add FPGA manager core

API to support programming FPGA's.

The following functions are exported as GPL:
* fpga_mgr_buf_load
   Load fpga from image in buffer

* fpga_mgr_firmware_load
   Request firmware and load it to the FPGA.

* fpga_mgr_register
* fpga_mgr_unregister
   FPGA device drivers can be added by calling
   fpga_mgr_register() to register a set of
   fpga_manager_ops to do device specific stuff.

* of_fpga_mgr_get
* fpga_mgr_put
   Get/put a reference to a fpga manager.

The following sysfs files are created:
* /sys/class/fpga_manager/<fpga>/name
  Name of low level driver.

* /sys/class/fpga_manager/<fpga>/state
  State of fpga manager

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/Kconfig

@@ -192,4 +192,6 @@ source "drivers/hwtracing/stm/Kconfig"
 
 source "drivers/hwtracing/intel_th/Kconfig"
 
+source "drivers/fpga/Kconfig"
+
 endmenu

drivers/Makefile

@@ -169,3 +169,4 @@ obj-y				+= hwtracing/intel_th/
 obj-$(CONFIG_STM)		+= hwtracing/stm/
 obj-$(CONFIG_ANDROID)		+= android/
 obj-$(CONFIG_NVMEM)		+= nvmem/
+obj-$(CONFIG_FPGA)		+= fpga/

drivers/fpga/Kconfig

@@ -0,0 +1,14 @@
+#
+# FPGA framework configuration
+#
+
+menu "FPGA Configuration Support"
+
+config FPGA
+	tristate "FPGA Configuration Framework"
+	help
+	  Say Y here if you want support for configuring FPGAs from the
+	  kernel.  The FPGA framework adds a FPGA manager class and FPGA
+	  manager drivers.
+
+endmenu

drivers/fpga/Makefile

@@ -0,0 +1,8 @@
+#
+# Makefile for the fpga framework and fpga manager drivers.
+#
+
+# Core FPGA Manager Framework
+obj-$(CONFIG_FPGA)			+= fpga-mgr.o
+
+# FPGA Manager Drivers

