Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754923AbaJ1Ugi (ORCPT ); Tue, 28 Oct 2014 16:36:38 -0400 Received: from mail-wg0-f42.google.com ([74.125.82.42]:59958 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754888AbaJ1Ug3 (ORCPT ); Tue, 28 Oct 2014 16:36:29 -0400 From: Pantelis Antoniou To: Grant Likely Cc: Rob Herring , Stephen Warren , Matt Porter , Koen Kooi , Greg Kroah-Hartman , Alison Chaiken , Dinh Nguyen , Jan Lubbe , Alexander Sverdlin , Michael Stickel , Guenter Roeck , Dirk Behme , Alan Tull , Sascha Hauer , Michael Bohan , Ionut Nicu , Michal Simek , Matt Ranostay , Joel Becker , devicetree@vger.kernel.org, Wolfram Sang , linux-i2c@vger.kernel.org, Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Pete Popov , Dan Malek , Georgi Vlaev , Pantelis Antoniou , Pantelis Antoniou Subject: [PATCH v8 3/8] OF: DT-Overlay configfs interface (v2) Date: Tue, 28 Oct 2014 22:36:00 +0200 Message-Id: <1414528565-10907-4-git-send-email-pantelis.antoniou@konsulko.com> X-Mailer: git-send-email 1.7.12 In-Reply-To: <1414528565-10907-1-git-send-email-pantelis.antoniou@konsulko.com> References: <1414528565-10907-1-git-send-email-pantelis.antoniou@konsulko.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a runtime interface to using configfs for generic device tree overlay usage. A device-tree configfs entry is created in /config/device-tree/overlays * To create an overlay you mkdir the directory: # mkdir /config/device-tree/overlays/foo * Either you echo the overlay firmware file to the path property file. # echo foo.dtbo >/config/device-tree/overlays/foo/path * Or you cat the contents of the overlay to the dtbo file # cat foo.dtbo >/config/device-tree/overlays/foo/dtbo The overlay file will be applied. To remove it simply rmdir the directory. # rmdir /config/device-tree/overlays/foo Changes since v1: * of_resolve() -> of_resolve_phandles(). Signed-off-by: Pantelis Antoniou --- drivers/of/Kconfig | 7 ++ drivers/of/Makefile | 1 + drivers/of/configfs.c | 340 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 348 insertions(+) create mode 100644 drivers/of/configfs.c diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index aa315c4..d59ba40 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -90,4 +90,11 @@ config OF_OVERLAY select OF_DEVICE select OF_RESOLVE +config OF_CONFIGFS + bool "OpenFirmware Overlay ConfigFS interface" + select CONFIGFS_FS + select OF_OVERLAY + help + Enable a simple user-space driver DT overlay interface. + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 1bfe462..6d12949 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_OF_MTD) += of_mtd.o obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o obj-$(CONFIG_OF_RESOLVE) += resolver.o obj-$(CONFIG_OF_OVERLAY) += overlay.o +obj-$(CONFIG_OF_CONFIGFS) += configfs.o CFLAGS_fdt.o = -I$(src)/../../scripts/dtc/libfdt CFLAGS_fdt_address.o = -I$(src)/../../scripts/dtc/libfdt diff --git a/drivers/of/configfs.c b/drivers/of/configfs.c new file mode 100644 index 0000000..932f572 --- /dev/null +++ b/drivers/of/configfs.c @@ -0,0 +1,340 @@ +/* + * Configfs entries for device-tree + * + * Copyright (C) 2013 - Pantelis Antoniou + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "of_private.h" + +#ifdef CONFIG_OF_OVERLAY + +struct cfs_overlay_item { + struct config_item item; + + char path[PATH_MAX]; + + const struct firmware *fw; + struct device_node *overlay; + int ov_id; + + void *dtbo; + int dtbo_size; +}; + +static int create_overlay(struct cfs_overlay_item *overlay, void *blob) +{ + int err; + + /* unflatten the tree */ + of_fdt_unflatten_tree((void *)blob, &overlay->overlay); + if (overlay->overlay == NULL) { + pr_err("%s: failed to unflatten tree\n", __func__); + err = -EINVAL; + goto