diff options
Diffstat (limited to 'drivers/fpga/fpga-region.c')
| -rw-r--r-- | drivers/fpga/fpga-region.c | 603 |
1 files changed, 603 insertions, 0 deletions
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c new file mode 100644 index 000000000000..3222fdbad75a --- /dev/null +++ b/drivers/fpga/fpga-region.c @@ -0,0 +1,603 @@ +/* + * FPGA Region - Device Tree support for FPGA programming under Linux + * + * Copyright (C) 2013-2016 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/fpga/fpga-bridge.h> +#include <linux/fpga/fpga-mgr.h> +#include <linux/idr.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +/** + * struct fpga_region - FPGA Region structure + * @dev: FPGA Region device + * @mutex: enforces exclusive reference to region + * @bridge_list: list of FPGA bridges specified in region + * @info: fpga image specific information + */ +struct fpga_region { + struct device dev; + struct mutex mutex; /* for exclusive reference to region */ + struct list_head bridge_list; + struct fpga_image_info *info; +}; + +#define to_fpga_region(d) container_of(d, struct fpga_region, dev) + +static DEFINE_IDA(fpga_region_ida); +static struct class *fpga_region_class; + +static const struct of_device_id fpga_region_of_match[] = { + { .compatible = "fpga-region", }, + {}, +}; +MODULE_DEVICE_TABLE(of, fpga_region_of_match); + +static int fpga_region_of_node_match(struct device *dev, const void *data) +{ + return dev->of_node == data; +} + +/** + * fpga_region_find - find FPGA region + * @np: device node of FPGA Region + * Caller will need to put_device(®ion->dev) when done. + * Returns FPGA Region struct or NULL + */ +static struct fpga_region *fpga_region_find(struct device_node *np) +{ + struct device *dev; + + dev = class_find_device(fpga_region_class, NULL, np, + fpga_region_of_node_match); + if (!dev) + return NULL; + + return to_fpga_region(dev); +} + +/** + * fpga_region_get - get an exclusive reference to a fpga region + * @region: FPGA Region struct + * + * Caller should call fpga_region_put() when done with region. + * + * Return fpga_region struct if successful. + * Return -EBUSY if someone already has a reference to the region. + * Return -ENODEV if @np is not a FPGA Region. + */ +static struct fpga_region *fpga_region_get(struct fpga_region *region) +{ + struct device *dev = ®ion->dev; + + if (!mutex_trylock(®ion->mutex)) { + dev_dbg(dev, "%s: FPGA Region already in use\n", __func__); + return ERR_PTR(-EBUSY); + } + + get_device(dev); + of_node_get(dev->of_node); + if (!try_module_get(dev->parent->driver->owner)) { + of_node_put(dev->of_node); + put_device(dev); + mutex_unlock(®ion->mutex); + return ERR_PTR(-ENODEV); + } + + dev_dbg(®ion->dev, "get\n"); + + return region; +} + +/** + * fpga_region_put - release a reference to a region + * + * @region: FPGA region + */ +static void fpga_region_put(struct fpga_region *region) +{ + struct device *dev = ®ion->dev; + + dev_dbg(®ion->dev, "put\n"); + + module_put(dev->parent->driver->owner); + of_node_put(dev->of_node); + put_device(dev); + mutex_unlock(®ion->mutex); +} + +/** + * fpga_region_get_manager - get exclusive reference for FPGA manager + * @region: FPGA region + * + * Get FPGA Manager from "fpga-mgr" property or from ancestor region. + * + * Caller should call fpga_mgr_put() when done with manager. + * + * Return: fpga manager struct or IS_ERR() condition containing error code. + */ +static struct fpga_manager *fpga_region_get_manager(struct fpga_region *region) +{ + struct device *dev = ®ion->dev; + struct device_node *np = dev->of_node; + struct device_node *mgr_node; + struct fpga_manager *mgr; + + of_node_get(np); + while (np) { + if (of_device_is_compatible(np, "fpga-region")) { + mgr_node = of_parse_phandle(np, "fpga-mgr", 0); + if (mgr_node) { + mgr = of_fpga_mgr_get(mgr_node); + of_node_put(np); + return