Re: [PATCH v2 3/3] fpga manager: bus driver

From: atull
Date: Wed Oct 22 2014 - 18:29:39 EST

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On Wed, 22 Oct 2014, atull@xxxxxxxxxxxxxxxxxxxxx wrote:

> From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
>
> Support programming the fpga from device tree overlays.
>
> This patch adds one exported function to the core
> (fpga-mgr.c): of_fpga_mgr_dev_lookup
> Get pointer to fpga manager struct given a phandle.
>
> This code is dependent on Pantelis Antoniou's current work
> on Device Tree overlays, a method of dynamically altering
> the kernel's live Device Tree. The rest of the patchset was
> tested with recent for-next, but this 'bus driver' patch was
> tested with Pantelis's and Grant Likely's stuff that is in git
> (his git repo https://github.com/pantoniou/linux-beagle-track-mainline
> v3.17-rc2-115-gbc778b8 == dt-ng/bbb) plus some dtc fixups
> for compiling overlays.
>

Since this patch is dependent on a branch that would be hard
to put together, I have pushed a branch. If you happen to
have a cyclone5 board sitting around, you should be able to
load a FPGA from DT overlays using the steps below.

The branch name is 'dt-ng-overlays-v2.2'. The repo is at:
git://git.rocketboards.org/linux-socfpga-next.git

