linux/drivers/of/device.c

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// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_iommu.h>
#include <linux/of_reserved_mem.h>
#include <linux/dma-direct.h> /* for bus_dma_region */
#include <linux/dma-map-ops.h>
#include <linux/init.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
#include <linux/platform_device.h>
#include <asm/errno.h>
#include "of_private.h"
/**
* of_match_device - Tell if a struct device matches an of_device_id list
* @matches: array of of device match structures to search in
* @dev: the of device structure to match against
*
* Used by a driver to check whether an platform_device present in the
* system is in its list of supported devices.
*/
const struct of_device_id *of_match_device(const struct of_device_id *matches,
const struct device *dev)
{
if (!matches || !dev->of_node || dev->of_node_reused)
return NULL;
return of_match_node(matches, dev->of_node);
}
EXPORT_SYMBOL(of_match_device);
int of_device_add(struct platform_device *ofdev)
{
BUG_ON(ofdev->dev.of_node == NULL);
/* name and id have to be set so that the platform bus doesn't get
* confused on matching */
ofdev->name = dev_name(&ofdev->dev);
ofdev->id = PLATFORM_DEVID_NONE;
/*
* If this device has not binding numa node in devicetree, that is
* of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
* device is on the same node as the parent.
*/
set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
return device_add(&ofdev->dev);
}
static void
of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
{
struct device_node *node, *of_node = dev->of_node;
int count, i;
if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
return;
count = of_property_count_elems_of_size(of_node, "memory-region",
sizeof(u32));
/*
* If dev->of_node doesn't exist or doesn't contain memory-region, try
* the OF node having DMA configuration.
*/
if (count <= 0) {
of_node = np;
count = of_property_count_elems_of_size(
of_node, "memory-region", sizeof(u32));
}
for (i = 0; i < count; i++) {
node = of_parse_phandle(of_node, "memory-region", i);
/*
* There might be multiple memory regions, but only one
* restricted-dma-pool region is allowed.
*/
if (of_device_is_compatible(node, "restricted-dma-pool") &&
of_device_is_available(node)) {
of_node_put(node);
break;
}
of_node_put(node);
}
/*
* Attempt to initialize a restricted-dma-pool region if one was found.
* Note that count can hold a negative error code.
*/
if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
}
/**
* of_dma_configure_id - Setup DMA configuration
* @dev: Device to apply DMA configuration
* @np: Pointer to OF node having DMA configuration
* @force_dma: Whether device is to be set up by of_dma_configure() even if
* DMA capability is not explicitly described by firmware.
* @id: Optional const pointer value input id
*
* Try to get devices's DMA configuration from DT and update it
* accordingly.
*
* If platform code needs to use its own special DMA configuration, it
* can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
* to fix up DMA configuration.
*/
int of_dma_configure_id(struct device *dev, struct device_node *np,
bool force_dma, const u32 *id)
{
const struct iommu_ops *iommu;
const struct bus_dma_region *map = NULL;
struct device_node *bus_np;
u64 dma_start = 0;
u64 mask, end, size = 0;
bool coherent;
int ret;
if (np == dev->of_node)
bus_np = __of_get_dma_parent(np);
else
bus_np = of_node_get(np);
ret = of_dma_get_range(bus_np, &map);
of_node_put(bus_np);
if (ret < 0) {
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
/*
* For legacy reasons, we have to assume some devices need
* DMA configuration regardless of whether "dma-ranges" is
* correctly specified or not.
*/
if (!force_dma)
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
return ret == -ENODEV ? 0 : ret;
} else {
const struct bus_dma_region *r = map;
u64 dma_end = 0;
/* Determine the overall bounds of all DMA regions */
for (dma_start = ~0; r->size; r++) {
/* Take lower and upper limits */
if (r->dma_start < dma_start)
dma_start = r->dma_start;
if (r->dma_start + r->size > dma_end)
dma_end = r->dma_start + r->size;
}
size = dma_end - dma_start;
/*
* Add a work around to treat the size as mask + 1 in case
* it is defined in DT as a mask.
