Re: [PATCH v5 20/28] fpga: dfl: add fpga bridge platform driver for FME

Alan Tull
2018-05-23T15:15:00Z

On Tue, May 1, 2018 at 9:50 PM, Wu Hao <hao.wu@intel.com> wrote:

Hi Hao,

> This patch adds fpga bridge platform driver for FPGA Management Engine.
> It implements the enable_set callback for fpga bridge.
>
> Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
> Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
> Signed-off-by: Shiva Rao <shiva.rao@intel.com>
> Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Acked-by: Alan Tull <atull@kernel.org>
> Acked-by: Moritz Fischer <mdf@kernel.org>
> ---
> v3: rename driver to fpga-dfl-fme-br
> remove useless dev_dbg in probe function.
> rebased due to fpga api change.
> v4: rename to dfl-fme-br and fix SPDX license issue
> include dfl-fme-pr.h instead of dfl-fme.h
> add Acked-by from Alan and Moritz
> v5: rebase due to API changes.
> defer port and its ops finding when really need.
> ---
> drivers/fpga/Kconfig | 6 +++
> drivers/fpga/Makefile | 1 +
> drivers/fpga/dfl-fme-br.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 121 insertions(+)
> create mode 100644 drivers/fpga/dfl-fme-br.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 89f76e8..a8f939a 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -156,6 +156,12 @@ config FPGA_DFL_FME_MGR
> help
> Say Y to enable FPGA Manager driver for FPGA Management Engine.
>
> +config FPGA_DFL_FME_BRIDGE
> + tristate "FPGA DFL FME Bridge Driver"
> + depends on FPGA_DFL_FME
> + help
> + Say Y to enable FPGA Bridge driver for FPGA Management Engine.
> +
> config FPGA_DFL_PCI
> tristate "FPGA Device Feature List (DFL) PCIe Device Driver"
> depends on PCI && FPGA_DFL
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index f82814a..75096e9 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -32,6 +32,7 @@ obj-$(CONFIG_OF_FPGA_REGION) += of-fpga-region.o
> obj-$(CONFIG_FPGA_DFL) += dfl.o
> obj-$(CONFIG_FPGA_DFL_FME) += dfl-fme.o
> obj-$(CONFIG_FPGA_DFL_FME_MGR) += dfl-fme-mgr.o
> +obj-$(CONFIG_FPGA_DFL_FME_BRIDGE) += dfl-fme-br.o
>
> dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o
>
> diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
> new file mode 100644
> index 0000000..5c51b08
> --- /dev/null
> +++ b/drivers/fpga/dfl-fme-br.c
> @@ -0,0 +1,114 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * FPGA Bridge Driver for FPGA Management Engine (FME)
> + *
> + * Copyright (C) 2017 Intel Corporation, Inc.
> + *
> + * Authors:
> + * Wu Hao <hao.wu@intel.com>
> + * Joseph Grecco <joe.grecco@intel.com>
> + * Enno Luebbers <enno.luebbers@intel.com>
> + * Tim Whisonant <tim.whisonant@intel.com>
> + * Ananda Ravuri <ananda.ravuri@intel.com>
> + * Henry Mitchel <henry.mitchel@intel.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/fpga/fpga-bridge.h>
> +
> +#include "dfl.h"
> +#include "dfl-fme-pr.h"
> +
> +struct fme_br_priv {
> + struct dfl_fme_br_pdata *pdata;
> + struct dfl_fpga_port_ops *port_ops;
> + struct platform_device *port_pdev;
> +};
> +
> +static int fme_bridge_enable_set(struct fpga_bridge *bridge, bool enable)
> +{
> + struct fme_br_priv *priv = bridge->priv;
> + struct platform_device *port_pdev;
> + struct dfl_fpga_port_ops *ops;
> +
> + if (!priv->port_pdev) {
> + port_pdev = dfl_fpga_cdev_find_port(priv->pdata->cdev,
> + &priv->pdata->port_id,
> + dfl_fpga_check_port_id);
> + if (!port_pdev)
> + return -ENODEV;
> +
> + priv->port_pdev = port_pdev;
> + }
> +
> + if (priv->port_pdev && !priv->port_ops) {
> + ops = dfl_fpga_get_port_ops(priv->port_pdev);
> + if (!ops || !ops->enable_set)
> + return -ENOENT;
> +
> + priv->port_ops = ops;
> + }

This is saving some pointers. Is it possible that the port_pdev or
port_ops could go away?

Also, the port ops routines probably should be named
dfl_fpga_port_ops_get/find_port/etc

Alan

> +
> + return priv->port_ops->enable_set(priv->port_pdev, enable);
> +}
> +
> +static const struct fpga_bridge_ops fme_bridge_ops = {
> + .enable_set = fme_bridge_enable_set,
> +};
> +
> +static int fme_br_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct fme_br_priv *priv;
> + struct fpga_bridge *br;
> + int ret;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->pdata = dev_get_platdata(dev);
> +
> + br = fpga_bridge_create(dev, "DFL FPGA FME Bridge",
> + &fme_bridge_ops, priv);
> + if (!br)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, br);
> +
> + ret = fpga_bridge_register(br);
> + if (ret)
> + fpga_bridge_free(br);
> +
> + return ret;
> +}
> +
> +static int fme_br_remove(struct platform_device *pdev)
> +{
> + struct fpga_bridge *br = platform_get_drvdata(pdev);
> + struct fme_br_priv *priv = br->priv;
> +
> + fpga_bridge_unregister(br);
> +
> + if (priv->port_pdev)
> + put_device(&priv->port_pdev->dev);
> + if (priv->port_ops)
> + dfl_fpga_put_port_ops(priv->port_ops);
> +
> + return 0;
> +}
> +
> +static struct platform_driver fme_br_driver = {
> + .driver = {
> + .name = DFL_FPGA_FME_BRIDGE,
> + },
> + .probe = fme_br_probe,
> + .remove = fme_br_remove,
> +};
> +
> +module_platform_driver(fme_br_driver);
> +
> +MODULE_DESCRIPTION("FPGA Bridge for DFL FPGA Management Engine");
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:dfl-fme-bridge");
> --
> 1.8.3.1
>