diff options
Diffstat (limited to 'kernel/drivers/of/device.c')
| -rw-r--r-- | kernel/drivers/of/device.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/kernel/drivers/of/device.c b/kernel/drivers/of/device.c new file mode 100644 index 000000000..20c1332a0 --- /dev/null +++ b/kernel/drivers/of/device.c @@ -0,0 +1,276 @@ +#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/dma-mapping.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> + +#include <asm/errno.h> +#include "of_private.h" + +/** + * of_match_device - Tell if a struct device matches an of_device_id list + * @ids: 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)) + return NULL; + return of_match_node(matches, dev->of_node); +} +EXPORT_SYMBOL(of_match_device); + +struct platform_device *of_dev_get(struct platform_device *dev) +{ + struct device *tmp; + + if (!dev) + return NULL; + tmp = get_device(&dev->dev); + if (tmp) + return to_platform_device(tmp); + else + return NULL; +} +EXPORT_SYMBOL(of_dev_get); + +void of_dev_put(struct platform_device *dev) +{ + if (dev) + put_device(&dev->dev); +} +EXPORT_SYMBOL(of_dev_put); + +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 = -1; + + /* device_add will assume that this device is on the same node as + * the parent. If there is no parent defined, set the node + * explicitly */ + if (!ofdev->dev.parent) + set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); + + return device_add(&ofdev->dev); +} + +/** + * of_dma_configure - Setup DMA configuration + * @dev: Device to apply DMA configuration + * @np: Pointer to OF node having DMA configuration + * + * 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. + */ +void of_dma_configure(struct device *dev, struct device_node *np) +{ + u64 dma_addr, paddr, size; + int ret; + bool coherent; + unsigned long offset; + struct iommu_ops *iommu; + + /* + * Set default coherent_dma_mask to 32 bit. Drivers are expected to + * setup the correct supported mask. + */ + if (!dev->coherent_dma_mask) + dev->coherent_dma_mask = DMA_BIT_MASK(32); + + /* + * Set it to coherent_dma_mask by default if the architecture + * code has not set it. + */ + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; + + ret = of_dma_get_range(np, &dma_addr, &paddr, &size); + if (ret < 0) { + dma_addr = offset = 0; + size = dev->coherent_dma_mask + 1; + } else { + offset = PFN_DOWN(paddr - dma_addr); + + /* + * 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\n", + size); + size = size + 1; + } + + if (!size) { + dev_err(dev, "Adjusted size 0x%llx invalid\n", size); + return; + } + dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset); + } + + dev->dma_pfn_offset = offset; + + /* + * Limit coherent and dma mask based on size and default mask + * set by the driver. + */ + dev->coherent_dma_mask = min(dev->coherent_dma_mask, + DMA_BIT_MASK(ilog2(dma_addr + size))); + *dev->dma_mask = min((*dev->dma_mask), + DMA_BIT_MASK(ilog2(dma_addr + size))); + + coherent = of_dma_is_coherent(np); + dev_dbg(dev, "device is%sdma coherent\n", + coherent ? " " : " not "); + + iommu = of_iommu_configure(dev, np); + dev_dbg(dev, "device is%sbehind an iommu\n", + iommu ? " " : " not "); + + arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); +} +EXPORT_SYMBOL_GPL(of_dma_configure); + +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); + +ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) +{ + const char *compat; + int cplen, i; + ssize_t tsize, csize, repend; + + if ((!dev) || (!dev->of_node)) + return -ENODEV; + + /* Name & Type */ + csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name, + dev->of_node->type); + + /* Get compatible property if any */ + compat = of_get_property(dev->of_node, "compatible", &cplen); + if (!compat) + return csize; + + /* Find true end (we tolerate multiple \0 at the end */ + for (i = (cplen - 1); i >= 0 && !compat[i]; i--) + cplen--; + if (!cplen) + return csize; + cplen++; + + /* Check space (need cplen+1 chars including final \0) */ + tsize = csize + cplen; + repend = tsize; + + if (csize >= len) /* @ the limit, all is already filled */ + return tsize; + + if (tsize >= len) { /* limit compat list */ + cplen = len - csize - 1; + repend = len; + } + + /* Copy and do char replacement */ + memcpy(&str[csize + 1], compat, cplen); + for (i = csize; i < repend; i++) { + char c = str[i]; + if (c == '\0') + str[i] = 'C'; + else if (c == ' ') + str[i] = '_'; + } + + return tsize; +} + +/** + * of_device_uevent - Display OF related uevent information + */ +void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + const char *compat; + struct alias_prop *app; + int seen = 0, cplen, sl; + + if ((!dev) || (!dev->of_node)) + return; + + add_uevent_var(env, "OF_NAME=%s", dev->of_node->name); + add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name); + if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0) + add_uevent_var(env, "OF_TYPE=%s", dev->of_node->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. */ + compat = of_get_property(dev->of_node, "compatible", &cplen); + while (compat && *compat && cplen > 0) { + add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); + sl = strlen(compat) + 1; + compat += sl; + cplen -= sl; + 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; +} |