].dev)) {
227 			ret = PTR_ERR(drvdata[data_idx].dev);
228 			dev_err(&pdev->dev,
229 				"Failed to register regulator: %d\n", ret);
230 			goto err_regulator;
231 		}
232 		data_idx++;
233 	}
234 
235 	platform_set_drvdata(pdev, drvdata);
236 
237 err_regulator:
238 	return ret;
239 }
240 
241 static struct platform_driver pbias_regulator_driver = {
242 	.probe		= pbias_regulator_probe,
243 	.driver		= {
244 		.name		= "pbias-regulator",
245 		.owner		= THIS_MODULE,
246 		.of_match_table = of_match_ptr(pbias_of_match),
247 	},
248 };
249 
250 module_platform_driver(pbias_regulator_driver);
251 
252 MODULE_AUTHOR("Balaji T K <balajitk@ti.com>");
253 MODULE_DESCRIPTION("pbias voltage regulator");
254 MODULE_LICENSE("GPL");
255 MODULE_ALIAS("platform:pbias-regulator");
256