*/
if (size & 1) {
dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
size);
size = size + 1;
}
if (!size) {
dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
kfree(map);
return -EINVAL;
}
}
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
/*
* If @dev is expected to be DMA-capable then the bus code that created
* it should have initialised its dma_mask pointer by this point. For
* now, we'll continue the legacy behaviour of coercing it to the
* coherent mask if not, but we'll no longer do so quietly.
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
*/
if (!dev->dma_mask) {
dev_warn(dev, "DMA mask not set\n");
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
dev->dma_mask = &dev->coherent_dma_mask;
}
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
if (!size && dev->coherent_dma_mask)
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
else if (!size)
size = 1ULL << 32;
of: restrict DMA configuration Moving DMA configuration to happen later at driver probe time had the unnoticed side-effect that we now perform DMA configuration for *every* device represented in DT, rather than only those explicitly created by the of_platform and PCI code. As Christoph points out, this is not really the best thing to do. Whilst there may well be other DMA-capable buses that can benefit from having their children automatically configured after the bridge has probed, there are also plenty of others like USB, MDIO, etc. that definitely do not support DMA and should not be indiscriminately processed. The good news is that in most cases the DT "dma-ranges" property serves as an appropriate indicator - per a strict interpretation of the spec, anything lacking a "dma-ranges" property should be considered not to have a mapping of DMA address space from its children to its parent, thus anything for which of_dma_get_range() does not succeed does not need DMA configuration. Certain bus types have a general expectation of DMA capability and carry a well-established precedent that an absent "dma-ranges" implies the same as the empty property, so we automatically opt those in to DMA configuration regardless, to avoid regressing most existing platforms. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-31 18:32:54 +08:00
/*
* Limit coherent and dma mask based on size and default mask
* set by the driver.
*/
end = dma_start + size - 1;
mask = DMA_BIT_MASK(ilog2(end) + 1);
of: fix DMA mask generation Historically, DMA masks have suffered some ambiguity between whether they represent the range of physical memory a device can access, or the address bits a device is capable of driving, particularly since on many platforms the two are equivalent. Whilst there are some stragglers left (dma_max_pfn(), I'm looking at you...), the majority of DMA code has been cleaned up to follow the latter definition, not least since it is the only one which makes sense once IOMMUs are involved. In this respect, of_dma_configure() has always done the wrong thing in how it generates initial masks based on "dma-ranges". Although rounding down did not affect the TI Keystone platform where dma_addr + size is already a power of two, in any other case it results in a mask which is at best unnecessarily constrained and at worst unusable. BCM2837 illustrates the problem nicely, where we have a DMA base of 3GB and a size of 1GB - 16MB, giving dma_addr + size = 0xff000000 and a resultant mask of 0x7fffffff, which is then insufficient to even cover the necessary offset, effectively making all DMA addresses out-of-range. This has been hidden until now (mostly because we don't yet prevent drivers from simply overwriting this initial mask later upon probe), but due to recent changes elsewhere now shows up as USB being broken on Raspberry Pi 3. Make it right by rounding up instead of down, such that the mask correctly correctly describes all possisble bits the device needs to emit. Fixes: 9a6d7298b083 ("of: Calculate device DMA masks based on DT dma-range size") Reported-by: Stefan Wahren <stefan.wahren@i2se.com> Reported-by: Andreas Färber <afaerber@suse.de> Reported-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-12 00:29:56 +08:00
dev->coherent_dma_mask &= mask;
*dev->dma_mask &= mask;
/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
if (!ret) {
