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/of_device.h> 12 #include <linux/regulator/driver.h> 13 #include <linux/regulator/machine.h> 14 #include <linux/regulator/of_regulator.h> 15 #include <linux/vexpress.h> 16 17 static int vexpress_regulator_get_voltage(struct regulator_dev *regdev) 18 { 19 unsigned int uV; 20 int err = regmap_read(regdev->regmap, 0, &uV); 21 22 return err ? err : uV; 23 } 24 25 static int vexpress_regulator_set_voltage(struct regulator_dev *regdev, 26 int min_uV, int max_uV, unsigned *selector) 27 { 28 return regmap_write(regdev->regmap, 0, min_uV); 29 } 30 31 static const struct regulator_ops vexpress_regulator_ops_ro = { 32 .get_voltage = vexpress_regulator_get_voltage, 33 }; 34 35 static const struct regulator_ops vexpress_regulator_ops = { 36 .get_voltage = vexpress_regulator_get_voltage, 37 .set_voltage = vexpress_regulator_set_voltage, 38 }; 39 40 static int vexpress_regulator_probe(struct platform_device *pdev) 41 { 42 struct regulator_desc *desc; 43 struct regulator_init_data *init_data; 44 struct regulator_config config = { }; 45 struct regulator_dev *rdev; 46 struct regmap *regmap; 47 48 desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL); 49 if (!desc) 50 return -ENOMEM; 51 52 regmap = devm_regmap_init_vexpress_config(&pdev->dev); 53 if (IS_ERR(regmap)) 54 return PTR_ERR(regmap); 55 56 desc->name = dev_name(&pdev->dev); 57 desc->type = REGULATOR_VOLTAGE; 58 desc->owner = THIS_MODULE; 59 desc->continuous_voltage_range = true; 60 61 init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node, 62 desc); 63 if (!init_data) 64 return -EINVAL; 65 66 init_data->constraints.apply_uV = 0; 67 if (init_data->constraints.min_uV && init_data->constraints.max_uV) 68 desc->ops = &vexpress_regulator_ops; 69 else 70 desc->ops = &vexpress_regulator_ops_ro; 71 72 config.regmap = regmap; 73 config.dev = &pdev->dev; 74 config.init_data = init_data; 75 config.of_node = pdev->dev.of_node; 76 77 rdev = devm_regulator_register(&pdev->dev, desc, &config); 78 if (IS_ERR(rdev)) 79 return PTR_ERR(rdev); 80 81 return 0; 82 } 83 84 static const struct of_device_id vexpress_regulator_of_match[] = { 85 { .compatible = "arm,vexpress-volt", }, 86 { } 87 }; 88 MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match); 89 90 static struct platform_driver vexpress_regulator_driver = { 91 .probe = vexpress_regulator_probe, 92 .driver = { 93 .name = DRVNAME, 94 .of_match_table = vexpress_regulator_of_match, 95 }, 96 }; 97 98 module_platform_driver(vexpress_regulator_driver); 99 100 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>"); 101 MODULE_DESCRIPTION("Versatile Express regulator"); 102 MODULE_LICENSE("GPL"); 103 MODULE_ALIAS("platform:vexpress-regulator"); 104