1// SPDX-License-Identifier: GPL-2.0-only
2//
3// Copyright (c) 2021-2022 Samuel Holland <samuel@sholland.org>
4//
5
6#include <linux/mfd/syscon.h>
7#include <linux/module.h>
8#include <linux/of.h>
9#include <linux/of_device.h>
10#include <linux/platform_device.h>
11#include <linux/regmap.h>
12#include <linux/regulator/driver.h>
13
14#define SUN20I_SYS_LDO_CTRL_REG 0x150
15
16struct sun20i_regulator_data {
17 const struct regulator_desc *descs;
18 unsigned int ndescs;
19};
20
21/* regulator_list_voltage_linear() modified for the non-integral uV_step. */
22static int sun20i_d1_system_ldo_list_voltage(struct regulator_dev *rdev,
23 unsigned int selector)
24{
25 const struct regulator_desc *desc = rdev->desc;
26 unsigned int fraction, uV;
27
28 if (selector >= desc->n_voltages)
29 return -EINVAL;
30
31 uV = desc->min_uV + (desc->uV_step * selector);
32 fraction = selector + (desc->min_uV % 4);
33
34 if (uV > 1606667)
35 uV += 6667;
36 else
37 fraction++;
38
39 /* Produce correctly-rounded absolute voltages. */
40 return uV + (fraction / 3);
41}
42
43static const struct regulator_ops sun20i_d1_system_ldo_ops = {
44 .list_voltage = sun20i_d1_system_ldo_list_voltage,
45 .map_voltage = regulator_map_voltage_ascend,
46 .set_voltage_sel = regulator_set_voltage_sel_regmap,
47 .get_voltage_sel = regulator_get_voltage_sel_regmap,
48};
49
50static const struct regulator_desc sun20i_d1_system_ldo_descs[] = {
51 {
52 .name = "ldoa",
53 .supply_name = "ldo-in",
54 .of_match = "ldoa",
55 .ops = &sun20i_d1_system_ldo_ops,
56 .type = REGULATOR_VOLTAGE,
57 .owner = THIS_MODULE,
58 .n_voltages = 32,
59 .min_uV = 1593333,
60 .uV_step = 13333, /* repeating */
61 .vsel_reg = SUN20I_SYS_LDO_CTRL_REG,
62 .vsel_mask = GENMASK(7, 0),
63 },
64 {
65 .name = "ldob",
66 .supply_name = "ldo-in",
67 .of_match = "ldob",
68 .ops = &sun20i_d1_system_ldo_ops,
69 .type = REGULATOR_VOLTAGE,
70 .owner = THIS_MODULE,
71 .n_voltages = 64,
72 .min_uV = 1166666,
73 .uV_step = 13333, /* repeating */
74 .vsel_reg = SUN20I_SYS_LDO_CTRL_REG,
75 .vsel_mask = GENMASK(15, 8),
76 },
77};
78
79static const struct sun20i_regulator_data sun20i_d1_system_ldos = {
80 .descs = sun20i_d1_system_ldo_descs,
81 .ndescs = ARRAY_SIZE(sun20i_d1_system_ldo_descs),
82};
83
84static struct regmap *sun20i_regulator_get_regmap(struct device *dev)
85{
86 struct regmap *regmap;
87
88 /*
89 * First try the syscon interface. The system control device is not
90 * compatible with "syscon", so fall back to getting the regmap from
91 * its platform device. This is ugly, but required for devicetree
92 * backward compatibility.
93 */
94 regmap = syscon_node_to_regmap(np: dev->parent->of_node);
95 if (!IS_ERR(ptr: regmap))
96 return regmap;
97
98 regmap = dev_get_regmap(dev: dev->parent, NULL);
99 if (regmap)
100 return regmap;
101
102 return ERR_PTR(error: -EPROBE_DEFER);
103}
104
105static int sun20i_regulator_probe(struct platform_device *pdev)
106{
107 const struct sun20i_regulator_data *data;
108 struct device *dev = &pdev->dev;
109 struct regulator_config config;
110 struct regmap *regmap;
111
112 data = of_device_get_match_data(dev);
113 if (!data)
114 return -EINVAL;
115
116 regmap = sun20i_regulator_get_regmap(dev);
117 if (IS_ERR(ptr: regmap))
118 return dev_err_probe(dev, err: PTR_ERR(ptr: regmap), fmt: "Failed to get regmap\n");
119
120 config = (struct regulator_config) {
121 .dev = dev,
122 .regmap = regmap,
123 };
124
125 for (unsigned int i = 0; i < data->ndescs; ++i) {
126 const struct regulator_desc *desc = &data->descs[i];
127 struct regulator_dev *rdev;
128
129 rdev = devm_regulator_register(dev, regulator_desc: desc, config: &config);
130 if (IS_ERR(ptr: rdev))
131 return PTR_ERR(ptr: rdev);
132 }
133
134 return 0;
135}
136
137static const struct of_device_id sun20i_regulator_of_match[] = {
138 {
139 .compatible = "allwinner,sun20i-d1-system-ldos",
140 .data = &sun20i_d1_system_ldos,
141 },
142 { },
143};
144MODULE_DEVICE_TABLE(of, sun20i_regulator_of_match);
145
146static struct platform_driver sun20i_regulator_driver = {
147 .probe = sun20i_regulator_probe,
148 .driver = {
149 .name = "sun20i-regulator",
150 .of_match_table = sun20i_regulator_of_match,
151 },
152};
153module_platform_driver(sun20i_regulator_driver);
154
155MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
156MODULE_DESCRIPTION("Allwinner D1 internal LDO driver");
157MODULE_LICENSE("GPL");
158

source code of linux/drivers/regulator/sun20i-regulator.c