18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0
28c2ecf20Sopenharmony_ci#include <linux/string.h>
38c2ecf20Sopenharmony_ci#include <linux/kernel.h>
48c2ecf20Sopenharmony_ci#include <linux/of.h>
58c2ecf20Sopenharmony_ci#include <linux/of_device.h>
68c2ecf20Sopenharmony_ci#include <linux/of_address.h>
78c2ecf20Sopenharmony_ci#include <linux/of_iommu.h>
88c2ecf20Sopenharmony_ci#include <linux/dma-direct.h> /* for bus_dma_region */
98c2ecf20Sopenharmony_ci#include <linux/dma-map-ops.h>
108c2ecf20Sopenharmony_ci#include <linux/init.h>
118c2ecf20Sopenharmony_ci#include <linux/module.h>
128c2ecf20Sopenharmony_ci#include <linux/mod_devicetable.h>
138c2ecf20Sopenharmony_ci#include <linux/slab.h>
148c2ecf20Sopenharmony_ci#include <linux/platform_device.h>
158c2ecf20Sopenharmony_ci
168c2ecf20Sopenharmony_ci#include <asm/errno.h>
178c2ecf20Sopenharmony_ci#include "of_private.h"
188c2ecf20Sopenharmony_ci
198c2ecf20Sopenharmony_ci/**
208c2ecf20Sopenharmony_ci * of_match_device - Tell if a struct device matches an of_device_id list
218c2ecf20Sopenharmony_ci * @matches: array of of device match structures to search in
228c2ecf20Sopenharmony_ci * @dev: the of device structure to match against
238c2ecf20Sopenharmony_ci *
248c2ecf20Sopenharmony_ci * Used by a driver to check whether an platform_device present in the
258c2ecf20Sopenharmony_ci * system is in its list of supported devices.
268c2ecf20Sopenharmony_ci */
278c2ecf20Sopenharmony_ciconst struct of_device_id *of_match_device(const struct of_device_id *matches,
288c2ecf20Sopenharmony_ci					   const struct device *dev)
298c2ecf20Sopenharmony_ci{
308c2ecf20Sopenharmony_ci	if ((!matches) || (!dev->of_node))
318c2ecf20Sopenharmony_ci		return NULL;
328c2ecf20Sopenharmony_ci	return of_match_node(matches, dev->of_node);
338c2ecf20Sopenharmony_ci}
348c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_match_device);
358c2ecf20Sopenharmony_ci
368c2ecf20Sopenharmony_cistruct platform_device *of_dev_get(struct platform_device *dev)
378c2ecf20Sopenharmony_ci{
388c2ecf20Sopenharmony_ci	struct device *tmp;
398c2ecf20Sopenharmony_ci
408c2ecf20Sopenharmony_ci	if (!dev)
418c2ecf20Sopenharmony_ci		return NULL;
428c2ecf20Sopenharmony_ci	tmp = get_device(&dev->dev);
438c2ecf20Sopenharmony_ci	if (tmp)
448c2ecf20Sopenharmony_ci		return to_platform_device(tmp);
458c2ecf20Sopenharmony_ci	else
468c2ecf20Sopenharmony_ci		return NULL;
478c2ecf20Sopenharmony_ci}
488c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_dev_get);
498c2ecf20Sopenharmony_ci
508c2ecf20Sopenharmony_civoid of_dev_put(struct platform_device *dev)
518c2ecf20Sopenharmony_ci{
528c2ecf20Sopenharmony_ci	if (dev)
538c2ecf20Sopenharmony_ci		put_device(&dev->dev);
548c2ecf20Sopenharmony_ci}
558c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_dev_put);
568c2ecf20Sopenharmony_ci
578c2ecf20Sopenharmony_ciint of_device_add(struct platform_device *ofdev)
588c2ecf20Sopenharmony_ci{
598c2ecf20Sopenharmony_ci	BUG_ON(ofdev->dev.of_node == NULL);
608c2ecf20Sopenharmony_ci
618c2ecf20Sopenharmony_ci	/* name and id have to be set so that the platform bus doesn't get
628c2ecf20Sopenharmony_ci	 * confused on matching */
638c2ecf20Sopenharmony_ci	ofdev->name = dev_name(&ofdev->dev);
648c2ecf20Sopenharmony_ci	ofdev->id = PLATFORM_DEVID_NONE;
658c2ecf20Sopenharmony_ci
668c2ecf20Sopenharmony_ci	/*
678c2ecf20Sopenharmony_ci	 * If this device has not binding numa node in devicetree, that is
688c2ecf20Sopenharmony_ci	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
698c2ecf20Sopenharmony_ci	 * device is on the same node as the parent.
