diff options
-rw-r--r-- | Documentation/devicetree/overlay-notes.txt | 133 | ||||
-rw-r--r-- | drivers/base/platform.c | 1 | ||||
-rw-r--r-- | drivers/of/Kconfig | 7 | ||||
-rw-r--r-- | drivers/of/Makefile | 1 | ||||
-rw-r--r-- | drivers/of/dynamic.c | 50 | ||||
-rw-r--r-- | drivers/of/of_private.h | 2 | ||||
-rw-r--r-- | drivers/of/overlay.c | 552 | ||||
-rw-r--r-- | drivers/of/platform.c | 129 | ||||
-rw-r--r-- | drivers/of/selftest.c | 6 | ||||
-rw-r--r-- | include/linux/of.h | 39 | ||||
-rw-r--r-- | include/linux/of_platform.h | 10 |
11 files changed, 903 insertions, 27 deletions
diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt new file mode 100644 index 000000000000..30ae758e3eef --- /dev/null +++ b/Documentation/devicetree/overlay-notes.txt @@ -0,0 +1,133 @@ +Device Tree Overlay Notes +------------------------- + +This document describes the implementation of the in-kernel +device tree overlay functionality residing in drivers/of/overlay.c and is a +companion document to Documentation/devicetree/dt-object-internal.txt[1] & +Documentation/devicetree/dynamic-resolution-notes.txt[2] + +How overlays work +----------------- + +A Device Tree's overlay purpose is to modify the kernel's live tree, and +have the modification affecting the state of the the kernel in a way that +is reflecting the changes. +Since the kernel mainly deals with devices, any new device node that result +in an active device should have it created while if the device node is either +disabled or removed all together, the affected device should be deregistered. + +Lets take an example where we have a foo board with the following base tree +which is taken from [1]. + +---- foo.dts ----------------------------------------------------------------- + /* FOO platform */ + / { + compatible = "corp,foo"; + + /* shared resources */ + res: res { + }; + + /* On chip peripherals */ + ocp: ocp { + /* peripherals that are always instantiated */ + peripheral1 { ... }; + } + }; +---- foo.dts ----------------------------------------------------------------- + +The overlay bar.dts, when loaded (and resolved as described in [2]) should + +---- bar.dts ----------------------------------------------------------------- +/plugin/; /* allow undefined label references and record them */ +/ { + .... /* various properties for loader use; i.e. part id etc. */ + fragment@0 { + target = <&ocp>; + __overlay__ { + /* bar peripheral */ + bar { + compatible = "corp,bar"; + ... /* various properties and child nodes */ + } + }; + }; +}; +---- bar.dts ----------------------------------------------------------------- + +result in foo+bar.dts + +---- foo+bar.dts ------------------------------------------------------------- + /* FOO platform + bar peripheral */ + / { + compatible = "corp,foo"; + + /* shared resources */ + res: res { + }; + + /* On chip peripherals */ + ocp: ocp { + /* peripherals that are always instantiated */ + peripheral1 { ... }; + + /* bar peripheral */ + bar { + compatible = "corp,bar"; + ... /* various properties and child nodes */ + } + } + }; +---- foo+bar.dts ------------------------------------------------------------- + +As a result of the the overlay, a new device node (bar) has been created +so a bar platform device will be registered and if a matching device driver +is loaded the device will be created as expected. + +Overlay in-kernel API +-------------------------------- + +The API is quite easy to use. + +1. Call of_overlay_create() to create and apply an overlay. The return value +is a cookie identifying this overlay. + +2. Call of_overlay_destroy() to remove and cleanup the overlay previously +created via the call to of_overlay_create(). Removal of an overlay that +is stacked by another will not be permitted. + +Finally, if you need to remove all overlays in one-go, just call +of_overlay_destroy_all() which will remove every single one in the correct +order. + +Overlay DTS Format +------------------ + +The DTS of an overlay should have the following format: + +{ + /* ignored properties by the overlay */ + + fragment@0 { /* first child node */ + + target=<phandle>; /* phandle target of the overlay */ + or + target-path="/path"; /* target path of the overlay */ + + __overlay__ { + property-a; /* add property-a to the target */ + node-a { /* add to an existing, or create a node-a */ + ... + }; + }; + } + fragment@1 { /* second child node */ + ... + }; + /* more fragments follow */ +} + +Using the non-phandle based target method allows one to use a base DT which does +not contain a __symbols__ node, i.e. it was not compiled with the -@ option. +The __symbols__ node is only required for the target=<phandle> method, since it +contains the information required to map from a phandle to a tree location. diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9eda84246ffd..2fb6e9888f36 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -913,6 +913,7 @@ int __init platform_bus_init(void) error = bus_register(&platform_bus_type); if (error) device_unregister(&platform_bus); + of_platform_register_reconfig_notifier(); return error; } diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index b51ebc38fd7e..e8c2292c4d89 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -85,4 +85,11 @@ config OF_RESERVED_MEM config OF_RESOLVE bool +config OF_OVERLAY + bool + depends on OF + select OF_DYNAMIC + select OF_DEVICE + select OF_RESOLVE + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index c1933a40f6b3..3a426bb402f3 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -14,5 +14,6 @@ obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o obj-$(CONFIG_OF_MTD) += of_mtd.o obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o obj-$(CONFIG_OF_RESOLVE) += resolver.o +obj-$(CONFIG_OF_OVERLAY) += overlay.o CFLAGS_fdt.o = -I$(src)/../../scripts/dtc/libfdt diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index bf3e53e243a1..16524c8e95ec 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -404,36 +404,54 @@ struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags) } /** - * __of_node_alloc() - Create an empty device node dynamically. - * @full_name: Full name of the new device node - * @allocflags: Allocation flags (typically pass GFP_KERNEL) + * __of_node_dup() - Duplicate or create an empty device node dynamically. + * @fmt: Format string (plus vargs) for new full name of the device node * - * Create an empty device tree node, suitable for further modification. - * The node data are dynamically allocated and all the node flags - * have the OF_DYNAMIC & OF_DETACHED bits set. - * Returns the newly allocated node or NULL on out of memory error. + * Create an device tree node, either by duplicating an empty node or by allocating + * an empty one suitable for further modification. The node data are + * dynamically allocated and all the node flags have the OF_DYNAMIC & + * OF_DETACHED bits set. Returns the newly allocated node or NULL on out of + * memory error. */ -struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags) +struct device_node *__of_node_dup(const struct device_node *np, const char *fmt, ...) { + va_list vargs; struct device_node *node; - node = kzalloc(sizeof(*node), allocflags); + node = kzalloc(sizeof(*node), GFP_KERNEL); if (!node) return NULL; + va_start(vargs, fmt); + node->full_name = kvasprintf(GFP_KERNEL, fmt, vargs); + va_end(vargs); + if (!node->full_name) { + kfree(node); + return NULL; + } - node->full_name = kstrdup(full_name, allocflags); of_node_set_flag(node, OF_DYNAMIC); of_node_set_flag(node, OF_DETACHED); - if (!node->full_name) - goto err_free; - of_node_init(node); + /* Iterate over and duplicate all properties */ + if (np) { + struct property *pp, *new_pp; + for_each_property_of_node(np, pp) { + new_pp = __of_prop_dup(pp, GFP_KERNEL); + if (!new_pp) + goto err_prop; + if (__of_add_property(node, new_pp)) { + kfree(new_pp->name); + kfree(new_pp->value); + kfree(new_pp); + goto err_prop; + } + } + } return node; - err_free: - kfree(node->full_name); - kfree(node); + err_prop: + of_node_put(node); /* Frees the node and properties */ return NULL; } diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 858e0a5d9a11..8e882e706cd8 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -61,7 +61,7 @@ static inline int of_property_notify(int action, struct device_node *np, * own the devtree lock or work on detached trees only. */ struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags); -struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags); +__printf(2, 3) struct device_node *__of_node_dup(const struct device_node *np, const char *fmt, ...); extern const void *__of_get_property(const struct device_node *np, const char *name, int *lenp); diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c new file mode 100644 index 000000000000..406664801cb5 --- /dev/null +++ b/drivers/of/overlay.c @@ -0,0 +1,552 @@ +/* + * Functions for working with device tree overlays + * + * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> + * Copyright (C) 2012 Texas Instruments Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + */ +#undef DEBUG +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/idr.h> + +#include "of_private.h" + +/** + * struct of_overlay_info - Holds a single overlay info + * @target: target of the overlay operation + * @overlay: pointer to the overlay contents node + * + * Holds a single overlay state, including all the overlay logs & + * records. + */ +struct of_overlay_info { + struct device_node *target; + struct device_node *overlay; +}; + +/** + * struct of_overlay - Holds a complete overlay transaction + * @node: List on which we are located + * @count: Count of ovinfo structures + * @ovinfo_tab: Overlay info table (count sized) + * @cset: Changeset to be used + * + * Holds a complete overlay transaction + */ +struct of_overlay { + int id; + struct list_head node; + int count; + struct of_overlay_info *ovinfo_tab; + struct of_changeset cset; +}; + +static int of_overlay_apply_one(struct of_overlay *ov, + struct device_node *target, const struct device_node *overlay); + +static int of_overlay_apply_single_property(struct of_overlay *ov, + struct device_node *target, struct property *prop) +{ + struct property *propn, *tprop; + + /* NOTE: Multiple changes of single properties not supported */ + tprop = of_find_property(target, prop->name, NULL); + + /* special properties are not meant to be updated (silent NOP) */ + if (of_prop_cmp(prop->name, "name") == 0 || + of_prop_cmp(prop->name, "phandle") == 0 || + of_prop_cmp(prop->name, "linux,phandle") == 0) + return 0; + + propn = __of_prop_dup(prop, GFP_KERNEL); + if (propn == NULL) + return -ENOMEM; + + /* not found? add */ + if (tprop == NULL) + return of_changeset_add_property(&ov->cset, target, propn); + + /* found? update */ + return of_changeset_update_property(&ov->cset, target, propn); +} + +static int of_overlay_apply_single_device_node(struct of_overlay *ov, + struct device_node *target, struct device_node *child) +{ + const char *cname; + struct device_node *tchild, *grandchild; + int ret = 0; + + cname = kbasename(child->full_name); + if (cname == NULL) + return -ENOMEM; + + /* NOTE: Multiple mods of created nodes not supported */ + tchild = of_get_child_by_name(target, cname); + if (tchild != NULL) { + /* apply overlay recursively */ + ret = of_overlay_apply_one(ov, tchild, child); + of_node_put(tchild); + } else { + /* create empty tree as a target */ + tchild = __of_node_dup(child, "%s/%s", target->full_name, cname); + if (!tchild) + return -ENOMEM; + + /* point to parent */ + tchild->parent = target; + + ret = of_changeset_attach_node(&ov->cset, tchild); + if (ret) + return ret; + + ret = of_overlay_apply_one(ov, tchild, child); + if (ret) + return ret; + } + + return ret; +} + +/* + * Apply a single overlay node recursively. + * + * Note that the in case of an error the target node is left + * in a inconsistent state. Error recovery should be performed + * by using the changeset. + */ +static int of_overlay_apply_one(struct of_overlay *ov, + struct device_node *target, const struct device_node *overlay) +{ + struct device_node *child; + struct property *prop; + int ret; + + for_each_property_of_node(overlay, prop) { + ret = of_overlay_apply_single_property(ov, target, prop); + if (ret) { + pr_err("%s: Failed to apply prop @%s/%s\n", + __func__, target->full_name, prop->name); + return ret; + } + } + + for_each_child_of_node(overlay, child) { + ret = of_overlay_apply_single_device_node(ov, target, child); + if (ret != 0) { + pr_err("%s: Failed to apply single node @%s/%s\n", + __func__, target->full_name, + child->name); + return ret; + } + } + + return 0; +} + +/** + * of_overlay_apply() - Apply @count overlays pointed at by @ovinfo_tab + * @ov: Overlay to apply + * + * Applies the overlays given, while handling all error conditions + * appropriately. Either the operation succeeds, or if it fails the + * live tree is reverted to the state before the attempt. + * Returns 0, or an error if the overlay attempt failed. + */ +static int of_overlay_apply(struct of_overlay *ov) +{ + int i, err; + + /* first we apply the overlays atomically */ + for (i = 0; i < ov->count; i++) { + struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; + + err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay); + if (err != 0) { + pr_err("%s: overlay failed '%s'\n", + __func__, ovinfo->target->full_name); + return err; + } + } + + return 0; +} + +/* + * Find the target node using a number of different strategies + * in order of preference + * + * "target" property containing the phandle of the target + * "target-path" property containing the path of the target + */ +static struct device_node *find_target_node(struct device_node *info_node) +{ + const char *path; + u32 val; + int ret; + + /* first try to go by using the target as a phandle */ + ret = of_property_read_u32(info_node, "target", &val); + if (ret == 0) + return of_find_node_by_phandle(val); + + /* now try to locate by path */ + ret = of_property_read_string(info_node, "target-path", &path); + if (ret == 0) + return of_find_node_by_path(path); + + pr_err("%s: Failed to find target for node %p (%s)\n", __func__, + info_node, info_node->name); + + return NULL; +} + +/** + * of_fill_overlay_info() - Fill an overlay info structure + * @ov Overlay to fill + * @info_node: Device node containing the overlay + * @ovinfo: Pointer to the overlay info structure to fill + * + * Fills an overlay info structure with the overlay information + * from a device node. This device node must have a target property + * which contains a phandle of the overlay target node, and an + * __overlay__ child node which has the overlay contents. + * Both ovinfo->target & ovinfo->overlay have their references taken. + * + * Returns 0 on success, or a negative error value. + */ +static int of_fill_overlay_info(struct of_overlay *ov, + struct device_node *info_node, struct of_overlay_info *ovinfo) +{ + ovinfo->overlay = of_get_child_by_name(info_node, "__overlay__"); + if (ovinfo->overlay == NULL) + goto err_fail; + + ovinfo->target = find_target_node(info_node); + if (ovinfo->target == NULL) + goto err_fail; + + return 0; + +err_fail: + of_node_put(ovinfo->target); + of_node_put(ovinfo->overlay); + + memset(ovinfo, 0, sizeof(*ovinfo)); + return -EINVAL; +} + +/** + * of_build_overlay_info() - Build an overlay info array + * @ov Overlay to build + * @tree: Device node containing all the overlays + * + * Helper function that given a tree containing overlay information, + * allocates and builds an overlay