drivers/fpga/fpga-mgr.c

@@ -0,0 +1,382 @@
+/*
+ * FPGA Manager Core
+ *
+ *  Copyright (C) 2013-2015 Altera Corporation
+ *
+ * With code from the mailing list:
+ * Copyright (C) 2013 Xilinx, Inc.
+ *
+ * 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/firmware.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+static DEFINE_IDA(fpga_mgr_ida);
+static struct class *fpga_mgr_class;
+
+/**
+ * fpga_mgr_buf_load - load fpga from image in buffer
+ * @mgr:	fpga manager
+ * @flags:	flags setting fpga confuration modes
+ * @buf:	buffer contain fpga image
+ * @count:	byte count of buf
+ *
+ * Step the low level fpga manager through the device-specific steps of getting
+ * an FPGA ready to be configured, writing the image to it, then doing whatever
+ * post-configuration steps necessary.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, const char *buf,
+		      size_t count)
+{
+	struct device *dev = &mgr->dev;
+	int ret;
+
+	if (!mgr)
+		return -ENODEV;
+
+	/*
+	 * Call the low level driver's write_init function.  This will do the
+	 * device-specific things to get the FPGA into the state where it is
+	 * ready to receive an FPGA image.
+	 */
+	mgr->state = FPGA_MGR_STATE_WRITE_INIT;
+	ret = mgr->mops->write_init(mgr, flags, buf, count);
+	if (ret) {
+		dev_err(dev, "Error preparing FPGA for writing\n");
+		mgr->state = FPGA_MGR_STATE_WRITE_INIT_ERR;
+		return ret;
+	}
+
+	/*
+	 * Write the FPGA image to the FPGA.
+	 */
+	mgr->state = FPGA_MGR_STATE_WRITE;
+	ret = mgr->mops->write(mgr, buf, count);
+	if (ret) {
+		dev_err(dev, "Error while writing image data to FPGA\n");
+		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
+		return ret;
+	}
+
+	/*
+	 * After all the FPGA image has been written, do the device specific
+	 * steps to finish and set the FPGA into operating mode.
+	 */
+	mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE;
+	ret = mgr->mops->write_complete(mgr, flags);
+	if (ret) {
+		dev_err(dev, "Error after writing image data to FPGA\n");
+		mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE_ERR;
+		return ret;
+	}
+	mgr->state = FPGA_MGR_STATE_OPERATING;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_buf_load);
+
+/**
+ * fpga_mgr_firmware_load - request firmware and load to fpga
+ * @mgr:	fpga manager
+ * @flags:	flags setting fpga confuration modes
+ * @image_name:	name of image file on the firmware search path
+ *
+ * Request an FPGA image using the firmware class, then write out to the FPGA.
+ * Update the state before each step to provide info on what step failed if
+ * there is a failure.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int fpga_mgr_firmware_load(struct fpga_manager *mgr, u32 flags,
+			   const char *image_name)
+{
+	struct device *dev = &mgr->dev;
+	const struct firmware *fw;
+	int ret;
+
+	if (!mgr)
+		return -ENODEV;
+
+	dev_info(dev, "writing %s to %s\n", image_name, mgr->name);
+
+	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
+
+	ret = request_firmware(&fw, image_name, dev);
+	if (ret) {
+		mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
+		dev_err(dev, "Error requesting firmware %s\n", image_name);
+		return ret;
+	}
+
+	ret = fpga_mgr_buf_load(mgr, flags, fw->data, fw->size);
+	if (ret)
+		return ret;
+
+	release_firmware(fw);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load);
+
+static const char * const state_str[] = {
+	[FPGA_MGR_STATE_UNKNOWN] =		"unknown",
+	[FPGA_MGR_STATE_POWER_OFF] =		"power off",
+	[FPGA_MGR_STATE_POWER_UP] =		"power up",
+	[FPGA_MGR_STATE_RESET] =		"reset",
+
+	/* requesting FPGA image from firmware */
+	[FPGA_MGR_STATE_FIRMWARE_REQ] =		"firmware request",
+	[FPGA_MGR_STATE_FIRMWARE_REQ_ERR] =	"firmware request error",
+
+	/* Preparing FPGA to receive image */
+	[FPGA_MGR_STATE_WRITE_INIT] =		"write init",
+	[FPGA_MGR_STATE_WRITE_INIT_ERR] =	"write init error",
+
+	/* Writing image to FPGA */
+	[FPGA_MGR_STATE_WRITE] =		"write",
+	[FPGA_MGR_STATE_WRITE_ERR] =		"write error",
+
+	/* Finishing configuration after image has been written */
+	[FPGA_MGR_STATE_WRITE_COMPLETE] =	"write complete",
+	[FPGA_MGR_STATE_WRITE_COMPLETE_ERR] =	"write complete error",
+
+	/* FPGA reports to be in normal operating mode */
+	[FPGA_MGR_STATE_OPERATING] =		"operating",
+};
+
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+
+	return sprintf(buf, "%s\n", mgr->name);
+}
+
+static ssize_t state_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+
+	return sprintf(buf, "%s\n", state_str[mgr->state]);
+}
+
+static DEVICE_ATTR_RO(name);
+static DEVICE_ATTR_RO(state);
+
+static struct attribute *fpga_mgr_attrs[] = {
+	&dev_attr_name.attr,
+	&dev_attr_state.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(fpga_mgr);