708c2ecf20Sopenharmony_ci	 */
718c2ecf20Sopenharmony_ci	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
728c2ecf20Sopenharmony_ci
738c2ecf20Sopenharmony_ci	return device_add(&ofdev->dev);
748c2ecf20Sopenharmony_ci}
758c2ecf20Sopenharmony_ci
768c2ecf20Sopenharmony_ci/**
778c2ecf20Sopenharmony_ci * of_dma_configure - Setup DMA configuration
788c2ecf20Sopenharmony_ci * @dev:	Device to apply DMA configuration
798c2ecf20Sopenharmony_ci * @np:		Pointer to OF node having DMA configuration
808c2ecf20Sopenharmony_ci * @force_dma:  Whether device is to be set up by of_dma_configure() even if
818c2ecf20Sopenharmony_ci *		DMA capability is not explicitly described by firmware.
828c2ecf20Sopenharmony_ci * @id:		Optional const pointer value input id
838c2ecf20Sopenharmony_ci *
848c2ecf20Sopenharmony_ci * Try to get devices's DMA configuration from DT and update it
858c2ecf20Sopenharmony_ci * accordingly.
868c2ecf20Sopenharmony_ci *
878c2ecf20Sopenharmony_ci * If platform code needs to use its own special DMA configuration, it
888c2ecf20Sopenharmony_ci * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
898c2ecf20Sopenharmony_ci * to fix up DMA configuration.
908c2ecf20Sopenharmony_ci */
918c2ecf20Sopenharmony_ciint of_dma_configure_id(struct device *dev, struct device_node *np,
928c2ecf20Sopenharmony_ci			bool force_dma, const u32 *id)
938c2ecf20Sopenharmony_ci{
948c2ecf20Sopenharmony_ci	const struct iommu_ops *iommu;
958c2ecf20Sopenharmony_ci	const struct bus_dma_region *map = NULL;
968c2ecf20Sopenharmony_ci	u64 dma_start = 0;
978c2ecf20Sopenharmony_ci	u64 mask, end, size = 0;
988c2ecf20Sopenharmony_ci	bool coherent;
998c2ecf20Sopenharmony_ci	int ret;
1008c2ecf20Sopenharmony_ci
1018c2ecf20Sopenharmony_ci	ret = of_dma_get_range(np, &map);
1028c2ecf20Sopenharmony_ci	if (ret < 0) {
1038c2ecf20Sopenharmony_ci		/*
1048c2ecf20Sopenharmony_ci		 * For legacy reasons, we have to assume some devices need
1058c2ecf20Sopenharmony_ci		 * DMA configuration regardless of whether "dma-ranges" is
1068c2ecf20Sopenharmony_ci		 * correctly specified or not.
1078c2ecf20Sopenharmony_ci		 */
1088c2ecf20Sopenharmony_ci		if (!force_dma)
1098c2ecf20Sopenharmony_ci			return ret == -ENODEV ? 0 : ret;
1108c2ecf20Sopenharmony_ci	} else {
1118c2ecf20Sopenharmony_ci		const struct bus_dma_region *r = map;
1128c2ecf20Sopenharmony_ci		u64 dma_end = 0;
1138c2ecf20Sopenharmony_ci
1148c2ecf20Sopenharmony_ci		/* Determine the overall bounds of all DMA regions */
1158c2ecf20Sopenharmony_ci		for (dma_start = ~0; r->size; r++) {
1168c2ecf20Sopenharmony_ci			/* Take lower and upper limits */
1178c2ecf20Sopenharmony_ci			if (r->dma_start < dma_start)
1188c2ecf20Sopenharmony_ci				dma_start = r->dma_start;
1198c2ecf20Sopenharmony_ci			if (r->dma_start + r->size > dma_end)
1208c2ecf20Sopenharmony_ci				dma_end = r->dma_start + r->size;
1218c2ecf20Sopenharmony_ci		}
1228c2ecf20Sopenharmony_ci		size = dma_end - dma_start;
1238c2ecf20Sopenharmony_ci
1248c2ecf20Sopenharmony_ci		/*
1258c2ecf20Sopenharmony_ci		 * Add a work around to treat the size as mask + 1 in case
1268c2ecf20Sopenharmony_ci		 * it is defined in DT as a mask.