info array containing it, ready + * for use using of_overlay_apply. + * + * Returns 0 on success with the @cntp @ovinfop pointers valid, + * while on error a negative error value is returned. + */ +static int of_build_overlay_info(struct of_overlay *ov, + struct device_node *tree) +{ + struct device_node *node; + struct of_overlay_info *ovinfo; + int cnt, err; + + /* worst case; every child is a node */ + cnt = 0; + for_each_child_of_node(tree, node) + cnt++; + + ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL); + if (ovinfo == NULL) + return -ENOMEM; + + cnt = 0; + for_each_child_of_node(tree, node) { + memset(&ovinfo[cnt], 0, sizeof(*ovinfo)); + err = of_fill_overlay_info(ov, node, &ovinfo[cnt]); + if (err == 0) + cnt++; + } + + /* if nothing filled, return error */ + if (cnt == 0) { + kfree(ovinfo); + return -ENODEV; + } + + ov->count = cnt; + ov->ovinfo_tab = ovinfo; + + return 0; +} + +/** + * of_free_overlay_info() - Free an overlay info array + * @ov Overlay to free the overlay info from + * @ovinfo_tab: Array of overlay_info's to free + * + * Releases the memory of a previously allocated ovinfo array + * by of_build_overlay_info. + * Returns 0, or an error if the arguments are bogus. + */ +static int of_free_overlay_info(struct of_overlay *ov) +{ + struct of_overlay_info *ovinfo; + int i; + + /* do it in reverse */ + for (i = ov->count - 1; i >= 0; i--) { + ovinfo = &ov->ovinfo_tab[i]; + + of_node_put(ovinfo->target); + of_node_put(ovinfo->overlay); + } + kfree(ov->ovinfo_tab); + + return 0; +} + +static LIST_HEAD(ov_list); +static DEFINE_IDR(ov_idr); + +/** + * of_overlay_create() - Create and apply an overlay + * @tree: Device node containing all the overlays + * + * Creates and applies an overlay while also keeping track + * of the overlay in a list. This list can be used to prevent + * illegal overlay removals. + * + * Returns the id of the created overlay, or an negative error number + */ +int of_overlay_create(struct device_node *tree) +{ + struct of_overlay *ov; + int err, id; + + /* allocate the overlay structure */ + ov = kzalloc(sizeof(*ov), GFP_KERNEL); + if (ov == NULL) + return -ENOMEM; + ov->id = -1; + + INIT_LIST_HEAD(&ov->node); + + of_changeset_init(&ov->cset); + + mutex_lock(&of_mutex); + + id = idr_alloc(&ov_idr, ov, 0, 0, GFP_KERNEL); + if (id < 0) { + pr_err("%s: idr_alloc() failed for tree@%s\n", + __func__, tree->full_name); + err = id; + goto err_destroy_trans; + } + ov->id = id; + + /* build the overlay info structures */ + err = of_build_overlay_info(ov, tree); + if (err) { + pr_err("%s: of_build_overlay_info() failed for tree@%s\n", + __func__, tree->full_name); + goto err_free_idr; + } + + /* apply the overlay */ + err = of_overlay_apply(ov); + if (err) { + pr_err("%s: of_overlay_apply() failed for tree@%s\n", + __func__, tree->full_name); + goto err_abort_trans; + } + + /* apply the changeset */ + err = of_changeset_apply(&ov->cset); + if (err) { + pr_err("%s: of_changeset_apply() failed for tree@%s\n", + __func__, tree->full_name); + goto err_revert_overlay; + } + + /* add to the tail of the overlay list */ + list_add_tail(&ov->node, &ov_list); + + mutex_unlock(&of_mutex); + + return id; + +err_revert_overlay: +err_abort_trans: + of_free_overlay_info(ov); +err_free_idr: + idr_remove(&ov_idr, ov->id); +err_destroy_trans: + of_changeset_destroy(&ov->cset); + kfree(ov); + mutex_unlock(&of_mutex); + + return err; +} +EXPORT_SYMBOL_GPL(of_overlay_create); + +/* check whether the given node, lies under the given tree */ +static int overlay_subtree_check(struct device_node *tree, + struct device_node *dn) +{ + struct device_node *child; + + /* match? */ + if (tree == dn) + return 1; + + for_each_child_of_node(tree, child) { + if (overlay_subtree_check(child, dn)) + return 1; + } + + return 0; +} + +/* check whether this overlay is the topmost */ +static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) +{ + struct of_overlay *ovt; + struct of_changeset_entry *ce; + + list_for_each_entry_reverse(ovt, &ov_list, node) { + /* if we hit ourselves, we're done */ + if (ovt == ov) + break; + + /* check against each subtree affected by this overlay */ + list_for_each_entry(ce, &ovt->cset.entries, node) { + if (overlay_subtree_check(ce->np, dn)) { + pr_err("%s: #%d clashes #%d @%s\n", + __func__, ov->id, ovt->id, + dn->full_name); + return 0; + } + } + } + + /* overlay is topmost */ + return 1; +} + +/* + * We can safely remove the overlay only if it's the top-most one. + * Newly applied overlays are inserted at the tail of the overlay list, + * so a top most overlay is the one that is closest to the tail. + * + * The topmost check is done by exploiting this property. For each + * affected device node in the log list we check if this overlay is + * the one closest to the tail. If another overlay has affected this + * device node and is closest to the tail, then removal is not permited. + */ +static int overlay_removal_is_ok(struct of_overlay *ov) +{ + struct of_changeset_entry *ce; + + list_for_each_entry(ce, &ov->cset.entries, node) { + if (!overlay_is_topmost(ov, ce->np)) { + pr_err("%s: overlay #%d is not topmost\n", + __func__, ov->id); + return 0; + } + } + + return 1; +} + +/** + * of_overlay_destroy() - Removes an overlay + * @id: Overlay id number returned by a previous call to of_overlay_create + * + * Removes an overlay if it is permissible. + * + * Returns 0 on success, or an negative error number + */ +int of_overlay_destroy(int id) +{ + struct of_overlay *ov; + int err; + + mutex_lock(&of_mutex); + + ov = idr_find(&ov_idr, id); + if (ov == NULL) { + err = -ENODEV; + pr_err("%s: Could not find overlay #%d\n", + __func__, id); + goto out; + } + + /* check whether the overlay is safe to remove */ + if (!overlay_removal_is_ok(ov)) { + err = -EBUSY; + pr_err("%s: removal check failed for overlay #%d\n", + __func__, id); + goto out; + } + + + list_del(&ov->node); + of_changeset_revert(&ov->cset); + of_free_overlay_info(ov); + idr_remove(&ov_idr, id); + of_changeset_destroy(&ov->cset); + kfree(ov); + + err = 0; + +out: + mutex_unlock(&of_mutex); + + return err; +} +EXPORT_SYMBOL_GPL(of_overlay_destroy); + +/** + * of_overlay_destroy_all() - Removes all overlays from the system + * + * Removes all overlays from the system in the correct order. + * + * Returns 0 on success, or an negative error number + */ +int of_overlay_destroy_all(void) +{ + struct of_overlay *ov, *ovn; + + mutex_lock(&of_mutex); + + /* the tail of list is guaranteed to be safe to remove */ + list_for_each_entry_safe_reverse(ov, ovn, &ov_list, node) { + list_del(&ov->node); + of_changeset_revert(&ov->cset); + of_free_overlay_info(ov); + idr_remove(&ov_idr, ov->id); + kfree(ov); + } + + mutex_unlock(&of_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(of_overlay_destroy_all); diff --git a/drivers/of/platform.c b/drivers/of/platform.c index e0a6514ab46c..41bff21a0829 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -204,12 +204,13 @@ struct platform_device *of_platform_device_create_pdata( { struct platform_device *dev; - if (!of_device_is_available(np)) + if (!of_device_is_available(np) || + of_node_test_and_set_flag(np, OF_POPULATED)) return NULL; dev = of_device_alloc(np, bus_id, parent); if (!dev) - return NULL; + goto err_clear_flag; #if defined(CONFIG_MICROBLAZE) dev->archdata.dma_mask = 0xffffffffUL; @@ -225,10 +226,14 @@ struct platform_device *of_platform_device_create_pdata( if (of_device_add(dev) != 0) { platform_device_put(dev); - return NULL; + goto err_clear_flag; } return dev; + +err_clear_flag: + of_node_clear_flag(np, OF_POPULATED); + return NULL; } /** @@ -260,12 +265,16 @@ static struct amba_device *of_amba_device_create(struct device_node *node, pr_debug("Creating amba device %s\n", node->full_name); - if (!of_device_is_available(node)) + if (!of_device_is_available(node) || + of_node_test_and_set_flag(node, OF_POPULATED)) return NULL; dev = amba_device_alloc(NULL, 0, 0); - if (!dev) - return NULL; + if (!dev) { + pr_err("%s(): amba_device_alloc() failed for %s\n", + __func__, node->full_name); + goto err_clear_flag; + } /* setup generic device info */ dev->dev.coherent_dma_mask = ~0; @@ -301,6 +310,8 @@ static struct amba_device *of_amba_device_create(struct device_node *node, err_free: amba_device_put(dev); +err_clear_flag: + of_node_clear_flag(node, OF_POPULATED); return NULL; } #else /* CONFIG_ARM_AMBA */ @@ -390,6 +401,7 @@ static int of_platform_bus_create(struct device_node *bus, break; } } + of_node_set_flag(bus, OF_POPULATED_BUS); return rc; } @@ -473,4 +485,109 @@ int of_platform_populate(struct device_node *root, return rc; } EXPORT_SYMBOL_GPL(of_platform_populate); + +static int of_platform_device_destroy(struct device *dev, void *data) +{ + /* Do not touch devices not populated from the device tree */ + if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) + return 0; + + /* Recurse for any nodes that were treated as busses */ + if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS)) + device_for_each_child(dev, NULL, of_platform_device_destroy); + + if (dev->bus == &platform_bus_type) + platform_device_unregister(to_platform_device(dev)); +#ifdef CONFIG_ARM_AMBA + else if (dev->bus == &amba_bustype) + amba_device_unregister(to_amba_device(dev)); +#endif + + of_node_clear_flag(dev->of_node, OF_POPULATED); + of_node_clear_flag(dev->of_node, OF_POPULATED_BUS); + return 0; +} + +/** + * of_platform_depopulate() - Remove devices populated from device tree + * @parent: device which children will be removed + * + * Complementary to of_platform_populate(), this function removes children + * of the given device (and, recurrently, their children) that have been + * created from their respective device tree nodes (and only those, + * leaving others - eg. manually created - unharmed). + * + * Returns 0 when all children devices have been removed or + * -EBUSY when some children remained. + */ +void of_platform_depopulate(struct device *parent) +{ + device_for_each_child(parent, NULL, of_platform_device_destroy); +} +EXPORT_SYMBOL_GPL(of_platform_depopulate); + +#ifdef CONFIG_OF_DYNAMIC +static int of_platform_notify(struct notifier_block *nb, + unsigned long action, void *arg) +{ + struct of_reconfig_data *rd = arg; + struct platform_device *pdev_parent, *pdev; + bool children_left; + + switch (of_reconfig_get_state_change(action, rd)) { + case OF_RECONFIG_CHANGE_ADD: + /* verify that the parent is a bus */ + if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS)) + return NOTIFY_OK; /* not for us */ + + /* already populated? (driver using of_populate manually) */ + if (of_node_check_flag(rd->dn, OF_POPULATED)) + return NOTIFY_OK; + + /* pdev_parent may be NULL when no bus platform device */ + pdev_parent = of_find_device_by_node(rd->dn->parent); + pdev = of_platform_device_create(rd->dn, NULL, + pdev_parent ? &pdev_parent->dev : NULL); + of_dev_put(pdev_parent); + + if (pdev == NULL) { + pr_err("%s: failed to create for '%s'\n", + __func__, rd->dn->full_name); + /* of_platform_device_create tosses the error code */ + return notifier_from_errno(-EINVAL); + } + break; + + case OF_RECONFIG_CHANGE_REMOVE: + + /* already depopulated? */ + if (!of_node_check_flag(rd->dn, OF_POPULATED)) + return NOTIFY_OK; + + /* find our device by node */ + pdev = of_find_device_by_node(rd->dn); + if (pdev == NULL) + return NOTIFY_OK; /* no? not meant for us */ + + /* unregister takes one ref away */ + of_platform_device_destroy(&pdev->dev, &children_left); + + /* and put the reference of the find */ + of_dev_put(pdev); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block platform_of_notifier = { + .notifier_call = of_platform_notify, +}; + +void