1 /*
2  * Regulator driver for STw4810/STw4811 VMMC regulator.
3  *
4  * Copyright (C) 2013 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  *
7  * Author: Linus Walleij <linus.walleij@linaro.org>
8  *
9  * License terms: GNU General Public License (GPL) version 2
10  */
11 
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/mfd/stw481x.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/regulator/driver.h>
18 #include <linux/regulator/of_regulator.h>
19 
20 static const unsigned int stw481x_vmmc_voltages[] = {
21 	1800000,
22 	1800000,
23 	2850000,
24 	3000000,
25 	1850000,
26 	2600000,
27 	2700000,
28 	3300000,
29 };
30 
31 static struct regulator_ops stw481x_vmmc_ops = {
32 	.list_voltage = regulator_list_voltage_table,
33 	.enable      = regulator_enable_regmap,
34 	.disable     = regulator_disable_regmap,
35 	.is_enabled  = regulator_is_enabled_regmap,
36 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
37 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
38 };
39 
40 static struct regulator_desc vmmc_regulator = {
41 	.name = "VMMC",
42 	.id   = 0,
43 	.ops  = &stw481x_vmmc_ops,
44 	.type = REGULATOR_VOLTAGE,
45 	.owner = THIS_MODULE,
46 	.n_voltages = ARRAY_SIZE(stw481x_vmmc_voltages),
47 	.volt_table = stw481x_vmmc_voltages,
48 	.enable_time = 200, /* FIXME: look this up */
49 	.enable_reg = STW_CONF1,
50 	.enable_mask = STW_CONF1_PDN_VMMC,
51 	.vsel_reg = STW_CONF1,
52 	.vsel_mask = STW_CONF1_VMMC_MASK,
53 };
54 
55 static int stw481x_vmmc_regulator_probe(struct platform_device *pdev)
56 {
57 	struct stw481x *stw481x = dev_get_platdata(&pdev->dev);
58 	struct regulator_config config = { };
59 	struct regulator_dev *rdev;
60 	int ret;
61 
62 	/* First disable the external VMMC if it's active */
63 	ret = regmap_update_bits(stw481x->map, STW_CONF2,
64 				 STW_CONF2_VMMC_EXT, 0);
65 	if (ret) {
66 		dev_err(&pdev->dev, "could not disable external VMMC\n");
67 		return ret;
68 	}
69 
70 	/* Register VMMC regulator */
71 	config.dev = &pdev->dev;
72 	config.driver_data = stw481x;
73 	config.regmap = stw481x->map;
74 	config.of_node = pdev->dev.of_node;
75 	config.init_data = of_get_regulator_init_data(&pdev->dev,
76 						      pdev->dev.of_node,
77 						      &vmmc_regulator);
78 
79 	rdev = devm_regulator_register(&pdev->dev, &vmmc_regulator, &config);
80 	if (IS_ERR(rdev)) {
81 		dev_err(&pdev->dev,
82 			"error initializing STw481x VMMC regulator\n");
83 		return PTR_ERR(rdev);
84 	}
85 
86 	dev_info(&pdev->dev, "initialized STw481x VMMC regulator\n");
87 	return 0;
88 }
89 
90 static const struct of_device_id stw481x_vmmc_match[] = {
91 	{ .compatible = "st,stw481x-vmmc", },
92 	{},
93 };
94 
95 static struct platform_driver stw481x_vmmc_regulator_driver = {
96 	.driver = {
97 		.name  = "stw481x-vmmc-regulator",
98 		.of_match_table = stw481x_vmmc_match,
99 	},
100 	.probe = stw481x_vmmc_regulator_probe,
101 };
102 
103 module_platform_driver(stw481x_vmmc_regulator_driver);
104