dev->bus_dma_limit = end;
dev->dma_range_map = map;
}
coherent = of_dma_is_coherent(np);
dev_dbg(dev, "device is%sdma coherent\n",
coherent ? " " : " not ");
iommu = of_iommu_configure(dev, np, id);
if (PTR_ERR(iommu) == -EPROBE_DEFER) {
/* Don't touch range map if it wasn't set from a valid dma-ranges */
if (!ret)
dev->dma_range_map = NULL;
kfree(map);
return -EPROBE_DEFER;
}
dev_dbg(dev, "device is%sbehind an iommu\n",
iommu ? " " : " not ");
arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
if (!iommu)
of_dma_set_restricted_buffer(dev, np);
return 0;
}
EXPORT_SYMBOL_GPL(of_dma_configure_id);
int of_device_register(struct platform_device *pdev)
{
device_initialize(&pdev->dev);
return of_device_add(pdev);
}
EXPORT_SYMBOL(of_device_register);
void of_device_unregister(struct platform_device *ofdev)
{
device_unregister(&ofdev->dev);
}
EXPORT_SYMBOL(of_device_unregister);
const void *of_device_get_match_data(const struct device *dev)
{
const struct of_device_id *match;
match = of_match_device(dev->driver->of_match_table, dev);
if (!match)
return NULL;
return match->data;
}
EXPORT_SYMBOL(of_device_get_match_data);
/**
* of_device_modalias - Fill buffer with newline terminated modalias string
* @dev: Calling device
* @str: Modalias string
* @len: Size of @str
*/
ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
{
ssize_t sl;
if (!dev || !dev->of_node || dev->of_node_reused)
return -ENODEV;
sl = of_modalias(dev->of_node, str, len - 2);
if (sl < 0)
return sl;
if (sl > len - 2)
return -ENOMEM;
str[sl++] = '\n';
str[sl] = 0;
return sl;
}
EXPORT_SYMBOL_GPL(of_device_modalias);
/**
* of_device_uevent - Display OF related uevent information
* @dev: Device to display the uevent information for
* @env: Kernel object's userspace event reference to fill up
*/
void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
const char *compat, *type;
struct alias_prop *app;
struct property *p;
int seen = 0;
if ((!dev) || (!dev->of_node))
return;
add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
type = of_node_get_device_type(dev->of_node);
if (type)
add_uevent_var(env, "OF_TYPE=%s", type);
/* Since the compatible field can contain pretty much anything
* it's not really legal to split it out with commas. We split it
* up using a number of environment variables instead. */
of_property_for_each_string(dev->of_node, "compatible", p, compat) {
add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
seen++;
}
add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
seen = 0;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (dev->of_node == app->np) {
add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
app->alias);
seen++;
}
}
mutex_unlock(&of_mutex);
}
of: device: make of_device_uevent_modalias() take a const device * of_device_uevent_modalias() does not modify the device pointer passed to it, so mark it constant. In order to properly do this, a number of busses need to have a modalias function added as they were attempting to just point to of_device_uevent_modalias instead of their bus-specific modalias function. This is fine except if the prototype for a bus and device type modalias function diverges and then problems could happen. To prevent all of that, just wrap the call to of_device_uevent_modalias() directly for each bus and device type individually. Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Jernej Skrabec <jernej.skrabec@gmail.com> Cc: Samuel Holland <samuel@sholland.org> Cc: David Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Liang He <windhl@126.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Corentin Labbe <clabbe@baylibre.com> Cc: Zou Wei <zou_wei@huawei.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-sunxi@lists.linux.dev Cc: dri-devel@lists.freedesktop.org Cc: devicetree@vger.kernel.org Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-11 19:30:03 +08:00
int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
{
int sl;
if ((!dev) || (!dev->of_node) || dev->of_node_reused)
return -ENODEV;
/* Devicetree modalias is tricky, we add it in 2 steps */
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
sizeof(env->buf) - env->buflen);
if (sl < 0)
return sl;
if (sl >= (sizeof(env->buf) - env->buflen))
return -ENOMEM;
env->buflen += sl;
return 0;
}
EXPORT_SYMBOL_GPL(of_device_uevent_modalias);