diff options
| -rw-r--r-- | drivers/dma/dmaengine.c | 16 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 52 |
2 files changed, 66 insertions, 2 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 7344f5dbd501..dc003a3a787d 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -169,7 +169,12 @@ static void dma_client_chan_alloc(struct dma_client *client) enum dma_state_client ack; /* Find a channel */ - list_for_each_entry(device, &dma_device_list, global_node) + list_for_each_entry(device, &dma_device_list, global_node) { + /* Does the client require a specific DMA controller? */ + if (client->slave && client->slave->dma_dev + && client->slave->dma_dev != device->dev) + continue; + list_for_each_entry(chan, &device->channels, device_node) { if (!dma_chan_satisfies_mask(chan, client->cap_mask)) continue; @@ -191,6 +196,7 @@ static void dma_client_chan_alloc(struct dma_client *client) return; } } + } } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) @@ -289,6 +295,10 @@ static void dma_clients_notify_removed(struct dma_chan *chan) */ void dma_async_client_register(struct dma_client *client) { + /* validate client data */ + BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) && + !client->slave); + mutex_lock(&dma_list_mutex); list_add_tail(&client->global_node, &dma_client_list); mutex_unlock(&dma_list_mutex); @@ -365,6 +375,10 @@ int dma_async_device_register(struct dma_device *device) !device->device_prep_dma_memset); BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt); + BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) && + !device->device_prep_slave_sg); + BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) && + !device->device_terminate_all); BUG_ON(!device->device_alloc_chan_resources); BUG_ON(!device->device_free_chan_resources); diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index b058d6360383..9b91d341e1fa 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -89,10 +89,23 @@ enum dma_transaction_type { DMA_MEMSET, DMA_MEMCPY_CRC32C, DMA_INTERRUPT, + DMA_SLAVE, }; /* last transaction type for creation of the capabilities mask */ -#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1) +#define DMA_TX_TYPE_END (DMA_SLAVE + 1) + +/** + * enum dma_slave_width - DMA slave register access width. + * @DMA_SLAVE_WIDTH_8BIT: Do 8-bit slave register accesses + * @DMA_SLAVE_WIDTH_16BIT: Do 16-bit slave register accesses + * @DMA_SLAVE_WIDTH_32BIT: Do 32-bit slave register accesses + */ +enum dma_slave_width { + DMA_SLAVE_WIDTH_8BIT, + DMA_SLAVE_WIDTH_16BIT, + DMA_SLAVE_WIDTH_32BIT, +}; /** * enum dma_ctrl_flags - DMA flags to augment operation preparation, @@ -119,6 +132,32 @@ enum dma_ctrl_flags { typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t; /** + * struct dma_slave - Information about a DMA slave + * @dev: device acting as DMA slave + * @dma_dev: required DMA master device. If non-NULL, the client can not be + * bound to other masters than this. + * @tx_reg: physical address of data register used for + * memory-to-peripheral transfers + * @rx_reg: physical address of data register used for + * peripheral-to-memory transfers + * @reg_width: peripheral register width + * + * If dma_dev is non-NULL, the client can not be bound to other DMA + * masters than the one corresponding to this device. The DMA master + * driver may use this to determine if there is controller-specific + * data wrapped around this struct. Drivers of platform code that sets + * the dma_dev field must therefore make sure to use an appropriate + * controller-specific dma slave structure wrapping this struct. + */ +struct dma_slave { + struct device *dev; + struct device *dma_dev; + dma_addr_t tx_reg; + dma_addr_t rx_reg; + enum dma_slave_width reg_width; +}; + +/** * struct dma_chan_percpu - the per-CPU part of struct dma_chan * @refcount: local_t used for open-coded "bigref" counting * @memcpy_count: transaction counter @@ -208,11 +247,14 @@ typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client, * @event_callback: func ptr to call when something happens * @cap_mask: only return channels that satisfy the requested capabilities * a value of zero corresponds to any capability + * @slave: data for preparing slave transfer. Must be non-NULL iff the + * DMA_SLAVE capability is requested. * @global_node: list_head for global dma_client_list */ struct dma_client { dma_event_callback event_callback; dma_cap_mask_t cap_mask; + struct dma_slave *slave; struct list_head global_node; }; @@ -269,6 +311,8 @@ struct dma_async_tx_descriptor { * @device_prep_dma_zero_sum: prepares a zero_sum operation * @device_prep_dma_memset: prepares a memset operation * @device_prep_dma_interrupt: prepares an end of chain interrupt operation + * @device_prep_slave_sg: prepares a slave dma operation + * @device_terminate_all: terminate all pending operations * @device_issue_pending: push pending transactions to hardware */ struct dma_device { @@ -304,6 +348,12 @@ struct dma_device { struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)( struct dma_chan *chan, unsigned long flags); + struct dma_async_tx_descriptor *(*device_prep_slave_sg)( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_data_direction direction, + unsigned long flags); + void (*device_terminate_all)(struct dma_chan *chan); + enum dma_status (*device_is_tx_complete)(struct dma_chan *chan, dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used); |
