1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Regulator driver for STw4810/STw4811 VMMC regulator.
4 *
5 * Copyright (C) 2013 ST-Ericsson SA
6 * Written on behalf of Linaro for ST-Ericsson
7 *
8 * Author: Linus Walleij <linus.walleij@linaro.org>
9 */
10
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/mfd/stw481x.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/regulator/driver.h>
17 #include <linux/regulator/of_regulator.h>
18
19 static const unsigned int stw481x_vmmc_voltages[] = {
20 1800000,
21 1800000,
22 2850000,
23 3000000,
24 1850000,
25 2600000,
26 2700000,
27 3300000,
28 };
29
30 static const struct regulator_ops stw481x_vmmc_ops = {
31 .list_voltage = regulator_list_voltage_table,
32 .enable = regulator_enable_regmap,
33 .disable = regulator_disable_regmap,
34 .is_enabled = regulator_is_enabled_regmap,
35 .get_voltage_sel = regulator_get_voltage_sel_regmap,
36 .set_voltage_sel = regulator_set_voltage_sel_regmap,
37 };
38
39 static const struct regulator_desc vmmc_regulator = {
40 .name = "VMMC",
41 .id = 0,
42 .ops = &stw481x_vmmc_ops,
43 .type = REGULATOR_VOLTAGE,
44 .owner = THIS_MODULE,
45 .n_voltages = ARRAY_SIZE(stw481x_vmmc_voltages),
46 .volt_table = stw481x_vmmc_voltages,
47 .enable_time = 200, /* FIXME: look this up */
48 .enable_reg = STW_CONF1,
49 .enable_mask = STW_CONF1_PDN_VMMC | STW_CONF1_MMC_LS_STATUS,
50 .enable_val = STW_CONF1_PDN_VMMC,
51 .vsel_reg = STW_CONF1,
52 .vsel_mask = STW_CONF1_VMMC_MASK,
53 };
54
stw481x_vmmc_regulator_probe(struct platform_device * pdev)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 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
99 .of_match_table = stw481x_vmmc_match,
100 },
101 .probe = stw481x_vmmc_regulator_probe,
102 };
103
104 module_platform_driver(stw481x_vmmc_regulator_driver);
105