1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Copyright (C) 2012 ARM Limited 4 5 #define DRVNAME "vexpress-regulator" 6 #define pr_fmt(fmt) DRVNAME ": " fmt 7 8 #include <linux/device.h> 9 #include <linux/err.h> 10 #include <linux/module.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/platform_device.h> 13 #include <linux/regulator/driver.h> 14 #include <linux/regulator/machine.h> 15 #include <linux/regulator/of_regulator.h> 16 #include <linux/vexpress.h> 17 18 static int vexpress_regulator_get_voltage(struct regulator_dev *regdev) 19 { 20 unsigned int uV; 21 int err = regmap_read(regdev->regmap, 0, &uV); 22 23 return err ? err : uV; 24 } 25 26 static int vexpress_regulator_set_voltage(struct regulator_dev *regdev, 27 int min_uV, int max_uV, unsigned *selector) 28 { 29 return regmap_write(regdev->regmap, 0, min_uV); 30 } 31 32 static const struct regulator_ops vexpress_regulator_ops_ro = { 33 .get_voltage = vexpress_regulator_get_voltage, 34 }; 35 36 static const struct regulator_ops vexpress_regulator_ops = { 37 .get_voltage = vexpress_regulator_get_voltage, 38 .set_voltage = vexpress_regulator_set_voltage, 39 }; 40 41 static int vexpress_regulator_probe(struct platform_device *pdev) 42 { 43 struct regulator_desc *desc; 44 struct regulator_init_data *init_data; 45 struct regulator_config config = { }; 46 struct regulator_dev *rdev; 47 struct regmap *regmap; 48 49 desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL); 50 if (!desc) 51 return -ENOMEM; 52 53 regmap = devm_regmap_init_vexpress_config(&pdev->dev); 54 if (IS_ERR(regmap)) 55 return PTR_ERR(regmap); 56 57 desc->name = dev_name(&pdev->dev); 58 desc->type = REGULATOR_VOLTAGE; 59 desc->owner = THIS_MODULE; 60 desc->continuous_voltage_range = true; 61 62 init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node, 63 desc); 64 if (!init_data) 65 return -EINVAL; 66 67 init_data->constraints.apply_uV = 0; 68 if (init_data->constraints.min_uV && init_data->constraints.max_uV) 69 desc->ops = &vexpress_regulator_ops; 70 else 71 desc->ops = &vexpress_regulator_ops_ro; 72 73 config.regmap = regmap; 74 config.dev = &pdev->dev; 75 config.init_data = init_data; 76 config.of_node = pdev->dev.of_node; 77 78 rdev = devm_regulator_register(&pdev->dev, desc, &config); 79 return PTR_ERR_OR_ZERO(rdev); 80 } 81 82 static const struct of_device_id vexpress_regulator_of_match[] = { 83 { .compatible = "arm,vexpress-volt", }, 84 { } 85 }; 86 MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match); 87 88 static struct platform_driver vexpress_regulator_driver = { 89 .probe = vexpress_regulator_probe, 90 .driver = { 91 .name = DRVNAME, 92 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 93 .of_match_table = vexpress_regulator_of_match, 94 }, 95 }; 96 97 module_platform_driver(vexpress_regulator_driver); 98 99 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 100 MODULE_DESCRIPTION("Versatile Express regulator"); 101 MODULE_LICENSE("GPL"); 102 MODULE_ALIAS("platform:vexpress-regulator"); 103