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

[Alan Tull]

On Tue, May 1, 2018 at 9:50 PM, Wu Hao <hao.wu@xxxxxxxxx> 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@xxxxxxxxx>
> Signed-off-by: Enno Luebbers <enno.luebbers@xxxxxxxxx>
> Signed-off-by: Shiva Rao <shiva.rao@xxxxxxxxx>
> Signed-off-by: Christopher Rauer <christopher.rauer@xxxxxxxxx>
> Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
> Acked-by: Alan Tull <atull@xxxxxxxxxx>
> Acked-by: Moritz Fischer <mdf@xxxxxxxxxx>
> ---
> 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@xxxxxxxxx>
> + *   Joseph Grecco <joe.grecco@xxxxxxxxx>
> + *   Enno Luebbers <enno.luebbers@xxxxxxxxx>
> + *   Tim Whisonant <tim.whisonant@xxxxxxxxx>
> + *   Ananda Ravuri <ananda.ravuri@xxxxxxxxx>
> + *   Henry Mitchel <henry.mitchel@xxxxxxxxx>
> + */
> +
> +#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
>