diff options
Diffstat (limited to 'drivers/fpga/of-fpga-region.c')
| -rw-r--r-- | drivers/fpga/of-fpga-region.c | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c new file mode 100644 index 000000000..ae82532fc --- /dev/null +++ b/drivers/fpga/of-fpga-region.c @@ -0,0 +1,482 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * FPGA Region - Device Tree support for FPGA programming under Linux + * + * Copyright (C) 2013-2016 Altera Corporation + * Copyright (C) 2017 Intel Corporation + */ +#include <linux/fpga/fpga-bridge.h> +#include <linux/fpga/fpga-mgr.h> +#include <linux/fpga/fpga-region.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> + +static const struct of_device_id fpga_region_of_match[] = { + { .compatible = "fpga-region", }, + {}, +}; +MODULE_DEVICE_TABLE(of, fpga_region_of_match); + +/** + * of_fpga_region_find - find FPGA region + * @np: device node of FPGA Region + * + * Caller will need to put_device(®ion->dev) when done. + * + * Return: FPGA Region struct or NULL + */ +static struct fpga_region *of_fpga_region_find(struct device_node *np) +{ + return fpga_region_class_find(NULL, np, device_match_of_node); +} + +/** + * of_fpga_region_get_mgr - get reference for FPGA manager + * @np: device node of 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 *of_fpga_region_get_mgr(struct device_node *np) +{ + 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(mgr_node); + of_node_put(np); + return mgr; + } + } + np = of_get_next_parent(np); + } + of_node_put(np); + + return ERR_PTR(-EINVAL); +} + +/** + * of_fpga_region_get_bridges - create a list of bridges + * @region: FPGA region + * + * 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 of_fpga_region_get_bridges(struct fpga_region *region) +{ + struct device *dev = ®ion->dev; + struct device_node *region_np = dev->of_node; + struct fpga_image_info *info = region->info; + struct device_node *br, *np, *parent_br = NULL; + int i, ret; + + /* If parent is a bridge, add to list */ + ret = of_fpga_bridge_get_to_list(region_np->parent, info, + ®ion->bridge_list); + + /* -EBUSY means parent is a bridge that is under use. Give up. */ + if (ret == -EBUSY) + return ret; + + /* Zero return code means parent was a bridge and was added to list. */ + if (!ret) + parent_br = region_np->parent; + + /* If overlay has a list of bridges, use it. */ + br = of_parse_phandle(info->overlay, "fpga-bridges", 0); + if (br) { + of_node_put(br); + np = info->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) { + of_node_put(br); + continue; + } + + /* If node is a bridge, get it and add to list */ + ret = of_fpga_bridge_get_to_list(br, info, + ®ion->bridge_list); + of_node_put(br); + + /* If any of the bridges are in use, give up */ + if (ret == -EBUSY) { + fpga_bridges_put(®ion->bridge_list); + return -EBUSY; + } + } + + return 0; +} + +/** + * child_regions_with_firmware - Used to check the child region info. + * @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: %pOF", + child_region); + + return ret; +} + +/** + * of_fpga_region_parse_ov - parse and check overlay applied to region + * + * @region: FPGA region + * @overlay: overlay applied to the FPGA region + * + * Given an overlay applied to an FPGA region, parse the FPGA image specific + * info in the overlay and do some checking. + * + * Return: + * NULL if overlay doesn't direct us to program the FPGA. + * fpga_image_info struct if there is an image to program. + * error code for invalid overlay. + */ +static struct fpga_image_info * +of_fpga_region_parse_ov(struct fpga_region *region, + struct device_node *overlay) +{ + struct device *dev = ®ion->dev; + struct fpga_image_info *info; + const char *firmware_name; + int ret; + + if (region->info) { + dev_err(dev, "Region already has overlay applied.\n"); + return ERR_PTR(-EINVAL); + } + + /* + * Reject overlay if child FPGA Regions added in the overlay have + * firmware-name property (would mean that an FPGA region that has + * not been added to the live tree yet is doing FPGA programming). + */ + ret = child_regions_with_firmware(overlay); + if (ret) + return ERR_PTR(ret); + + info = fpga_image_info_alloc(dev); + if (!info) + return ERR_PTR(-ENOMEM); + + info->overlay = overlay; + + /* Read FPGA region properties from the overlay */ + if (of_property_read_bool(overlay, "partial-fpga-config")) + info->flags |= FPGA_MGR_PARTIAL_RECONFIG; + + if (of_property_read_bool(overlay, "external-fpga-config")) + info->flags |= FPGA_MGR_EXTERNAL_CONFIG; + + if (of_property_read_bool(overlay, "encrypted-fpga-config")) + info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM; + + if (!of_property_read_string(overlay, "firmware-name", + &firmware_name)) { + info->firmware_name = devm_kstrdup(dev, firmware_name, + GFP_KERNEL); + if (!info->firmware_name) + return ERR_PTR(-ENOMEM); + } + + of_property_read_u32(overlay, "region-unfreeze-timeout-us", + &info->enable_timeout_us); + + of_property_read_u32(overlay, "region-freeze-timeout-us", + &info->disable_timeout_us); + + of_property_read_u32(overlay, "config-complete-timeout-us", + &info->config_complete_timeout_us); + + /* If overlay is not programming the FPGA, don't need FPGA image info */ + if (!info->firmware_name) { + ret = 0; + goto ret_no_info; + } + + /* + * If overlay informs us FPGA was externally programmed, specifying + * firmware here would be ambiguous. + */ + if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) { + dev_err(dev, "error: specified firmware and external-fpga-config"); + ret = -EINVAL; + goto ret_no_info; + } + + return info; +ret_no_info: + fpga_image_info_free(info); + return ERR_PTR(ret); +} + +/** + * of_fpga_region_notify_pre_apply - pre-apply overlay notification + * + * @region: FPGA region that the overlay was applied to + * @nd: overlay notification data + * + * Called when an overlay targeted to an FPGA Region is about to be applied. + * Parses the overlay for properties that influence how the FPGA will be + * programmed and does some checking. If the checks pass, programs the FPGA. + * If the checks fail, overlay is rejected and does not get added to the + * live tree. + * + * Return: 0 for success or negative error code for failure. + */ +static int of_fpga_region_notify_pre_apply(struct fpga_region *region, + struct of_overlay_notify_data *nd) +{ + struct device *dev = ®ion->dev; + struct fpga_image_info *info; + int ret; + + info = of_fpga_region_parse_ov(region, nd->overlay); + if (IS_ERR(info)) + return PTR_ERR(info); + + /* If overlay doesn't program the FPGA, accept it anyway. */ + if (!info) + return 0; + + if (region->info) { + dev_err(dev, "Region already has overlay applied.\n"); + return -EINVAL; + } + + region->info = info; + ret = fpga_region_program_fpga(region); + if (ret) { + /* error; reject overlay */ + fpga_image_info_free(info); + region->info = NULL; + } + + return ret; +} + +/** + * of_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 of_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); + fpga_image_info_free(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 an FPGA when a "firmware-name" property is + * added to an fpga-region. + * + * Return: 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 = of_fpga_region_find(nd->target); + if (!region) + return NOTIFY_OK; + + ret = 0; + switch (action) { + case OF_OVERLAY_PRE_APPLY: + ret = of_fpga_region_notify_pre_apply(region, nd); + break; + + case OF_OVERLAY_POST_REMOVE: + of_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 of_fpga_region_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct fpga_region *region; + struct fpga_manager *mgr; + int ret; + + /* Find the FPGA mgr specified by region or parent region. */ + mgr = of_fpga_region_get_mgr(np); + if (IS_ERR(mgr)) + return -EPROBE_DEFER; + + region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges); + if (IS_ERR(region)) { + ret = PTR_ERR(region); + goto eprobe_mgr_put; + } + + of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev); + platform_set_drvdata(pdev, region); + + dev_info(dev, "FPGA Region probed\n"); + + return 0; + +eprobe_mgr_put: + fpga_mgr_put(mgr); + return ret; +} + +static int of_fpga_region_remove(struct platform_device *pdev) +{ + struct fpga_region *region = platform_get_drvdata(pdev); + struct fpga_manager *mgr = region->mgr; + + fpga_region_unregister(region); + fpga_mgr_put(mgr); + + return 0; +} + +static struct platform_driver of_fpga_region_driver = { + .probe = of_fpga_region_probe, + .remove = of_fpga_region_remove, + .driver = { + .name = "of-fpga-region", + .of_match_table = of_match_ptr(fpga_region_of_match), + }, +}; + +/** + * of_fpga_region_init - init function for fpga_region class + * Creates the fpga_region class and registers a reconfig notifier. + * + * Return: 0 on success, negative error code otherwise. + */ +static int __init of_fpga_region_init(void) +{ + int ret; + + ret = of_overlay_notifier_register(&fpga_region_of_nb); + if (ret) + return ret; + + ret = platform_driver_register(&of_fpga_region_driver); + if (ret) + goto err_plat; + + return 0; + +err_plat: + of_overlay_notifier_unregister(&fpga_region_of_nb); + return ret; +} + +static void __exit of_fpga_region_exit(void) +{ + platform_driver_unregister(&of_fpga_region_driver); + of_overlay_notifier_unregister(&fpga_region_of_nb); +} + +subsys_initcall(of_fpga_region_init); +module_exit(of_fpga_region_exit); + +MODULE_DESCRIPTION("FPGA Region"); +MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); +MODULE_LICENSE("GPL v2"); |