+
+static int fpga_mgr_of_node_match(struct device *dev, const void *data)
+{
+	return dev->of_node == data;
+}
+
+/**
+ * of_fpga_mgr_get - get an exclusive reference to a fpga mgr
+ * @node:	device node
+ *
+ * Given a device node, get an exclusive reference to a fpga mgr.
+ *
+ * Return: fpga manager struct or IS_ERR() condition containing error code.
+ */
+struct fpga_manager *of_fpga_mgr_get(struct device_node *node)
+{
+	struct fpga_manager *mgr;
+	struct device *dev;
+
+	if (!node)
+		return ERR_PTR(-EINVAL);
+
+	dev = class_find_device(fpga_mgr_class, NULL, node,
+				fpga_mgr_of_node_match);
+	if (!dev)
+		return ERR_PTR(-ENODEV);
+
+	mgr = to_fpga_manager(dev);
+	put_device(dev);
+	if (!mgr)
+		return ERR_PTR(-ENODEV);
+
+	/* Get exclusive use of fpga manager */
+	if (!mutex_trylock(&mgr->ref_mutex))
+		return ERR_PTR(-EBUSY);
+
+	if (!try_module_get(THIS_MODULE)) {
+		mutex_unlock(&mgr->ref_mutex);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return mgr;
+}
+EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
+
+/**
+ * fpga_mgr_put - release a reference to a fpga manager
+ * @mgr:	fpga manager structure
+ */
+void fpga_mgr_put(struct fpga_manager *mgr)
+{
+	if (mgr) {
+		module_put(THIS_MODULE);
+		mutex_unlock(&mgr->ref_mutex);
+	}
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_put);
+
+/**
+ * fpga_mgr_register - register a low level fpga manager driver
+ * @dev:	fpga manager device from pdev
+ * @name:	fpga manager name
+ * @mops:	pointer to structure of fpga manager ops
+ * @priv:	fpga manager private data
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int fpga_mgr_register(struct device *dev, const char *name,
+		      const struct fpga_manager_ops *mops,
+		      void *priv)
+{
+	struct fpga_manager *mgr;
+	const char *dt_label;
+	int id, ret;
+
+	if (!mops || !mops->write_init || !mops->write ||
+	    !mops->write_complete || !mops->state) {
+		dev_err(dev, "Attempt to register without fpga_manager_ops\n");
+		return -EINVAL;
+	}
+
+	if (!name || !strlen(name)) {
+		dev_err(dev, "Attempt to register with no name!\n");
+		return -EINVAL;
+	}
+
+	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
+	if (!mgr)
+		return -ENOMEM;
+
+	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		ret = id;
+		goto error_kfree;
+	}
+
+	mutex_init(&mgr->ref_mutex);
+
+	mgr->name = name;
+	mgr->mops = mops;
+	mgr->priv = priv;
+
+	/*
+	 * Initialize framework state by requesting low level driver read state
+	 * from device.  FPGA may be in reset mode or may have been programmed
+	 * by bootloader or EEPROM.
+	 */
+	mgr->state = mgr->mops->state(mgr);
+
+	device_initialize(&mgr->dev);
+	mgr->dev.class = fpga_mgr_class;
+	mgr->dev.parent = dev;
+	mgr->dev.of_node = dev->of_node;
+	mgr->dev.id = id;
+	dev_set_drvdata(dev, mgr);
+
+	dt_label = of_get_property(mgr->dev.of_node, "label", NULL);
+	if (dt_label)
+		ret = dev_set_name(&mgr->dev, "%s", dt_label);
+	else
+		ret = dev_set_name(&mgr->dev, "fpga%d", id);
+
+	ret = device_add(&mgr->dev);
+	if (ret)
+		goto error_device;
+
+	dev_info(&mgr->dev, "%s registered\n", mgr->name);
+
+	return 0;
+
+error_device:
+	ida_simple_remove(&fpga_mgr_ida, id);
+error_kfree:
+	kfree(mgr);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_register);
+
+/**
+ * fpga_mgr_unregister - unregister a low level fpga manager driver
+ * @dev:	fpga manager device from pdev
+ */
+void fpga_mgr_unregister(struct device *dev)
+{
+	struct fpga_manager *mgr = dev_get_drvdata(dev);
+
+	dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);
+
+	/*
+	 * If the low level driver provides a method for putting fpga into
+	 * a desired state upon unregister, do it.
+	 */
+	if (mgr->mops->fpga_remove)
+		mgr->mops->fpga_remove(mgr);
+
+	device_unregister(&mgr->dev);
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
+
+static void fpga_mgr_dev_release(struct device *dev)
+{
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+
+	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
+	kfree(mgr);
+}
+
+static int __init fpga_mgr_class_init(void)
+{
+	pr_info("FPGA manager framework\n");
+
+	fpga_mgr_class = class_create(THIS_MODULE, "fpga_manager");
+	if (IS_ERR(fpga_mgr_class))
+		return PTR_ERR(fpga_mgr_class);
+
+	fpga_mgr_class->dev_groups = fpga_mgr_groups;
+	fpga_mgr_class->dev_release = fpga_mgr_dev_release;
+
+	return 0;
+}
+
+static void __exit fpga_mgr_class_exit(void)
+{
+	class_destroy(fpga_mgr_class);
+	ida_destroy(&fpga_mgr_ida);
+}
+
+MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
+MODULE_DESCRIPTION("FPGA manager framework");
+MODULE_LICENSE("GPL v2");
+
+subsys_initcall(fpga_mgr_class_init);
+module_exit(fpga_mgr_class_exit);