of_platform_register_reconfig_notifier(void) +{ + WARN_ON(of_reconfig_notifier_register(&platform_of_notifier)); +} +#endif /* CONFIG_OF_DYNAMIC */ + #endif /* CONFIG_OF_ADDRESS */ diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c index 825d89cbfde2..37f57ad3bdbf 100644 --- a/drivers/of/selftest.c +++ b/drivers/of/selftest.c @@ -249,11 +249,11 @@ static void __init of_selftest_changeset(void) struct of_changeset chgset; of_changeset_init(&chgset); - n1 = __of_node_alloc("/testcase-data/changeset/n1", GFP_KERNEL); + n1 = __of_node_dup(NULL, "/testcase-data/changeset/n1"); selftest(n1, "testcase setup failure\n"); - n2 = __of_node_alloc("/testcase-data/changeset/n2", GFP_KERNEL); + n2 = __of_node_dup(NULL, "/testcase-data/changeset/n2"); selftest(n2, "testcase setup failure\n"); - n21 = __of_node_alloc("/testcase-data/changeset/n2/n21", GFP_KERNEL); + n21 = __of_node_dup(NULL, "%s/%s", "/testcase-data/changeset/n2", "n21"); selftest(n21, "testcase setup failure %p\n", n21); nremove = of_find_node_by_path("/testcase-data/changeset/node-remove"); selftest(nremove, "testcase setup failure\n"); diff --git a/include/linux/of.h b/include/linux/of.h index 2cde26e9fb5f..c00415ccec4b 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -23,6 +23,7 @@ #include <linux/spinlock.h> #include <linux/topology.h> #include <linux/notifier.h> +#include <linux/list.h> #include <asm/byteorder.h> #include <asm/errno.h> @@ -134,6 +135,12 @@ static inline int of_node_check_flag(struct device_node *n, unsigned long flag) return test_bit(flag, &n->_flags); } +static inline int of_node_test_and_set_flag(struct device_node *n, + unsigned long flag) +{ + return test_and_set_bit(flag, &n->_flags); +} + static inline void of_node_set_flag(struct device_node *n, unsigned long flag) { set_bit(flag, &n->_flags); @@ -199,6 +206,8 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size) /* flag descriptions */ #define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */ #define OF_DETACHED 2 /* node has been detached from the device tree */ +#define OF_POPULATED 3 /* device already created for the node */ +#define OF_POPULATED_BUS 4 /* of_platform_populate recursed to children of this node */ #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags) #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags) @@ -863,4 +872,34 @@ static inline int of_reconfig_get_state_change(unsigned long action, /* CONFIG_OF_RESOLVE api */ extern int of_resolve_phandles(struct device_node *tree); +/** + * Overlay support + */ + +#ifdef CONFIG_OF_OVERLAY + +/* ID based overlays; the API for external users */ +int of_overlay_create(struct device_node *tree); +int of_overlay_destroy(int id); +int of_overlay_destroy_all(void); + +#else + +static inline int of_overlay_create(struct device_node *tree) +{ + return -ENOTSUPP; +} + +static inline int of_overlay_destroy(int id) +{ + return -ENOTSUPP; +} + +static inline int of_overlay_destroy_all(void) +{ + return -ENOTSUPP; +} + +#endif + #endif /* _LINUX_OF_H */ diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h index 2a93b64a3869..30ebd762063a 100644 --- a/include/linux/of_platform.h +++ b/include/linux/of_platform.h @@ -95,6 +95,7 @@ extern int of_platform_populate(struct device_node *root, const struct of_device_id *matches, const struct of_dev_auxdata *lookup, struct device *parent); +extern void of_platform_depopulate(struct device *parent); #endif /* CONFIG_OF_ADDRESS */ #endif /* CONFIG_OF_DEVICE */ @@ -109,6 +110,13 @@ static inline int of_platform_populate(struct device_node *root, { return -ENODEV; } -#endif /* !CONFIG_OF_ADDRESS */ +static inline void of_platform_depopulate(struct device *parent) { } +#endif + +#ifdef CONFIG_OF_DYNAMIC +extern void of_platform_register_reconfig_notifier(void); +#else +static inline void of_platform_register_reconfig_notifier(void) { } +#endif #endif /* _LINUX_OF_PLATFORM_H */ |