// SPDX-License-Identifier: GPL-2.0-only /* * Oxford Semiconductor Reset Controller driver * * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com> * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com> * Copyright (C) 2009 Oxford Semiconductor Ltd */ #include <linux/err.h> #include <linux/init.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/reset-controller.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/types.h> #include <linux/regmap.h> #include <linux/mfd/syscon.h> /* Regmap offsets */ #define RST_SET_REGOFFSET 0x34 #define RST_CLR_REGOFFSET 0x38 struct oxnas_reset { struct regmap *regmap; struct reset_controller_dev rcdev; }; static int oxnas_reset_reset(struct reset_controller_dev *rcdev, unsigned long id) { struct oxnas_reset *data = container_of(rcdev, struct oxnas_reset, rcdev); regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id)); msleep(50); regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id)); return 0; } static int oxnas_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) { struct oxnas_reset *data = container_of(rcdev, struct oxnas_reset, rcdev); regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id)); return 0; } static int oxnas_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) { struct oxnas_reset *data = container_of(rcdev, struct oxnas_reset, rcdev); regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id)); return 0; } static const struct reset_control_ops oxnas_reset_ops = { .reset = oxnas_reset_reset, .assert = oxnas_reset_assert, .deassert = oxnas_reset_deassert, }; static const struct of_device_id oxnas_reset_dt_ids[] = { { .compatible = "oxsemi,ox810se-reset", }, { .compatible = "oxsemi,ox820-reset", }, { /* sentinel */ }, }; static int oxnas_reset_probe(struct platform_device *pdev) { struct oxnas_reset *data; struct device *parent; parent = pdev->dev.parent; if (!parent) { dev_err(&pdev->dev, "no parent\n"); return -ENODEV; } data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->regmap = syscon_node_to_regmap(parent->of_node); if (IS_ERR(data->regmap)) { dev_err(&pdev->dev, "failed to get parent regmap\n"); return PTR_ERR(data->regmap); } platform_set_drvdata(pdev, data); data->rcdev.owner = THIS_MODULE; data->rcdev.nr_resets = 32; data->rcdev.ops = &oxnas_reset_ops; data->rcdev.of_node = pdev->dev.of_node; return devm_reset_controller_register(&pdev->dev, &data->rcdev); } static struct platform_driver oxnas_reset_driver = { .probe = oxnas_reset_probe, .driver = { .name = "oxnas-reset", .of_match_table = oxnas_reset_dt_ids, }, }; builtin_platform_driver(oxnas_reset_driver);