mgr; + } + } + np = of_get_next_parent(np); + } + of_node_put(np); + + return ERR_PTR(-EINVAL); +} + +/** + * fpga_region_get_bridges - create a list of bridges + * @region: FPGA region + * @overlay: device node of the overlay + * + * Create a list of bridges including the parent bridge and the bridges + * specified by "fpga-bridges" property. Note that the + * fpga_bridges_enable/disable/put functions are all fine with an empty list + * if that happens. + * + * Caller should call fpga_bridges_put(®ion->bridge_list) when + * done with the bridges. + * + * Return 0 for success (even if there are no bridges specified) + * or -EBUSY if any of the bridges are in use. + */ +static int fpga_region_get_bridges(struct fpga_region *region, + struct device_node *overlay) +{ + struct device *dev = ®ion->dev; + struct device_node *region_np = dev->of_node; + struct device_node *br, *np, *parent_br = NULL; + int i, ret; + + /* If parent is a bridge, add to list */ + ret = fpga_bridge_get_to_list(region_np->parent, region->info, + ®ion->bridge_list); + if (ret == -EBUSY) + return ret; + + if (!ret) + parent_br = region_np->parent; + + /* If overlay has a list of bridges, use it. */ + if (of_parse_phandle(overlay, "fpga-bridges", 0)) + np = overlay; + else + np = region_np; + + for (i = 0; ; i++) { + br = of_parse_phandle(np, "fpga-bridges", i); + if (!br) + break; + + /* If parent bridge is in list, skip it. */ + if (br == parent_br) + continue; + + /* If node is a bridge, get it and add to list */ + ret = fpga_bridge_get_to_list(br, region->info, + ®ion->bridge_list); + + /* If any of the bridges are in use, give up */ + if (ret == -EBUSY) { + fpga_bridges_put(®ion->bridge_list); + return -EBUSY; + } + } + + return 0; +} + +/** + * fpga_region_program_fpga - program FPGA + * @region: FPGA region + * @firmware_name: name of FPGA image firmware file + * @overlay: device node of the overlay + * Program an FPGA using information in the device tree. + * Function assumes that there is a firmware-name property. + * Return 0 for success or negative error code. + */ +static int fpga_region_program_fpga(struct fpga_region *region, + const char *firmware_name, + struct device_node *overlay) +{ + struct fpga_manager *mgr; + int ret; + + region = fpga_region_get(region); + if (IS_ERR(region)) { + pr_err("failed to get fpga region\n"); + return PTR_ERR(region); + } + + mgr = fpga_region_get_manager(region); + if (IS_ERR(mgr)) { + pr_err("failed to get fpga region manager\n"); + return PTR_ERR(mgr); + } + + ret = fpga_region_get_bridges(region, overlay); + if (ret) { + pr_err("failed to get fpga region bridges\n"); + goto err_put_mgr; + } + + ret = fpga_bridges_disable(®ion->bridge_list); + if (ret) { + pr_err("failed to disable region bridges\n"); + goto err_put_br; + } + + ret = fpga_mgr_firmware_load(mgr, region->info, firmware_name); + if (ret) { + pr_err("failed to load fpga image\n"); + goto err_put_br; + } + + ret = fpga_bridges_enable(®ion->bridge_list); + if (ret) { + pr_err("failed to enable region bridges\n"); + goto err_put_br; + } + + fpga_mgr_put(mgr); + fpga_region_put(region); + + return 0; + +err_put_br: + fpga_bridges_put(®ion->bridge_list); +err_put_mgr: + fpga_mgr_put(mgr); + fpga_region_put(region); + + return ret; +} + +/** + * child_regions_with_firmware + * @overlay: device node of the overlay + * + * If the overlay adds child FPGA regions, they are not allowed to have + * firmware-name property. + * + * Return 0 for OK or -EINVAL if child FPGA region adds firmware-name. + */ +static int child_regions_with_firmware(struct device_node *overlay) +{ + struct device_node *child_region; + const char *child_firmware_name; + int ret = 0; + + of_node_get(overlay); + + child_region = of_find_matching_node(overlay, fpga_region_of_match); + while (child_region) { + if (!of_property_read_string(child_region, "firmware-name", + &child_firmware_name)) { + ret = -EINVAL; + break; + } + child_region = of_find_matching_node(child_region, + fpga_region_of_match); + } + + of_node_put(child_region); + + if (ret) + pr_err("firmware-name not allowed in child FPGA region: %s", + child_region->full_name); + + return ret; +} + +/** + * fpga_region_notify_pre_apply - pre-apply overlay notification + * + * @region: FPGA region that the overlay was applied to + * @nd: overlay notification data + * + * Called after when an overlay targeted to a FPGA Region is about to be + * applied. Function will check the properties that will be added to the FPGA + * region. If the checks pass, it will program the FPGA. + * + * The checks are: + * The overlay must add either firmware-name or external-fpga-config property + * to the FPGA Region. + * + * firmware-name : program the FPGA + * external-fpga-config : FPGA is already programmed + * + * The overlay can add other FPGA regions, but child FPGA regions cannot have a + * firmware-name property since those regions don't exist yet. + * + * If the overlay that breaks the rules, notifier returns an error and the + * overlay is rejected before it goes into the main tree. + * + * Returns 0 for success or negative error code for failure. + */ +static int fpga_region_notify_pre_apply(struct fpga_region *region, + struct of_overlay_notify_data *nd) +{ + const char *firmware_name = NULL; + struct fpga_image_info *info; + int ret; + + info = devm_kzalloc(®ion->dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + region->info = info; + + /* Reject overlay if child FPGA Regions have firmware-name property */ + ret = child_regions_with_firmware(nd->overlay); + if (ret) + return ret; + + /* Read FPGA region properties from the overlay */ + if (of_property_read_bool(nd->overlay, "partial-fpga-config")) + info->flags |= FPGA_MGR_PARTIAL_RECONFIG; + + if (of_property_read_bool(nd->overlay, "external-fpga-config")) + info->flags |= FPGA_MGR_EXTERNAL_CONFIG; + + of_property_read_string(nd->overlay, "firmware-name", &firmware_name); + + of_property_read_u32(nd->overlay, "region-unfreeze-timeout-us", + &info->enable_timeout_us); + + of_property_read_u32(nd->overlay, "region-freeze-timeout-us", + &info->disable_timeout_us); + + /* If FPGA was externally programmed, don't specify firmware */ + if ((info->flags & FPGA_MGR_EXTERNAL_CONFIG) && firmware_name) { + pr_err("error: specified firmware and external-fpga-config"); + return -EINVAL; + } + + /* FPGA is already configured externally. We're done. */ + if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) + return 0; + + /* If we got this far, we should be programming the FPGA */ + if (!firmware_name) { + pr_err("should specify firmware-name or external-fpga-config\n"); + return -EINVAL; + } + + return fpga_region_program_fpga(region, firmware_name, nd->overlay); +} + +/** + * fpga_region_notify_post_remove - post-remove overlay notification + * + * @region: FPGA region that was targeted by the overlay that was removed + * @nd: overlay notification data + * + * Called after an overlay has been removed if the overlay's target was a + * FPGA region. + */ +static void fpga_region_notify_post_remove(struct fpga_region *region, + struct of_overlay_notify_data *nd) +{ + fpga_bridges_disable(®ion->bridge_list); + fpga_bridges_put(®ion->bridge_list); + devm_kfree(®ion->dev, region->info); + region->info = NULL; +} + +/** + * of_fpga_region_notify - reconfig notifier for dynamic DT changes + * @nb: notifier block + * @action: notifier action + * @arg: reconfig data + * + * This notifier handles programming a FPGA when a "firmware-name" property is + * added to a fpga-region. + * + * Returns NOTIFY_OK or error if FPGA programming fails. + */ +static int of_fpga_region_notify(struct notifier_block *nb, + unsigned