add FPGA manager core
[cascardo/linux.git] / drivers / fpga / fpga-mgr.c
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
new file mode 100644 (file)
index 0000000..2526163
--- /dev/null
@@ -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);