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1// SPDX-License-Identifier: GPL-2.02#include <linux/kernel.h>3#include <linux/of.h>4#include <linux/of_device.h>5#include <linux/of_address.h>6#include <linux/of_iommu.h>7#include <linux/of_reserved_mem.h>8#include <linux/dma-direct.h> /* for bus_dma_region */9#include <linux/dma-map-ops.h>10#include <linux/init.h>11#include <linux/mod_devicetable.h>12#include <linux/slab.h>13#include <linux/platform_device.h>14 15#include <asm/errno.h>16#include "of_private.h"17 18/**19 * of_match_device - Tell if a struct device matches an of_device_id list20 * @matches: array of of device match structures to search in21 * @dev: the of device structure to match against22 *23 * Used by a driver to check whether an platform_device present in the24 * system is in its list of supported devices.25 */26const struct of_device_id *of_match_device(const struct of_device_id *matches,27 const struct device *dev)28{29 if (!matches || !dev->of_node || dev->of_node_reused)30 return NULL;31 return of_match_node(matches, dev->of_node);32}33EXPORT_SYMBOL(of_match_device);34 35static void36of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)37{38 struct device_node *node, *of_node = dev->of_node;39 int count, i;40 41 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))42 return;43 44 count = of_property_count_elems_of_size(of_node, "memory-region",45 sizeof(u32));46 /*47 * If dev->of_node doesn't exist or doesn't contain memory-region, try48 * the OF node having DMA configuration.49 */50 if (count <= 0) {51 of_node = np;52 count = of_property_count_elems_of_size(53 of_node, "memory-region", sizeof(u32));54 }55 56 for (i = 0; i < count; i++) {57 node = of_parse_phandle(of_node, "memory-region", i);58 /*59 * There might be multiple memory regions, but only one60 * restricted-dma-pool region is allowed.61 */62 if (of_device_is_compatible(node, "restricted-dma-pool") &&63 of_device_is_available(node)) {64 of_node_put(node);65 break;66 }67 of_node_put(node);68 }69 70 /*71 * Attempt to initialize a restricted-dma-pool region if one was found.72 * Note that count can hold a negative error code.73 */74 if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))75 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");76}77 78/**79 * of_dma_configure_id - Setup DMA configuration80 * @dev: Device to apply DMA configuration81 * @np: Pointer to OF node having DMA configuration82 * @force_dma: Whether device is to be set up by of_dma_configure() even if83 * DMA capability is not explicitly described by firmware.84 * @id: Optional const pointer value input id85 *86 * Try to get devices's DMA configuration from DT and update it87 * accordingly.88 *89 * If platform code needs to use its own special DMA configuration, it90 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events91 * to fix up DMA configuration.92 */93int of_dma_configure_id(struct device *dev, struct device_node *np,94 bool force_dma, const u32 *id)95{96 const struct bus_dma_region *map = NULL;97 struct device_node *bus_np;98 u64 mask, end = 0;99 bool coherent, set_map = false;100 int ret;101 102 if (np == dev->of_node)103 bus_np = __of_get_dma_parent(np);104 else105 bus_np = of_node_get(np);106 107 ret = of_dma_get_range(bus_np, &map);108 of_node_put(bus_np);109 if (ret < 0) {110 /*111 * For legacy reasons, we have to assume some devices need112 * DMA configuration regardless of whether "dma-ranges" is113 * correctly specified or not.114 */115 if (!force_dma)116 return ret == -ENODEV ? 0 : ret;117 } else {118 /* Determine the overall bounds of all DMA regions */119 end = dma_range_map_max(map);120 set_map = true;121 }122 123 /*124 * If @dev is expected to be DMA-capable then the bus code that created125 * it should have initialised its dma_mask pointer by this point. For126 * now, we'll continue the legacy behaviour of coercing it to the127 * coherent mask if not, but we'll no longer do so quietly.128 */129 if (!dev->dma_mask) {130 dev_warn(dev, "DMA mask not set\n");131 dev->dma_mask = &dev->coherent_dma_mask;132 }133 134 if (!end && dev->coherent_dma_mask)135 end = dev->coherent_dma_mask;136 else if (!end)137 end = (1ULL << 32) - 1;138 139 /*140 * Limit coherent and dma mask based on size and default mask141 * set by the driver.142 */143 mask = DMA_BIT_MASK(ilog2(end) + 1);144 dev->coherent_dma_mask &= mask;145 *dev->dma_mask &= mask;146 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */147 if (set_map) {148 dev->bus_dma_limit = end;149 dev->dma_range_map = map;150 }151 152 coherent = of_dma_is_coherent(np);153 dev_dbg(dev, "device is%sdma coherent\n",154 coherent ? " " : " not ");155 156 ret = of_iommu_configure(dev, np, id);157 if (ret == -EPROBE_DEFER) {158 /* Don't touch range map if it wasn't set from a valid dma-ranges */159 if (set_map)160 dev->dma_range_map = NULL;161 kfree(map);162 return -EPROBE_DEFER;163 }164 /* Take all other IOMMU errors to mean we'll just carry on without it */165 dev_dbg(dev, "device is%sbehind an iommu\n",166 !ret ? " " : " not ");167 168 arch_setup_dma_ops(dev, coherent);169 170 if (ret)171 of_dma_set_restricted_buffer(dev, np);172 173 return 0;174}175EXPORT_SYMBOL_GPL(of_dma_configure_id);176 177const void *of_device_get_match_data(const struct device *dev)178{179 const struct of_device_id *match;180 181 match = of_match_device(dev->driver->of_match_table, dev);182 if (!match)183 return NULL;184 185 return match->data;186}187EXPORT_SYMBOL(of_device_get_match_data);188 189/**190 * of_device_modalias - Fill buffer with newline terminated modalias string191 * @dev: Calling device192 * @str: Modalias string193 * @len: Size of @str194 */195ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)196{197 ssize_t sl;198 199 if (!dev || !dev->of_node || dev->of_node_reused)200 return -ENODEV;201 202 sl = of_modalias(dev->of_node, str, len - 2);203 if (sl < 0)204 return sl;205 if (sl > len - 2)206 return -ENOMEM;207 208 str[sl++] = '\n';209 str[sl] = 0;210 return sl;211}212EXPORT_SYMBOL_GPL(of_device_modalias);213 214/**215 * of_device_uevent - Display OF related uevent information216 * @dev: Device to display the uevent information for217 * @env: Kernel object's userspace event reference to fill up218 */219void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)220{221 const char *compat, *type;222 struct alias_prop *app;223 struct property *p;224 int seen = 0;225 226 if ((!dev) || (!dev->of_node))227 return;228 229 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);230 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);231 type = of_node_get_device_type(dev->of_node);232 if (type)233 add_uevent_var(env, "OF_TYPE=%s", type);234 235 /* Since the compatible field can contain pretty much anything236 * it's not really legal to split it out with commas. We split it237 * up using a number of environment variables instead. */238 of_property_for_each_string(dev->of_node, "compatible", p, compat) {239 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);240 seen++;241 }242 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);243 244 seen = 0;245 mutex_lock(&of_mutex);246 list_for_each_entry(app, &aliases_lookup, link) {247 if (dev->of_node == app->np) {248 add_uevent_var(env, "OF_ALIAS_%d=%s", seen,249 app->alias);250 seen++;251 }252 }253 mutex_unlock(&of_mutex);254}255EXPORT_SYMBOL_GPL(of_device_uevent);256 257int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)258{259 int sl;260 261 if ((!dev) || (!dev->of_node) || dev->of_node_reused)262 return -ENODEV;263 264 /* Devicetree modalias is tricky, we add it in 2 steps */265 if (add_uevent_var(env, "MODALIAS="))266 return -ENOMEM;267 268 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],269 sizeof(env->buf) - env->buflen);270 if (sl < 0)271 return sl;272 if (sl >= (sizeof(env->buf) - env->buflen))273 return -ENOMEM;274 env->buflen += sl;275 276 return 0;277}278EXPORT_SYMBOL_GPL(of_device_uevent_modalias);279 280/**281 * of_device_make_bus_id - Use the device node data to assign a unique name282 * @dev: pointer to device structure that is linked to a device tree node283 *284 * This routine will first try using the translated bus address to285 * derive a unique name. If it cannot, then it will prepend names from286 * parent nodes until a unique name can be derived.287 */288void of_device_make_bus_id(struct device *dev)289{290 struct device_node *node = dev->of_node;291 const __be32 *reg;292 u64 addr;293 u32 mask;294 295 /* Construct the name, using parent nodes if necessary to ensure uniqueness */296 while (node->parent) {297 /*298 * If the address can be translated, then that is as much299 * uniqueness as we need. Make it the first component and return300 */301 reg = of_get_property(node, "reg", NULL);302 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {303 if (!of_property_read_u32(node, "mask", &mask))304 dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",305 addr, ffs(mask) - 1, node, dev_name(dev));306 307 else308 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",309 addr, node, dev_name(dev));310 return;311 }312 313 /* format arguments only used if dev_name() resolves to NULL */314 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",315 kbasename(node->full_name), dev_name(dev));316 node = node->parent;317 }318}319EXPORT_SYMBOL_GPL(of_device_make_bus_id);320