1278c2ecf20Sopenharmony_ci		 */
1288c2ecf20Sopenharmony_ci		if (size & 1) {
1298c2ecf20Sopenharmony_ci			dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
1308c2ecf20Sopenharmony_ci				 size);
1318c2ecf20Sopenharmony_ci			size = size + 1;
1328c2ecf20Sopenharmony_ci		}
1338c2ecf20Sopenharmony_ci
1348c2ecf20Sopenharmony_ci		if (!size) {
1358c2ecf20Sopenharmony_ci			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
1368c2ecf20Sopenharmony_ci			kfree(map);
1378c2ecf20Sopenharmony_ci			return -EINVAL;
1388c2ecf20Sopenharmony_ci		}
1398c2ecf20Sopenharmony_ci	}
1408c2ecf20Sopenharmony_ci
1418c2ecf20Sopenharmony_ci	/*
1428c2ecf20Sopenharmony_ci	 * If @dev is expected to be DMA-capable then the bus code that created
1438c2ecf20Sopenharmony_ci	 * it should have initialised its dma_mask pointer by this point. For
1448c2ecf20Sopenharmony_ci	 * now, we'll continue the legacy behaviour of coercing it to the
1458c2ecf20Sopenharmony_ci	 * coherent mask if not, but we'll no longer do so quietly.
1468c2ecf20Sopenharmony_ci	 */
1478c2ecf20Sopenharmony_ci	if (!dev->dma_mask) {
1488c2ecf20Sopenharmony_ci		dev_warn(dev, "DMA mask not set\n");
1498c2ecf20Sopenharmony_ci		dev->dma_mask = &dev->coherent_dma_mask;
1508c2ecf20Sopenharmony_ci	}
1518c2ecf20Sopenharmony_ci
1528c2ecf20Sopenharmony_ci	if (!size && dev->coherent_dma_mask)
1538c2ecf20Sopenharmony_ci		size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
1548c2ecf20Sopenharmony_ci	else if (!size)
1558c2ecf20Sopenharmony_ci		size = 1ULL << 32;
1568c2ecf20Sopenharmony_ci
1578c2ecf20Sopenharmony_ci	/*
1588c2ecf20Sopenharmony_ci	 * Limit coherent and dma mask based on size and default mask
1598c2ecf20Sopenharmony_ci	 * set by the driver.