Alan

> Here's a simple example. Start with:
> * the altera-gpio driver built in to the kernel but not in the
> device tree.
> * raw fpga image at /lib/firmware/soc_system.rbf
> * Load appropriate device tree overlay in configfs by doing
> $ mkdir /config/device-tree/overlays/1
> $ echo socfpga_overlay.dtbo > /config/device-tree/overlays/1/path
> * This results in the FPGA getting programmed and the altera
> gpio driver getting probed.
> * To remove/clear FPGA image by putting the FPGA in reset,
> remove device tree overlay by doing:
> $ rmdir /config/device-tree/overlays/1
>
> Device tree overlay looks like this:
> /dts-v1/;
> /plugin/;
> / {
> fragment@0 {
> target-path="/soc";
> __overlay__ {
> #address-cells = <1>;
> #size-cells = <1>;
>
> bridge@0xff200000 {
> compatible = "fpga-mgr-bus", "simple-bus";
> reg = <0xff200000 0x200000>;
> clocks = <0x2 0x2>;
> clock-names = "h2f_lw_axi_clock", "f2h_sdram0_clock";
> #address-cells = <0x2>;
> #size-cells = <0x1>;
> ranges = <0x1 0x10040 0xff210040 0x20>;
>
> fpgamgr = <&hps_0_fpgamgr>;
> fpga-firmware = "soc_system.rbf";
>
> gpio@0x100010040 {
> compatible = "altr,pio-14.0", "altr,pio-1.0";
> reg = <0x1 0x10040 0x20>;
> clocks = <0x2>;
> altr,gpio-bank-width = <0x4>;
> resetvalue = <0x0>;
> #gpio-cells = <0x2>;
> gpio-controller;
> linux,phandle = <0x2d>;
> };
> };
> };
> };
> };
>
> Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
>
> v2: simplify of_fpga_mgr_dev_lookup to return NULL on failure
> move suspend/resume to fpga-mgr.c core
> support 'rmdir' to remove overlay
> ---
> drivers/fpga/Kconfig | 7 +++
> drivers/fpga/Makefile | 1 +
> drivers/fpga/bus.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/fpga/fpga-mgr.c | 23 +++++++++
> include/linux/fpga-mgr.h | 2 +
> 5 files changed, 157 insertions(+)
> create mode 100644 drivers/fpga/bus.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index e775b17..2bd6c83 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -18,4 +18,11 @@ config FPGA_MGR_SYSFS
> help
> FPGA Manager SysFS interface.
>
> +config FPGA_MGR_BUS
> + bool "FPGA Manager Bus"
> + depends on FPGA
> + help
> + FPGA Manager Bus interface. Allows loading FPGA images
> + from Device Tree or from other drivers.
> +
> endmenu
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index c8a676f..e39911f 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -6,5 +6,6 @@ fpga-mgr-core-y += fpga-mgr.o
>
> # Core FPGA Manager Framework
> obj-$(CONFIG_FPGA) += fpga-mgr-core.o
> +obj-$(CONFIG_FPGA_MGR_BUS) += bus.o
>
> # FPGA Manager Drivers
> diff --git a/drivers/fpga/bus.c b/drivers/fpga/bus.c
> new file mode 100644
> index 0000000..999346e
> --- /dev/null
> +++ b/drivers/fpga/bus.c
> @@ -0,0 +1,124 @@
> +/*
> + * FPGA Manager Bus Driver
> + *
> + * Copyright (C) 2013-2014 Altera Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +#include <linux/completion.h>
> +#include <linux/fs.h>
> +#include <linux/fpga-mgr.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/pm.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +
> +struct fpga_mgr_bus_priv {
> + struct device *dev;
> + struct device_node *np;
> + struct fpga_manager *mgr;
> + const char *path;
> +};
> +
> +static int fpga_mgr_bus_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device *dev = &pdev->dev;
> + struct fpga_mgr_bus_priv *priv;
> + const char *path;
> + struct fpga_manager *mgr;
> + int ret = 0;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + /* Find the FPGA Manager to associate with */
> + mgr = of_fpga_mgr_dev_lookup(np, "fpgamgr");
> + if (!mgr) {
> + dev_err(mgr->dev, "%s could not find fpga mgr\n", __func__);
> + return -ENODEV;
> + }
> +
> + /* Find the FPGA image on the firmware path */
> + of_property_read_string(np, "fpga-firmware", &path);
> +
> + ret = fpga_mgr_firmware_write(mgr, path);
> + if (ret != 0) {
> + dev_err(mgr->dev, "%s fpga mgr write failure\n", __func__);
> + return -EIO;
> + }
> +
> + priv->dev = dev;
> + priv->np = np;
> + priv->mgr = mgr;
> + priv->path = path;
> + platform_set_drvdata(pdev, priv);
> +
> + return 0;
> +}
> +
> +/* Called when the Device Tree overlay is removed */
> +static int fpga_mgr_bus_remove(struct platform_device *pdev)
> +{
> + struct fpga_mgr_bus_priv *priv = platform_get_drvdata(pdev);
> + struct fpga_manager *mgr = priv->mgr;
> +
> + return fpga_mgr_reset(mgr);
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id fpga_mgr_bus_of_match[] = {
> + { .compatible = "fpga-mgr-bus", },
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, fpga_mgr_bus_of_match);
> +#endif
> +
> +static struct platform_driver fpga_mgr_bus_driver = {
> + .probe = fpga_mgr_bus_probe,
> + .remove = fpga_mgr_bus_remove,
> + .driver = {
> + .name = "fpga_manager_bus",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(fpga_mgr_bus_of_match),
> + },
> +};
> +
> +static int __init fpga_mgr_bus_init(void)
> +{
> + return platform_driver_register(&fpga_mgr_bus_driver);
> +}
> +
> +static void __exit fpga_mgr_bus_exit(void)
> +{
> + platform_driver_unregister(&fpga_mgr_bus_driver);
> +}
> +
> +module_init(fpga_mgr_bus_init);
> +module_exit(fpga_mgr_bus_exit);
> +
> +MODULE_AUTHOR("Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Altera FPGA Manager Bus");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index 0c7236a..fed13a6 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -350,6 +350,29 @@ const struct attribute_group *fpga_mgr_groups[] = {
> #define fpga_mgr_groups NULL
> #endif /* CONFIG_FPGA_MGR_SYSFS */
>
> +/* Find the fpga manager that is pointed to by a phandle */
> +struct fpga_manager *of_fpga_mgr_dev_lookup(struct device_node *node,
> + const char *mgr_property)
> +{
> + struct fpga_manager *mgr;
> + struct device_node *mgr_node;
> +
> + mgr_node = of_parse_phandle(node, mgr_property, 0);
> + if (!mgr_node)
> + return NULL;
> +
> + list_for_each_entry(mgr, &fpga_manager_list, list)
> + if (mgr_node == mgr->np) {
> + of_node_put(mgr_node);
> + return mgr;
> + }
> +
> + of_node_put(mgr_node);
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(of_fpga_mgr_dev_lookup);
> +
> static int fpga_mgr_suspend(struct device *dev)
> {
> struct fpga_manager *mgr = dev_get_drvdata(dev);
> diff --git a/include/linux/fpga-mgr.h b/include/linux/fpga-mgr.h
> index 97c7e0b..abf2699 100644
> --- a/include/linux/fpga-mgr.h
> +++ b/include/linux/fpga-mgr.h
> @@ -110,6 +110,8 @@ int fpga_mgr_register(struct platform_device *pdev,
> struct fpga_manager_ops *mops,
> const char *name, void *priv);
> void fpga_mgr_remove(struct platform_device *pdev);
> +struct fpga_manager *of_fpga_mgr_dev_lookup(struct device_node *node,
> + const char *mgr_property);
>
> #endif /* CONFIG_FPGA */
> #endif /*_LINUX_FPGA_MGR_H */
> --
> 1.7.9.5
>
>
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Next message: James Hogan: "Re: [PATCH] mips: add arch_trigger_all_cpu_backtrace() function"
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In reply to: atull: "[PATCH v2 3/3] fpga manager: bus driver"
Next in thread: atull: "[PATCH v2 1/3] fpga manager: add sysfs interface document"
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