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Diffstat (limited to '')
| -rw-r--r-- | drivers/of/device.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/of/device.c b/drivers/of/device.c new file mode 100644 index 000000000..ce225d259 --- /dev/null +++ b/drivers/of/device.c @@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/string.h> +#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/module.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> +#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) { + /* + * 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) + 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; + } + } + + /* + * 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. + */ + if (!dev->dma_mask) { + dev_warn(dev, "DMA mask not set\n"); + dev->dma_mask = &dev->coherent_dma_mask; + } + + if (!size && dev->coherent_dma_mask) + size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); + else if (!size) + size = 1ULL << 32; + + /* + * 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); + 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); + +static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) +{ + const char *compat; + char *c; + struct property *p; + ssize_t csize; + ssize_t tsize; + + if ((!dev) || (!dev->of_node)) + return -ENODEV; + + /* Name & Type */ + /* %p eats all alphanum characters, so %c must be used here */ + csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', + of_node_get_device_type(dev->of_node)); + tsize = csize; + len -= csize; + if (str) + str += csize; + + of_property_for_each_string(dev->of_node, "compatible", p, compat) { + csize = strlen(compat) + 1; + tsize += csize; + if (csize > len) + continue; + + csize = snprintf(str, len, "C%s", compat); + for (c = str; c; ) { + c = strchr(c, ' '); + if (c) + *c++ = '_'; + } + len -= csize; + str += csize; + } + + return tsize; +} + +int of_device_request_module(struct device *dev) +{ + char *str; + ssize_t size; + int ret; + + size = of_device_get_modalias(dev, NULL, 0); + if (size < 0) + return size; + + /* Reserve an additional byte for the trailing '\0' */ + size++; + + str = kmalloc(size, GFP_KERNEL); + if (!str) + return -ENOMEM; + + of_device_get_modalias(dev, str, size); + str[size - 1] = '\0'; + ret = request_module(str); + kfree(str); + + return ret; +} +EXPORT_SYMBOL_GPL(of_device_request_module); + +/** + * 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 = of_device_get_modalias(dev, 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 apply DMA configuration + * @env: Kernel object's userspace event reference + */ +void of_device_uevent(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); +} + +int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) +{ + int sl; + + if ((!dev) || (!dev->of_node)) + return -ENODEV; + + /* Devicetree modalias is tricky, we add it in 2 steps */ + if (add_uevent_var(env, "MODALIAS=")) + return -ENOMEM; + + sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], + sizeof(env->buf) - env->buflen); + if (sl >= (sizeof(env->buf) - env->buflen)) + return -ENOMEM; + env->buflen += sl; + + return 0; +} +EXPORT_SYMBOL_GPL(of_device_uevent_modalias); |