linux-imx

/*

 * Copyright (c) 2017, National Instruments Corp.

 * Copyright (c) 2017, Xilix Inc

 *

 * FPGA Bridge Driver for the Xilinx LogiCORE Partial Reconfiguration

 * Decoupler IP Core.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; version 2 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 */

​

#include <linux/clk.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 CTRL_CMD_DECOUPLE   BIT(0)

#define CTRL_CMD_COUPLE     0

#define CTRL_OFFSET     0

​

struct xlnx_pr_decoupler_data {

    void __iomem *io_base;

    struct clk *clk;

};

​

static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,

                       u32 offset, u32 val)

{

    writel(val, d->io_base + offset);

}

​

static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,

                    u32 offset)

{

    return readl(d->io_base + offset);

}

​

static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)

{

    int err;

    struct xlnx_pr_decoupler_data *priv = bridge->priv;

​

    err = clk_enable(priv->clk);

    if (err)

        return err;

​

    if (enable)

        xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);

    else

        xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);

​

    clk_disable(priv->clk);

​

    return 0;

}

​

static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)

{

    const struct xlnx_pr_decoupler_data *priv = bridge->priv;

    u32 status;

    int err;

​

    err = clk_enable(priv->clk);

    if (err)

        return err;

​

    status = readl(priv->io_base);

​

    clk_disable(priv->clk);

​

    return !status;

}

​

static const struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {

    .enable_set = xlnx_pr_decoupler_enable_set,

    .enable_show = xlnx_pr_decoupler_enable_show,

};

​

static const struct of_device_id xlnx_pr_decoupler_of_match[] = {

    { .compatible = "xlnx,pr-decoupler-1.00", },

    { .compatible = "xlnx,pr-decoupler", },

    {},

};

MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);