long action, void *arg) +{ + struct of_overlay_notify_data *nd = arg; + struct fpga_region *region; + int ret; + + switch (action) { + case OF_OVERLAY_PRE_APPLY: + pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__); + break; + case OF_OVERLAY_POST_APPLY: + pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__); + return NOTIFY_OK; /* not for us */ + case OF_OVERLAY_PRE_REMOVE: + pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__); + return NOTIFY_OK; /* not for us */ + case OF_OVERLAY_POST_REMOVE: + pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__); + break; + default: /* should not happen */ + return NOTIFY_OK; + } + + region = fpga_region_find(nd->target); + if (!region) + return NOTIFY_OK; + + ret = 0; + switch (action) { + case OF_OVERLAY_PRE_APPLY: + ret = fpga_region_notify_pre_apply(region, nd); + break; + + case OF_OVERLAY_POST_REMOVE: + fpga_region_notify_post_remove(region, nd); + break; + } + + put_device(®ion->dev); + + if (ret) + return notifier_from_errno(ret); + + return NOTIFY_OK; +} + +static struct notifier_block fpga_region_of_nb = { + .notifier_call = of_fpga_region_notify, +}; + +static int fpga_region_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct fpga_region *region; + int id, ret = 0; + + region = kzalloc(sizeof(*region), GFP_KERNEL); + if (!region) + return -ENOMEM; + + id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL); + if (id < 0) { + ret = id; + goto err_kfree; + } + + mutex_init(®ion->mutex); + INIT_LIST_HEAD(®ion->bridge_list); + + device_initialize(®ion->dev); + region->dev.class = fpga_region_class; + region->dev.parent = dev; + region->dev.of_node = np; + region->dev.id = id; + dev_set_drvdata(dev, region); + + ret = dev_set_name(®ion->dev, "region%d", id); + if (ret) + goto err_remove; + + ret = device_add(®ion->dev); + if (ret) + goto err_remove; + + of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev); + + dev_info(dev, "FPGA Region probed\n"); + + return 0; + +err_remove: + ida_simple_remove(&fpga_region_ida, id); +err_kfree: + kfree(region); + + return ret; +} + +static int fpga_region_remove(struct platform_device *pdev) +{ + struct fpga_region *region = platform_get_drvdata(pdev); + + device_unregister(®ion->dev); + + return 0; +} + +static struct platform_driver fpga_region_driver = { + .probe = fpga_region_probe, + .remove = fpga_region_remove, + .driver = { + .name = "fpga-region", + .of_match_table = of_match_ptr(fpga_region_of_match), + }, +}; + +static void fpga_region_dev_release(struct device *dev) +{ + struct fpga_region *region = to_fpga_region(dev); + + ida_simple_remove(&fpga_region_ida, region->dev.id); + kfree(region); +} + +/** + * fpga_region_init - init function for fpga_region class + * Creates the fpga_region class and registers a reconfig notifier. + */ +static int __init fpga_region_init(void) +{ + int ret; + + fpga_region_class = class_create(THIS_MODULE, "fpga_region"); + if (IS_ERR(fpga_region_class)) + return PTR_ERR(fpga_region_class); + + fpga_region_class->dev_release = fpga_region_dev_release; + + ret = of_overlay_notifier_register(&fpga_region_of_nb); + if (ret) + goto err_class; + + ret = platform_driver_register(&fpga_region_driver); + if (ret) + goto err_plat; + + return 0; + +err_plat: + of_overlay_notifier_unregister(&fpga_region_of_nb); +err_class: + class_destroy(fpga_region_class); + ida_destroy(&fpga_region_ida); + return ret; +} + +static void __exit fpga_region_exit(void) +{ + platform_driver_unregister(&fpga_region_driver); + of_overlay_notifier_unregister(&fpga_region_of_nb); + class_destroy(fpga_region_class); + ida_destroy(&fpga_region_ida); +} + +subsys_initcall(fpga_region_init); +module_exit(fpga_region_exit); + +MODULE_DESCRIPTION("FPGA Region"); +MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>"); +MODULE_LICENSE("GPL v2"); |