diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dmaengine.h | 58 |
1 files changed, 35 insertions, 23 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 3de1cf71031..a3b6035b6c8 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -29,20 +29,32 @@ #include <linux/dma-mapping.h> /** - * enum dma_event - resource PNP/power managment events + * enum dma_state - resource PNP/power managment state * @DMA_RESOURCE_SUSPEND: DMA device going into low power state * @DMA_RESOURCE_RESUME: DMA device returning to full power - * @DMA_RESOURCE_ADDED: DMA device added to the system + * @DMA_RESOURCE_AVAILABLE: DMA device available to the system * @DMA_RESOURCE_REMOVED: DMA device removed from the system */ -enum dma_event { +enum dma_state { DMA_RESOURCE_SUSPEND, DMA_RESOURCE_RESUME, - DMA_RESOURCE_ADDED, + DMA_RESOURCE_AVAILABLE, DMA_RESOURCE_REMOVED, }; /** + * enum dma_state_client - state of the channel in the client + * @DMA_ACK: client would like to use, or was using this channel + * @DMA_DUP: client has already seen this channel, or is not using this channel + * @DMA_NAK: client does not want to see any more channels + */ +enum dma_state_client { + DMA_ACK, + DMA_DUP, + DMA_NAK, +}; + +/** * typedef dma_cookie_t - an opaque DMA cookie * * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code @@ -104,7 +116,6 @@ struct dma_chan_percpu { /** * struct dma_chan - devices supply DMA channels, clients use them - * @client: ptr to the client user of this chan, will be %NULL when unused * @device: ptr to the dma device who supplies this channel, always !%NULL * @cookie: last cookie value returned to client * @chan_id: channel ID for sysfs @@ -112,12 +123,10 @@ struct dma_chan_percpu { * @refcount: kref, used in "bigref" slow-mode * @slow_ref: indicates that the DMA channel is free * @rcu: the DMA channel's RCU head - * @client_node: used to add this to the client chan list * @device_node: used to add this to the device chan list * @local: per-cpu pointer to a struct dma_chan_percpu */ struct dma_chan { - struct dma_client *client; struct dma_device *device; dma_cookie_t cookie; @@ -129,11 +138,11 @@ struct dma_chan { int slow_ref; struct rcu_head rcu; - struct list_head client_node; struct list_head device_node; struct dma_chan_percpu *local; }; + void dma_chan_cleanup(struct kref *kref); static inline void dma_chan_get(struct dma_chan *chan) @@ -158,26 +167,31 @@ static inline void dma_chan_put(struct dma_chan *chan) /* * typedef dma_event_callback - function pointer to a DMA event callback + * For each channel added to the system this routine is called for each client. + * If the client would like to use the channel it returns '1' to signal (ack) + * the dmaengine core to take out a reference on the channel and its + * corresponding device. A client must not 'ack' an available channel more + * than once. When a channel is removed all clients are notified. If a client + * is using the channel it must 'ack' the removal. A client must not 'ack' a + * removed channel more than once. + * @client - 'this' pointer for the client context + * @chan - channel to be acted upon + * @state - available or removed */ -typedef void (*dma_event_callback) (struct dma_client *client, - struct dma_chan *chan, enum dma_event event); +struct dma_client; +typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client, + struct dma_chan *chan, enum dma_state state); /** * struct dma_client - info on the entity making use of DMA services * @event_callback: func ptr to call when something happens - * @chan_count: number of chans allocated - * @chans_desired: number of chans requested. Can be +/- chan_count - * @lock: protects access to the channels list - * @channels: the list of DMA channels allocated + * @cap_mask: only return channels that satisfy the requested capabilities + * a value of zero corresponds to any capability * @global_node: list_head for global dma_client_list */ struct dma_client { dma_event_callback event_callback; - unsigned int chan_count; - unsigned int chans_desired; - - spinlock_t lock; - struct list_head channels; + dma_cap_mask_t cap_mask; struct list_head global_node; }; @@ -285,10 +299,9 @@ struct dma_device { /* --- public DMA engine API --- */ -struct dma_client *dma_async_client_register(dma_event_callback event_callback); +void dma_async_client_register(struct dma_client *client); void dma_async_client_unregister(struct dma_client *client); -void dma_async_client_chan_request(struct dma_client *client, - unsigned int number); +void dma_async_client_chan_request(struct dma_client *client); dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, void *src, size_t len); dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan, @@ -299,7 +312,6 @@ dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan, void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, struct dma_chan *chan); - static inline void async_tx_ack(struct dma_async_tx_descriptor *tx) { |