include/linux/fpga/fpga-mgr.h

@@ -0,0 +1,127 @@
+/*
+ * FPGA Framework
+ *
+ *  Copyright (C) 2013-2015 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/mutex.h>
+#include <linux/platform_device.h>
+
+#ifndef _LINUX_FPGA_MGR_H
+#define _LINUX_FPGA_MGR_H
+
+struct fpga_manager;
+
+/**
+ * enum fpga_mgr_states - fpga framework states
+ * @FPGA_MGR_STATE_UNKNOWN: can't determine state
+ * @FPGA_MGR_STATE_POWER_OFF: FPGA power is off
+ * @FPGA_MGR_STATE_POWER_UP: FPGA reports power is up
+ * @FPGA_MGR_STATE_RESET: FPGA in reset state
+ * @FPGA_MGR_STATE_FIRMWARE_REQ: firmware request in progress
+ * @FPGA_MGR_STATE_FIRMWARE_REQ_ERR: firmware request failed
+ * @FPGA_MGR_STATE_WRITE_INIT: preparing FPGA for programming
+ * @FPGA_MGR_STATE_WRITE_INIT_ERR: Error during WRITE_INIT stage
+ * @FPGA_MGR_STATE_WRITE: writing image to FPGA
+ * @FPGA_MGR_STATE_WRITE_ERR: Error while writing FPGA
+ * @FPGA_MGR_STATE_WRITE_COMPLETE: Doing post programming steps
+ * @FPGA_MGR_STATE_WRITE_COMPLETE_ERR: Error during WRITE_COMPLETE
+ * @FPGA_MGR_STATE_OPERATING: FPGA is programmed and operating
+ */
+enum fpga_mgr_states {
+	/* default FPGA states */
+	FPGA_MGR_STATE_UNKNOWN,
+	FPGA_MGR_STATE_POWER_OFF,
+	FPGA_MGR_STATE_POWER_UP,
+	FPGA_MGR_STATE_RESET,
+
+	/* getting an image for loading */
+	FPGA_MGR_STATE_FIRMWARE_REQ,
+	FPGA_MGR_STATE_FIRMWARE_REQ_ERR,
+
+	/* write sequence: init, write, complete */
+	FPGA_MGR_STATE_WRITE_INIT,
+	FPGA_MGR_STATE_WRITE_INIT_ERR,
+	FPGA_MGR_STATE_WRITE,
+	FPGA_MGR_STATE_WRITE_ERR,
+	FPGA_MGR_STATE_WRITE_COMPLETE,
+	FPGA_MGR_STATE_WRITE_COMPLETE_ERR,
+
+	/* fpga is programmed and operating */
+	FPGA_MGR_STATE_OPERATING,
+};
+
+/*
+ * FPGA Manager flags
+ * FPGA_MGR_PARTIAL_RECONFIG: do partial reconfiguration if supported
+ */
+#define FPGA_MGR_PARTIAL_RECONFIG	BIT(0)
+
+/**
+ * struct fpga_manager_ops - ops for low level fpga manager drivers
+ * @state: returns an enum value of the FPGA's state
+ * @write_init: prepare the FPGA to receive confuration data
+ * @write: write count bytes of configuration data to the FPGA
+ * @write_complete: set FPGA to operating state after writing is done
+ * @fpga_remove: optional: Set FPGA into a specific state during driver remove
+ *
+ * fpga_manager_ops are the low level functions implemented by a specific
+ * fpga manager driver.  The optional ones are tested for NULL before being
+ * called, so leaving them out is fine.
+ */
+struct fpga_manager_ops {
+	enum fpga_mgr_states (*state)(struct fpga_manager *mgr);
+	int (*write_init)(struct fpga_manager *mgr, u32 flags,
+			  const char *buf, size_t count);
+	int (*write)(struct fpga_manager *mgr, const char *buf, size_t count);
+	int (*write_complete)(struct fpga_manager *mgr, u32 flags);
+	void (*fpga_remove)(struct fpga_manager *mgr);
+};
+
+/**
+ * struct fpga_manager - fpga manager structure
+ * @name: name of low level fpga manager
+ * @dev: fpga manager device
+ * @ref_mutex: only allows one reference to fpga manager
+ * @state: state of fpga manager
+ * @mops: pointer to struct of fpga manager ops
+ * @priv: low level driver private date
+ */
+struct fpga_manager {
+	const char *name;
+	struct device dev;
+	struct mutex ref_mutex;
+	enum fpga_mgr_states state;
+	const struct fpga_manager_ops *mops;
+	void *priv;
+};
+
+#define to_fpga_manager(d) container_of(d, struct fpga_manager, dev)
+
+int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags,
+		      const char *buf, size_t count);
+
+int fpga_mgr_firmware_load(struct fpga_manager *mgr, u32 flags,
+			   const char *image_name);
+
+struct fpga_manager *of_fpga_mgr_get(struct device_node *node);
+
+void fpga_mgr_put(struct fpga_manager *mgr);
+
+int fpga_mgr_register(struct device *dev, const char *name,
+		      const struct fpga_manager_ops *mops, void *priv);
+
+void fpga_mgr_unregister(struct device *dev);
+
+#endif /*_LINUX_FPGA_MGR_H */