/*
* 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 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);
static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
{
struct xlnx_pr_decoupler_data *priv;
int err;
struct resource *res;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->io_base = devm_ioremap_resource(&pdev->dev, res);
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)) {
dev_err(&pdev->dev, "input clock not found\n");
return PTR_ERR(priv->clk);
}
err = clk_prepare_enable(priv->clk);
if (err) {
dev_err(&pdev->dev, "unable to enable clock\n");
return err;
}
clk_disable(priv->clk);
err = fpga_bridge_register(&pdev->dev, "Xilinx PR Decoupler",
&xlnx_pr_decoupler_br_ops, priv);
if (err) {
dev_err(&pdev->dev, "unable to register Xilinx PR Decoupler");
clk_unprepare(priv->clk);
return err;
}
return 0;
}
static int 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(&pdev->dev);
clk_unprepare(p->clk);
return 0;
}
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 = of_match_ptr(xlnx_pr_decoupler_of_match),
},
};
module_platform_driver(xlnx_pr_decoupler_driver);
MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
MODULE_LICENSE("GPL v2");