1608c2ecf20Sopenharmony_ci	 */
1618c2ecf20Sopenharmony_ci	end = dma_start + size - 1;
1628c2ecf20Sopenharmony_ci	mask = DMA_BIT_MASK(ilog2(end) + 1);
1638c2ecf20Sopenharmony_ci	dev->coherent_dma_mask &= mask;
1648c2ecf20Sopenharmony_ci	*dev->dma_mask &= mask;
1658c2ecf20Sopenharmony_ci	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
1668c2ecf20Sopenharmony_ci	if (!ret) {
1678c2ecf20Sopenharmony_ci		dev->bus_dma_limit = end;
1688c2ecf20Sopenharmony_ci		dev->dma_range_map = map;
1698c2ecf20Sopenharmony_ci	}
1708c2ecf20Sopenharmony_ci
1718c2ecf20Sopenharmony_ci	coherent = of_dma_is_coherent(np);
1728c2ecf20Sopenharmony_ci	dev_dbg(dev, "device is%sdma coherent\n",
1738c2ecf20Sopenharmony_ci		coherent ? " " : " not ");
1748c2ecf20Sopenharmony_ci
1758c2ecf20Sopenharmony_ci	iommu = of_iommu_configure(dev, np, id);
1768c2ecf20Sopenharmony_ci	if (PTR_ERR(iommu) == -EPROBE_DEFER) {
1778c2ecf20Sopenharmony_ci		/* Don't touch range map if it wasn't set from a valid dma-ranges */
1788c2ecf20Sopenharmony_ci		if (!ret)
1798c2ecf20Sopenharmony_ci			dev->dma_range_map = NULL;
1808c2ecf20Sopenharmony_ci		kfree(map);
1818c2ecf20Sopenharmony_ci		return -EPROBE_DEFER;
1828c2ecf20Sopenharmony_ci	}
1838c2ecf20Sopenharmony_ci
1848c2ecf20Sopenharmony_ci	dev_dbg(dev, "device is%sbehind an iommu\n",
1858c2ecf20Sopenharmony_ci		iommu ? " " : " not ");
1868c2ecf20Sopenharmony_ci
1878c2ecf20Sopenharmony_ci	arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
1888c2ecf20Sopenharmony_ci
1898c2ecf20Sopenharmony_ci	return 0;
1908c2ecf20Sopenharmony_ci}
1918c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(of_dma_configure_id);
1928c2ecf20Sopenharmony_ci
1938c2ecf20Sopenharmony_ciint of_device_register(struct platform_device *pdev)
1948c2ecf20Sopenharmony_ci{
1958c2ecf20Sopenharmony_ci	device_initialize(&pdev->dev);
1968c2ecf20Sopenharmony_ci	return of_device_add(pdev);
1978c2ecf20Sopenharmony_ci}
1988c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_device_register);
1998c2ecf20Sopenharmony_ci
2008c2ecf20Sopenharmony_civoid of_device_unregister(struct platform_device *ofdev)
2018c2ecf20Sopenharmony_ci{
2028c2ecf20Sopenharmony_ci	device_unregister(&ofdev->dev);
2038c2ecf20Sopenharmony_ci}
2048c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_device_unregister);
2058c2ecf20Sopenharmony_ci
2068c2ecf20Sopenharmony_ciconst void *of_device_get_match_data(const struct device *dev)
2078c2ecf20Sopenharmony_ci{
2088c2ecf20Sopenharmony_ci	const struct of_device_id *match;
2098c2ecf20Sopenharmony_ci
2108c2ecf20Sopenharmony_ci	match = of_match_device(dev->driver->of_match_table, dev);
2118c2ecf20Sopenharmony_ci	if (!match)
2128c2ecf20Sopenharmony_ci		return NULL;
2138c2ecf20Sopenharmony_ci
2148c2ecf20Sopenharmony_ci	return match->data;
2158c2ecf20Sopenharmony_ci}
2168c2ecf20Sopenharmony_ciEXPORT_SYMBOL(of_device_get_match_data);
2178c2ecf20Sopenharmony_ci
2188c2ecf20Sopenharmony_cistatic ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
2198c2ecf20Sopenharmony_ci{
2208c2ecf20Sopenharmony_ci	const char *compat;
2218c2ecf20Sopenharmony_ci	char *c;
2228c2ecf20Sopenharmony_ci	struct property *p;
2238c2ecf20Sopenharmony_ci	ssize_t csize;
2248c2ecf20Sopenharmony_ci	ssize_t tsize;
2258c2ecf20Sopenharmony_ci
