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-rw-r--r--drivers/dma/dmaengine.c16
-rw-r--r--include/linux/dmaengine.h52
2 files changed, 66 insertions, 2 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7344f5d..dc003a3 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 b058d63..9b91d34 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);
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