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1// SPDX-License-Identifier: GPL-2.02/* Copyright (C) 2018-2020 Broadcom */3 4#include <linux/device.h>5#include <linux/iopoll.h>6#include <linux/module.h>7#include <linux/of.h>8#include <linux/platform_device.h>9#include <linux/reset-controller.h>10 11#define BRCM_RESCAL_START 0x012#define BRCM_RESCAL_START_BIT BIT(0)13#define BRCM_RESCAL_CTRL 0x414#define BRCM_RESCAL_STATUS 0x815#define BRCM_RESCAL_STATUS_BIT BIT(0)16 17struct brcm_rescal_reset {18 void __iomem *base;19 struct device *dev;20 struct reset_controller_dev rcdev;21};22 23static int brcm_rescal_reset_set(struct reset_controller_dev *rcdev,24 unsigned long id)25{26 struct brcm_rescal_reset *data =27 container_of(rcdev, struct brcm_rescal_reset, rcdev);28 void __iomem *base = data->base;29 u32 reg;30 int ret;31 32 reg = readl(base + BRCM_RESCAL_START);33 writel(reg | BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);34 reg = readl(base + BRCM_RESCAL_START);35 if (!(reg & BRCM_RESCAL_START_BIT)) {36 dev_err(data->dev, "failed to start SATA/PCIe rescal\n");37 return -EIO;38 }39 40 ret = readl_poll_timeout(base + BRCM_RESCAL_STATUS, reg,41 (reg & BRCM_RESCAL_STATUS_BIT), 100, 1000);42 if (ret) {43 dev_err(data->dev, "time out on SATA/PCIe rescal\n");44 return ret;45 }46 47 reg = readl(base + BRCM_RESCAL_START);48 writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);49 50 dev_dbg(data->dev, "SATA/PCIe rescal success\n");51 52 return 0;53}54 55static int brcm_rescal_reset_xlate(struct reset_controller_dev *rcdev,56 const struct of_phandle_args *reset_spec)57{58 /* This is needed if #reset-cells == 0. */59 return 0;60}61 62static const struct reset_control_ops brcm_rescal_reset_ops = {63 .reset = brcm_rescal_reset_set,64};65 66static int brcm_rescal_reset_probe(struct platform_device *pdev)67{68 struct brcm_rescal_reset *data;69 70 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);71 if (!data)72 return -ENOMEM;73 74 data->base = devm_platform_ioremap_resource(pdev, 0);75 if (IS_ERR(data->base))76 return PTR_ERR(data->base);77 78 data->rcdev.owner = THIS_MODULE;79 data->rcdev.nr_resets = 1;80 data->rcdev.ops = &brcm_rescal_reset_ops;81 data->rcdev.of_node = pdev->dev.of_node;82 data->rcdev.of_xlate = brcm_rescal_reset_xlate;83 data->dev = &pdev->dev;84 85 return devm_reset_controller_register(&pdev->dev, &data->rcdev);86}87 88static const struct of_device_id brcm_rescal_reset_of_match[] = {89 { .compatible = "brcm,bcm7216-pcie-sata-rescal" },90 { },91};92MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match);93 94static struct platform_driver brcm_rescal_reset_driver = {95 .probe = brcm_rescal_reset_probe,96 .driver = {97 .name = "brcm-rescal-reset",98 .of_match_table = brcm_rescal_reset_of_match,99 }100};101module_platform_driver(brcm_rescal_reset_driver);102 103MODULE_AUTHOR("Broadcom");104MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller");105MODULE_LICENSE("GPL v2");106