2268c2ecf20Sopenharmony_ci	if ((!dev) || (!dev->of_node))
2278c2ecf20Sopenharmony_ci		return -ENODEV;
2288c2ecf20Sopenharmony_ci
2298c2ecf20Sopenharmony_ci	/* Name & Type */
2308c2ecf20Sopenharmony_ci	/* %p eats all alphanum characters, so %c must be used here */
2318c2ecf20Sopenharmony_ci	csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
2328c2ecf20Sopenharmony_ci			 of_node_get_device_type(dev->of_node));
2338c2ecf20Sopenharmony_ci	tsize = csize;
2348c2ecf20Sopenharmony_ci	len -= csize;
2358c2ecf20Sopenharmony_ci	if (str)
2368c2ecf20Sopenharmony_ci		str += csize;
2378c2ecf20Sopenharmony_ci
2388c2ecf20Sopenharmony_ci	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
2398c2ecf20Sopenharmony_ci		csize = strlen(compat) + 1;
2408c2ecf20Sopenharmony_ci		tsize += csize;
2418c2ecf20Sopenharmony_ci		if (csize > len)
2428c2ecf20Sopenharmony_ci			continue;
2438c2ecf20Sopenharmony_ci
2448c2ecf20Sopenharmony_ci		csize = snprintf(str, len, "C%s", compat);
2458c2ecf20Sopenharmony_ci		for (c = str; c; ) {
2468c2ecf20Sopenharmony_ci			c = strchr(c, ' ');
2478c2ecf20Sopenharmony_ci			if (c)
2488c2ecf20Sopenharmony_ci				*c++ = '_';
2498c2ecf20Sopenharmony_ci		}
2508c2ecf20Sopenharmony_ci		len -= csize;
2518c2ecf20Sopenharmony_ci		str += csize;
2528c2ecf20Sopenharmony_ci	}
2538c2ecf20Sopenharmony_ci
2548c2ecf20Sopenharmony_ci	return tsize;
2558c2ecf20Sopenharmony_ci}
2568c2ecf20Sopenharmony_ci
2578c2ecf20Sopenharmony_ciint of_device_request_module(struct device *dev)
2588c2ecf20Sopenharmony_ci{
2598c2ecf20Sopenharmony_ci	char *str;
2608c2ecf20Sopenharmony_ci	ssize_t size;
2618c2ecf20Sopenharmony_ci	int ret;
2628c2ecf20Sopenharmony_ci
2638c2ecf20Sopenharmony_ci	size = of_device_get_modalias(dev, NULL, 0);
2648c2ecf20Sopenharmony_ci	if (size < 0)
2658c2ecf20Sopenharmony_ci		return size;
2668c2ecf20Sopenharmony_ci
2678c2ecf20Sopenharmony_ci	/* Reserve an additional byte for the trailing '\0' */
2688c2ecf20Sopenharmony_ci	size++;
2698c2ecf20Sopenharmony_ci
2708c2ecf20Sopenharmony_ci	str = kmalloc(size, GFP_KERNEL);
2718c2ecf20Sopenharmony_ci	if (!str)
2728c2ecf20Sopenharmony_ci		return -ENOMEM;
2738c2ecf20Sopenharmony_ci
2748c2ecf20Sopenharmony_ci	of_device_get_modalias(dev, str, size);
2758c2ecf20Sopenharmony_ci	str[size - 1] = '\0';
2768c2ecf20Sopenharmony_ci	ret = request_module(str);
2778c2ecf20Sopenharmony_ci	kfree(str);
2788c2ecf20Sopenharmony_ci
2798c2ecf20Sopenharmony_ci	return ret;
2808c2ecf20Sopenharmony_ci}
2818c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(of_device_request_module);
2828c2ecf20Sopenharmony_ci
2838c2ecf20Sopenharmony_ci/**
2848c2ecf20Sopenharmony_ci * of_device_modalias - Fill buffer with newline terminated modalias string
2858c2ecf20Sopenharmony_ci */
2868c2ecf20Sopenharmony_cissize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
2878c2ecf20Sopenharmony_ci{
2888c2ecf20Sopenharmony_ci	ssize_t sl = of_device_get_modalias(dev, str, len - 2);
2898c2ecf20Sopenharmony_ci	if (sl < 0)
2908c2ecf20Sopenharmony_ci		return sl;
2918c2ecf20Sopenharmony_ci	if (sl > len - 2)
2928c2ecf20Sopenharmony_ci		return -ENOMEM;
2938c2ecf20Sopenharmony_ci
2948c2ecf20Sopenharmony_ci	str[sl++] = '\n';
2958c2ecf20Sopenharmony_ci	str[sl] = 0;
2968c2ecf20Sopenharmony_ci	return sl;
2978c2ecf20Sopenharmony_ci}
