Quelle  xilinx-pr-decoupler.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2017, National Instruments Corp.
 * Copyright (c) 2017, Xilinx Inc
 *
 * FPGA Bridge Driver for the Xilinx LogiCORE Partial Reconfiguration
 * Decoupler IP Core.
 */

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/fpga/fpga-bridge.h>

#define CTRL_CMD_DECOUPLE BIT(0)
#define CTRL_CMD_COUPLE  0
#define CTRL_OFFSET  0

struct xlnx_config_data {
 const char *name;
};

struct xlnx_pr_decoupler_data {
 const struct xlnx_config_data *ipconfig;
 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 = xlnx_pr_decouple_read(priv, CTRL_OFFSET);

 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 xlnx_config_data decoupler_config = {
 .name = "Xilinx PR Decoupler",
};

static const struct xlnx_config_data shutdown_config = {
 .name = "Xilinx DFX AXI Shutdown Manager",
};

static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
 { .compatible = "xlnx,pr-decoupler-1.00", .data = &decoupler_config },
 { .compatible = "xlnx,pr-decoupler", .data = &decoupler_config },
 { .compatible = "xlnx,dfx-axi-shutdown-manager-1.00",
     .data = &shutdown_config },
 { .compatible = "xlnx,dfx-axi-shutdown-manager",
     .data = &shutdown_config },
 {},
};
MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);

static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
{
 struct xlnx_pr_decoupler_data *priv;
 struct fpga_bridge *br;
 int err;

 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 if (!priv)
  return -ENOMEM;

 priv->ipconfig = device_get_match_data(&pdev->dev);

 priv->io_base = devm_platform_ioremap_resource(pdev, 0);
 if (IS_ERR(priv->io_base))
  return PTR_ERR(priv->io_base);

 priv->clk = devm_clk_get(&pdev->dev, "aclk");
 if (IS_ERR(priv->clk))
  return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
         "input clock not found\n");

 err = clk_prepare_enable(priv->clk);
 if (err) {
  dev_err(&pdev->dev, "unable to enable clock\n");
  return err;
 }

 clk_disable(priv->clk);

 br = fpga_bridge_register(&pdev->dev, priv->ipconfig->name,
      &xlnx_pr_decoupler_br_ops, priv);
 if (IS_ERR(br)) {
  err = PTR_ERR(br);
  dev_err(&pdev->dev, "unable to register %s",
   priv->ipconfig->name);
  goto err_clk;
 }

 platform_set_drvdata(pdev, br);

 return 0;

err_clk:
 clk_unprepare(priv->clk);

 return err;
}

static void xlnx_pr_decoupler_remove(struct platform_device *pdev)
{
 struct fpga_bridge *bridge = platform_get_drvdata(pdev);
 struct xlnx_pr_decoupler_data *p = bridge->priv;

 fpga_bridge_unregister(bridge);

 clk_unprepare(p->clk);
}

static struct platform_driver xlnx_pr_decoupler_driver = {
 .probe = xlnx_pr_decoupler_probe,
 .remove = xlnx_pr_decoupler_remove,
 .driver = {
  .name = "xlnx_pr_decoupler",
  .of_match_table = xlnx_pr_decoupler_of_match,
 },
};

module_platform_driver(xlnx_pr_decoupler_driver);

MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
MODULE_AUTHOR("Moritz Fischer ");
MODULE_AUTHOR("Michal Simek ");
MODULE_LICENSE("GPL v2");