diff options
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 46 |
1 files changed, 38 insertions, 8 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index c1357d7f3dc6..ca13cd39330b 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -40,6 +40,8 @@ #include <linux/dmaengine.h> #include <linux/hardirq.h> #include <linux/spinlock.h> +#include <linux/of.h> +#include <linux/property.h> #include <linux/percpu.h> #include <linux/rcupdate.h> #include <linux/mutex.h> @@ -812,15 +814,13 @@ static const struct dma_slave_map *dma_filter_match(struct dma_device *device, */ struct dma_chan *dma_request_chan(struct device *dev, const char *name) { + struct fwnode_handle *fwnode = dev_fwnode(dev); struct dma_device *d, *_d; struct dma_chan *chan = NULL; - /* If device-tree is present get slave info from here */ - if (dev->of_node) - chan = of_dma_request_slave_channel(dev->of_node, name); - - /* If device was enumerated by ACPI get slave info from here */ - if (has_acpi_companion(dev) && !chan) + if (is_of_node(fwnode)) + chan = of_dma_request_slave_channel(to_of_node(fwnode), name); + else if (is_acpi_device_node(fwnode)) chan = acpi_dma_request_slave_chan_by_name(dev, name); if (PTR_ERR(chan) == -EPROBE_DEFER) @@ -854,8 +854,8 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) found: #ifdef CONFIG_DEBUG_FS - chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), - name); + chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), name); + /* No functional issue if it fails, users are supposed to test before use */ #endif chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); @@ -926,6 +926,36 @@ void dma_release_channel(struct dma_chan *chan) } EXPORT_SYMBOL_GPL(dma_release_channel); +static void dmaenginem_release_channel(void *chan) +{ + dma_release_channel(chan); +} + +/** + * devm_dma_request_chan - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name + * + * Returns pointer to appropriate DMA channel on success or an error pointer. + * + * The operation is managed and will be undone on driver detach. + */ + +struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name) +{ + struct dma_chan *chan = dma_request_chan(dev, name); + int ret = 0; + + if (!IS_ERR(chan)) + ret = devm_add_action_or_reset(dev, dmaenginem_release_channel, chan); + + if (ret) + return ERR_PTR(ret); + + return chan; +} +EXPORT_SYMBOL_GPL(devm_dma_request_chan); + /** * dmaengine_get - register interest in dma_channels */ |