2988c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(of_device_modalias);
2998c2ecf20Sopenharmony_ci
3008c2ecf20Sopenharmony_ci/**
3018c2ecf20Sopenharmony_ci * of_device_uevent - Display OF related uevent information
3028c2ecf20Sopenharmony_ci */
3038c2ecf20Sopenharmony_civoid of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
3048c2ecf20Sopenharmony_ci{
3058c2ecf20Sopenharmony_ci	const char *compat, *type;
3068c2ecf20Sopenharmony_ci	struct alias_prop *app;
3078c2ecf20Sopenharmony_ci	struct property *p;
3088c2ecf20Sopenharmony_ci	int seen = 0;
3098c2ecf20Sopenharmony_ci
3108c2ecf20Sopenharmony_ci	if ((!dev) || (!dev->of_node))
3118c2ecf20Sopenharmony_ci		return;
3128c2ecf20Sopenharmony_ci
3138c2ecf20Sopenharmony_ci	add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
3148c2ecf20Sopenharmony_ci	add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
3158c2ecf20Sopenharmony_ci	type = of_node_get_device_type(dev->of_node);
3168c2ecf20Sopenharmony_ci	if (type)
3178c2ecf20Sopenharmony_ci		add_uevent_var(env, "OF_TYPE=%s", type);
3188c2ecf20Sopenharmony_ci
3198c2ecf20Sopenharmony_ci	/* Since the compatible field can contain pretty much anything
3208c2ecf20Sopenharmony_ci	 * it's not really legal to split it out with commas. We split it
3218c2ecf20Sopenharmony_ci	 * up using a number of environment variables instead. */
3228c2ecf20Sopenharmony_ci	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
3238c2ecf20Sopenharmony_ci		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
3248c2ecf20Sopenharmony_ci		seen++;
3258c2ecf20Sopenharmony_ci	}
3268c2ecf20Sopenharmony_ci	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
3278c2ecf20Sopenharmony_ci
3288c2ecf20Sopenharmony_ci	seen = 0;
3298c2ecf20Sopenharmony_ci	mutex_lock(&of_mutex);
3308c2ecf20Sopenharmony_ci	list_for_each_entry(app, &aliases_lookup, link) {
3318c2ecf20Sopenharmony_ci		if (dev->of_node == app->np) {
3328c2ecf20Sopenharmony_ci			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
3338c2ecf20Sopenharmony_ci				       app->alias);
3348c2ecf20Sopenharmony_ci			seen++;
3358c2ecf20Sopenharmony_ci		}
3368c2ecf20Sopenharmony_ci	}
3378c2ecf20Sopenharmony_ci	mutex_unlock(&of_mutex);
3388c2ecf20Sopenharmony_ci}
3398c2ecf20Sopenharmony_ci
3408c2ecf20Sopenharmony_ciint of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
3418c2ecf20Sopenharmony_ci{
3428c2ecf20Sopenharmony_ci	int sl;
3438c2ecf20Sopenharmony_ci
3448c2ecf20Sopenharmony_ci	if ((!dev) || (!dev->of_node))
3458c2ecf20Sopenharmony_ci		return -ENODEV;
3468c2ecf20Sopenharmony_ci
3478c2ecf20Sopenharmony_ci	/* Devicetree modalias is tricky, we add it in 2 steps */
3488c2ecf20Sopenharmony_ci	if (add_uevent_var(env, "MODALIAS="))
3498c2ecf20Sopenharmony_ci		return -ENOMEM;
3508c2ecf20Sopenharmony_ci
3518c2ecf20Sopenharmony_ci	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
3528c2ecf20Sopenharmony_ci				    sizeof(env->buf) - env->buflen);
3538c2ecf20Sopenharmony_ci	if (sl >= (sizeof(env->buf) - env->buflen))
3548c2ecf20Sopenharmony_ci		return -ENOMEM;
3558c2ecf20Sopenharmony_ci	env->buflen += sl;
3568c2ecf20Sopenharmony_ci
3578c2ecf20Sopenharmony_ci	return 0;
3588c2ecf20Sopenharmony_ci}
3598c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(of_device_uevent_modalias);
360