[PATCH v2 3/3] fpga manager: bus driver
From: atull
Date: Wed Oct 22 2014 - 15:57:13 EST
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.
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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