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 16 struct 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. */ 22 static 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 43 static 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 50 static 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 79 static 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 84 static 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(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 } 104 105 static 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 } 136 137 static 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 }; 144 MODULE_DEVICE_TABLE(of, sun20i_regulator_of_match); 145 146 static 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 }; 153 module_platform_driver(sun20i_regulator_driver); 154 155 MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>"); 156 MODULE_DESCRIPTION("Allwinner D1 internal LDO driver"); 157 MODULE_LICENSE("GPL"); 158