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1// SPDX-License-Identifier: GPL-2.0-only2//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 0x15015 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 else37 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 not90 * compatible with "syscon", so fall back to getting the regmap from91 * its platform device. This is ugly, but required for devicetree92 * backward compatibility.93 */94 regmap = syscon_node_to_regmap(dev->parent->of_node);95 if (!IS_ERR(regmap))96 return regmap;97 98 regmap = dev_get_regmap(dev->parent, NULL);99 if (regmap)100 return regmap;101 102 return ERR_PTR(-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(regmap))118 return dev_err_probe(dev, PTR_ERR(regmap), "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, desc, &config);130 if (IS_ERR(rdev))131 return PTR_ERR(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