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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Reset driver for the StarFive JH7100 SoC4 *5 * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>6 */7 8#include <linux/mod_devicetable.h>9#include <linux/platform_device.h>10 11#include "reset-starfive-jh71x0.h"12 13#include <dt-bindings/reset/starfive-jh7100.h>14 15/* register offsets */16#define JH7100_RESET_ASSERT0 0x0017#define JH7100_RESET_ASSERT1 0x0418#define JH7100_RESET_ASSERT2 0x0819#define JH7100_RESET_ASSERT3 0x0c20#define JH7100_RESET_STATUS0 0x1021#define JH7100_RESET_STATUS1 0x1422#define JH7100_RESET_STATUS2 0x1823#define JH7100_RESET_STATUS3 0x1c24 25/*26 * Writing a 1 to the n'th bit of the m'th ASSERT register asserts27 * line 32m + n, and writing a 0 deasserts the same line.28 * Most reset lines have their status inverted so a 0 bit in the STATUS29 * register means the line is asserted and a 1 means it's deasserted. A few30 * lines don't though, so store the expected value of the status registers when31 * all lines are asserted.32 */33static const u32 jh7100_reset_asserted[4] = {34 /* STATUS0 */35 BIT(JH7100_RST_U74 % 32) |36 BIT(JH7100_RST_VP6_DRESET % 32) |37 BIT(JH7100_RST_VP6_BRESET % 32),38 /* STATUS1 */39 BIT(JH7100_RST_HIFI4_DRESET % 32) |40 BIT(JH7100_RST_HIFI4_BRESET % 32),41 /* STATUS2 */42 BIT(JH7100_RST_E24 % 32),43 /* STATUS3 */44 0,45};46 47static int __init jh7100_reset_probe(struct platform_device *pdev)48{49 void __iomem *base = devm_platform_ioremap_resource(pdev, 0);50 51 if (IS_ERR(base))52 return PTR_ERR(base);53 54 return reset_starfive_jh71x0_register(&pdev->dev, pdev->dev.of_node,55 base + JH7100_RESET_ASSERT0,56 base + JH7100_RESET_STATUS0,57 jh7100_reset_asserted,58 JH7100_RSTN_END,59 THIS_MODULE);60}61 62static const struct of_device_id jh7100_reset_dt_ids[] = {63 { .compatible = "starfive,jh7100-reset" },64 { /* sentinel */ }65};66 67static struct platform_driver jh7100_reset_driver = {68 .driver = {69 .name = "jh7100-reset",70 .of_match_table = jh7100_reset_dt_ids,71 .suppress_bind_attrs = true,72 },73};74builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe);75