out_err; + } + pr_debug("%s: unflattened OK\n", __func__); + + /* mark it as detached */ + of_node_set_flag(overlay->overlay, OF_DETACHED); + + /* perform resolution */ + err = of_resolve_phandles(overlay->overlay); + if (err != 0) { + pr_err("%s: Failed to resolve tree\n", __func__); + goto out_err; + } + pr_debug("%s: resolved OK\n", __func__); + + err = of_overlay_create(overlay->overlay); + if (err < 0) { + pr_err("%s: Failed to create overlay (err=%d)\n", + __func__, err); + goto out_err; + } + overlay->ov_id = err; + +out_err: + return err; +} + +static inline struct cfs_overlay_item *to_cfs_overlay_item( + struct config_item *item) +{ + return item ? container_of(item, struct cfs_overlay_item, item) : NULL; +} + +CONFIGFS_ATTR_STRUCT(cfs_overlay_item); +#define CFS_OVERLAY_ITEM_ATTR(_name, _mode, _show, _store) \ +struct cfs_overlay_item_attribute cfs_overlay_item_attr_##_name = \ + __CONFIGFS_ATTR(_name, _mode, _show, _store) +#define CFS_OVERLAY_ITEM_ATTR_RO(_name, _show) \ +struct cfs_overlay_item_attribute cfs_overlay_item_attr_##_name = \ + __CONFIGFS_ATTR_RO(_name, _show) + +CONFIGFS_BIN_ATTR_STRUCT(cfs_overlay_item); +#define CFS_OVERLAY_ITEM_BIN_ATTR(_name, _mode, _read, _write, _priv, _max) \ +struct cfs_overlay_item_bin_attribute cfs_overlay_item_bin_attr_##_name = \ + __CONFIGFS_BIN_ATTR(_name, _mode, _read, _write, _priv, _max) +#define CFS_OVERLAY_ITEM_BIN_ATTR_RO(_name, _read, _priv, _max) \ +struct cfs_overlay_item_bin_attribute cfs_overlay_item_bin_attr_##_name = \ + __CONFIGFS_BIN_ATTR_RO(_name, _read, _priv, _max) + +static ssize_t cfs_overlay_item_path_show(struct cfs_overlay_item *overlay, + char *page) +{ + return sprintf(page, "%s\n", overlay->path); +} + +static ssize_t cfs_overlay_item_path_store(struct cfs_overlay_item *overlay, + const char *page, size_t count) +{ + const char *p = page; + char *s; + int err; + + /* if it's set do not allow changes */ + if (overlay->path[0] != '\0' || overlay->dtbo_size > 0) + return -EPERM; + + /* copy to path buffer (and make sure it's always zero terminated */ + count = snprintf(overlay->path, sizeof(overlay->path) - 1, "%s", p); + overlay->path[sizeof(overlay->path) - 1] = '\0'; + + /* strip trailing newlines */ + s = overlay->path + strlen(overlay->path); + while (s > overlay->path && *--s == '\n') + *s = '\0'; + + pr_debug("%s: path is '%s'\n", __func__, overlay->path); + + err = request_firmware(&overlay->fw, overlay->path, NULL); + if (err != 0) + goto out_err; + + err = create_overlay(overlay, (void *)overlay->fw->data); + if (err != 0) + goto out_err; + + return count; + +out_err: + + release_firmware(overlay->fw); + overlay->fw = NULL; + + overlay->path[0] = '\0'; + return err; +} + +static ssize_t cfs_overlay_item_status_show(struct cfs_overlay_item *overlay, + char *page) +{ + return sprintf(page, "%s\n", + overlay->ov_id >= 0 ? "applied" : "unapplied"); +} + +CFS_OVERLAY_ITEM_ATTR(path, S_IRUGO | S_IWUSR, + cfs_overlay_item_path_show, cfs_overlay_item_path_store); +CFS_OVERLAY_ITEM_ATTR_RO(status, cfs_overlay_item_status_show); + +static struct configfs_attribute *cfs_overlay_attrs[] = { + &cfs_overlay_item_attr_path.attr, + &cfs_overlay_item_attr_status.attr, + NULL, +}; + +ssize_t cfs_overlay_item_dtbo_read(struct cfs_overlay_item *overlay, + void *buf, size_t max_count) +{ + pr_debug("%s: buf=%p max_count=%u\n", __func__, + buf, max_count); + + if (overlay->dtbo == NULL) + return 0; + + /* copy if buffer provided */ + if (buf != NULL) { + /* the buffer must be large enough */ + if (overlay->dtbo_size > max_count) + return -ENOSPC; + + memcpy(buf, overlay->dtbo, overlay->dtbo_size); + } + + return overlay->dtbo_size; +} + +ssize_t cfs_overlay_item_dtbo_write(struct cfs_overlay_item *overlay, + const void *buf, size_t count) +{ + int err; + + /* if it's set do not allow changes */ + if (overlay->path[0] != '\0' || overlay->dtbo_size > 0) + return -EPERM; + + /* copy the contents */ + overlay->dtbo = kmemdup(buf, count, GFP_KERNEL); + if (overlay->dtbo == NULL) + return -ENOMEM; + + overlay->dtbo_size = count; + + err = create_overlay(overlay, overlay->dtbo); + if (err != 0) + goto out_err; + + return count; + +out_err: + kfree(overlay->dtbo); + overlay->dtbo = NULL; + overlay->dtbo_size = 0; + + return err; +} + +CFS_OVERLAY_ITEM_BIN_ATTR(dtbo, S_IRUGO | S_IWUSR, + cfs_overlay_item_dtbo_read, cfs_overlay_item_dtbo_write, + NULL, SZ_1M); + +static struct configfs_bin_attribute *cfs_overlay_bin_attrs[] = { + &cfs_overlay_item_bin_attr_dtbo.bin_attr, + NULL, +}; + +static void cfs_overlay_release(struct config_item *item) +{ + struct cfs_overlay_item *overlay = to_cfs_overlay_item(item); + + if (overlay->ov_id >= 0) + of_overlay_destroy(overlay->ov_id); + if (overlay->fw) + release_firmware(overlay->fw); + /* kfree with NULL is safe */ + kfree(overlay->dtbo); + kfree(overlay); +} + +CONFIGFS_ATTR_OPS(cfs_overlay_item); +CONFIGFS_BIN_ATTR_OPS(cfs_overlay_item); +static struct configfs_item_operations cfs_overlay_item_ops = { + .release = cfs_overlay_release, + .show_attribute = cfs_overlay_item_attr_show, + .store_attribute = cfs_overlay_item_attr_store, + .read_bin_attribute = cfs_overlay_item_bin_attr_read, + .write_bin_attribute = cfs_overlay_item_bin_attr_write, +}; + +static struct config_item_type cfs_overlay_type = { + .ct_item_ops = &cfs_overlay_item_ops, + .ct_attrs = cfs_overlay_attrs, + .ct_bin_attrs = cfs_overlay_bin_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct config_item *cfs_overlay_group_make_item( + struct config_group *group, const char *name) +{ + struct cfs_overlay_item *overlay; + + overlay = kzalloc(sizeof(*overlay), GFP_KERNEL); + if (!overlay) + return ERR_PTR(-ENOMEM); + overlay->ov_id = -1; + + config_item_init_type_name(&overlay->item, name, &cfs_overlay_type); + return &overlay->item; +} + +static void cfs_overlay_group_drop_item(struct config_group *group, + struct config_item *item) +{ + struct cfs_overlay_item *overlay = to_cfs_overlay_item(item); + + config_item_put(&overlay->item); +} + +static struct configfs_group_operations overlays_ops = { + .make_item = cfs_overlay_group_make_item, + .drop_item = cfs_overlay_group_drop_item, +}; + +static struct config_item_type overlays_type = { + .ct_group_ops = &overlays_ops, + .ct_owner = THIS_MODULE, +}; + +#endif /* CONFIG_OF_OVERLAY */ + +static struct configfs_group_operations of_cfs_ops = { + /* empty - we don't allow anything to be created */ +}; + +static struct config_item_type of_cfs_type = { + .ct_group_ops = &of_cfs_ops, + .ct_owner = THIS_MODULE, +}; + +struct config_group of_cfs_overlay_group; + +struct config_group *of_cfs_def_groups[] = { +#ifdef CONFIG_OF_OVERLAY + &of_cfs_overlay_group, +#endif + NULL +}; + +static struct configfs_subsystem of_cfs_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "device-tree", + .ci_type = &of_cfs_type, + }, + .default_groups = of_cfs_def_groups, + }, + .su_mutex = __MUTEX_INITIALIZER(of_cfs_subsys.su_mutex), +}; + +static int __init of_cfs_init(void) +{ + int ret; + + pr_info("%s\n", __func__); + + config_group_init(&of_cfs_subsys.su_group); +#ifdef CONFIG_OF_OVERLAY + config_group_init_type_name(&of_cfs_overlay_group, "overlays", + &overlays_type); +#endif + + ret = configfs_register_subsystem(&of_cfs_subsys); + if (ret != 0) { + pr_err("%s: failed to register subsys\n", __func__); + goto out; + } + pr_info("%s: OK\n", __func__); +out: + return ret; +} +late_initcall(of_cfs_init); -- 1.7.12 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/