diff options
Diffstat (limited to 'drivers/fpga/xilinx-pr-decoupler.c')
| -rw-r--r-- | drivers/fpga/xilinx-pr-decoupler.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c new file mode 100644 index 000000000000..e359930bebc8 --- /dev/null +++ b/drivers/fpga/xilinx-pr-decoupler.c @@ -0,0 +1,161 @@ +/* + * 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"); |