linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * FPGA Freeze Bridge Controller

 *

 *  Copyright (C) 2016 Altera Corporation. All rights reserved.

 */

#include <linux/delay.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/of_device.h>

#include <linux/module.h>

#include <linux/fpga/fpga-bridge.h>

​

#define FREEZE_CSR_STATUS_OFFSET        0

#define FREEZE_CSR_CTRL_OFFSET          4

#define FREEZE_CSR_ILLEGAL_REQ_OFFSET       8

#define FREEZE_CSR_REG_VERSION          12

​

#define FREEZE_CSR_SUPPORTED_VERSION        2

#define FREEZE_CSR_OFFICIAL_VERSION     0xad000003

​

#define FREEZE_CSR_STATUS_FREEZE_REQ_DONE   BIT(0)

#define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE BIT(1)

​

#define FREEZE_CSR_CTRL_FREEZE_REQ      BIT(0)

#define FREEZE_CSR_CTRL_RESET_REQ       BIT(1)

#define FREEZE_CSR_CTRL_UNFREEZE_REQ        BIT(2)

​

#define FREEZE_BRIDGE_NAME          "freeze"

​

struct altera_freeze_br_data {

    struct device *dev;

    void __iomem *base_addr;

    bool enable;

};

​

/*

 * Poll status until status bit is set or we have a timeout.

 */

static int altera_freeze_br_req_ack(struct altera_freeze_br_data *priv,

                    u32 timeout, u32 req_ack)

{

    struct device *dev = priv->dev;

    void __iomem *csr_illegal_req_addr = priv->base_addr +

                         FREEZE_CSR_ILLEGAL_REQ_OFFSET;

    u32 status, illegal, ctrl;

    int ret = -ETIMEDOUT;

​

    do {

        illegal = readl(csr_illegal_req_addr);

        if (illegal) {

            dev_err(dev, "illegal request detected 0x%x", illegal);

​

            writel(1, csr_illegal_req_addr);

​

            illegal = readl(csr_illegal_req_addr);

            if (illegal)

                dev_err(dev, "illegal request not cleared 0x%x",

                    illegal);

​

            ret = -EINVAL;

            break;

        }